JP5403309B2 - Rotating hammer tool - Google Patents

Description

  The present invention relates to a rotary impact tool such as an impact wrench or impact driver.

  A rotary impact tool, such as an impact wrench or impact driver, urges a hammer, which is coupled to a rotationally driven drive shaft via a cam, with a spring toward an anvil provided on an output shaft. The impact force is generated by impacting the anvil to the shaft, and the rotary impact force is generated. Since the reaction force applied to the operator's hand is small when tightening bolts, nuts, and screws, it has high workability. It has become.

  However, since such rotary impact tools generate intermittent rotational impact force, when drilling a metal (when used as a drill), the drill bit is missing or the rotational speed drops and the hole is drilled. There are things you can't do. 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. Such a rotary impact tool is proposed in Patent Document 1.

The hammering stop mechanism provided in the rotary hammering tool proposed in Patent Document 1 prevents the hammer from retreating by protruding a pin or the like from the outer frame to the hammer end surface, etc., and keeps the hammer always connected to the anvil. It is configured to stop the hammer from hitting the anvil. Then, when the pin or the like is retracted, the hammer can be retracted, and the hammer can perform an operation of applying a rotating impact force to the anvil.
JP-A-2-139182

  However, in the configuration proposed in Patent Document 1, no consideration has been given to friction between the hammer and a member such as a pin that prevents the hammer from moving backward.

  In addition, a spindle, and a hammer (according to the case where the impact is possible and the impact stop state, that is, the case where the rotary impact tool is used as an original rotary impact tool and the case where it is used as a simple drill for the purpose of drilling metal, (Or anvil) could not be arbitrarily switched.

  In addition, although drilling work can be performed as a drill, the provision of a torque clutch mechanism employed in an electric screwdriver or the like and a vibration mechanism for drilling in concrete has not been employed because of an increase in size.

  The present invention has been made in view of the above problems, and its object is to provide a rotary impact tool that can easily switch between impact operation and drill operation without increasing the size of the mechanism. It is in.

  Another object of the present invention is to provide a multi-function rotary impact tool capable of arbitrarily selecting an impact operation, a clutch torque operation, a drill operation and a vibration operation.

  In order to achieve the above object, a first aspect of the present invention is provided with a spring for biasing a hammer cam-coupled to a drive shaft toward an anvil which is an output shaft, and the hammer is intermittently engaged with the anvil by the cam and the spring. A rotary impact tool comprising a rotary impact mechanism that generates a rotational impact force by combining the hammer and an impact prevention mechanism that prevents the hammer from striking against the anvil and rotates the anvil integrally with the drive shaft. A rotatable ring having an inner surface formed with a cam groove, an outer ring having a pin engaging with the cam groove of the ring projecting on the outer periphery, and a plurality of spheres inside the outer ring so as to be rotatable When the ring is rotated, the outer ring, the sphere and the inner ring move in the axial direction toward the hammer side along the cam groove of the ring, and the inner ring is in close contact with the end surface of the hammer. Characterized in that so as to prevent axial movement of the hammer Te.

According to a second aspect of the present invention, in the first aspect of the present invention, the cup-shaped cap provided at the front part of the tool main body and the concave portions are formed on the opposing end surfaces of the ring, respectively. An impact operation is achieved by selectively engaging a cannula held in the axially movable case member interposed between either one of the recesses to prevent rotation of either the cap or the ring. And a drill operation can be selected.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, a first ratchet is integrally formed on an end surface of a slide bearing that rotatably supports the anvil, and the first ratchet is selected as the first ratchet. The second ratchet that is engaged with the anvil is bound to the outer periphery of the anvil.

  According to the first aspect of the invention, when the ring of the hit prevention mechanism is rotated from the outside, the outer ring, the sphere, and the inner ring move in the axial direction toward the hammer side, and the inner ring is brought into close contact with the end surface of the hammer. In order to prevent the hammer from moving in the axial direction, the impact operation can be switched to the drill operation, and if the ring is rotated in the reverse direction to release the inner ring from contacting the hammer, the hammer can be moved in the axial direction. The operation can be switched to the impact operation, and the switching between the impact operation and the drill operation can be easily performed without causing an increase in the size of the mechanism. Further, in the drilling operation, the inner ring of the hit prevention mechanism can be smoothly rotated with a small frictional resistance together with the hammer by the sphere. That is, the inner ring, the outer ring, and the sphere function as ball bearings.

  According to the second aspect of the present invention, either the cap or the ring is selectively engaged with the kanuki, which is held by the case member so as to be movable in the axial direction, with any one of the recesses formed in the cap and the ring. By preventing one of the rotations, an impact operation, a clutch torque operation, a drill operation, and a vibration operation can be arbitrarily selected, and the multi-functionalization of the rotary impact tool can be realized.

  According to the third aspect of the present invention, since the ratchet for generating the axial vibration in the anvil at the time of the vibration operation is integrally formed on the end surface of the slide bearing, the weight of the rotary impact tool can be reduced.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a cutaway side view of a rotary impact tool according to the present invention, FIG. 2 is a plan view of a ring constituting an impact prevention mechanism of the rotary impact tool, and FIG. 4 is a cross-sectional view taken along line AA of FIG. 3, FIG. 5 is a cross-sectional view taken along line BB of FIG. 3, FIG. FIG. 8 is a partial plan view showing the positional relationship between the ring, the cap, and the cannula during the impact operation of the rotary impact tool, and FIG. 8 shows the positional relationship between the ring, the cap, and the cannula when the impact operation of the rotary impact tool is blocked. FIG. 9 is a fragmentary side view showing the torque clutch operation of the rotary impact tool, FIGS. 10 and 11 are fragmentary side views showing the vibration operation of the rotary impact tool, and FIGS. FIG. 10 is a cross-sectional view taken along line C-C.

  As shown in FIG. 1, the rotary impact tool 1 according to the present embodiment includes a housing 2 having a T-shape when viewed from the side, and a body 3 </ b> A of the housing 2 includes a motor 3 as a drive source. Yes. A trigger switch 4 is disposed on the upper portion of the handle portion 2B extending substantially perpendicularly from the body portion 2A of the housing 2, and a rechargeable battery 5 is detachably mounted on the lower portion of the handle portion 2B.

  An inner cover 6 is disposed in the housing 2 and a bearing 7 is fixed at the center thereof. The output shaft of the motor 3 is inserted and held in the bearing 7, and a first pinion 8 is press-fitted and fixed to the tip of the output shaft. Around the first pinion 8, a plurality of first planetary gears 9 are rotatably arranged with a first pin 10 as a rotation shaft, and these first planetary gears 9 mesh with the first pinion 8. Further, the first planetary gear 9 is engaged with a ring gear 11, and the first pinion 8, the first planetary gear 9, and the ring gear 11 constitute a first stage reduction mechanism.

  The ring gear 11 is press-fitted into a ball bearing 12, and the ball bearing 12 is held in a bearing holder 13. The bearing holder 13 is coupled to the slide knob 14, and the ring gear 11 of the first-stage reduction mechanism is movable in the axial direction. The first stage reduction mechanism, the ball bearing 12 and the bearing holder 13 are housed in a reduction gear holder case 15. The ring gear 11 is located at the left end (rear end) in FIG. 1 on the inner wall of the reduction gear holder case 15 and the ring gear 11. Concave and convex portions are formed to lock the plate when it moves.

  The first planetary gear 9 is rotatably supported by a carrier 16 by a first pin 10, and the carrier 16 meshes with the ring gear 11. A second pinion 17 protrudes from the center of the right end of the carrier 16, and a plurality of second planetary gears 18 are arranged around the shaft 19 as a rotation shaft around the second pinion 17. The second planetary gears 18 are arranged on the second pinion 17. Is engaged. The second planetary gear 18 meshes with a second ring gear 20, and the second ring gear 20 is press-fitted into a holder 21 with a protrusion.

  The holder with protrusions 21 is rotatably held on the spindle 22 via a bearing 23 and is disposed with a gap with respect to the inner wall of the center housing 24 disposed on the right (front) side of the inner cover 6. Yes. The left end portion (rear end portion) of the spindle 22 constitutes a carrier portion of the second planetary gear 18, and this carrier portion supports the shaft 19.

  A plurality of cam grooves 22 a are formed slightly on the right side (front) of the center of the spindle 22. Balls 27 are formed in the cam grooves 26 a formed in the hammers 26 biased by the cam grooves 22 a and the springs 25. Are engaged. Here, the right end (front end) of the spring 25 is seated on the washer 28, and the hammer 26 is urged rotatably by the spring 25 via a ball 29. The left end (rear end) of the spring 25 is seated on the flange portion of the flanged washer 30. A flanged ring 31 is in contact with the left side (rear side) of the flanged washer 30, and a ring-shaped cushion 32 is interposed between the flanged washer 30 and the flanged ring 31. The cam groove 22a of the spindle 22, the cam groove 26a of the hammer 26, the ball 29 that engages with these cam grooves 22a and 26a, the spring 25 that urges the hammer 26 toward the anvil 33, and the like constitute a rotary impact mechanism. ing.

  Furthermore, an anvil 33 is rotatably held on the right side (front side) of the spindle 22, and a cylindrical portion formed at the right end of the spindle 22 is fitted into a hole at the left end of the anvil 33, so that the spindle 22 and the anvil 33 are fitted. Are pivotally supported by each other.

  Two arms 33a are formed on the left end (rear side) of the anvil 33 so as to extend in opposite directions in the radial direction, and two protrusions 26b extending from the right end of the hammer 26 are intermittently connected to the arm 33a of the anvil 33. Rotating impact force is transmitted to the anvil 33 by engaging with each other. A hexagon hole 33b for mounting a bit (not shown) for tightening a screw is formed on the right side (front side) of the anvil 33. The anvil 33 is a mechanical component for holding the bit. A sphere 34, a spring 35, a ring 36, a retaining ring 37, and a slide ring 38 are provided.

  The anvil 33 is rotatably supported by slide bearings 39 and 40, and a ratchet 41 is formed on the right end surface of the slide bearing 39 as shown in FIG. 5. A ratchet 42 is press-fitted into the anvil 33 so as to face the ratchet 41 of the slide bearing 39. A conical coil spring 43 is mounted on the right side (front side) of the bearing 40, and the switch plate 44 is urged by the coil spring 43. A ring-shaped groove is formed at the right end (front end) of the switch plate 44, and a sphere 45 is accommodated in the groove. Although not shown, metal washers are provided on both sides of the sphere 45, and the sphere 45 is prevented from coming off by retaining rings 61 fitted into the anvil 33.

  A front cover case 47 that rotatably holds the ring 46 is disposed on the right side (front side) of the center housing 24. In the vicinity of the center of the front cover case 47, a flange is provided on the outside and a partition is provided on the inside. Are provided. Further, a concentric pipe-like portion is formed on the right side (front side) of the partition wall, and the sliding bearing 39 is press-fitted and fixed inside thereof, and the sliding bearing 40 is also fixed. A screw is formed on the outside, and a nut 49 biased by a spring 48 is disposed. A cap 50 that is spline-fitted to the nut 49 is fixed to the outer side of the nut 49 by a cap presser 51 on the flange of the front cover case 47 so as to rotate concentrically with the shaft of the anvil 33. On the left side of the right end of the cap 50, a cylinder with a spline that is concentric with the shaft of the anvil 33 and accommodates the switch plate 44 in a locked state is formed. A switch washer 52 is disposed in contact with the left end of the switch plate 44. Has been.

  A cylinder 54 is disposed between the center housing 24 and the hammer 26 on the left side of the washer 53 on which the spring 48 is seated at the left end (rear end). A plurality of small columns 55 are disposed at the right end of the cylinder 54. These cylinders 55 pass through a hole provided in the central partition wall of the front cover case 47 and abut against the washer 53. A protrusion is formed on the left end surface of the cylinder 54, and this protrusion is engaged with the protrusion-equipped holder 21 by the urging force of the spring 48 so as not to rotate normally.

  Further, on the left side of the hammer 26, an impact preventing mechanism 56 for preventing the hammer 26 from retreating is provided. 2 to 4, the hit prevention mechanism 56 includes an inner ring 57, an outer ring 58, a sphere 59 arranged therebetween, a plurality of pins 58a protruding radially from the outer ring 58, and these pins 58a. The ring 46 is provided with a cam groove 46a for guiding (see FIG. 2).

  Furthermore, as shown in FIGS. 6-8, the recessed part 46b is formed in the right end surface (front end surface) of the ring 46, and the recessed part 50a is formed also in the left end surface (rear end surface) of the cap 50, In the wall of the front cover case 47, a rod-shaped kanuki 60 is disposed so as to be slidable in the axial direction.

  Next, operation | movement of the rotary impact tool 1 which has the above structure is demonstrated.

  FIG. 1 shows a state of an impact operation. When an operator pulls the trigger switch 4 to start the motor 3, the first pinion 8 rotates. Here, since the ring gear 11 is meshed with the gear formed on the outer periphery of the first planetary gear 9 and the carrier 16, the rotation of the first pinion 8 is transmitted to the second pinion 17 as it is. Since the second ring gear 20 is fixed, the second planetary gear 18 rotates around the second pinion 17 at a predetermined reduction ratio to rotate the spindle 22.

  When a load is applied to the anvil 33, when the hammer 26 moves back to a predetermined position against the biasing force of the spring 25 by the cam groove 26a, the hammer 26 moves forward while rotating, and a protrusion provided on the right end thereof. 26b strikes the arm 33a of the anvil 33 to transmit the rotational impact force to the anvil 33 and a bit (not shown). By repeating this operation, it is possible to tighten the thick bolt.

  FIG. 3 shows the state of the drill mode in which the impact operation is not performed. As shown in FIGS. 2 to 4, the ring 46 is rotated to advance the impact prevention mechanism 56 so that the left end of the hammer 26 is brought into close contact. Is prevented from moving (backward movement). At this time, since the pin 58a of the outer ring 58 is moved to a portion parallel to the end face of the ring 46 at both ends of the cam groove 46a provided in the ring 46, the impact prevention mechanism 56 cannot move in the axial direction, and the hammer 26 also moves backward. Can not. Accordingly, the hammer 26 rotates following the spindle 22. The rotation of the hammer 26 is transmitted to the anvil 33 by the protrusion 26b provided at the right end of the hammer 26 engaging the arm 33a of the anvil 33, and the anvil 33 rotates without being hit. In this case, when the slide knob 14 is moved backward, the ring gear 11 is locked and fixed to the speed reducer holder case 15, so that the first planetary gear 9 revolves and the first stage speed reducer functions to achieve a two-stage speed reduction. The output torque can be increased.

  Next, the operation of the cannula 60 during impact operation, drill operation, torque clutch operation, and vibration operation will be described with reference to FIGS.

As shown in FIGS. 6 and 7, during the impact operation, the kanuki 60 is inserted into the front cover case 47 so as to be movable in the axial direction. As shown in FIG. 7, the kanuki 60 protrudes into the recess 50 a of the cap 50, thereby making it impossible to rotate the cap 50. At this time, the cap 50 is fixed by impact operation .

  FIG. 8 shows a state in which the impact prevention mechanism 56 is in a position that prevents the hammer 26 from moving backward. At this time, since the cannula 60 protrudes into the recess 46b of the ring 46 and the ring 46 cannot be rotated, the cap 50 can be freely rotated, and a desired operation can be performed among the drill operation, the torque clutch operation, and the vibration operation. You can choose arbitrarily.

  FIG. 9 shows a state during operation of the torque clutch. In this state, the biasing force of the spring 48 is changed by changing the position of the nut 49 by turning the cap 50, and the sliding torque of the cylinder 54 and the holder 21 with protrusions is adjusted.

  Since the cylinder 54 is locked by other parts and cannot be rotated, when the holder 21 with the protrusion slides and rotates, the second ring gear 20 rotates together and the rotation of the spindle 22 stops. Accordingly, the anvil 33 is also stopped and can be screwed with a predetermined torque.

  10 and 11 show the state during the vibration operation.

  In the vibration operation, the state where the anvil 33 is prevented from moving in the axial direction because the phases of the switch washer 52 and the switch plate 44 do not match as shown in FIG. 12 (vibration operation OFF state) is changed to FIG. As shown in FIG. 10, when the cap 50 is rotated by a predetermined angle and the phases of the switch washer 52 and the switch plate 44 are matched, the anvil 33 can be moved in the axial direction as shown in FIGS.

  That is, in the state shown in FIG. 10, the anvil 33 is urged by the conical coil spring 43 and leans to the right side (front side), but when the tool body is pushed rightward (forward), as shown in FIG. Since the anvil 33 moves to the left (rear) and the ratchets 41 and 42 of the sliding bearings 39 and 40 mesh with each other, the anvil 33 can be vibrated when rotated.

  If it is desired to increase the vibration frequency during this vibration operation, the anvil 33 rotates at high speed by operating the slide knob 14 to advance the first-stage speed reducer, so that the vibration frequency of the anvil 33 can be increased. .

  As described above, in the present embodiment, when the ring 46 of the hit prevention mechanism 56 is rotated from the outside, the outer ring 58, the sphere 59, and the inner ring 57 move in the axial direction toward the hammer 26, and the inner ring 57 is moved to the hammer 26. In order to prevent the hammer 26 from moving in the axial direction (retracting) in close contact with the end surface of the hammer, the impact operation can be switched to the drill operation, and the ring 46 is rotated in the reverse direction to release the contact between the inner ring 57 and the hammer 26. Then, the hammer 26 can be moved in the axial direction and switched from the drill operation to the impact operation, and the switching between the impact operation and the drill operation can be easily performed without causing an increase in the size of the mechanism. In the drilling operation, the inner ring 57 of the hit prevention mechanism 56 can be smoothly rotated with a small frictional resistance together with the hammer 26 by the spherical body 59. That is, the inner ring 57, the outer ring 58, and the sphere 59 function as ball bearings.

  Further, according to the present embodiment, the cannula 60 held in the front cover case 47 so as to be movable in the axial direction is selectively engaged with either one of the recesses 50a and 46b formed in the cap 50 and the ring 46, respectively. By combining them to prevent the rotation of either the cap 50 or the ring 46, impact operation, clutch torque operation, drill operation and vibration operation can be arbitrarily selected, and the rotary impact tool 1 can be multifunctionalized. Can be realized.

  Furthermore, in the present embodiment, the ratchet 41 for causing the anvil 33 to vibrate in the axial direction during the vibration operation is integrally formed on the end surface of the slide bearing 39, so the weight of the rotary impact tool 1 can be reduced.

It is a fracture | rupture side view of the rotary impact tool which concerns on this invention. It is a top view of the ring which comprises the hit | damage prevention mechanism of the rotary impact tool which concerns on this invention. It is a principal part fracture side view which shows the drill operation | movement of the rotary impact tool which concerns on this invention. FIG. 4 is a sectional view taken along line AA in FIG. 3. FIG. 4 is a sectional view taken along line BB in FIG. 3. It is a principal part fracture side view which shows the impact operation | movement of the rotary impact mechanism which concerns on this invention. It is a fragmentary top view which shows the positional relationship of a ring at the time of impact operation | movement of the rotary impact tool which concerns on this invention, a cap, and a kanuki. It is a partial top view which shows the positional relationship of a ring, a cap, and a kanuki in the state by which the impact of the rotary impact tool which concerns on this invention was blocked | prevented. It is a principal part fracture side view which shows the torque clutch operation | movement of the rotary impact tool which concerns on this invention. It is a principal part fracture side view which shows the vibration operation | movement of the rotary impact tool which concerns on this invention. It is a principal part fracture side view which shows the vibration operation | movement of the rotary impact tool which concerns on this invention. It is CC sectional view taken on the line of FIG. It is CC sectional view taken on the line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotation impact tool 2 Housing 2A Housing body part 2B Housing handle part 3 Motor 4 Trigger switch 5 Battery 6 Inner cover 7 Bearing 8 First pinion 9 First planetary gear 10 First pin 11 Ring gear 12 Ball bearing 13 Bearing holder 14 Slide knob 15 Reduction gear holder case 16 Carrier 17 Second pinion 18 Second planetary gear 19 Axis 20 Second ring gear 21 Projection holder 22 Spindle (drive shaft)
22a Spindle cam groove 23 Bearing 24 Center housing 25 Spring 26 Hammer 26a Hammer cam groove 26b Hammer projection 27 Ball 28 Washer 29 Ball 30 Flange washer 31 Flange ring 32 Cushion 33 Anvil 33a Anvil arm 33b Anvil hexagon hole 34 Spherical body 35 Spring 36 Ring 37 Retaining ring 38 Slide ring 39, 40 Slide bearing 41, 42 Ratchet 43 Coil spring 44 Switch plate 45 Spherical body 46 Ring 46a Ring cam groove 46b Ring recess 47 Front cover case (case member)
48 Spring 49 Nut 50 Cap 50a Cap recess 51 Cap retainer 52 Switch washer 53 Washer 54 Cylinder 55 Cylinder 56 Strike prevention mechanism 57 Inner ring 58 Outer ring 58a Outer ring pin 59 Sphere 60 Cannuki 61 Retaining ring

Claims (3)

A rotary striking mechanism that includes a spring that biases the hammer cam-coupled to the drive shaft toward the anvil that is the output shaft, and generates a rotational striking force by intermittently engaging the hammer with the anvil by the cam and the spring; In the rotary impact tool having a striking prevention mechanism that prevents the hammering operation against the anvil and rotates the anvil integrally with the drive shaft.
The impact prevention mechanism includes a rotatable ring having a cam groove formed on its inner surface, an outer ring having a pin projecting on the outer periphery thereof, and a plurality of spheres inside the outer ring. With an inner ring arranged to be rotatable through,
When the ring is rotated, the outer ring, the sphere, and the inner ring move in the axial direction toward the hammer side along the cam groove of the ring, and the inner ring is brought into close contact with the end surface of the hammer to move the hammer in the axial direction. A rotary hitting tool characterized by blocking.   Recessed cup-shaped caps provided at the front of the tool body and recesses are formed in the opposite end faces of the ring, and held in a case member interposed between the cap and the ring so as to be movable in the axial direction. The impact operation and the drill operation are made selectable by selectively engaging one of the recesses with one of the recesses to prevent rotation of either the cap or the ring. The rotary impact tool according to 1.   A first ratchet is integrally formed on an end surface of a sliding bearing that rotatably supports the anvil, and a second ratchet that selectively engages the first ratchet is attached to the outer periphery of the anvil. The rotary impact tool according to claim 1 or 2.

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