JPH0731281U - Buffer mechanism for electric oil pulse rotary tool - Google Patents

Abstract

(57) [Summary] [Purpose] The impact force of the oil pulse generator is buffered and the influence on the internal mechanism is eliminated. [Structure] An internal gear 13 is externally mounted on a planetary gear 9 of a reduction mechanism 6, and the internal gear 13 is rotatably supported by a ball bearing 14. A slide member 15 is arranged on the motor 4 side of the internal gear 13 so as to be slidable back and forth, and the two springs 1
7 and 17, the internal gear 13 is normally urged to rotate by the pressing force, and the planetary gear 9 revolves in the internal gear 13 by the rotation of the motor 4. It will be done.
Further, on the rear end surface of the internal gear 13, cam grooves 18, 18 ... Are formed uniformly in three directions together with tapered surfaces 18a, 18a .. Fitting recess 1 at a position corresponding to 18
. Are recessed, and steel balls 20, 20 ... Are fitted in the fitting recesses 19, respectively.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotary tool using an oil pulse generator such as an electric impulse driver or an electric impulse wrench, and more particularly to a shock absorbing mechanism for mitigating an impact generated by the rotary tool during use in the tool. .

[0002]

[Prior art]

 In the conventional electric oil pulse rotary tool (hereinafter referred to as rotary tool), as disclosed in, for example, Japanese Patent Laid-Open No. 59-129675, a motor and a planetary gear to which a rotational force is transmitted from the motor are housed in a housing. It has a speed reduction mechanism with an internal gear that is external to the speed reduction mechanism, and an oil pulse generator that is connected to the speed reduction mechanism. The pulse generator generates a momentary impact force due to hydraulic pressure, and intermittently gives a strong tightening force to the output shaft of the oil pulse generator.

[0003]

[Problems to be solved by the device]

 In the above conventional rotary tool, the motor and deceleration mechanism that rotate at a constant speed are directly connected to the oil pulse generator that instantly gives a strong rotation, so the impact force of the oil pulse generator is directly Since it bounces off to the speed reduction mechanism and the motor side, the load on the gear is increased, wear is significant, and the motor may be burned, resulting in shortening the tool life.

[0004]

[Means for Solving the Problems]

 Therefore, the present invention provides a shock absorbing mechanism for an electric oil pulse rotary tool that reduces the impact force of the oil pulse generator and suppresses the influence on the speed reduction mechanism and the motor. A pressing member that rotatably supports the internal gear and that presses the internal gear by the biasing means is provided, and the pressing force of the biasing means is at least necessary for the planetary gear of the reduction mechanism to revolve. It is set equal to the fixed force of.

[0005]

[Action]

 In normal motor rotation, the internal gear is fixed by the pressing member, and gives the planetary gear of the reduction mechanism an orbital motion to rotate the oil pulse generator. If the load on the bit side increases with tightening and the oil pulse generator generates an oil pulse, a load exceeding the fixing force of the pressing member will be applied to the internal gear, but at this time the internal gear It rotates and absorbs the shock, and the shock is not transmitted to the reduction mechanism or motor.

[0006]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 is a main body of an electric impulse driver to which the present invention is applied. Rotational force from a rear motor 4 is transmitted from a motor shaft 4a and a pinion gear 5 to an impulse motor 7 through a speed reduction mechanism 6, and together with the impulse motor 7, a bit is transmitted. The output shaft 8 on which is mounted is rotated. Further, a handle 2 in which a rechargeable battery (not shown) is detachably incorporated is provided at the bottom of the main body 1, and the motor 4 is started by operating a switch lever 3 at the base of the handle 2. The speed reduction mechanism 6 is evenly arranged around the pinion gear 5, and three planetary gears 9, 9, ... Revolving while rotating by being meshed with the pinion gear 5 and a support shaft 10 of the planetary gear 9 are fixed to each other. The carrier 11 comprises a carrier 11 which is rotated by its revolution and is rotatably supported by a ball bearing 12. The carrier 11 is directly connected to the input shaft 7a of the impulse motor 7. An internal gear 13 is externally mounted on the three planetary gears 9, and the internal gear 13 is rotatably supported by a ball bearing 14 in a gear housing 1a fixed to the main body 1. Further, a slide member 15 is arranged between the internal gear 13 and the motor 4, and the slide member 15 is evenly arranged in three directions on the contact surface with the gear housing 1a in the axial direction as shown in FIG. The two steel balls 16 and 16 are half-embedded, and the steel balls 16 and 16 at these three positions are fitted into the slide grooves 1b and 1b provided in correspondence with the inner circumference of the gear housing 1a, whereby a slide member is formed. Reference numeral 15 is slidable back and forth in the gear housing 1a. The slide member 15 is urged toward the internal gear 13 side by two springs 17, 17, and the rotation of the normal internal gear 13 is restricted by this pressing force, and the rotation of the motor 4 causes a reduction mechanism. The planetary gear 9 of No. 6 revolves in the internal gear 13. Further, between the internal gear 13 and the slide member 15, the rear end surface of the internal gear 13 is provided with three equal cam grooves 18, 18 ... In the same manner as shown in FIG. Are formed with tapered surfaces 18a, 18a ,. On the other hand, on the front end surface of the slide member 15, fitting recesses 19, 19 ... Are provided at positions corresponding to the cam grooves 18, and half steel balls 20, 20 ... Are exposed in the fitting recess 19, respectively. It has been fitted.

In the impulse driver configured as described above, the motor shaft 4 a and the pinion gear 5 are rotated by the operation of the motor 4, and the carrier 11 and the impulse motor 7 and the output shaft 8 are rotated together with the revolution of the planetary gear 9, and the tightening is performed. Attach. When the load on the output shaft 8 increases with the tightening work and the rotation of the output shaft 8 is delayed from the rotation of the impulse motor 7, the impulse motor 7 generates an impact force due to hydraulic pressure. Is intermittently applied to the output shaft 8. At this time, the gap generated between the motor shaft 4a rotating at a constant speed and the reduction mechanism 6 rotating at a reduced speed of the output shaft 8 when an oil pulse is generated acts on the carrier 11 and the planetary gear 9 as a load in the rotational direction. To do. However, since the rotation motion of the motor shaft 4 and the planetary gear 9 does not change, this load acts on the internal gear 13, but the internal gear 13 acts on the slide member 15 to the extent that the planetary gear 9 can be orbited. Since it is only pressed and fixed, this load causes the internal gear 13 to rotate in the revolving direction of the planetary gear 9 against the bias of the slide member 15. At that time, as shown in FIG. 3, the tapered surface 18a of the cam groove 18 of the internal gear 13 rides on the steel ball 20 of the slide member 15, and at the same time, the slide member 15 slides the steel balls 16 and 16 in the slide groove 1b. The springs 17 and 17 retreat against the springs 17, and this operation can absorb the shock (load) when the oil pulse is generated. When the load is released, the steel ball 20 is fitted into the cam groove 18 again from above the tapered surface 18a by the pressing of the slide member 15 as shown in FIG. 1, and at the same time, the internal gear 13 rotates in the opposite direction to the above. Return to the position. The above operation is repeated with the generation of an oil pulse by the impulse motor 7. When the motor reversely rotates, the internal gear 13 naturally rotates in the opposite direction to the above, and the taper surface 18a on the side opposite to the above performs the riding and returning operation. The steel ball 20 and the cam groove 18 cannot be returned to their original positions when the steel ball 20 gets over the taper surface 18a due to the impact force of the impulse motor 7. Adjust the angle of surface 18a. Similarly, the urging of the slide member 15 by the spring 17 also increases or decreases the number of springs to adjust an appropriate urging force.

In the above-described embodiment, the steel ball 20 is interposed between the internal gear 13 and the slide member 15, so that the friction between both members is suppressed as much as possible, and the rotational operation of the internal gear 13 is made smooth. This is preferable because it can be performed, but instead of a steel ball, for example, a hemispherical projection is integrally provided on the front surface of the slide member to fit the cam groove, or a tapered surface corresponding to the cam groove is used instead of the spherical shape. Even if other engaging / disengaging mechanisms are adopted, such as by making the convex portions at both ends mesh with the cam groove, the cushioning action by the internal gear can be obtained. Of course, the cam groove and the corresponding balls or protrusions may be provided on the members opposite to those of the above-described embodiments. Further, the sliding between the steel ball 16 and the slide groove 1b between the slide member 15 and the gear housing 1a may be achieved by sliding not by the steel ball but by the projection and the concave groove, or by making the spline groove. . Further, the cam mechanism or the like as in the above embodiment may be provided between the internal gear and the pressing member (slide member), but the purpose of the present invention is to prevent the impact due to the oil pulse generation by the rotation of the internal gear. Since they are absorbed, they may be simply brought into surface contact with each other and only the pressing force for maintaining the internal gear in the semi-fixed state may be given to the pressing member.

[0009]

[Effect of device]

 As described above, according to the present invention, in the oil pulse rotary tool, the impact force of the oil pulse generator is buffered and the reaction to the internal mechanism is eliminated, so that gear wear and motor burnout are eliminated, and tool durability is also improved. improves.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an impulse driver to which the present invention is applied.

FIG. 2 is an explanatory diagram of a buffer mechanism in the above embodiment.

FIG. 3 is an operation explanatory view of the buffer mechanism in the above embodiment.

[Explanation of symbols]

1 ... Main body, 1a ... Gear housing, 2 ... Handle, 3 ... Switch lever, 4 ... Motor, 5 ... Pinion gear, 6 ... Reduction mechanism, 7 ... Impulse motor,
8 ... Output shaft, 9 ... Planetary gear, 10 ... Support shaft, 11 ...
・ Carrier, 12 ・ ・ Ball bearing, 13 ・ ・ Internal gear, 14 ・ ・ Ball bearing, 15 ・ ・ Slide member, 16 ・ ・ Steel ball, 17 ・ ・ Spring, 18 ・ ・ Cam groove, 18a ・ ・ Tapered surface , 19 ...
Fitting recess, 20 ... Steel ball.

Claims (2)

[Scope of utility model registration request] 1. A motor, a reduction mechanism having a planetary gear to which rotational force is transmitted from the motor, an internal gear mounted on the reduction mechanism, and an oil pulse generator connected to the reduction mechanism. In the electric oil pulse rotary tool having the above, the internal gear is rotatably supported in the housing, and a pressing member for pressing the internal gear by the biasing means is provided, and the pressing force of the biasing means is further provided. A buffer mechanism for an electric oil pulse rotary tool, wherein at least a fixed force of an internal gear required for the planetary gear of the speed reduction mechanism to revolve is set. 2. The pressing member is a slide member that is slidable in the axial direction of the tool and is biased toward the internal gear. Further, a plurality of balls are provided between the slide member and the internal gear. A ball fitting groove having tapered surfaces at both ends in the circumferential direction is formed on one of the facing surfaces corresponding to the ball, and a fitting concave portion for restricting the movement of the ball is formed on the other side. A buffer mechanism for an electric oil pulse rotary tool according to claim 1, which is a utility model registration claim.