JP2009184040A - Spinning impact tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spinning impact tool capable of facilitating switching between impact operation and drill operation by operation of an operation member, and being used for multi-purposes by changing output frequency by operation of the second operation member and adjusting output of impact operation with one spinning impact tool. <P>SOLUTION: A joint member for jointing a driving shaft with an anvil and a speed reduction mechanism on the second stage are made to be separately movable, while enabling impact operation at both of high and low speeds as conventional. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotary impact tool such as an impact wrench or impact driver used for tightening bolts, nuts, or screws.

  An impact rotary tool such as an impact wrench or impact driver uses a spring that urges a hammer that is coupled to a rotationally driven drive shaft via a cam toward the anvil provided on the output shaft. It creates rotational force by impacting the anvil. The impact rotary tool has high workability because it requires less reaction force applied to the operator's hand when tightening bolts, nuts, and screws.

  However, because of the intermittent impact rotational force, when drilling a metal (when used as a drill), the drill bit is missing or the rotational speed drops and cannot be drilled.

For this reason, it is necessary to limit the movement of the hammer in the axial direction so that an impact operation cannot be obtained, that is, to prevent the hammer from leaving the anvil.

  Here, there was one disclosed in Japanese Patent No. 3911905. This striking stop mechanism is an impact rotary tool provided with switching means for making an anvil supported so as to be relatively rotatable with respect to the drive shaft in a state in which the anvil is not relatively rotatable, and rotates relative to the drive shaft and the drive shaft. A connecting member that interlocks with the operation of the operating portion for external operation input by providing an engaging portion that engages with the connecting member of the odd-shaped cross section column on each of the anvils that are supported in the drive shaft and the anvil, respectively. If the operating unit is operated using the switching means, the connecting member changes the state relating to the relative rotation between the drive shaft and the anvil to switch between the impact operation and the drill operation.

  A conventional example will be described with reference to FIGS.

  FIG. 5 shows the impact operation. A state in which the hammer 5 performs a striking motion is shown by moving a hexagonal column connecting member 36 connecting the drive shaft 4 and the anvil 6 to the drive shaft side. In this case, the rotational force is transmitted to the anvil 6 through the first-stage planetary speed reduction mechanism 3, the drive carrier 24, the connection coupling portion 71, the transmission carrier 70, the drive shaft 4, the steel ball 57, and the hammer 5. In this case, there is only one set reduction ratio. Therefore, there is only one kind of rotational impact force.

  FIG. 6 shows the case of clutch operation. The connection member 36 of a hexagonal column is moved to connect the drive shaft 4 and the anvil 6 so that the drive shaft 4 and the anvil 6 rotate together. In this case, the rotational force is transmitted to the anvil 6 via the first-stage planetary speed reduction mechanism 3, the drive carrier 24, the second-stage planetary speed reduction mechanism 3 a, the transmission carrier 70, the connection coupling portion 71, the drive shaft 4, and the connection member 36. When the load is large, the torque clutch 7 operates and the ring gear 28 of the second stage planetary reduction mechanism idles to cut off the rotational force. The function is an electric driver with a general clutch.

Japanese Patent No. 3911905

  Recently, in an impact driver, it has been required to produce not only a large impact torque of 100 Nm or more but also a small impact torque with the same tool. This can be implemented by a switch having a speed change function for changing the rotational speed of the motor, but since the reproducibility of the rotational speed is poor, it is required to be implemented mechanically using a speed reducer.

  However, in the structure shown in Japanese Patent No. 3911905, the number of revolutions during impact operation and drill operation is determined respectively, and when adjusting the impact rotational force, use a switch with a variable speed function. There was a need to work while. This operation is inferior in reproducibility of the rotational speed as described above.

  The present invention has been made in view of the above points, and the main object of the present invention is to provide a two-stage transmission mechanism that mechanically performs high-speed rotation and low-speed rotation in an impact operation to provide two types of rotational impact forces. Is to provide. Another object of the present invention is to provide a rotary tool capable of regulating the impact rotational force by making a clutch mechanism that has become common in an electric screwdriver or the like to function during an impact operation.

  According to the present invention, the connecting member for connecting the drive shaft and the anvil and the second-stage reduction mechanism can be moved separately to enable the high-speed impact operation and the low-speed impact operation as before. Thereby, a weak rotational striking force can be obtained from the anvil. Further, since the clutch mechanism can function during a low-speed impact operation, the weak rotational impact force can be further adjusted to several types of small rotational impact forces. As a result, ordinary impact drivers can be tightened even with thin screws that rotate and cut the shaft. Although this operation can be performed even if the speed of the motor is decreased by using a speed change switch, the above method is excellent in ease of use.

  According to the present invention, in the impact operation, either one of the two rotation speeds of the high speed rotation and the low speed rotation can be selected, and the rotation impact force can be transmitted to the anvil. Therefore, the types of screws to be tightened are increased and the usability of the tool is improved. .

  Further, since the clutch mechanism can be operated during the impact operation, the rotational impact force can be set finely, and the screws can be tightened with a rotational force intermediate between the conventional continuous tightening mode and the impact tightening mode.

  Further, by separating and independently operating members for switching between impact operation and non-impact operation and switching between high-speed rotation and low-speed rotation, the rotational speed of the drive shaft can be selected, and efficient work can be performed.

  Hereinafter, a rotary tool according to an embodiment of the present invention will be described with reference to FIGS.

  In FIG. 1, the main body decelerates the output of the motor 2 by the planetary speed reduction mechanism 3 and transmits it to the drive shaft 4, and impacts the impact output by striking the anvil 6 integrated with the output shaft 60 by the hammer 5 attached to the drive shaft 4. A battery-driven portable device that can be taken out, and a battery 45 as a power source is attached to the lower end of the grip portion 10 extending from the housing 1, and is attached to the base portion of the grip portion 10. Is provided with a switch 11. In the figure, 12 is a trigger switch handle.

The impact mechanism composed of the drive shaft 4, the hammer 5, the anvil 6, the spring 55 for biasing the hammer 5 toward the anvil 6 and the spring receiver 56 is the same as that of the conventional one, and the groove shape provided on the outer periphery of the drive shaft 4 A steel ball 57 is engaged with the cam 41 and a groove-shaped cam 51 provided on the inner peripheral surface of the hammer 5. When the drive shaft 4 rotates, the hammer 5 that rotates with the drive shaft 4 and engages the protrusion 52 with the anvil 6 by the bias of the spring 55 rotates the anvil 6 and the output shaft 60. When the torque increases, the hammer 5 rotates relative to the drive shaft 4 and retracts against the spring 55 according to the cam lead. When the protrusion 52 gets over the anvil 6, the hammer 5 moves forward according to the lead of the cam by the urging force of the spring 55, and the impact is applied to the anvil 6 in the rotation direction by the protrusion 52.
Between the motor 2 and the drive shaft 4, a speed reducer comprising the planetary speed reduction mechanism 3 is arranged as described above. The planetary speed reduction mechanism 3 is connected to the sun gear 20 fixed to the output shaft of the motor 2 and the motor. A planetary gear 22 meshing with a ring gear 21 fixed to the mounting base 19 is supported by two carriers 23 and 24 in the front and rear in the axial direction, and in particular, a drive carrier on the front side in the axial direction (output shaft 60 side). Reference numeral 24 is provided so as to be slidable in the axial direction, and provided with an engaging portion 25 slidable in the axial direction by a key connection such as a spline or serration at the rear end portion of the drive shaft 4. Yes. The rotation of the motor 2 is decelerated by the planetary reduction mechanism 3 and transmitted to the drive shaft 4 through the drive carrier 24.

  On the other hand, a switching pin 35 is slidably disposed at the central portion of the drive shaft 4 and the drive carrier 24, and an engagement portion 42 is provided as a recess at the tip of the drive shaft 4, and the engagement is performed. A connecting member 36 for directly connecting the drive shaft 4 and the output shaft 60 is disposed in the portion 42. The switching pin 35 whose rear end is fixed to the disk 47 by press-fitting or the like has a regular hexagonal cross section with the connecting member 36 and the engaging portion 42 at a portion having a small diameter at the tip thereof, and is integrated with the rotation. In addition, the slide in the axial direction can be freely performed.

  The rear end surface of the output shaft 6 includes a holding portion 63 into which the tip end portion of the drive shaft 4 fits freely and an engaging portion 64 that can engage with the connecting member 36. The engaging portion 64 also has a regular hexagonal cross section, and is freely slidable in the axial direction with respect to the connecting member 36 and is integrally rotated.

On the outer surface of the housing 1, an operation member 15 is slidable in the front-rear direction. The operation member 15 has an elastic body 17 made of a piano wire fixed to the inner surface thereof, and is engaged with an annular groove 26 provided on the outer peripheral surface of the drive carrier 24. Similarly, the operation member 15a is slidably disposed in the front-rear direction at a position rotated by approximately 90 ° from the operation member 15, and an elastic body 17a made of a piano wire is fixed to the inner surface side of the operation member 15a. Is engaged with an annular groove 26a provided on the outer peripheral surface of the. (See Figure 4)
As shown in FIG. 1, when the operating portions 15 and 15a are retracted, the drive carrier 24 and the disk 47 are in the retracted state, and the connecting member 36 connected to the disk 47 by the switching pin 35. Is located in the engaging portion 42 of the drive shaft 4. If the motor 2 is driven in this state, the rotation of the motor 2 is decelerated by the planetary reduction mechanism 3 and is output from the drive shaft 4 to the output shaft 60 via the hammer 5 and the anvil 6. When a load exceeding a certain level is applied to the output shaft 60, an impact operation is performed by intermittent impact coupling between the hammer 5 and the anvil 6 by the impact mechanism. At this time, since the drive carrier 24 and the disc 47 are rotatable with respect to the movable bars 16 and 16a, no rotational load is applied.

  On the other hand, as shown in FIGS. 3 and 4, when the operation members 15 and 15a are slid forward, the drive carrier 24 and the disk 47 advance through the elastic bodies 17 and 17a, and at this time, the connecting member 36 is driven. The engaging portion 42 of the shaft 4 and the engaging portion 64 of the output shaft 60 are engaged with each other, and the rotation of the drive shaft 4 is transmitted to the output shaft 60 via the connecting member 36. The drive shaft 4 and the anvil 6 (output shaft 60) are in a directly connected state incapable of relative rotation. In this way, the connection state between the drive shaft 4 and the anvil 6 is switched by operating the connection member 36 positioned inside the drive shaft 4 and the anvil 6 (output shaft 60) with the operation members 15 and 15a from the outside. In addition, the impact and drill can be easily switched by an external operation.

  In order to make the tightening torque adjustment function work when the drive shaft 4 and the output shaft 6 are directly connected and used, the following is performed. A torque clutch 7 is added, and the torque clutch 7 is disposed between the planetary reduction mechanism 3 a and the drive shaft 4. That is, the planetary gear 29 held by the transmission carrier 70 and the freely rotatable ring gear 28 are arranged in the tip end portion of the gear case 18, and the planetary gear 29 is meshed with the sun gear 27 and the ring gear 28 provided on the drive carrier 24. ing.

  Further, a male screw is formed on the outer peripheral surface of the front end portion of the gear case 18 and an adjustment screw 77 is screwed together to cover the outside of the impact mechanism and to rotate around the axis with respect to the housing 1. A part of the adjustment screw 77 is slidably engaged with a groove 130 provided on the inner surface of the part cover 13.

  Further, the gear case 18 is provided with a hole penetrating in the axial direction, and a steel ball 74 is disposed in the hole, and a thrust plate 75 and a clutch spring 76 are interposed between the steel ball 74 and the adjusting screw 77. A protrusion 73 is provided on the front end surface of the ring gear 28 so as to engage with the steel ball 74. In the figure, 72 is a pin for preventing the ring gear 28 from moving in the axial direction.

  The transmission carrier 70 includes a connecting and coupling portion 71 with the rear end portion of the drive shaft 4, and the sun gear 27 and the planetary gear 29 in the drive carrier 24 are slidable in the axial direction.

  In this case, when it is desired to obtain an impact operation, the disk 47 and the connecting member 36 are moved backward by operating the operating member 15a as shown in FIG. At the same time, the drive carrier 24 is moved backward to bring the drive carrier 24 and the transmission carrier 70 into the direct connection state by the engagement of the direct connection gear 80 and the engagement portion 81, and the drive shaft 4 is rotated. Then, the rotation of the motor 2 is transmitted to the drive shaft 4 through the planetary speed reduction mechanism, and an impact output due to impact engagement between the hammer 5 and the anvil 6 is applied to the output shaft 60.

  At this time, since the sun gear 27 of the drive carrier is not meshed with the planetary gear 29 supported by the transmission carrier 70, the torque clutch 7 does not operate.

  For use as a driver with tightening torque management, as shown in FIG. 2, the operation members 15 and 15a are operated to advance the disk 47 and the drive carrier 24, and the direct connection provided on the drive carrier 24 is used. The gear 80 is removed from the engaging portion 81 with the transmission carrier 70, the sun gear 27 provided on the drive carrier 24 is meshed with the planetary gear 29, and the drive shaft 4 and the output shaft 60 are directly connected by the connecting member 36. For this reason, the rotation of the motor 2 is further decelerated by the sun gear 27, the ring gear 28, the planetary gear 29, and the transmission carrier 70 provided on the drive carrier 24 after being decelerated by the planetary reduction mechanism 3, and transmitted to the drive shaft 4. It is transmitted to the output shaft 60 that is directly connected to the shaft 4 by the connecting member 36. If the load torque increases, the ring gear 28 starts idling, so that the rotation transmission is interrupted and the tightening torque is limited.

  Since the torque at this time corresponds to the amount of compression of the clutch spring 76 by the adjusting screw 77, the tightening torque can be managed by adjusting the position of the adjusting screw 77 by rotating the drive unit cover 13. The flange provided near the left end of the drive cover 13 is provided with an uneven portion that engages with a click spring 79 attached between the end faces of the housing 1 to generate clicks, thereby facilitating management of tightening torque. is there. In the figure, reference numeral 95 denotes a holding ring 95 for attaching the drive cover 13 to the housing 1 in a rotatable manner.

  When it is desired to use as an electric drill, the operation members 15 and 15a may be advanced with the torque clutch 7 rotating the drive unit cover 13 in FIG. The connecting member 36 moves forward via the drive carrier 24 and the switching pin 35, and the connecting member 36 directly connects the drive shaft 4 and the output shaft 60, and the impact mechanism is canceled.

  FIG. 3 shows a case where an impact operation is performed by decelerating the rotational speed by two steps and using a torque clutch. When the operation member 15a (see FIG. 4) is moved backward from the state of use with the driver shown in FIG. 2 and the disc 47, the switching pin 35 and the connecting member 36 associated therewith move, the output shaft 60 can perform an impact operation. become. When the load torque of the output shaft 60 increases, an impact output due to shocking engagement between the hammer 5 and the anvil 6 is applied to the output shaft 60. In this case, since the rotation of the hammer 5 is low and the torque clutch is further activated, the impact output can be regulated.

  In addition, the lead wire which connects the motor 2, the switch 11, and the battery 45 was not illustrated.

It is a longitudinal cross-sectional view at the time of impact operation | movement of the rotary impact tool which concerns on embodiment of this invention. It is a longitudinal cross-sectional view at the time of clutch operation | movement at the time of impact operation same as the above It is a longitudinal cross-sectional view at the time of clutch operation same as the above. It is sectional drawing of FIG. It is a longitudinal cross-sectional view at the time of impact operation of a conventional example. It is a longitudinal cross-sectional view at the time of the clutch operation | movement of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 .... Housing 2 .... Motor 3, 3a ... Planetary speed reduction mechanism 4 .... Drive shaft 5 .... Hammer 6 .... Anvil 7 .... Torque clutch 10 .... Grip part 11 .... Switch 12 .... Trigger handle 13 .... · Driver cover 15, 15a ·· Operation member 17, 17a ·· Elastic body 18 ·· Gear case 19 ·· Motor mounting portion 20 ·· Sun gear 21 ·· Ring gear 22 ·· Planetary gear 23 ·· Carrier 24 ·· Drive carrier 25 .. Engagement part 26, 26a .. Groove 27 .. Sun gear 28 .. Ring gear 29 .. Planetary gear 35 .. Switching pin 36. Connection member 41. Cam 42. Engagement part 45. Battery 47. · · Disc 51 · · Cam 52 · · Projection 55 · · Spring 56 · · Receiving 57 ·· Steel ball 60 · · Output shaft 63 · · Holding portion 64 · · Engagement portion 70 · · Transmission carrier 71 · · Connection coupling portion 72 · · Pin 73 · · projection 74 · · · steel ball 75 · · · Slide plate 76 ・ ・ Clutch spring 77 ・ ・ Adjust screw 79 ・ ・ Click spring 80 ・ ・ Direct connection gear 81 ・ ・ Engagement part 95 ・ ・ Presser ring 130 ・ ・ Groove

Claims (4)

  Provided with a spring that urges a hammer cam-coupled to the drive shaft toward the anvil provided on the output shaft, and an impact mechanism that generates rotational force by impacting the anvil against the hammer by the cam and spring In addition, the rotary impact tool having a planetary speed reduction mechanism that decelerates the rotation speed of the motor and transmits it to the drive shaft, and has a torque clutch mechanism provided so that the ring gear of the planetary speed reduction mechanism rotates at a constant rotational load. A rotary impact tool characterized by not preventing the mechanism and the torque clutch mechanism from working simultaneously.   In the rotary tool according to claim 1, when a plurality of planetary speed reducer mechanisms are used to decelerate a plurality of stages, when the planetary speed reducing mechanism is set to the earliest rotational speed, the torque clutch mechanism does not function and other rotational speeds are set. When set to, the rotary impact tool is characterized in that the torque clutch mechanism functions.   An impact mechanism that includes a spring that urges a hammer that is cam-coupled to a drive shaft toward an anvil provided on an output shaft, and that generates rotational force by impactably engaging the anvil with the hammer by the cam and spring. And a switching means for making an anvil supported to be rotatable relative to the drive shaft in a state in which the anvil is not rotatable relative to the drive shaft, and is supported to be rotatable relative to the drive shaft. An engaging portion that engages with the connecting member is provided on both of the anvils, and the connecting member that interlocks with the operation of the operation portion for external operation input is used as a switching means. The engaging portion and the engaging portion of the anvil are for switching between a state in which the engaging portion of the driving shaft and the anvil are simultaneously engaged and a state in which the engaging portion is not engaged with at least one of the engaging portions. of The intermediate transmission member is movably supported in the axial direction, and the connection member and the operation member are connected to the intermediate transmission member that is rotationally connected to the drive shaft by key connection. In the impact rotary tool operated via the intermediate member, an operation unit for external operation input linked with the connecting member and an operation unit for external operation input linked with the intermediate transmission member are respectively provided. A rotary impact tool characterized by being provided.   4. The rotary impact tool according to claim 3, wherein two types of external operation input operation portions provided in the housing above the grip portion of the handle are separated by 45 ° or more in angle.

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