JP2009297858A - Wrench - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely release the bite of a sleeve to a nut after tightening. <P>SOLUTION: In this wrench 1, a spindle 21 to which a force is transmitted from the output shaft 4 of a motor 3 through a first gear 7, an inner sleeve 31 which is rotated when the spindle 21 is rotated and to which the nut is allowed to fit, and a reverse rotation operating mechanism for reversely rotating the spindle 21 after the motor 3 is stopped by the predetermined tightening torque of the inner sleeve 31 are installed in a housing 2. The first gear 7 comprises a one-way clutch 13 which allows only the normal rotation of the first gear 7 for rotating the spindle 21 in the tightening direction and which restricts the reverse rotation of the first gear 7. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wrench used for tightening a nut.

  For example, as disclosed in Patent Document 1, a wrench has a spindle coaxially arranged via a planetary gear reduction mechanism behind a sleeve fitted to a nut, and rotates the sleeve by torque transmission from the motor to the spindle. The nut can be tightened. In particular, here, a sleeve that is rotated and transmitted from the output shaft of the motor is separately provided on the spindle, and the sleeve is covered behind the sleeve so that it can rotate integrally with the spindle and slide back and forth. Through a steel ball that covers a sleeve and a transmission member straddling an inclined groove provided on one side and an axial groove provided on the other side, by sheathing a transmission member biased forward by a coil spring A reverse rotation operation mechanism is configured in which the transmission members are linked to the switch ON / OFF via a guide rod or the like.

  Therefore, when the spindle rotates and reaches a certain tightening torque, the transmission member rotates in the tightening direction by the guide of the inclined groove and moves backward against the bias of the coil spring, and the switch is turned off via the guide rod or the like. To stop the motor drive. After that, the transmission member returns to the forward position while rotating in reverse by the bias of the coil spring, and the motor is rotated in reverse via the spindle, and the spindle is rotated in reverse by the inertial force to bite the sleeve to the nut. It is designed to cancel automatically.

Japanese Patent Laid-Open No. 11-873

  In the conventional wrench described above, since the release of the bite depends on the inertia force of the reverse rotation of the motor, when the transmission member rotates reversely, the reverse rotation of the motor ends before the spindle rotates reversely. As a result, the biting of the sleeve onto the nut is not released with certainty, leading to a decrease in usability and reliability.

  Therefore, an object of the present invention is to provide a wrench that can reliably release the biting of the sleeve onto the nut after being tightened and is excellent in usability and reliability.

In order to achieve the above object, the invention according to claim 1 allows the intermediate transmission member between the output shaft of the motor and the spindle only to rotate positively of the intermediate transmission member in which the spindle rotates in the tightening direction. A one-way clutch that restricts reverse rotation of the intermediate transmission member is provided.
According to a second aspect of the present invention, in the configuration of the first aspect, in order to form the one-way clutch in a simple and space-saving manner, the one-way clutch includes a cylindrical main body that is externally mounted on a shaft portion provided in the intermediate transmission member; An engagement element provided in the inner surface of the main body and provided to be able to roll in the circumferential direction of the shaft part in a plurality of clutch grooves whose bottom surface becomes deeper as the shaft part moves in the normal rotation direction; And an urging member that urges the shaft portion in the forward rotation direction. When the shaft portion rotates in the reverse direction, the engagement member rotates in reverse against the urging force of the urging member due to friction with the shaft portion. It rolls in the direction and engages between the bottom surface of the clutch groove and the shaft portion to restrict reverse rotation of the intermediate transmission member.

According to the first aspect of the present invention, since the one-way clutch is provided on the intermediate transmission member, the reverse rotation operation is not transmitted to the output shaft side, but is reliably transmitted to the spindle. Therefore, the biting of the sleeve to the nut can be reliably released, and the usability and reliability are excellent. In particular, since the reverse rotation of the spindle is performed reliably, even if the nut size changes, it can be handled with a single wrench if the sleeve is replaced.
According to the second aspect of the invention, in addition to the effect of the first aspect, the one-way clutch can be formed easily and in a space-saving manner by using the shaft portion of the intermediate transmission member.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a partial longitudinal sectional view showing a primary tightening wrench which is an example of a wrench. A primary tightening wrench (hereinafter simply referred to as “wrench”) 1 is provided at the rear of the housing 2 (right side in FIG. The output shaft 4 is accommodated with the output shaft 4 facing upward, and an intermediate shaft 6 is supported behind the output shaft 4 in parallel with the output shaft 4, and is provided between the output shaft 4 and the intermediate shaft 6. The first gear 7 as a member is engaged with the pinion 5 of the output shaft 4 and the second gear 8 provided integrally with the intermediate shaft 6.

  In the first gear 7, the upper shaft portion 9 is pivotally supported by a ball bearing 10, while the lower surface is supported by a thrust bearing 11, and the lower shaft portion 12 is inserted into a one-way clutch 13 held in the housing 2. Has been. As shown in FIGS. 2 (A) and 2 (B), the one-way clutch 13 has an oval shape in which the cross section is formed in the circumferential direction of the shaft portion 12 on the inner periphery of the cylindrical main body 14, and the inner periphery side is A plurality of clutch grooves 15, 15... To be opened are formed at predetermined intervals, and a clutch pin 16 having a circular cross section as an engagement member is accommodated in each clutch groove 15 so as to be movable in the circumferential direction. A coil spring 19 serving as an urging member is interposed between a cradle 17 provided at one end of the clutch groove 15 and a side surface of the clutch pin 16 to urge the clutch pin 16 toward the other end side of the clutch groove 15. It is.

  Reference numerals 20 and 20 denote bearing metals which are fitted on the top and bottom of the main body 14 to close the top and bottom of the clutch groove 15 to restrict the vertical movement of the clutch pin 16 and support the shaft portion 12. Further, the bottom surface 18 of each clutch groove 15 gradually becomes shallow in the radial direction of the main body 14 as it goes from the end opposite to the cradle 17 toward the cradle 17 and becomes a minimum depth immediately before the cradle 17. It is formed in a V shape. Therefore, the clutch pin 16 gradually moves toward the center of the main body 14 as it approaches the cradle 17 against the bias of the coil spring 19.

The one-way clutch 13 causes the first gear 7 to rotate forward in the direction of the arrow in FIG. 2B when the output shaft 4 is rotated forward, so that the clutch is caused by the friction with the shaft portion 12 and the bias of the coil spring 19. The pin 16 rolls to the end side opposite to the cradle 17 in the clutch groove 15. Therefore, the clutch pin 16 rolls between the bottom surface 18 of the clutch groove 15 and the shaft portion 12, and the first gear 7 can continue to rotate normally.
On the other hand, when the output shaft 4 tries to rotate in the reverse direction, as shown in FIG. 3C, each clutch pin 16 resists the bias of the coil spring 19 due to friction with the shaft portion 12, and the cradle 17 in the clutch groove 15 It rolls to the side and engages between the bottom surface 18 of the clutch groove 15 and the shaft portion 12. Therefore, the first gear 7 is restricted from rotating in the right rotation direction in FIG.

  On the other hand, above the intermediate shaft 6, the spindle 21 whose front end is directed forward is rotatably supported by ball bearings 22 and 23, and the rotation of the intermediate shaft 6 is performed via a transmission mechanism 24 provided on the spindle 21. Can be transmitted to the spindle 21. In front of the spindle 21, a planetary gear speed reduction mechanism 25 having three stages of carriers 26 for holding the planetary gears 27, 27... At the rear surface is provided, and the planetary gears 27, 27 of the rearmost carrier 26 are connected to the spindle. The front end of the foremost carrier 26 is a cylindrical output portion 29 that is pivotally supported by the housing 2 via a ball bearing 28.

  Reference numeral 30 denotes an outer sleeve that is detachably attached to the front end of the housing 2. A cylindrical inner sleeve 31 having a nut fitting portion 32 is rotatably held therein. When the outer sleeve 30 is mounted on the housing 2, the rear end of the inner sleeve 31 is loosely inserted into the output portion 29, and the teeth 33 provided on the outer periphery of the inner sleeve 31 and the inner periphery of the output portion 29 are engaged with each other. Thus, the inner sleeve 31 is connected to the output portion 29 so as to be integrally rotatable. A reaction force receiver 34 is provided on the lower surface of the outer sleeve 30 so as to prevent the outer sleeve 30 from rotating due to a reaction force during tightening by gripping the nut during tightening.

  The transmission mechanism 24 is a front portion of the spindle 21 and is externally mounted on the front sleeve 35 by a ball bearing 37 and a needle bearing 37 so as to be rotatable separately from the spindle 21. The bevel gear 39 that meshes with the bevel gear portion 38 at the tip of the spindle 21 and the axial groove 42 provided on the inner periphery and the axial groove 43 provided on the outer periphery of the spindle 21 at the rear part of the spindle 21 are fitted. A rear sleeve 40 is externally mounted by a ball 41 so as to be rotatable integrally with the spindle 21 and movable in the axial direction. The rear sleeve 40 has a diameter larger than that of the front sleeve 35 and is superposed on a rear portion of the front sleeve 35. The rear sleeve 40 is provided on the inner periphery of the superposed portion, and is inclined with respect to the axial direction. A ball 44 provided on the outer circumference and fitted between the inclined groove 46 inclined from the axial direction can rotate together with the spindle 21 and can rotate in the circumferential direction within a range in which the ball 44 rolls on the inclined groove 46. It is connected to.

  A coil spring 47 is mounted on the spindle 21 between a spring receiving plate 48 mounted on the rear side of the spindle 21 and in front of the ball bearing 23 and the rear sleeve 40. In the state in which the rear sleeve 40 is not in the position, the rear sleeve 40 is in the front position, the ball 41 is positioned between the rear end of the groove 42 and the front end of the groove 43, and the ball 44 is It is located between the front end of the.

  On the other hand, a handle 49 is formed in the lower rear portion of the housing 2, and a switch 50 that is turned on when the switch lever 51 is pressed is provided in the handle 49, and a micro switch 52 is provided. When the micro switch 52 is turned off, the drive circuit of the motor 3 is turned off.

  Further, in front of the micro switch 52, a swing lever 54 whose rear end is positioned above the operation piece 53 of the micro switch 52 is rotatable and rotated in the right direction by the torsion spring 55 (the rear end pushes the operation piece 53). Direction). A push rod 56 is provided between the upper end of the swing lever 54 and the rear sleeve 40 so as to be movable up and down. This push rod 56 is provided at the front position of the rear sleeve 40 and is provided around the outer periphery of the rear end thereof. The push rod 56 abuts against a flange 57 having a tapered surface on the front surface. 1 is pushed downward against the urging force of the torsion spring 55, and the rear end is separated from the operating piece 53 of the microswitch 52, and the state shown in FIG. The micro switch 52, the swing lever 54, the torsion spring 55, the push rod, and the transmission mechanism 24 form a reverse rotation operation mechanism of the spindle 21.

The operation of the wrench 1 configured as described above will be described with an example of tightening a nut.
First, when a nut is fitted to the fitting portion of the inner sleeve 31 at the tip, and the switch lever 51 is pushed in to turn on the switch 50, the motor 3 is driven to rotate the output shaft 4, and the first gear 7 is rotated. Then, the second gear 8 and the intermediate shaft 6 are rotated. At this time, the one-way clutch 13 permits the rotation of the shaft portion 12 as shown in FIG.
When the rotation of the intermediate shaft 6 is transmitted to the front sleeve 35 via the bevel gear 39, it is transmitted to the rear sleeve 40 via the ball 44 and further transmitted to the spindle 21 via the ball 41 to rotate the spindle 21. The rotation of the spindle 21 is decelerated at each stage of the planetary gear reduction mechanism 25 and transmitted to the output portion 29 at the tip, and the inner sleeve 31 is rotated. Therefore, the nut held by the inner sleeve 31 is screwed.

  When the screwing of the nut proceeds and a certain torque is reached, the ball 44 moves backward while rolling the inclined groove 46, and the rear sleeve 40 together with the ball 44 moves backward against the bias of the coil spring 47, and the original rotational direction. Rotate slightly. Thereafter, when the flange 57 is removed from the upper end of the push rod 56 due to the retraction of the sleeve 40, the push rod 56 is lifted by the urging force of the torsion spring 55 as shown in FIG. Then, the oscillating lever 54 rotates to the right by the urging of the torsion spring 55, and the front end pushes down the operating piece 53 of the micro switch 52 to turn off the micro switch 52, thereby stopping the driving of the motor 3.

  When the driving of the motor 3 is stopped and the rotation of the intermediate shaft 6 and the bevel gear 39 and the front sleeve 35 is stopped, the rear sleeve 40 which has been retracted moves forward again by the bias of the coil spring 47. At this time, the ball 44 moves into the inclined groove. By moving forward 46 while rolling, it returns to the forward position while rotating slightly in the opposite direction to the reverse direction. Therefore, the spindle 21 connected to the rear sleeve 40 via the ball 41 also rotates in the same direction, and causes the inner sleeve 31 to reversely rotate via the planetary gear reduction mechanism 25. By this reverse rotation operation, the biting of the fitting portion 32 to the nut is released.

In particular, during this reverse rotation operation, the reverse rotation torque is transmitted to the front sleeve 35 via the ball 44 and also transmitted to the preceding bevel gear 39 and the intermediate shaft 6. However, the first gear 7 prevents the reverse rotation torque from being transmitted to the output shaft 4 in the free state because the one-way clutch 13 is in the position of FIG. 2C and prevents the reverse rotation of the first gear 7. Accordingly, the reverse rotational torque generated in the rear sleeve 40 is reliably transmitted to the spindle 21 and the biting of the fitting portion 32 can be reliably released.
When the reverse rotation operation is completed and the rear sleeve 40 returns to the front position, the flange 57 again contacts the upper end of the push rod 56 and pushes the push rod 56 downward, so that the swing lever 54 rotates counterclockwise, The front end is separated from the operating piece 53 of the micro switch 52 and the micro switch 52 is turned on. Therefore, the next tightening operation becomes possible.

  Thus, according to the wrench 1 of the said form, only the normal rotation of the 1st gear 7 into which the spindle 21 turns to a tightening direction is permitted to the 1st gear 7, and the reverse rotation of the 1st gear 7 is controlled. By providing the one-way clutch 13, the reverse rotation operation is not transmitted to the output shaft 4 side, but is reliably transmitted to the spindle 21. Therefore, the biting of the inner sleeve 31 to the nut can be reliably released, and the usability and reliability are excellent. In particular, since the reverse rotation operation of the spindle 21 is reliably performed, even if the nut size is changed, the outer sleeve 30 can be replaced with a single wrench 1.

  In addition, the one-way clutch 13 is provided with a cylindrical main body 14 that is externally mounted on the shaft portion 12 provided on the first gear 7, and is recessed on the inner surface of the main body 14. A clutch pin 16 provided so as to be able to roll in the circumferential direction of the shaft portion 12 in each of the plurality of clutch grooves 15 having a deeper depth, and a coil spring 19 for biasing the clutch pin 16 in the forward rotation direction of the shaft portion 12. In the reverse rotation of the shaft portion 12, the clutch pin 16 rolls in the reverse rotation direction against the bias of the coil spring 19 by friction with the shaft portion 12, and the bottom surface 18 of the clutch groove 15 and the shaft The one-way clutch 13 can be formed in a simple and space-saving manner by using the shaft portion 12 of the first gear 7 by engaging with the portion 12 to restrict the reverse rotation of the first gear 7. .

The one-way clutch is not limited to the lower side of the first gear, but may be provided on the upper side to restrict the rotation of the upper shaft portion. Moreover, you may provide not only in a 1st gear but in other intermediate transmission members, such as a 2nd gear, an intermediate shaft, and a bevel gear. Of course, since the number and types of gears and intermediate shafts that serve as intermediate transmission members can be changed as appropriate, a one-way clutch may be provided in accordance with the arrangement of the intermediate transmission members.
Further, in the structure of the one-way clutch itself, contrary to the above configuration, the urging member urges the clutch pin toward the end portion where the bottom surface of the clutch groove is shallow, and in the stopped state, the clutch pin moves to the bottom surface of the clutch groove and the shaft portion. In the forward rotation, the clutch pin resists the urging force of the urging member due to friction with the shaft portion, and the bottom surface of the clutch groove is deeper side. It is good also as a structure which cancels | releases biting and accept | permits normal rotation by rolling to (B). Of course, in addition to the above-described form using a clutch pin, a ball can be used as an engagement element, or an engagement / disengagement structure between a clutch gear and a pawl member can be selected as appropriate.

In addition, the configuration of the reverse rotation operation mechanism can also be changed as appropriate. For example, the overlapping of the front sleeve and the rear sleeve may be reversed, or a plurality of coil springs for the rear sleeve may be provided.
Further, the present invention is not limited to the primary tightening wrench, but can be applied to a final tightening shear wrench or the like.

It is a longitudinal cross-sectional view of a primary tightening wrench (before tightening). It is explanatory drawing of a one-way clutch, (A) is a longitudinal cross-section, (B) (C) shows the reverse rotation control state and the normal rotation state in an AA line cross section, respectively. It is a longitudinal cross-sectional view of a primary tightening wrench (at the time of a motor stop).

Explanation of symbols

  1 .. Primary tightening wrench, 2 .. Housing, 3 .. Motor, 4 .. Output shaft, 6 .. Intermediate shaft, 7 .. First gear, 12 .. Shaft, 13 .. One-way clutch, 14 · Body · 15 · · Clutch groove, 16 · · Clutch pin, · · · Bottom, 19 · · Coil spring, 21 · · Spindle, 24 · · Transmission mechanism, · · · planetary gear reduction mechanism, 29 · · Output portion, 30 .. Outer sleeve 31.. Inner sleeve 32.. Fitting portion 35.. Front sleeve 39. Bevel gear 40. Rear sleeve 41, 44 Ball 45 45 Long groove 46 · Inclined groove, 47 · · coil spring, 50 · · switch, 51 · · switch lever, 52 · · micro switch, 53 · · operating piece, 54 · · swing lever, 56 · · push rod.

Claims (2)

A motor, a spindle that is rotationally transmitted from the output shaft of the motor via at least one intermediate transmission member, a sleeve that rotates with the rotation of the spindle and that can be fitted with a nut, and a constant tightening of the sleeve A wrench comprising a reverse rotation operation mechanism for reversely rotating the spindle after stopping the motor by torque;
A wrench characterized in that the intermediate transmission member is provided with a one-way clutch that allows only forward rotation of the intermediate transmission member in which the spindle rotates in a tightening direction and restricts reverse rotation of the intermediate transmission member.   The one-way clutch is a cylindrical main body that is externally mounted on a shaft portion provided on the intermediate transmission member, and a plurality of clutches that are recessed in the inner surface of the main body and that the bottom surface becomes deeper in the forward rotation direction of the shaft portion. An engaging element provided in the groove so as to be able to roll in the circumferential direction of the shaft part, and an urging member for urging the engaging element in the forward rotation direction of the shaft part, During rotation, the engagement element rolls in the reverse rotation direction against the urging force of the urging member due to friction with the shaft portion, and is engaged between the bottom surface of the clutch groove and the shaft portion. The wrench according to claim 1, wherein reverse rotation of the intermediate transmission member is restricted.

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