JP4391921B2 - Vibration drill - Google Patents

Description

  The present invention relates to a vibration drill capable of imparting a vibration motion in an axial direction to a power shaft protruding in front of a housing by a vibration mechanism provided in the housing.

  As a vibration drill, for example, a drill having the vibration mechanism described in Patent Document 1 is known. This is because a spindle (output shaft) that is rotated by a motor is provided so as to be able to slightly move back and forth in the axial direction, and is urged to a forward position by an urging means such as a coil spring mounted on the spindle. When the first clutch that rotates is inserted into the housing, the spindle is loosely inserted and the second clutch facing the first clutch is fixed, and the bit attached to the spindle is pushed in to retract the spindle. Is capable of imparting an oscillating motion in the axial direction to the spindle by engaging both clutches.

  On the other hand, for mounting the bit on the spindle, a chuck provided on the spindle is used as disclosed in the same document, and a chuck sleeve provided on the tip of the spindle is provided so as to be movable back and forth in the axial direction with a predetermined stroke. At the same time, a biasing means such as a coil spring is urged to one of the front and rear sides, and a pressing member such as a ball, which is slidably moved in the radial direction of the spindle at a slide position by the urging, A structure is also often employed that allows the bit inserted into the insertion hole provided in the spindle to be fixed while being pressed to the side. When the chuck sleeve is slid to the opposite side against the biasing force, the pressing of the pressing member by the chuck sleeve is released, and the bit can be inserted and removed.

Japanese Utility Model Publication No. 51-14389

  Thus, in the above-described vibration drill, the urging means for urging the spindle to the forward position and the urging means for urging the chuck sleeve are provided separately, so that the number of parts is increased and the structure is complicated. As a result, the amount of time and effort required for assembly increased, leading to cost increases.

  Accordingly, an object of the present invention is to provide a vibration drill that can rationalize the output shaft and the bias of the chuck sleeve to achieve a simplified structure and a low cost. .

In order to achieve the above object, according to the first aspect of the present invention, the biasing direction of the chuck sleeve by the biasing means is set rearward, and the chuck sleeve is brought into contact with the housing side at the rearward sliding position. Thus, the biasing means of the chuck sleeve can bias the output shaft to the forward movement position.
The seismic drill as used in the present invention is a tool mainly having other functions such as an impact driver and a seismic driver drill, as well as a dedicated tool in which only a seismic mechanism is added to an output shaft to be driven to rotate. Including those with a vibration mechanism.

According to the invention described in claim 1, the biasing of the output shaft to the forward position and the biasing of the chuck sleeve to the backward position can be performed by only one biasing means provided on the chuck sleeve, It has a rational structure with a small number of parts. Therefore, it is possible to reduce assembling work and to reduce the manufacturing cost.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing an example of an impact driver provided with a vibration mechanism. The impact driver 1 is a rear portion of a main body housing 2 composed of a pair of left and right halved housings (the right side in FIG. 1 is the front). A planetary gear speed reduction mechanism 5, a striking mechanism 6 and a vibration mechanism 7 having a clutch mechanism are provided in front of the motor 3, respectively, and an output coaxial with the motor shaft 4 of the motor 3 is provided. An anvil 8 as a shaft protrudes forward. 9 is a switch of the drive circuit of the motor 3, and 10 is a trigger for turning on the switch 9 by pushing operation.
As shown in FIGS. 2 and 3, the planetary gear speed reduction mechanism 5 is coupled to the front of the motor bracket 11 and a cylindrical motor bracket 11 that is fixed in the main body housing 2 and supports the motor shaft 4. It is housed inside a cylindrical gear case 12 that is one size larger. That is, the three planetary gears 14, 14... Meshed with the pinion fitted to the motor shaft 4 and rotatable within the first internal gear 13, the carrier 15 that supports the planetary gear 14, and the carrier 15 , The next stage planetary gears 17, 17... That can rotate within the second internal gear 16, and the carrier part 19 that supports the planetary gear 17. 8 is formed of a spindle 18 that is coaxially inserted on the rear surface of the motor 8, and the rotation of the motor shaft 4 can be reduced to two stages and transmitted to the spindle 18.

  Here, the first internal gear 13 is rotatably supported by a ball bearing 20 in the motor bracket 11, and a speed switching ring 21 for holding the ball bearing 20 is also shown in FIG. As described above, the three protrusions 22, 22... Projecting in the axial direction on the outer surface, and the two guide grooves 23, 23 and one slit 24 recessed correspondingly in the motor bracket 11 By fitting, it is possible to move back and forth in the axial direction in a state where rotation is restricted. Of the three ridges 22 of the speed switching ring 21, the ridge 22 fitted into the slit 24 is provided with a connecting piece 25 projecting in the radial direction, and a rectangular frame provided outside the motor bracket 11. 26 is loosely inserted. The frame 26 is externally mounted on the motor bracket 11 and is provided so as to be movable back and forth between a forward position where it contacts the rear end of the gear case 12 and a backward position where it contacts a step provided on the inner surface of the main body housing 2. It is connected to the ring-shaped speed switching lever 27 in an orthogonal shape, and a groove 28 is formed on the outer periphery of the speed switching lever 27 in the circumferential direction except for the frame 26 portion. Further, in the frame 26, coil springs 29, 29 are inserted in the front and rear sides so as to sandwich the connecting piece 25.

  On the other hand, on the outer periphery of the gear case 12, an arc-shaped switching plate 31 having a switching button 30 protruding on the upper surface is provided. As shown in FIG. 4, the switching plate 31 exposes the switching button 30 to the outside through a horizontally long rectangular window 32 drilled in the left-right direction on the upper surface of the main body housing 2. Is movable in the circumferential direction of the gear case 12 within a range in which movement is restricted within the window 32. However, since a retreating portion 33 to which the switching button 30 can retreat is connected to the left end of the window 32, if the switching button 30 is slid into the retreating portion 33 at the left end, the switching plate 31 is moved backward. Can be moved. In addition, a rectangular and thin protective plate 34 that exposes only the switching button 30 is set on the upper surface of the switching plate 31, and always covers the entire surface of the window 32 regardless of the sliding position of the front, rear, left, and right of the switching button 30. To prevent intrusion of dust.

  On the inner surface of the switching plate 31, a coupling protrusion 35 that is inserted into the concave groove 28 of the speed switching lever 27 protrudes so that the speed switching lever 27 can follow the movement of the switching plate 31 in the front-rear direction. . Similarly, between the main body housing 2 and the protection plate 34, bent pieces 37, 37 formed downward on the left and right sides of the rear end are formed as a pair of flat L-shaped stoppers formed on the upper rear surface of the speed switching lever 27. A flat U-shaped display plate 36 which is locked on the outer side of each of the pieces 38 and 38 is set, and the switching button 30 can be fitted at the left end position of the window 32. The display plate 36 contributes to the connection between the speed switching lever 27 and the switching plate 31, and the display pieces 39, 39 positioned before and after the switching button 30 are placed in the window 32 according to the front and rear positions of the switching button 30. The numbers displayed on the surface are visible by alternately exposing them.

  Therefore, when the switching button 30 is operated at the left end position of the window 32 to move the switching plate 31 back and forth, the ball bearing 20 and the first internal gear 13 follow through the speed switching lever 27 and the speed switching ring 21. And move back and forth. Here, at the forward position of the first internal gear 13, the first stage planetary gear 14 and the carrier 15 are simultaneously meshed and integrated with each other, and at the reverse position, only the planetary gear 14 is meshed with the carrier 15. Leave. On the outer periphery of the rear end of the first internal gear 13, meshing teeth 40, 40... Project at equal intervals in the circumferential direction, and project on the bottom surface of the motor bracket 11 at the retracted position of the first internal gear 13. It engages with the provided meshing teeth 41, 41,... To restrict the rotation of the first internal gear 13. Therefore, at the retracted position of the first internal gear 13, the rotation of the motor shaft 4 of the motor 3 is transmitted to the carrier 15 by being decelerated by the planetary gear 14 revolving in the first internal gear 13, and the planetary gear reduction mechanism 5. Thus, the low-speed mode is reduced in two stages, and at the forward position of the first internal gear 13, the high-speed mode in which the rotation of the motor shaft 4 is directly transmitted to the carrier 15 is set.

  At this time, the display plate 36 exposes the rear display piece 39 in the retracted portion 33 of the window 32 at the forward position of the switching button 30 to display the number “2” indicating that it is in the high speed mode. At the retracted position of 30, the front display piece 39 is exposed in the window 32 and the number “1” indicating the low speed mode is displayed. Further, when the first internal gear 13 slides and meshes with the carrier 15 and the meshing teeth 41, even if the positions of the teeth are not aligned, the speed switching lever 27 is elastic of the coil springs 29 and 29. Since it can move to an appropriate position by deformation, the switching operation itself can always be performed smoothly. Since the urging by the coil springs 29 and 29 continues as it is, the first internal gear 13 and the speed switching ring 21 slide to the proper front and rear positions at the proper meshing position when the motor shaft 4 rotates.

  The second internal gear 16 is also provided so as to be able to rotate within the gear case 12 while holding a ball bearing 42 that pivotally supports the carrier portion 19 of the spindle 18, and the front and rear surfaces in the circumferential direction are inclined surfaces. Engaging projections 43, 43,... Are projected at equal intervals in the circumferential direction. In front of the second internal gear 16, a pressing ring 44 is fitted by an axial protrusion 45, 45... Formed on the outer surface of the pressing ring 44 and a not-shown concave groove formed in the inner surface of the gear case 12. Engagement projections 46 of the same shape that can be engaged with the engagement projections 43, 43,... Are accommodated on the rear surface facing the second internal gear 16 so as to be movable in the axial direction while being restricted in rotation. 46 are projected at equal intervals in the circumferential direction. On the other hand, a coil spring 50 whose front end is received by a pair of pushers 47, 47 is disposed in front of the pressing ring 44 so that the pressing ring 44 can be urged rearward. The pushers 47, 47 are provided on the outer surface of the gear case 12 in a point-symmetrical manner around the shaft center, and stopper pieces 48, 48 protruding from the inner surface are passed through openings 51, 51 formed in the gear case 12. The stopper pieces 48 and 48 receive the front end of the coil spring 50 through the washer 52 by a plate-like body protruding inward. Male screw portions 49 are formed on the outer surfaces of the pushers 47, 47, respectively.

  Therefore, the rotation of the second internal gear 16 is restricted by the engagement with the pressing ring 44 obtained by the urging force of the coil spring 50. A cylindrical change ring 53 having a female screw part formed on the inner periphery is rotatably mounted on the gear case 12 in front of the main body housing 2 and screwed with the male screw part 49 of the pushers 47 and 47. When the pushers 47 and 47 are moved in the axial direction by rotating the change ring 53, the coil spring 50 can be expanded and contracted in the axial direction to change the urging force to the pressing ring 44. A leaf spring 54 is fitted on the outer periphery of the front end of the gear case 12 and engaged with teeth 55, 55... Formed on the inner periphery of the front end of the change ring 53. It has come to be obtained. 56 is a hammer case that is fixed to the gear case 12 by screwing in front of the change ring 53 and pivotally supports the anvil 8. A ring-shaped rubber bumper 114 is fitted to the front portion of the hammer case 53, Along with the screw marks, the workpiece is prevented from being damaged by the contact of the front portion of the impact driver 1.

  On the other hand, on the outer periphery of the second internal gear 16, as shown in FIG. 6 (A), the protrusions 58, 58.. The ring-shaped clutch switching lever 57 whose rotation is restricted by fitting with the recessed grooves 59, 59,... Is mounted so as to be movable back and forth in the axial direction. The engagement teeth 60, 60,... Provided and the engagement teeth 61, 61,... Provided on the rear outer periphery of the second internal gear 16 engage with each other, regardless of the urging force of the coil spring 50. The rotation of the internal gear 16 can be restricted. On the outer surface of the clutch switching lever 57, a pair of connecting projections 62, 62 project in a point-symmetrical position in the radial direction and pass through slits 63, 63 formed in the axial direction to the gear case 12. Protruding to

  A semi-cylindrical switching case 64 that is slightly larger than the gear case 12 is rotatably mounted on the outer periphery of the gear case 12. The switching case 64 has a switching plate 31 fitted in a notch portion at the rear end and rotates integrally following the circumferential slide of the switching plate 31, and is formed at a point symmetrical position at the rear end portion. The coupling protrusions 62 of the clutch switching lever 57 are inserted into the pair of clutch switching grooves 65, 65, respectively. As shown in FIG. 5A, each clutch switching groove 65 includes a first groove 66 along the circumferential direction of the switching case 64 and a second circumferentially located second position located behind the first groove 66. The connecting protrusion 62 is formed of a groove 67 and an inclined groove 68 that connects the first groove 66 and the second groove 67 and is restricted from moving in the circumferential direction within the slit 63 as the switching case 64 rotates. Is relatively moved in the clutch switching groove 65, the clutch switching lever 57 can be moved back and forth from the outside via the connection protrusion 62. Here, the clutch switching lever 57 is in the forward position when the connecting projection 62 is positioned in the first groove 66, and the clutch switching lever 57 is in the reverse position when it is positioned in the second groove 67.

  The striking mechanism 6 includes an anvil 8 that is pivotally supported via ball bearings 69 and 69 on a small cylindrical portion 12 a and a hammer case 56 provided at the front end of the gear case 12, and a spindle 18 that is coaxially inserted into the rear surface of the anvil 8. And a hammer 70 mounted on the spindle 18, and a coil spring 72 that receives the rear end by a cup washer 71 mounted on the spindle 18 and biases the hammer 70 forward. As shown in FIG. 6B, the hammer 70 is formed in a pair of cam grooves 73 and 73 formed in a V shape on the outer peripheral surface of the spindle 18 and in the axial direction on the inner peripheral surface of the hammer 70. The steel ball 75 is connected to the spindle 18 by two steel balls 75, 75 fitted across the connection grooves 74, 74, and the steel ball 75 is connected to the front end (V-shaped tip) of the cam groove 73 and the connection by the coil spring 72. It is urged to the forward movement position located at the rear end of the groove 74. On the front surface of the hammer 70, a pair of fan-like engagement claws 77, 77 projecting from the front that can be engaged with a pair of arms 76, 76 extending radially to the rear end of the anvil 8 are projected. In the forward position of the hammer 70 shown in FIG. 1, the engaging claws 77 and 77 engage with the arms 76 and 76 to rotate the hammer 70 and the anvil 8 together.

  An auxiliary ring 78 is externally mounted on the hammer 70 so as to rotate integrally and move independently in the axial direction by fitting with a two-sided width. On the front surface of the auxiliary ring 78, arc-shaped auxiliary claws 79, 79 continuously projecting from the outer peripheries of the engaging claws 77, 77 of the hammer 70 are projected, and the engaging claws 77 of the hammer 70 are in the forward position. , 77 and the arms 76, 76. Further, a concave groove 80 is formed in the circumferential direction on the outer periphery of the auxiliary ring 78. On the other hand, in the switching case 64, rectangular guide bodies 82, 82 having a cylindrical body 82a fitted in the center are accommodated in a pair of slits 81, 81 formed in the axial direction so as to be movable back and forth. As shown in FIGS. 5 (A) and 6 (B), the stepped pin 83 fitted into the cylinder 82a of the body 82 passes through a pair of impact switching grooves 84, 84 formed in the gear case 12. The tip is loosely inserted into the concave groove 80 of the auxiliary ring 78.

  The impact switching groove 84 is formed of a first groove 85 formed in the circumferential direction of the gear case 12 and a second groove 86 bent in a V shape rearward in the middle of the first groove 85. With the rotation of 64, the stepped pins 83 and 83 are moved in the impact switching grooves 84 and 84 together with the guide bodies 82 and 82 that are restricted from moving in the circumferential direction in the slit 81, whereby the stepped pin 83 is moved. The auxiliary ring 78 can be moved back and forth from the outside. Here, the advance position of the auxiliary ring 78 is obtained in a state where the stepped pin 83 is located in the first groove 85, and the retracted position of the auxiliary ring 78 is obtained in a state where it is located at the V-shaped tip of the second groove 86. In the impact switching groove 84, a cylindrical body 82a of a suitable guide body 82 that is externally mounted on the stepped pin 83 slides. Such a double structure with the cylindrical body 82a and the stepped pin 83 ensures the strength of the stepped pin 83, allows the stepped pin 83 to slide within the impact switching groove 84 and the auxiliary ring 78. This is for the purpose of reliably moving.

  The vibration mechanism 7 is installed in the hammer case 56. The vibration mechanism 7 includes a first cam 87 that is integrally fitted to the anvil 8 between the ball bearings 69, 69, and a separate exterior to the anvil 8 behind the ball 88, 88, and a flat washer 89. The second cam 90 whose rearward movement is restricted by the second cam 90, and the locking teeth 91, 91 formed on the outer periphery of the second cam 90 in the small cylinder portion 12a of the gear case 12 behind the second cam 90. .. A ring-shaped vibration switching lever 93 having front and rear engaging teeth 92, 92,... Which can be engaged with each other, and the first cam 87 and the second cam 90 abutting against each other Cam teeth 94, 95,... Meshing with each other in the state are formed.

As shown in FIG. 6C, the vibration switching lever 93 is formed by fitting projections 96, 96,... Projecting on the outer periphery and recesses 97, 97,. A pair of connecting projections 98, 98 which are held so as to be movable back and forth in the small tube portion 12a in a state where the rotation is restricted, and which protrude radially outwardly between the projections 96, 96 are provided on the small tube portion 12a. The slits 99 and 99 are penetrated and loosely inserted into a pair of arcuate guide plates 100 and 100 protruding from the front end of the switching case 64. As shown in FIG. 7, a first groove 102 along the circumferential direction of the switching case 64 and a trapezoidal shape forward in the middle of the first groove 102 are formed in the loose insertion portion of the connection protrusion 98 in each guide plate 100. The vibration switching groove 101 formed by the second groove 103 that is bent in the direction is formed, and the connection protrusions 98, 98 that are restricted from moving in the circumferential direction in the slit 99 as the switching case 64 rotates are connected to the vibration switching groove 101. By moving relatively within 101, 101, the vibration switching lever 93 can be moved back and forth from the outside via the connecting projection 98. Here, the retreat position of the vibration switching lever 93 is obtained when the connection protrusion 98 is located in the first groove 102, and the forward movement position of the vibration switching lever 93 is obtained when it is located at the front end of the trapezoid of the second groove 103.
Here, since the switching case 64 is made of synthetic resin, the portions including the rear edge of the second groove 103 in the guide plate 100 are formed separately by the steel plates 104 and 104, respectively, and the vibration switching groove 101 is formed. The strength of is secured.

Next, the rotation position of the switching case 64 associated with the operation of the switching button 30 and the operation mode obtained along with the rotation position will be described.
First, as shown in FIG. 7, the switching button 30 is the first of the switching case 64 that is the first sliding position of the left end of the window 32 (upper side of FIG. 4, described with the anvil 8 as the front. The same applies hereinafter). In the rotational position, the coupling protrusion 62 of the clutch switching lever 57 is positioned at the right end of the first groove 66 in the clutch switching groove 65. Therefore, the clutch switching lever 57 is in the forward position and restricts the rotation of the second internal gear 16. In the impact switching groove 84, the stepped pin 83 is positioned at the left end of the first groove 85. Therefore, the auxiliary ring 78 is in the forward movement position and is engaged with the arm 76. Further, in the vibration switching groove 101, the connection protrusion 98 is positioned at the right end of the first groove 102. Therefore, the vibration switching lever 93 is in the retracted position and is away from the second cam 90.
Therefore, here, the second internal gear 16 is directly prevented from idling by the clutch switching lever 57, and the anvil 8 is in a drill mode in which it rotates integrally with the spindle 18 via the auxiliary ring 78. At this time, since the second cam 90 is free to rotate, vibration does not occur even if it makes contact with the first cam 87.

Next, as shown in FIG. 8, at the second rotational position of the switching case 64 in which the switching button 30 moves from the first sliding position to the right side by about one third of the horizontal dimension of the window 32, the clutch switching is performed. In the groove 65 and the vibration switching groove 101, the connecting protrusions 62 and 98 are not changed in the first grooves 66 and 102, respectively, so that the forward movement position of the clutch switching lever 57 and the backward movement position of the vibration switching lever 93 are not changed. However, in the impact switching groove 84, the stepped pin 83 enters the second groove 86 and moves to the V-shaped tip. Therefore, the auxiliary ring 78 moves backward from the arm 76.
Therefore, at the second slide position of the switch button 30, the second internal gear 16 is prevented from idling regardless of the load on the anvil 8, the second cam 90 is also free to rotate and no vibration is generated, but the spindle 18 And the anvil 8 becomes an impact mode connected via a hammer 70.

Next, as shown in FIG. 9, at the third rotational position of the switching case 64 where the switching button 30 moves to the right by about one third of the horizontal dimension of the window 32 from the second sliding position, In the clutch switching groove 65, the connection protrusion 62 remains unchanged in the first groove 66. However, in the impact switching groove 84, the stepped pin 83 enters the first groove 85 again, and moves the auxiliary ring 78 to the advanced position. Further, in the vibration switching groove 101, the connecting protrusion 98 enters the second groove 103 and moves to the trapezoidal front end. Therefore, the vibration switching lever 93 moves forward and restricts the rotation of the second cam 90.
Therefore, at the third slide position of the switching button 30, the second internal gear 16 is prevented from idling regardless of the load on the anvil 8, and the anvil 8 rotates integrally with the spindle 18. The anvil 8 is provided at a forward position where the front surface of the arms 76, 76 comes into contact with the nylon washer 105 which is externally mounted on the anvil 8 and held by the small cylinder portion 12 a of the gear case 12, and at the step of the front end of the spindle 18. The first cam 87 that rotates together with the anvil 8 is restricted by the vibration switching lever 93 at the retracted position of the anvil 8 because it is housed so as to be movable in the front-rear direction with respect to the retracted position where the rear surface abuts. The vibration drill mode in contact with the second cam 90 is set.

As shown in FIG. 10, in the fourth rotational position of the switching case 64 in which the switching button 30 is positioned at the right end of the window 32, the connection projection 62 is secondly guided by the inclined groove 68 in the clutch switching groove 65. Moving into the groove 67, the clutch switching lever 57 is retracted. Further, in the impact switching groove 84, the stepped pin 83 is at the right end of the first groove 85, and therefore the advance position of the auxiliary ring 78 does not change. However, in the vibration switching groove 101, the connecting protrusion 98 moves backward from the second groove 103 and moves to the left end of the first groove 102. Thus, the vibration switching lever 93 moves backward from the second cam 90.
Therefore, at the fourth slide position of the switch button 30, the anvil 8 rotates integrally with the spindle 18 and no impact is generated, and the second cam 90 is also free to rotate and no vibration is generated. By reversing, the second internal gear 16 enters a clutch mode in which it is fixed only by the urging force of the coil spring 50.

  3 and 6A, the steel ball 106 is accommodated together with the coil spring 107, and the steel ball 106 is projected and biased toward the back surface of the switching plate 31. ing. Since the recesses 108, 108... Corresponding to the four slide positions of the switching button 30 are formed in two rows in the front and rear direction on the outer peripheral surface of the gear case 12, A click action corresponding to the position and the speed switching position is obtained.

  On the other hand, a chuck sleeve 109 is mounted on the outer periphery of the tip of the anvil 8 so as to be movable back and forth in the axial direction with a predetermined stroke. It is urged to a retracted position that contacts the inner ring 69. At this retracted position, the protrusion 111 protruding from the inner periphery of the chuck sleeve 109 presses the balls 112 and 112 as pressing members inserted in the anvil 8 so as to be movable in the radial direction toward the axial center. Then, a bit (not shown) inserted into the insertion hole 113 is fixed to prevent the bit from being inserted into the insertion hole 113 having a hexagonal cross section provided in the axial center of the anvil 8. When the chuck sleeve 109 is slid forward against the bias of the coil spring 110, the pressing of the ball 112 by the protrusion 111 is released, so that the bit can be inserted into and removed from the insertion hole 113.

In particular, here, the chuck sleeve 109 urged backward is brought into contact with the ball bearing 69, so that the anvil 8 is normally in the advanced position by the urge of the coil spring 110, and the first cam 87, the second cam 90, Is maintained in a non-contact state. When the bit mounted on the anvil 8 is pressed against a screw head or the like and the anvil 8 is moved backward, the cam teeth 94 and 95 of the first cam 87 and the second cam 90 come into contact with each other.
Although the chuck sleeve 109 abutting on the ball bearing 69 relatively moves forward due to the retreat of the anvil 8, the advance distance is small and the pressing state against the ball 112 does not change. Fixation is maintained.

  In the impact driver 1 configured as described above, first, the switch button 30 is operated to the first slide position to select the drill mode of FIG. 7, and in this state, the trigger 10 is pushed in and the switch 9 is turned on. As a result, the motor 3 is driven and the motor shaft 4 rotates. Then, the rotation of the motor shaft 4 is decelerated by the planetary gear reduction mechanism 5 and transmitted to the spindle 18. Since the spindle 18 is connected to the anvil 8 not only by the hammer 70 but also by the auxiliary ring 78 in the forward position, the anvil 8 always rotates integrally with the spindle 18 and no impact is generated in the striking mechanism 6. Also in the vibration mechanism 7, since the vibration switching lever 93 is free, no vibration is generated even if the anvil 8 moves backward. Therefore, a drilling operation using a drill bit or the like attached to the anvil 8 is possible. At this time, as described above, since the rotation of the second internal gear 16 is restricted by the clutch switching lever 57, the clutch mechanism does not work, and the rotation of the anvil 8 continues regardless of the load on the anvil 8.

  Next, when the switch button 30 is operated to the second slide position to select the impact mode of FIG. 8 and the switch 9 is turned on, the rotation of the spindle 18 is transmitted to the anvil 8 via the hammer 70. Therefore, when screwing with a driver bit inserted into the anvil 8, when the load on the anvil 8 is increased, the steel balls 75, 75 are rolled backward along the cam grooves 73, 73 of the spindle 18, The hammer 70 moves backward against the bias of the coil spring 72 and moves away from the arms 76, 76 of the anvil 8. However, at the moment when the engaging claws 77 and 77 are separated from the arms 76 and 76, the coil claws 72 move forward together with the spindle 18 by the bias of the coil spring 72, and the engaging claws 77 and 77 are reengaged with the arms 76 and 76. . By repeating the separation and engagement of the hammer 70 with respect to the anvil 8, an impact (impact) is intermittently generated in the rotational direction on the anvil 8, and retightening is performed. At this time, no vibration is generated in the vibration mechanism 7, and the clutch mechanism does not work by fixing the second internal gear 16.

  Next, when the switch button 30 is operated to the third slide position to select the vibration drill mode of FIG. 9 and the switch 9 is turned on, the hammer 70 and the anvil 8 are connected by the auxiliary ring 78, so No impact is generated in the mechanism 6, and the clutch mechanism does not work by fixing the second internal gear 16. However, in the vibration mechanism 7, the rotation of the second cam 90 is restricted by the vibration switching lever 93. Therefore, when the anvil 8 is moved backward by pressing a drill bit or the like, the first cam 87 that rotates integrally with the anvil 8 is the first cam 87. The anvil 8 is vibrated in the axial direction by contact with the two cams 90 and the cam teeth 94 and 95 interfering with each other.

  When the switch button 30 is operated to the fourth slide position to select the clutch mode and the switch 9 is turned on, the connection state of the hammer 70 and the anvil 8 by the auxiliary ring 78 does not change, and the impact mechanism 6 has an impact. Does not occur. In addition, since the second cam 90 is also free, no vibration is generated in the vibration mechanism 7 even if the anvil 8 moves backward. However, in the planetary gear speed reduction mechanism 5, since the rotation restriction of the second internal gear 16 by the clutch switching lever 57 is released, the screw tightening proceeds and the load on the anvil 8 and the spindle 18 is pressed by the coil spring 50. Is exceeded, the engagement protrusion 43 of the second internal gear 16 pushes the pressing ring 44 forward to get over the engagement protrusion 46, so that the second internal gear 16 idles and the screw tightening is finished. This clutch operating torque can be adjusted by changing the compression amount of the coil spring 50 by rotating the change ring 53.

In each of the above operation modes, as described above, the switching plate 31 slides to the left and right at the front position by the guidance of the switching button 30 by the window 32, so that the first internal gear 13 together with the speed switching ring 21 is The anvil 8 rotates in a high speed mode in which the planetary gear 14 and the carrier 15 are coupled to each other at the forward movement position in the rotation free state.
On the other hand, if the switching button 30 is retracted only at the first slide position in the drill mode, the first internal gear 13 is retracted together with the speed switching ring 21 to restrict the rotation, and meshes only with the planetary gear 14. Therefore, the anvil 8 rotates in the low speed mode. That is, the anvil 8 can be switched between high speed and low speed only in the drill mode.

  As described above, according to the impact driver 1 of the above-described form, the biasing direction of the chuck sleeve 109 by the coil spring 110 is set to the rear, and the chuck sleeve 109 is brought into contact with the ball bearing 69 on the main body side at the rearward sliding position. By making contact, the anvil 8 can be biased to the forward position by the coil spring 110, and the chuck sleeve 109 is provided with a bias toward the forward position of the anvil 8 and a bias toward the backward position of the chuck sleeve 109. This can be performed by only one coil spring 110, and a rational structure with a small number of parts is obtained. Therefore, it is possible to reduce assembling work and to reduce the manufacturing cost.

The biasing means of the chuck sleeve may be constituted by a coil spring, other members such as a leaf spring and an elastic body, or a combination thereof, and the contact of the chuck sleeve with the housing side is limited to the ball bearing. Of course, it may be in other places such as a hammer case or washer. As the pressing member, a roller or the like can be employed in addition to the ball.
In the above embodiment, the impact driver that can select four operation modes of the drill mode, the impact mode, the vibration drill mode, and the clutch mode is described, but the vibration driver and the bit insertion structure by the chuck sleeve are provided. As long as it is an electric tool, other electric tools such as a vibration driver drill may be used, and of course, a vibration drill having only a vibration mechanism may be used. In the case of such a dedicated tool, there is no need for a means for switching between rotation restriction and release of the second cam as in the above embodiment, and the second cam is always fixed in the housing.

It is a longitudinal cross-sectional view of an impact driver. It is a disassembled perspective view of an internal mechanism. It is a disassembled perspective view of an internal mechanism. It is a top view of an impact driver. (A) is a side view of a gear case part, (B) is an AA sectional view. (A) is a BB line sectional view, (B) is a CC line sectional view, and (C) is a DD line sectional view. The top is a side view of the gear case portion in the drill mode, and the bottom is a longitudinal sectional view (however, the change ring and the hammer case are shown). The top is a side view of the gear case portion in the impact mode, and the bottom is a longitudinal sectional view (however, the change ring and the hammer case are shown). The top is a side view of the gear case portion in the vibration drill mode, and the bottom is a longitudinal sectional view (however, the change ring and the hammer case are shown). The top is a side view of the gear case portion in the clutch mode, and the bottom is a longitudinal sectional view (however, a change ring and a hammer case are shown).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Impact driver, 2 ... Body housing, 3 ... Motor, 4 Motor shaft, 5 ... Planetary gear reduction mechanism, 6 ... Stroke mechanism, 7 ... Vibration mechanism, 8 ... Anvil, 12 ... Gear case, 13 ... First internal Gear, 16 second internal gear, 18 spindle, 21 speed switching ring, 27 speed switching lever, 30 switching button, 31 switching plate, 32 window, 44 pressing ring, 53 change ring, 57 ... Clutch switching lever, 62, 98 Connection protrusion, 64 ... Switching case, 65 ... Clutch switching groove, 70 ... Hammer, 78 ... Auxiliary ring, 83 ... Stepped pin, 84 ... Impact switching groove, 87 ... First cam , 90, second cam, 93, vibration switching lever, 101, vibration switching groove.

Claims (1)

An output shaft that is rotated by the drive of a motor is provided in front of the housing so as to be able to slightly move back and forth in the axial direction, and the output shaft is vibrated in the axial direction at the retracted position of the output shaft in the housing. While providing an oscillating mechanism that can be applied, the front end of the output shaft can be moved back and forth in the axial direction with a predetermined stroke, and a chuck sleeve that is urged to one of the front and rear slide positions by an urging means, A bit inserted into the insertion hole of the output shaft by pressing a pressing member provided in the output shaft so as to be movable in the radial direction at the slide position of the chuck sleeve toward the axial center of the output shaft A seismic drill that can prevent
The biasing direction of the chuck sleeve by the biasing means is set to the rear, and the output shaft is advanced by the biasing means by bringing the chuck sleeve into contact with the housing side at a sliding position at the rear. A seismic drill characterized by being able to be biased to a position.

Images