EP2517835A2 - Power tool - Google Patents

Abstract

The tool has a tangential hammer mechanism (10) including an anvil (60) associated to an output shaft (30), and a hammer (70) associated to a drive shaft (50). The hammer is axially moved under force application of a spring (80) and a sliding block guide (90). The hammer is strikable against the anvil under rotation of the hammer around the drive shaft. The guide includes a thread-like control contour (91), which includes slopes in an anvil closer section (93) and anvil far section (94), respectively. The slopes are different from each other.

Description

Technical area

The invention relates to a hand tool. The hand tool can be realized for example in the form of a hammer drill or impact wrench. For example, the Tangentialschlagwerk produce a Schlagschraubbewegung the output shaft. In that case, the tool may be in the form of a screwdriver which can carry out a striking screw movement in the tool holder via the rotating and partially striking movement of the output shaft. The Tangentialschlagwerk is usually powered by a motor, possibly with the interposition of a transmission. The main components of a clutch-like tangential impactor are a hammer associated with a drive shaft of the clutch and an anvil associated with an output shaft of the clutch. The hammer can be axially against the force of a spring while twisting the same from the anvil and then again while twisting the same-accelerated by the force of the spring-striking against the anvil to be moved. The impact movement is practically tangential to the rotational movement. The rotational movement and axial reciprocating motion for the execution of a rotary impact are coupled by a slotted guide, so that the hammer ultimately positively moves under specification of the slotted guide. At a reversal point of the reciprocation, the hammer is triggered by the anvil. At another reversal point of the reciprocation, the hammer makes a pivotal strike against the anvil. In this way, the hammer can strike, for example, every half turn virtually tangential to the rotational movement of the anvil and transmit relatively high torque peaks during the rotary impact. Such high torque peaks would usually not be achievable by a continuous rotary drive of the output shaft. One The aforementioned Tangentialschlagwerk can be designed as a resonant spring-mass system for a comparatively narrowly defined torque range within which the actual operating point is determined by a drive speed of the drive for the drive shaft. The operating point is also characterized by a triggering moment, in which the hammer decouples from the anvil in the release position - ie the release torque when performing a separation of an engagement of the anvil and the hammer. In addition, the operating point is characterized by the torque transmittable at impact. Decisive for this are, inter alia, the moment of inertia of the hammer, the spring stiffness of the spring and the transfer function of the slotted guide, which is ultimately predetermined by a control contour of the slotted guide.

Within the scope of customary applications, a tangential striking device has a comparatively low release torque, which is achieved by means of a comparatively low spring rigidity. High torques requiring drilling of z. B. deep holes with large diameters is only partially possible using such a conventional Tangentialschlagwerks.

It would also be desirable to design a tangential impactor for applications with comparatively high torque requirements. A simple scaling up of the design parameters of a standard tangential impactor does not lead to the goal here, since this is regularly accompanied by an increase in the body masses of the tangential impactor. In a machine tool of the type mentioned, this would lead to a deterioration of the handling.

The task relating to the power tool is achieved by the invention with a hand tool of the type mentioned, is provided in accordance with the invention that the slide guide has a thread-like control contour having a first slope in a first section and a second slope in a second slope, wherein the first and second slopes are different.

Preferably, a first pitch angle α of the first pitch measured with respect to an axis of a cylindrical body for the link guide is greater than a second pitch angle β of the second pitch measured with respect to the axis. The slopes have in particular the same sign, ie the sections are part of a single thread-like course of the control contour. In a particularly preferred Further development may be provided that the first section forms an anvil-proximal section and the second section forms an anvil-distant section of the control contour and the first gradient is greater than the second gradient. In particular, the first and the second pitch may be only significantly different slopes of the control contour. That is, except for a continuous transition region as possible, there are practically only the first and second sections with significantly different gradients. Preferably, the first and second portions directly adjoin one another.

The invention is based on the consideration that a Tangentialschlagwerk for a user-friendly and comparatively low-weight hand tool machine should have a spring system with relatively low spring stiffness. On the basis of this, it has additionally been recognized that nevertheless a comparatively high release torque can be achieved if a slotted guide, in particular in an impact associated with, here e.g. first, section is preferably designed steeply. It has also been recognized that in order to transmit a comparatively high torque peak in a hammer to anvil stroke, a slotted guide, particularly in one of the hammer and anvil firing, here e.g. second, section preferably suitably flat. In principle, the invention has recognized that a first portion assigned to the impact and a second portion assigned to the triggering can be provided with a different first and second pitch of a thread-like control contour.

In contrast to a conventional control contour-for example, a uniform thread-like control contour with constant pitch over the entire course of the control contour, which is mounted on a spindle, the concept of the invention therefore provides a slotted guide with a thread-like control contour which has a slope that is varied in an adapted manner. This control contour adapted in the above-mentioned manner has a different pitch in a first section assigned to the torque transmission than in a second section assigned to triggering of the hammer and anvil. Preferably, the slide guide can also have a basically V-like - even double-threaded - executed control contour. However, this is in contrast to a previously known control contour with a single continuously rectified thread path in a V-leg provided, which also has a first pitch in a first portion of the V-leg and a second different pitch in a second different portion of the V-leg has the same sign.

With such a matched thread-like control contour of the guide slot, a relatively good impact as well as a relatively high release torque can be achieved; this is advantageous without the mass of Tangentialschlagwerks should be increased. In particular, a spring stiffness can nevertheless be kept relatively low.

Further advantageous developments of the invention can be found in the dependent claims and indicate in detail advantageous possibilities to realize the above-described concept within the scope of the task, as well as with regard to further advantages.

Bevozugt the anvil is integral with the output shaft and the spindle integrally connected to the drive shaft. Preferably, the slotted guide is on a cylindrical body, such as a shaft - e.g. Spindle or a hollow body formed; for example, on an outside or inside of the cylindrical body. These measures - individually or in combination - lead to a particularly compact and stable tangential impact mechanism.

Preferably, the slotted guide on a first control contour on a spindle between the drive shaft and output shaft. Alternatively, preferably in addition, the slotted guide has a second control contour on a shell inside of the hammer. In particular, by the interaction of the aforementioned first and second control contour in a preferred slotted guide can be an axial and rotary movement of hammer against anvil for performing a rotary-striking movement realize with advantage.

Under development, only the first control contour or only the second control contour of the slotted guide each having a first portion with the first slope and a second portion with the second different pitch. In a modification, it is also possible for the first control contour and the second control contour of the sliding guide each to have a first section with the first gradient and a second segment with the second differential gradient.

The first section preferably forms (in particular in each case) an anvil-proximal section and the second section forms an anvil-distant section of the control contour. The first slope is preferably greater than the second slope. In particular, a first pitch angle α of the first pitch measured with respect to an axis of a cylindrical body for the link guide is larger than a one measured with respect to the axle second pitch angle β of the second pitch. In a particularly advantageous manner, an increased release torque can be achieved with the tangential impactor, and the tangential impactor is nevertheless able to transmit a comparatively high torque peak, ie to execute a good impact. The control contour ensures a particularly safe and lossless power transmission in acting as a coupling Tangentialschlagwerk. The Tangentialschlagwerk is particularly suitable for carrying out high-torque-requiring work.

It has proved to be particularly advantageous that the first and second pitches are substantially single pitches of the control contour and the first and second portions are directly adjacent to each other. This leads to a comparatively simple design of the control contour. In principle, moreover, between the first and second section, a further section may be provided, which is provided as a transition section with a gradual slope adjustment or has a constant value lying between the first and second pitch.

In a particularly advantageous development, the control contour-preferably a first control contour-is formed by a closed link of the slotted guide. In a particularly preferred construction, a closed slot is formed in the form of a groove (eg, with a U-shaped cross-section), wherein a sliding block positively connected to the hammer can be moved in the slot.

In another particularly advantageous embodiment, the control contour is formed by an open link of the slide guide. Particularly preferably, the second control contour is formed by an open link of the slotted guide. In a particularly preferred construction, an open slide in the form of a running surface (with a flat cross-section) is formed, wherein on the running surface a forcibly guided connected to the hammer sliding block is movable.

In a particularly preferred training also explained with reference to an embodiment, the link guide is formed by an interaction of a closed gate on a spindle between the drive shaft and output shaft and an open gate on a shell inside of the hammer. It can alternatively also the slide guide by an interaction of a closed gate on a shell inside of the hammer and an open gate on a spindle between the drive shaft and Be formed output shaft. These types of slotted guide from a combination of a closed and an open backdrop have proven particularly useful.

In the context of an aforementioned particularly preferred development, the control contour is formed in the form of a groove of the tread, wherein a force-guided on the control contour sliding block is movable. In principle, the control contour can also be formed inversely thereto, for. B. with a web on or on which a sliding block is forced. In principle, a control contour of a slotted guide for realizing a suitable transfer function with two different gradients can be realized in a manner adapted to the design requirements.

The first section preferably forms an anvil-proximal section and the second section forms an anvil-distant section of the control contour, wherein the first gradient is preferably greater than the second gradient. In other words, the first pitch assigned to the transmission of the torque peak during impact is greater than the second pitch of the control contour assigned to the triggering of the hammer and anvil, in particular in the case of a first control contour located on the spindle.

In the context of such a development has been recognized that a torque peak with a relatively high amount is transferable when the largest possible part, in particular the entire rotational energy of the hammer in impact energy of the rotary shock (also called tangential impact) is transformed, d. H. is transformed into a torque. This can be supported by a comparatively flat design of the control contour measured against an axis. As part of a further development has been recognized that a release torque between the anvil and hammer is relatively high interpretability. This can be supported by a comparatively steep design of the control contour measured against an axis.

Preferably, the first slope increases in the first region near the anvil. The increase can be implemented gradually. The first section of greater pitch may also be in the form of a first anvil-proximal section of constant pitch greater than the second pitch in the second anvil-distal section. The second slope of the control contour is comparatively small. In this case, the pitch curve in the second section may gradually decrease. However, the second section can also be designed relatively simply as a section of constant second pitch, which is less than one first climb in the first section. In particular, a gradient curve in the transition from the first to the second section can be made gradual or graduated or as a simple step between the first and second gradient.

In particular, it is provided that in the engaged position of the anvil and the hammer for the execution of a Tangentialschlag a positively forcibly connected to the hammer sliding block in the first section of the control contour is arranged. This advantageously prevents a transfer of a torque peak being limited by a resistance-causing force absorption in the second section with a lesser second gradient. Rather, it is ensured that the sliding block in the range of comparatively larger first slope allows the transmission of virtually the full rotational energy of the hammer as torque to the anvil and does not counteract.

To perform a Tangentialschlags the anvil and the hammer is preferably in fully engaged position. In a rotational turning point of the reciprocating motion of the hammer, the anvil and the hammer have an engaging portion which may be predetermined by the length of stopper means, for example. Advantageously, it is provided that the first section, in particular of a larger pitch, has an axial extent which makes up at least 20% of the axial extent of the engagement area. This ensures that at least on the remaining 20% of the axial extent of the engagement region an advantageously larger first slope is present, which allows a transmission of particularly high torque peaks. The result tends to be improved in the impact, the greater the axial extent of the first section. Advantageously, the axial extension of the section makes up at least 20% of the axial extent of the engagement region or approximately corresponds to the extent of the engagement region without, however, exceeding it.

Also, it has proven to be advantageous that at least in the release position of the anvil and the hammer to perform a separation of an engagement of the same a forcibly connected to the hammer sliding block in the second section of the control contour is arranged. In this way it is ensured that the sliding block allows only a high release torque in view of the lower second slope of the slotted guide.

A stop means is formed in the anvil and / or hammer, preferably in the form of at least one cam. Particularly advantageous two cams have proven. The cams are advantageous on a ring circumference of the anvil or the Hammer formed. The ring circumference can be arranged on the head side or laterally of the anvil and / or hammer. The development with two cams allows with appropriate adaptation of the control contour a triggering or tangential striking of the hammer and anvil at every half turn. With further suitable adaptation of the slotted guide more than two cams may be provided, for example in the form of a ring gear. In particular, this may limit a rotational movement to a fraction of a full revolution of the hammer.

Within the scope of a particularly preferred use of the tangential impact tool, a hand tool machine in the form of a rotary hammer can be formed. Preferably, the Tangentialschlagwerk is designed to perform the function of a slip clutch. In this use, the tangential impactor may also preferably be operated out of resonance of the corresponding spring-mass system. The second slope in the second anvil distant portion of the control contour is preferably designed such that the tangential impactor has a particularly high release torque to allow the normal drilling operation of the hammer drill, d. H. in normal drilling operation just do not trigger.

In a modified development of a use, it has proved to be advantageous to form the power tool in the form of a striking screwdriver. In this development, the Tangentialschlagwerk is designed to perform the function of a Schlagschraubbewegung. Here, it has proven to be particularly advantageous to interpret the Tangentialschlagwerk for a resonant operation of the associated spring-mass system. This can be done for a defined comparatively limited torque range. In particular, the first slope in the first anvil-proximal portion is designed with a comparatively high value in order to achieve a particularly high torque peak transfer during the rotary impact between the hammer and the anvil.

An adaptation of the control contour according to the concept of the invention is especially advantageous for the two aforementioned cases of use. In addition, the aforementioned cases of use can also be combined with one another by an optimized adaptation of both the first section with a comparatively larger pitch and the second section with a comparatively smaller pitch. Overall, the execution of a demand-matched Tangentialschlagwerks possible, the transfer of high torque peaks in the rotary impact on the one hand and the operation at high torque requirements below a tripping torque of the tangential impact allowed. In particular, a triggering moment of the tangential impactor can be made comparatively high by increasing the first pitch in the first region near the anvil so that the tangential impactor behaves virtually like a friction clutch. Nevertheless, a comparatively good torque transmission in the anvil distant section is ensured.

embodiments

Embodiments of the invention will now be described below with reference to the drawings. These are not intended to scale the embodiments nofiniendlichlich, but the drawings, where appropriate for explanation, executed in a schematized and / or slightly distorted form. With regard to additions to the teachings directly recognizable from the drawing reference is made to the relevant prior art. It should be noted that various modifications and changes may be made in the form and detail of an embodiment without departing from the general idea of the invention. The disclosed in the description, in the drawing and in the claims features of the invention may be essential both individually and in any combination for the development of the invention. In addition, all combinations of at least two of the features disclosed in the description, the drawings and / or the claims fall within the scope of the invention. The general idea of the invention is not limited to the exact form or detail of the preferred embodiments shown and described below or limited to an article which would be limited in comparison with the subject matter claimed in the claims. For the given design ranges, values within the stated limits should also be disclosed as limit values and be arbitrarily usable and claimable.

• Fig. 1 eine schematische Darstellung einer Handwerkzeugmaschine -vorliegend als ein Bohrhammer oder ein Schlagschrauber- mit einem Tangentialschlagwerk;
• Fig. 2 eine schematische Darstellung des Tangentialschlagwerks der Handwerkzeugmaschine der Fig. 1, wobei der Hammer und der Amboss des Tangentialschlagwerks in der Art eine Explosionsdarstellung vergleichsweise weit auseinander gezogen sind, um den Verlauf der gewindeartigen Steuerkontur der Kulissenführung darzustellen - zur Erläuterung des Konzepts der Erfindung ist eine Kulissenführung mit einer einfachen Kulisse einer gewindeartigen Steuerkontur mit einer ersten und zweiten Steigung gezeigt, die gleiches Vorzeichen haben und vom Betrag unterschiedlich sind;
• Fig. 3A eine detaillierte Darstellung einer bevorzugten konstruktiven Realisierung eines Tangentialschlagwerks für eine besonders bevorzugte Ausführungsform einer Handwerkzeugmaschine in einer Seitenansicht (C) sowie in zwei Schnittansichten (B) und (A) dazu;
• Fig. 3B eine Stirnansicht auf die Seitenansicht der Fig. 3A (C);
• Fig.4 in Ansicht (A) eine perspektivische Ansicht auf den Hammer für die konstruktive Realisierung des Tangentialschlagwerks der Fig. 3A, Fig. 3B und in Ansicht (B) eine Schnittansicht des Hammers der Ansicht (A).

Further advantages, features and details of the invention will become apparent from the following description of the preferred embodiments and from the drawing; In detail, the drawings show in:

• Fig. 1 a schematic representation of a hand tool - present as a hammer drill or impact wrench - with a Tangentialschlagwerk;
• Fig. 2 a schematic representation of the tangential impact of the power tool of the Fig. 1 , with the hammer and the anvil of the Tangential impact in the manner of an exploded view are drawn comparatively far apart to illustrate the course of the thread-like control contour of the slotted guide - to illustrate the concept of the invention, a slotted guide is shown with a simple backdrop of a thread-like control contour with a first and second pitch, have the same sign and are different from the amount;
• Fig. 3A a detailed representation of a preferred structural realization of a Tangentialschlagwerks for a particularly preferred embodiment of a hand tool in a side view (C) and in two sectional views (B) and (A) thereto;
• Fig. 3B an end view on the side view of Fig. 3A (C) ;
• Figure 4 in view (A) is a perspective view of the hammer for the constructive realization of the tangential impact of Fig. 3A, Fig. 3B and in view (B) is a sectional view of the hammer of the view (A).

Fig. 1 shows a hand tool 100, which can be kept - for example in the form of an impact wrench - on a handle 102 formed by the housing 101 and the drive 104 can be activated here via a trigger 103 in the form of a lever or push button. The drive 104 is formed here with a motor 105 in the form of an electric motor having an in Fig. 2 indicated rotational movement 1 via a gear 106 and a drive shaft 50 transmits to a spindle 20. The spindle 20 is disposed between the drive shaft 50 and an output shaft 30 and in this case integrally connected to the drive shaft 50. The rotational movement 1 of the spindle 20 is about the in Fig. 2 Tangential Schlagwerk 10 shown in more detail -dh reacted under Drehschlagendem interaction of the hammer 70 and anvil 60- in a rotating and partially tangential striking motion of the drive shaft 30; this rotating and partially -in the tangential direction of the rotary movement-striking movement of the drive shaft 30 is transmitted to a tool not shown in detail in a tool holder 40 of the power tool 100.

The on the same axis 2 as the spindle 20 and the output shaft 30 mounted in the tool holder 40 tool - for example, a screwdriver or the like- is capable of higher torques than with the continuous torque output of the motor 105 achievable, for example, a screw to transfer. The tangential impactor 10 can be modeled as part of a spring-mass system. It is operated in the present case in the resonant range, which optimizes the torque peak transfer to the tool and the screw. A preferred application of an impact wrench shown is z. As the screwing of screws, setting anchors in concrete or the like hard ground.

Referring to Fig. 2 The tangential impact mechanism 10 has an anvil 60 assigned to the output shaft 30 and a hammer 70 assigned to the drive shaft 50. Under the action of force of a spring 80 and a slotted guide 90, the hammer 70 can here be moved axially while twisting the same-practically tangentially to the direction of rotation-striking the anvil 60. The axial movement 4 is presently indicated by an arrow as a reciprocating motion and the rotational movement 3 is indicated by a further arrow. A forward turning point of the axial movement 4 follows the abutment of the hammer 70 on the anvil 60 by a rotary stroke (also called a tangential stroke) in which the torque peak is transmitted between the hammer 70 and the anvil 60. A rear reversal point of the axial movement 4 is beyond a triggering location of hammer 70 and anvil 60. The trip location is approximately in the region of the transition between the first and second sections 93, 94 of the control contour 91 explained below; ie approximately in the region of the kinking of the control contour 91. In Fig. 2 For example, the hammer 70 is shown far beyond the trip location to more clearly show the course of the slotted guide 90. In the present case, the anvil 60 has stop means in the form of two anvil cams 64 - of which only an anvil cam 64 lying on one side of the anvil is shown.

In the Fig. 2 The bottom surface of the anvil cam 64 shown serves as the anvil striking surface 62. A corresponding impulse mediated by abutment of the hammer 70 is imparted to the anvil striking surface 62 so that a torque peak is transmitted from the hammer 70 to the anvil 60. Accordingly, the hammer 70 has two hammer cam 74, wherein the in Fig. 2 recognizable front of the lower hammer cam 74 serves as a hammered surface 72. This provided with abutment against the anvil striking surface 62 for transmission of said pulse. In the present case, a torque peak is transmitted to the anvil 60 during each half revolution of the spindle 20. The two anvil cams 64 and two hammer cams 74 are designed accordingly and placed in coordination with the slotted guide 90.

The slide guide 90 here has a closed slot in the form of a groove 96 which is formed in the spindle 20 and the single continuous course of a thread-like control contour 91 follows. In the groove 96 is a here executed as a ball sliding block 92, via which the hammer 70 with a degree of freedom movable-forcibly guided by the slide guide 90 sits on the spindle 20 and is connected to this form-fitting manner; namely movable under execution of the reciprocating movement in the axial direction 4 and the rotational movement in the tangential direction 3. The anvil abutment surfaces 62 and hammer abutment surfaces 72 are aligned perpendicular to the circumferential direction of the anvil 70 and hammer 60 here. A perpendicular to the anvil striking surface 62 or hammer striking surface 72 thus points in a tangent direction to the annular circumference of the anvil 60 that surrounds the anvil cam 64 and the annular circumference of the hammer 70 that surrounds the hammer cam 74.

In the present case, the slotted guide 90 has a first anvil-proximal portion 93 and a second anvil-distal portion 94, the first portion having a smaller axial extent than the second portion 94. The second portion 94 directly adjoins the first portion 93. In the first section 93, the control contour 91 has a single thread-like course with a first, comparatively steep slope. In the second section 94, the control contour 90 has a single thread-like progression which continues in the same direction in the same direction in the first section 93 and has a second, flatter slope. The second, a smaller pitch angle β against the axis 2 having slope is thus less than the first slope with a larger pitch angle α. In addition, the first portion 93 has an axial extent that is slightly smaller than the axial extent of an engagement portion 95 of anvil 60 and hammer 70. In the present case, the engagement region 95 is determined by the axial extent of the stop means-namely here the anvil cam 64 and the hammer cam 74-.

By these proportions of the axial extent of the first portion 93 and the engagement portion 95 is firstly ensured that in engagement position of the anvil 60 and the hammer 70 -dh to perform a tangential impact on the anvil striking surface 62 and the hammered surface 72- one with the hammer 70 forcibly connected sliding block 92 in the first section 93 of the control contour 90 is located. In addition, the comparatively steep gradient of the control contour 91 in the first section 93 ensures a secure engagement of the hammer 70 and the anvil 60. Due to the sufficiently graduated transition of the second pitch -with a smaller pitch angle β-to In the dynamic operation of the tangential impactor 10, it is also ensured that a rotational movement of the hammer 70 shortly before the tangential impact between the hammer 70 and the anvil 60 approaches the first, steeper slope of the first portion 93 in the tangential direction to the first slope is sufficiently accelerated and on the other hand, the rotational energy can be transmitted as a torque peak.

In contrast, in the acceleration phase, the force potential of the spring 80 largely discharges in the region of the second portion 94 of the control contour 91 and the hammer 70 is forcibly pushed forwards over the slotted guide 90 and against a mass inertia of the hammer 70. In this way, a particularly high amount of torque peak between anvil 60 and hammer 70 is achieved in the second section 94 of the control contour 91. This is also transmitted to the tool in an improved manner in the first portion 93 of the control contour 91 and, moreover, the holding torque is increased due to the larger pitch angle α in the control contour 91. For example, a screw can be more effectively screwed into a solid surface.

Thus, after a rotational shock and further executed rotary movement 1 of the spindle 20, first a torque-holding coupling between the drive 104 and tool on the tangential impactor 10 is made, since now anvil 60 and hammer 70 are located on the anvil cam 64 and hammer cam 74 in engagement. The engagement state is maintained as a result of the first portion 93 of the control contour 93 with a larger pitch angle α in an improved manner.

With increasing resistance of the tool against the rotational movement 1 of the hammer 70 is pulled out of the engaged state in the engagement portion 95 against the spring force of the spring 80, i. the spindle 20 is positively driven by the hammer 70 via the slide guide 90- through. In doing so, the hammer 70 remains in engagement with the anvil 60 via the hammer cam 74 and the anvil cam 64 until the head sides 63, 73 of the anvil cam 64 or hammer cam 74 can rotate past one another. This is done practically as soon as the anvil 60 and hammer 70 have moved farther apart than the axial extent of the engagement region 95.

The firing moment of hammer 70 and anvil 60 is determined by the first slope of the control contour 91 according to the first pitch angle α. In other words is in the release position of the anvil 60 and the hammer 70 to perform the separation of the engagement of the same with the hammer 70 forcibly connected sliding block 92 in the second section 94 of the control contour 90 and passes into this. Due to the comparatively large selected pitch angle α of the first pitch compared to the pitch angle of the second pitch β, the release torque is much greater than would be the case with a smaller pitch angle. A thus relatively large designed release torque is present, although the spring stiffness of the spring 80 in the present case is kept relatively low. The comparatively high release torque is also achieved without having to increase the total mass of the tangential impactor 10. The tangential impactor 10 thus allows the operation of the hand tool 100 in the form of a impact wrench in applications with comparatively large torques in an improved manner. Also, this allows the use of the tangential impactor 10 in a hammer drill under stress with comparatively large torques occurring, for example, when drilling deep holes and / or large diameter. In particular, the presently designated Tangentialschlagwerk 10 is also suitable as a slip clutch for example, a hammer drill or impact wrench. In this case, the first slope with pitch angle α is chosen so large that a separation of an engagement between the hammer 70 and anvil 60 at normal torque load of the output shaft 30 practically does not occur.

After the hammer 70 and anvil 60 have been triggered, a sufficient rotational acceleration of the hammer 70 takes place in the second section 94, so that a torque peak transfer is likewise optimized.

In Fig. 3A as a side view and in Fig. 3B as an end view of another Tangentialschlagwerk 11 is shown, which for a particularly preferred embodiment of a schematically in Fig. 1 Hand tool 100 shown is suitable. Fig. 3A and Fig. 3B show to a drive shaft 51 which is connected in a manner not shown, for example via a gear 106 with a motor 105 of a power tool 100 rotationally driven. On an output shaft 31, a tool holder 40 or the like for receiving a tool, not shown, of the power tool 100 can be mounted in a manner not shown. Recognizable off Fig. 3A and 3B is the output shaft 31 by means of the drive shaft 51 and a Tangentialschlagwerk 11 in a rotating and partially beating movement displaceable - this basically analogous to the above with reference to Fig. 2 explained principle. For this purpose, the tangential impact mechanism 11 has an output shaft 31 associated anvil 61 and a the drive shaft 51 associated hammer 71. The hammer 71 and the anvil 61 act in principle in the already principle with reference to Fig. 2 explained way together.

Also at the in Fig. 3A and Fig. 3B shown constructive realization of the hammer 71 under the action of a spring 81 and one of the views (A) and (B) of Fig. 3A as well as the Fig. 4 apparent slide guide 190 axially movable and twisting of the hammer 71 this is against the anvil 61 beatable. In the present case, the anvil 61 is integrally connected to the output shaft 31. A spindle 21 is presently integrally connected to the drive shaft 51. The spring 81 is concentric with the spindle 21. Overall, the drive shaft 51, the spindle 21, the anvil 61 and the output shaft 31 are each arranged concentrically to the axis 2 to form the tangential impact mechanism 11. The spring 81 and the hammer 71 sit to move also concentric to the axis 2 on the spindle 21. The spring 81 is supported on the side of the drive shaft 31 from an annular stop 22, which sits at a shoulder between the spindle 21 and drive shaft 51. On the side of the output shaft 31, the spring 81 is supported on an end face 75 of the hammer 71 and biases it, or is able to move it in the direction of the axis 2 under positive guidance of the guide link 190. Both the end face 75 and the annular stop 22 for the spring 80 are shown schematically in FIG Fig. 2 shown.

The slotted guide 190 for the preferred constructive realization of the tangential impactor 11 is further referred to the views (A) and (B) to illustrate the sections A - A and B - B of the Fig. 3A and referring to the Fig. 4 described. In the present case, the slotted guide 190 has a first control contour 91.1 and a second control contour 91.2. In the present case, the first control contour 91.1 indicates the course of a closed slide in the form of a groove 180 in the spindle 21. The groove 180 is threadedly introduced into the spindle 21 and has a basically V-shaped course, the -wie in view (B) of Fig. 3A evident- in plan symmetrical to the axis 2 extends. A first branch 181 of the V-shaped groove 180 and a second branch 182 of the V-shaped groove 180 are so far mirror-symmetrical and formed in principle gleichverlaufend. Each of the branches 181, 182 of the V-shaped groove 180 has a first portion 193 with a first pitch and a second portion 194 with a second pitch. In the present case is analogous to in Fig. 2 illustrated principle of a control contour 91 also in the slotted guide 190 in the first section 193, a first slope of a control contour 91.1 greater than a second slope of a control contour 91.1 in the second section 194th Specifically, for the slotted guide 190 in each of the branches 181, 182, a first pitch angle α of the first pitch measured with respect to the axis 2 of the spindle 21 for the slotted guide 190 is greater than a second pitch angle β of the second measured relative to the axis 2 Gradient in the second section 194.

The first thread-like control contour 91.1 is assigned to the outer shell surface of the spindle 21 in the tangential impact mechanism 11, a second in Fig. 4 apparent control contour 91.2, which is introduced in a shell inside of the hammer 71. The second control contour 91.2 specifies the course of an open backdrop in the form of a tread. The second control contour 91.2 also has a first section 193 and a second section 194 provided with the same reference numerals for the sake of simplicity. Again, in the first section 193, a slope of the second control contour 91.2 measured with respect to the axis 2 is greater than a slope of the control contour 91.2 in the second section 194. In particular, from view (B) of FIG Fig. 3A and view (A) of Fig. 4 recognizable that a first slope of the control contours 91.1, 91.2 is so large that approach the control contours 91.1, 91.2 in the course of a virtually paraxial course to the axis 2. The largest first pitch angle α in the first section 193 thus results at the top of the overall V-shaped course of the control contour 190 where the first branch 181 and the second branch 182 in collision at the height of the axis 2-- collide. In the direction of the smaller second gradient in the section 194, the first slope of the control contour 91.1, 91.2 of the first section 193 asymptotically merges into the second slope of the second section 194. Regardless, the first and second pitches - as exemplified by the pitch angles α, β - are the substantially unique different pitches of the control contour 190.

The interaction of the first control contour 91.1 and the second control contour 91.2 is best obtained from view (A) of Fig. 3A. In the sectional view (A), it can be seen that a sliding block 192 resting in the groove 180 of the spindle 21 as well as on the running surface 170 of the hammer 71 is forcibly guided. In this way, the movement of the hammer 71 on the one hand and the spindle 21 on the other hand relative to each other by the course of the first and second control contour 91.1, 91.2 set. Similar to the already with reference to Fig. 2 explained principle is the hammer 71 while rotating the same axially along the axis 2 of the spindle 21 according to the specification of the slotted guide 190 movable. The bias of the spring 81 is thereby converted into kinetic energy of the hammer 71, which emits this as a torque peak when striking against the anvil 61. Beat it Hammer cam 74 and anvil cam 64 in the view (B) of Fig. 3A and Fig. 3B shown manner to each other.

In the engaged position of the anvil 61 and the hammer 71 for the execution of the rotary blow is positively connected to the hammer 71 associated sliding block 192 in the steep slope of the control contour 91.1 in the first section 193 and then goes into the other first section 193 of the second control contour 91.2 Traversing the top of the V-shaped control contour 190 via. As the torque on the spindle 21 is further increased by the drive 104 and the drive shaft 51, the anvil 61 and hammer 71 eventually disengage by disengaging the anvil cam 64 and hammer cam 74. Approximately in the release position reached in this way, the positively driven sliding block 192 merges into the second section 194 of the slotted guide 190, ie into the region of the shallower second gradient with a gradient angle β. Finally, the sliding block 192 further passes through the groove 180 of the slotted guide 190 circumferentially of the spindle 21 and thus passes into the first portion 194 of the first branch 181 of the groove 180. The movement of the sliding block 192 then continues on the other side of the spindle 21 in basically the same way. In total, one stroke of the hammer 61 and the anvil 71 is thus carried out per half revolution of the spindle 21.

In the present case, this results in a particularly preferred acceleration of the hammer 71-due to the shallower pitch with second pitch angle β in the second section 194 of the slotted guide 190-- and-due to the steeper pitch with first pitch angle α in the first section 193 of the slotted guide 190. a timely and compact stroke with a comparatively high torque peak transfer between hammer 71 and anvil 61. In addition, a relatively high release torque of the hammer 71 against the anvil 61 is achieved by the steeper slope with first pitch angle α in the first section 193 of the slide guide 190. Again, this comparatively high release torque can be achieved with comparatively low spring stiffness of the spring 81 and at comparatively low mass of the tangential impact device 11.

Expressed in simple terms, the first section 193 of the slotted guide 190 primarily supports the formation of a comparatively high triggering torque. The second portion of the slotted guide 190 is primarily designed to build and transmit a comparatively high torque peak between the hammer 71 and the anvil 61.

In order to enable a comparatively good impact between the hammer 71 and the anvil 61, the transition between the second section 194 is comparatively narrow. In other words, an extension of the transitional area between the first pitch angle α and the second pitch angle β is held comparatively small against the extension of the sections 194, 193. This turns out - from views (B) of Fig. 3A and Fig. 4 apparent - in an approximately kink-like transition between the first portion 193 and the second portion 194 of the control contour 91.1 and the second control contour 91.2. At the transition of the hammer 71 is due to the shallower pitch of the control contour 91.1, 91.2 comparatively high speeds.

In the concrete from view (B) of Fig. 3A apparent case of pitch angles α, β, these are selected as follows. A measured against the axis 2 and counterclockwise first pitch angle α is present rather above 135 °, ie between 135 ° and 180 ° in the course of the first portion 193 of the control contour 91.1, 91.2. A measured against the axis 2 and counterclockwise second pitch angle β of the second portion 194 is rather below 135 °, ie concretely approximately between an angle of 90 ° to 135 ° in the region of the second portion 194 of the control contour 91.1, 91.2. It is also to be understood that the first pitch angle α asymptotically approaches the angle 180 ° with the course of the control contour 91.1, 91.2 to the axis 2. With transition from the first section 193 to the section 194, the control contour 91.1, 91.2 changes from the first pitch angle α into the second pitch angle β.

On the flat part of the slotted guide 190 in the transition between the first branch 181 and the second branch 182, the second pitch angle β approaches the angle 90 ° asymptotically. A comparatively smooth transition of the sliding block 192 between the branches 181, 182 -jeweils on the front and back of the spindle 21 and respectively at the tips of the V-shaped course of a control contour 91.1, 91.2 - is thus possible.

Claims (11)

Hand tool (100), in particular in the form of a hammer drill or impact wrench, with - One on an output shaft (30, 31) mounted tool holder (40) for receiving a tool, wherein - The output shaft (30, 31) by means of a drive shaft (50, 51) and a Tangentialschlagwerk (10, 11) is displaceable in a rotating and partially striking movement, and wherein - The Tangentialschlagwerk (10, 11) one of the output shaft (30, 31) associated anvil (60, 61) and one of the drive shaft (50, 51) associated hammer (70, 71), wherein the hammer (70, 71) below Force action of a spring (80, 81) and a sliding guide (90, 190) is axially movable and can be beat against the anvil (60, 61) while rotating the hammer (70, 71) about the drive shaft (50, 51), characterized in that
the slide guide (90, 190) has a thread-like control contour (91, 91.1, 91.2) which has a first pitch in a first portion (93, 193) and a second pitch in a second portion (94, 194) and second slope are different. Hand tool (100) according to claim 1, characterized in that the slotted guide (90, 190) has a first control contour (91.1) on the drive shaft (20, 21, 50, 51) and / or a second control contour (91.2) on a shell inside of the hammer (70, 71). Hand tool (100) according to one of claims 1 to 2, characterized in that
the first control contour (91.1) and / or the second control contour (91.2) of the slide guide (90, 190) each have a first portion (93, 193) with the first pitch and a second portion (94, 194) with the second differential pitch , Hand tool (100) according to one of claims 1 to 3, characterized in that
the first section (93, 193) forms an anvil-proximal section and the second section (94, 194) forms an anvil-distant section of the control contour (91, 91.1, 91.2) and the first gradient is greater than the second gradient. Hand tool (100) according to one of claims 1 to 4, characterized in that
a first helix angle (α) of the first pitch measured with respect to an axis (2) of a cylindrical body for the slotted guide (90, 190) is greater than a second helix angle (β) of the second pitch measured relative to the axis (2) , Hand tool (100) according to one of claims 1 to 5, characterized in that
a closed backdrop of the slotted guide (90, 190) in the form of a groove (96) is formed, wherein in the groove (96) with the hammer (70) forcibly connected sliding block (92) is movable and / or
an open backdrop of the slotted guide (90, 190) is formed in the form of a running surface, wherein on the running surface with the hammer (70) positively guided associated sliding block (92) is movable. Hand tool (100) according to one of claims 1 to 6, characterized in that the first and second pitch are only substantially different slopes of the control contour (91, 91.1, 91.2) and the first section (93, 193) and the second section (94, 194) directly adjoin one another. Hand tool (100) according to one of claims 1 to 7, characterized in that
in the engaged position of the anvil (60, 61) and the hammer (70, 71) for performing a rotary impact with the hammer (70, 71) forcibly connected sliding block (92, 192) in the first portion (93, 193) of the control contour (91 , 91.1, 91.2) is arranged. Hand tool (100) according to one of claims 1 to 8, characterized in that in the release position of the anvil (60, 61) and the hammer (70, 71) to perform a separation of an engagement with a hammer (70, 71) forcibly guided connected sliding block (92, 192) in the second portion (94, 194) of the control contour (91, 91.1, 91.2) is arranged. Hand tool (100) according to one of claims 1 to 9, characterized in that the anvil (60, 61) and the hammer (70, 71) each have a mutually facing engagement portion (95) with stop means for performing a rotary impact and a stop means in shape of at least one, preferably two, cams (64, 74) is formed on a ring circumference of the anvil (60, 61) and / or hammer (70, 71) having a transversely to the circumferential direction impact surface (62, 72). Hand tool (100) according to one of claims 1 to 10, characterized in that
the first portion (93) has an axial extent which is in a range between 0.1 times and 1.0 times, in particular greater than 0.2 times, the axial extent of the engagement region (95).

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