DE3300715C2 - Portable power operated rotary impact tool - Google Patents

Abstract

The rotary percussion tool contains a drive motor (1) which, via an intermediate part (2), transmits the rotation to a hammer (3) which comprises a spindle (4) which is aligned with the intermediate part (2) and which has lugs (5 and 5) on the outer surface 6), which correspond to the projections (8 and 9) on the inner surface (IO) of the racket (3), guides (11) for translational movement of the racket (3) in the plane perpendicular to the axis of rotation, and a housing (13) for accommodating the named assemblies of the tool. The guides (11) are eccentric with respect to the axis of rotation and are arranged directly on the intermediate part (2) which transmits the rotation to the racket (3).

Description

1.5. the hammer part (3), which is displaceably guided transversely to the axis of rotation (12), in at least one guide (11: 38; 42) is performed. that at a distance from a surface laid by the axis of rotation (12) (Middle surface between the guide surfaces 21, 22: 31,32; 44,45).

2. Rotary percussion tool according to claim 1, characterized in that the guides (11) flat to each other have parallel guide surfaces (21, 22).

3. Rotary impact tool according to claim 1, characterized in that the guides (11) are curved Have surfaces (26,27) whose centers of curvature (23) lie on a common line.

4. Rotary impact tool according to claims 1, 2 or 3, characterized in that the coupling and Control part (2) is designed in the form of a disc (25).

5. Rotary impact tool according to claim 4, characterized in that the guides (11) in the form two curved surfaces (26, 27) are carried out on the peripheral surface (28) of the disc (25) and on the end face (29) of the hammer part (3) there is a groove (30) in which the disc (25) slides is led.

6. rotary percussion tool according to claim 4, characterized in that the guides (11) in the form of a .Front approach (33) are carried out, which in a groove (34) on the end face (29) of the hammer part s (3) is guided in a sliding manner.

7. rotary percussion tool according to claim 5 or 6, characterized by a centering disc (35), which on the front face (36) of the ham-

mteils (3) is arranged coaxially to the disc (2) and has guides (38), soft the guides (11) of the coupling and control part (2) correspond, and that both end faces (29, 36) of the Hammertcils (3) are designed in the same way.

8. Rotary impact tool according to claims 1, 2 or 3, characterized in that the coupling and Control part (2) is designed in the form of a ferrule (41) which includes the hammer part (3) and which Guides (11) represent a continuous groove (42), wherein on the outer surface of the hammer part (3) two flats (44, 45) are made with which it is slidably guided in the groove (42).

9. rotary impact tool according to claims I to 8, characterized in that the spindle (4) the Coupling and control part (2) extends through and is mounted at both ends (16, 46) in the housing (13), on the outer surface of the coupling and control part (2) a rotary coupling (49) with the power drive (1) is provided.

10. Rotary impact tool according to claim 9, characterized in that the rotary coupling (49) in In the form of a bevel gear ring (50), which is seated with a on the shaft of the power drive (1) Bevel gear (51) meshes, the axis of which runs within an angle to the axis of the spindle (4).

11. Rotary impact tool according to claim 9, characterized in that the rotary coupling (49) a pulley (53), which via a belt (54) with one on the while of the power drive (1) seated pulley (55) is connected, the axis of which is parallel to the axis of the spindle (4) runs.

12. Rotary impact tool according to claim 9, characterized in that the rotary coupling (49) has a spur gear rim (56) which is connected to a spur gear seated on the shaft of the drive motor (1) (57) meshes, the axis of which runs parallel to the axis of the spindle (4).

13. Rotary impact tool according to claims 9 to 12, characterized by one executed in the spindle (4) central threaded hole (58) in which a screw (59) with a longitudinally extending Feather keyway (60) is arranged in which a keyway (61) secured in the housing (13) engages.

The invention relates to a portable power-driven rotary percussion tool according to the generic term of claim 1 as it is, for. B. when tightening and loosening screw connections or thread cutting is used, but also where workpieces have to be clamped or moved with great force. With rotary impact tools, continuous starting rotary movements of the drive motor

boriodic beats derived in such a way that a dated Motor accelerated hammer hammer strikes a part of the anvil connected to the working organ, whereby forces or moments can be achieved on the spindle, which the forces or moments on the drive motor shaft

b5 exceed Ie by 400 to 50 times. this makes possible the creation of small size and small mass cave excavation tools. Advantageously isl also that there is no moment of reaction that affects the

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Hands of the worker is transferred.

From US-PS 27 18 803 a rotary impact tool known, the drive motor of which the rotary movement via a coupling part on a spindle encompassing Hammer part transfers. The spindle is coaxial with the coupling part and is supported at one end on this. The other end of the spindle is mounted in the housing. The spindle has on the outer surface Längsa.isätzc to cooperate with those corresponding approaches on the inner surface of the hammer part. The hammer part can perform translational movements on guides at right angles to the axis of rotation.

The coupling part sits directly on the shaft of the drive motor and has a fork-shaped driver on, which is in engagement with an approach on one of the end faces of the hammer part and over this approach transfers the rotation to the hammer part. The translational movement of the hammer part across the axis of rotation takes place in this construction about an axis on which the hammer part is arranged such that it can commute. This axis is fixed in a clamp which includes the hammer part. When rotating the Hammer part hit the impact approaches on its inner surface periodically, namely after each revolution against the longitudinal attachments on the outer surface of the spindle. Come by a pendulum motion of the hammer part then the impact approaches out of engagement with the spindle approaches.

In this known training is to translate Movement of the hammer part a variety of parts (coupling part, clamp, axis) what is necessary complicates the construction. In addition, the fork-shaped driver of the coupling part touches the llammertcil forehead base on one line, which is why the Impact execution along this line high surface pressures occur, which lead to notches on the Surface of the fork-shaped driver, for wedging the hammer part and causing the tool to fail to lead.

The operational reliability of the tool is also impaired by the fact that one of the spindle bearings is not rigid, but the spindle is supported by the coupling part on the shaft of the drive motor. this results in increased wear of the hammer and spindle attachments and creates additional dynamic ones Stresses on the motor shaft.

The same applies to a rotary impact tool known from US-PS 30 72 232, of which the present one Invention proceeds and the features of which are mentioned in the preamble of claim 1. This tool is of largely the same design as the one considered above; the main difference is in that a rectangular opening is made in the ferrule, in which a corresponding in longitudinal section rectangular shape having hammer part is performed. True, this tool is simpler and more reliable than that considered at the outset, but are also here to enable the translatory hammer part movement a plurality of parts necessary.

In addition, the fork-shaped driver of the coupling part comes with the Siirnansat / Hammc-i part also here on a line interacting what the result in high surface pressures with the disadvantages described.

Finally, one of the spindle ends is also supported here Via the coupling part on the shaft of the drive motor, so that the dynamic loads act on the motor and the operational reliability of the tool is reduced.

The invention is based on the object of a rotary impact tool to create at riem the control of the translatory transverse movement of the hammer part aui the simplest way succeeds and thereby a high operational reliability and simple design is achieved.

This object is achieved according to the invention by the im characterizing part of claim 1 specified features solved. Appropriate training ίο of the invention emerge from the subclaims.

The invention is illustrated below through the description of exemplary embodiments with reference to the enclosed Drawings explained further. It shows

F i g. 1 is a partially sectioned side view of the tool;

Fig. 2 is an axonometric exploded view of the rotary impact direction of the tool:

Fig. 3 shows the section along the line 1-1 of Fig. I, which the mutual position of the elements of the rotary impact device at the moment the impact is performed represents;

Fig. 4 the section along the line l-l at the moment, when the face and the striking face disengage;

5 shows the section along the line I-I after a rotation the hammer part by 180 'compared to the position shown in FIG. 3;

Fig. 6 shows the section along the line 1-1 just before the Impact execution;

7 shows an axonometric exploded view of the rotary impact device of the tool in another Embodiment of the guide;

8 shows a partial section of a tool having a centering disk;

F i g. 9 is a partial section of a tool in which the Coupling and control part is designed as a clamp;

Fi g. 10 shows the section along the line X-X from FIG. 9:

F i g. 11 is a partial section of a tool with a Angle drive;

12 shows a partial section of a tool with a Belt drive;

13 shows a partial section of a tool with a Drive via a pair of spur gears.

The rotary percussion tool according to FIGS. 1 to 6 has a Power drive 1 accommodated in a housing 13, usually an electric or pneumatic one Drive motor, which transmits the rotation to a hammer part 3 via a coupling and control part 2, which comprises the anvil part 4 'of a screwdriver spindle 4 which is mounted coaxially to the coupling and control part 2 is.

On the outer surface 7 of the anvil part 4 'impact surfaces 5 and 6 are formed with striking surfaces 8 and 9 cooperate on the inner surface 10 of the hammer part 3.

Guides 11 are provided for the translatory movement of the hammer part 3 at right angles to the axis of rotation 12. These are arranged at a distance from a plane containing the axis of rotation 12 and are immediate formed on the coupling and control part 2, which transmits the rotation to the Hammertüil 3.

[>; s clutch and control part 2 is immediately on the Abuiebswelle 14 of the power drive 1 and for example via a key 15 with her gckop-6: pelt. The spindle 4 is mounted in the vicinity of its tool-side end 16 in a bearing 17 in the housing 13, while its other end 18 engages in a bearing 19 in the coupling and control part 2 and on this on the

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Shaft 14 of the power drive 1 is supported. At the end of 16 the Spindle 4 is a shaft 20 for receiving the working member (not shown).

In the training according to FIG. 2, the coupling and control part 2 has the shape of a disk 25 with a Hub bore for placing on the output shaft 14 and with a guide 11 in the form of end projections 33, whose guide surfaces 21 and 22 are flat and run parallel to one another. These engage in a straight groove 34 on the forehead 29 of the hammer part 3.

In the embodiment of the tool according to FIG. 7, the coupling and control part 2 is also designed in the form of a disk 25 and the guides 11 are curved surfaces 26 and 27 formed on the circumference 28, which are diametrically opposed to one another and have a common center of curvature 23 on the axis of symmetry 24 of the coupling and control part 2 . The hammer part 3 has a groove 30 on the end face 29. the edges of which represent guide surfaces 31, 32 which cooperate in a sliding manner with the curved surfaces 26, 27 so that the coupling and control part 2 and the hammer part 3 can perform rocking movements around the common center of curvature 23 relative to one another. Correspondingly, the radii of curvature are also equal to one another.

With this design it would also be possible for the guide surfaces 31, 32 of the hammer part 3 and the peripheral surfaces of the coupling and control part cooperating with them to lie in parallel planes, ie the groove 30 on the end face 29 of the hammer part 3 is straight.

It goes without saying that the groove 34 and 30 could also be carried out on the end face 25 'of the disc 25 of the coupling and control part 2 and the gliding tend in these grooves engaging projections on the hammer part 3. It is also understood that also in the Ausbil dung according F i g. 2 a curved guide 11 could be realized.

At the ir. F i ^σ . 8 ^σ £ ζεί ^α ΐ £ η. Training, the work tool also has a centering disc 35 on the front face 36 of the hammer part 3 . On the end face 37 of the centering disk 35 there are guides 38 which are identical to the guides 11 of the disk 25 . ie the end faces 29 and 36 are identical . Accordingly, a groove 39 is also made on the front face of the hammer part 3, which is flat. which of the groove 34 on its rear end face 29 is identical. The guides 38 in the form of an end projection 40 engage in the groove 39, just as the guides 11 in the form of an end projection 33 engage in the groove 34 in the manner described.

Fig. 9 and! 0 show an embodiment of the tool, in which the coupling and control part 2 as a Zv. inge 41 is executed. soft the hammer part 3 includes. The guides are formed by the border of a continuous groove 42 in which the hammered! 3 is guided in a sliding manner. For this purpose, it has two Abfiachupgen 44 and 45 on its outer surface 43.

Fig. !! shows an embodiment of the tool in which the spindle 4 extends through the coupling and control part 2 and is mounted with its two ends 16 and 46 in bearings 17 and 47 of the housing 13. At both ends 16 and 46 of the spindle 4, shafts 20 and 48 for attaching a working member are formed.

On the circumferential surface of the clutch and control valve 2 is! A bevel toothing 50 designed as a rotary coupling 49 with the drive motor 1, which meshes with a bevel gear 51 on the shaft 14 of the drive motor 1. The bevel gear 51 is rotatably connected to the shaft 14 by means of a feather key 15. The axis 52 of the drive motor 1 runs at right angles to the axis 12 of the spindle 4. The axes 52 and 12 could also form any other angle with one another.

In Fig. 12, the rotary coupling 49 is a belt drive with a pulley 53 driven by a belt 54 with a pulley 55 on the shaft 14 of the motor 1 is connected. The axis 52 of the motor 1 lies parallel to the axis 12 of the spindle 4.

Fig. 13 shows a rotary coupling 49 in the form of a Spur gear rim 56, which is in engagement with a spur gear 57 on the shaft 14 of the drive motor 1, whose Axis 52 is parallel to axis 12 of spindle 4.

11, 12 and 13, the coupling and control part 2 is designed in the form of the disk 25; it goes without saying that the shape of a ferrule was also chosen here could be.

Fig. 13 also shows a design for using the tool as a screw jack. To do this, in the spindle 4 executed a threaded hole 58, in which a screw 59 with a longitudinal groove 60 for a Key 61 is used. The feather key 61 is secured in the cover 62 of the housing 13 and causes a Axially displaceable bearing that is non-rotatable with respect to the housing. The spindle 4 is in the housing 13 by means of a Plain bearing 63 and a thrust bearing 64, which is installed in the cover 65 of the housing 13, stored.

The operation of the rotary impact tool described is as follows:

A working member is pushed onto the shaft 20 of the spindle 4. The power drive 1 is then switched on and its rotary movement is controlled by the shaft 14 Transferred via the coupling and control part 2 to the hammer part 3 by means of the guides 11. In the Rotation of the rotary impact device leads to periodic impacts of a striking surface against the associated impact surface, e.g. B. at the in F i g. 3 to 6 shown clockwise rotation strikes the striking surface 8 periodically on the impact surface 5. Here the kinetic energy stored during the previous rotational acceleration of the hammer part 3 is transferred to the spindle 4 and this rotates with it the working organ at a certain angle, after which it stops. The process is as follows:

Immediately after the execution of an impact, the hammer part 3 and are initially also located with the spindle 4 the coupling and control part 2 in the in F i g. 3 position shown still. Since the drive motor is switched on remains, its torque continues to act via the clutch and control part 2 on the hammer part 3. When looking at FIG. 3 thus presses the guide surface 21 of the left-hand end extension 33 upwards onto the wall of the hammer part groove 34 which cooperates with it, see above that the striking surface 8 of the hammer part 3 is pressed against the striking surface 5 of the anvil part 4 'of the spindle 4. The resultant of these two on the Forces acting on the hammer part is when considering FIG. 3 directed approximately to the 10 o'clock position and therefore has a component indicated by an arrow along the guide 11, which the hammer part 3 on this Guide 11 can slide to the left relative to the coupling and control part 2 until, as can be seen in Figure 4, the Striking surface 8 comes out of engagement with the striking surface 5, with the inner surface 10 of the hymn part 3 in the area of the striking surface 9 on the outer surface 7

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of the anvil part 4 'applies.

Now a new spin acceleration of the clutch and control part 2 begin together with the hammer part 3, this kinetic energy for the saves the next beat. During this rotation, the inner surface 10 of the hammer part 3 slides on the Outer surface 7 of larger diameter of the anvil part 4 'in the area of its impact surface 5. so that the Hammer part 3, which compared to the coupling and control part 2 is only given by the guide 11 Has degree of freedom on this guide in the direction of the arrow in the F i g showing an intermediate position. 5 slides. The striking surface 9 moves away from the outer surface 7 of smaller diameter of the anvil part 4 ', while the face 8 approaches this surface. The adjustment of the hammer part 3 on the guides 11 lasts until the striking surface 8 is the outer surface 7 smaller diameter of the anvil part 4 'achieved what happens at the moment when the The striking surface 9 slides over the striking surface 5, that is to say in one of the positions shown in FIG. 5 and 6 intermediate layer to think about. From this point on, the clutch and control part 2 and the rotate Hammer part 3 further without changing their mutual position.

Shortly before the striking surface 8 strikes the striking surface 5, the striking surface 9 slides over the striking surface 6 away, and then it comes to execution in the position according to Fig. 3. Now the Repeat cycle.

When the power drive 1 and thus the rotary percussion device 2, 3, 4 rotate in the opposite direction The processes proceed analogously (counterclockwise), whereby it is evident that they are periodic Strikes the striking surface 9 on the impact surface 6 comes.

It can be seen that the movement of the hammer part 3 in every rotational position by the guide 11 of the coupling and control part 2 and the interaction of its inner surface 10 with the outer surface 7 of the anvil part 4 'is given, a rotation and an adjustment in the direction perpendicular to the axis of rotation Level takes place. Only the few parts considered are required for this, and the type of tooling becomes simpler. In addition, the interaction between the parts always takes place on surfaces, which leads to a reduction the surface pressure is guaranteed.

In the execution of the guides 11 according to FIGS. 2 to 6 with flat guide surfaces parallel to one another 21, 22, the adjustment movement of the hammer part 3 takes place when the engagement between the striking surface 8 is released and the impact surface 5 on a straight line with respect to the coupling and control part 2. This embodiment the guides 11 is a particularly simple one.

When executing the guides 11 according to Fi g. 7 with curved surfaces 26, 27, which correspond to curved guide surfaces 31, 32 cooperate, the centers of curvature 23 of all these surfaces lie on a common line, the adjustment of the hammer part 3 takes place on the guides 11 on a curved path around the line of the centers of curvature 23. This makes the release the engagement between the striking surface 8 of the hammer part 3 and the striking surface 5 of the anvil part 4 'facilitated.

A reduction in the dynamic loads on the shaft 14 of the drive motor is made possible by the Providing a centering disk 35 according to FIG. 8. Im The hammer part 3 operates via the groove 39 on its front end face 36 and the one engaging therein Approach 40 of the centering disc 35 with this. so ■ j that the disk 25, the hammer part 3 and the centering disk Rotate 35 together. During the adjustment movements of the hammer part 3, the groove 34 slides on the Approaches 33 of the disc 25 and at the same time the groove 37 slides with its surfaces on the approach 40 of the

ίο centering washer 35. Since the lugs 33 and 40 and the Grooves 34 and 39 are identical, the centering disc 35 will rotate in the same way as the disc 25 of the coupling and control part 2 and the hammer part 3 is held and guided on both sides.

In the execution of the coupling and control part 2 in the form of the clamp 41 according to FIG. 9, 10, which includes the hammer part 3, the rotary movement is transmitted from the power drive 1 to the hammer part 3 via the continuous groove 42 made in the clamp 41. During the adjustment movement of the hammer part transversely to the axis of rotation, the flats 44 and 45 slide along the edges of the groove 42 and, after the impact, ensure that the engagement between the striking surfaces of the hammer part and the striking surfaces of the anvil part is released. Since the flattened areas 44 and 45 extend over the full length of the hammer part 3, a more precise alignment of the surfaces interacting during the impact can be achieved.
In the construction of the tool according to FIG. 11, the power drive 1 does not need to be reversible because the two directions of rotation are available at the two ends 20 and 48 of the spindle 4 and the working element can be attached to the required shaft end 20 or 48. In addition, the dynamic stresses arising during the impact execution are transmitted directly to the housing 13, so that the dynamic stresses on the motor are reduced. In this embodiment of the tool, the dimensions can also be significantly reduced.

If according to FIG. 11 as a rotary coupling 49 between the drive motor and the coupling and control part 2 a bevel gear ring 50 is used, the arrangement of the drive motor is at any angle to Axis of the spindle 4 possible, and it can, for. B. minimum height dimensions of the tool can be achieved.

If, according to FIG. 12, the rotary coupling 49 is implemented by means of a belt drive, then because of the favorable damping properties of the belt a further reduction of the dynamic stresses of the drive motor and thus an increased tool life.

The tool in the embodiment according to FIG. 13 with the central threaded hole 53 in the spindle 4 and the arrangement of the screw 59 in this bore serves as a hoist, for example as a screw jack. Here the drive motor 1 and the rotary percussion device 2, 3, 4 function as described above. With each impact pulse on the spindle 4, the latter rotates through a certain angle and the screw 59 rotates executes a translational movement in the direction of the axis of the spindle 4. During the translational movement of the screw 59, the keyway 60 slides along the key 61, which sits in the cover 65 and prevents it.

b5 that the screw 59 together with the spindle 4 turns. The change in direction of the translational movement of the screw 59 is caused by reversing the drive motor carried out. Through the transitory

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Movement of the working organ results in a significant expansion of the tool's scope of application.

In addition 5 sheets of drawings

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Jf 25

30th

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50

Claims (1)

33 OO 715 claims:!. Portable power-driven rotary impact tool, in particular impact wrench, consisting of 1.1. a tool housing (13) in which the rotary impact device (2, 3, 4) and the power drive (1) are mounted. 1.2. one protruding from the case Screwdriver spindle (4), which is non-rotatable with at least one radial impact surface (5. 6) having anvil part (4 ') of the impact device is connected, 1.3. a ring-shaped, the anvil part! with radial play and at least a more radial face (8, 9) enclosing, axially between end faces (4 ", 25 '; 37, 25') mounted and The hammer part (3) which is displaceably guided transversely to the axis of rotation (12) and its adjacent to the striking surfaces Inner surface (10) with an outer surface (7) of the anvil part (4 ') when controlling the In engagement position (impact position) interact, 1.4. one through the output shaft (14) of the power drive (1) drivable coupling and control part (2) with which the interacting during rotary impact Striking surfaces (8, 9) of the hammer part (3) and the striking surfaces (5, 6) of the anvil part (4 ') are controllable into a disengaged position after the impact, characterized in that