Method and device for machining a cylinder liner

Abstract

Method for machining a cylinder liner (9) as a separate component of an internal combustion engine, wherein firstly the unmachined cylinder liner (9) is clamped in a clamping step by means of a clamping device (39; 73) in such a way that by means of the clamping device (39; 73) clamping forces (F Sp ) are exerted on the cylinder liner (9), wherein, in a subsequent machining step, the running surface (29) of the cylinder liner (9) clamped by means of the clamping device (39; 73) is machined by means of a machining device (41) in such a way that at least one bulge (31, 35) of the running surface (29) projecting inwards into a piston receiving space (30) of the cylinder liner (9) is removed by means of the machining device (41), wherein, when clamping the cylinder liner (9), the cylinder liner (9) is first brought into planar contact with a clamping element (47; 75) of the clamping device (39; 73) with a supporting wall region (13) facing away from an upper end wall (11) of the cylinder liner (9), wherein at least one clamping element (47; 75) and the cylinder liner (9) each have an externally visible marking (99, 101) as an indication for an arrangement of the cylinder liner (9) in a defined rotational position relative to the clamping element (47; 75), wherein a further clamping element (55; 81) of the clamping device (39; 73) is subsequently brought into flat contact with the upper end wall (11) of the cylinder liner (9), and wherein finally, by means of a pressing device (61; 95) of the clamping device (39; 73), at least one of the clamping elements (47, 55; 75, 81) is pressed and / or pushed against the cylinder liner (9), and wherein the cylinder liner (9) is formed by a downstop liner, and wherein the clamping element (47; 75) has a receiving space (49; 83) in which the cylinder liner (9) can be arranged at least in sections, wherein at least one wall region (53; 85) of the clamping element (47; 75) delimiting the receiving space (49; 83) forms a guide for the cylinder liner (9) arranged in the receiving space (49; 83) transversely to the vertical axis direction (z), in such a way that a displacement of the cylinder liner (9) arranged in the receiving space (49; 83) relative to the clamping element (47; 75) in the transverse axis direction (y) and in the longitudinal axis direction (x) and a rotation of the cylinder liner (9) arranged in the receiving space (49; 83) relative to the clamping element (47; 75) about a transverse axis running in the transverse axis direction (y) and about a longitudinal axis running in the longitudinal axis direction (x) is prevented.

Description

[0001] The invention relates to a method for machining a cylinder liner as a separate component of an internal combustion engine according to patent claim 1 and to a device for machining a cylinder liner as a separate component of an internal combustion engine according to patent claim 9.

[0002] Cylinder liners, which are designed as a separate component or as an assembly element of an internal combustion engine, and also so-called integrated cylinder liners, which are cast into a crankcase of an internal combustion engine and are thus an integral part of the crankcase, are generally known.

[0003] To assemble a cylinder liner designed as a separate component of an internal combustion engine, the cylinder liner is usually first inserted into a liner receiving space in a crankcase of the internal combustion engine until the cylinder liner, with a radially outwardly projecting support wall area, comes into contact with a support wall area of the crankcase. If this support wall area is arranged in an upper area of the cylinder liner, viewed in the axial direction of the liner, the cylinder liner is usually referred to as a top-stop liner. If the annular support wall area is arranged in a middle area of the cylinder liner, the cylinder liner is usually referred to as a mid-stop liner. If the annular support wall area is arranged in a lower area of the cylinder liner, the cylinder liner is usually referred to as a down-stop liner.An example of a downstop cylinder liner is disclosed in DE 10 2009 059 057 A1.

[0004] After inserting the cylinder liner into the liner receiving space of the crankcase, the crankcase is then usually bolted to the cylinder head of the internal combustion engine. In order to achieve a gas- and pressure-tight seal between the cylinder head and the cylinder liner, the cylinder head is bolted to the crankcase in such a way that the cylinder head exerts a high preload force on the cylinder liner resting on the support wall area on the crankcase side. This preload force, acting in the axial direction of the liner, and also the screw connections themselves cause a deformation of the cylinder liner, which creates bulges that protrude radially inward into a piston receiving space in the cylinder liner. These bulges have a negative effect on the movement and sealing of a piston in the cylinder liner.These bulges can lead to increased lubricant consumption in the internal combustion engine and increased wear on the cylinder liner and the associated piston. This is particularly true for midstop liners and downstop liners, where the distance between the upper end wall of the cylinder liner and the supporting wall area in contact with the crankcase is relatively large, thus causing even greater deformation of the cylinder liner.

[0005] WO 2004 / 022 284 A1 discloses a clamping device of a fine machining device and a method for deformation-adapted fine machining of a workpiece using the clamping device. DE 10 2007 015 153 A1 discloses a fine machining method and a fine machining machine for fine machining workpieces clamped during fine machining. DE 10 2005 042 639 A1 discloses a device and a method for fine machining a workpiece. DE 28 10 322 C2 discloses a honing machine. JP H11-267 960 A discloses a hole machining device.

[0006] The object of the invention is therefore to provide a method and a device for machining a cylinder liner as a separate component of an internal combustion engine, by means of which the friction between the cylinder liner and an associated piston as well as the lubricant requirement of the internal combustion engine can be reduced effectively and easily.

[0007] This problem is solved by the features of the independent patent claims. Preferred developments are disclosed in the subclaims.

[0008] According to claim 1, a method for machining a cylinder liner as a separate component of an internal combustion engine is claimed. When the internal combustion engine is assembled, this cylinder liner is in an assembly clamping state in which the cylinder liner is subjected to clamping forces and thus clamped. To machine the cylinder liner, the unmachined and unassembled cylinder liner is first clamped in a clamping step using a clamping device in such a way that the clamping device exerts clamping forces on the cylinder liner that at least approximately correspond to the assembly clamping state of the cylinder liner.Subsequently, in a machining step, the running surface of the cylinder liner clamped by means of the clamping device is machined by means of a machining device, in particular having a honing tool, in particular in such a way that bulges of the running surface projecting inwards into a piston receiving space of the cylinder liner are removed by means of the machining device.

[0009] In this way, the friction between the cylinder liner and an associated piston is effectively and easily reduced because the machining of the running surface of the cylinder liner, in particular the final machining of the running surface, now takes place in a state of the cylinder liner that corresponds at least approximately to the assembly clamping position of the cylinder liner. This ensures that, in the assembled state of the internal combustion engine, the running surface of the cylinder liner has the desired contour, in particular without bulges protruding into the piston receiving space. This also improves the sealing of the piston, which also reduces the lubricant consumption of the internal combustion engine. Overall, the efficiency of the internal combustion engine is therefore significantly increased by the method according to the invention.

[0010] In a preferred method according to the invention, the running surface of the cylinder liner is machined such that the cylinder liner, viewed in a cross-section transverse to the liner's axial direction, has a circular running surface contour along the entire cylinder bore. Further preferably, the running surface of the cylinder running surface is also machined such that the cylinder liner, viewed in cross-section in the axial direction, has a rectilinear running surface contour along the entire cylinder bore. Overall, it is therefore particularly preferred if the piston receiving space of the cylinder liner has a cylindrical shape in order to optimally adapt the piston receiving space to the cylindrical piston that can be arranged therein and thus to be able to operate the internal combustion engine particularly efficiently.

[0011] In a preferred specific embodiment, the machining device for machining the running surface of the cylinder liner has a cutting tool, preferably a honing tool, particularly preferably a honing tool, in order to be able to machine the running surface of the clamped cylinder liner simply and effectively.

[0012] It is advantageous if the clamping forces acting on the cylinder liner in the assembled clamping state are determined by means of a clamping force determination device. This allows the cylinder liner to be clamped simply and effectively according to its assembled clamping state. Preferably, the clamping forces acting on the cylinder liner in the assembled clamping state are determined by computer simulation and / or by means of a sensor system, in particular by means of at least one strain gauge, of the clamping force determination device. When using a strain gauge, the strain gauge can first be attached to the unassembled cylinder liner. The cylinder liner is then mounted together with the strain gauge attached to it. When the cylinder liner or the internal combustion engine is assembled, the deformation of the cylinder liner is then measured using the attached strain gauge.

[0013] It is also advantageous if the clamping device has an adjustment device by means of which the clamping forces exerted on the clamped cylinder liner by the clamping device are adjusted, in particular independently or automatically, depending on the clamping forces determined by the clamping force determination device. This allows the cylinder liner to be clamped simply and effectively according to the assembly clamping state. Preferably, the clamping device has an input device connected to the adjustment device for signaling purposes, by means of which the clamping forces determined by the clamping force determination device are entered, in particular manually.

[0014] According to the invention, when clamping the cylinder liner, the cylinder liner is first brought into surface contact with a clamping element of the clamping device, in particular a clamping element that is fixed in a fixed position, with a supporting wall region facing away from an upper end wall of the cylinder liner. Subsequently, another clamping element of the clamping device is brought into surface contact with the upper end wall of the cylinder liner. According to the invention, at least one of the clamping elements is then pressed or pushed against the cylinder liner, in particular against the upper end wall and / or against the supporting wall region of the cylinder liner, by means of a pressing device of the clamping device. In this way, the cylinder liner can be clamped simply and effectively, at least approximately in accordance with the assembly clamping state.

[0015] According to the invention, at least one clamping element and the cylinder liner each have an externally visible marking indicating an arrangement of the cylinder liner in a defined rotational position relative to the clamping element. This allows, for example, the cylinder liner to be easily and reliably arranged in a defined rotational position relative to the clamping element when clamped by means of the clamping device. This effectively ensures that the cylinder liner, when clamped by means of the clamping device, is arranged in a defined rotational position relative to the at least one clamping element, in particular relative to screw connections for connecting the clamping elements.If a crankcase of the internal combustion engine also has a corresponding marking, it can be easily and effectively ensured that the cylinder liner, in the assembled state of the internal combustion engine, is arranged in the same rotational position relative to the screw connections for connecting the crankcase to the cylinder head and is thus clamped in an identical manner as with the clamping device according to the invention.

[0016] To achieve the above-mentioned object, a device for machining a cylinder liner as a separate component of an internal combustion engine is further claimed, comprising a clamping device by means of which the unmachined cylinder liner can be clamped in such a way that the clamping device exerts clamping forces on the cylinder liner that correspond at least approximately to an assembly clamping state of the cylinder liner, and comprising a machining device, in particular a machining device having a honing tool, by means of which the running surface of the cylinder liner clamped by means of the clamping device can be machined, in particular in such a way that bulges of the running surface that project inwards into a piston receiving space of the cylinder liner clamped by means of the clamping device can be removed by means of the machining device.

[0017] The advantages resulting from the device according to the invention are identical to the already appreciated advantages of the method according to the invention, so that they are not repeated here.

[0018] In a preferred specific embodiment of the device according to the invention, the clamping device has a first clamping element which, when the cylinder liner is clamped, is in contact, in particular over a surface, with an upper end wall of the cylinder liner. The clamping device then also has a second, in particular stationary, clamping element which, when the cylinder liner is clamped, is in contact, in particular over a surface, with a support wall region of the cylinder liner facing away from the upper end wall. The cylinder liner can thus be clamped simply and effectively, at least approximately in accordance with the assembly clamping state. It is preferred if the support wall region, in particular annular, of the clampable cylinder liner is arranged in a lower and / or central region of the cylinder liner, viewed in the axial direction of the liner. With such a midstop orThe machining of a cylinder liner according to the invention is particularly effective for a downstop liner. The lower, middle, and upper regions of the cylinder liner can be divided in the axial direction of the liner such that each of these regions has a height of one-third of the length or height of the entire cylinder liner.

[0019] Preferably, the first clamping element has a continuous, in particular cylindrical, recess through which a machining tool, in particular a honing tool, of the machining device can be passed when the clamping device is in the clamped state, in particular with a defined gap spacing. It is particularly preferred if the first clamping element is substantially annular and / or tubular in order to design the first clamping element in a simple and functionally optimized manner.

[0020] According to the invention, the second clamping element has a receiving space, in particular a cylindrical one, in which the cylinder liner can be arranged at least in sections, in particular at least with a lower end region, wherein at least one wall region of the second clamping element delimiting the receiving space forms a guide for the cylinder liner arranged in the receiving space transversely to the vertical axis direction of the device. By means of this guide, a displacement of the cylinder liner arranged in the receiving space relative to the second clamping element in the transverse axis direction and in the longitudinal axis direction as well as a rotation of the cylinder liner arranged in the receiving space relative to the second clamping element about a transverse axis running in the transverse axis direction and about a longitudinal axis running in the longitudinal axis direction is prevented.By means of such a clamping element, the cylinder liner can be easily and permanently arranged in its intended position. Preferably, the second clamping element is substantially annular and / or tubular in order to design the second clamping element in a simple and functionally optimized manner.

[0021] The clamping device further preferably comprises a pressing device by means of which at least one of the clamping elements for clamping the cylinder liner can be pressed and / or pushed against the cylinder liner, in particular against the end wall and / or against the at least one supporting wall region of the cylinder liner. Using such a pressing device, the cylinder liner can be clamped simply and effectively, at least approximately corresponding to the assembly clamping state.

[0022] In a preferred specific embodiment, it is provided that the second clamping element is fixed in place, and that the pressing device has an actuating element, in particular an actuating arm, connected or connectable to the first clamping element, by means of which the first clamping element can be pressed against the cylinder liner. In principle, this actuating element can be actuated, for example, by a person, in particular manually. However, it is preferred if the actuating element can be actuated by means of a drive device, in particular a hydraulic one.

[0023] Alternatively, the pressing device can also be formed by several screw connections by means of which the clamping elements can be connected to one another, wherein the clamping elements can be pressed against the cylinder liner by means of the screws of the screw connections. This allows the cylinder liner to be clamped particularly effectively according to the assembly clamping state of the cylinder liner. Preferably, it is provided that, in the clamped state of the clamping device, the clamping elements connected by means of the screw connections are in contact with one another, in particular over a large area.

[0024] The advantageous embodiments and / or further developments of the invention explained above and / or reproduced in the subclaims can be used individually or in any combination with one another - except, for example, in cases of clear dependencies or incompatible alternatives.

[0025] The invention and its advantageous embodiments and / or further developments as well as their advantages are explained in more detail below with reference to drawings merely by way of example.

[0026] They show: Fig. 1 shows a sectional view of the assembly state of a cylinder liner; Fig. 2 in a further sectional view the assembly state of the cylinder liner; Fig. 3 shows a schematic sectional view of a first embodiment of a device according to the invention with the cylinder liner in the unmachined state; Fig. 4 in a representation according to Fig. 4 the cylinder liner in the machined state; Fig. 5 in a representation according to Fig. 1 the cylinder liner in the machined state; Fig. 6 shows a schematic sectional view of a second embodiment of a device according to the invention; Fig. 7 in a representation according to Fig. 2 the cylinder liner in the machined state; and Fig. 8 in a view from above the device without a first clamping element.

[0027] In Fig. 1 shows a part of an internal combustion engine 1 in the assembled state in a schematic sectional view. The internal combustion engine 1 has a crankcase 3 and a cylinder head 5, which are connected to one another by means of several screw connections 7. In addition, the internal combustion engine 1 also has a cylinder liner 9 as a separate component of the internal combustion engine 1, which is in an unmachined state here. The cylinder liner 9 is essentially tubular and, in the assembled state of the internal combustion engine 1, has an upper end wall 11, viewed in the liner axial direction x, in flat contact with the cylinder head 5 or with a cylinder head gasket (not shown here) arranged between the crankcase 3 and the cylinder head 5.In addition, in the assembled state of the internal combustion engine 1, the cylinder liner 9 also has a support wall region 13 facing away from the upper end wall 11 in planar contact with a support wall region 15 of the crankcase. The support wall region 13 is formed here, for example, by the underside of a radially outwardly projecting annular web 17 of the cylinder liner 9. The support wall region 15 is formed here by the upper side of an annular web 21 projecting inward into a cylinder liner receiving space 19 of the crankcase 3.

[0028] The support wall region 13 is arranged further in a lower region 23 of the cylinder liner 9, so that the cylinder liner 9 is formed here by a so-called downstop liner. Furthermore, the cylinder liner 9 is formed here, for example, by a so-called wet cylinder liner 9, which, in the assembled state of the internal combustion engine 1, forms a coolant channel 25 through which a coolant can flow. To form this coolant channel 25, which is annular in this case, an outer wall 26 of the cylinder liner 9 has a circumferential recess 27 between the upper end wall 11 and the support wall region 13, as viewed in the axial direction x.

[0029] As can be seen from the Fig. 1 in the axial direction of the liner, a piston running surface 29 of the unmachined cylinder liner 9, in the assembled state of the internal combustion engine 1, has a bulge or curvature 31 projecting radially inward into a piston receiving chamber 30. This bulge 31 is located in a cylinder running track 33 of the cylinder liner 9 and has a negative effect on the friction between the cylinder liner 9 and the associated piston (not shown here), as well as on the lubricant consumption of the internal combustion engine 1. The bulge 31 is caused primarily by the preload force exerted by the cylinder head 5 on the cylinder liner 9, with which a pressure-tight and gas-tight seal between the cylinder head 5 and the cylinder liner 9 is achieved.

[0030] As can be seen from the Fig. 2, the running surface 29 of the unmachined cylinder liner 9, in the assembled state of the internal combustion engine 1, also has a plurality of bulges 35 projecting radially inwards into the piston receiving chamber 30. These bulges 35 have an identical, negative effect on the efficiency of the internal combustion engine 1. Each of these bulges 35 is located in the area of a screw connection 7 of the assembled internal combustion engine 1 and is caused by the clamping forces emanating from the respective screw connection 7 and acting on the cylinder liner. The closer the screw connections 7 are arranged to the cylinder liner 9, the higher the clamping forces exerted on the cylinder liner 9 by means of the screw connections 7 are.

[0031] In the Fig. 1 and Fig. 2 schematically shows the assembled clamping state of the cylinder liner 9. In the unassembled or unclamped state, the unmachined cylinder liner 9 does not have the bulges 31, 35. The clamping forces acting on the cylinder liner 9 in the assembled clamping state can be, for example, Fig. 1 strain gauge 36 indicated by dashed lines of a clamping force determination device not shown here.

[0032] In Fig. 3 schematically shows a device 37 for machining the cylinder liner 9. This device 37 has a clamping device 39, by means of which the cylinder liner 9 can be clamped in such a way that the clamping device 39 exerts clamping forces on the cylinder liner 9 that at least approximately correspond to the assembled clamping state of the cylinder liner 9. Specifically, the cylinder liner 9 can be clamped here in such a way that the bulge 31 is created as in the assembled clamping state of the unmachined cylinder liner 9. In addition, the device 37 also has a machining device 41, by means of which the running surface 29 of the cylinder liner 9 clamped by means of the clamping device 39 can be machined. The machining device 41 has a machining tool, formed here by way of example by a honing tool 43, by means of which the bulge 31 of the clamped cylinder liner 9 can be removed.The machining of the running surfaces 29 of the cylinder liner 9 by means of the honing tool 43 also represents the final machining of the running surface 29, so that the running surface 29 is honed along the entire cylinder bore 33 by means of the machining device 41.

[0033] In Fig. 3, the cylinder liner 9 is shown in the unmachined state clamped by the clamping device 39. The running surface 29 of the cylinder liner 9 still has the bulge 31. In Fig. 4, the cylinder liner 9 is shown in the state clamped by means of the clamping device 39 and machined by means of the machining device 41. In this state, the cylinder liner 9 no longer has a bulge 31. In the Fig. 4, the running surface 29 of the cylinder liner 9 thus has a straight running surface contour 45 along the entire cylinder bore 33.

[0034] By removing the bulge 31 when the cylinder liner 9 is clamped by means of the clamping device 39, it is achieved that the bulge 31 is no longer present even when the internal combustion engine 1 is assembled. This is Fig. 5 is shown schematically, which shows the assembled state of the internal combustion engine 1 with machined cylinder liner 9. Here, too, the running surface 29 of the cylinder liner 9 has a straight running surface contour 45 along the entire cylinder bore 33.

[0035] How next Fig. 3, the clamping device 39 has an annular or tubular clamping element 47, which, in the clamped state of the cylinder liner 9, has an upper end wall 48 in planar contact with the support wall region 13 of the cylinder liner 9. The clamping element 47 is fixed in place, for example. In addition, the tubular clamping element 47 forms a cylindrical receiving space 49, in which the cylinder liner 9 is arranged or received with a lower end region 51. An inner wall 53 of the clamping element 53, which delimits the receiving space 49, has only a slightly larger diameter than the end region 51 of the cylinder liner 9 and thus forms a guide for the cylinder liner 9 arranged in the receiving space 49, transversely to the vertical axis direction z of the device 37.This prevents a displacement of the cylinder liner 9 arranged in the receiving space 49 relative to the clamping element 47 in the transverse axis direction y and in the longitudinal axis direction x, as well as a rotation of the cylinder liner 9 arranged in the receiving space 49 relative to the clamping element 47 about a transverse axis running in the transverse axis direction y and about a longitudinal axis running in the longitudinal axis direction x.

[0036] Furthermore, the clamping device 39 also has another clamping element 55, which is also tubular, for example, and which, when the cylinder liner 9 is clamped in place, has a lower end wall 57 in planar contact with the upper end wall 11 of the cylinder liner 9. The tubular clamping element 55 forms a continuous cylindrical recess 59 through which the honing tool 43 can be passed.

[0037] According to Fig. 3, the clamping device 39 also has a pressing device 61, by means of which the upper clamping element 55 can be pressed or pushed downwards against the upper end wall 11 of the cylinder liner 9 in the vertical axis direction z for clamping the cylinder liner 9. Clamping forces F acting in the liner axial direction x are then applied via the clamping element 55. Sp exerted on the cylinder liner 9. The pressing device 61 here has, for example, an actuating arm 63 connected to the clamping element 55, by means of which the clamping element 55 can be pressed against the cylinder liner 9. The actuating element 63 can be actuated by means of a schematically indicated, preferably hydraulic, drive device 65 of the pressing device 61. According to Fig. 3, this drive device 65 is also part of an adjustment device 67 of the device 37, by means of which the clamping forces F exerted on the cylinder liner 9 by means of the clamping device 39 Sp can be adjusted independently or automatically depending on the clamping forces determined by the aforementioned clamping force determination device. The clamping forces determined by the clamping force determination device can be manually entered into an input device 69 connected to the setting device 67 via signaling.

[0038] In Fig. 6, a second embodiment of the invention is shown as device 71. In comparison to the device shown in Fig. 3, this device 71 has a different clamping device 73. The device 71 also has the processing device 41, although this is not shown here. By means of the Fig. The clamping device 73 shown in Figure 6 is intended to simulate the assembly clamping state of the cylinder liner 9 as accurately as possible.

[0039] The clamping device 73 has a tubular clamping element 75, which is shown in Fig. 6, the cylinder liner 9 is clamped, with an upper end wall 77 in flat contact with a lower end wall 79 of another, here also tubular, clamping element 81 of the clamping device 73. The clamping element 75 thereby simulates the crankcase 3 of the internal combustion engine 1. The clamping element 81 simulates the cylinder head 5 of the internal combustion engine 1.

[0040] The tubular clamping element 75 forms a substantially cylindrical receiving space 83 in which, when the cylinder liner 9 is clamped, substantially the entire cylinder liner 9 is arranged or received. An inner wall 85 of the clamping element 75 delimiting the receiving space 83 has a diameter only slightly larger than that of the cylinder liner 9 at the lower web 17 and at an outwardly projecting upper web 87 forming the end wall 11, and thus forms a guide for the cylinder liner 9 arranged in the receiving space 83 transversely to the vertical axis direction z of the device 71.This prevents displacement of the cylinder liner 9 arranged in the receiving space 83 relative to the clamping element 75 in the transverse axis direction y and in the longitudinal axis direction x, as well as rotation of the cylinder liner 9 arranged in the receiving space 83 relative to the clamping element 75 about a transverse axis running in the transverse axis direction y and about a longitudinal axis running in the longitudinal axis direction x. In the clamped state, the cylinder liner, with the support wall region 13, is in planar contact with a support wall region 89 of the clamping element 75. This support wall region 89 is formed here by the upper side of an annular web 91 of the clamping element 75 that projects inward into the receiving space 83. Furthermore, in the clamped state, the cylinder liner 9, with the upper end wall 11, is in planar contact with the lower end wall 79 of the clamping element 81.In addition, the tubular clamping element 81 forms a continuous cylindrical recess 93 through which the machining tool of the machining device 41 can be passed when the clamping device 73 is in the clamped state. Furthermore, the clamping element 75 is fixed in position here.

[0041] According to Fig. 6, the clamping device 73 also has a pressing device formed by a plurality of screw connections 95. The clamping elements 75, 81 of the clamping device 73 are connected to one another by means of the screw connections 95, so that the clamping elements 75, 81 are pressed or pushed against the upper end wall 11 and the supporting wall area 13 of the cylinder liner 9 by means of the screws 97 of the screw connections 95, just as in the assembled state of the internal combustion engine 1. The number of screw connections 95 and the arrangement of the screw connections 95 relative to the cylinder liner 9 here corresponds to the number and arrangement of the screw connections 7 in the assembled state of the internal combustion engine 1.

[0042] By means of the clamping device 73, the unmachined cylinder liner 9 can thus be clamped in such a way that, as in the assembled clamping state of the unmachined cylinder liner 9, both the bulge 31 ( Fig. 1) as well as the bulges 35 ( Fig. 2) are present. When clamped by the clamping device 73, both the bulge 31 and the bulges 35 of the running surface 29 can be removed by the machining device 41. In the assembled state of the internal combustion engine 1, the bulges 31, 35 are then no longer present.

[0043] In the Fig. 6 and Fig. 7 shows the cylinder liner 9 as an example in the state machined by means of the machining device 41 and clamped by means of the clamping device 73. In Fig. 6, the running surface 29 of the cylinder liner 9 has a straight running surface contour 45 along the entire cylinder bore 33. In the Fig. In the cross section shown in Fig. 7 transverse to the liner axial direction x, the running surface 29 of the cylinder liner 9 has a circular running surface contour 97.

[0044] Further in Fig. 8 shows the clamping element 75 and the cylinder liner 9 inserted into the receiving space 83 of the clamping element 75 in a top view. This shows that the clamping element 75 and the cylinder liner 9 each have an externally visible marking 99, 101 as an indication for an arrangement of the cylinder liner 9 in a defined rotational position relative to the clamping element 75. This allows, for example, the cylinder liner 9 to be easily and effectively arranged in a defined rotational position relative to the clamping element 75 before clamping by means of the clamping device 71. This ensures that the cylinder liner 9, when clamped by means of the clamping device 71, is arranged in a defined rotational position relative to the clamping element 75 and thus also to the screw connections 95.A corresponding marking (not shown here) is then also provided on the crankcase 3 of the internal combustion engine 1, by means of which the cylinder liner 9 is arranged in the same rotational position relative to the screw connections 7 of the internal combustion engine 1 as to the screw connections 95 of the clamping device 73. This ensures that wear areas 103 of the cylinder liner 9, on which the circumferentially distributed bulges 35 (. Fig. 2) of the running surface 29 are removed, are arranged in the assembled state of the internal combustion engine 1 in the region of a screw connection 7 of the internal combustion engine 1. In the assembled state of the internal combustion engine 1, the cylinder liner 9 is thus clamped in the same way as when clamped by means of the clamping device 73. The markings 85, 87 are arrow-shaped and triangular, respectively, for example. List of reference symbols 1 internal combustion engine 3 cylinder crankcase 5 cylinder head 7 Screw connection 9 Cylinder liner 11 upper front wall 13 Retaining wall area 15 System wall area 17 jetty 19 Cylinder liner receiving space 21 jetty 23 lower area 25 Coolant channel 26 Exterior wall 27 Deepening 29 Tread 30 piston receiving chamber 31 bulge 33 Cylinder bore 35 bulge 36 strain gauges 37 Device 39 clamping device 41 Processing device 43 Honing tool 45 Tread contour 47 clamping element 48 upper front wall 49 Recording room 51 End area 53 Interior wall 55 clamping element 57 lower bulkhead 59 Recess 61 Pressing device 63 Actuating element 65 Drive device 67 Adjustment device 69 Input device 71 Device 73 clamping device 75 clamping element 77 upper front wall 79 lower bulkhead 81 clamping element 83 Recording Room 85 interior wall 87 upper bridge 89 Support wall area 91 jetty 93 Recess 95 screw connection 97 Tread contour 99 Mark 101 Marking 103 Editing area F Sp Tension

Claims

[1] Method for machining a cylinder liner (9) as a separate component of an internal combustion engine, wherein firstly the unmachined cylinder liner (9) is clamped in a clamping step by means of a clamping device (39; 73) in such a way that by means of the clamping device (39; 73) clamping forces (F Sp ) are exerted on the cylinder liner (9), wherein, in a subsequent machining step, the running surface (29) of the cylinder liner (9) clamped by means of the clamping device (39; 73) is machined by means of a machining device (41) in such a way that at least one bulge (31, 35) of the running surface (29) projecting inwards into a piston receiving space (30) of the cylinder liner (9) is removed by means of the machining device (41), wherein, when clamping the cylinder liner (9), the cylinder liner (9) is first brought into planar contact with a clamping element (47; 75) of the clamping device (39; 73) with a supporting wall region (13) facing away from an upper end wall (11) of the cylinder liner (9), wherein at least one clamping element (47; 75) and the cylinder liner (9) each have an externally visible marking (99, 101) as an indication for an arrangement of the cylinder liner (9) in a defined rotational position relative to the clamping element (47; 75), wherein a further clamping element (55; 81) of the clamping device (39; 73) is subsequently brought into flat contact with the upper end wall (11) of the cylinder liner (9), and wherein finally, by means of a pressing device (61; 95) of the clamping device (39; 73), at least one of the clamping elements (47, 55; 75, 81) is pressed and / or pushed against the cylinder liner (9), and wherein the cylinder liner (9) is formed by a downstop liner, and wherein the clamping element (47; 75) has a receiving space (49; 83) in which the cylinder liner (9) can be arranged at least in sections, wherein at least one wall region (53; 85) of the clamping element (47; 75) delimiting the receiving space (49; 83) forms a guide for the cylinder liner (9) arranged in the receiving space (49; 83) transversely to the vertical axis direction (z), in such a way that a displacement of the cylinder liner (9) arranged in the receiving space (49; 83) relative to the clamping element (47; 75) in the transverse axis direction (y) and in the longitudinal axis direction (x) and a rotation of the cylinder liner (9) arranged in the receiving space (49; 83) relative to the clamping element (47; 75) about a transverse axis running in the transverse axis direction (y) and about a longitudinal axis running in the longitudinal axis direction (x) is prevented. [2] Method according to claim 1,characterized by that the running surface (29) of the cylinder liner (9) is machined in such a way that the cylinder liner (9), seen in cross-section transverse to the axial direction (x), has a circular running surface contour (97) along the entire cylinder bore (33). [3] Method according to claim 1 or 2, characterized by that the running surface (29) of the cylinder liner (9) is machined in such a way that the cylinder liner (9), seen in cross-section in the axial direction (x), has a straight running surface contour (45) along the entire cylinder bore (33). [4] Method according to one of the preceding claims, characterized by that a machining device (41) for machining the running surface (29) of the cylinder liner (9) has a cutting tool (43), preferably a honing tool, particularly preferably a honing tool. [5] Method according to one of the preceding claims, characterized bythat the clamping forces (F Sp ) are determined by means of a clamping force determining device (36), wherein it is preferably provided that these clamping forces (F Sp ) by computer simulation and / or by means of a sensor, in particular by means of at least one strain gauge. [6] Method according to claim 5, characterized by that the clamping device (39) has an adjusting device (67) by means of which the clamping forces (F Sp) are adjusted, in particular automatically, as a function of the clamping forces determined by means of the clamping force determining device (36), wherein it is preferably provided that the clamping device (39) has an input device (69) which is connected to the setting device (67) by means of a signal, by means of which the clamping forces determined by means of the clamping force determining device (36) are entered, in particular manually. [7] Method according to one of the preceding claims, characterized by that the clamping element (47; 75) of the clamping device (39; 73) is fixed in place and that by means of the pressing device (61; 95) of the clamping device (39; 73) at least one of the clamping elements (47, 55; 75, 81) is pressed and / or pushed against the upper end wall (11) and / or against the at least one supporting wall region (13) of the cylinder liner (9). [8] Method according to one of the preceding claims, characterized bythat the at least one marking (99, 101) is arrow-shaped and / or triangular. [9] Device for machining a cylinder liner (9) as a separate component of an internal combustion engine, in particular for carrying out a method according to one of the preceding claims, with a clamping device (39; 73), by means of which the cylinder liner (9) can be clamped, such that the clamping device (39; 73) at least approximately corresponds to a clamping state of the cylinder liner (9) in which it is clamped. Sp ) on the cylinder liner (9), with a machining device (41) by means of which the running surface (29) of the cylinder liner (9) clamped by means of the clamping device (39; 73) can be machined, such that at least one bulge (31, 35) of the running surface (29) projecting inwards into a piston receiving space (30) of the cylinder liner (9) clamped by means of the clamping device (39; 73) can be removed by means of the machining device (41), wherein the clamping device (39; 73) has a first clamping element (55; 81) which, in the clamped state of the cylinder liner (9), is in planar contact with an upper end wall (11) of the cylinder liner (9), and wherein the clamping device (39; 73) has a second clamping element (47; 75) which, in the clamped state of the cylinder liner (9), is in planar contact with at least one supporting wall region (13) of the cylinder liner (9) facing away from the end wall (11), wherein at least one clamping element (75) and the cylinder liner (9) each have an externally visible marking (99, 101) as an indication for an arrangement of the cylinder liner (9) in a defined rotational position relative to the clamping element (47; 75), and wherein the clamping device (39; 73) has a pressing device (61; 95) by means of which at least one of the clamping elements (47, 55; 75, 81) can be pressed and / or pushed against the cylinder liner (9) for clamping the cylinder liner (9), and wherein the cylinder liner (9) is formed by a downstop bush, and wherein the second clamping element (47; 75) has a receiving space (49; 83) in which the cylinder liner (9) can be arranged at least in sections, wherein at least one wall region (53; 85) of the second clamping element (47; 75) delimiting the receiving space (49; 83) forms a guide for the cylinder liner (9) arranged in the receiving space (49; 83) transversely to the vertical axis direction (z), in such a way that a displacement of the cylinder liner (9) arranged in the receiving space (49; 83) relative to the second clamping element (47; 75) in the transverse axis direction (y) and in the longitudinal axis direction (x) and a rotation of the cylinder liner (9) arranged in the receiving space (49; 83) relative to the second clamping element (47; 75) about a transverse axis running in the transverse axis direction (y) and about a longitudinal axis running in the longitudinal axis direction (x) is prevented. [10] Device according to claim 9, characterized bythat the support wall region (13) of the cylinder liner (9), viewed in the liner axial direction (x), is arranged in a lower and / or in a middle region (23) of the cylinder liner (9). [11] Device according to claim 9 or 10, characterized by that the first clamping element (55; 81) has a continuous, in particular cylindrical, recess (59; 93) through which a machining tool (43) of the machining device (41) can be passed, in particular with a defined gap distance, wherein it is preferably provided that the first clamping element (55; 81) is substantially annular and / or tubular. [12] Device according to one of claims 9 to 11, characterized by that by means of the pressing device (61; 95) at least one of the clamping elements (47, 55; 75, 81) can be pressed and / or pushed against the upper end wall (11) and / or against the at least one supporting wall region (13) of the cylinder liner (9). [13] Device according to claim 12, characterized by that the second clamping element (47; 75) is fixed in place, and that the pressing device (61) has an actuating element (63), in particular an actuating arm, which is connected or connectable to the first clamping element (55; 75) and by means of which the first clamping element (55) can be pressed against the cylinder liner (9), wherein it is preferably provided that the actuating element (63) can be actuated by means of a drive device (65). [14] Device according to claim 12, characterized bythat the pressing device is formed by a plurality of screw connections (95) by means of which the clamping elements (75; 81) can be connected to one another, wherein the clamping elements (75; 81) can be pressed against the cylinder liner (9) by means of the screws (97) of the screw connections (95), wherein it is preferably provided that in the clamping state of the clamping device (73) the clamping elements (75; 81) connected by means of the screw connections (95) are in, in particular flat, contact with one another.

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