Mechanical striking 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 well-known from the state of the art. However, a known problem with these impact mechanisms is the high mechanical stress on the components of the impact mechanism.

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

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

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

[0006] This allows for the technical advantage of providing an improved impact mechanism. The kink-free and / or edge-free guide surfaces of the guide grooves allow the guide elements to be guided in the guide grooves with lower energy losses. Furthermore, wear on the guide grooves and the guide elements is reduced.

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

[0008] A guide surface of a guide groove, as defined in the application, is an inner surface of the respective guide groove. When the guide body is guided in the guide groove, the guide body is arranged in 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 part of the recess on which the guide body rests.

[0009] For the purposes of the application, "kink-free" or "edge-free" means that there are no kinks or edges within the guide surfaces. In particular, there are no edges or kinks in the guide surfaces that cross the guideways of the guide bodies, which they form when guided in the guide grooves.

[0010] In the state of the art, the impact body is also called a percussion hammer or rotary percussion 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 the technical advantage to be achieved that the parabolic shape of the guide grooves allows the guide bodies to be guided in the most energy-optimized way possible.

[0013] The profile of the guide groove refers to a longitudinal direction of the guide groove. The profile of the guide groove defines the guide path followed by the guide body when the guide body is guided through the guide groove. The profile is essentially parabolic. This means that a deviation from the exact parabolic shape is 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 through 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 the technical advantage of generating optimally kink-free and edge-free guide surfaces of 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 the predefined range.

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

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

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

[0023] This provides the technical advantage that the guide bodies can be guided in the guide grooves with as little friction as possible.

[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] According to one embodiment, the guide body is designed as a ball.

[0026] This provides the technical advantage that the guide bodies can be guided in the guide grooves with as little friction as possible.

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

[0028] This can achieve the technical advantage of achieving the most energy-efficient guidance of the guide bodies in the guide grooves, in which the energy losses of the guidance of the guide bodies within the guide grooves are minimized.

[0029] The terms "continuous" and "nonlinear" are to be understood mathematically. The course of the guide groove is thus the course of a mathematically continuous and nonlinear function.

[0030] The relative angle describes an angle of relative rotation of the intermediate shaft and the impact body to each other.

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

[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 provides the technical advantage that the symmetrical shape of the guide grooves ensures symmetrical guidance of the guide bodies within the guide grooves. This symmetrical guidance, in turn, is energy-efficient, with energy losses minimized as much as possible.

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

[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 provides the technical advantage of adapting the guide grooves to specific requirements. The lengths can be adjusted to the radii of the intermediate shaft and the impact body, allowing the guide bodies to be guided as evenly as possible in the guide grooves.

[0037] The length of a guide groove runs between the end points of the guide groove. The length runs along the guide groove's contour. The end points are defined by the guide groove's circumference.

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

[0039] This makes it possible to achieve the technical advantage that the courses 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 the application, a gradient is a mathematical gradient of a mathematical function.

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

[0042] This makes it possible to achieve the technical advantage that the courses 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] According to one embodiment, the percussion mechanism is designed as a rotary percussion mechanism.

[0045] This provides 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 according to one of the preceding embodiments is provided.

[0047] This makes it possible to achieve the technical advantage that an improved hand-held power tool with an improved impact force can be provided with the technical advantages described above.

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

[0049] This can achieve 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 shows a schematic representation of a handheld power tool with a mechanical percussion mechanism according to one embodiment; Fig. 2 shows a schematic representation of a mechanical percussion mechanism for a handheld power tool according to one embodiment; Fig. 3 shows a schematic representation of an intermediate shaft of the mechanical percussion mechanism according to one embodiment; Fig. 4 shows a schematic representation of an impact body of the percussion mechanism according to one embodiment; Fig. 5 shows a further schematic representation of the impact body of the percussion mechanism according to one embodiment; Fig. 6 shows a schematic representation of a guide groove of an intermediate shaft and / or an impact body of a percussion mechanism of the prior art; and Figs. 7 - 9 show graphic diagrams of the winding and impact behavior of a percussion mechanism of the prior art and of the percussion mechanism according to the invention.

[0051] Fig. 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 embodiment shown, the handheld 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 handheld power tool further comprises an impact mechanism 100 according to the invention with an intermediate shaft 101, an output shaft 105, and an impact body 103. The impact mechanism 100 is arranged between the gear unit 209 and the tool holder 203. The impact mechanism 100 is rotatable via the drive motor 205 via the gear unit 209, wherein the insert tool 201 arranged in the tool holder 203 can be driven in rotation via the rotation of the impact mechanism 100. The tool holder can be an internal holder and / or an external holder.

[0053] According to one embodiment, the impact mechanism 100 is designed as a rotary impact mechanism. The handheld power tool 200 is correspondingly designed as a rotary impact wrench.

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

[0055] In Fig. 2 is a schematic illustration of the interaction of the impact mechanism 100 with the gear unit 209 and the tool holder 203 of the hand-held power tool 200 from 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 bodies 115 can be slidably arranged in the guide groove 111.

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

[0058] The percussion mechanism 100 further comprises an output shaft 105. The output shaft 105 comprises a cylinder body 161 and a base element 159 formed at a free end of the cylinder 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 impact body 103 with the drive cams 107 is referred to as the hammer. During impact operation, the drive cams 107 of the hammer 103 thus 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 gear unit 209 via corresponding gears. The cylinder body 149 of the intermediate shaft 101 can be passed through the bearing unit 133 and the spring element 135 through the through-opening 153 of the impact body 103.

[0062] On an inner surface 151 of the through-opening 153 of the impact body 103, according to the invention, at least one guide groove 113 is provided, in Fig. 2 not shown. The guide bodies 115 can be arranged rotatably in the guide groove 113. When the intermediate shaft 101 is passed 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] During impact operation of the hand-held power tool 200, the intermediate shaft 101 winds up the impact body 103. The impact body 103 moves axially in the direction of the intermediate shaft 101 and rotates around the circumferential direction towards the intermediate shaft 101. During winding, the impact body 103 rotates at a slightly different speed towards the intermediate shaft 101 and performs an axial movement. Once the impact body 103 is wound up, the impact body 103 performs a rotary impact movement in which the impact body 103 is moved axially and in the circumferential direction. The impact body 103 is moved towards the tool holder 203 and performs a rotary movement along the circumferential direction. 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 in an impacting manner.This causes the impact operation of the hand-held power tool 200 by also causing the insert tool 201 to rotate in an impact manner.

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

[0065] Fig. 3 shows a schematic representation of an intermediate shaft 101 of the mechanical impact mechanism 100 according to an 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. The guide surface 117 of the guide groove 111 of the intermediate shaft 101 is designed according to the invention as a kink-free and / or edge-free surface.

[0067] In the embodiment shown, the guide groove 111 has a substantially parabolic profile 121. The profile 121 describes a linear shape that runs along a longitudinal direction of the guide groove 111. The profile 121 lies within the cylinder body 149 of the intermediate shaft 101. This can be seen in graphic b). The profile 121 runs at a deepest point of the recess of the guide groove 111.

[0068] According to graphics a) and b), the kink-free or edge-free guide surface 117 has no edges or kinks that cross the drawn course 121 of the guide surface 117.

[0069] In the embodiment shown, the guide groove 111 further has 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 embodiment shown, the circumferential line 125 of the guide groove 111 is designed as a kink-free circumferential line 125. As shown in graphics 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 on 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 in its domain of definition.

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

[0073] In the embodiment shown, the profile 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 a lowest point of the recess of the guide groove 111 on the guide surface 117 and describes an apex of the essentially parabolic guide groove 111.

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

[0075] Graphic b) shows an enlarged view of the intermediate shaft 101 of graphic a), wherein in graphic b) the intermediate shaft is rotated about a longitudinal axis L of the intermediate shaft 101. As indicated in graphic 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 of identical construction.

[0077] Fig. 4 shows a schematic representation of an impact body 103 of the impact mechanism 100 according to an embodiment.

[0078] Graphic b) shows an enlarged view of the guide groove 113 formed on the inner surface 151 of the through-opening 153 of the annular body 155 of the impact body 103. The illustration shown in graphic b) shows the guide groove 113 along the section plane A in graphic a).

[0079] According to the invention, the guide groove 113 has a guide surface 119 that is designed as a kink-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 annular body 155 of the impact body 103.

[0080] This is indicated in graph b) and in Fig. 5 b) shown. The path 123 runs at a deepest point of the recess of the guide groove 111. The guide surface 119 has no edges or kinks that cross the path 123.

[0081] In the embodiment shown, the guide groove 113 further has a circumferential line 127. The circumferential line 127 is also designed to be kink-free.

[0082] In the embodiment shown, the guide surface 119 and the circumferential line 127 of the guide groove 113 can each be represented by 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, a curvature of the guide groove 113 of the impact body 103 is smaller than a curvature of the spherically shaped guide bodies 115.

[0085] Analogous to the guide groove 111 of the intermediate shaft 101, the profile 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 a deepest point of the recess of the guide groove 113 on the guide surface 119 and describes an apex of the essentially parabolic guide groove 113.

[0086] The guide grooves 111 of the intermediate shaft 101 and the guide grooves 113 of the impact body 103 can each be structurally identical to one another. The guide grooves 111, 113 can have identical lengths. The length of a guide groove 111, 113 runs along the path 121, 123 between end points 143, 145. End points 143, 145 of the guide grooves 111, 113 represent the ends of the respective guide grooves 111, 113. The guide groove 111 of the intermediate shaft 101 has two end points 143, and the intermediate shaft 113 of the impact body 103 similarly has two end points 145. The guide bodies 115 can be guided in the guide grooves 111, 113 at most between the end points 143, 145. Furthermore, the courses 121, 123 of the guide grooves 111, 113 can have the same gradients.

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

[0088] As indicated in graphic a), the impact body 103 comprises two guide grooves 113, each arranged on the inner surface 151 of the through-opening 153 of the annular 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 impact body 103. By guiding the spherical guide bodies 115 in the essentially parabolic guide grooves 111, 113, the intermediate shaft 101 and the impact body 103 are rotatable relative to one another 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 body 115. As a result, the spherical guide body 115 is arranged so as to be slidable or rollable in the guide groove 113 of the impact body 103.

[0090] According to one embodiment, the axial movement of the impact body 103 along the course 123 of the guide groove 113 is continuous and non-linear to a relative angle α between that of the intermediate shaft 101 and the impact body 103. The relative angle α describes a relative rotation of the intermediate shaft 101 to the impact body 103.

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

[0092] The graphics a) and b) show sectional views of the impact body 103 of the Fig. 4 .

[0093] The guide grooves 113 are each recessed into the inner surfaces 151 of the through opening 153.

[0094] Fig. 6 shows a schematic representation of a guide groove 101A of an intermediate shaft 101A and / or an impact body 103A of a prior art impact mechanism.

[0095] From the prior art, guide grooves 111A, 113A, which are formed both in intermediate shafts and impact bodies of the impact mechanisms known from the prior art, are provided with guide surfaces 117A, 119A, which are not designed to be free of kinks or edges. Instead, the guide grooves 111A, 113A, which are formed in Fig. 6 The guide groove 111A, 113A, which is representative of guide grooves known from the prior art, has three edges 139A which meet at a kink point 147A.

[0096] The edges 139A are formed in the guide surface 117A, 119A and intersect the profile 121A, 123A of the guide groove 111A, 113A. Due to the edges 139A, the guide surface 117A, 119A cannot be represented by a continuously differentiable mathematical function, since the mathematical function is not differentiable at the edges 139A. The same applies to the profile 121A, 123A, which is also not differentiable at the edge 139A.

[0097] 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 bodies within the guide groove 111A, 113A is not as uniform as it is in the guide grooves 111, 113 of the present invention.

[0098] Instead, the spherical guide bodies 115 experience a sudden movement at the level of the edges 139A of the guide surfaces 117A, 119A, which prevents 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.

[0099] Fig. 7 - 9 show graphic diagrams of a winding and striking behavior of a striking mechanism of the prior art and of the striking mechanism 100 according to the invention.

[0100] In Fig. 7 In graphics a) to d) axial positions AL of the intermediate shaft 101 and the impact body 103 relative to each other are plotted against the relative angle α between the intermediate shaft 101 and the impact body 103.

[0101] 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), an impact operation after the start-up phase for 3.6 to 3.7 seconds is shown. The graphs a) and c) show results for impact mechanisms with guide grooves 111A, 113A, which are known from the state of the art and in Fig. 6 are shown. Graphs b) and d) show results for a percussion mechanism 100 with guide grooves 111, 113 according to the invention.

[0102] In the graphs a) to d) curves for the lift 141 and the impact 139 between the output shaft 105 and the impact body 103 are shown.

[0103] 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 orderly and symmetrical form than the percussion mechanism known from the state of the art, as shown in graphs a) and c).

[0104] Fig. 8 shows in the graphs a) to d) axial velocities V a plotted in relation to the relative angle α between the intermediate shaft 101 and the impact body 103.

[0105] Figures a) and b) again show the start-up phase for times between 0.0 and 0.1 seconds. Figures c) and d) show results for impact operation after the start-up phase for times between 3.6 and 3.7 seconds.

[0106] Figures a) and c) again show results for a prior art percussion mechanism. Figures b) and d) show results for the percussion mechanism 100 according to the invention.

[0107] In the graphs a) to d) curves for the lift 141 and the impact 139 between the output shaft 105 and the impact body 103 are shown.

[0108] As can be seen from graphs b) and d), the axial velocities V a relative to the relative angle α for the impact mechanism 100 according to the invention show a significantly more symmetrical and uniform course than the impact mechanism known from the prior art, as shown in graphs a) and c).

[0109] Fig. 9 shows in the graphs a) to d) tangential velocities V t plotted in relation to the relative angle α between the intermediate shaft 101 and the impact body 103.

[0110] The 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.

[0111] In the graphs a) to d) curves for the lift 141 and the impact 139 between the output shaft 105 and the impact body 103 are shown.

[0112] Graphs c) and d) show tangential velocities V t for impact operation after the start-up phase for times between 3.6 and 3.7 seconds. Graphs a) and c) show results for a prior art impact mechanism. Graphs b) and d) show results for the inventive impact mechanism 100.

[0113] As can be seen from graphs b) and d), the tangential velocities V t relative to the relative angle α for the impact mechanism 100 according to the invention show a significantly more symmetrical and uniform course than the impact mechanism known from the prior art, as can be seen from graphs a) and c).

[0114] The simulation and measurement results shown in Figures 7 to 9 illustrate that the inventive guide grooves 111, 113 with edge- and kink-free guide surfaces 117, 119 enable a significantly more uniform guidance of the guide bodies 115 and the impact body 103. This enables a substantially more energy-efficient and material-friendly operation of the inventive impact mechanism 100, in which the axial positions AL, tangential velocities V t , and axial velocities V a of the intermediate shaft 101 and the impact body 103 relative to one another can be achieved with substantially more harmonious curves both in 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. Impact mechanism (100) according to claim 1, wherein the guide groove (111, 113) of the intermediate shaft (101) and / or of the impact 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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