JP4529699B2 - Rotary drive tool - Google Patents

Description

  The present invention relates to a rotary drive tool that grips and rotates a member to be rotated such as a bolt, a nut, or a rotation adjusting member.

  For example, the machining of a crank journal bearing hole of a cylinder block of a multi-cylinder engine is usually performed by attaching a tool cartridge to a bearing hole machining position of a boring line bar. FIG. 6 shows an example of the structure in the vicinity of such a tool cartridge 44. A flat portion 40a is formed at the bearing hole machining position of the line bar 40 coaxially inserted into the crank journal bearing hole, and the tool cartridge 44 is mounted. An attachment hole 40b having a stepped portion is formed on the mouth side for attachment. The tool cartridge 44 mainly includes a cartridge body 45 having a flange formed on one end side, an adjustment member 46 to which a cutting tool 46c is attached, and an adjustment nut 47, and an adjustment member in which the adjustment nut 47 is screwed into a screw portion 46a. 46 is inserted into the center hole of the cartridge body 45 from one end side so as to be slidable in the axial direction, and fixed to the tip of the adjustment member 46 protruding into the storage hole 45a formed on the other end surface of the cartridge body 45 by the mounting screw 49. The adjustment member 46 is pulled down by interposing a plurality of disc springs 48 between the washer 49a and the bottom surface of the storage hole 45a, and the adjustment nut 47 is brought into contact with one end surface of the cartridge body 45 so that the axis of the adjustment member 46 is The direction position is decided. A hexagonal hole slidably engaged with a hexagonal shaft portion 46b formed in the intermediate portion of the adjustment member 46 is formed in an intermediate portion of the central hole of the cartridge main body 45, and the rotation of the adjustment member 46 with respect to the cartridge main body 45 is prevented. If the adjustment nut 47 is rotated with respect to the cartridge main body 45 by this, the adjustment member 46 moves in the axial direction with respect to the cartridge main body 45, and the amount of projection of the cutting tool 46 c from one end surface of the cartridge main body 45 changes. In the tool cartridge 44, the cartridge main body 45 is inserted into the mounting hole 40b of the line bar 40, and the flange of the cartridge main body 45 is fastened to the mouth side step of the mounting hole 40b by the mounting plate 41 and the screw 42. It is fixed to.

  The diameter of the crank journal bearing hole formed in the cylinder block is determined by the rotation radius from the rotation center of the line bar 40 to the tip of the cutting tool 46c (hereinafter simply referred to as the rotation radius of the cutting tool 46c). Adjustment is made by rotating the nut 47 to change the amount of protrusion from the one end surface of the cartridge body 45 to the tip of the blade 46c. This adjustment is made when the cutting tool 46c is replaced, and the tip of the cutting tool 46c is gradually worn by machining, and the diameter of the crank journal bearing hole gradually decreases. Therefore, the diameter of the bearing hole can be reduced by a measuring station provided after the bearing hole machining station. When the measurement result exceeds a predetermined limit, the adjustment nut 47 is rotated by the rotary drive tool to adjust the amount of protrusion from the one end surface of the cartridge main body 45 to the tip of the blade 46c, thereby adjusting the rotation radius of the blade 46c. Thus, the diameter of the bearing hole is maintained within a predetermined tolerance.

  As shown in FIG. 6, the conventional rotary drive tool for adjusting by rotating the adjustment nut 47 is rotatably supported by a tool main body that is advanced and retracted toward the tool cartridge 44 of the line bar 40, and has a pulse. A plurality of chucks 21 are supported via pivot pins 23 so as to be openable and closable in the radial direction on a chuck holder 1 fixed to the tip of a main shaft (not shown) rotated by a motor, and an actuator (not shown). ), Each chuck 21 is opened and closed, and an adjustment nut 47 provided coaxially with the tool cartridge 44 is gripped and rotated. If the measurement result at the measurement station exceeds a predetermined limit, the control device brings the rotary drive tool closer to the tool cartridge 44, holds the adjustment nut 47 by the claw portion 21a at the tip of each chuck 21, and determines the bearing hole diameter at the measurement station. A command value corresponding to the difference between the measurement result and the target value of the bearing hole diameter is given to rotate the pulse motor to rotate the adjustment nut 47, thereby correcting the rotation radius of the blade tool 46c and processing the bearing tool processed by the blade tool 46c. The hole diameter is adjusted to a predetermined target value.

  However, in adjusting the rotation radius of the cutting tool 46c of this kind of boring tool cartridge 44, if there is a misalignment between the center axis of the main shaft and the center axis of the tool cartridge 44, each chuck is gripped when the adjusting nut 47 is gripped. Since the claw portion 21a at the tip of 21 does not simultaneously hit the outer peripheral surface of the rotated member 47, thrust in a direction orthogonal to the axis (hereinafter simply referred to as lateral thrust) is applied to the adjustment nut 47. As a result, twisting occurs due to the clearance of each part and the followability of changing the rotation radius of the cutting tool 46c with respect to the command value from the control device is deteriorated. is there. Such center misalignment of the central axis occurs due to an error in the stop angle of the line bar 40, replacement of the cartridge 44, replacement of the line bar 40, change in diameter of each part, and the like.

  As a means for dealing with such misalignment in this type of rotary drive tool, for example, there is a technique disclosed in Japanese Patent Laid-Open No. 7-107700 (Patent Document 1). In this rotary drive tool, a pair of chucks are attached to a chuck holding member fixed to a tip end portion of a main shaft rotated by a motor by a fulcrum pin, and a row of balls is arranged on the front surface of a slide member provided on the main shaft so as to be movable in the axial direction. The idle rotation member is provided so as to be able to rotate and move in a direction perpendicular to the axis, and the taper surface on the front side of the idle rotation member is brought into contact with the taper surface on the rear part of each chuck. In this rotary drive tool, when the slide member and the idle rotation member provided on the front side of the slide member are moved forward by the air cylinder, the taper surface on the front side of the idle rotation member pushes the taper surface on the rear part of each chuck. Open, the claw at the tip of the chuck closes and grips the knob which is the rotated member. In this state, the main shaft is rotated by the motor to rotate the rotated member.

In the rotary drive tool disclosed in Patent Document 1, if there is a misalignment between the main shaft to which the chuck holding member is fixed and the knob that is the rotated member, the claw at the tip of one chuck first hits the knob. Since the rotating member moves in the direction perpendicular to the axis, the claw part at the tip of the other chuck hits the knob, and after each claw part at the tip of both chucks hits the knob, both the claw parts grip the knob with equal force. No lateral thrust is applied to the knob which is the rotated member. Therefore, if such a technique is applied to a rotary drive tool that rotates the adjusting nut 47 that adjusts the rotation radius of the cutting tool 46c of the tool cartridge 44 of the boring line bar 40 described above, the cutting tool for the command value due to the twist caused by the lateral thrust. Since the followability of the change of the rotation radius of 46c does not deteriorate, there is no possibility that the bearing hole diameter to be machined is distorted due to such a cause and machining defects increase.
JP-A-7-107700 (paragraphs [0022] to [0027], [0029], [0030], FIGS. 1 and 2).

  However, in the rotary drive tool disclosed in Patent Document 1 described above, when there is a misalignment between the chuck holding member fixed to the main shaft and the rotated member, an action for preventing lateral thrust from being applied to the rotated member. Since the idle rotation member moves in a direction perpendicular to the axis of the chuck holding member, the plurality of chucks supported by the chuck holding member by the fulcrum pins are center lines (in the case of a pair of chucks). The rotated member is gripped in a state in which the bisectors) are inclined with respect to the central axis of the main shaft. For this reason, when rotating the rotated member, a force is applied to shave the central axis, and this is used to rotate the adjusting nut 47 that adjusts the rotational radius of the cutting tool 46c of the tool cartridge 44 for boring. If this is the case, the tool cartridge 44 will still be twisted even if there is a difference in degree, the followability of the change of the rotation radius of the cutting tool 46c with respect to the command value will be lowered, the bearing hole diameter to be machined will be distorted and machining defects will increase. There is a risk. Therefore, the technique of Patent Document 1 is not sufficient to prevent an increase in processing defects due to twisting. The problem caused by the twisting of the rotated member by this type of rotary drive tool is not limited to rotating the adjusting nut for adjusting the turning radius of the cutting tool of the tool cartridge for boring, but various rotating adjusting members, bolts, nuts, etc. It also occurs when the rotated member is gripped and rotated.

  The present invention solves such problems, and even if there is a misalignment between the main shaft of the rotary drive tool and the rotated member, the rotary drive can rotate the rotated member without causing twisting. The purpose is to provide a tool.

To this end, the rotary drive tool according to the present invention supports a plurality of chucks so that they can be opened and closed in a radial direction, respectively, on a chuck holder provided at the tip of a main shaft that is rotatably supported by a tool body and rotated by a motor. Each chuck is opened and closed by an operating member that is coaxially provided in the main shaft and is reciprocated by an actuator and attached to the tip of the operating rod. In the rotary drive tool to be driven, the chuck holder is supported by the tip of the main shaft so as to be movable in a direction perpendicular to the axis of the main shaft, and rotates between two rotating members whose rotational axes are parallel to each other. It is connected to the main shaft via a misalignment torque transmission mechanism that transmits Is axially coupled to allow movement in a direction perpendicular to its axis at the distal end of the actuating rod together is fitted and supported in a freely axially slidable, core difference torque transmitting mechanism, the distal end surface of the main shaft and which A pair of slidably interposed between the chuck holder and the rear end surface of the base of the chuck holder opposed to each other, and two pairs extending outwardly along two diametrical directions intersecting each other and a central hole through which the operating rod is inserted with a gap And a pair of first connecting pins that are slidably engaged with a pair of guide grooves that protrude from the front end surface of the main shaft and extend along one diametrical direction. And a pair of second connecting pins that are slidably engaged with a pair of guide grooves protruding from the rear end surface of the chuck holder and extending along the other diameter direction .

2. The rotary drive tool according to claim 1 , wherein the first and second connecting pins are slidably engaged with the guide grooves via sliders that are slidably engaged with the guide grooves. preferable.

The rotary drive tool according to claim 1 or 2 , wherein the holding cylinder fixed to the outer peripheral surface of the front end portion of the main shaft is formed with an inward flange portion at the front end portion protruding in the axial direction from the front end surface, and the chuck holder The outer edge protruding outward from the base is positioned between the front end surface of the main shaft and the inner end surface of the inward flange portion, and between the outer edge portion facing each other and the inner end surface of the inward flange portion. A plurality of balls held by a torque transmission plate are interposed between the front end surface of the main shaft and the rear end surface of the base that face each other with a thrust bearing interposed therebetween, and the main shaft is orthogonal to the main shaft axis. It is preferable to support it so that it can move in the direction of movement.

According to the rotary drive tool of the present invention, the chuck holder is supported at the tip of the main shaft so as to be movable in a direction orthogonal to the axis of the main shaft, and the rotation axes are different from each other in parallel. It is connected to the main shaft through a misalignment torque transmission mechanism that transmits rotation between the two rotating members, and the operating member is coaxially and slidably fitted and supported in the chuck holder while operating rod. Is connected to the front end of the chuck so as to allow movement in a direction perpendicular to the axis thereof, so that even if the center axis of the main shaft and the center axis of the rotated member are misaligned, the claw portion of each chuck is rotated. By gripping the member, the chuck holder and the rotated member are automatically aligned, and the chuck holder moves in parallel with the main shaft. Centerline without tilting, is coincident with the axis of the adjusting nut. Accordingly, each claw portion grips the rotated member with an equal force and transmits only the torque to the rotated member to rotate, so that the rotated member is a command value given to the motor that drives the main shaft from the control device. Depending on the rotation, it can be rotated without any twisting. Further, the misalignment torque transmission mechanism includes a center hole through which an operating rod is inserted with a gap between the front end surface of the main shaft and the rear end surface of the base portion of the chuck holder facing the main shaft. A torque transmission plate formed with two pairs of guide grooves extending outward along two diametrical directions intersecting each other, and a pair of guide grooves protruding from one end surface of the main shaft and extending along one diametrical direction A pair of first coupling pins that are slidably engaged with each other, and a pair of slidably engaged with a pair of guide grooves that protrude from the rear end surface of the chuck holder and extend along the other diameter direction. The center connecting torque transmission mechanism has a substantially constant thickness and is arranged between the main shaft and the base of the chuck holder so that there is no gap between them. The whole tool and Te can be combined into a compact, also can reduce the manufacturing cost.

According to the invention of claim 2 , the first and second connecting pins are slidably engaged with the respective guide grooves via sliders that are slidably engaged with the respective guide grooves. Since the area of the sliding portion of the mechanism increases, the durability of the misalignment torque transmission mechanism can be improved, and as a result, the durability of the rotary drive tool can be improved.

The holding cylinder fixed to the outer peripheral surface of the front end portion of the main shaft has an inward flange portion at the front end portion that protrudes in the axial direction from the front end surface, and the chuck holder has an outer edge portion that protrudes outward from the base portion of the main shaft. Between the front end surface of the main shaft and the inner end surface of the inward flange portion, a thrust bearing is interposed between the outer edge portion facing each other and the inner end surface of the inward flange portion, and the front end surface of the main shaft facing each other 4. The invention according to claim 3 , wherein a plurality of balls held by a torque transmission plate are interposed between the rear end surfaces of the base portion, and supported at the front end portion of the main shaft so as to be movable in a direction perpendicular to the axis of the main shaft. For example, the chuck holder has a thrust bearing and a torque between the front end surface of the main shaft and the inner end surface of the inward flange portion formed at the front end portion of the holding cylinder fixed to the main shaft. Because it is held via a plurality of balls held by Itaruban, movement in a direction perpendicular to the axis relative to the main shaft becomes lighter. Therefore, the chuck holder and the rotated member are aligned with very little force when each chuck claw grips the rotated member, and the force with which each claw grips the rotated member becomes even more uniform. Become.

  The best mode for carrying out the rotary drive tool according to the present invention will be described below with reference to FIGS. The rotary drive tool of this embodiment adjusts the radius of rotation of the cutting tool 46c of the tool cartridge 44 provided in the boring line bar 40 for machining the crank journal bearing hole of the cylinder block as described with reference to FIG. Used to rotate the adjustment nut 47, the tool main body 10, the main shaft 11 rotatably supported by the tool main body 10 and rotated by the motor 35, and the front end of the main shaft 11 orthogonal to the axis A chuck holder 20 that is supported so as to be movable in parallel, a misalignment torque transmission mechanism A that is provided between the main shaft 11 and the chuck holder 20 and transmits the former rotation to the latter, and is pivotally supported by the chuck holder 20. A plurality of chucks 21 supported so as to be openable and closable in the radial direction via pins 23 and coaxial in the main shaft 11 The actuating member 32 which is attached to the distal end of the rod 30 is reciprocated open and close the chucks 21 provided it is an main configuration.

  As shown in FIG. 1, a main shaft 11 is rotatably supported on a tool body 10 provided to be able to approach and separate from a tool cartridge 44 provided on a line bar 40 via composite bearings 12a and 12b. . A sleeve 11b having a flange is inserted halfway into a cylindrical hole 11a having a bottom that is coaxially formed from the front end side having a large diameter of the main shaft 11, and is fixed by a bolt 11c. Part of. An operating rod 30 is fitted and supported on the inner surface of the sleeve 11b so as to be rotatable and slidable in the axial direction, and a piston 31 fixed to a boundary portion between the operating rod 30 and a rear half portion 30a formed to be slightly smaller in diameter is provided as a sleeve. The actuator is fitted into the inner surface of a cylinder chamber 31a formed between the tip of 11b and the bottom surface of the cylindrical hole 11a, and constitutes an actuator that reciprocates the operating rod 30.

  The holding cylinder 13 fixed to the outer peripheral surface of the distal end portion of the main shaft 11 by a push screw 13 b has an inward flange portion 13 a formed at the distal end portion protruding in the axial direction from the distal end surface of the main shaft 11. The main shaft 11 has a pulse motor (motor) provided in the tool body 10 via a gear train including a gear 39 and gears 36, 37, and 38 coaxially fixed to the rear portion thereof by a key 39a and a ring nut 39b. 35 is rotationally driven.

  As shown in FIGS. 1 to 3, the chuck holder 20 is composed of a holder main body 20a and a base portion 20b that are centered by a central joint and are coaxially connected integrally by a bolt 20e. A continuous center hole 20d is formed. The chuck holder 20 has an outer edge portion 20f protruding outward from the base portion 20b between the front end surface of the main shaft 11 and the inner end surface of the inward flange portion 13a, and is inwardly facing the outer edge portion 20f facing each other. A thrust bearing 19 composed of a large number of balls 19b and a retainer 19a that holds the balls 19b is interposed between the inner end surface of the flange portion 13a, and between a front end surface of the main shaft 11 and a rear end surface of the base portion 20b facing each other. The ball 14 held by the torque transmission plate 15 of the misalignment torque transmission mechanism A is interposed between the center hole 20d and the outer peripheral surface of the operating rod 30, and the inner peripheral surface and the outer edge portion 20f of the inward flange portion 13a. By providing a gap between the outer peripheral surfaces of the base portion 20b excluding the axis, the tip of the main shaft 11 is orthogonal to the axis thereof It is movably supported some distance parallel to. A soft seal 13c is provided between the inner peripheral surface of the inward flange portion 13a of the holding cylinder 13 and the outer peripheral surface of the base portion 20b to allow relative movement in a direction orthogonal to the axis.

  As shown in FIGS. 1, 4 and 5, the holder body 20a is formed with three holding grooves 20c extending radially outward from the center hole 20d at intervals of 120 degrees except for a part on the base 20b side. In each holding groove 20c, an intermediate portion of the chuck 21 is supported by a pivot pin 23 so that it can be opened and closed in the radial direction. Each chuck 21 integrally fixes a slide member 22 having two chamfered portions 22a on both sides of the inclined tip portion on the inner side of the end portion on the base portion 20b side, and the tip portion on the opposite side to this. A pair of claw portions 21 a arranged in a wide angle V shape (see FIG. 5) for gripping the adjustment nut (rotated member) 47 is formed inside. Each of the three chucks 21 has a portion to which each slide member 22 is attached by means of a garter spring 25 in which an elongated coil spring hung on a recess 21b formed on the outer surface on the base 20b side of the pivot pin 23 is connected in an annular shape. It is elastically biased in the direction. The chucks 21 and the garter springs 25 excluding the tip portions where the claw portions 21a are formed are covered with a cylindrical cover 24 that is placed on the outer periphery of the chuck holder 20 and fixed by screws 24a.

  The operating member 32 fitted and supported in the center hole 20d located in the holder main body 20a so as to be slidable in the axial direction slides 22 fixed to the end of each chuck 21 at intervals of 120 degrees along the outer periphery. Three inclined grooves 32a that are slidably engaged with the inclined two chamfered portions 22a are formed, and the tips of the two chamfered portions 22a are brought into contact with the bottom surfaces of the inclined grooves 32a by garter springs 25. ing. A semicircular circular groove 32c is formed in the small diameter portion 32b protruding rearward from the operating member 32, and a holding hole 30b is formed coaxially at the tip of the operating rod 30, and this holding is performed. A pair of locking holes 32d parallel to each other are formed on both sides of the hole 30b. The operating member 32 has a small-diameter portion 32b inserted into the holding hole 30b so as to be in contact with the distal end surface of the operating rod 30, and a pair of engaging pins 33 fitted into the respective locking holes 32d are formed into annular grooves. By engaging with 32c, it is rotatably connected to the tip of the operating rod 30. Between the inner surface of the holding hole 30b and the outer surface of the small-diameter portion 32b, and between the inner method of both the engaging pins 33 and the valley bottom of the annular groove 32c, the central hole 20d of the base portion 20b and the outer peripheral surface of the operating rod 30 described above. As a result, the actuating member 32 can be moved a certain distance in the direction perpendicular to the axis of the actuating rod 30. When the actuating rod 30 is reciprocated by the actuator 31, the actuating member 32 reciprocated together with this reciprocates each slide member 22 abutted on the inclined groove 32 a in the radial direction, thereby leading the tip of each chuck 21. The claw portion 21a is opened and closed.

  Next, the misalignment torque transmission mechanism A that transmits the rotation of the main shaft 11 to the chuck holder 20 will be described with reference to FIGS. 1 and 2. The torque transmission plate 15 slidably interposed between the front end surface of the main shaft 11 and the rear end surface of the base 20b of the chuck holder 20 facing the main shaft 11 is a center through which the operating rod 30 is inserted with a gap. Holes 15c are formed, and there are two pairs of guide grooves 15a that move a little in the direction orthogonal to the axis with respect to the main shaft 11 and the operating rod 30, and extend outward along two diametrical directions orthogonal to each other. Is formed. A slider 16 is slidably engaged with each guide groove 15a along the radial direction, and is slidably engaged with a pair of guide grooves 15a extending along one diameter direction. A pair of first connecting pins 17a, which are arranged symmetrically with respect to the rotation axis and project from the front end surface of the sleeve 11b of the main shaft 11, are rotatably fitted in the holes formed at the centers of the pair of sliders 16. The holes formed at the centers of the pair of sliders 16 inserted and slidably engaged with the pair of guide grooves 15a extending along the other diametrical direction are arranged symmetrically with respect to the rotation axis. A pair of second connection pins 17b protruding from the rear end surface of the base 20b of the chuck holder 20 are rotatably fitted and inserted. As described above, the misalignment torque transmission mechanism A that transmits the rotation between the two rotating members whose rotational axes are shifted in parallel with each other is configured.

  The amount and direction of misalignment between the rotation axis of the main shaft 11 and the chuck holder 20 to which the rotation is transmitted by the misalignment torque transmission mechanism A is between the center hole 20d and the outer peripheral surface of the operating rod 30 described above. The chuck holder 20 is optional within an allowable range in which the chuck holder 20 can move in a direction perpendicular to the axis with respect to the main shaft 11 by a gap such as. The allowable range of the misalignment amount is set to a value larger than the expected maximum misalignment between the main shaft 11 and the tool cartridge 44, and is 0.3 mm in this embodiment.

  The rotary drive tool of this embodiment is provided in the crank journal bearing hole machining station of the cylinder block, and adjusts the turning radius of the cutting tool 46c of the tool cartridge 44 provided in the boring line bar 40 as described with reference to FIG. It is used to do. In the inoperative state, the piston 31 retracts the operating rod 30 and the claw portion 21a at the tip of the chuck 21 is opened. A control device (not shown) for controlling the operation of the rotary drive tool moves the tool body 10 if the measurement result of the bearing hole diameter measured at the measurement station provided after the bearing hole machining station exceeds a predetermined limit. The position of the claw portion 21a at the tip of each chuck 21 is located outside the adjustment nut 47 of the tool cartridge 44, and the operating rod 30 is advanced by the piston 31 to close the claw portion 21a at the tip of each chuck 21 and coaxial with the tool cartridge 44. The adjustment nut 47 provided in the is gripped. If there is a misalignment between the chuck holder 20 and the adjustment nut 47 at the time of gripping, the claw portion 21a at the tip of one chuck 21 first comes into contact with the outer surface of the adjustment nut 47, but the center between the main shaft 11 and the tool cartridge 44. If the deviation is within the allowable range described above, the claw portion 21a at the tip of the chuck 21 remaining after the chuck holder 20 is translated in the direction perpendicular to the axis hits the outer surface of the adjustment nut 47, and the claw portion 21a of each chuck 21 is adjusted. After hitting the nut 47, each claw portion 21a holds the adjusting nut 47 with an equal force. As a result, the chuck holder 20 and the adjustment nut 47 are automatically aligned, and the chuck holder 20 moves in parallel with the main shaft 11. Therefore, the center lines of the three chucks 21 are not inclined and the adjustment nut 47 Matches the axis.

  After the adjustment nut 47 is gripped by the claw portion 21a at the tip of each chuck 21 in this way, the control device sends a command value corresponding to the difference between the measurement result of the bearing hole diameter at the measurement station and the target value of the bearing hole diameter to the pulse motor 35. Then, the main shaft 11 is rotated through the gear trains 36 to 39, the chuck holder 20 is rotated through the misalignment torque transmission mechanism A, and the adjustment nut 47 is rotated, thereby correcting the rotation radius of the cutting tool 46c. Then, the diameter of the bearing hole processed by the cutting tool 46c is adjusted to be a predetermined target value.

  According to the above-described embodiment, each claw portion 21a grips the adjusting nut 47 with an equal force, and the chuck holder 20 moves parallel to the main shaft 11 so that the center lines of the three chucks 21 are not inclined. Since the adjustment nut 47 is rotated by the chuck holder 20 in a state where it coincides with the axis of the adjustment nut 47, the adjustment nut 47 is rotated without difficulty by the claw portions 21a without causing twisting. Accordingly, the followability of the change in the radius of rotation of the cutting tool 46c with respect to the command value from the control device does not deteriorate, so there is no possibility that the bearing hole diameter to be machined will be distorted due to such a cause and the machining defect will increase.

  In the above-described embodiment, the misalignment torque transmission mechanism A is slidably interposed between the front end surface of the main shaft 11 and the rear end surface of the base 20b of the chuck holder 20 facing the main shaft 11, and the operating rod 30 is a gap. A torque transmission plate 15 formed with a center hole 15c inserted therethrough and two pairs of guide grooves 15a extending outwardly along two diametrical directions intersecting each other, and projecting from the front end surface of the main shaft 11. A pair of first connecting pins 17a slidably engaged with a pair of guide grooves 15a extending along one diametrical direction, and protruding from the rear end surface of the chuck holder 20 along the other diametrical direction. The pair of second connecting pins 17b are slidably engaged with the extending pair of guide grooves 15a. In this way, the misalignment torque transmission mechanism A has a substantially constant thickness. Simple Becomes ones, since it is arranged without a gap between the base portion 20b of the main shaft 11 and the chuck holder 20, can be combined into compact rotary driving tool as a whole, also I can reduce the manufacturing cost.

  In the above-described embodiment, the guide groove 15a of the torque transmission plate 15 has a U-shape that is opened outward in the radial direction over the entire width in the thickness direction. In this way, torque can be transmitted in the entire width in the thickness direction. Thus, the thickness of the torque transmission plate 15 can be reduced to reduce the misalignment torque transmission mechanism A. However, the present invention is not limited to this, and guide grooves 15a connected to the main shaft 11 side and the chuck holder 20 side are formed on the main shaft 11 side and the chuck holder 20 side of the torque transmission plate 15, respectively. It is also possible to implement. It is also possible to carry out such that each guide groove 15a is not opened outward in the radial direction. In this embodiment, the directions of the two pairs of guide grooves 15a are orthogonal to each other, but the crossing angle of the grooves is not necessarily a right angle.

  In the embodiment described above, each chuck 21 is supported by the pivot pin 23 with respect to the chuck holder 20, but each chuck 21 may be supported by the chuck holder 20 so as to be slidable in the radial direction. The number of chucks 21 is not limited to three, and may be two or four or more.

  In the above-described embodiment, the first and second connecting pins 17a and 17b are slidably engaged with the respective guide grooves 15a via the sliders 16 that are slidably engaged with the respective guide grooves 15a. In this way, since the area of the sliding portion of the misalignment torque transmission mechanism A is increased, the durability of the misalignment torque transmission mechanism A can be improved, and as a result, the durability of the rotary drive tool can be improved. However, the present invention is not limited to this, and each of the connecting pins 17a and 17b may be engaged with the torque transmission plate 15 via a roller that is in rolling contact with each guide groove 15a. Thus, the durability of the misalignment torque transmission mechanism A and the rotary drive tool is relatively high, and the loss of transmission torque due to the frictional resistance of the misalignment torque transmission mechanism A can be reduced.

  Further, in the above-described embodiment, the chuck holder 20 has the inner edge surface of the inward flange portion 13a of the holding cylinder 13 in which the outer edge portion 20f protruding outward from the base portion 20b is fixed to the front end surface of the main shaft 11 and the main shaft 11. The thrust bearing 19 is interposed between the outer edge portion 20f facing each other and the inner end surface of the inward flange portion 13a, and between the front end surface of the main shaft 11 and the rear end surface of the base portion 20b facing each other. A plurality of balls 14 held by the torque transmission plate 15 are interposed between the front end of the main shaft 11 so as to be movable in a direction perpendicular to the axis of the main shaft 11. The chuck holder 20 has an inward flange portion formed at the front end surface of the main shaft 11 and the front end portion of the holding cylinder 13 fixed thereto. 3a is held between the ball 19b of the thrust bearing 19 and a plurality of balls 14 held by the torque transmission plate 15, so that the movement in the direction perpendicular to the axis with respect to the main shaft 11 becomes light. . Therefore, the chuck holder 20 and the rotated member 47 are aligned with very little force when the claw portion 21 a of each chuck 21 holds the rotated member 47, so that each claw portion 21 a holds the rotated member 47. The force to perform becomes even more uniform. However, the present invention is not limited to this, and the ball 14 is omitted, and the torque transmission plate 15 is slidably interposed between the front end surface of the main shaft 11 and the base portion 20 b of the chuck holder 20. It is also possible to carry out such that the base portion 20b and the inward flange portion 13a of the holding cylinder 13 are slidably brought into contact with each other.

  In the embodiment described above, the rotary drive tool used to rotate the adjusting nut 47 that adjusts the rotational radius of the cutting tool 46c of the tool cartridge 44 provided in the boring line bar 40 for machining the bearing hole has been described. The present invention is not limited to this, and may be applied to a rotary drive tool that rotates an adjusting nut 47 that adjusts the rotational radius of a blade 46c of a tool cartridge 44 provided in a boring quill other than that for processing a bearing hole. Further, the present invention can be applied to a rotary drive tool that holds and rotates various types of rotation adjusting members or rotating members such as bolts and nuts.

It is a longitudinal cross-sectional view which shows the whole structure of one Embodiment of the rotary drive tool by this invention. It is 2-2 sectional drawing of FIG. FIG. 3 is a 3-3 cross-sectional view of FIG. 1. FIG. 4 is a sectional view taken along the line 4-4 in FIG. 1. FIG. 5 is a five-view diagram of FIG. 1. It is the side view which cut the principal part of the tool cartridge by which an adjustment nut is rotated by this kind of rotational drive tool, and a blade edge position is adjusted, and the line bar which attaches it.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Tool main body, 11 ... Main shaft, 13 ... Holding cylinder, 13a ... Inward flange part, 14 ... Ball, 15 ... Torque transmission board, 15a ... Guide groove, 15c ... Center hole, 16 ... Slider, 17a ... 1st Connection pin, 17b ... second connection pin, 19 ... thrust bearing, 20 ... chuck holder, 20b ... base, 20f ... outer edge part, 21 ... chuck, 21a ... claw part, 30 ... acting rod, 31 ... actuator (piston), 32 ... Actuating member, 35 ... Motor (pulse motor), 47 ... Rotated member (adjustment nut), A ... Misaligned torque transmission mechanism.

Claims (3)

A plurality of chucks are supported by a chuck holder provided at the tip of a main shaft that is rotatably supported by a tool body and rotated by a motor so that the chuck can be opened and closed in a radial direction, and is provided coaxially within the main shaft. In the rotary drive tool that opens and closes each chuck by an operating member attached to the tip of an operating rod reciprocated by an actuator, and grips and rotates the rotated member by the claw portion of each chuck,
The chuck holder is supported at the front end of the main shaft so as to be movable in a direction perpendicular to the axis of the main shaft, and a core for transmitting rotation between two rotating members whose rotational axes are parallel to each other. It is connected to the main shaft via a differential torque transmission mechanism, and the operating member is fitted and supported coaxially in the chuck holder so as to be slidable in the axial direction and orthogonal to the axis of the tip of the operating rod. Connected to allow movement in the direction to
The misalignment torque transmission mechanism is slidably interposed between a front end surface of the main shaft and a rear end surface of the base of the chuck holder facing the main shaft, and the operation rod is inserted through a gap. A pair of torque transmission plates formed with holes and two pairs of guide grooves extending outward along two diametrical directions intersecting each other, and a pair extending along one diametrical direction protruding from the front end surface of the main shaft A pair of first connecting pins slidably engaged with the guide grooves, and a pair of guide grooves protruding from the rear end surface of the chuck holder and extending along the other diametrical direction. A rotary drive tool comprising a pair of second connecting pins to be engaged . 2. The rotary drive tool according to claim 1 , wherein the first and second connecting pins are slidably engaged with the guide grooves via sliders that are slidably engaged with the guide grooves. A rotary drive tool characterized by comprising: The rotary drive tool according to claim 1 or 2 , wherein the holding cylinder fixed to the outer peripheral surface of the front end portion of the main shaft is formed with an inward flange portion at a front end portion protruding in the axial direction from the front end surface, The chuck holder has an outer edge portion projecting outward from a base portion thereof between the front end surface of the main shaft and an inner end surface of the inward flange portion, and the outer edge portion and the inward flange portion facing each other. A thrust bearing is interposed between the inner end surface and a plurality of balls held by the torque transmission plate between the front end surface of the main shaft and the rear end surface of the base portion facing each other. A rotary drive tool characterized in that it is supported at the tip so as to be movable in a direction perpendicular to the axis of the main shaft.

Images