JP5477918B2 - Rotating tool - Google Patents

Description

  The present invention relates to a rotary tool provided with a head portion for processing a workpiece at a front end portion of a rotary shaft that is rotationally driven.

  Conventionally, as a rotating tool of this type, a cylindrical rotating shaft that is rotationally driven accommodates a compression coil spring and a base end portion of a linear motion rod from its front end side to prevent it from coming off, and is attached to the distal end portion of the linear motion rod. A device having a deburring head is known. And in this rotary tool, when the head part is pressed against the workpiece, the variation in the reaction force received from the workpiece is absorbed by the elastic deformation of the compression coil spring, thereby preventing the workpiece from being excessively shaved (for example, Patent Documents). 1).

JP 2000-233350 A (see FIG. 1)

  However, the conventional rotary tool described above has a problem that it is not possible to obtain an elastic force from the compression coil spring when the head portion is pressed against the back surface of the workpiece while the rotary shaft is pulled rearward. It was. For this problem, for example, a rotary tool having a configuration in which a flange is provided at the base end portion of the linear motion rod and the flange is sandwiched between two compression coil springs housed inside a cylindrical rotary shaft is known. The conventional rotary tool having such a configuration has a problem that it is difficult to reduce the size.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a rotary tool that can absorb variations in machining reaction forces in different directions received from a workpiece and can be miniaturized.

  In order to achieve the above object, a rotary tool according to the invention of claim 1 is provided with a head part for machining a workpiece on a front end part of a rotary shaft whose rear end part can be connected to a rotary drive source. The intermediate shaft portion provided at the intermediate portion in the front-rear direction of the rotating shaft and integrated with one of the front end portion or the rear end portion, and the front end portion or the rear end portion provided at the intermediate portion in the front-rear direction of the rotary shaft An intermediate cylinder part that is integrated with the other of the intermediate shaft part so as to be movable forward and backward, an outer shaft concave part that is stepped on the outer surface of the intermediate shaft part, and an inner surface of the intermediate cylinder part A variable storage chamber formed by opposing a cylindrical inner surface recess formed in a stepped shape, and a cylinder that is accommodated in the variable storage chamber and that moves relative to the axial direction of the intermediate shaft portion and the intermediate tube portion. Push between one rear end surface and the other front end surface of the inner and outer shaft recesses Characterized in place and a compressive elastic deformable compression deformation member to be fit.

  According to a second aspect of the present invention, in the rotary tool according to the first aspect of the present invention, the compression deformation member is disposed behind the concave portion on the inner surface of the cylinder in a state where an axial load is not acting between the intermediate shaft portion and the intermediate tube portion. It is characterized in that it is in an initial deformation state in which it is compressed and elastically deformed between the end surface and the front end surface or between the rear end surface and the front end surface of the outer shaft recess.

  According to a third aspect of the present invention, in the rotary tool according to the first or second aspect, the cross section of the intermediate shaft portion and the intermediate cylinder portion is circular, and the outer peripheral surface is reduced in a stepped shape at a part of the axial direction of the intermediate shaft portion. In addition to forming a concave portion on the outer surface of the shaft, the inner peripheral surface is enlarged in a stepped shape in a part of the axial direction of the intermediate cylindrical portion to form a concave portion on the inner surface of the cylinder, and the variable accommodation chamber and the compression deformation member are cylindrical. It has the characteristics in the place.

  According to a fourth aspect of the present invention, in the rotary tool according to the third aspect, the compression deformation member is directed to the compression coil spring and the rear end surface of the compression coil spring, and contacts the rear end surfaces of both the cylindrical inner surface recess and the shaft outer surface recess. It is characterized by a rear end ring that can be contacted and a front end ring that is directed to the front end face of the compression coil spring and that can contact the front end faces of both the cylindrical inner surface concave portion and the axial outer surface concave portion.

According to a fifth aspect of the present invention, in the rotary tool according to the third or fourth aspect, in the state where an axial load is not acting between the intermediate shaft portion and the intermediate cylinder portion, A front-end diameter-reduced taper portion that is held at the origin position by locking the rear end surface and front end surface of the concave portion on the outer surface of the shaft and the compression deformation member, is provided at the head portion, and is reduced in diameter toward the front end side. A tip diameter-increasing taper portion that is enlarged in diameter toward the tip side, an engagement protrusion formed on one of the inner peripheral surface of the intermediate cylindrical portion or the outer peripheral surface of the intermediate shaft portion, and the inner peripheral surface of the intermediate cylindrical portion Alternatively, it is formed in a recess on the other outer peripheral surface of the intermediate shaft portion, and engages with the engaging protrusion when the head portion is located on the rear side of the origin position, and the head portion receives the load torque received from the work and the rear of the rotating shaft. Engage the protrusion so that it moves backward while rotating with respect to the end. The retraction engagement sliding contact portion and the other of the inner peripheral surface of the intermediate tube portion or the outer peripheral surface of the head portion are recessed and engaged with the engagement protrusion when the head portion is positioned in front of the origin position. And a forward engagement sliding contact portion for guiding the engagement protrusion so as to advance while rotating with respect to the rear end portion of the rotary shaft by the load torque received from the workpiece. Have

According to a sixth aspect of the present invention, in the rotary tool according to the third or fourth aspect of the present invention, the compression deformation member is a cylindrical inner surface recess in a state where no axial load is acting between the intermediate shaft portion and the intermediate tube portion. Or, it is in an initial deformation state in which it is compressed and elastically deformed between one rear end surface and the front end surface of the concave portion on the outer surface of the shaft, and a clearance is provided between the other rear end surface and the front end surface of the concave portion on the inner surface of the cylinder or the outer surface of the shaft surface. A tip diameter-reduced taper portion that is sandwiched between and provided at the head portion and is reduced in diameter toward the tip side, a tip diameter-increasing taper portion that is provided at the head portion and is increased in diameter toward the tip side, and an intermediate cylinder portion Engagement protrusions that are formed on one of the inner peripheral surface and the outer peripheral surface of the head portion and the other of the inner peripheral surface of the intermediate tube portion and the outer peripheral surface of the intermediate shaft portion are formed in a recessed manner. Located behind the rear end position or rear end position of the movable range When engaged with the engaging projection, retraction engaging Gosuri the head portion guides the engagement protrusion to retract while rotating with respect to the rear end portion of the rotary shaft by the load torque received from the work When the head portion is disposed on the front side of the front end position of the movable range in the clearance or the front end position thereof, the contact portion and the other one of the inner peripheral surface of the intermediate tube portion or the outer peripheral surface of the intermediate shaft portion are formed to be recessed. A forward engaging sliding contact portion that engages with the engaging protrusion and guides the engaging protrusion so that the head portion moves forward with respect to the rear end portion of the rotary shaft by a load torque received from the workpiece. It has the feature in having.

  In the rotary tool according to the first aspect, the head portion can be moved back and forth with respect to the rear end portion of the rotary shaft by fitting the intermediate shaft portion and the intermediate cylinder portion of the rotary shaft. Further, the compression deformation member is accommodated in a variable accommodation chamber in which the outer-axis concave portion of the outer surface of the intermediate shaft portion and the inner-cylindrical recess portion of the inner surface of the intermediate cylinder portion are opposed to each other, and the intermediate shaft portion and the intermediate shaft portion are interposed via the compression deformation member The tube part is locked. When the reaction force in the direction in which the head part moves backward with respect to the rear end part of the rotary shaft is received, compression is performed between one front end face and the other rear end face of the outer shaft recess and the inner tube recess. When the deformable member is compressed and conversely subjected to a processing reaction force in the direction in which the head portion advances with respect to the rear end portion of the rotating shaft, the other front end surface of the concave portion on the outer surface of the shaft and the concave portion on the inner surface of the cylinder The compression deformation member is compressed between the rear end surface of one side. As described above, in the rotary tool of the present invention, the two surfaces for compressing and compressing the compression deformable member depending on whether the head portion moves forward or backward relative to the rear end portion of the rotary shaft are the front end surface of the concave portion on the off-axis surface and the inner surface of the cylinder. Switching between the rear end surface of the recess or the rear end surface of the outer shaft surface recess and the front end surface of the cylinder inner surface recess is performed, and in either case, the same compression deformation member is compressed and deformed. That is, in the rotary tool of the present invention, it is possible to absorb the variation in the processing reaction force in different directions received from the workpiece by the compression deformation of the same compression deformation member, and thereby to the conventional rotary tool having two compression coil springs. The size can be reduced compared to the above.

  In the rotary tool according to claim 2, since the compression deformation member is compressed and elastically deformed in the no-load state, when the load starts from the no-load state, a large elastic force is obtained from the compression deformation member and high rigidity is obtained. Can be demonstrated.

  The shaft outer surface recess and the cylinder inner surface recess may have a groove shape extending in the axial direction on the outer surface or the inner surface of the intermediate shaft body or the intermediate cylinder body. The cross section of the intermediate shaft portion is circular, the outer peripheral surface is stepped in a part of the axial direction of the intermediate shaft portion to form a concave portion on the outer surface of the shaft, and the inner peripheral surface is stepped on a portion of the intermediate cylindrical portion in the axial direction. The cylinder inner surface recess may be formed by expanding the diameter so as to be attached, and the variable accommodation chamber and the compression deformation member may be formed in a cylindrical shape. According to the configuration of the third aspect, it is easier to process than the case where the concave portion on the outer surface of the shaft and the concave portion on the inner surface of the cylinder are formed into a groove shape, and the variable accommodation chamber becomes large, and a large compression deformation member can be used. .

  The compression deformable member may be a cylindrical elastomer or a compression coil spring. Further, the compression deformation member may be composed only of a compression coil spring, and both end surfaces of the compression coil spring may be brought into direct contact with the rear end surface and the front end surface of the outer shaft recess and the inner tube recess. As in the rotary tool, the compression deformation member is applied to the compression coil spring, the rear end surface of the compression coil spring, and can be brought into contact with the rear end surfaces of both the inner surface recess and the outer shaft recess, and the compression coil spring. A front end ring that is directed to the front end face of the tube and can be brought into contact with the front end faces of both the cylindrical inner surface recess and the shaft outer surface recess.

  The rotary tool according to claim 5 and claim 6 includes a tip diameter-reduced taper portion and a tip diameter-expanded taper portion in the head portion. Then, when the tip diameter-reduced taper portion of the head portion is pressed against the workpiece while the rotary tool is rotated, the load torque that the head portion receives from the workpiece is formed on one and the other of the intermediate tube portion and the intermediate shaft portion. By the engagement mechanism between the engagement protrusion and the retraction engagement sliding contact portion, it is converted into a screwing propulsion axial force facing the rear end portion side of the rotary shaft, and according to the magnitude of the screwing propulsion axial force The head portion is disposed at the linear movement position. When the workpiece shape or the fixing position varies on the side where the load torque increases, the head portion further moves to the rear end portion side of the rotary shaft, thereby suppressing an increase in load torque. On the other hand, when the shape and the fixing position of the workpiece vary on the side where the load torque is reduced, the head portion is moved to the front end side of the rotary shaft by the compression deformation member, and the drop in the load torque is suppressed.

  On the other hand, when the tip diameter-expanded taper portion of the head portion is pressed against the workpiece while the rotary tool is rotated, the load torque that the head portion receives from the workpiece is formed on one and the other of the intermediate tube portion and the intermediate shaft portion. The engagement mechanism between the engagement protrusion and the forward engagement sliding contact portion is converted into a screw propulsion axial force directed to the front end portion side of the rotary shaft, and a straight line according to the magnitude of the screw propulsion axial force. The head portion is disposed at the moving position. When the workpiece shape and the fixing position vary on the side where the load torque increases, the head portion further moves to the front end side of the rotating shaft, and the increase in load torque is suppressed. On the other hand, when the shape and the fixing position of the workpiece vary on the side where the load torque is reduced, the head portion is moved to the rear end side of the rotary shaft by the compression deformation member, and the drop in the load torque is suppressed.

  As described above, according to the rotary tool of the present invention, the variation in the amount of machining with respect to the workpiece is suppressed by displacing the linear movement position of the head portion so as to suppress fluctuations in the load torque due to variations in the shape and fixed position of the workpiece. It becomes possible.

  The rotary tool according to any one of claims 1 to 4, wherein the intermediate shaft portion is allowed to move linearly relative to the intermediate tube portion and the intermediate shaft portion is rotated relative to the intermediate tube portion. You may make it the structure provided with the rotation control part which regulates. For example, a long hole is formed in one of the intermediate cylinder part or the intermediate shaft part, and a pin that is slidably engaged with the long hole is fixed to the other, and a rotation restricting part is configured by the long hole and the pin. Also good.

The side view of the rotary tool which concerns on 1st Embodiment of this invention. Side view of rotating tool Side cross-sectional view of intermediate cylinder parts Side sectional view of variable storage chamber and compression deformation member Fig. 2 is a cross-sectional view of the rotary tool taken along the line AA in Fig. 2. Side view of core shaft (A) A side sectional view of the variable accommodation chamber and the compression deformation member in a state where the intermediate shaft portion is retracted with respect to the intermediate cylinder portion, and (B) a variable accommodation chamber in which the intermediate shaft portion is advanced relative to the intermediate cylinder portion. Side sectional view of the compression deformation member, Development of the outer peripheral surface of the core shaft Side view when machining a workpiece with a taper at the tip of the head Side view when machining a workpiece with the taper at the tip of the head Side sectional view of the rotary tool according to the second embodiment of the present invention. Fig. 11 is a plan sectional view of the rotary tool taken along the line BB in Fig. 11. Side sectional view of variable accommodation chamber and compression deformation member according to Modification 1 Side sectional view of variable accommodation chamber and compression deformation member according to Modification 2

[First Embodiment]
Hereinafter, embodiments of the present invention will be described with reference to FIGS. As shown in FIG. 1, a rotary tool 10 of this embodiment has a rotary shaft 10S formed by assembling a base shaft 11 and a core shaft 20, and a head for machining a workpiece at the front end of the rotary shaft 10S. The unit 21 is provided.

  The base shaft 11 has an intermediate cylindrical portion 14 according to the present invention at the tip side from the axial intermediate portion, and the rotor connecting portion 12 at the rear end side from the intermediate portion. The intermediate cylinder part 14 and the rotor connection part 12 are both cylindrical, and the outer diameter of the intermediate cylinder part 14 is larger than that of the rotor connection part 12. In addition, a tapered surface 12T that gradually increases in diameter toward the intermediate cylinder portion 14 is formed on the outer surface of the front end portion of the rotor connecting portion 12, and the outer surface of the front end portion of the intermediate cylinder portion 14 is gradually contracted forward. A tapered portion 14T having a diameter is provided.

  As shown in FIG. 2, the base shaft 11 is formed by screwing a rear end shaft part 16 to the rear end of the intermediate cylinder part 15. As shown in FIG. 3, the intermediate cylinder part 15 is entirely cylindrical, and constitutes the whole of the intermediate cylinder part 14 of the base shaft 11 excluding the end on the tapered surface 12T side. In addition, a small diameter portion 15A, a medium diameter portion 15B, and a large diameter portion 15C are provided on the inner side of the intermediate cylindrical part 15 so that the inner diameter gradually increases in order from the front end to the rear end side. A female screw 15D is formed at the rear end of the diameter portion 15C.

  On the other hand, the rear end shaft component 16 constitutes the entire rotor connecting portion 12 and a part of the rear end portion of the intermediate cylindrical portion 14. Specifically, as shown in FIG. 4, the rear end shaft component 16 includes an insertion tube portion 13 that fits inside the large diameter portion 15 </ b> C at the front end portion. The portion 16F projects, and the rear surface of the flange portion 16F is the tapered surface 12T described above. Further, a male screw portion 16N is formed on the outer peripheral surface of the insertion tube portion 13 on the rear side from the intermediate position in the axial direction. Then, the insertion tube portion 13 of the rear end shaft component 16 is inserted into the large diameter portion 15C of the intermediate tube component 15, and the male screw portion 16N of the rear end shaft component 16 is screwed into the female screw 15D of the intermediate tube component 15. Thus, the base shaft 11 is configured by integrally fixing the intermediate cylinder part 15 and the rear end shaft part 16 so that the front end face of the flange portion 16F is in contact with the rear end face of the intermediate cylinder part 15.

  Further, the inner diameter of the insertion cylinder portion 13 in the rear end shaft part 16 is smaller than the inner diameter of the intermediate diameter part 15B in the intermediate cylinder part 15. As a result, the intermediate cylinder portion 14 is formed with a cylinder inner surface recess 51 having a structure in which the inner peripheral surface is enlarged in a stepped shape in a part of the axial direction, and the front end surface 51F of the cylinder inner surface recess 51 is formed in the middle. The rear end surface 51R of the cylindrical inner surface recess 51 is formed by the front end surface of the insertion cylindrical portion 13 of the rear end shaft component 16, while the stepped surface of the small diameter portion 15A and the middle diameter portion 15B in the cylindrical component 15 is configured. .

  As shown in FIG. 3, a pair of pin mounting holes 19, 19 are formed in a portion of the intermediate cylinder portion 14 where the small diameter portion 15 </ b> A is formed. As shown in FIG. 5, the pair of pin mounting holes 19, 19 is formed of a pair of straight lines S 2, S 2 (hereinafter referred to as “first reference line”) parallel to a straight line S 1 orthogonal to the central axis J 1 of the intermediate cylindrical portion 14. (Referred to as “S2, S2”). Further, the first reference lines S2 and S2 are slightly shifted from the position in contact with the inner surface of the intermediate cylinder part 14 toward the central axis J1 and cross the inside of the intermediate cylinder part 14, and the axial direction of each pin mounting hole 19 is The intermediate part is open in the intermediate cylinder part 14. And the engagement pins 30 and 30 are inserted in both the pin mounting holes 19 and 19, and the axial center part in these engagement pins 30 and 30 protrudes from the inner peripheral surface of the intermediate | middle cylinder part 14, and it concerns on this invention. It is an “engaging protrusion”.

  As shown in FIG. 3, a ring groove 18 </ b> M is formed on the outer peripheral surface of the intermediate cylinder portion 14 by reducing the diameter of the position including the opening of the pin mounting hole 19 in a stepped shape. The retaining pin 18 shown in FIG. 2 is attached to the ring groove 18M, so that the engagement pin 30 is prevented from coming off in the pin attachment hole 19. In addition, a pair of flat surfaces 14A and 14A for locking the spanner are formed at two positions 180 degrees apart from each other in the portion where the cylinder inner surface recess 51 is formed on the inner side of the outer peripheral surface of the intermediate cylinder portion 14, A pair of flat surfaces (not shown) similar to the above are also formed on the outer peripheral surface of the rear end shaft component 16.

  As shown in FIG. 6, the core shaft 20 includes an intermediate shaft portion 22 according to the present invention and a head portion 21 fixed to the tip of the intermediate shaft portion 22, and the intermediate shaft portion 22 is an intermediate shaft portion. A contact ring 42 is assembled to the main body 22H. Specifically, the intermediate shaft portion 22 is provided with a small diameter portion 22A, a medium diameter portion 22B, and a large diameter portion 22C so that the outer diameter gradually increases from the rear end toward the front end. A contact ring 42 is press-fitted and fixed to the small diameter portion 22A.

  As shown in FIG. 4, the outer diameter of the contact ring 42 is larger than the outer diameter of the middle diameter portion 22 </ b> B, so that the intermediate shaft portion 22 has a stepped outer peripheral surface at a part in the axial direction. A shaft outer surface recess 52 having a reduced diameter is formed, and a front end surface 52F of the shaft outer surface recess 52 is formed by a stepped surface between the large diameter portion 22C and the middle diameter portion 22B in the intermediate shaft portion 22. The rear end surface 52 </ b> R of the shaft outer surface recess 52 is constituted by the front end surface of the contact ring 42. Further, the interval between the front end surface 51F and the rear end surface 51R of the cylindrical inner surface recess 51 and the interval between the front end surface 52F and the rear end surface 52R of the outer shaft surface recess 52 are the same within a range of dimensional tolerances. And the intermediate shaft part 22 fits into the intermediate cylinder part 14, and the axial outer surface recessed part 52 and the cylinder inner surface recessed part 51 oppose, and the variable storage chamber 53 which concerns on this invention is comprised in the rotating shaft 10S. .

  A compression deformation member 54 according to the present invention is accommodated in the variable accommodation chamber 53. The compression deformation member 54 has the front end ring 41 </ b> F and the rear end ring 41 </ b> R at both ends of the compression coil spring 40. And the compression deformation member 54 is accommodated in the variable accommodation chamber 53 as follows. That is, the intermediate shaft part 22 from which the rear end shaft part 16 has been removed is passed through the intermediate shaft part 22, and the intermediate end 22B of the intermediate shaft part 22 protruding rearward from the intermediate cylinder part 15 has a front end ring 41F, The compression coil spring 40 and the rear end ring 41R are inserted in this order. Then, by pressing and fixing the contact ring 42 to the small diameter portion 22A, the cylindrical inner surface recess 51 of the intermediate shaft portion 22 on the front side of the contact ring 42 includes the front end ring 41F, the compression coil spring 40, and the rear end ring 41R. The compression deformation member 54 is attached. Further, at this time, the compression deformation member 54 is brought into a preload state in which the compression deformation member 54 is compressed and deformed by a predetermined amount from the natural length state between the front end surface 52F and the rear end surface 52R of the outer shaft recess 52. When the compression deformable member 54 is attached to the intermediate shaft part 22, the intermediate shaft part 22 is pulled back into the intermediate cylinder part 15, and the rear end shaft part 16 is coupled to the intermediate cylinder part 15. As a result, the compression deformation member 54 is accommodated in the cylindrical variable accommodation chamber 53 including the cylinder inner surface recess 51 and the shaft outer surface recess 52.

  Further, since the compression deformation member 54 is accommodated in the variable accommodation chamber 53, the inner edge portion of the front end ring 41F of the compression deformation member 54 is locked to the front end surface 52F of the shaft outer surface recess 52, while the front end The outer edge portion of the front end surface of the ring 41F is engaged with the front end surface 51F of the cylindrical inner surface recess 51, and the inner edge portion of the front end surface of the rear end ring 41R of the compression deformation member 54 is engaged with the rear end surface 52R of the shaft outer surface recess 52. On the other hand, the outer edge portion of the front end surface of the rear end ring 41R is locked to the rear end surface 51R of the cylinder inner surface recess 51. As a result, the intermediate cylinder part 14 and the intermediate shaft part 22 are locked via the compression deformation member 54, and the relative linear movement of the intermediate cylinder part 14 with respect to the intermediate shaft part 22 is restricted.

  When the intermediate shaft portion 22 is pushed rearward, as shown in FIG. 7A, the compression deformation member 54 is located between the rear end surface 51R of the cylindrical inner surface recess 51 and the front end surface 52F of the outer shaft surface recess 52. It is compressed and deformed so as to be compressed, and exerts a resilience that pushes the intermediate shaft portion 22 forward. On the other hand, when the intermediate shaft portion 22 is pulled forward, the compression deformation member 54 is located between the front end surface 51F of the cylindrical inner surface recess 51 and the rear end surface 52R of the outer shaft surface recess 52 as shown in FIG. By being compressed and deformed so as to be compressed, the elastic force of pulling back the intermediate shaft portion 22 is exhibited.

  As described above, the distance between the front end surface 51F and the rear end surface 51R of the cylindrical inner surface recess 51 and the distance between the front end surface 52F and the rear end surface 52R of the outer shaft surface recess 52 are within the range of dimensional tolerances. However, a slight backlash (clearance) may occur in the range of the dimensional tolerance, so that the intermediate cylinder portion 14 is in the middle of the backlash due to the dimensional tolerance without the compression deformation member 54 being compressed as described above. There may be a slight movement relative to the shaft 22.

  As shown in FIG. 6, at the position near the rear end of the large-diameter portion 22 </ b> C of the intermediate shaft portion 22, the forward engagement sliding contact surface 24 </ b> A corresponding to the “advance engagement sliding contact portion” of the present invention, The engagement sliding contact surface 25, which is connected to the reverse engagement sliding contact surface 24 B corresponding to the “retracting engagement sliding contact portion” of the invention, is spaced 180 degrees in the circumferential direction of the intermediate shaft portion 22. Are formed in two places. Here, the engagement slidable contact surface 25 has a symmetrical shape with respect to the reference plane P0 orthogonal to the intermediate shaft portion 22 at a predetermined position in the axial direction, and the forward engagement member is located on the rear end side from the reference plane P0. While the sliding contact surface 24A is arranged, the retraction engagement sliding contact surface 24B is arranged on the front end side from the reference surface P0.

  More specifically, the pair of engagement slidable contact surfaces 25, 25 are, for example, a pair of cutters 26, 26 shown in FIG. 6 having substantially the same outer diameter as the engagement pin 30, and the intermediate shaft portion 22. Has been processed. The cutters 26 and 26 are pressed against the intermediate shaft portion 22 from both sides at a first position P1 of the intermediate shaft portion 22 that is shifted rearward from the reference plane P0 by the distance L1, and the central axes of the cutters 26 and 26 are When the same position as the first reference lines S2 and S2 is reached with respect to the intermediate shaft portion 22, the cutters 26 and 26 are directed from the first position P1 toward the reference plane P0 with respect to the intermediate shaft portion 22. The intermediate shaft portion 22 is rotated about the central axis J1 (see FIG. 5) by the twist angle θ1 (see FIG. 8) while relatively moving linearly. In other words, the unit rotation angle Δθ (= θ1 / L1) about the central axis J1 of the intermediate shaft portion 22 every time the cutters 26 and 26 are moved linearly relative to the intermediate shaft portion 22 by a unit linear movement distance. By moving only the first position P1 to the reference plane P0. In this way, a pair of forward engagement sliding contact surfaces 24 </ b> A and 24 </ b> A are formed on the intermediate shaft portion 22. Then, the intermediate shaft portion 22 is moved while moving the cutters 26 and 26 relatively straight relative to the intermediate shaft portion 22 toward the second position P2 that is separated from the reference plane P0 by a distance L2 (= L1). It is rotated in the opposite direction by the twist angle θ1 (see FIG. 6) around the central axis J1. In this way, a pair of retracting engagement sliding contact surfaces 24 </ b> B and 24 </ b> B is formed on the intermediate shaft portion 22.

  Each engagement sliding surface 25 is engaged with each engagement pin 30 in a line contact state, and the intermediate shaft portion 22 is rotated with respect to the intermediate cylinder portion 14 while maintaining the line contact state. Can do. Further, as shown in FIG. 2, in the state where no axial load is acting between the intermediate cylinder portion 14 and the intermediate shaft portion 22, each engagement pin 30 is for advancing on each engagement sliding contact surface 25. The intermediate cylinder portion 14 and the intermediate shaft portion 22 are positioned by the compression deformation member 54 so as to be in line contact with the boundary line between the engagement sliding contact surface 24A and the reverse engagement sliding contact surface 24B. The position 21 is the origin position in the linear motion possible range. When the head portion 21 moves slightly rearward from the origin position, the engagement pin 30 engages with the retracting engagement sliding contact surface 24B, and when the head portion 21 moves slightly forward from the origin position, the engagement pin 30 is engaged. The mating pin 30 engages with the forward engagement sliding contact surface 24A.

  Even if the compression deformation member 54 is not compressed, the intermediate cylindrical portion 14 may move slightly with respect to the intermediate shaft portion 22 within the range of the backlash (clearance) due to the dimensional tolerance described above. In the description, the position where the engagement pin 30 is in line contact with the boundary line between the forward engagement slidable contact surface 24 </ b> A and the reverse engagement slidable contact surface 24 </ b> B is defined as the origin position of the head portion 21.

  Here, with the engagement pin 30 and the retraction engagement slidable contact surface 24B engaged, a torque is applied to the intermediate tube portion 14 so as to rotate the intermediate shaft portion 22 in the clockwise direction when viewed from the distal end side. Then, the above-described torque is converted into a propulsion axial force that moves the intermediate shaft portion 22 toward the rear end side of the intermediate cylindrical portion 14 by the sliding contact between the engagement pin 30 and the retraction engaging sliding contact surface 24B. On the other hand, when the engagement pin 30 and the forward engagement slidable contact surface 24A are engaged, a torque that rotates the intermediate shaft portion 22 in the clockwise direction when viewed from the distal end side is applied to the intermediate cylinder portion 14. The torque described above is converted into a propulsion axial force that moves the intermediate shaft portion 22 toward the front end side of the intermediate cylindrical portion 14 by sliding contact between the engagement pin 30 and the forward engagement sliding contact surface 24A. Further, as shown in FIG. 8, the arcuate groove-shaped stopper surfaces 24C and 24C corresponding to the outer diameter of the cutter 26 are formed at both ends of the engagement sliding contact surface 25. 25, the engaging pin 30 is locked to the stopper surfaces 24C and 24C, and the linear movement range of the intermediate shaft portion 22 with respect to the intermediate cylinder portion 14 is a distance L1 + L2 between the first position P1 and the second position P2. Limited.

  As shown in FIG. 1, the head portion 21 includes a tip diameter-reduced taper portion 21 </ b> B on the front side and a tip-end diameter tapered portion 21 </ b> A on the rear side. The tip diameter-reduced taper portion 21B has a conical shape with a diameter reduced toward the tip side of the head portion 21, while the tip diameter-rising taper portion 21A has a truncated cone shape with a diameter enlarged toward the tip side of the head portion 21. There is no. A plurality of cutting blades 21C (see FIG. 2) are provided on the outer surfaces of the tip diameter-reduced taper portion 21B and the tip diameter-expanded taper portion 21A.

  This completes the description of the configuration of the rotary tool 10 of the present embodiment. Next, the effect of this rotary tool 10 is demonstrated. In the rotary tool 10 of the present embodiment, the rotor connecting portion 12 is connected to a rotary drive source, and as shown in FIG. 9, the rotational power Tn in the counterclockwise direction when viewed from the front end side of the rotary tool 10 is supplied from the rotary drive source. It is received and rotated. Then, for example, the inclined surface of the tip diameter-reduced taper portion 21B in the head portion 21 is pressed against the tip end of the edge portion E of the workpiece W and moved along the edge portion E, so that the workpiece W is chamfered. be able to. At this time, the intermediate shaft portion 22 receives a load torque Tr opposite to the rotational power Tn and an axial force F4 that pushes the rotary tool 10 back (rotation drive source side) as a machining reaction force. The compression deformation member 54 is slightly compressed or contracted by the axial force F4 of the pushing back, or the compression deformation member 54 is not compressed in the range of play due to dimensional tolerance, and the head portion 21 is slightly rearward from the origin position. The engaging pin 30 and the retracting engagement sliding contact surface 24B are engaged with each other. The load torque Tr is converted into a propulsion axial force F3 that moves the intermediate cylinder portion 14 toward the rear end side by sliding contact between the engagement pin 30 and the reverse engagement sliding contact surface 24B. The compression deformation member 54 is further compressed by F3. The intermediate shaft portion 22 is disposed at a linear motion position where the sum of the pushing back axial force F4 and the propulsion axial force F3 and the elastic force of the compression deformation member 54 are balanced.

  Here, when the rotary tool 10 is moved along the edge portion E of the workpiece W, for example, when the shape or fixing position of the workpiece W varies on the side where the load torque Tr increases, the intermediate shaft portion 22 It moves to the rear end side of the intermediate cylinder part 14, and the rise of the load torque Tr is suppressed. On the other hand, when the load torque Tr is small and the shape and the fixing position of the workpiece W vary, the intermediate shaft portion 22 moves to the distal end side of the intermediate cylinder portion 14 due to the elastic force of the compression deformation member 54 and the load torque Tr lowering is suppressed. That is, it is possible to suppress variations in the amount of machining on the workpiece W by displacing the intermediate shaft portion 22 so as to suppress fluctuations in the load torque Tr due to variations in the shape and fixed position of the workpiece W.

  Further, as shown in FIG. 10, the same applies to the case where chamfering is performed by pressing the inclined surface of the tip enlarged taper portion 21 </ b> A of the head portion 21 against the tip of the edge portion E of the workpiece W. That is, in this case, the axial force F2 is received in the direction in which the head portion 21 is pulled from the workpiece W, and the compression deformation member 54 is slightly compressed or compressed, or the compression deformation member 54 is compressed within a range of play due to dimensional tolerance. Instead, the head portion 21 slightly moves forward from the origin position, and the engagement pin 30 and the forward engagement sliding contact surface 24A are engaged. Then, the sliding torque between the engagement pin 30 and the forward engagement sliding contact surface 24A converts the load torque Tr into a propulsion axial force F1 that moves the intermediate cylinder portion 14 toward the front end, and the propulsion axial force F1. Thus, the compression deformation member 54 is further compressed. The intermediate shaft portion 22 is disposed at a linear motion position where the sum of the axial force F2 and the propulsion axial force F1 and the elastic force of the compression deformation member 54 are balanced. As a result, similarly to the case where the tip diameter-reduced taper portion 21B is pressed against the workpiece W, the intermediate shaft portion 22 is displaced so as to suppress the variation of the load torque Tr due to variations in the shape of the workpiece W and the fixed position. It is possible to suppress variation in the processing amount with respect to W.

  By the way, in the rotary tool 10 of this embodiment, when the head 21 receives a processing reaction force (propulsion axial force F3, push-back axial force F4) in a direction in which the head portion 21 moves backward with respect to the rotor connecting portion 12, FIG. As shown in (A), the compression deformation member 54 is compressed between the front end surface 52F of the outer shaft surface recess 52 and the rear end surface 51R of the cylinder inner surface recess 51, and conversely, the head portion 21 is connected to the rotor connection portion 12. When a machining reaction force (propulsion axial force F1, tensile axial force F2) is applied in the direction of moving forward, the rear end surface 52R of the outer shaft recess 52 and the inner surface of the cylinder are shown in FIG. 7B. The compression deformation member 54 is compressed and contracted with the front end surface 51 </ b> F of the recess 51.

  As described above, in the rotary tool 10 according to the present embodiment, the two surfaces for compressing and compressing the compression deformable member 54 depending on whether the head portion 21 moves forward or backward relative to the rotor connecting portion 12 are the front end surfaces of the shaft outer surface recess 52. 52F and the rear end surface 51R of the tube inner surface recess 51, or the rear end surface 52R of the outer shaft surface recess 52 and the front end surface 51F of the tube inner surface recess 51 are switched, and in either case, the same compression deformation member 54 is compressed. Deformed. In other words, in the rotary tool 10 of the present embodiment, variations in machining reaction forces in different directions received from the workpiece W can be absorbed by the compression deformation of the same compression deformation member 54, and thus has two compression coil springs. The size can be reduced as compared with the rotary tool.

  Further, in the conventional rotary tool provided with two compression coil springs, the head portion 21 stops with respect to the rotor connection portion 12 at a neutral position where the two compression coil springs are balanced in an unloaded state. Even if both compression coil springs are preloaded, the resilience due to the preload of both compression coil springs is canceled out, and a large resilience cannot be obtained when starting to receive a load from an unloaded state. On the other hand, in the rotary tool 10 of the present embodiment, the compression deformation member 54 is between the rear end surface 51R and the front end surface 51F of the cylinder inner surface recess 51 having a constant interval or the outer surface of the shaft in an unloaded state. Since it is compressed and elastically deformed between the rear end surface 52e of the recess 52 and the front end surface 52F, a large elastic force is obtained from the compression deformation member 54 when starting to receive a load from an unloaded state, and high rigidity is exhibited. can do.

[Second Embodiment]
The rotary tool 10V of the present embodiment is shown in FIGS. 11 and 12, and the first point is that the core shaft 20V is fitted to the base shaft 11V constituting the rotary shaft 10S so that the core shaft 20V cannot rotate and can move linearly. Different from one embodiment. Specifically, as shown in FIG. 11, a long hole 61 extending in the axial direction is formed through the axially intermediate portion of the large diameter portion 22C of the intermediate cylindrical portion 22 of the core shaft 20V. As shown in FIG. 12, pin holes 62 perpendicular to the central axis are formed in the intermediate cylinder portion 14, and the engagement pins 30 </ b> V inserted into the pin holes 62 and prevented by the retaining ring 18 are retained. The rotation restricting portion 60 according to the present invention is configured to be slidably engaged with the long hole 61. Even in such a configuration, when the workpiece W is processed by the tip diameter-reduced taper portion 21B of the head portion 21, the axial force of the push-back received by the head portion 21 from the workpiece W and the tip diameter-expanded taper portion 21A of the head portion 21 are obtained. When the workpiece W is machined, the same compressive deformation member 54 is compressed and deformed for any axial force (working reaction force) of the pulling axial force that the head portion 21 receives from the workpiece W. In other words, even with the rotary tool 10V of the present embodiment, variations in machining reaction forces in different directions received from the workpiece W can be absorbed by the compression deformation of the same compression deformation member 54, thereby providing two compression coil springs. The size can be reduced as compared with the conventional rotary tool.

[Other Embodiments]
The present invention is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present invention, and various other than the following can be made without departing from the scope of the invention. It can be changed and implemented.

  (1) In the first and second embodiments, the compression deformation member 54 according to the present invention is configured by the compression coil spring 40, the front end ring 41F, and the rear end ring 41R, but is configured only by the compression coil spring 40. May be. The compression deformation member may be a cylindrical elastomer (rubber).

  (2) Further, for example, an outer surface groove extending in the axial direction is formed at a plurality of locations or one location in the circumferential direction of the outer peripheral surface of the intermediate shaft body, while an inner surface groove corresponding to the outer surface groove is formed on the inner peripheral surface of the intermediate cylinder body. The outer surface grooves and the inner surface grooves are opposed to each other to form variable accommodation chambers, and a compression deformation member such as a compression coil spring may be accommodated in each variable accommodation chamber.

  (3) In the first and second embodiments, the intermediate shaft portion 22 is provided integrally with the head portion 21, while the intermediate cylinder portion 14 is provided integrally with the rotor connection portion 12. In addition, the intermediate shaft portion may be provided integrally with the rotor connection portion, while the intermediate cylinder may be provided integrally with the head portion. In other words, the head part 21 may be provided at the tip of the rotor connecting part 12 in the rotary tool 10 shown in FIG. 1 and the intermediate shaft part 22 may be attached to the rotational drive source.

  (4) As shown in FIG. 13, the rear end surface 51 </ b> R and the front end of the compression deformation member 54, the cylinder inner surface recess 51, with no axial load acting between the intermediate shaft portion 22 and the intermediate cylinder portion 14. When the clearance C is formed between the surface 51F and the head portion 21 is disposed at the rear end position or the rear end position of the movable range within the clearance C, the engagement pin 30 is When the head portion 21 is engaged with the retraction engagement sliding surface 24B and the head portion 21 is disposed at the front end position of the movable range in the clearance C or the front end position thereof, the engagement pin 30 is moved forward. You may make it engage with the contact surface 24A. Further, in such a configuration, in order to prevent the intermediate shaft portion 22 and the intermediate cylinder portion 14 from rattling in the range of the clearance C, as shown in FIG. May be provided.

10, 10V Rotating tool 10S Rotating shaft 14 Intermediate cylinder part 15 Intermediate cylinder part 21 Head part 21A Tip enlarged taper part 21B Tip reduced taper part 22 Intermediate shaft part 24A Advance engagement sliding contact (advance engagement sliding contact) Part)
24B Retraction engagement sliding surface (retraction engagement sliding portion)
30, 30V engagement pin 40 compression coil spring 41F front end ring 41R rear end ring 51 cylindrical inner surface recess 51F front end surface 51R rear end surface 52 shaft outer surface recess 52F front end surface 52R rear end surface 53 variable accommodation chamber 54 compression deformation member 60 rotation restricting portion 61 length Hole 62 Pin hole W Workpiece

Claims (6)

In a rotary tool provided with a head portion for processing a workpiece at a front end portion of a rotary shaft that can connect a rear end portion to a rotational drive source,
An intermediate shaft portion provided in an intermediate portion in the front-rear direction of the rotating shaft and integrated with one of the front end portion or the rear end portion;
An intermediate cylinder portion provided at an intermediate portion in the front-rear direction of the rotating shaft, integrated with the other of the front end portion or the rear end portion, and fitted to the outside of the intermediate shaft portion so as to be movable back and forth;
A variable storage chamber formed by opposing a concave portion formed on the outer surface of the intermediate shaft portion in a stepped manner on the outer surface of the intermediate shaft portion and a concave portion formed on the inner surface of the intermediate tube portion so as to be depressed in a stepped manner;
Accommodated in the variable accommodation chamber, with the relative axial movement of the intermediate shaft portion and the intermediate tube portion, one rear end surface and the other front end surface of the tube inner surface recess and the shaft outer surface recess A rotary tool comprising: a compression deformation member capable of compression elastic deformation so as to be compressed between the two.   In a state where an axial load is not applied between the intermediate shaft portion and the intermediate tube portion, the compression deformation member is disposed between the rear end surface and the front end surface of the tube inner surface recess, or the shaft outer surface. The rotary tool according to claim 1, wherein the rotary tool is in an initial deformation state in which it is compressed and elastically deformed between a rear end surface and a front end surface of the recess. A cross section of the intermediate shaft portion and the intermediate cylinder portion is circular,
The outer peripheral surface is reduced in diameter in a stepped shape in a part of the intermediate shaft portion in the axial direction to form the outer shaft recess, and the inner peripheral surface is stepped in a portion of the intermediate tube portion in the axial direction The rotary tool according to claim 1 or 2, wherein the cylindrical inner surface recess is formed by expanding the diameter, and the variable accommodation chamber and the compression deformation member are formed in a cylindrical shape. The compression deformation member includes a compression coil spring,
A rear end ring that is addressed to the rear end surface of the compression coil spring and is capable of contacting both rear end surfaces of the cylindrical inner surface recess and the outer shaft surface recess;
The rotary tool according to claim 3, comprising a front end ring that is directed to a front end surface of the compression coil spring and is capable of contacting the front end surfaces of both the inner surface recess and the outer shaft recess. In a state where an axial load is not acting between the intermediate shaft portion and the intermediate cylinder portion, the head portion includes the cylindrical inner surface recess, the rear end surface and front end surface of the outer shaft surface recess, and the compression deformation member. Is held at the origin position by locking with
Provided in the head portion, a tip diameter-reduced taper portion that is diameter-reduced toward the tip side,
Provided in the head portion, a tip diameter-expanding taper portion that is diameter-expanded toward the tip side,
An engaging protrusion formed on one of the inner peripheral surface of the intermediate tube portion and the outer peripheral surface of the intermediate shaft portion;
When the head portion is located on the rear side of the origin position, the recess is formed on the other of the inner peripheral surface of the intermediate tube portion or the outer peripheral surface of the intermediate shaft portion, and the engagement protrusion is engaged. A retraction engagement sliding portion for guiding the engagement protrusion so as to retreat while rotating with respect to a rear end portion of the rotary shaft by a load torque received by the head from the workpiece;
When the head portion is formed on the other side of the inner peripheral surface of the intermediate tube portion or the outer peripheral surface of the head portion, the head portion engages with the engaging protrusion when the head portion is located in front of the origin position, and the head portion And a forward engagement sliding contact portion that guides the engagement protrusion so as to advance while rotating relative to the rear end portion of the rotary shaft by a load torque received from the workpiece. The rotary tool according to claim 3 or 4. In a state where an axial load is not acting between the intermediate shaft portion and the intermediate tube portion, the compression deformation member is formed between one rear end surface and the front end surface of the tube inner surface recess or the shaft outer surface recess. And is in an initial deformed state compressed and elastically deformed, and is sandwiched between the other rear end surface and the front end surface of the cylindrical inner surface concave portion or the outer shaft outer surface concave portion,
Provided in the head portion, a tip diameter-reduced taper portion that is diameter-reduced toward the tip side,
Provided in the head portion, a tip diameter-expanding taper portion that is diameter-expanded toward the tip side,
An engaging protrusion formed on one of the inner peripheral surface of the intermediate tube portion or the outer peripheral surface of the head portion;
When the head portion is formed on the other side of the inner peripheral surface of the intermediate tube portion or the outer peripheral surface of the intermediate shaft portion and the head portion is arranged on the rear side of the rear end position or the rear end position of the movable range in the clearance. Further, the retracting portion that engages with the engaging protrusion and guides the engaging protrusion so that the head portion moves backward with respect to the rear end portion of the rotating shaft by a load torque received from the workpiece. Engagement sliding contact portion,
When the head portion is disposed in front of the front end position of the movable range within the clearance or the front end position of the intermediate cylindrical portion is formed in the other of the inner peripheral surface of the intermediate cylindrical portion or the outer peripheral surface of the intermediate shaft portion, A forward engagement member that engages with the engagement protrusion and guides the engagement protrusion so that the head portion moves forward with respect to the rear end portion of the rotating shaft by a load torque received from the workpiece. The rotary tool according to claim 3, further comprising a sliding contact portion.

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