JP4193086B2 - Cylinder bore machining method and machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cylinder bore machining method and a machining apparatus used for forming a cylinder bore in a cylinder block, for example, in the manufacture of an automobile engine.
[0002]
[Prior art]
As this type of processing method and processing apparatus, for example, there are those described in JP-A-6-126543 and JP-A-8-252764.
[0003]
The technique disclosed in Japanese Patent Laid-Open No. 6-126543 is processing of a cylinder block, and after roughing the cylinder head joint surface in the cylinder block, roughing, finishing and honing of the inner surface of the cylinder bore in the cylinder block Then, finally, the cylinder head joint surface is finished to remove the distortion of the cylinder head joint surface that occurs when the inner surface of the cylinder bore is machined.
[0004]
In addition, the technique disclosed in Japanese Patent Application Laid-Open No. 8-252644 is a honing method by holding the cylinder bore side wall portion of the cylinder block from both sides with a backup tool when the cylinder bore is finished by honing. The cylinder bore side wall that has received the pressing pressure of the grindstone is prevented from being deformed outward, thereby improving the roundness of the cylinder bore.
[0005]
[Problems to be solved by the invention]
However, in the conventional machining of the cylinder bore as described above, the cylinder bore can be formed with high accuracy in the cylinder block alone, but the distortion of the cylinder bore that occurs during the subsequent engine assembly cannot be avoided. In other words, even if the cylinder bore is accurately formed so as to be almost a perfect circle in the past, when the cylinder head is fixed to the cylinder block with a bolt during engine assembly, the cylinder block is stress-biased by tightening the bolt. This causes a problem that the cylinder bore is deformed, and it has been a problem to solve such a problem.
[0006]
If the cylinder bore is deformed, the airtightness of the cylinder is impaired and sufficient engine performance cannot be obtained. Such a cylinder bore deformation phenomenon is described in the paper by Klaus Loenne, Ron Ziemba, “The GOETZE Cylinder Distortion System and the Possibilities of Redevelopment Cylinders, Eighteenth.
[0007]
OBJECT OF THE INVENTION
The present invention has been made paying attention to the above-mentioned conventional problems. When forming the cylinder bore in the cylinder block, the cylinder bore can be made into a substantially perfect circular cylinder shape in a state where the cylinder head is fixed later. An object of the present invention is to provide a processing method and a processing apparatus.
[0008]
[Means for Solving the Problems]
According to the cylinder bore machining method of the present invention, as claimed in claim 1, when the cylinder bore is formed on the cylinder block, the cylinder bore is primarily formed on the cylinder block. The cylinder bore is secondarily molded into a non-circular shape with the cylinder head removed, and after the second molding When the cylinder head is fixed to the cylinder block The non-circular cylinder bore is deformed to approach the perfect circle. According to claim 2, after the cylinder bore is primarily formed in the cylinder block, the cylinder head is fixed to the cylinder block, the roundness of the cylinder bore is measured, the cylinder head is removed, and the measured roundness error A cylinder bore in which a cylinder bore is secondarily molded in a non-circular shape having an inverted phase with respect to a curve, and a cylinder head fixing bolt is attached to the outer peripheral side of the cylinder bore, wherein the cylinder bore is formed by secondary molding. This non-circular shape maximizes the radius in the direction of the bolt and minimizes the radius in the middle direction, and at least the difference between the maximum radius and the minimum radius to the roundness of the cylinder bore when the cylinder head is fixed. And a non-circular shape having a size based on the cylinder head. Roundness of the cylinder bore in the Yes in advance data of, and a configuration of forming the secondary cylinder bores to-true circular shape on the basis of the data, and a means for solving the conventional problems with the configuration described above.
[0009]
According to a fifth aspect of the present invention, there is provided a cylinder bore machining apparatus according to claim 5, wherein the cylinder bore is formed into a non-circular shape corresponding to the amount of deformation of the cylinder bore when the cylinder head is fixed to the cylinder block. A honing tool which is provided with a grindstone on the outer peripheral part and is driven to rotate by being inserted into a cylinder bore, tool rotation angle detecting means for detecting the rotation angle of the honing tool, and a grindstone in the honing tool Fine movement means for changing the pressing force of the grindstone against the inner surface of the cylinder bore by slightly moving the tool in the radial direction of the tool, and grinding wheel fine movement means based on grinding data for secondary forming of the cylinder bore and rotation angle data from the tool rotation angle detection means And a honing control means for controlling the hoist. And a grinding tool is provided with a grindstone rotatably on a main body portion serving as a tool center via a rotation axis orthogonal to the tool axis, and a grindstone fine movement means between the main body portion and the grindstone. 7, the honing tool has a configuration in which the grindstone fine movement means is provided at two locations in the tool axis direction with the rotation axis in between, and the above configuration is used as a means for solving the conventional problems.
[0010]
In each configuration of the cylinder bore machining method and machining apparatus according to the present invention, the primary forming of the cylinder bore performed on the cylinder block can include roughing or finishing by boring or honing. The secondary molding is mainly performed by honing.
[0011]
Further, in each of the above configurations, the roundness of the cylinder bore is actually measured at a plurality of axial positions as the measurement of the cylindricity because the cylinder bore has a cylindrical shape having a predetermined length in the axial direction. It is more desirable.
[0012]
[Effects of the Invention]
In the cylinder bore machining method according to claim 1 of the present invention, since the cylinder bore is deformed when the cylinder head is fixed to the cylinder block, the cylinder bore is preliminarily formed so that the cylinder bore has a substantially perfect circular shape by this deformation. Process. That is, in the cylinder bore processing method, the cylinder bore is secondarily formed into a non-circular shape corresponding to the amount of deformation of the cylinder bore when the cylinder head is fixed to the cylinder block, with respect to the cylinder bore primarily formed on the cylinder block. If the cylinder head is fixed to the cylinder block after the secondary molding, the non-circular cylinder bore is deformed so as to approach the perfect circle.
[0013]
In the cylinder bore machining method according to claim 2 of the present invention, first, the cylinder head is fixed to a cylinder block in which the cylinder bore is primarily formed, and the roundness of the cylinder bore is measured. For this reason, the measured roundness includes the amount of deformation of the cylinder bore generated by fixing the cylinder head. Next, in the processing method of the cylinder bore, the cylinder head is removed and secondary forming is performed on the cylinder bore. At this time, the cylinder bore is formed into a non-round shape that becomes an inverted phase with respect to the measured error curve of roundness. Secondary molding. Therefore, if the cylinder head is fixed again to the cylinder block after the secondary molding, the non-circular cylinder bore is deformed so as to correct the roundness error of the reverse phase, that is, deformed so as to approach the perfect circle. Become.
[0014]
In the cylinder bore machining method according to the third aspect of the present invention, the cylinder bore is attached with a bolt for fixing the cylinder head on the outer peripheral side. In this case, when the cylinder head is fixed to the cylinder block, the cylinder bore is deformed in a direction in which the radius is reduced at a portion corresponding to the bolt, and is deformed in a direction in which the radius is increased at an intermediate portion thereof. Therefore, in the cylinder bore machining method, when the cylinder bore is secondarily formed into a non-circular shape, the radius in the bolt direction is maximized and the radius in the intermediate direction is minimized, and the difference between the maximum radius and the minimum radius is determined. The size is at least based on the roundness of the cylinder bore when the cylinder head is fixed. As a result, when the cylinder head is fixed to the cylinder block after the secondary molding, the radius of the portion where the bolt is located becomes small and the radius of the intermediate portion of the cylinder bore is within a range based on the roundness. Is deformed so as to become larger, and deformed so as to approach a perfect circle as a whole.
[0015]
In the cylinder bore machining method according to claim 4 of the present invention, the roundness of the cylinder bore in a state where the cylinder head is fixed to the cylinder block is preliminarily converted into data, so that the roundness is measured every time the cylinder bore is primary molded. There is no need to perform the process, and the cylinder bore may be secondarily formed into a non-circular shape based on the data, so that the processing time until the second forming is completed is shortened.
[0016]
In the cylinder bore machining apparatus according to claim 5 of the present invention, the honing tool is inserted into the primary formed cylinder bore and rotationally driven, and honing (secondary forming) is performed on the inner surface of the cylinder bore with the grindstone of the honing tool. At this time, in the cylinder bore machining apparatus, the rotation angle of the honing tool is detected by the tool rotation angle detection means, and the honing control means detects the fine movement of the grindstone based on the rotation angle data of the honing tool and the grinding data of the secondary forming of the cylinder bore. Control means. The cylinder bore grinding data is based on the amount of deformation when the cylinder head is fixed to the cylinder block. That is, while the honing tool rotates once, the grindstone is slightly moved in the tool radial direction according to the grinding data corresponding to the rotation angle, and the pressing pressure of the grindstone against the inner surface of the cylinder bore is partially changed. As the pressing pressure increases / decreases, the grinding amount also increases / decreases. As a result, the cylinder bore is secondarily formed into a non-circular shape corresponding to the amount of deformation when the cylinder head is fixed to the cylinder block.
[0017]
In the cylinder bore machining apparatus according to claim 6 of the present invention, when the grindstone fine movement means in the honing tool is operated, the grindstone rotates about the rotation axis orthogonal to the tool axis. Therefore, if the positional relationship between the cylinder bore and the honing tool is made constant, the inner surface of the cylinder bore is formed into a tapered shape. Further, if the cylinder bore and the honing tool are relatively movable, and the movement and the rotation of the grindstone are combined, the inner surface of the cylinder bore is formed into a medium-drawer shape or a middle-bulge shape.
[0018]
In the cylinder bore machining apparatus according to claim 7 of the present invention, when the two grindstone fine movement means in the honing tool are operated in opposite relations to each other, the grindstone rotates about the rotation axis. Therefore, if the positional relationship between the cylinder bore and the honing tool is made constant, the inner surface of the cylinder bore is formed into a taper shape or a medium drawing shape. Further, if the cylinder bore and the honing tool are relatively movable, and the movement and the rotation of the grindstone are combined, the inner surface of the cylinder bore is formed in a bulging shape.
[0019]
【The invention's effect】
According to the cylinder bore machining method according to claim 1 of the present invention. ,rear In a state where the cylinder head is fixed to the cylinder bore, the cylinder bore can be formed into a substantially perfect circular cylindrical shape. As a result, in the cylinder bore, it is possible to avoid the occurrence of problems such as deterioration of the airtightness of the cylinder and uneven wear of the cylinder liner and the piston, and it is possible to obtain a cylinder block having a cylinder bore that can exhibit sufficient engine performance.
[0020]
According to the machining method of the cylinder bore according to claim 2 of the present invention, the same effect as in claim 1 can be obtained, and the roundness of the cylinder bore formed by primary measurement is measured, and the measured roundness of the cylinder bore is measured. Since the cylinder bores are secondarily formed in a non-circular shape that is an inverted phase with respect to the error curve, each cylinder bore can be secondarily formed with higher accuracy, and in a state where the cylinder head is fixed, Individual cylinder bores can be made into a perfect circle or very close to a perfect circle, and the quality of the cylinder bore and cylinder block can be further enhanced.
[0021]
According to the cylinder bore machining method according to claim 3 of the present invention, in particular, in the cylinder bore in which a bolt for fixing the cylinder head is attached to the outer peripheral side, the cylinder bore is fixed in the state in which the cylinder head is fixed later, as in claim 1. It is possible to obtain a correct circular cylindrical shape.
[0022]
According to the cylinder bore machining method according to claim 4 of the present invention, the same effects as those of claims 1 and 3 can be obtained, and the cylinder bore is secondarily formed based on the roundness converted into data beforehand. Therefore, it is not necessary to measure the roundness of each cylinder bore, simplifying the work and shortening the machining time, especially when mass-producing cylinder blocks with the same configuration. It is possible to efficiently produce a high-quality cylinder block having a cylinder bore.
[0023]
According to the cylinder bore machining apparatus according to claim 5 of the present invention, the honing tool provided with the grindstone, the tool rotation angle detecting means, the grindstone fine movement means, and the honing control means are employed, so that the cylinder bore formed primarily is obtained. In secondary molding, secondary molding can be performed in a non-circular shape corresponding to the amount of deformation when the cylinder head is fixed to the cylinder block. Therefore, if the cylinder head is fixed to the cylinder block after the secondary molding, the cylinder bore can be made into a substantially perfect circular cylinder shape, and a high-quality cylinder equipped with a high-precision cylinder bore that can exhibit sufficient engine performance. You can get a block.
[0024]
According to the cylinder bore machining apparatus according to claim 6 of the present invention, the same effect as in claim 5 can be obtained, and the grindstone is rotated by the rotation shaft and the grindstone fine movement means. When the positional relationship between the cylinder bore and the honing tool is constant, the inner surface of the cylinder bore can be formed into a tapered shape, and when the cylinder bore and the honing tool are relatively movable, the grindstone can be rotated. In combination, the inner surface of the cylinder bore can be formed into a medium drawing shape or a middle expansion shape, and the processing range of the cylinder bore that is secondarily formed into a non-circular shape can be expanded.
[0025]
According to the cylinder bore machining apparatus of the seventh aspect of the present invention, the same effect as in the sixth aspect can be obtained, and when the positional relationship between the cylinder bore and the honing tool is made constant, the inner surface of the cylinder bore can be obtained. If the cylinder bore and honing tool are made relatively movable, the inner surface of the cylinder bore can be made into a bulging shape by combining with the rotation of the grindstone. In particular, since the grindstone is rotated by the rotation shaft at the intermediate portion thereof, the inner surface of the cylinder bore is limited in a case where the axial length of the cylinder bore is relatively short or in a narrow range in the axial direction. It can be formed into a medium drawing shape or a middle swelling shape.
[0026]
【Example】
FIGS. 1-6 is a figure explaining one Example of the processing method and processing apparatus of a cylinder bore concerning this invention.
[0027]
First, the cylinder bore machining method in this embodiment will be described schematically. As shown in B1 to B6 of FIG. 1, the cylinder bore is primarily formed (F1) by boring and honing on the cylinder block. That is, the primary forming includes roughing and finishing of the cylinder bore. The cylinder block is also formed with a cooling fluid flow path.
[0028]
Next, as in the case of engine assembly, the cylinder head is fixed to the cylinder block, and the roundness (cylindricity) of the cylinder bore is measured in this state. At this time, the cylinder bore is deformed by the stress generated by fixing the cylinder head. Therefore, the roundness of the measured cylinder bore includes deformation due to the fixing of the cylinder head.
[0029]
Then, after removing the cylinder head, the cylinder bore is finished to be non-circularly shaped (F2) in accordance with the deformation amount of the cylinder bore obtained by the previous roundness measurement, thereby completing the processing of the cylinder bore. Thereby, if the cylinder head is fixed to the cylinder block after the secondary molding, the non-circular cylinder bore is deformed so as to approach the perfect circle.
[0030]
The above processing steps will be described in detail. The roundness (cylindricity) is measured in the state shown in FIG. The illustrated cylinder block A is provided with four cylinder bores B in series. After the primary molding of the cylinder bore B is completed, a cylinder head C is attached and a predetermined number of bolts are tightened with a predetermined torque. The cylinder head C is completely fixed. Then, the cylinder head C is placed on the measurement base 1 in a posture in which the cylinder head C is on the lower side, and the roundness of the cylinder bore B is measured by a conventionally known roundness measuring device 3 provided with the measuring element 2. At this time, the roundness measurement is performed at, for example, three locations of the upper end M1, the middle M2, and the lower end M3 of the cylinder bore B.
[0031]
As shown in FIG. 3A, roundness error curves E1 to E3 with respect to the reference circles D1 to D3 are obtained for the three measurement parts M1 to M3 by measuring the roundness. As shown in FIG. 3B, the relationship between these reference circles D1 to D3 and the roundness error curves E1 to E3 is the relationship between the angle (position) in the circumferential direction of the cylinder bore B and the error amount (E1). ~ E3). Therefore, in the cylinder bore machining method, the relationship between the inversion phase of the roundness error curves E1 to E3, that is, the angle in the circumferential direction of the cylinder bore B and the error amount (E1) as indicated by the dotted line in FIG. To E3), the inversion phases Ea to Ec are obtained, and the cylinder bore B is secondarily formed into a non-circular shape having the inversion phases Ea to Ec. At this time, the cylinder head C is removed.
[0032]
For secondary molding of the cylinder bore B, a processing device shown in FIGS. 5 and 6 is used.
[0033]
The processing apparatus shown in FIG. 5 includes a horizontally movable table 12 on which a cylinder block A is placed on a base 11, and a spindle head 14 that can be moved up and down with a servo motor 13 as a drive source. The output shaft 15 is provided with a honing tool 16 and tool rotation angle detection means 17 for detecting the rotation angle of the honing tool 16 by detecting the rotation angle of the output shaft 15.
[0034]
The honing tool 16 includes two or three grindstones in a part of the outer peripheral portion, whereas a general honing tool includes approximately ten grindstones in the outer peripheral portion at equal intervals. As shown in FIG. 6, the honing tool 16 has a grindstone 20 attached to the outer peripheral portion of the main body 18 that is the center of the tool together with the holder 19, and contacts the inner surface of the cylinder bore B on the opposite side of the grindstone 20. The upper and lower rollers 21 and 21 rotate in this manner. The roller 21 receives the reaction force when the grindstone 20 is pressed against the inner surface of the cylinder bore B.
[0035]
In addition, the honing tool 16 includes a grindstone fine movement means 22 that changes the pressing pressure of the grindstone 20 against the inner surface of the cylinder bore B by slightly moving the grindstone 20 in the tool radial direction between the main body 18 and the holder 19 of the grindstone 20. I have. As the grindstone fine moving means 22, for example, a piezoelectric element that expands and contracts by a change in load voltage is used.
[0036]
The above machining apparatus is driven and controlled by the honing control means 23. The honing control means 23 generates a voltage for applying a voltage to the arithmetic device 24 for creating a program, the NC device 25 as a main control unit, the controller 26 for the servo motor 13 and the tool rotation angle detection means 17, and the grindstone fine movement means 22. A device 27 and a voltage control device 28 for controlling the voltage generated by the voltage generator 27 according to a command from the NC device 25 are provided.
[0037]
In the processing device 24 of the honing control means 23, the above processing device is subjected to an experiment in advance with the inversion phases Ea to Ec of the relationship (E1 to E3) between the angle of the cylinder bore B and the error amount obtained in the previous roundness measurement. Based on the relationship between the grinding wheel pressing pressure and the grinding amount obtained as shown in FIG. 3, a program that associates the rotational angle and axial position of the honing tool 16 with respect to the cylinder bore B and the pressing pressure of the grinding wheel 20, that is, the cylinder bore A program for instructing which position of B and how much grinding is created. This program becomes the grinding data for secondary forming of the cylinder bore B.
[0038]
Then, the machining device inserts the honing tool 16 into the cylinder bore B of the cylinder block A positioned on the table 12 under the control of the NC device 25 and rotationally drives the honing tool 16 to perform honing on the inner surface of the cylinder bore B. At this time, the machining device continues to detect the rotation angle of the honing tool 16 by the tool rotation angle detection unit 17, and the honing control unit 23 detects the rotation angle data from the tool rotation angle detection unit 17 and the arithmetic unit 24. The grinding wheel fine movement means 22 is controlled via the voltage control device 28 and the voltage generation device 27 based on the grinding data of the secondary molding from the above.
[0039]
That is, while the honing tool 16 makes one rotation, the grindstone 20 is slightly moved in the tool radial direction according to the grinding data corresponding to the rotation angle, and the pressing pressure of the grindstone 20 against the inner surface of the cylinder bore B is partially changed. . As a result, the cylinder bore B is secondarily formed into a non-circular shape corresponding to the deformation amount when the cylinder head C is fixed to the cylinder block A.
[0040]
The cylinder bore B that is secondarily molded as described above is deformed by fixing the cylinder head C to the cylinder block A in later engine assembly. Since it is formed into a corresponding non-circular shape, more precisely, a non-circular shape corresponding to the inversion phases Ea to Ec of the error curves E1 to E3 of the measured roundness, it is inverted when the cylinder head C is fixed. The roundness error of the phases Ea to Ec is corrected to be deformed so as to approach the perfect circle.
[0041]
Accordingly, in the cylinder block A, the occurrence of problems such as a decrease in airtightness of the cylinder and uneven wear of the cylinder liner and the piston can be avoided in the cylinder bore B, and sufficient engine performance can be exhibited.
[0042]
In the processing apparatus of the above embodiment, in order to improve the processing accuracy and the like, in addition to detecting the rotation angle of the honing tool 16, the rotation speed of the servo motor 13 and the like are also detected. It is also possible to perform control by feeding back to the NC device 25.
[0043]
Moreover, in the said Example, as shown to B1-B6 of FIG. 1, after forming the cylinder bore B primarily in the cylinder block A, the process order of measuring the roundness of the cylinder bore B was explained, but for example, When repeatedly producing the cylinder block A of a given type or when producing a large number of cylinder blocks A having the same configuration, the roundness of the cylinder bore A with the cylinder head C fixed is previously converted into data. Thus, grinding data is prepared, and the cylinder bore B can be secondarily formed into a non-circular shape based on the data. Thereby, the steps B3 to B5 in FIG. 1 are omitted, the work is greatly simplified, the processing time is shortened, and the high-quality cylinder block A can be efficiently produced.
[0044]
FIG. 7 is a view for explaining a honing tool in another embodiment of the cylinder bore machining apparatus according to the present invention.
[0045]
The illustrated honing tool 36 includes a grindstone 20 together with a holder 39 on an outer peripheral portion of a main body 38, and upper and lower rollers 21 and 21 on the opposite side of the grindstone 20. The grindstone 20 and the holder 39 of the honing tool 36 are rotatable with respect to the main body 38 via a rotation shaft 40 orthogonal to the tool axis at an approximately middle portion in the tool axis direction which is the vertical direction in the figure. It is provided. The upper and lower grinding wheel fine movement means 22 and 22 are provided between the main body 38 and the holder 39 at the upper and lower symmetrical positions with the rotation shaft 40 in between.
[0046]
The honing tool 36 is controlled by the honing control means in the processing apparatus described in the previous embodiment, and the primary formed cylinder bore is secondarily formed into a non-circular shape, and the rotary shaft 40 and the upper and lower grindstones are finely moved. The processing range can be expanded by means 22 and 22.
[0047]
For example, when the upper grindstone fine movement means 22 is extended and the lower grindstone fine movement means 22 is contracted, the cylinder bore is tapered with the lower end portion having a small diameter due to the inclination of the grindstone 20 around the rotation shaft 40. It is formed into a tapered shape. In addition, the cylinder bore B and the honing tool 36 can be moved relative to each other in the axial direction, and can also be moved in a direction perpendicular to the axial line. Can be formed into a taper shape, a middle swelling shape or a middle drawing shape.
[0048]
Note that the cylinder bore machining apparatus according to the present invention can also have a configuration in which a rotating shaft is provided at the upper end or lower end of the grindstone, which makes it possible to form the cylinder bore into a tapered shape or the like. If the rotation shaft 40 is provided in the intermediate portion of the grindstone 20 as in the above embodiment, the inner surface of the cylinder bore is reduced in a relatively short range or a narrow range in the axial direction. It can be formed into a medium drawn shape or a middle swollen shape.
[0049]
FIGS. 8-10 is a figure explaining the other Example of the processing method of the cylinder bore concerning this invention.
[0050]
The cylinder block A shown in FIG. 8 has cylinder head fixing bolts attached to the outer peripheral side of the cylinder bore B, and four bolt mounting holes H are formed at intervals of 90 degrees in the circumferential direction. .
[0051]
In this case, it is confirmed that when the cylinder head is fixed to the cylinder block A, the cylinder bore B is deformed so that the radius in the direction in which the bolt is present decreases and the radius in the intermediate direction of the bolt increases.
[0052]
Therefore, in the processing method of this embodiment, the cylinder bore B has a shape in which the radius in the bolt direction is maximized and the radius in the intermediate direction is minimized, and at least the difference between the maximum radius and the minimum radius is fixed to the cylinder head. Secondary molding is performed so as to obtain a non-round shape having a size based on the roundness of the cylinder bore B in the state.
[0053]
That is, in the arithmetic device 24 of the honing control means 23 shown in FIG. 5, as shown in B11 to B15 of FIG. 9, the number n of bolts (n = 4) is inputted, and the bolt angle θn is inputted. At this time, since four bolts are arranged at intervals of 90 degrees, θ1 = 45 degrees, θ2 = 135 degrees, θ3 = 225 degrees, and θ4 = 315 degrees in the clockwise direction in FIG.
[0054]
Next, the average value Φave of roundness obtained by measuring a large number of cylinder bores in advance is input, and the shape of the cylinder bore is calculated from the angles θ1 to θ4 of each bolt and the average value Φave of roundness. At this time, as shown in FIG. 10A, the shape data can be expressed as a sine wave having one cycle between the bolts and having an amplitude corresponding to the average value Φave. Then, this shape data is transferred to the NC device 25, and the cylinder bore B is secondarily formed into a non-circular shape.
[0055]
As a result, the cylinder bore B has a maximum radius Rmax in the direction of each bolt, that is, in the direction of each bolt mounting hole H, as shown in FIG. The difference between the radius Rmax and the minimum radius Rmin is formed into a non-circular shape having a size corresponding to the roundness average value Φave.
[0056]
Therefore, when the cylinder head is fixed to the cylinder block A, the cylinder bore B is deformed so that the radius decreases in the direction of the bolt mounting hole H and increases in the intermediate direction, and the non-circular shape as a whole. The cylinder bore B is deformed so as to approach a perfect circle.
[0057]
In addition, since the deformation of the cylinder bore accompanying the fixing of the cylinder head is mainly caused by bolt tightening, as described above, according to the processing method using the bolt position and the roundness average value, The shape of the cylinder bore to be formed next can be easily determined, and no work such as correction is required, and a high-quality cylinder block having a high-precision cylinder bore can be obtained.
[Brief description of the drawings]
FIG. 1 is a block diagram for explaining an example of a process in an embodiment of a cylinder bore machining method according to the present invention.
FIG. 2 is a side view illustrating roundness measurement of a cylinder bore.
FIG. 3 is an explanatory diagram (a) showing a roundness error curve obtained by measuring roundness, a graph (b) showing a relationship between a cylinder bore angle and an error amount, and an inverted phase of the relationship between the angle and the error amount. It is a graph (c) shown.
FIG. 4 is a graph showing the relationship between the pressing pressure of the grindstone and the grinding amount.
FIG. 5 is an explanatory view showing an embodiment of a cylinder bore machining apparatus according to the present invention.
FIG. 6 is a cross-sectional view illustrating a honing tool.
FIG. 7 is a cross-sectional view illustrating a honing tool in another embodiment of the cylinder bore machining apparatus according to the present invention.
FIG. 8 is a plan view illustrating a cylinder block in another embodiment of the cylinder bore machining method according to the present invention.
FIG. 9 is a block diagram showing a process of creating shape data in another embodiment of the cylinder bore machining method according to the present invention.
FIG. 10 is a graph (a) for explaining shape data and an explanatory diagram (b) showing the shape of a cylinder bore to be secondarily formed.
[Explanation of symbols]
A Cylinder block
B Cylinder bore
C Cylinder head
16 36 Honing tool
17 Tool rotation angle detection means
18 38 Honing tool body
20 Whetstone
22 Grinding wheel fine movement means
23 Honing control means
40 Rotating shaft

Claims (7)

When forming the cylinder bore in the cylinder block, after the cylinder bore is primary molded to the cylinder block, the cylinder bore is secondarily molded into a non-circular shape with the cylinder head removed, and the cylinder head is fixed to the cylinder block after the secondary molding. cylinder bore processing methods, wherein to Rukoto as not-true circular bore approaches the true circle is deformed upon.   After first forming the cylinder bore on the cylinder block, fix the cylinder head to the cylinder block, measure the roundness of the cylinder bore, remove the cylinder head, and the phase will be reversed with respect to the error curve of the measured roundness The cylinder bore machining method according to claim 1, wherein the cylinder bore is secondarily formed into a non-circular shape.   A cylinder bore to which a cylinder head fixing bolt is attached on the outer peripheral side, and the non-circular shape of the cylinder bore by secondary molding maximizes the radius in the direction of the bolt and minimizes the radius in the middle direction 2. The cylinder bore machining method according to claim 1, wherein the cylinder bore has a non-circular shape in which a difference between the maximum radius and the minimum radius is at least a size based on the roundness of the cylinder bore when the cylinder head is fixed.   4. The roundness of the cylinder bore in a state where the cylinder head is fixed to the cylinder block is previously converted into data, and the cylinder bore is secondarily formed into a non-round shape based on the data. The cylinder bore machining method described.   A processing device that secondary-forms the cylinder bore into a non-circular shape corresponding to the amount of deformation of the cylinder bore when the cylinder head is fixed to the cylinder block with respect to the cylinder bore primary-formed on the cylinder block. A honing tool which is inserted into the cylinder bore and is driven to rotate, tool rotation angle detecting means for detecting the rotation angle of the honing tool, and the grindstone in the honing tool is slightly moved in the tool radial direction to move the grindstone against the inner surface of the cylinder bore. A cylinder bore comprising: a grinding wheel fine movement means for changing the pressing pressure; and a honing control means for controlling the grinding wheel fine movement means on the basis of grinding data for secondary forming of the cylinder bore and rotation angle data from the tool rotation angle detection means. Processing equipment.   The honing tool is characterized in that a grindstone is rotatably provided on a main body portion serving as a tool center via a rotation axis orthogonal to the tool axis, and a grindstone fine movement means is provided between the main body portion and the grindstone. The cylinder bore machining apparatus according to claim 5.   7. The cylinder bore machining apparatus according to claim 6, wherein the honing tool is provided with a grindstone fine movement means at two locations in the tool axis direction with the rotation axis in between.

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