Mechanical percussion mechanism

Abstract

The invention relates to a mechanical impact mechanism (100) for an impact drive of an insert tool (201) of a hand-held power tool (200), comprising a rotatably mounted intermediate shaft (101), an impact body (103) and a rotatably mounted output shaft (105), wherein the intermediate shaft (101) and the impact body (103) each comprise at least one guide groove (111, 113) for guiding at least one guide body (115), and wherein a guide surface (117) of the guide groove (111) of the intermediate shaft (101) and / or a guide surface (119) of the guide groove (113) of the impact body (103) is designed as a kink-free and / or edge-free surface.

Description

[0001] The present invention relates to a mechanical impact mechanism for a hand-held power tool, in particular a rotary impact wrench. State of the art

[0002] Mechanical impact mechanisms for rotary impact wrenches are known from the prior art. However, a known problem with these impact mechanisms is the high mechanical stress on the components of the impact mechanism.

[0003] The task is to provide an improved mechanical impact mechanism for a hand-held power tool.

[0004] The task is solved by the percussion mechanism of the independent claim. Advantageous embodiments are the subject of the dependent claims.

[0005] According to one aspect, a mechanical impact mechanism is provided for an impact drive of an insert tool of a hand-held power tool, comprising a rotatably mounted intermediate shaft, an impact body and a rotatably mounted output shaft, wherein the intermediate shaft and the impact body each comprise at least one guide groove for guiding at least one guide body, and wherein a guide surface of the guide groove of the intermediate shaft and / or a guide surface of the guide groove of the impact body is designed as a kink-free and / or edge-free surface.

[0006] This allows for the technical advantage of an improved impact mechanism. The kink-free and / or edge-free guide surfaces of the guide grooves enable the guide elements to move within the grooves with reduced energy loss. Furthermore, wear on the guide grooves and guide elements can be reduced.

[0007] Guide grooves, as defined in the application, are the segments of the grooves which, in the working area, define the coupling of the axial displacement with the relative rotation between the impact body and the intermediate shaft.

[0008] For the purposes of the application, a guide surface of a guide groove is an inner surface of the respective guide groove. When the guide body is guided in the guide groove, the guide body is positioned within the guide groove and rests on the guide surface of the guide groove. The guide surface is formed by the recess of the guide groove and describes the portion of the recess on which the guide body rests.

[0009] "Kink-free" or "edge-free" in the context of the application means that no kinks or edges are formed within the guide surfaces. In particular, no edges or kinks are formed in the guide surfaces that intersect the guide paths of the guide bodies when guided in the guide grooves.

[0010] In the prior art, the striking element is also called a hammer or rotary hammer.

[0011] According to one embodiment, the guide groove of the intermediate shaft and / or the impact body has a substantially parabolic shape.

[0012] This allows for the technical advantage that the parabolic shape of the guide grooves enables the most energy-optimized guidance of the guide bodies.

[0013] The guide groove's path refers to its longitudinal direction. It defines the path followed by the guide body as it moves through the groove. The path is essentially parabolic, meaning that deviations from a perfect parabolic shape are possible.

[0014] According to one embodiment, a circumferential line of the guide groove of the intermediate shaft and / or the impact body is designed as a kink-free circumferential line.

[0015] This allows the technical advantage to be achieved that the guide surfaces are designed as smooth and kink-free or edge-free guide surfaces.

[0016] The circumferential line of the guide groove describes an outer edge of the recess by which the guide groove is defined.

[0017] According to one embodiment, the circumferential line and / or the guide surface of the guide groove of the intermediate shaft and / or the impact body can be represented by a continuously differentiable function.

[0018] This allows for the technical advantage of generating optimally kink-free and edge-free guide surfaces for the guide grooves.

[0019] A continuously differentiable function is a mathematical function that is differentiable in a predetermined range and whose derivative is a continuous function in that predefined range.

[0020] According to one embodiment, the function is at least twice continuously differentiable.

[0021] This allows for the technical advantage of generating optimally kink-free and edge-free guide surfaces for the guide grooves.

[0022] According to one embodiment, the curvature of the guide groove is smaller than the curvature of the guide body.

[0023] This allows the technical advantage to be achieved that the guide bodies can be guided in the guide grooves with minimal friction.

[0024] The curvature of the guide groove is a curvature of the recess of the guide groove perpendicular to the course of the guide groove.

[0025] In one embodiment, the guide body is designed as a ball.

[0026] This allows the technical advantage to be achieved that the guide bodies can be guided in the guide grooves with minimal friction.

[0027] According to one embodiment, the axial movement of the striking body along the course of the guide groove is continuous and non-linear with respect to a relative angle between the striking body and the intermediate shaft.

[0028] This allows for the technical advantage of achieving the most energy-efficient guidance of the guide bodies in the guide grooves, minimizing energy losses in guiding the guide bodies within the guide grooves.

[0029] The terms continuous and nonlinear are to be understood mathematically. The shape of the guide groove is therefore a mathematical continuous and nonlinear function.

[0030] The relative angle describes an angle of relative rotation between the intermediate shaft and the impactor.

[0031] The striking element does not perform a purely axial movement, but always also exhibits a rotational movement. This refers to the axial component of the screw motion performed by the striking element.

[0032] According to one embodiment, the course of the guide groove of the intermediate shaft and / or the impact body is mirrored at a reversal point.

[0033] This achieves the technical advantage that the symmetrical shape of the guide grooves ensures symmetrical guidance of the guide elements within the grooves. This symmetrical guidance, in turn, is energy-efficient with minimal energy losses.

[0034] The turning point is formed by a vertex of the essentially parabolic curve.

[0035] According to one embodiment, the lengths of the guide grooves of the intermediate shaft and the impact body are identical or different.

[0036] This allows for the technical advantage that the guide grooves can be adapted to specific requirements. Their lengths can be adjusted to the radii of the intermediate shaft and the impact element, ensuring the most uniform guidance of the guide elements within the guide grooves.

[0037] The length of a guide groove runs between the endpoints of the guide groove. The length follows the path of the guide groove. The endpoints are defined by the circumference of the guide groove.

[0038] According to one embodiment, the slopes of the guide grooves of the intermediate shaft and the impact body are identical or different from each other.

[0039] This allows the technical advantage to be achieved that the profiles of the guide grooves can be adapted to the designs of the intermediate shaft and the impact body, for example to the radii of the intermediate shaft and the impact body, in order to achieve the most energy-efficient guidance of the guide bodies in the guide grooves.

[0040] For the purposes of this application, a slope is a mathematical slope of a mathematical function.

[0041] According to one embodiment, the slopes of the guide grooves of the intermediate shaft and the impact body are either constant or variable.

[0042] This allows the technical advantage to be achieved that the profiles of the guide grooves can be adapted to the designs of the intermediate shaft and the impact body, for example to the radii of the intermediate shaft and the impact body, in order to achieve the most energy-efficient guidance of the guide bodies in the guide grooves.

[0043] A constant slope is the slope of a linear mathematical function. A variable slope is a non-constant slope of a non-linear function.

[0044] In one embodiment, the striking mechanism is designed as a rotary striking mechanism.

[0045] This allows for the technical advantage of providing an improved rotary impact mechanism.

[0046] According to one aspect, a hand-held power tool with a mechanical impact mechanism is provided according to one of the preceding embodiments.

[0047] This allows for the technical advantage of providing an improved hand-held power tool with an improved impact mechanism offering the technical advantages described above.

[0048] According to one embodiment, the hand-held power tool is designed as a rotary impact wrench.

[0049] This allows for the technical advantage of providing an improved impact wrench.

[0050] Embodiments of the invention are described with reference to the following figures. The figures show: Fig. 1 a schematic representation of a hand-held power tool with a mechanical impact mechanism according to one embodiment; Fig. 2 a schematic representation of a mechanical percussion mechanism for a hand-held power tool according to one embodiment; Fig. 3 a schematic representation of an intermediate shaft of the mechanical striking mechanism according to one embodiment; Fig. 4 a schematic representation of a striking body of the striking mechanism according to one embodiment; Fig. 5 a further schematic representation of the striking body of the striking mechanism according to one embodiment; Fig. 6 a schematic representation of a guide groove of an intermediate shaft and / or a striking element of a striking mechanism of the prior art; and Fig. 7 - 9 graphical diagrams of the lifting and striking behavior of a striking mechanism of the prior art and of the striking mechanism according to the invention.

[0051] Fig. Figure 1 shows a schematic representation of a hand-held power tool 200 with a mechanical impact mechanism 100 according to one embodiment.

[0052] In the illustrated embodiment, the hand-held power tool comprises a drive motor 205, a motor shaft 207, a gear unit 209, and a tool holder 203 with an insert tool 201. The hand-held power tool further comprises a percussion mechanism 100 according to the invention, comprising an intermediate shaft 101, an output shaft 105, and a striking element 103. The percussion mechanism 100 is arranged between the gear unit 209 and the tool holder 203. The percussion mechanism 100 is rotatable via the drive motor 205 through the gear unit 209, and the rotation of the percussion mechanism 100 rotatably drives the insert tool 201 arranged in the tool holder 203. The tool holder can be an internal and / or an external mount.

[0053] In one embodiment, the impact mechanism 100 is designed as a rotary impact mechanism. The hand-held power tool 200 is accordingly designed as a rotary impact wrench.

[0054] Fig. Figure 2 shows a schematic representation of a mechanical percussion mechanism 100 for a hand-held power tool 200 according to one embodiment.

[0055] In Fig. Figure 2 schematically shows an interaction of the impact mechanism 100 with the gear unit 209 and the tool holder 203 of the hand-held power tool 200. Fig. 1 shown.

[0056] In the embodiment shown, the striking mechanism 100 comprises the intermediate shaft 101. The intermediate shaft 101 comprises a cylindrical body 149. At least one guide groove 111 is formed on an outer surface 147 of the cylindrical body 149. Spherical guide elements 115 can be slidably arranged in the guide groove 111.

[0057] The striking mechanism 100 further comprises a striking body 103. The striking body 103 comprises a ring body 155 with an axial through-opening 153. Two drive cams 107 are formed on an end face 157 of the ring body 155.

[0058] The percussion mechanism 100 further comprises an output shaft 105. The output shaft 105 comprises a cylindrical body 161 and a base element 159 formed at a free end of the cylindrical body 161. Two output cams 109 are formed on the base element 159.

[0059] In the prior art, the output shaft 105 with the output cams 109 is also called the anvil. The striking body 103 with drive cams 107 is referred to as the hammer. In striking mode, the drive cams 107 of the hammer 103 strike the output cams 109 of the anvil 105.

[0060] In the embodiment shown, the striking mechanism further comprises a bearing unit 133 and a spring element 135.

[0061] The intermediate shaft 101 can be coupled to the transmission unit 209 via corresponding gears. The cylinder body 149 of the intermediate shaft 101 can pass through the bearing unit 133 and the spring element 135 through the through-opening 153 of the impact body 103.

[0062] According to the invention, at least one guide groove 113 is provided on an inner surface 151 of the through-opening 153 of the striking body 103. Fig. 2 not shown, designed. The guide bodies 115 can be rotatably arranged in the guide groove 113. When the intermediate shaft 101 passes through the through-opening 153 of the impact body 103, the intermediate shaft 101 can be rotatably coupled to the output shaft 105. The output shaft 105 can be rotatably inserted into the tool holder 203.

[0063] In the impact mode of the hand-held power tool 200, the intermediate shaft 101 winds the impact body 103 onto it. During this process, the impact body 103 moves axially towards the intermediate shaft 101, rotating circumferentially relative to the intermediate shaft 101. As it winds up, the impact body 103 rotates at a slightly different speed relative to the intermediate shaft 101, performing an axial movement. Once wound up, the impact body 103 executes a rotary impact motion, moving axially and circumferentially. During this motion, the impact body 103 moves towards the tool holder 203, rotating along its circumference. The drive cams 107 of the impact body 103 strike the output cams 109 of the output shaft 105, causing the output shaft 105 to rotate and impact.This causes the impact operation of the hand-held power tool 200 by also setting the insert tool 201 into rotation in an impact manner.

[0064] In the embodiment shown, the impact mechanism 100 further comprises an additional bearing unit 137, which is arranged between the output shaft 105 and the tool holder 203.

[0065] Fig. Figure 3 shows a schematic representation of an intermediate shaft 101 of the mechanical striking mechanism 100 according to one embodiment.

[0066] According to the invention, the intermediate shaft 101 has at least one guide groove 111 for guiding at least one guide body 115. The guide groove 111 has a guide surface 117. The guide surface is formed by an inner surface of the recess through which the guide groove 111 is formed. According to the invention, the guide surface 117 of the guide groove 111 of the intermediate shaft 101 is designed as a crease-free and / or edge-free surface.

[0067] In the illustrated embodiment, the guide groove 111 has a substantially parabolic profile 121. The profile 121 describes a line shape that runs along a longitudinal direction of the guide groove 111. The profile 121 lies within the cylindrical body 149 of the intermediate shaft 101. This can be seen in Figure b). The profile 121 runs along a lowest point of the recess of the guide groove 111.

[0068] The kink-free or edge-free guide surface 117 has no edges or kinks that cross the drawn path 121 of the guide surface 117, as shown in graphics a) and b).

[0069] In the illustrated embodiment, the guide groove 111 further comprises a circumferential line 125. The circumferential line 125 describes an outer edge of the recess through which the guide groove 111 is formed. In the illustrated embodiment, the circumferential line 125 of the guide groove 111 is designed as a kink-free circumferential line 125. As shown in Figures a) and b), the circumferential line 125 has no kinks. Rather, the circumferential line 125 can be represented by a continuously differentiable mathematical function that is continuously differentiable at every point along the circumferential line 125.

[0070] The same applies to the guide surface 117. Since the guide surface 117 also has no kinks or edges at any point, the guide surface 117 can be represented by a two-dimensional mathematical function that is continuously differentiable at every point of its domain.

[0071] According to one embodiment, the mathematical functions by which the circumferential line 125 or the guide surface 117 of the guide groove 111 are represented are at least twice continuously differentiable.

[0072] According to one embodiment, the curvature of the guide groove 111 is smaller than the curvature of the spherical guide body 115. Due to the smaller curvature of the guide groove 111, the guide body 115 is Fig. 3 not shown, can be arranged slidably in the guide groove 111.

[0073] In the illustrated embodiment, the path 121 of the guide surface 117 or the guide groove 111 is mirrored at a reversal point 129. The reversal point 129 is located at the lowest point of the recess of the guide groove 111 on the guide surface 117 and describes a vertex of the guide groove 111, which is essentially parabolic.

[0074] Due to the essentially parabolic shape of the profile 121 of the guide groove 111, the slope of the profile 121 is variable and therefore not constant.

[0075] Figure b) shows an enlarged view of the intermediate shaft 101 from Figure a), where in Figure b) the intermediate shaft is rotated about a longitudinal axis L of the intermediate shaft 101. As indicated in Figure b), the intermediate shaft 101 has two guide grooves 111, each formed on the outer surface 147 of the cylinder body 149.

[0076] According to one embodiment, the two guide grooves 111 of the intermediate shaft 101 are identical in design.

[0077] Fig. Figure 4 shows a schematic representation of a striking body 103 of the striking mechanism 100 according to one embodiment.

[0078] Figure b) shows an enlarged view of the guide groove 113 formed on the inner surface 151 of the through-hole 153 of the ring body 155 of the impact body 103. The representation shown in Figure b) shows the guide groove 113 along the section plane A in Figure a).

[0079] According to the invention, the guide groove 113 has a guide surface 119 which is designed as a crease-free or edge-free surface. Analogous to the guide surface 117 of the guide groove 111 of the intermediate shaft 101, the guide surface 119 in the illustrated embodiment has a substantially parabolic profile 123. The profile 123 lies within the ring body 155 of the impact body 103.

[0080] This is indicated in graphic b) and in Fig. 5 b) shown. The path 123 runs along the lowest point of the recess of the guide groove 111. The guide surface 119 has no edges or kinks that intersect the path 123.

[0081] In the illustrated embodiment, the guide groove 113 also has a circumferential line 127. The circumferential line 127 is also free of kinks.

[0082] In the embodiment shown, the guide surface 119 and the circumferential line 127 of the guide groove 113 can each be represented as continuously differentiable mathematical functions.

[0083] According to one embodiment, the continuously differentiable mathematical functions are at least twice continuously differentiable at every point in their domain of definition.

[0084] According to one embodiment, the curvature of the guide groove 113 of the impact body 103 is smaller than the curvature of the spherically shaped guide bodies 115.

[0085] Analogous to the guide groove 111 of the intermediate shaft 101, the path 123 of the guide groove 113 of the impact body 103 is mirrored at a reversal point 131. The reversal point 131 is located at the lowest point of the recess of the guide groove 113 on the guide surface 119 and describes a vertex of the guide groove 113, which is essentially parabolic.

[0086] The guide grooves 111 of the intermediate shaft 101 and the guide grooves 113 of the striking element 103 can each be identical in design. The guide grooves 111 and 113 can have identical lengths. The length of a guide groove 111 or 113 runs along the path 121 or 123 between endpoints 143 and 145. Endpoints 143 and 145 of the guide grooves 111 and 113 represent the ends of the respective guide grooves 111 and 113. The guide groove 111 of the intermediate shaft 101 has two endpoints 143, and the intermediate shaft 113 of the striking element 103 similarly has two endpoints 145. The guide elements 115 can be guided in the guide grooves 111 and 113 only between the endpoints 143 and 145. Furthermore, the profiles 121, 123 of the guide grooves 111, 113 can have the same slopes.

[0087] In the embodiment shown, the slope of the curve 123 is variable due to the essentially parabolic shape of the curve 123, i.e., it is not constant.

[0088] As indicated in Figure a), the striking body 103 comprises two guide grooves 113, each arranged on the inner surface 151 of the through-opening 153 of the ring body 155. When the intermediate shaft 101 is inserted through the through-opening 153, each spherical guide body 115 is guided by a guide groove 111 of the intermediate shaft 101 and a guide groove 113 of the striking body 103. Due to the guidance of the spherical guide bodies 115 in the essentially parabolic guide grooves 111 and 113, the intermediate shaft 101 and the striking body 103 are rotatable relative to each other about the longitudinal axis L and displaceable along the longitudinal axis L.

[0089] According to one embodiment, the guide groove 113 has a smaller curvature than the spherical guide bodies 115. This allows the spherical guide body 115 to slide or roll in the guide groove 113 of the impact body 103.

[0090] According to one embodiment, the axial movement of the striking body 103 along the path 123 of the guide groove 113 is continuous and not linear with respect to a relative angle α between that of the intermediate shaft 101 and the striking body 103. The relative angle α describes a relative rotation of the intermediate shaft 101 to the striking body 103.

[0091] Fig. Figure 5 shows a further schematic representation of the striking body 103 of the striking mechanism 100 according to one embodiment.

[0092] Graphics a) and b) show sectional views of the striking body 103 of the Fig. 4. The guide grooves 113 are each recessed into the inner surfaces 151 of the through-hole 153.

[0093] Fig. Figure 6 shows a schematic representation of a guide groove 101A of an intermediate shaft 101A and / or a striking body 103A of a striking mechanism of the prior art.

[0094] In the prior art, guide grooves 111A, 113A, which are formed in both intermediate shafts and striking elements of the striking mechanisms known from the prior art, are provided with guide surfaces 117A, 119A that are not kink-free or edge-free. Instead, the Fig. 6 Guide groove 111A, 113A, representative of guide grooves known from the prior art, has three edges 139A which meet at a bend point 147A.

[0095] Edges 139A are formed in the guide surface 117A, 119A and intersect the path 121A, 123A of the guide groove 111A, 113A. Due to edges 139A, the guide surface 117A, 119A cannot be represented by a continuously differentiable mathematical function, as the mathematical function is not differentiable at edges 139A. The same applies to the path 121A, 123A, which is also not differentiable at edge 139A.

[0096] The circumferential line 125A, 127A of the guide groove 111A, 113A also has a kink 141A, which means that the circumferential line 125A, 127A cannot be represented by a continuously differentiable mathematical function in the prior art. Due to the edges 139A of the guide surface 117A, 119A, the guidance of the spherical guide elements within the guide groove 111A, 113A is not as uniform as in the guide grooves 111, 113 of the present invention.

[0097] Instead, the spherical guide bodies 115 experience a sudden movement at the level of the edges 139A of the guide surfaces 117A, 119A, which does not allow for uniform guidance of the guide bodies 115 and causes increased material stress and increased material wear of both the guide bodies 115 and the guide grooves 111A, 113A.

[0098] Fig. Figures 7-9 show graphical diagrams of the lifting and striking behavior of a prior art striking mechanism and of the inventive striking mechanism 100.

[0099] In Fig. In graphs a) to d), axial positions AL of the intermediate shaft 101 and the impact body 103 are shown relative to each other against the relative angle α between the intermediate shaft 101 and the impact body 103.

[0100] In graphs a) and b), this is shown for a start-up phase of the impact operation between 0 and 0.1 seconds. In graphs c) and d), impact operation after the start-up phase is shown for 3.6 to 3.7 seconds. Graphs a) and c) show results for impact mechanisms with guide grooves 111A and 113A, which are known from the prior art and in Fig. Figure 6 is shown. Figures b) and d) show results for a percussion mechanism 100 with guide grooves 111, 113 according to the invention.

[0101] In graphs a) to d) curves are shown for the elevator 141 and the strike 139 between the output shaft 105 and the strike body 103.

[0102] As can be seen from graphs b) and d), the curves of graphs b) and d), i.e. the axial positions AL in relation to the relative angle α, run in a much more ordered and symmetrical form than the percussion mechanism known from the prior art, as shown in graphs a) and c).

[0103] Fig. Figure 8 shows axial velocities V in graphs a) to d). a plotted with respect to the relative angle α between the intermediate shaft 101 and the impact body 103.

[0104] Graphs a) and b) show the start-up phase for times between 0.0 and 0.1 seconds. Graphs c) and d) show results for the hammering operation after the start-up phase for times between 3.6 and 3.7 seconds.

[0105] Figures a) and c) show results for a percussion mechanism known from the prior art. Figures b) and d) show results for the percussion mechanism 100 according to the invention.

[0106] In graphs a) to d) curves are shown for the elevator 141 and the strike 139 between the output shaft 105 and the strike body 103.

[0107] As can be seen from graphs b) and d), the axial velocities V a relative to the relative angle α, the percussion mechanism 100 according to the invention exhibits a significantly more symmetrical and uniform course than the percussion mechanism known from the prior art, as shown in graphs a) and c).

[0108] Fig. Figure 9 shows tangential velocities V in graphs a) to d). t plotted with respect to the relative angle α between the intermediate shaft 101 and the impact body 103.

[0109] Graphs a) and b) show the tangential velocities V t relative to the relative angle α, again for the start-up phase for times between 0.0 and 0.1 seconds.

[0110] In graphs a) to d) curves are shown for the elevator 141 and the strike 139 between the output shaft 105 and the strike body 103.

[0111] Graphs c) and d) show tangential velocities V t for the striking operation after the start-up phase for times between 3.6 and 3.7 seconds. Graphs a) and c) show results for a striking mechanism known from the prior art. Graphs b) and d) show results for the striking mechanism 100 according to the invention.

[0112] As can be seen from graphs b) and d), the tangential velocities V trelative to the relative angle α, the percussion mechanism 100 according to the invention exhibits a significantly more symmetrical and uniform course than the percussion mechanism known from the prior art, as can be seen from graphs a) and c).

[0113] The simulation and measurement results shown in Figures 7 to 9 illustrate that the guide grooves 111, 113 according to the invention, with edge- and kink-free guide surfaces 117, 119, enable significantly more uniform guidance of the guide bodies 115 and the striking body 103. This allows for substantially more energy-efficient and material-friendly operation of the striking mechanism 100 according to the invention, in which axial positions AL and tangential velocities V t and axial velocities V a The intermediate shaft 101 and the impact body 103 can be brought into substantially more harmonious relationships with each other, both during the start-up phase and during impact operation.

Claims

[1] Mechanical impact mechanism (100) for a percussive drive of an insert tool (201) of a hand-held power tool (200), comprising a rotatably mounted intermediate shaft (101), an impact body (103) and a rotatably mounted output shaft (105), wherein the intermediate shaft (101) and the impact body (103) each comprise at least one guide groove (111, 113) for guiding at least one guide body (115), and wherein a guide surface (117) of the guide groove (111) of the intermediate shaft (101) and / or a guide surface (119) of the guide groove (113) of the impact body (103) is designed as a kink-free and / or edge-free surface. [2] Percussion mechanism (100) according to claim 1, wherein the guide groove (111, 113) of the intermediate shaft (101) and / or of the percussion body (103) has a substantially parabolic course (121, 123). [3] Impact mechanism (100) according to claim 1 or 2, wherein a circumferential line (125, 127) of the guide groove (111, 113) of the intermediate shaft (101) and / or of the impact body (103) is formed as a kink-free circumferential line (125, 127). [4] Impact mechanism (100) according to claim 3, wherein the circumferential line (125, 127) and / or the guide surface (117, 119) of the guide groove (111, 113) of the intermediate shaft (101) and / or of the impact body (103) can be represented by a continuously differentiable function. [5] Percussion mechanism (100) according to claim 4, wherein the function is at least twice continuously differentiable. [6] Percussion mechanism (100) according to one of the preceding claims, wherein a curvature of the guide groove (111, 113) is smaller than a curvature of the guide body (115). [7] Percussion mechanism (100) according to one of the preceding claims, wherein the guide body (115) is designed as a ball. [8] Impact mechanism (100) according to one of the preceding claims 2 to 7, wherein the axial movement of the impact body (103) along the course (121, 123) of the guide groove (111, 113) is continuous and non-linear to a relative angle between the intermediate shaft (101) and the impact body (103). [9] Percussion mechanism (100) according to one of the preceding claims 2 to 8, wherein the course (121, 123) of the guide groove (111, 113) of the intermediate shaft (101) and / or of the percussion body (103) is mirrored at a reversal point (129, 131). [10] Impact mechanism (100) according to one of the preceding claims, wherein lengths of the guide grooves (111, 113) of the intermediate shaft (101) and of the impact body (103) are identical or different. [11] Impact mechanism (100) according to one of the preceding claims 2 to 10, wherein the gradients of the courses of the guide grooves (111, 113) of the intermediate shaft (101) and of the impact body (103) are identical to one another or different from one another. [12] Impact mechanism (100) according to one of the preceding claims 2 to 11, wherein the gradients of the courses of the guide grooves (111, 113) of the intermediate shaft (101) and of the impact body (103) are each constant or variable. [13] Percussion mechanism (100) according to one of the preceding claims, the percussion mechanism (100) is designed as a rotary percussion mechanism. [14] Hand tool (200) with a mechanical impact mechanism (100) according to one of the preceding claims 1 to 13. [15] Hand tool (200) according to claim 14, wherein the hand tool (200) is designed as a rotary impact wrench.

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