Mechanical impact mechanism
By adopting the design of foldless and edgeless guide surfaces and parabolic guide grooves in the mechanical impact mechanism of the rotary impact wrench, the problem of high mechanical load in the prior art is solved, and more efficient energy transfer and lower wear are achieved. .
Patent Information
- Application Number
- CN202411125041.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-08-18
- Filing Date
- 2024-08-16
- Publication Date
- 2025-02-21
AI Technical Summary
The mechanical impact mechanism of existing rotary impact wrench has problems with high mechanical load, resulting in increased component wear and increased energy loss.
A mechanical impact mechanism for a handheld tool machine is designed, adopting a rotatably supported intermediate shaft and driven shaft. The guide groove of the intermediate shaft and the impact body has a guide surface without folding and edgeless, and the direction of the guide groove. It is basically parabolic in shape to optimize the guide path of the guide body.
Through the design of the guide surface without folding and edgeless guide surface and parabolic guide groove, the energy loss and wear of the guide body in the guide groove are reduced, and the energy efficiency and material friendliness of the impact mechanism are improved.
Smart Images
Figure CN119489409A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a mechanical impact mechanism for a handheld power tool, in particular a rotary impact wrench. Background 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 loads on the components of the impact mechanism. Summary of the invention
[0003] The object of the present invention is to provide an improved mechanical impact mechanism for a hand-held power tool.
[0004] The object is achieved by an impact mechanism of a preferred technical solution. Advantageous designs are the subject of an optional technical solution.
[0005] According to one aspect, a mechanical impact mechanism for an impact drive of an insert tool of a handheld power tool is provided, comprising a rotatably supported intermediate shaft, an impact body and a rotatably supported driven shaft, wherein the intermediate shaft and the impact body each comprise at least one guide groove for guiding at least one guide body, wherein the guide surface of the guide groove of the intermediate shaft and / or the guide surface of the guide groove of the impact body are constructed as non-bend and / or non-edge surfaces.
[0006] This can achieve the technical advantage of providing an improved impact mechanism. Due to the non-bend and / or non-edge guide surface of the guide groove, the guidance of the guide body in the guide groove can reduce energy losses. In addition, the wear of the guide groove and the guide body can be reduced.
[0007] In the sense of the present application, a guide groove is a groove section which determines the coupling of the axial displacement with the relative rotation of the impact body and the intermediate shaft in the working region.
[0008] In the sense of the present application, the guide surface of a guide groove is the inner surface of the corresponding 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 in which the guide body is located.
[0009] In the meaning of the present application, no fold or no edge refers to no fold or edge formed inside the guide surface. Particularly, when the guide body is guided in the guide groove, no edge or fold is formed in the guide surface intersecting with the guide path of the guide body.
[0010] In the prior art, the impact body is also called an impact hammer or a rotary impact hammer.
[0011] According to one embodiment, the guide groove of the intermediate shaft and / or of the striking body has an essentially parabolic course.
[0012] The technical advantage achieved thereby is that the parabolic course of the guide groove in turn enables the guide body to be guided in an energy-optimized manner.
[0013] The direction of the guide groove relates to the longitudinal direction of the guide groove. When the guide body is guided by the guide groove, the direction of the guide groove defines the guide path implemented by the guide body. This direction is basically parabolic. This means that it can deviate from the exact parabolic shape.
[0014] According to one embodiment, the circumferential line of the guide groove of the intermediate shaft and / or the impact body is designed as a kink-free circumferential line.
[0015] The technical advantage achieved thereby is that the guide surface is designed as a smooth guide surface without kinks or edges.
[0016] The circumference of the guide groove describes the outer edge of the recess, by which the guide groove is defined.
[0017] According to one embodiment, the circumferential line of the intermediate shaft and / or the impact body and / or the guide surface of the guide groove can be mapped by a continuously differentiable function.
[0018] The technical advantage achieved thereby is that an optimally kink-free and edge-free guide surface of the guide groove can be achieved.
[0019] A continuously differentiable function is a mathematical function that is differentiable within a predetermined range and whose derivative within the predetermined range is a continuous function.
[0020] According to one embodiment, the function is successively differentiable at least twice.
[0021] The technical advantage achieved thereby is that an optimally kink-free and edge-free guide surface of the guide groove can be achieved.
[0022] According to one embodiment, the curvature of the guide groove is smaller than the curvature of the guide body.
[0023] The technical advantage achieved thereby is that the guide body is guided in the guide groove with the lowest possible friction.
[0024] The curvature of the guide groove is the curvature of the guide groove recess perpendicular to the direction of the guide groove.
[0025] According to one embodiment, the guide body is designed as a ball.
[0026] The technical advantage achieved thereby is that the guide body is guided in the guide groove with the lowest possible 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 the relative angle between the striking body and the intermediate shaft.
[0028] The technical advantage achieved thereby is that a guide body guidance which is as energy-efficient as possible is achieved in the guide groove, wherein energy losses of the guide body in the guide groove are minimized.
[0029] The terms continuous and nonlinear are to be understood from a mathematical point of view. Thus, the course of the guide groove is the course of a mathematically continuous and nonlinear function.
[0030] The relative angle describes the relative rotation angle of the intermediate shaft and the impact body.
[0031] In this case, the impact body does not perform a purely axial movement, but always also a rotational movement. This refers to the axial part of the spiral movement performed by the impact body.
[0032] According to one embodiment, the course of the guide grooves of the intermediate shaft and / or of the impact body is mirrored at the reversal point.
[0033] The technical advantage achieved thereby is that, due to the symmetrical shape of the guide groove, a symmetrical guidance of the guide body in the guide groove is achieved. The symmetrical guidance in turn minimizes energy losses and thus increases energy efficiency.
[0034] In this case, the reversal point is formed by the vertex of the essentially parabolic course.
[0035] According to one embodiment, the guide grooves of the intermediate shaft and the impact body have the same or different lengths.
[0036] The technical advantage that can be achieved thereby is that the guide groove can be adjusted as required. Here, the length can be adapted to the radius of the intermediate shaft and the impact body, so that the guide body can be guided in the guide groove as evenly as possible.
[0037] Here, the length of the guide groove extends between the end points of the guide groove. Here, the length extends along the direction of the guide groove. The end points are respectively determined 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 to each other.
[0039] The technical advantage achieved thereby is that the slope of the guide groove can be adapted to the design of the intermediate shaft and the impact body, for example to the radius of the intermediate shaft and the impact body, in order to achieve the most energy-efficient possible guidance of the guide body in the guide groove.
[0040] In the sense of the present application, a slope is the mathematical slope of a mathematical function.
[0041] According to one specific embodiment, the slope of the course of the guide grooves of the intermediate shaft and of the impact body is respectively constant or variable.
[0042] The technical advantage achieved thereby is that the course of the guide groove can be adapted to the design of the intermediate shaft and the impact body, for example to the radius of the intermediate shaft and the impact body, in order to achieve the most energy-efficient possible guidance of the guide body in the guide groove.
[0043] A constant slope is the slope of a linear mathematical function. A variable slope is the non-constant slope of a non-linear function.
[0044] According to one embodiment, the impact mechanism is designed as a rotary impact mechanism.
[0045] The technical advantage achieved thereby is that an improved rotary striking mechanism can be provided.
[0046] According to one aspect, a handheld power tool is provided having a mechanical impact mechanism according to one of the above-described embodiments.
[0047] The technical advantage achieved thereby is that an improved handheld power tool having an improved impact mechanism with the above-mentioned technical advantages is provided.
[0048] According to one embodiment, the handheld power tool is designed as a rotary impact wrench.
[0049] The technical advantage achieved thereby is that an improved rotary impact wrench is provided. BRIEF DESCRIPTION OF THE DRAWINGS
[0050] The embodiments of the present invention are described with reference to the following drawings. In the drawings:
[0051] Figure 1 A schematic diagram showing a handheld power tool with a mechanical impact mechanism according to one embodiment;
[0052] Figure 2 A schematic diagram showing a mechanical impact mechanism for a handheld power tool according to one embodiment;
[0053] Figure 3 A schematic diagram showing an intermediate shaft of a mechanical impact mechanism according to one embodiment;
[0054] Figure 4 A schematic diagram showing an impact body of an impact mechanism according to one embodiment;
[0055] Figure 5 Another schematic diagram showing an impact body of an impact mechanism according to one embodiment;
[0056] Figure 6 A schematic diagram showing a guide groove of an intermediate shaft and / or an impact body of an impact mechanism in the prior art; and
[0057] Figure 7-9Schematic diagram showing the lifting and impact behavior of a percussion mechanism according to the prior art and of the percussion mechanism according to the invention. DETAILED DESCRIPTION
[0058] Figure 1 A schematic illustration of a handheld power tool 200 with a mechanical impact mechanism 100 according to one specific embodiment is shown.
[0059] In the illustrated embodiment, the handheld power tool comprises a drive motor 205, a motor shaft 207, a transmission unit 209, and a tool receiving portion 203 with an inserted tool 201. The handheld power tool further comprises an impact mechanism 100 according to the present invention, which has an intermediate shaft 101, a driven shaft 105, and an impact body 103. The impact mechanism 100 is arranged between the transmission unit 209 and the tool receiving portion 203. The impact mechanism 100 can be rotated by the drive motor 205 via the transmission unit 209, wherein the inserted tool 201 arranged in the tool receiving portion 203 is rotatably driven by the rotation of the impact mechanism 100. The tool receiving portion can be an inner receiving portion and / or an outer receiving portion.
[0060] According to one embodiment, the impact mechanism 100 is designed as a rotary impact mechanism. Accordingly, the handheld power tool 200 is designed as a rotary impact wrench.
[0061] Figure 2 A schematic diagram of a mechanical impact mechanism 100 for a handheld power tool 200 according to one specific embodiment is shown.
[0062] Figure 2 The impact mechanism 100 is schematically shown Figure 1 The interaction between the transmission unit 209 and the tool receiver 203 of the handheld power tool 200 is shown.
[0063] In the illustrated embodiment, the impact mechanism 100 includes an intermediate shaft 101. The intermediate shaft 101 includes a cylindrical body 149. At least one guide groove 111 is formed on an outer surface 147 of the cylindrical body 149. A spherical guide body 115 is slidably arranged in the guide groove 111.
[0064] The impact mechanism 100 further includes an impact body 103. The impact body 103 includes an annular body 155, and the annular body 155 has an axial through-opening 153. Two driving cams 107 are formed on an end surface 157 of the annular body 155.
[0065] The impact mechanism 100 further comprises a driven shaft 105. The driven shaft 105 comprises a cylindrical body 161 and a base element 159 configured at a free end of the cylindrical body 161. Two driven projections 109 are configured on the base element 159.
[0066] In the prior art, the driven shaft 105 with the driven cam 109 is also called an anvil. The impact body 103 with the driving cam 107 is called a hammer. In the impact operation, the driving cam 107 of the hammer 103 impacts the driven cam 109 of the anvil 105.
[0067] In the embodiment shown, the impact mechanism further comprises a bearing unit 133 and a spring element 135 .
[0068] The intermediate shaft 101 can be coupled to the transmission unit 209 via corresponding gears. The cylindrical body 149 of the intermediate shaft 101 can pass through the bearing unit 133 , and the spring element 135 can pass through the through-opening 153 of the impact body 103 .
[0069] According to the present invention, at least one guide groove 113 is formed on the inner surface 151 of the through opening 153 of the impact body 103. Figure 2 The guide body 115 is 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 driven shaft 105. The driven shaft 105 can be rotatably inserted into the tool receiving portion 203.
[0070] During the impact operation of the handheld power tool 200, the intermediate shaft 101 lifts (or pulls up) the impact body 103. Here, the impact body 103 moves axially in the direction of the intermediate shaft 101 and performs a rotation in the circumferential direction toward the intermediate shaft 101. Therefore, during the lifting, the impact body 103 rotates at a slightly changed rotation speed relative to the intermediate shaft 101 and performs an axial movement. If the impact body 103 is lifted, it performs a rotary impact movement in which it moves in the axial and circumferential directions. Here, the impact body 103 moves in the direction of the tool receptacle 203 and performs a rotary movement in the circumferential direction. Here, the driving cam 107 of the impact body 103 strikes the driven cam 109 of the driven shaft 105, thereby causing the driven shaft 105 to rotate in an impact manner. As a result, the impact operation of the handheld power tool 200 is caused in that the inserted tool 201 also rotates in an impact manner.
[0071] In the embodiment shown, the striking mechanism 100 also has a further bearing unit 137 which is arranged between the output shaft 105 and the tool receiver 203 .
[0072] Figure 3A schematic diagram of an intermediate shaft 101 of a mechanical impact mechanism 100 according to one embodiment is shown.
[0073] According to the present 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 a hollow inner surface forming the guide groove 111. According to the present invention, the guide surface 117 of the guide groove 111 of the intermediate shaft 101 is formed as a surface without folds (or transitions) and / or edges.
[0074] In the embodiment shown, the guide groove 111 has a substantially parabolic course 121. The course 121 describes a line shape along the longitudinal direction of the guide groove 111. The course 121 is located in the cylindrical body 149 of the intermediate shaft 101. This can be seen in FIG. b). The course 121 extends to the deepest part of the recess of the guide groove 111.
[0075] According to FIGS. a) and b), the fold-free or edge-free guide surface 117 has no edges or folds intersecting the drawn course 121 of the guide surface 117 .
[0076] In the embodiment shown, the guide groove 111 also has a circumferential line 125. The circumferential line 125 describes the outer edge of the recessed space forming the guide groove 111. In the embodiment shown, the circumferential line 125 of the guide groove 111 is formed as a circumferential line 125 without folds (or jumps). As shown in a) and b), the circumferential line 125 has no folds (or jumps). On the contrary, the circumferential line 125 can be represented by a continuously differentiable mathematical function, which is continuously differentiable at each point of the circumferential line 125.
[0077] The same is true for the guide surface 117. Since the guide surface 117 has no folds or edges at any point, the guide surface 117 can be represented by a two-dimensional mathematical function, which is continuously differentiable at every point in its domain.
[0078] According to one embodiment, the mathematical function representing the circumference line 125 of the guide groove 111 or the guide surface 117 can be continuously differentiated at least twice.
[0079] According to one embodiment, the curvature of the guide groove 111 is smaller than the curvature of the spherical guide body 115. Since the curvature of the guide groove 111 is smaller, the guide body 115 ( Figure 3 ) can be slidably arranged in the guide groove 111.
[0080] In the embodiment shown in the figures, the course 121 of the guide surface 117 or the guide groove 111 is mirrored at the 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 represents the vertex of the substantially parabolic guide groove 111.
[0081] Since the course 121 of the guide groove 111 is substantially parabolic in shape, the slope (or gradient) of the course 121 is variable and therefore not constant.
[0082] FIG. b) shows an enlarged view of the intermediate shaft 101 of FIG. a), wherein in FIG. b), the intermediate shaft rotates around the longitudinal axis L of the intermediate shaft 101. As shown in FIG. b), the intermediate shaft 101 has two guide grooves 111, which are respectively formed on the outer surface 147 of the cylindrical body 149.
[0083] According to one embodiment, the two guide grooves 111 of the intermediate shaft 101 have the same structure.
[0084] Figure 4 A schematic diagram of an impact body 103 of an impact mechanism 100 according to one embodiment is shown.
[0085] FIG. b) shows an enlarged view of the guide groove 113 formed on the inner surface 151 of the through-opening 153 of the annular main body 155 of the impact body 103. The illustration in FIG. b) shows the guide groove 113 along the section A in FIG. a).
[0086] According to the invention, the guide groove 113 has a guide surface 119 which is designed as a surface without folds or edges. Similar to the guide surface 117 of the guide groove 111 of the intermediate shaft 101, the guide surface 119 has a substantially parabolic course 123 in the embodiment shown. The course 123 is located in the annular body 155 of the impact body 103.
[0087] This is shown in Figure b) and Figure 5 b). The direction 123 extends to the deepest part of the recess of the guide groove 111. The guide surface 119 does not have any edges or folds intersecting with the direction 123.
[0088] In the embodiment shown, the guide groove 113 also has a circumferential line 127. The circumferential line 127 is also designed without folds.
[0089] In the illustrated embodiment, the guide surface 119 and the circumferential line 127 of the guide groove 113 can be represented by continuously differentiable mathematical functions, respectively.
[0090] According to one embodiment, a continuously differentiable mathematical function is continuously differentiable at least twice at every point of its domain.
[0091] According to one embodiment, the curvature of the guide groove 113 of the impact body 103 is smaller than the curvature of the spherical guide body 115 .
[0092] Similar to the guide groove 111 of the intermediate shaft 101, the course 123 of the guide groove 113 of the impact body 103 is mirrored at the 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 represents the vertex of the substantially parabolic guide groove 113.
[0093] The guide groove 111 of the intermediate shaft 101 and the guide groove 113 of the impact body 103 can be designed to be structurally identical to each other. In this case, the guide grooves 111, 113 can have the same length. The length of the guide grooves 111, 113 extends along the direction 121, 123 between the end points 143, 145. The 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 also has two end points 145. The guide body 115 can be guided in the guide grooves 111, 113 at most between the end points 143, 145. In addition, the directions 121, 123 of the guide grooves 111, 113 can have the same slope.
[0094] In the illustrated embodiment, since the course 123 is substantially parabolic, the slope of the course 123 is variable, ie, not constant.
[0095] As shown in FIG. a), the impact body 103 includes two guide grooves 113, which are respectively arranged on the inner surface 151 of the through-hole 153 of the annular body 155. When the intermediate shaft 101 is inserted into the through-hole 153, each spherical guide body 115 is guided by the guide groove 111 of the intermediate shaft 101 and the guide groove 113 of the impact body 103. By guiding the spherical guide body 115 in the substantially parabolic guide grooves 111, 113, the intermediate shaft 101 and the impact body 103 can rotate relative to each other around the longitudinal axis L and can move along the longitudinal axis L.
[0096] According to one embodiment, the curvature of the guide groove 113 is smaller than the curvature of the spherical guide body 115 , so that the spherical guide body 115 can slide or roll in the guide groove 113 of the impact body 103 .
[0097] According to one embodiment, the axial movement of the impact body 103 along the path 123 of the guide groove 113 is continuous and nonlinear with respect to the relative angle α between the intermediate shaft 101 and the impact body 103. The relative angle α describes the relative rotation of the intermediate shaft 101 relative to the impact body 103.
[0098] Figure 5 Another schematic illustration of an impact body 103 of an impact mechanism 100 according to one embodiment is shown.
[0099] Figures a) and b) show Figure 4 103. The guide grooves 113 are respectively processed in the inner surface 151 of the through opening 153.
[0100] Figure 6 A schematic diagram of a guide groove 101A of an intermediate shaft 101A and / or an impact body 103A of an impact mechanism according to the prior art is shown.
[0101] In the prior art, the guide grooves 111A, 113A formed in the intermediate shaft and the impact body of the impact mechanism known from the prior art are provided with guide surfaces 117A, 119A, which are not formed without folds or edges. Figure 6 The guide groove 111A, 113A shown is representative of guide grooves known in the prior art and has three edges 139A that intersect at a kink 147A.
[0102] These edges 139A are formed in the guide surfaces 117A, 119A and intersect with the directions 121A, 123A of the guide grooves 111A, 113A. Due to these edges 139A, the guide surfaces 117A, 119A cannot be represented by a continuously differentiable mathematical function, because the mathematical function in the edges 139A is not differentiable. The same is true for the directions 121A, 123A, which are also not differentiable at the edges 139A.
[0103] The circumferential lines 125A, 127A of the guide grooves 111A, 113A also have folds 141A, so in the prior art, the circumferential lines 125A, 127A cannot be represented by a continuously differentiable mathematical function. Due to the edges 139A of the guide surfaces 117A, 119A, the guiding of the spherical guide body in the guide grooves 111A, 113A is not as uniform as in the guide grooves 111, 113 of the present invention.
[0104] In contrast, the spherical guide body 115 undergoes abrupt movement at the height of the edge 139A of the guide surfaces 117A, 119A, which makes it impossible to achieve uniform guidance of the guide body 115 and leads to increased material load and increased material wear not only of the guide body 115 but also of the guide grooves 111A, 113A.
[0105] Figure 7-9 Schematic diagram showing the lifting and impact behavior of an impact mechanism according to the prior art and an impact mechanism 100 according to the present invention.
[0106] exist Figure 7 , Figures a) to d) show the relationship between the axial position AL of the intermediate shaft 101 and the impact body 103 relative to each other and the relative angle α between the intermediate shaft 101 and the impact body 103.
[0107] The start-up phase of the impact operation is shown in Figures a) and b) for a period of 0 to 0.1 seconds. Figures c) and d) show the impact operation after the start-up phase for a period of 3.6 to 3.7 seconds. Figure 6 Figures b) and d) show the results of an impact mechanism 100 with guide grooves 111, 113 according to the invention.
[0108] Graphs a) to d) each show the course of a lift 141 and an impact 139 between output shaft 105 and impact body 103 .
[0109] As can be seen from Figures b) and d), the curves in Figures b) and d), ie the axial position AL with respect to the relative angle α, are more ordered and more symmetrical than the impact mechanisms known in the prior art (as shown in Figures a) and c).
[0110] Figure 8 The axial velocity V plotted in Figures a) to d) is shown a The relationship with the relative angle α between the intermediate shaft 101 and the impact body 103.
[0111] Graphs a) and b) again show the start-up phase, between 0.0 and 0.1 seconds. Graphs c) and d) show the results of the impact run after the start-up phase, between 3.6 and 3.7 seconds.
[0112] Graphs a) and c) also show the results of a percussion mechanism known from the prior art. Graphs b) and d) show the results of a percussion mechanism 100 according to the invention.
[0113] Graphs a) to d) show the curves of the lift 141 and the impact 139 between the output shaft 105 and the impact body 103 , respectively.
[0114] As can be seen from Figures b) and d), compared with the impact mechanism known in the prior art (as shown in Figures a) and c), the axial speed V of the impact mechanism 100 according to the present invention is a The curve with respect to the relative angle α is more symmetrical and more uniform.
[0115] Fig. 9The tangential velocity V plotted in Figures a) to d) is shown t The relationship with the relative angle α between the intermediate shaft 101 and the impact body 103.
[0116] Graphs a) and b) again show the tangential velocity V during the start-up phase relative to the relative angle α. t , the time is between 0.0 seconds and 0.1 seconds.
[0117] Graphs a) to d) show the curves of the lift 141 and the impact 139 between the output shaft 105 and the impact body 103 , respectively.
[0118] Graphs a) to d) show the curves of the lift 141 and the impact 139 between the output shaft 105 and the impact body 103 , respectively.
[0119] As can be seen from Figures b) and d), compared with the impact mechanism known in the prior art, the axial speed V of the impact mechanism 100 of the present invention is a The curves with respect to the relative angle α are more symmetrical and uniform, as shown in (a) and (c).
[0120] Fig. 9 The tangential velocity V plotted in Figures a) to d) is shown t The relationship with the relative angle α between the intermediate shaft 101 and the impact body 103.
[0121] Figures a) and b) show the tangential velocity V relative to the relative angle α. t , also in the startup phase, the time is between 0.0 seconds and 0.1 seconds.
[0122] Graphs a) to d) show the curves of the lift 141 and the impact 139 between the output shaft 105 and the impact body 103 , respectively.
[0123] Graphs c) and d) show the tangential velocity Vt of the impact operation after the start-up phase, between 3.6 and 3.7 seconds. Graphs a) and c) show the results of an impact mechanism known from the prior art. Graphs b) and d) show the results of an impact mechanism 100 according to the invention.
[0124] As can be seen from Figures b) and d), compared with the impact mechanism known in the prior art, the tangential velocity V of the impact mechanism 100 of the present invention is t The curves with respect to the relative angle α are more symmetrical and uniform, as shown in a) and c).
[0125] Figures 7 to 9The simulation results and measurement results shown in show that the guide grooves 111 and 113 of the present invention have guide surfaces 117 and 119 without edges and folds, which can significantly improve the guiding uniformity of the guide body 115 and the impact body 103. This makes the operation of the impact mechanism 100 of the present invention significantly more energy-efficient and material-friendly. In the impact mechanism of the present invention, the axial position AL and the tangential velocity V of the intermediate shaft 101 and the impact body 103 relative to each other are t and axial speed V a Both during the start-up phase and during the impact run, there is a significantly more harmonious curve.
Claims
1. A mechanical impact mechanism (100) for an impact drive of an insertion tool (201) of a handheld power tool (200), comprising a rotatably supported intermediate shaft (101), an impact body (103) and a rotatably supported 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), 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) are configured as surfaces without kinks and / or edges.
2. The impact mechanism (100) according to claim 1, wherein: The guide grooves (111, 113) of the intermediate shaft (101) and / or of the impact body (103) have a substantially parabolic course (121, 123).
3. The impact mechanism (100) according to claim 1 or 2, wherein: The circumferential line (125, 127) of the guide groove (111, 113) of the intermediate shaft (101) and / or the impact body (103) is configured as a kink-free circumferential line (125, 127).
4. The impact mechanism (100) according to claim 3, wherein: The circumferential lines (125, 127) and / or the guide surfaces (117, 119) of the guide grooves (111, 113) of the intermediate shaft (101) and / or the impact body (103) can be mapped by a continuously differentiable function.
5. The impact mechanism (100) according to claim 4, wherein: The function is capable of being continuously differentiated at least twice.
6. The impact mechanism (100) according to one of the preceding claims, wherein: The curvature of the guide grooves (111, 113) is smaller than the curvature of the guide body (115).
7. The impact mechanism (100) according to one of the preceding claims, wherein: The guide body (115) is designed as a ball.
8. The impact mechanism (100) according to any one of the preceding claims 2 to 7, wherein: The axial movement of the impact body (103) along the direction (121, 123) of the guide groove (111, 113) is continuous and nonlinear relative to the relative angle between the intermediate shaft (101) and the impact body (103).
9. The impact mechanism (100) according to any 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 the impact body (103) is mirror-imaged at the reversal point (129, 131).
10. The impact mechanism (100) according to one of the preceding claims, wherein: The lengths of the guide grooves (111, 113) of the intermediate shaft (101) and the impact body (103) are the same or different.
11. The impact mechanism (100) according to any one of the preceding claims 2 to 10, wherein: The slopes of the guide grooves (111, 113) of the intermediate shaft (101) and the impact body (103) are the same as or different from each other.
12. The impact mechanism (100) according to any one of the preceding claims 2 to 11, wherein: The slopes of the guide grooves (111, 113) of the intermediate shaft (101) and the impact body (103) are respectively constant or variable.
13. The impact mechanism (100) according to one of the preceding claims, wherein: The impact mechanism (100) is designed as a rotary impact mechanism.
14. A hand-held power tool (200) having a mechanical impact mechanism (100) according to any one of the preceding claims 1 to 13.
15. The handheld power tool (200) according to claim 14, wherein: The hand-held power tool (200) is designed as a rotary impact wrench.