JP2007167994A - Cutting device with fine adjustment function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent lowering of a service life of a cartridge, a washer and a bush due to turning torque applied to a cutting blade. <P>SOLUTION: In this cutting device with a fine adjustment function, the cartridge 73 having a cutting blade 76 at the tip is inserted in a cylindrical bush 61 mounted on a tool body 51, the washer 86 is fixed to the proximal end of the cartridge 73, an energizing member 93 is interposed between the washer 86 and the bush 61, an adjusting nut 68 screwed on the cartridge 73 is turned to project and recess the cartridge 73, and the projection amount of the cutting blade 76 from the tip of the bush 61 is finely adjusted. The cartridge 73 includes: a cutting blade part 74 provided with the cutting blade 76; a male screw part 80 connected to the proximal end of the cutting blade part 74 and inserted into the adjusting nut 68; and a shaft part 82 extended from the proximal end of the male screw part 80 along the axis L and connected to the washer 86, wherein the tip of the cutting blade 76 is disposed on the axis L. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fine adjustment type cutting tool capable of fine adjustment of the protrusion amount of a cutting blade.

  Generally, in boring, roughing, intermediate finishing, and precision finishing may be combined. In particular, precision boring requires high precision such as the dimensional accuracy of the hole and surface roughness of the processing surface. Therefore, fine adjustment of the protruding amount of the cutting edge in the cutting tool is required each time. As a cutting tool to cope with such fine adjustment of the protruding amount of the cutting blade, a fine adjustment type cutting tool disclosed in Patent Document 1 is provided.

FIG. 4 shows a line bar as an example of a conventional fine-tuning cutting tool. FIG. 5 shows details of the cutting edge portion of the line bar.
The line bar 1 has a long cylindrical tool body 2, and a plurality of notches 3 having a depth D recessed inward in the radial direction are provided on the outer peripheral surface thereof in the direction of the central axis O. An insertion hole extending in the radial direction of the tool body 2 is formed on the bottom surface of the notch 3, and a cylindrical bush 11 is detachably inserted into the insertion hole.

  An annular large-diameter portion 12 projecting radially outward is formed on the outer peripheral portion of the bush 11 on the distal end side (right side in FIG. 5). The large-diameter portion 12 includes a proximal end side (FIG. 4). A recess 13 having a circular cross section that is recessed toward the left side in FIG. An insertion hole 14 that opens to the distal end side and a storage hole 15 that opens to the proximal end side are provided in the inner peripheral portion of the bush 11, and between the insertion hole 14 and the storage hole 15, there is a bush. An annular support wall 16 protruding toward the inner peripheral side of 11 is formed. In addition, a pair of guide projections 17 projecting toward the base end side are formed on the base end side of the bush 11 at positions facing each other by 180 °.

  A cylindrical adjusting nut 18 is fitted into the insertion hole 14. A flange 19 protruding radially outward is formed on the outer peripheral portion on the distal end side of the adjustment nut 18, and a female screw portion 20 is formed on the inner peripheral portion on the proximal end side of the adjustment nut 18. The adjusting nut 18 accommodates the flange portion 19 in the recess 13 of the bush 11 so that the surface facing the proximal end of the flange portion 19 and the bottom surface of the recess 13 come into contact with each other in the insertion hole 14. It is inserted. Further, a hooking portion 21 for hooking a work tool such as a spanner when the adjustment nut 18 is rotated is formed at a tip side portion from the flange portion 19.

  The cartridge 22 inserted into the bush 11 and the adjusting nut 18 has a substantially cylindrical shape whose outer shape extends along the axis L, and a cutting edge portion 23 is provided on the tip side (right side in FIG. 5). An insert mounting seat 24 is formed on the cutting blade portion 23, and an insert 25 made of a hard material such as cemented carbide is detachably mounted by a mounting screw 26, and a cutting blade 27 is disposed at the tip of the cartridge 22. Has been. Here, the insert has a polygonal flat plate shape (triangular flat plate shape in FIG. 5), and the corners of the polygon can be used sequentially.

On the proximal end side of the cutting edge portion 23, a contact portion 29 is provided which is in contact with the inner peripheral surface of the adjustment nut 18 via a neck portion 28 having a one-step small diameter. A male screw portion 30 is formed at the proximal end portion of the contact portion 29, and a blank portion 31 that is recessed radially inward is provided between the male screw portion 30 and the contact portion 29.
On the base end side of the male screw portion 30, a shaft portion 32 that passes through the support wall 16 and is inserted into the housing hole 15 side of the bush 11 is provided. A protrusion 33 is formed which extends in a direction perpendicular to the axis L and has a substantially V-shaped cross section. The shaft portion 32 is provided with a clamp screw hole 34 that is open at the base end surface and extends along the axis L.

  A washer 35 is disposed on the proximal end side of the bush 11 so as to close the opening of the storage hole 15. The washer 35 includes a washer main body 36 having a substantially disc shape, and an insertion shaft 37 projecting from the vicinity of the center of the washer main body 36 toward the distal end side. The cartridge 22 is disposed on the distal end surface of the insertion shaft 37. A concave groove 38 having a substantially V-shaped cross section that can be engaged with the protruding portion 33 of the shaft portion 32 is formed. A clamp screw insertion hole 39 is formed so as to penetrate the washer body 36 and the insertion shaft 37. Further, the washer main body 36 is formed with a pair of guide grooves 40, each of which is recessed in a U-shape with a part of its outer peripheral surface facing the tip side, at positions facing each other by 180 °.

  The washer 35 is formed by screwing a clamp screw 41 inserted into the clamp screw insertion hole 39 into a clamp screw hole 34 formed in the shaft portion 32 of the cartridge 22. It is fixed so as to close the opening. At this time, the guide projection 17 of the bush 11 is arranged to engage with the guide groove 40 of the washer 35, and the washer 35 is movable along the axis L together with the cartridge 22.

  A plurality of disc springs 42 are inserted as biasing members into the storage hole 15 portion closed by the washer 35, and the washer 35, the cartridge 22, and the adjustment nut are elastically applied to the disc springs 42. 18 is always urged in a direction of being drawn toward the base end side. Here, in this fine adjustment type cutting tool, the axial length L direction length S of the storage hole 15 in which the plurality of stacked disc springs 42 are stored is S = the axial length L direction length B of the bush 11. It is comprised so that it may become 0.33xB.

The line bar 1 is inserted into a pilot hole provided so as to penetrate the material to be cut, and rotated around the central axis O in a state where both ends of the line bar 1 are supported by a machine tool. A plurality of cutting edges 27 projecting from the outer peripheral surface 2 are used to cut a plurality of locations on the inner peripheral surface of the prepared hole.
In this line bar 1, the cartridge 22 can be moved back and forth in the direction of the axis L according to the screw pitch of the male screw portion 30 and the female screw portion 20 by rotating the adjustment nut 18 with a work tool such as a spanner. The amount of protrusion of the cutting edge 27 can be finely adjusted. Here, in this fine adjustment type cutting tool, the engagement of the cartridge base end protrusion and the groove of the washer tip and the engagement of the washer guide groove and the guide protrusion of the bush, The rotation around the axis L is prevented, and the protrusion amount of the cutting blade 27 can be finely adjusted without changing the angle of the cutting blade 27.
Japanese Patent Application Laid-Open No. 08-66810 Japanese Patent No. 2950074

  By the way, in this fine adjustment type cutting tool, as shown in FIG. 5, since the polygonal flat plate-like insert is attached, the tip of the cutting blade is disposed at a position away from the axis L of the cartridge. . Further, when the cutting edge of such a polygonal flat plate-like insert is to be arranged at the center of the axis L of the cartridge, it is placed so that the corner of the polygonal surface is on the axis L. The length in the direction of the axis L becomes longer.

  When the cutting blade is disposed at a position away from the axis, rotational torque acts on the cartridge due to cutting resistance. This rotational torque is received by the engaging portion of the protrusion on the base end side of the cartridge and the concave groove of the washer tip, the engaging portion of the guide groove of the washer and the guide convex portion of the bush, and the fixing screw of the bush. However, when a large amount of rotational torque is applied, these engaging portions may be worn or damaged, and the life of these cartridges, washers, and bushes may be shortened.

  Further, when the length in the axis L direction from the bush front end surface to the tip end of the cutting blade is long, it is necessary to form the notch portion of the tool body deeply, and the rigidity of the tool body is insufficient. Then, when this tool body is rotated at a high speed, there is a problem that the tool body itself is shaken and cutting cannot be performed with high dimensional accuracy.

The present invention has been made in consideration of such circumstances, and a first object of the invention is to extend the life of the cartridge, washer and bush by suppressing the rotational torque applied to the cutting blade. .
A second object of the present invention is to secure the rigidity of the tool body by shortening the length in the axis L direction from the bush tip surface to the tip of the cutting blade.

  In order to solve this problem, in the present invention, a cartridge having a columnar shape extending along an axis and having a cutting blade at the tip is inserted into an inner peripheral hole of a cylindrical bush detachably attached to a tool body, A washer is fixed to the base end side of the cartridge, and a biasing member for biasing the cartridge toward the base end side is interposed between the washer and the bush via the washer. In the fine-adjustable cutting tool capable of causing the cartridge to protrude and retract in the axial direction by rotating an adjustment nut screwed to the blade, and finely adjusting a protruding amount of the cutting blade from the bush tip. A cutting blade portion provided with the cutting blade, a male screw portion connected to the base end side of the cutting blade portion and screwed to the adjusting nut, and a base end side of the male screw portion from the base end side to the axis line Extending along And a shaft portion connected to the serial washer, the tip of the cutting edge is characterized in that it is arranged on the axis.

  In the fine-adjustable cutting tool having this configuration, the tip of the cutting blade is disposed on the axis of the cartridge, and therefore, a rotational torque is less likely to be generated by cutting resistance acting on the cutting blade. Accordingly, it is possible to prevent a load from being applied to the engaging portion between the cartridge and the washer, the engaging portion between the washer and the bush, the connecting portion between the bush and the tool body, and the life of the cartridge, the washer and the bush is extended. Can do.

Here, the mounting hole that opens toward the tip of the cutting blade portion is formed in the cartridge, and a cutting tool that has a columnar shape and has a cutting blade at the tip is inserted into the mounting hole. The tip of the blade can be placed on the axis. Furthermore, if the cutting edge wears out, it can be reused by regrinding the tip of the cutting tool. It can be used as a fine-tuning cutting tool.
Further, since the cutting blade can be arranged without mounting a flat plate-like insert, the axial distance from the bush front end surface to the cutting blade front end can be reduced. Therefore, the depth of the notch portion of the tool body can be reduced, and the rigidity of the tool body can be ensured to prevent deflection during high-speed rotation.

  Further, the axial length A from the front end surface of the bush to the front end of the cutting blade is within a range of A: B = 4: 8 to 4:10 with respect to the axial length B of the bush. By setting to, the axial distance from the bush tip surface to the cutting blade tip can be reliably reduced, the depth of the notch formed in the tool body is reduced, and the rigidity of the tool body is ensured. be able to.

  Further, the bush is formed with a support portion that extends inward in the radial direction of the inner peripheral hole to support the cartridge, and the outer peripheral surface on the front end side of the shaft portion is fitted with the support portion of the bush. By forming the mating surface and directly fitting the bush and the cartridge, the cartridge does not rattle due to the cutting force acting on the cutting edge, and the fluctuation of the cutting edge can be prevented.

  By directly fitting the cartridge to the bush in this manner, it is not necessary to form a fitting portion on the tip side of the male screw portion of the cartridge unlike the conventional fine adjustment type cutting tool, and the fitting is also performed on the adjustment nut. There is no need to provide a fitting part and a fitting part, and the axial length of the entire adjustment nut can be shortened. Therefore, the axial length of the portion that accommodates the adjustment nut on the distal end side of the bush can be reduced, and the axial length of the storage hole that opens on the proximal end side of the bush can be increased. Moreover, even if the axial length of the storage hole is increased in this way, the length of the male screw portion of the cartridge can be secured, so the moving range of the cartridge in the axial direction is large and the adjustment of the protruding amount of the cutting blade is ensured. It can be carried out.

  Moreover, the axial direction length of the urging | biasing member which can be arrange | positioned in a storage hole can be lengthened by lengthening the axial direction length of a storage hole. Therefore, the adjustment nut and the cartridge can be strongly urged toward the proximal end side by the urging member, the rattling of the cartridge and the adjustment nut can be reduced, and the protrusion amount of the cutting blade can be adjusted with high accuracy. In addition, it is possible to reliably prevent the cutting blade from being shaken by the cutting resistance acting on the cutting blade portion.

  Further, the adjustment nut is provided with a latching portion on which a pivoting means for pivoting the adjustment nut is engaged, and when the cartridge is viewed from the front end side in the axial direction, the cutting blade portion is disposed on the latching portion. For example, a work tool can be inserted from the front end side in the direction of the axis L and can be engaged with the hook portion, and the work tool can be inserted into the notch and rotated. It is not necessary to secure the space, and the size of the notch portion of the tool body can be reduced, and the rigidity of the tool body can be further improved.

Further, by setting the axial length S of the storage hole to S ≧ 0.5 × B with respect to the axial length B of the bush, a range in which the cartridge can move in the axial direction is secured. It is possible to adjust the protrusion amount of the cutting blade more reliably. Further, the adjustment nut and the cartridge can be strongly urged toward the base end side by the urging member, the rattling between the cartridge and the adjustment nut can be reduced, and the amount of protrusion of the cutting blade can be adjusted accurately. In addition, it is possible to reliably prevent the cutting blade from being shaken by the cutting resistance acting on the cutting blade portion.
Further, by setting the axial length S of the storage hole to S ≦ 0.8 × B with respect to the axial length B of the bush, the thickness of the support wall of the bush can be secured, and the bush It is possible to prevent a reduction in rigidity of itself.

  As described above, according to the present invention, it is possible to extend the life of the cartridge, the washer, and the bush by suppressing the rotational torque applied to the cutting blade. In addition, the length in the direction of the axis L from the front end surface of the bush to the front end of the cutting blade can be shortened to ensure the rigidity of the tool body.

Below, the fine adjustment type cutting tool which is embodiment of this invention is demonstrated using attached drawing. FIG. 1 to FIG. 3 show details of the cutting edge of a fine-tuning cutting tool according to an embodiment of the present invention.
In this finely adjustable cutting tool, a notch 52 having a depth D recessed inside the tool body 51 is formed on the outer peripheral surface of the tool body 51, and a fitting hole 53 is formed in the bottom surface of the notch 52. Yes. The fitting hole 53 is detachably mounted with a bush 61 having a substantially cylindrical shape.

  An annular large-diameter portion 62 projecting outward in the radial direction is provided on the outer peripheral portion of the bush 61 on the distal end side (right side in FIG. 1). The large-diameter portion 62 opens to the distal end side. A recess 63 that is recessed toward the base end side (left side in FIG. 1) is formed. An annular support wall 64 projecting toward the inner peripheral side of the bush 61 is formed at the tip side portion of the inner peripheral hole of the bush 61, and an insertion hole 65 is formed on the inner peripheral side of the support wall 64. Yes. The surface facing the tip side of the support wall 64 is the bottom surface of the recess 63. In addition, a housing hole 66 that opens toward the base end side is provided in the inner peripheral portion of the bush 61, and a surface facing the base end side of the support wall 64 is a bottom surface of the storage hole 66. Further, as shown in FIGS. 1 and 3, a pair of guide convex portions 67 projecting toward the base end side are formed on the base end side of the bush 61 at positions facing each other by 180 ° with the axis L interposed therebetween. ing.

An adjustment nut 68 is fitted into the recess 63. The adjustment nut 68 has a multistage cylindrical shape, and includes a small diameter portion 69 fitted into the concave portion 63 and a nut body 70 having a diameter larger than that of the small diameter portion 69. A surface of the nut body 70 facing the proximal end is in contact with the distal end surface of the bush 61. The outer peripheral surface of the front end side of the nut body 70 has a hexagonal shape as shown in FIG. 2, and is a latching portion 71 to which a working tool such as a spanner for rotating the adjusting nut 68 is engaged. Yes.
Further, the inner diameter of the inner peripheral hole of the adjustment nut 68 is made larger than the inner diameter of the insertion hole of the bush 61, and a female screw portion 72 is formed on the inner peripheral surface thereof.

As shown in FIGS. 1 and 2, the cartridge 73 inserted into the adjustment nut 68 and the bush 61 has a multistage cylindrical shape whose outer shape extends along the axis L, and a cutting edge portion 74 is formed at the tip side thereof. Is formed. The cutting blade portion 74 is formed with a mounting hole 75 having a circular cross section that opens toward the distal end side and extends along the axis L of the cartridge 73. A bite 77 having a substantially cylindrical shape with an outer diameter that can be inserted into the mounting hole 75 and having a cutting edge 76 formed at the tip is inserted into the mounting hole 75. A pressed surface 78 having a flat surface is formed on the cutting tool 77, and the pressed surface 78 is fixed by being pressed by a mounting screw 79.
Here, in the present embodiment, the cutting edge portion 74 including the cutting tool 77 is, as shown in FIG. 2, the outer periphery of the nut body 70 that forms the latching portion 71 of the adjustment nut 68 as viewed from the axis L direction. It arrange | positions so that it may be located inside a surface.

  A male screw portion 80 is formed on the base end side of the cutting blade portion 74, and the bush 61 is inserted through a nut portion 81 recessed inward in the radial direction further on the base end side of the male screw portion 80. A shaft portion 82 to be inserted into the hole 65 and the storage hole 66 is provided. Here, on the base end side of the cutting blade portion 74, the male screw portion 80 is formed to have the maximum outer diameter, and the male screw portion 80 and the female screw portion 72 are screwed together to adjust. The cartridge 73 is attached to the nut 68, and the cartridge 73 and the adjustment nut 68 are not fitted.

  The outer peripheral surface of the tip side portion of the shaft portion 82 is a surface facing the inner peripheral side of the support wall 64 of the bush 61, that is, a fitting surface 83 fitted to the inner peripheral surface of the insertion hole 65. ing. That is, the outer peripheral surface of the shaft portion 82 is a cylindrical surface having a constant outer diameter centered on the axis L, while the inner peripheral surface of the insertion hole 65 is a cylindrical surface having a constant inner diameter, and these inner and outer diameters are fitted to each other. The fitting surface 83 on the outer periphery of the shaft portion 82 is supported so as to be in sliding contact with the inner periphery of the insertion hole 65 over the entire circumference.

  On the base end surface of the shaft portion 82, a ridge portion 84 extending in a direction perpendicular to the axis L and having a substantially V-shaped cross section is formed. Further, the cartridge 73 is formed with a clamp screw hole 85 that opens to the base end surface and extends toward the distal end side along the axis L.

  A washer 86 is provided on the base end side of the bush 61 so as to close the opening of the storage hole 66. The washer 86 includes a washer main body 87 having a substantially disc shape and an insertion shaft 88 projecting from the vicinity of the center of the washer main body 87 toward the front end side. A concave groove 89 having a substantially V-shaped cross section that can be engaged with the protruding portion 84 of the shaft portion 82 of the shaft 73 is formed. Further, a clamp screw insertion hole 90 is formed so as to penetrate the washer main body 87 and the insertion shaft 88. Further, as shown in FIG. 3, the washer body 87 has a pair of guide grooves 91 in which a part of the outer peripheral surface is recessed in a U shape toward the distal end side and the radially inner side, with the axis L interposed therebetween. ° It is formed at the position facing each other.

  The washer 86 is formed by screwing a clamp screw 92 inserted into the clamp screw insertion hole 90 into a clamp screw hole 85 formed in the shaft portion 82 of the cartridge 73, so that the storage hole 66 of the bush 61 is inserted. It is fixed so as to close the opening. At this time, the guide convex portion 67 of the bush 61 is disposed so as to engage with the guide groove 91 of the washer 86, and the washer 86 is movable along the axis L together with the cartridge 73.

A plurality of disc springs 93 are inserted as biasing members into the storage hole 66 portion closed by the washer 86, and the washer 86, the cartridge 73, and the adjusting nut are elastically applied to the disc springs 93. 68 is always biased in a direction of being pulled toward the base end side.
In the present embodiment, the axial length L direction length S of the storage hole 66 of the bush 61 in which the plurality of disc springs 93 are stored is 0.5 × B ≦ the axial length L direction B of the bush 61. It is set to be in the range of S ≦ 0.8 × B, and more specifically, S = 0.67 × B.

  In the fine-adjusting cutting tool configured as described above, the cutting edge 76 formed at the tip of the cutting tool 77 is disposed on the axis L of the cartridge 73. In this embodiment, the length A in the axial direction L from the front end surface of the bush 61 to the front end of the cutting edge 76 is A: B = 4: 8-4 with respect to the length L in the axial direction L of the bush 61. : It is set to be within the range of 10.

The cartridge 73 is fitted and fixed together with the bush 61 in a fitting hole 53 provided in the tool main body 51, and the cutting edge 76 is slightly from the outer peripheral surface of the tool main body 51, in this embodiment, the tip of the bush 61. It is arranged so as to protrude by the difference (A−D) between the length A in the axis L direction from the surface to the tip of the cutting edge 76 and the depth D of the notch 52.
The tool body 51 is inserted into a prepared hole formed in advance in the material to be cut and cut by the cutting blade 76 to form a machining hole having a predetermined inner diameter.

  In order to improve the dimensional accuracy of the machining hole, it is necessary to adjust the protruding amount of the cutting blade 76 from the tool body 51. In the fine adjustment type cutting tool according to the present embodiment, a male tool 80 and a female screw 72 are obtained by rotating a work tool such as a spanner on a hook 71 of the adjustment nut 68 and rotating the adjustment nut 68. The cartridge 73 moves so as to be able to advance and retreat in the direction of the axis L according to the screw pitch, and the protruding amount of the cutting blade 76 can be adjusted with high accuracy.

  According to the fine adjustment type cutting tool of this embodiment, since the tip of the cutting edge 76 is disposed on the axis L of the cartridge 73, the rotational torque generated in the cartridge 73 by the cutting resistance acting on the cutting edge 76 is reduced. Can be suppressed. Therefore, the engaging portion between the protruding portion 84 of the cartridge 73 and the concave groove 89 of the washer 86, the engaging portion of the guide groove 91 of the washer 86 and the guide convex portion 67 of the bush 61, and the bush 61 and the tool body 51. It is possible to prevent an excessive load from being applied to the coupling portion, and to extend the life of the washer 86, the bush 61, and the cartridge 73.

  A mounting hole 75 that opens toward the tip of the cutting edge portion 74 is formed in the cartridge 73, and a cutting tool 76 having a cylindrical column shape and having a cutting edge 76 is inserted into the mounting hole 75 and fixed. Therefore, the tip of the cutting blade 76 can be reliably arranged on the axis L. Further, when the cutting edge 76 is worn, it can be reused by re-polishing the tip of the cutting tool 77. Even if the length of the cutting tool 77 is shortened by re-polishing, the protruding amount of the cutting blade 76 is reduced. Can be used as a fine-tuning cutting tool.

  Moreover, since the cutting blade 76 can be arranged without mounting a flat insert, the distance in the axis L direction from the front end surface of the bush 61 to the front end of the cutting blade 76 can be reduced. In the present embodiment, the length A in the axis L direction from the tip surface of the bush 61 to the tip of the cutting edge 76 is A: B = 4: 8-4 with respect to the length L in the axis direction L of the bush 61. Since the depth D of the notch 52 of the tool body 51 can be reduced, the rigidity of the tool body 51 can be secured. Therefore, the tool body 51 can be prevented from swinging when rotated at high speed, and the machining hole can be formed with high accuracy.

Further, since the cartridge 73 having the cutting edge portion 74 is directly fitted to the support wall 64 of the bush 61, the cartridge 73 is not rattled by the cutting resistance acting on the cutting edge portion 74, and the cutting edge 76 can be reliably prevented.
Since the cartridge 73 is directly fitted to the bush 61 in this way, it is necessary to form a portion for fitting the adjustment nut 68 on the distal end side of the male screw portion 80 of the cartridge 73 as in the conventional fine adjustment type cutting tool. The length of the entire adjustment nut 68 in the axis L direction can be shortened while the length of the female screw portion 72 of the adjustment nut 68 is secured, and the recess 63 formed on the distal end side of the bush 61 is made shallower. be able to. Therefore, even if the length of the accommodation hole 66 of the bush 61 is increased in the direction of the axis L, the movement range of the cartridge 73 in the direction of the axis L can be secured, and the amount of protrusion of the cutting blade 76 can be adjusted reliably. it can.

  Further, by increasing the length of the storage hole 66 in the axis L direction, the number of disc springs 93 that can be disposed in the storage hole 66 can be increased. Can be strongly urged toward Accordingly, rattling between the male screw portion 80 and the female screw portion 72 is reduced, the amount of protrusion of the cutting blade 76 can be adjusted with high accuracy, and the cutting force acting on the cutting blade portion 74 can be applied to the cutting blade 76. It is possible to reliably prevent the occurrence of shake.

Specifically, the axial length L direction length S of the storage hole 66 that stores the disc spring 93 is 0.5 × B ≦ S ≦ 0.8 × B with respect to the axial length L direction B of the bush 61. Since it is set within the range, the movable range of the cartridge 73 in the direction of the axis L can be increased, the amount of protrusion of the cutting blade 76 can be adjusted reliably, and the support wall 64 of the bush 61 can be adjusted. The wall thickness and the washer 86 can be secured.
In particular, in this embodiment, S = 0.67 × B is set, and the axial length L direction length S of the disc spring 93 is doubled as compared with the conventional fine adjustment type cutting tool shown in FIG. Therefore, the adjustable range is increased, and the adjustment nut 68 and the cartridge 73 can be strongly urged toward the base end side.

  Further, since the cutting edge portion 74 including the cutting tool 77 is disposed inside the latching portion 71 of the nut body 70 of the adjustment nut 68, even if a working tool such as a spanner is inserted from the front end side of the cartridge 73. The adjusting nut 68 can be rotated by engaging the work tool with the hook 71 without the interference between the cutting edge portion 74 and the work tool. Therefore, it is not necessary to secure a space for rotating the work tool, the size of the notch 52 of the tool body 51 can be reduced, and the rigidity of the tool body 51 can be further improved.

The fine adjustment type cutting tool according to the embodiment of the present invention has been described above. However, the present invention is not limited to this embodiment, and can be appropriately changed without departing from the technical idea of the present invention.
For example, although a plurality of disc springs are stacked as the biasing member, the present invention is not limited to this, and a coil spring or the like may be used.

  Further, by forming a protrusion having a V-shaped cross section on the base end surface of the cartridge shaft, and forming a concave groove having a V-shaped cross section on the front end surface of the washer insertion shaft, and fitting them together Although it has been described that the cartridge is prevented from rotating, the present invention is not limited to this. For example, the concave groove may be a U-shaped key groove.

It is side surface sectional drawing of the fine adjustment type cutting tool which is embodiment of this invention. It is a X direction arrow line view in FIG. It is a Y direction arrow directional view in FIG. It is a side view of the conventional fine adjustment type cutting tool. It is side surface sectional drawing of the cartridge with which the fine adjustment type cutting tool shown in FIG. 4 was equipped.

Explanation of symbols

51 Tool body 61 Bush 66 Storage hole 68 Adjustment nut 71 Locking portion 73 Cartridge 74 Cutting blade portion 75 Mounting hole 76 Cutting blade 77 Bit 80 Male screw portion 82 Shaft portion 86 Washer 93 Belleville spring (biasing member)

Claims (6)

A cartridge having a columnar shape extending along the axis and having a cutting blade at the tip is inserted into an inner peripheral hole of a cylindrical bush detachably attached to the tool body, and a washer is fixed to the base end side of the cartridge, Between the washer and the bush, an urging member for urging the cartridge toward the base end side is interposed via the washer, and an adjustment nut screwed to the cartridge is rotated. In the fine adjustment type cutting tool that allows the cartridge to protrude and retract in the axial direction and finely adjust the protruding amount of the cutting blade from the bush tip,
The cartridge includes a cutting blade portion provided with the cutting blade, a male screw portion connected to a proximal end side of the cutting blade portion and screwed with the adjustment nut, and a proximal end side of the male screw portion. A fine-adjustable cutting tool comprising: a shaft portion extending along the axis and connected to the washer; and a tip of the cutting blade disposed on the axis.   The cartridge is formed with an attachment hole that opens toward the tip of the cutting blade portion, and a cutting tool having a columnar shape and having the cutting blade at the tip is inserted into the attachment hole. The fine adjustment type cutting tool according to claim 1.   The axial length A from the front end surface of the bush to the front end of the cutting edge is set within a range of A: B = 4: 8 to 4:10 with respect to the axial length B of the bush. The fine-adjustable cutting tool according to claim 1 or 2, wherein the fine-adjustable cutting tool is provided.   The bush is formed with a support portion that extends inward in the radial direction of the inner peripheral hole to support the cartridge, and a front end side outer peripheral surface of the shaft portion is fitted into the support portion of the bush. The fine-adjustable cutting tool according to any one of claims 1 to 3, wherein the cartridge is directly fitted into the bush. The adjustment nut is provided with a latching portion to which a rotation means for rotating the adjustment nut is engaged,
5. The fine adjustment type according to claim 1, wherein the cutting blade portion is disposed inside an outer peripheral surface of the hook portion when the cartridge is viewed from the axial direction. Cutting tools.   The bush is formed with a storage hole for storing the biasing member, and the axial length S of the storage hole is 0.5 × B ≦ S with respect to the axial length B of the bush. The fine-adjustable cutting tool according to any one of claims 1 to 5, wherein the fine-cutting cutting tool is within a range of ≦ 0.8 × B.

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