EP2646200A1

EP2646200A1 - Hammer percussion mechanism

Info

Publication number: EP2646200A1
Application number: EP11768039.7A
Authority: EP
Inventors: Joachim Hecht
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2010-11-29
Filing date: 2011-10-14
Publication date: 2013-10-09
Also published as: WO2012072326A1; DE102010062104A1

Abstract

The invention proceeds from a hammer percussion mechanism having at least one percussion drive unit (12a-c), a striker (14a-c) and a first rocker arm (16a-c) which is provided to drive the striker (14a-c). It is proposed that the hammer percussion mechanism has at least a second rocker arm (18a-c) which is functionally arranged between the first rocker arm (16a-c) and the percussion drive unit (12a-c).

Description

Description hammer blower

State of the art

The invention relates to a hammer blower according to the preamble of claim 1.

There has already been proposed a hammer blower with at least one impact drive unit, a racket and a first rocker arm intended to drive the racket.

Disclosure of the invention

The invention relates to a hammer blower with at least one impact drive unit, a racket and a first rocker arm, which is intended to drive the racket.

It is proposed that the hammer impact mechanism has at least one second rocker arm, which is operatively arranged between the first rocker arm and the impact drive unit. A "percussion drive unit" is to be understood in particular as meaning a device which is intended to translate a rotational movement into a preferably sinusoidal movement along a path that drives the racket Preferably, the percussion drive unit has a swash bearing, but particularly preferably an eccentric element The term "racket" is to be understood as meaning a means of the hammer impact mechanism which is intended to be accelerated in particular in a translatory manner during operation by the impact drive unit and which has a pulse recorded during the acceleration as a hammer. impulse in the direction of an insert tool. A "rocker arm" should in particular be understood to mean a device which is mounted such that it can move about a pivot axis and which is provided to deliver a power absorbed at a first coupling region to a second coupling region be understood. In particular, the term "driving" is intended to mean that the first rocker arm acts on the racket in a force dependent on the power that accelerates the racket in at least one operating condition in at least one direction Impact drive unit arranged "should be understood in particular that the impact drive unit transmits power in at least one operating state to the second rocker arm and that the second rocker arm transmits at least a majority of the power to the first rocker arm, which thus advantageously drives the racket. A "majority" should be understood as meaning at least 50%, advantageously at least 75%, particularly advantageously at least 90% Preferably, the first rocker arm and the second rocker arm are movably mounted about different and advantageously parallel pivot axes A space-saving, lightweight and low-vibration impact drive unit an effective impact pulse can be achieved.

In a further embodiment, it is proposed that the second rocker arm has a first lever arm and a second lever arm of different lengths to the first lever arm, whereby a particularly advantageous impact generation with only a few vibrations is structurally simple. Under a

"Lever arm" is to be understood in particular as meaning a path perpendicular to the pivot axis, between the pivot axis and a coupling region of the rocker arm, on which the force dependent on the power acts on the rocker arm. that the coupling region of the first rocker arm and the coupling region of the second rocker arm on the route are at different distances from the pivot axis. Preferably, the pivot axis of the second rocker arm is arranged closer to the coupling region for coupling to the impact drive unit than to the coupling region for coupling to the first rocker arm. Furthermore, it is proposed that the hammer impact mechanism comprises at least one gear stage, which is arranged at least partially in the axial direction between the impact drive unit and the racket, whereby a particularly small space requirement can be achieved. A "gear stage" is to be understood in particular a device which is intended to a

To translate the input speed to an output speed different from the input speed. Preferably, the gear stage is designed as a planetary gear stage. A "planetary gear stage" should be understood to mean, in particular, a unit having at least one sun gear, a ring gear, a planet carrier and at least one planet gear guided by the planet carrier on a circular path around the sun gear Alternatively, the gear stage could be designed as a spur gear stage In particular, "arranged in the axial direction between the impact drive unit and the racket" is to be understood in this context that the gear stage lies at least partially on a straight line which is aligned parallel to an axis of rotation of the percussion drive unit and / or advantageously parallel to a direction of impact, and which cuts the percussion drive unit and the racket in at least one area. It is also proposed that the hammer impact mechanism has a spindle blocking, which is arranged at least partially in the axial direction between the impact drive unit and the racket, which structurally simple, a particularly space-saving design is possible. A "spindle lock" is to be understood in particular to mean a device which, in at least one operating state, preferably when an operator applies a force to a tool chuck, prevents rotation of at least the tool chuck. that at least one of the rocker arms is resilient, whereby low vibrations and high impact energy can be achieved, in particular, the term "spring-loaded" means that the rocker arms together have a spring constant of between 100 N / m between a coupling region to the impact drive unit and a coupling region to the beater. mm and 10 N / mm. Preferably, the rocker arms together have a spring constant between 50 N / mm and 20 N / mm. Furthermore, it is proposed that the hammer impact mechanism has a tool chuck drive shaft, which supports the racket movably in the direction of impact in at least one operating state, whereby a particularly small installation space requirement can be achieved. A "tool chuck drive shaft" is to be understood in particular as meaning a shaft which transmits rotational movement from a gear, in particular a planetary gear, in the direction of a tool chuck during a drilling and / or percussion drilling operation Preferably, the chuck drive shaft extends in the direction of impact over at least 40 mm The tool chuck drive shaft and the tool chuck have the same speed during a drilling and / or percussion drilling operation, in particular a direction which runs parallel to an axis of rotation of the tool chuck and that of the stick in the direction of directed to the tool chuck. Preferably, the direction of impact is aligned parallel to a rotational axis of the tool chuck drive shaft. In particular, the phrase "movably support" is to be understood to mean that the tool chuck drive shaft has a bearing surface which, in at least one operating state, transmits bearing forces perpendicular to the direction of impact to the racquet.

In an advantageous embodiment of the invention it is proposed that the tool chuck drive shaft at least partially penetrates the racket, whereby a particularly space-saving design is structurally simple. In particular, the phrase "at least partially penetrating" is to be understood as meaning that the racket surrounds the tool chuck drive shaft by more than 270 degrees, advantageously by 360 degrees, on at least one plane, which is advantageously aligned perpendicular to the direction of impact Bat in a direction perpendicular to the axis of rotation of the tool chuck drive shaft positively secured to the tool chuck drive shaft, that is movably mounted in the direction of the axis of rotation.

It is also proposed that the hammer percussion includes a tool chuck and an anvil with a coupling means which is provided for transmitting a rotational movement to the tool chuck, whereby a particularly compact and powerful hammer impact mechanism is structurally simple. In particular, the term "tool chuck" is intended to mean a tion, which is intended to an insert tool by a user, in particular without tools detachable, at least rotationally fixed to fix directly. A "striker" is to be understood as meaning, in particular, an element of the percussion mechanism which transmits the impact impulse from the striker in the direction of the inserting tool in a striking operation The striker preferably strikes the inserting tool in at least one operating condition Dust through the tool chuck into the hammer impact mechanism A "coupling means" is to be understood in particular as meaning a means which is intended to transmit movement from one component to another component, at least by means of positive engagement. In particular, the coupling means is designed as a coupling that appears meaningful to a person skilled in the art, but advantageously a jaw coupling and / or a toothing. Advantageously, the coupling means has a plurality of positive locking elements and a region connecting the interlocking elements.

Furthermore, a hand tool with a hammer impact mechanism according to the invention is proposed. In this context, a "hand tool" is to be understood as meaning, in particular, a hand tool that appears appropriate to a person skilled in the art, but preferably a drill, a rotary hammer, a drill, a drill bit and / or a percussion hammer That is, in particular, the hand tool has a coupling means, which is provided to supply a drive motor of the hand tool from a connected to the coupling means hand tool battery with an electrical energy.

drawing

Further advantages emerge from the following description of the drawing. In the drawing, three embodiments of the invention are shown. The drawing, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into meaningful further combinations. Show it:

Fig. 1 is a schematically illustrated section of an inventive

Hammer impact mechanism with a first and a second rocker arm,

2 shows a part of the hammer impact mechanism of Figure 1 in a perspective view,

3 shows the part of the hammer impact mechanism of Figure 1 in a further perspective view,

4 shows a variant of the second rocker arm of Figure 1 in a perspective view,

Fig. 5 shows a second embodiment of the hammer impact mechanism according to the invention of Figure 1 and

6 shows a third exemplary embodiment of the hammer impact mechanism according to the invention from FIG. 1.

Description of the embodiments

Figures 1, 2 and 3 show a hammer mechanism 10a of a hand tool, not shown, which is designed as a battery-powered Schraubschlagbohrmaschine. The hammer mechanism 10a has a percussion drive unit 12a, a racket 14a, a first rocker arm 16a and a second rocker arm 18a. The impact drive unit 12a comprises an eccentric element 38a, an eccentric sleeve 40a and a sleeve bearing 42a. The eccentric element 38a is rotationally driveable connected to a gear 44a of the hammer mechanism 10a. The sleeve bearing 42a rotatably supports the eccentric sleeve 40a on the eccentric element 38a. The eccentric sleeve 40a is movable in an eccentric direction 46a and mounted pivotable by less than 45 degrees in a housing, not shown, of the hand tool. In an impact mode, the eccentric element 38a drives the eccentric sleeve 40a in the eccentric direction 46a in a sinusoidally moved manner.

The second rocker arm 18a is operatively disposed between the impact drive unit 12a and the first rocker arm 16a. The eccentric sleeve 40a of the impact drive unit 12a defines a recess 48a. The recess 48a penetrates the eccentric sleeve 40a perpendicular to the eccentric 46a. The second rocker arm 18a passes through the recess 48a. As a result, the second rocker arm 18a is driven to pivot about a pivot axis 50a in a hammering and percussion drilling operation. The pivot axis 50a is aligned perpendicular to the eccentric direction 46a and perpendicular to an axial direction 26a of the eccentric element 38a. The second rocker arm 18a has a first lever arm 20a and a second lever arm 22a. In this embodiment, the lever arms 20a, 22a have the same length. But they could also, as described in the embodiments of Figures 5 and 6, be of different lengths. A coupling region 52a of the first lever arm 20a is arranged in the recess 48a of the eccentric sleeve 40a. A coupling region 54a of the second lever arm 22a engages around a part of the first rocker arm 16a. For this purpose, the coupling region 54a of the second lever arm 22a defines a recess 56a.

The first rocker arm 16a is also pivotally mounted about a pivot axis 58a. The pivot axis 58a is aligned perpendicular to the eccentric direction 46a and perpendicular to the axial direction 26a of the eccentric element 38a. The first rocker arm 16a has a first lever arm 60a and a second lever arm 62a of different lengths from the first lever arm 60a. A coupling region 64a of the first lever arm 60a is disposed in the recess 56a of the second rocker arm 18a. As FIGS. 2 and 3 show, the second lever arm 62a has a coupling region 66a, which is designed as a part of an eyelet 68a of the second lever arm 62a facing away from the pivot axis 58a. In a percussion drilling operation, the first rocker arm 16a drives the club 14a.

For this purpose, the coupling region 66a engages in a recess 70a of the racket 14a. The recess 70a is arranged annularly on a lateral surface of the racket 14a. The first rocker arm 16a is resilient. Together, the first rocker arm 16a and the second rocker arm 18a have a spring constant of about 30 N / mm. FIG. 4 shows a variant of the second rocker arm

18a, which is also resilient.

The hammer blower 10a has a tool chuck drive shaft 30a, a tool chuck 32a and an anvil 34a. The tool chuck drive shaft 30a rotatably connects a part of the gear 44a and axially displaceable with the striker 34a. In addition, the tool chuck drive shaft 30 supports the racket 14a in the axial direction 26a movable. The racket 14a defines a recess 72a. This recess 72a is formed as a bore. The chuck drive shaft 30a penetrates the recess 72a bounded by the racket 14a in the axial direction 26a. The striker 34a has a coupling means 36a, which transmits a rotational movement of the striker 34a to the tool chuck 32a during operation. Thus, the tool chuck drive shaft 30a rotatably drives the tool chuck 32a over the striker 34a. The tool chuck 32a attached during a Schlagbohrbetrieb not shown in detail insert tool rotatably and axially displaceable.

The transmission 44a has first, second, third and fourth gear stages 74a, 76a, 78a and 24a. The four gear stages 74a, 76a, 78a and 24a are designed as planetary gear stages. The first gear stage 74a is driven by a rotor 80a of a drive motor of the hand tool. The first gear stage 74a translates a rotational speed of the rotor 80a to a lower rotational speed. The second gear stage 76a has a displaceable ring gear 82a. In an illustrated position, the displaceable ring gear 82a is rotatably mounted. It is rotatably connected to a planet carrier 84a of the first gear stage 74a. In this position, the second gear stage 76a does not translate the rotational speed, that is, an input rotational speed of the second gear stage 76a is equal to an output rotational speed of the second gear stage 76a. The slidable ring gear 82a can be slid toward the tool chuck 32a. Then, the slidable ring gear 82a is rotatably connected to a housing member 86a of the housing. In this position, the second gear 76a causes a reduction of the speed. Thus, the transmission 44a is switchable between two translations.

The third gear stage 78a further reduces the speed of the rotor 80a. A planetary gear carrier 88a of the third gear stage 78a is provided with a planet gear carrier 90a of the fourth gear stage 24a and with the tool chuck drive shaft

30a rotatably connected. A sun gear 92a of the fourth gear 24a is rotatably connected to the eccentric 38a. A ring gear 94a of the fourth gear stage 24a is detachably rotatably connected to the housing element 86a for impact deactivation. When pressing the insert tool in a Schlagbohrvorgang the tool chuck 32a is moved in the direction of the transmission 44a. A bridging element coupled to the tool chuck 32a Ment 96a thereby displaces the ring gear 94a of the fourth gear stage 24a so that it engages with the housing member 86a. Thus, the percussion drive unit 12a is activated by pressing the insert tool against a workpiece in a percussion drilling mode.

FIGS. 5 and 6 show two further exemplary embodiments of the invention. The following descriptions and the drawings are essentially limited to the differences between the exemplary embodiments, with reference in principle also to the drawings and / or the description of the other exemplary embodiments, in particular those relating to identically named components, in particular with regard to components having the same reference symbols Figures 1 to 4, can be referenced. To distinguish the embodiments, the letter a is the reference numerals of the embodiment in the figures 1 to 4 adjusted. In the exemplary embodiments of FIGS. 5 and 6, the letter a is replaced by the letters b and c.

FIG. 5 shows a hammer mechanism 10b with a percussion drive unit 12b, a club 14b, a first rocker arm 16b, a second rocker arm 18b, a spindle lock 28b and a transmission 44b. The first rocker arm 16b drives the racket 14b in a percussion drilling operation. The second rocker arm

18b is operatively disposed between the first rocker arm 16b and the percussion drive unit 12b. The first rocker arm 16b and the second rocker arm 18b each have a first lever arm 60b, 20b and a second lever arm 62b, 22b of different lengths from the first lever arm 20b, 60b. The first rocker arm 16b and the second rocker arm 18b are partially disposed in the axial direction 26b adjacent to the gearbox 44b and adjacent to the spindle lock 28b.

The transmission 44b has first, second and third gear stages 74b, 76b, 24b. The first gear stage 74b is driven by a rotor 80b of a drive motor. The first gear stage 74b translates a rotational speed of the rotor 80b of a drive motor to a lower rotational speed. The second gear stage 76b has a ring gear 82b which can be displaced in three positions. In an illustrated position, the slidable ring gear 82b is rotatably mounted. It is in the illustrated position with a planet carrier 98b of the second

Gear stage 76b and a drive gear 100b of the impact drive unit 12b rotatably connected. Thus, the second gear stage 76b in this operating state has no gear ratio and the impact drive unit 12b is active. The hammer blower 10b is in a percussion drilling mode.

The slidable ring gear 82b is slidable to a middle position for a drilling or screwing mode. In this case, the displaceable ring gear 82b is displaced from the position shown in the direction of the first gear stage 74b. In the middle position, a coupling between the slidable ring gear 82b and the drive gear 100b of the impact drive unit 12b is opened. As a result, the impact drive unit 12b is inactive. The slidable ring gear 82b is rotatable in the middle position and connected to the planet carrier 98b. Thus, the second gear stage 76b has no gear ratio in this operating state. The transmission 44b is in a drilling and screwing mode with a low reduction, that is, in a gear that allows a particularly high tool chuck speed.

The slidable ring gear 82b is displaceable in a third position for a larger reduction of the transmission 44b. In this case, the displaceable ring gear 82b is displaced further from the middle position in the direction of the first gear stage 74b. In the third position, a coupling between the slidable ring gear 82b and the planet gear carrier 98b of the second gear stage 76b is opened. In addition, the slidable ring gear 82b is rotatably engaged with a housing member 86b of a housing and rotatably connected. Thus, the second gear stage 76b is active in the third position. The transmission 44b is in a drilling and screwing mode with a high reduction, that is in a gear that allows a particularly low tool chuck speed.

The schematically illustrated spindle lock 28b and the third gear stage 24b are each partially arranged in the axial direction 26b between the impact drive unit 12b and the racket 14b. The spindle lock 28b is integrated in the third gear stage 24b. The third gear stage 24b provides a reduction and is connected to a chuck drive shaft 30b of the hammer mechanism 10b. FIG. 6 shows a hammer mechanism 10c with a percussion drive unit 12c, a club 14c, a first rocker arm 16c, a second rocker arm 18c a spindle lock 28c and a gear 44c. The first rocker arm 16c drives the club 14c in a percussion drilling operation. The second rocker arm 18c is operatively interposed between the first rocker arm 16c and the percussion drive unit 12c. The first rocker arm 16c and the second rocker arm 18c each have a first lever arm 60c, 20c and a second lever arm 62c, 22c of different lengths from the first lever arm 20c, 60c. The first rocker arm 16c and the second rocker arm 18c are partially disposed axially adjacent to the gear 44c and adjacent to the spindle lock 28c.

The transmission 44c has first, second and third gear stages 74c, 76c, 24c. The percussion drive unit 12c is arranged in the axial direction between the first gear stage 74c and the second gear stage 76c. A ring gear 82c is, as described in the embodiment of Figure 5, axially displaceable. It is also shown arranged in a percussion drilling mode. It is slidable to switch a screw or drilling mode towards a tool chuck 32c of the hammer impactor 10c.

Claims

claims

A hammer blower having at least one impact drive unit (12a-c), a beater (14a-c) and a first rocker arm (16a-c) provided to drive the beater (14a-c), characterized by at least one second rocker arm (18a-c) operatively disposed between the first rocker arm (16a-c) and the percussion drive unit (12a-c).

2. Hammer impact mechanism according to claim 1, characterized in that at least the second rocker arm (18b; 18c) has a first lever arm (20b; 20c) and a second lever arm (22b; 22c) of different length from the first lever arm (20b; 20c).

3. hammer impact mechanism according to claim 1 or 2, characterized by at least one gear stage (24b, 24c), which at least partially in the axial direction (26b, 26c) between the impact drive unit (12b, 12c) and the racket (14b, 14c) is arranged.

4. Hammer impact mechanism according to one of the preceding claims, characterized by a spindle lock (28b, 28c) which at least partially in the axial direction (26b, 26c) between the impact drive unit (12b, 12c) and the racket (14b, 14c) is arranged.

5. Hammer impact mechanism according to one of the preceding claims, characterized in that at least one of the rocker arms (16a-c, 18a-c) is resilient.

6. Hammer impact mechanism according to one of the preceding claims, characterized by a tool chuck drive shaft (30a-c) which supports the racket (14a-c) movable in at least one operating state in the axial direction (26a-c).

7. Hammer impact mechanism according to claim 6, characterized in that the tool chuck drive shaft (30a-c) at least partially penetrates the racket (14a-c).

8. Hammer impact mechanism according to one of the preceding claims, characterized by a tool chuck (32a-c) and an anvil (34a-c) having a coupling means (36a-c), which is provided for transmitting a rotational movement to the tool chuck (32a-c) ,

9. Hand tool with a hammer blower (10a-c) according to one of the preceding claims.