WO2011072917A1

WO2011072917A1 - Hand-operated reciprocating power saw, in particular jigsaw

Info

Publication number: WO2011072917A1
Application number: PCT/EP2010/065978
Authority: WO
Inventors: Florian Bantle; Tobias Brugger
Original assignee: Robert Bosch Gmbh
Priority date: 2009-12-17
Filing date: 2010-10-22
Publication date: 2011-06-23
Also published as: DE102009054809A1

Abstract

A hand-operated reciprocating power saw (1) has a saw blade (2), which performs an oscillating reciprocating movement and is driven by means of a motor-operated drive device (5). The drive device (5) comprises a rotatable hollow drive body (7), which encloses a pusher part (4), which holds the saw blade (2) and is movably mounted, wherein the hollow drive body (7) and the pusher part (4) interact via control means (17, 18, 19) in such a way that a rotating movement of the hollow drive body (7) is converted into a reciprocating movement of the pusher part (4).

Description

Description title

Hand-held lifting saw, especially jigsaw

The invention relates to a hand-held Hubsägemaschine, in particular a jigsaw, according to the preamble of claim 1.

State of the art

Such a hand-held, electric motor driven Hubsägemaschine is known from DE 10 2006 030 558 A1. The saw blade of the Hubsägemaschine is held on a lifting rod, which performs an oscillating lifting movement. The saw blade is supported on its rear side facing away from the feed direction via a support device which consists of a U-shaped, pivotally mounted on the housing of Hubsägemaschine holder and a support roller which is rotatably mounted in the holder and rests against the back of the saw blade. About the holder acting on the saw blade pendulum motion can be generated, which is superimposed on the oscillating stroke movement.

The drive of the saw blade receiving the lifting rod via a drive device which is usually arranged laterally of the lifting rod and the saw blade and over which the rotational movement of the drive motor is converted into the translational stroke movement. The lateral positioning can lead to a wobbling movement, if a balancing mass with 180 ° - phase shift is moved up and down to the lifting rod. This wobbling motion must be picked up by the user while guiding the Hubsägemaschine. A further disadvantage is that the positioning in the side region of the lifting rod restricts the possibilities of use, in particular with regard to further movements, which are impressed on the saw blade.

Disclosure of the invention The invention has for its object to perform with simple design measures a hand-held Hubsägemaschine so that the burden on the Hubsägemaschine leading person are reduced and at the same time a work result can be achieved with high accuracy.

This object is achieved with the features of claim 1. The dependent claims indicate expedient developments.

The hand-held Hubsägemaschine has a tool as a saw blade, which performs an oscillating stroke movement during operation of the Hubsägemaschine. The hand-held Hubsägemaschine is in particular a jigsaw. The Hubsägemaschine is equipped with a drive motor, in particular an electric drive motor whose drive movement is transmitted to the saw blade via a drive device. The motor movement is usually a rotational movement, wherein the rotational movement is converted into the oscillating, translational stroke movement of the saw blade via the drive device.

The drive device according to the invention comprises a rotatable drive hollow body which is barrel-shaped or sleeve-shaped and mounted parallel, preferably coaxially with the saw blade lifting axis. In the interior of the drive hollow body, a driver part is arranged displaceably, which holds the saw blade or a lifting blade receiving the saw blade. The drive hollow body is set by the drive motor of the Hubsägemaschine in a rotary motion, preferably in an oscillating rotational movement, wherein the rotational movement of the drive hollow body is transmitted via control means in the up and down movement of the driver hollow body entrained by the driver.

This is given on the one hand a compact design of the drive device. The drive hollow body engages around the driver part displaceably mounted in the interior of the drive hollow body, so that an at least approximately coaxial alignment of drive hollow body and driver part is provided. The motion conversion of the rotary motion of the drive hollow body in the lifting movement of the driver part can be realized via the control means in a simple, mechanical manner. The control means are designed, for example, as a control cam on the inner wall of the drive hollow body and as a drive cam on the driver part, which engages in the control cam. The control cam is preferably designed as a control groove, which is introduced into the inner wall of the drive hollow body. In principle, however, is also an embodiment of the control cam as over the inside of the drive hollow body projecting control wall, along which the drive cam is guided along. In addition, embodiments come into consideration, in which the control cam - either in the execution of a groove or in the embodiment as a projecting control wall - are arranged on the driver part and the cooperating cams on the drive ring gear, in particular on the inside of the drive ring gear. In addition, further embodiments are conceivable, in particular with regard to the positioning of the control means on the drive ring gear, which may for example also be arranged on the front side or possibly on the outside of the drive ring gear.

According to a preferred embodiment, the drive hollow body in addition to the driver part also surrounds a compensation mass part, which is also mounted displaceably and executes a stroke movement out of phase with the driver part in order to reduce the vibrations in the lifting saw machine. The compensating mass portion is driven by a further control means on the drive hollow body. In contrast to the prior art embodiment, the tumbling movements of the lifting saw machine are reduced, since the driver part, which receives the saw blade, and the compensating mass part, which exerts an opposite movement to the driver part, can be arranged at a small distance from each other. In particular, it is possible to position the driver part and the compensation mass part directly next to each other so that only minimal moments causing the tumbling motion can arise, the cause of which lies at a distance from the axes of movement of the driver part and the compensation mass part. At the same time a compact design is given, since both the driver part and the compensating mass part are mounted axially displaceable within the drive ring gear.

According to a further advantageous embodiment, both the driver part and the compensating mass part are each provided with a driving cam, which in the control cam engages the inner wall of the drive hollow body. In order to produce the opposite movement of driver part and compensating mass part, the drive cams are on diametrically opposite sides of the driver part or compensating mass part and engage in different sections of the control cam on the inside of the drive ring gear. In this case, both versions come into consideration, in which a common control cam is provided for both drive cam on the driver part and on the compensation mass part, as well as versions with two separate, individual control cams on the inside of the drive ring gear. The cams have an opposite course in order to produce the opposite stroke movement of driver part and compensating mass portion can. The control cams for the driver part and the compensating mass part have, in particular, an angle inclination relative to the axis of rotation of the drive hollow body on the inner wall of the drive ring gear in order to translate the rotational movement of the drive ring gear in the lifting movement directed vertically to the rotational plane. The cams for the driver part on the one hand and the compensating mass part on the other hand extend expediently each have a limited angular segment of, for example, a maximum of 180 ° on the inside of the drive ring gear and run in opposite directions inclined to achieve the desired opposite reciprocating motion. In the case of a common control cam for both drive cams on the driver part or on the compensation mass part, the respective driver cams move only over a partial section of the control curve, which can extend over a larger angular range, so that a sufficiently large cam section for both the driver part and for the compensating mass part is available.

According to yet another advantageous embodiment, it is provided that a lifting rod holding the saw blade is pivotally mounted on the driver part and the drive hollow body cooperates with a pendulum lifting device for generating a reciprocating motion superimposed on the lifting movement about the pivot axis of the lifting rod on the driver part. For this purpose, the drive hollow body is operatively coupled via pendulum stroke control means with the pendulum lifting device. The pendulum movement of the lifting rod takes place about the pivot axis which is perpendicular to the stroke axis. The pendulum stroke control means for generating the pendulum movement expediently comprise a pendulum stroke control cam, which is formed on the drive hollow body, and a Abtastnocken on a Pendelhubscheibe which acts on a pivoting unit, via which a transversely directed to the lifting pivot movement on the saw blade or on the lifting rod for generating the desired pendulum motion is transferable. Basically also comes a reverse embodiment, in which the pendulum stroke control cam is formed on the pendulum lifting disc and the Abtastnocken on the drive hollow body.

The pendulum stroke control cam is basically independent of the control curve over which the lifting movement is generated. According to a preferred embodiment, both control cams are formed on the drive hollow body, wherein the control cam for generating the lifting movement of the driver and optionally also the compensation mass portion advantageously on the inside of the drive ring gear and the pendulum stroke control cam are arranged on one of the end sides of the drive hollow body. The frontal positioning of the pendulum stroke control cam has the advantage that the pendulum lifting disc, to which the adjusting movement is transmitted, can be arranged directly adjacent to the axial end face of the hollow drive body and mounted coaxially therewith. The pendulum lifting disc surrounds in this embodiment, analogous to the drive hollow body, the driver part and possibly the compensating mass part.

The Pendelhubscheibe can, according to further expedient embodiment, relative to the pivoting unit, via which the pivoting or oscillating motion is transmitted to the saw blade or the lifting rod, are axially displaced, being actuated via the axial displacement of the pendulum lifting a Pendelhubstößel and also axially adjusted, which is mounted axially displaceable in the pivoting unit. The pendulum pushrod acts on a roller lever, which is pivotally mounted on the pivot unit, and pivots the roller lever in the direction of the saw blade.

It may be expedient to provide a Pendelhubwahlschalter to adjust the maximum allowable height of the pendulum stroke and thus also the swing of the pendulum motion over which the axial stroke of the Pendulum hub can be limited. The limitation of the stroke movement also has a limitation of the pendulum motion result.

According to yet another and advantageous embodiment, it is provided that the pivoting unit is rotatably mounted about the saw blade lifting axis or an axis parallel thereto. The rotatable mounting of the pivoting unit is in particular by up to 360 °, so that the pivoting unit relative to a housing of the hand-held Hubsägemaschine and based on the saw blade lifting axis can take any angular position. The rotation of the pivoting unit is preferably accompanied by a rotation of the driver part or of the saw blade, so that the saw blade can also assume any desired angular position. In this embodiment, the Hubsägemaschine has a total of three independent movement options or degrees of freedom: on the one hand, the oscillating lifting movement of the saw blade, on the other the pendulum motion and finally the rotational movement about the saw blade lifting axis. The rotation of the pivoting unit preferably takes place via its own drive device.

Further advantages and expedient embodiments can be taken from the further claims, the description of the figures and the drawings. Show it:

1 is a perspective view of a jigsaw running as a jigsaw saw, with a drive device comprising a hollow drive body, which encompasses both an axially displaceably mounted driver part and a phase-displaced movable compensation mass part and put both components in an oscillating stroke movement,

2 is a partial section through the saw blade lifting axis of the jigsaw,

3 is a drive hollow body in perspective detail view,

4 the drive hollow body in section,

5 shows the lifting mechanism of the drive device for generating the lifting movement of the driver part and the compensating mass part, 6 shows a pivot unit of the drive device, via which a pendulum stroke movement can be transmitted to the saw blade,

7 is a further sectional view of the drive hollow body with a view of a arranged on the front side pendulum stroke control cam,

8 a pendulum lifting disk, which is acted upon by the pendulum stroke control cam on the end face of the drive hollow body,

9 shows a section through the jigsaw with a representation of the transmission of motion on the pendulum lifting disk and further on a pendulum lifting tappet, shown in top dead center of the pendulum stroke,

Fig. 10 is a Fig. 9 corresponding representation, but shown at bottom dead center.

In the figures, the same components are provided with the same reference numerals.

In Fig. 1 and 2, designed as a jigsaw 1 hand-held Hubsägemaschine is shown, which is driven by an electric motor. The jigsaw 1 has a saw blade 2 as a tool, which is connected via a saw blade tensioning device 3 with a lifting rod 8 which is pivotally mounted on a driver part 4 via a pivot pin 9. The pivot axis of the pivot pin 9 is orthogonal to the saw blade lifting axis 6, which also represents the longitudinal axis of the saw blade and the lifting rod and the driver 4. The driver part 4 including the lifting rod 8, the saw blade tensioning device 3 and the saw blade 2 can perform an oscillating lifting movement along the saw blade lifting axis 6. This axial stroke movement can be superimposed on a rotary pendulum movement of the lifting rod 8 about the pivot pin 9.

The up and down movement of the driver 4 is generated by means of a drive device 5 comprising a barrel-shaped drive hollow body 7, which is arranged coaxially to the saw blade lifting axis 6 and the driver part 4 including the lifting rod 8 receives. The drive hollow body 7 has a substantially cylindrical inner cavity which serves to receive the driver part 4 and the lifting rod 8 and a compensating mass part 16. The drive hollow body 7 is mounted rotatably about the saw blade lifting axis 6 on the housing 10 of the jigsaw 1 and has on its outer casing a conical section which is provided with a toothing 7a, via which the drive movement of the electric drive motor of the jigsaw 1 on the Rotary movement of the drive hollow body 7 is transmitted. During operation of the jigsaw 1, the drive hollow body 7 expediently performs an oscillating rotary movement. The rotational movement is transmitted via a control cam 17 on the inside of the drive hollow body 7 (FIG. 4) and via driver cams 18 and 19, which are located on the driver part 4 and on the compensation mass part 16, into an opposite, axial stroke movement of driver part 4 and compensation mass part 16 ,

To generate the pendulum stroke movement about the axis of the pivot pin 9, the rotational movement of the drive hollow body 7 is also used, which has a Pendelhub- control cam 20 at its lower end as Pendelhubsteuermittel which arranged by a Abtastnocken 21 on the upper, facing end face of the coaxial with the drive hollow body 7 Pendulum hub 12 is tapped. The pendulum lifting plate 12 is mounted axially displaceable on the pivoting unit 1 1 and actuates a Pendelhubstößel 13, which performs the same axial adjusting movement as the pendulum lifting disc 12. The Pendelhubstößel 13 acts on a roller lever 14 which is pivotally mounted on the lower portion of the pivot unit 1 1, and pivots the roller lever 14 about its pivot on the pivot unit 1 1. The roller lever 14 carries on its the Pendelhubstößel 13 side facing a rotatably mounted roller 15th , which is in contact with the back of the saw blade 2. In an axial adjusting movement of the pendulum lifting disc 12 and the Pendelhubstößels 13 down the roller lever 14 is pivoted with the roller 15 in the transverse direction on the saw blade 2 and deflects the held on the lifting rod 8 saw blade 2, which is a pendulum motion to the

Swivel axis in the pivot pin 9 exerts.

To limit the pendulum stroke a Pendelhubwahlschalter 22 is pivotally mounted on the housing 10, which acts on a portion of the upper end of the Pendelhubscheibe so that the lifting movement of the Pendelhubscheibe 12 limited depending on the current position of Pendelhubwahlschalters 22 is. In this way, the deflection of the pendulum motion about the pivot axis of the pivot pin 9 is limited.

In FIGS. 3 and 4, the drive hollow body 7, which is designed as a ring gear, each shown in individual representation. The toothing 7a is located on the conical portion on the outer circumferential surface of the drive hollow body 7. FIG. 4 shows the control cam 17, which is introduced on the inside of the drive hollow body 7 as a control groove in the inner wall and a limited angular segment of for example 180 ° extends along the inside with an oblique, spiral-shaped course. The cam 17 thus has both a component in the axial direction and in the circumferential direction, so that the projecting into the control cam 17 cam cam is adjusted in a rotation of the drive ring gear about the axis 6 in the axial direction. Exactly one control cam 17, in which both drive cams 18 and 19 project on the driver part 4 or on the compensation mass part 16, is expediently located on the inner wall of the drive hollow body 7. The drive cams 18 and 19 are diametrically opposite each other and protrude into different, up or down and oppositely inclined portions of the control cam 17, so that rotation of the drive hollow body 7 causes an opposite lifting movement of the driver 4 and the compensating mass portion 16.

In Fig. 5, the lifting mechanism is shown in individual representation. The lifting mechanism comprises the driver part 4 with the lifting rod 8, the compensating mass part 16 and the pivoting unit 1 1, in which the driver part 4 with the lifting rod 8 and the compensating mass part 16 are guided axially displaceable. The guide is made by engaging guide ribs 25 and 26 on the driver part 4 and on the compensation mass part 16 in guide grooves 23 and 24 on the inside of a central recess in the pivot unit 1 first The guide grooves 23 and 24 are diametrically opposed to each other. Due to the guidance over the guide grooves and guide ribs, although an axial relative displacement of driver part 4 and compensating mass part 16 with respect to the pivoting unit 1 1 is possible, but no relative rotation.

The pivoting unit 1 1 is rotatably mounted on the housing of the jigsaw about the axis 6. During a rotational movement of the pivoting unit 1 1 due to the existing in the circumferential direction positive connection and the driver part 4 and the Compensation mass portion 16 is rotated about the axis 6 relative to the housing of the jigsaw. The rotation range is preferably 360 °. In this way, the position of the saw blade relative to the housing can be rotated in any angular position.

The rotational movement of the pivoting unit 1 1 is performed via a separately running drive device, which preferably has its own setting unit, but optionally can also be derived from the drive movement of the electric drive motor. The pivoting unit 1 1 is provided at its periphery with a toothing 1 1 a, which meshes with a drive wheel, via which the current rotational position of the pivoting unit 1 1 is adjustable.

The pivoting unit 1 1 is also provided with a form-fitting receptacle 1 1 b (FIGS. 5, 6 and 8), which serves for receiving and supporting the pendulum lifting disk 12 in a form-locking manner in the circumferential direction. Due to the non-rotationally symmetrical cross section of the positive locking receptacle 1 1 b and a complementary executed recess in the pendulum hub 12 Pendelhubscheibe is positively connected in the circumferential direction with the pivot unit 1 1 and thus exerts during a rotational movement of the pivot unit 1 1, the same rotational movement. Axial, the pendulum lifting plate 12 but can be adjusted relative to the pivot unit 1 1.

In Fig. 7 the drive hollow body 7 is shown again in detail. Evident is at the lower axial end side of the pendulum stroke control cam 20 which is scanned by the sampling cam 21 shown in Fig. 8 on the facing upper side of the pendulum lifting plate 12. During a rotational movement of the drive hollow body 7 of the Abtastnocken 21 passes at the top of the pendulum lifting disc 12 in contact with various portions of the pendulum stroke cam 20, which is inclined in particular with respect to a plane orthogonal to the axis 6, so that an axial adjusting movement is transmitted to the pendulum lifting disc 12 , This axial adjusting movement is converted by the pendulum lifting disk 12 via the pendulum lever plunger 13 (FIG. 1) into a pivoting movement of the roller lever 14 and thus into a pendulum motion of the lifting rod and the saw blade. In Figs. 9 and 10, the pendulum lifting disc 12 is opposite the pivoting unit

1 1 in its top dead center (FIG. 9) or in its bottom dead center (FIG. 10). The top dead center represents the maximum upwardly deflected position of the pendulum lifting disk 12, the bottom dead center the maximum downwardly deflected position. These positions are in defined relative rotational positions between the drive hollow body 7 and the Pendelhubscheibe

12 reaches and depend on the current relative position between pendulum stroke control cam 20 and the Abtastnocken 21 on the upper side facing the pendulum lifting plate 12 from.

To limit the movement of Pendelhubscheibe 12 upwards the Pendelhubwahlschalter 22 can be actuated, which has a limiting cam 27, which depending on the current rotational position of the pivotally mounted Pendelhubwahlschalters 22 has a greater or lesser distance to the top of Pendelhubscheibe 12. In the illustrated embodiment, the Pendelhubwahlschalter 22 assumes a position in which the limiting cam 27, the lifting movement of the pendulum lifting plate 12 does not restrict upwards. However, by a rotation of the Pendelhubwahlschalters 22, the limiting cam 27 is compared to the pendulum lifting plate 12 in a relative position in which the axial stroke of the pendulum lifting plate 12 is limited. In this way, the pendulum stroke movement of the saw blade is limited.

Claims

claims

1 . Hand-held lifting saw machine, in particular jigsaw (1), with an oscillating lifting movement performing saw blade (2), which is driven by a motor-driven drive means (5), characterized in that the drive means (5) comprises a rotatable drive hollow body (7) is acted upon by the drive motor of the Hubsägemaschine and parallel to the saw blade lifting axis (6) is mounted, wherein the drive hollow body (7) a saw blade (2) holding, slidably mounted driver part (4) surrounds and the drive hollow body (7) and the driver part (4 ) cooperate via control means (17, 18, 19) in such a way that a rotational movement of the drive hollow body (7) in a stroke movement of the driver part (4) can be implemented.

2. Hubsägemaschine according to claim 1, characterized in that the drive hollow body (7) has an external toothing for driving via the drive motor.

3. Hubsägemaschine according to claim 1 or 2, characterized in that the control means comprise a control cam (17) and one with the control cam (17) cooperating drive cam (18, 19).

4. Hubsägemaschine according to claim 3, characterized in that the control cam (17) on the inner wall of the drive hollow body (7) is arranged.

5. Hubsägemaschine according to any one of claims 1 to 4, characterized in that the hollow drive body (7) surrounds a compensating mass portion (16), is displaceably mounted and a to the driver part (4) phase-displaced lifting movement, wherein a control means (17) on the drive hollow body ( 7) drives the compensating mass portion (16).

6. Hubsägemaschine according to claim 4 and 5, characterized in that the driver part (4) and the compensating mass portion (16) on opposite inner wall sides via a respective driver cam (18, 19) in the control cam (17) on the inner wall of the drive hollow body (7). intervention.

7. Hubsägemaschine according to one of claims 1 to 6, characterized in that on the driver part (4) a lifting rod (8) is pivotally mounted and the drive hollow body (7) via pendulum stroke control means (20, 21) with a pendulum lifting device for generating a the lifting movement superimposed pendulum movement about the pivot axis of the lifting rod (8) cooperates.

8. Hubsägemaschine according to claim 7, characterized in that the pendulum stroke control means comprise a pendulum stroke control cam (20) on the drive hollow body (7) and a Abtastnocken (21) on a Pendelhubscheibe (12) which acts on a pivoting unit (1 1), over which a transverse to the lifting movement directed pivoting movement on the saw blade (2) is transferable.

9. Hubsägemaschine according to claim 8, characterized in that the pendulum stroke control cam (20) on one end side of the drive hollow body (7) is arranged and the pendulum lifting disc (12) adjacent to the end face and coaxial with the drive hollow body (7) is arranged.

10. Hubsägemaschine according to claim 8 or 9, characterized in that the Pendelhubscheibe (12) relative to the pivoting unit (1 1) is mounted axially displaceable and a Pendelhubstößel (13) actuated, which is also mounted axially displaceable in the pivoting unit (1 1) ,

1 1. Hubsägemaschine according to one of claims 8 to 10, characterized in that the height of the pendulum stroke movement of the pendulum lifting disc (12) via a Pendelhubwahlschalter (22) is adjustable.

12. Hubsägemaschine according to one of claims 8 to 1 1, characterized in that the pivoting unit (1 1) is rotatably mounted about the saw blade lifting axis (6) or an axis parallel thereto.