JP4596366B2 - Vibration drill - Google Patents

Description

  The present invention relates to a vibration drill having a function of imparting rotation and vibration to a drill.

  This type of vibration drill is used for drilling work materials such as concrete, mortar, tiles, etc., and its basic configuration is as follows.

  That is, the vibration drill is provided with a spindle that is rotationally driven by a motor so as to be movable in the axial direction, and a second ratchet disposed so as to be non-rotatable and axially movable facing the first ratchet attached on the spindle, The second ratchet is configured to be urged by a spring in a direction in which a claw formed on the second ratchet engages with a claw formed on the first ratchet.

  By the way, in such a vibration drill, a drill mode that gives only rotation to the drill and a vibration drill mode that simultaneously gives rotation and vibration to the drill can be selected as operation modes. When the vibration drill mode is selected, the spindle can move in the axial direction. When the drill is pressed against the work material, the second ratchet moves in the axial direction with respect to the spindle together with the main body frame. The second ratchet abuts on the first ratchet, and the claws of both engage.

  Thereafter, the second ratchet moves in the axial direction while compressing the spring. However, when the pressing force of the drill against the work material increases and the amount of compression of the spring also increases, the second ratchet moves to the side wall member fixed to the main body frame. Since the second ratchet is in direct contact, the vibration of the second ratchet propagates as it is to the main body frame through the side wall member, and the vibration of the main body frame is increased, causing discomfort and fatigue to the operator. It was.

  Therefore, an proposal has been made that an elastic body is provided on the inner peripheral surface of the side wall member facing the outer peripheral surface of the second ratchet, and vibration is absorbed by the elastic body to suppress vibration propagation to the main body frame (Patent Document). 1).

Further, in Patent Document 1, the spring constant of a spring that biases the second ratchet toward the first ratchet is set such that the second ratchet does not contact the side wall member when a pressing force of 15 to 25 kgf is applied to the main body frame. By setting the value to such a value, the second ratchet, which is a source of vibration, is kept floating with respect to the main body frame, thereby suppressing vibration propagation from the second ratchet to the main body frame and reducing the operator's trouble. It describes that pleasure and fatigue can be reduced.
JP 2005-052905 A

  However, in the configuration proposed in Patent Document 1, when a pressing force exceeding 25 kgf is applied to the main body frame, the second ratchet contacts the side wall member and compresses the elastic body in the axial direction. Has a shape that has a large contact area with the second ratchet and is difficult to compress and deform, and therefore cannot effectively suppress vibration propagation to the main body frame, reducing operator discomfort and fatigue. It was not enough to do.

  The present invention has been made in view of the above problems, and the object of the present invention is to suppress the propagation of vibrations to the main body frame even when a large pressing force is applied to the main body frame, thereby discomforting the operator. Another object is to provide a vibration drill that can reduce fatigue.

In order to achieve the above object, the invention according to claim 1
A motor as a drive source;
A spindle driven to rotate by the motor and movable in the axial direction;
A first ratchet bound on the spindle;
A second ratchet that has a pawl that can be engaged with the pawl of the first ratchet, and is non-rotatable and movable in the axial direction;
A spring for urging the second ratchet toward the first ratchet;
A body frame housing the motor, spindle, first ratchet, second ratchet and spring;
In a vibration drill comprising
A movable member supporting one end of the spring on the side opposite to the second ratchet is provided in the body frame so as to be movable in the axial direction, and a fixed member fixed to the body frame is disposed on the side opposite to the second ratchet of the movable member. provided further provided an elastic member that contact area, and increases the compression progresses of the spring by the axial movement of the second ratchet between said movable member and said fixed member, said movable member side from the second ratchet a cylindrical portion extending provided, the movable member side end portion of the tubular portion into contact with said movable member thereby elastically deforming the elastic member through the movable member when a large pressing force to the body frame is applied Thus, the vibration of the second ratchet is absorbed by elastic deformation of the elastic member.

The invention according to claim 2
A motor as a drive source;
A spindle driven to rotate by the motor and movable in the axial direction;
A first ratchet bound on the spindle;
A second ratchet that has a pawl that can be engaged with the pawl of the first ratchet, and is non-rotatable and movable in the axial direction;
A spring for urging the second ratchet toward the first ratchet;
A body frame housing the motor, spindle, first ratchet, second ratchet and spring;
In a vibration drill comprising
The second ratchet has a cylindrical shape and is provided with an inner cylinder part and an outer cylinder part that extend rearward along the axial direction of the spindle, and the second ratchet is slidable in the axial direction. The spring is provided between the inner tube portion and the outer tube portion of the second ratchet, and the movable member inserted through the outer periphery of the inner tube portion of the second ratchet is A second ratchet is provided so as to be able to move along the outer periphery of the inner cylinder part, and is attached to the main body frame so as not to slide, and a fixing member inserted through the outer periphery of the inner cylinder part of the second ratchet. Provided behind the movable member, an elastic member is interposed between the movable member and the fixed member, the spring is positioned between the second ratchet and the movable member, and the drill is pressed against the work material in front Wherein deforming the elastic member when the second ratchet and the movable member is retracted, characterized in that so as to prevent contact of the fixed member and the movable member.

  According to the present invention, since a large pressing force is applied to the main body frame, the second ratchet comes into contact with the support member. Therefore, even if vibration is not absorbed by the spring, vibration from the second ratchet is not caused by the support member. Since it is effectively absorbed by the elastic deformation of the elastic member, vibration propagation to the main body frame is suppressed, and discomfort and fatigue of the operator holding the main body frame can be reduced.

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

  1 is a cutaway side view of a vibration drill according to the present invention, FIG. 2 is a cutaway side view of a main portion of a tip showing a state in the drill mode of the vibration drill, FIG. 3 is an enlarged detail view of a main portion of FIG. FIG. 5 is a cutaway side view of the main part of the tip showing a state of the vibration drill in the vibration drill mode.

  As shown in FIG. 1, the vibration drill 1 according to the present invention includes a main body frame 2 that is a resin molded product. The main body frame 2 includes a housing 3, a fan casing 4, an intermediate cover 5, and a gear cover 6. Are assembled and integrated. In the housing 3 of the main body frame 2, a motor 7 as a drive source is horizontally accommodated in a horizontal state. A handle portion 3a bent at a substantially right angle downward is integrally formed at the rear end portion of the housing 3, and an electric cord 8 is introduced into the handle portion 3a from below. The electric cord 8 is connected to the motor 7 through a switching mechanism (not shown) built in the handle portion 3a. The handle portion 3a is provided with a trigger switch 9 for operating the switching mechanism to turn on / off the power to the motor 7.

  By the way, both ends of the output shaft (motor shaft) 10 of the motor 7 are rotatably supported by bearings 11 and 12, and at one end thereof (a front end protruding forward from the front bearing 11). The pinion gear 13 is integrally formed. A centrifugal cooling fan 14 housed in the fan casing 4 is attached to the front end of the output shaft 10 (the rear part of the front bearing 11), and the cooling fan of the fan casing 4 is attached. A plurality of exhaust ports 15 (only one is shown in FIG. 1) are formed around 14. A plurality of air inlets 16 are formed on the left and right of the rear portion of the housing 3.

  As shown in detail in FIG. 2, a spindle 17 and an intermediate shaft 18 are disposed in parallel to the output shaft 10 of the motor 7 in the gear cover 6, and both ends of the spindle 17 are bearings 19 and 20. Is supported so as to be rotatable and movable in the axial direction. Also, the intermediate shaft 18 is rotatably supported at both ends by bearings 21 and 22, and three gears 23, 24 and 25 having large and small diameters are provided in the intermediate portion at appropriate intervals in the axial direction. The gear 23 meshes with the pinion gear 13 formed on the output shaft 10 of the motor 7.

  By the way, a drill chuck 26 for detachably mounting a drill (bit) (not shown) is attached to the tip portion of the spindle 17 protruding outward from the gear cover 6, and is attached to the tip opening portion of the gear cover 6. Is provided with an oil seal 27 slidably contacting the outer peripheral surface of the spindle 17.

  As shown in FIG. 2, gears 28 and 29 having different diameters are integrally fitted on the outer periphery of the rear half of the spindle 17 so as to be slidable in the front-rear direction. , 29 are slid back and forth on the spindle 17 by a shifter 33 that slides along a guide shaft 30 arranged in parallel to the spindle 17.

  Here, a speed switching dial 31 is rotatably provided on the outer periphery of the gear cover 6, and a pin 32 is erected at a position eccentric from the rotation center of the speed switching dial 31. The pin 32 is engaged with a long hole (not shown) formed in the channel-shaped shifter 33 that holds the gears 28 and 29 from both sides, and the rotational movement of the speed switching dial 31 is caused by the pin 32. It is converted into the movement of the shifter 33 in the front-rear direction. Accordingly, as shown in FIG. 2, from the state where the small-diameter gear 29 is engaged with the large-diameter gear 24 on the intermediate shaft 18 side, the speed change dial 31 is turned to shift the gears 28 and 29 to the spindle 17 by the shifter 33. If the large-diameter gear 28 is engaged with the small-diameter gear 25 on the intermediate shaft 18 side, the speed reduction ratio is largely switched and the speed of rotation transmitted from the intermediate shaft 18 to the spindle 17 is increased. While being lowered, the rotational torque of the spindle 17 is increased.

  A cylindrical first ratchet 34 is attached to the spindle 17 at a position behind the bearing 19. A double cylindrical second ratchet 34 is disposed adjacent to the first ratchet 34 on the spindle 17. The ratchet 35 is inserted so as to be slidable in the axial direction and non-rotatable in the circumferential direction, and the spindle 17 can freely rotate with respect to the second ratchet 35. In addition, concave and convex claws 34a and 35a that can be selectively engaged are formed on the opposing end surfaces of the first ratchet 34 and the second ratchet 35, respectively. A spring 36 that urges the two ratchets 35 in the direction (rearward) away from the first ratchet 34 is shrunk.

  Here, on the outer peripheral side of the second ratchet 35, a cylindrical sleeve 37 fitted to the inner periphery of the gear cover 6 is arranged. As shown in FIG. Rotation is prevented by engaging a projection 37a projecting from the portion with an engagement groove 6a formed on a part of the inner periphery of the gear cover 6, and a second ratchet 35 is slid back and forth on the inner periphery. The spline is movably fitted.

  As shown in detail in FIG. 3, a support member 38 is fitted and disposed at a position adjacent to the sleeve 37 in the gear cover 6, and the support member 38 is an inner cylinder portion 35 a of the second ratchet 35. An O-ring 41 is provided as an elastic member between a fixed ring 39 and a movable ring 40 inserted through the outer periphery of the ring. Here, the fixing ring 39 is fixed with its axial position regulated by a snap ring 42 fitted to the inner periphery of the gear cover 6, and its front end surface is in contact with the rear end surface of the sleeve 37. On the other hand, the movable ring 40 can be moved back and forth along the outer periphery of the inner cylindrical portion 35b of the second ratchet 35, and between the fixed ring 39 and the pressing force acting on the movable ring 40 is 400N or less. A predetermined gap is always ensured, and metal contact with the fixing ring 39 is avoided. A spring 43 is compressed between the movable ring 40 and the second ratchet 35, and the second ratchet 35 is always urged forward (to the first ratchet 34 side) by the spring 43. Nitrile butyl rubber (NBR) is used as the material of the O-ring 41.

  Thus, the vibration drill 1 according to the present embodiment can select the drill mode and the vibration drill mode as the operation mode. Hereinafter, the operation mode switching mechanism will be described.

  As shown in FIG. 1, a pin 44 that can rotate around a vertical axis that is perpendicular to the axis center of the spindle 17 is provided in the intermediate cover 5. A notch-shaped recess 44a is formed.

  A mode changeover switch 45 is provided on the outer periphery of the intermediate cover 5 so as to be movable in the circumferential direction. When the mode changeover switch 45 is turned in the circumferential direction, the turning operation moves the axis of the pin 44. The operation is switched to the half-rotation operation around the center, and the cylindrical outer peripheral surface or the notch-shaped recess 44 a of the pin 44 is selectively directed to the rear end portion of the spindle 17. As a result, the rear end portion of the spindle 17 selectively comes into contact with the outer peripheral surface of the pin 44 or the concave portion 44a via the ball 46, and the operation mode is switched to the drill mode or the vibration drill mode as described later.

  Next, the operation of the vibration drill 1 configured as described above will be described below by dividing it into a drill mode and a vibration drill mode.

1) Drill mode:
In the drill mode, as shown in FIG. 2, the rear end of the spindle 17 is in contact with the cylindrical surface of the pin 44 via the ball 46. In this state, as shown in detail in FIG. The second ratchet 35 urged forward is in contact with a convex portion 37 b formed on the inner periphery of the front end portion of the sleeve 37, and its axial movement is locked. Accordingly, the second ratchet 35 is separated from the first ratchet 34, and an axial gap is formed between the two ratchets 34, 35 as shown in the figure. The claws 34a, 35a of the two ratchets 34, 35 are It is in a disengaged state.

Thus, when the motor 7 is driven by turning on the trigger switch 9 and energizing the motor 7 during the drilling operation by the vibration drill 1, the output shaft 10 of the motor 7 is rotationally driven at a predetermined speed. The rotation is decelerated by the pinion gear 13 and the gear 23 and transmitted to the intermediate shaft 18, and the intermediate shaft 18 is rotationally driven at a predetermined speed. In the example shown in FIG. 2, the rotation of the intermediate shaft 18 is decelerated by the gears 24 and 29 that mesh with each other and transmitted to the spindle 17, and the drill chuck 26 attached to the spindle 17 and its tip. and drill (not shown) mounted thereto are rotated at a predetermined speed. At this time, since the first ratchet 34 and the second ratchet 35 are separated from each other as described above, the second ratchet 35 is in an immobile state, and vibration (striking) is applied from the second ratchet 35 to the spindle 17. Instead, the spindle 17 continues to rotate without moving in the axial direction. Incidentally, the gear 28, 29 is advanced along the spindle 17 by turning the speed SWITCHING dial 31 as described above, if the mesh with the gear 28 of the large diameter side to the small-diameter gear 25 of the intermediate shaft 18 side, the reduction ratio Is largely switched to reduce the rotation speed transmitted from the intermediate shaft 18 to the spindle 17 and increase the rotational torque of the spindle 17.

  Then, when the drill is rotationally driven as described above, if the main body frame 2 of the vibration drill 1 is gripped and the drill is pressed against the work material (not shown), the drilling work of the work material by the drill is performed. However, in the drill mode, the relative positional relationship between the first ratchet 34 and the second ratchet 35 is unchanged even when the main body frame 2 is pressed against the work material side, and both ratchets 34 and 35 are Since they are separated from each other, no vibration is applied to the spindle 17, and the spindle 17, the drill chuck 26, and the drill continue to rotate without vibration, and the work material is drilled by the drill.

2) Vibration drill mode:
The pin 44 by operating the mode switching exchange switch 45 is half-rotated, if facing the recess 44a of the pin 44 to the rear end of the spindle 17, the operation mode is switched from the drill mode to the vibration drill mode, the In the vibration drill mode, the spindle 17 can move rearward by the depth of the recess 44 a of the pin 44.

  Thus, in this vibration drill mode, as in the drill mode, the rotation of the output shaft 10 of the motor 7 is decelerated and transmitted to the spindle 17, but no load is applied before the drill is pressed against the work material. In the state, the first ratchet 34 and the second ratchet 35 are separated from each other by the urging force of the spring 36, and the spindle 17, the drill chuck 26 and the drill are not vibrated, and only rotate. It is.

  In this state, when the main body frame 2 of the vibration drill 1 is gripped and the drill is pressed against a work material (not shown), the main body frame 2 moves forward with respect to the spindle 17 while compressing the spring 36. The two ratchets 35, the sleeve 37 and the support member 38 also move forward integrally. As shown in FIG. 4, the second ratchet 35 abuts against the first ratchet 34 and then compresses the spring 43 to the biasing force. The sleeve 37 moves backward in the sleeve 37, and the rear end portion of the outer cylinder portion 35 c comes into contact with the movable ring 40 of the support member 38. For this reason, the movable ring 40 moves rearward along the outer periphery of the inner cylindrical portion 35a of the second ratchet 35, and compresses the O-ring 41 between the movable ring 40 and the movable ring 40. A predetermined axial clearance is secured between the ring 39 and the fixing ring 39, and metal contact between the rings 39 and 40 is avoided.

  Thus, in this vibration drill mode, when the second ratchet 35 comes into contact with the first ratchet 34 as described above, the claws 34a, 35a of both ratchets 34, 35 are engaged with each other, together with the spindle 17, the first ratchet. As a result, the claw 35a of the second ratchet 35 gets over the claw 34a of the first ratchet 34, and the second ratchet 35 repeats abutting / separating operation with respect to the first ratchet 34. Since it vibrates in the axial direction and this vibration is transmitted from the spindle 17 to the drill via the drill chuck 26, the drill is also vibrated simultaneously with the rotation, and the drilling work of the work material by the drill is efficiently performed.

  By the way, the vibration generated in the second ratchet 35 has a small pressing force against the work material of the drill, and in the state where the second ratchet 35 does not contact the movable ring 40 of the support member 38, the vibration is mainly generated by the spring 43. Since the vibration is effectively absorbed by the expansion and contraction and the vibration propagation to the main body frame 2 is suppressed, discomfort and fatigue given to the operator holding the handle portion 3a of the main body frame 2 are reduced.

  Then, when the pressing force of the drill against the work material increases and the second ratchet 35 makes metal contact with the movable ring 40 of the support member 38 as shown in FIG. 4, the spring 43 does not perform the vibration absorbing function. Since the O-ring 41 performs a vibration absorbing function in place of the spring 43, the vibration of the second ratchet 35 is effectively absorbed by the elastic deformation of the O-ring 41, and vibration propagation to the main body frame 2 is suppressed.

  Here, the reaction force of the spring 43 received by the O-ring 41 via the movable ring 40 increases as the pressing force of the drill against the work material increases and the compression of the spring 43 proceeds. The amount of elastic deformation in the axial direction increases. For this reason, the contact of the O-ring 41, which is a line contact with the fixed ring 39 and the movable ring 40 in an unloaded state, becomes a surface contact with an increase in the pressing force against the work material of the drill, and the contact area thereof Becomes larger.

  Accordingly, the pressing force of the drill against the work material is further increased, and the O-ring 41 is pressed with a strong force by the movable ring 40 as shown in FIG. However, in the range where the pressing force is 400 N or less, the support member 38 avoids metal contact with the fixed ring 39 of the movable ring 40 and a predetermined gap is secured between the two, so that the second ratchet 35 The vibration is effectively absorbed by the elastic deformation of the O-ring 41, and the propagation of vibration to the main body frame 2 is suppressed. As a result, even when a large pressing force is applied to the main body frame 2, it is possible to suppress the propagation of vibrations to the main body frame 2 to reduce the operator's discomfort and fatigue. Can be achieved.

It is a fracture side view of the vibration drill concerning the present invention. It is a fracture | rupture side view of the front-end | tip principal part which shows the state at the time of the drill mode of the vibration drill which concerns on this invention. FIG. 3 is an enlarged detail view of a main part of FIG. 2. It is a fracture | rupture side view of the front-end | tip principal part which shows the state at the time of the vibration drill mode of the vibration drill which concerns on this invention. It is a fracture | rupture side view of the front-end | tip principal part which shows the state at the time of the vibration drill mode of the vibration drill which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vibrating drill 2 Main body frame 3 Housing 4 Fan casing 5 Intermediate cover 6 Gear cover 7 Motor 8 Electric cord 9 Trigger switch 10 Output shaft (motor shaft)
DESCRIPTION OF SYMBOLS 11, 12 Bearing 13 Pinion gear 14 Cooling fan 15 Intake port 16 Exhaust port 17 Spindle 18 Intermediate shaft 19-22 Bearing 23-25 Gear 26 Drill chuck 27 Oil seal 28, 29 Gear 30 Guide shaft 31 Speed switching dial 32 Pin 33 Shifter 34 First ratchet 34a First ratchet claw 35 Second ratchet 35a Second ratchet claw 36 Spring 37 Sleeve 38 Support member 39 Fixed ring 40 Movable ring 41 O-ring (elastic member)
42 Snap ring 43 Spring 44 Pin 44a Recess 45 Operation mode switch 46 Ball

Claims (2)

A motor as a drive source;
A spindle driven to rotate by the motor and movable in the axial direction;
A first ratchet bound on the spindle;
A second ratchet that has a pawl that can be engaged with the pawl of the first ratchet, and is non-rotatable and movable in the axial direction;
A spring for urging the second ratchet toward the first ratchet;
A body frame housing the motor, spindle, first ratchet, second ratchet and spring;
In a vibration drill comprising
The fixing member fixed to the body frame with a movable member for supporting the anti-second ratchet side end of the spring provided to be movable in the axial direction in the body frame body in a counter second ratchet side of the movable member provided further provided an elastic member that contact area, and increases the compression progresses of the spring by the axial movement of the second ratchet between said movable member and said fixed member, said movable member side from the second ratchet a cylindrical portion extending provided, the movable member side end portion of the tubular portion into contact with said movable member thereby elastically deforming the elastic member through the movable member when a large pressing force to the body frame is applied The vibration drill is characterized in that the vibration of the second ratchet is absorbed by elastic deformation of the elastic member. A motor as a drive source;
A spindle driven to rotate by the motor and movable in the axial direction;
A first ratchet bound on the spindle;
A second ratchet that has a pawl that can be engaged with the pawl of the first ratchet, and is non-rotatable and movable in the axial direction;
A spring for urging the second ratchet toward the first ratchet;
A body frame housing the motor, spindle, first ratchet, second ratchet and spring;
In a vibration drill comprising
The second ratchet has a cylindrical shape and is provided with an inner cylinder part and an outer cylinder part that extend rearward along the axial direction of the spindle, and the second ratchet is slidable in the axial direction. The spring is provided between the inner tube portion and the outer tube portion of the second ratchet, and the movable member inserted through the outer periphery of the inner tube portion of the second ratchet is A second ratchet is provided so as to be able to move along the outer periphery of the inner cylinder part, and is attached to the main body frame so as not to slide, and a fixing member inserted through the outer periphery of the inner cylinder part of the second ratchet. Provided behind the movable member, an elastic member is interposed between the movable member and the fixed member, the spring is positioned between the second ratchet and the movable member, and the drill is pressed against the work material in front Impact drill, characterized in that as the by deforming the elastic member when the second ratchet and the movable member is retracted to prevent the contact of the fixed member and the movable member.

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