JP4533866B2 - Composite machine tool and cylinder block bore boring method using the composite machine tool - Google Patents

Description

  The present invention relates to a complex machine tool capable of performing a plurality of different machining operations and a boring method for a bore of a cylinder block using the complex machine tool.

  According to a machine tool used for conventional boring and honing, for example, machining can be performed to a state close to a perfect circle with respect to a bore of a cylinder block that is a workpiece.

  However, for example, even if the bore of a cylinder block of an automobile engine is processed as a single item into a perfect circle, the bore is deformed by assembling a cylinder head, a crankcase, or the like in the subsequent production process. If the bore is deformed in this way, it causes a sliding resistance between the bore and the piston when the engine is used, and there is a concern that the engine cannot exhibit a desired output.

  Therefore, in Patent Document 1, a dummy head having a hole larger in diameter than the bore of the cylinder block and having a rigidity similar to that of the cylinder head is attached to the cylinder block, and the cylinder block is tightened with the cylinder head. After performing the same conditions as described above, it is described that the bore processing is performed from the large-diameter hole. For the dummy head as described above, for example, as shown in Patent Document 2, various proposals have been made for processing the bore with higher accuracy.

  Patent Document 3 describes that, instead of the dummy head, bore processing is performed in a state where the cylinder peripheral portion of the cylinder block is pressed by a pressing device.

  However, in the above-described conventional technique, it is necessary to attach and detach a dummy head or the like at the time of bore machining of each cylinder block during production. For this reason, productivity will fall significantly. Furthermore, the so-called dummy parts as described above have a problem that it is difficult to reproduce a complete assembled state in a product.

  Accordingly, there is a demand for a machining method that can reproduce the state closer to the assembled state of the product and the productivity of the cylinder block. However, in order to realize such a machining method, a machine tool capable of performing bore machining with higher accuracy is required.

  In such a machine tool, the present applicant has proposed a composite machine tool capable of performing boring (boring) and honing in a composite manner (Patent Document 4). According to the composite machine tool, it is possible to omit the oscillation mechanism used during the honing process, to save the processing line, simplify the equipment, and reduce the manufacturing cost of the processed product. Further, when boring with a heavy machining load, machining can be performed with a greater axial rigidity, and bore machining can be performed with high accuracy.

  In the machine tool as described above, the expansion force or position control of the boring tool in the bore radial direction is performed by hydraulic pressure or the like. For this reason, it is difficult to control (finely adjust) the expansion force and the expansion position, and there is a limit to performing bore machining with higher accuracy.

Japanese Patent Publication No.51-25523 JP 2000-52228 A Japanese Examined Patent Publication No. 61-57121 Japanese Patent No. 3270683

  The present invention has been made in consideration of the related problems, and an object of the present invention is to provide a complex machine tool capable of performing higher-precision machining at the time of bore machining of a cylinder block, for example. . Further, according to the present invention, by using such a composite machine tool, a cylinder which can reproduce a state closer to the assembled state in the product in the bore machining of the cylinder block and can improve productivity. An object of the present invention is to provide a method for boring a block bore.

  The composite machine tool of the present invention includes a hollow spindle shaft that is rotated by a driving means, a housing that supports the spindle shaft inside, a housing that is housed in the spindle shaft, and is capable of moving forward and backward in the axial direction. A shaft that is spline-fitted with the shaft, and a processing head that is connected to the tip of the spindle shaft and is supported so as to be freely expandable and contractable in the centrifugal direction. Expansion means for expanding the boring bit and the honing grindstone at a predetermined position and with a predetermined expansion force by the shaft moving forward and backward is provided, and the boring bit and the honing grindstone are expanded. Thus, the machine tool for performing boring and honing, wherein the expansion means A servo motor fixed to the ring, a pinion gear that is rotated or fixed to a desired phase by the servo motor, and teeth on the outer periphery mesh with the pinion gear, and a thread portion is formed on the inner periphery, and a shaft is formed on the housing. The cylindrical ring gear that is supported and the threaded portion formed on the outer periphery mesh with the threaded portion of the ring gear, so that the cylindrical ball screw that is movable in the axial direction of the shaft, and the shaft It has an inner race fitted to the outer periphery and a bearing constituted by an outer race fitted to the inner periphery of the ball screw, and the shaft is configured to be able to move forward and backward.

  Further, the composite machine tool of the present invention includes a hollow spindle shaft that is rotated by a driving means, a housing that supports the spindle shaft inside, a housing that is housed in the spindle shaft, and is capable of moving forward and backward in the axial direction. A shaft that is spline-fitted with the spindle shaft, and a processing head that is connected to the tip of the spindle shaft and is supported so as to be able to expand and contract in the centrifugal direction, and provided with a honing grindstone. Is provided with an expansion means for expanding the boring bit and the honing grindstone at a predetermined position and with a predetermined expansion force as the shaft moves forward and backward, and expands the boring bit and the honing grindstone. A combined machine tool for boring and honing, wherein the expansion means includes: Comprising a dynamic breaking mechanism having a power converting means for converting the rotational power into linear power, characterized in that it is configured with the shaft to be moved forward and backward.

  According to such a configuration, it is possible to easily and accurately control the expansion force and the expansion position during the expansion operation of the boring tool and the honing grindstone by the expansion means. Therefore, highly accurate boring and honing can be realized.

  The cylinder block bore boring method of the present invention is a cylinder block bore boring method using the above-mentioned composite machine tool, and has an opening into which the machining head can be inserted, simulating a product cylinder head A first step of attaching a dummy head to a cylinder block material before boring and performing boring, measuring an inner diameter for each axial position of the bore, and acquiring first inner diameter data; and the first step After the second step, the dummy head is removed from the cylinder block, the inner diameter for each axial position of the bore is measured, and second inner diameter data is obtained. After the second step, the first By using the inner diameter data of the cylinder block as a correction value for the second inner diameter data, the cylinder block material was bored without mounting the dummy head. When the dummy head is mounted, a third step of creating NC data so that the bore has a desired roundness, and after the third step, the NC data is sent to the multi-function machine tool. Input, boring the cylinder block material according to the NC data, mount the product cylinder head on the cylinder block after the boring, measure the inner diameter for each axial position of the bore, the third inner diameter data After the fourth step and after the fourth step, the NC data is corrected by using the third inner diameter data as a correction value, and the cylinder block material is mounted without mounting the dummy head. And a fifth step of creating corrected NC data so that the bore has a desired roundness when the product cylinder head is mounted after boring. To.

  According to such a method, in the boring of the bore of the cylinder block using the composite machine tool according to the present invention, by using the corrected NC data created in the fifth step, a dummy head or the like can be used during production. A cylinder block having a desired roundness can be manufactured without mounting a cylinder, and productivity is greatly improved.

  According to the present invention, the expansion means for expanding the boring bar and the honing grindstone in the composite machine tool has, for example, a power conversion means having a vibration isolation function including a servo motor, a pinion gear, a ring gear, and the like. Therefore, it is possible to easily and accurately control the expansion force and the expansion position during the expansion operation of the boring tool and the honing grindstone. Further, according to the present invention, it is possible to create corrected NC data in the boring of the cylinder block bore, and to effectively use the corrected NC data during production. For this reason, it becomes possible to manufacture a cylinder block having a desired roundness without mounting a dummy head or the like, and the productivity of the cylinder block is greatly improved.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a bore boring method for a bore of a cylinder block according to the present invention will be described in detail with reference to the accompanying drawings by giving a preferred embodiment in connection with a complex machine tool that performs the machining method.

  FIG. 1 is a partial cross-sectional schematic configuration diagram of a composite machine tool 10 according to an embodiment of the present invention. FIG. 2 is a perspective view of the machining head 12 attached to the composite machine tool 10. FIG. 3 is a perspective view for explaining the internal structure of the machining head 12. The compound machine tool 10 is a machine tool that inserts a machining head 12 into a workpiece 14 (for example, a bore of a cylinder block of an automobile engine) and performs boring or honing.

  The composite machine tool 10 is inserted into the workpiece 14 as described above, and has a machining head 12 having a substantially cylindrical shape that can be enlarged or reduced in diameter, a first gear set 16 and a second gear set 18, A first servo motor 20 and a second servo motor 22 for rotationally driving the first gear set 16 and the second gear set 18, a spindle shaft 24 to which the machining head 12 is connected, and the spindle shaft 24 in the axial direction (arrows) And a moving mechanism 26 for moving forward and backward in the A direction). The first gear set 16 and the second gear set 18 serve to transmit the driving force from the first servo motor 20 and the second servo motor 22 to the machining head 12 as an expansion force. The first gear set 16, the second gear set 18, the first servo motor 20, the second servo motor 22, the spindle shaft 24, and the like are housed in a housing 28.

  The spindle shaft 24 is supported by a housing 28 via a bearing (not shown) and the like, and a gear 23 provided on the outer surface of the spindle shaft 24 is engaged with a gear 25 driven by a driving means such as a motor (not shown). And is driven to rotate. For the rotation of the spindle shaft 24, for example, a belt / pulley mechanism or the like may be used.

  The moving mechanism 26 includes a rail 27 that guides guide portions 28 a and 28 b provided in the housing 28, and a ball screw 29 that is provided side by side with the rail 27 and that is screwed with the screw portion 28 c of the housing 28 by a ball spiral. Accordingly, when the ball screw 29 is rotationally driven by the servo motor 31, the spindle shaft 24 is driven forward and backward in the direction of arrow A.

  Furthermore, the composite machine tool 10 is provided with a control unit 30 that controls the expansion force of the machining head 12, that is, the drive of the first servo motor 20 and the second servo motor 22, the drive of the servo motor 31, and the like. Various NC data and the like for machining the workpiece 14 are recorded in the control unit 30.

  As shown in FIG. 2, the machining head 12 includes a rough honing grindstone that is alternately inserted into a substantially cylindrical main body 32 and holes 34 that are radially formed on the peripheral surface of the main body 32 at equal intervals. 36 and a finishing honing grindstone 38. Further, a boring tool 42 (FB tool, fine boring tool) is inserted into the hole 40 formed in the peripheral surface of the main body 32. Further, for example, four air micro detection means 44 are arranged radially on the peripheral surface of the main body 32 between the rough honing grindstone 36 and the finishing honing grindstone 38. The air micro detection means 44 measures the inner diameter of the workpiece 14 by ejecting air supplied from an air passage (not shown) formed in the machining head 12 from an air nozzle 44a.

  As the roughing honing grindstone 36 and the finishing honing grindstone 38, for example, a metal bond diamond grindstone or a vitrified bond grindstone is used. Usually, the coarse honing grindstone 36 is coarser than the finishing honing grindstone 38, but these may be the same type or the same.

  Further, the machining head 12 is provided with a bite holder 46 to which a not-shown throw-away tip is attached in the vicinity of the outer peripheral tip. The tool holder 46 can be replaced by a bolt 46a. Such a tool holder 46 is connected to an expansion member (not shown) similar to an expansion member (taper cone) to be described later, and can be movable (expanded) in the radial direction.

  As shown in FIG. 3, the machining head 12 has three roughening honing stones 36 and three finishing honing stones 38. The roughing honing grindstone 36 and the finishing honing grindstone 38 are fixed to a roughening grindstone shoe 48 (grinding stone base) and a finishing grindstone shoe 50 (grinding stone base), respectively. A boring bar 42 is provided on the front end side of the finishing grindstone shoe 50. In the boring tool 42, a bolt 52 is screwed into a female screw (not shown) of the main body 32, and is fixed to a pin 56 via a cartridge 54 made of an elastic member such as a leaf spring.

  The rough honing grindstone 36 and the finishing honing grindstone 38 can move (shrink) in the radial direction (the direction of arrow B in FIG. 3) while being guided by the hole 34 at the same position in the axial direction of the processing head 12. Similarly, the boring bar 42 is movable (contracted) in the radial direction while being guided by the hole 40.

  Further, a roughing taper cone 58 for expanding the roughening grindstone shoe 48 in the radial direction is slidably accommodated in the machining head 12. A finishing taper cone 60 for expanding the finishing grindstone shoe 50 in the radial direction is inserted into the roughing taper cone 58 separately from the roughing taper cone 58. As shown in FIGS. 3 and 4, the inner inclined surfaces 48 a and 48 b of the roughing grindstone shoe 48 are slidably in contact with the tapered surfaces of the tapered portions 58 a and 58 b of the roughing taper cone 58. Similarly, as shown in FIGS. 3 and 5, the inner inclined surfaces 50 a and 50 b of the finishing grindstone shoe 50 are slidably in contact with the tapered surfaces of the tapered portions 60 a and 60 b of the finishing taper cone 60. . Further, as shown in FIGS. 3 and 5, a bite taper portion 62 for expanding the pin 56 (boring bite 42) in the radial direction is provided on the tip side of the taper portion 58 a in the finishing taper cone 60. ing.

  As shown in FIG. 4, the tip of the rough taper cone 58 is divided into three forks. Thus, each taper portion 60a, 60b of the finishing taper cone 60 is sandwiched in each gap 64 of the rough taper cone 58 formed by being divided into three forks (see FIG. 3). At this time, the tip end portion of the finishing taper cone 60 including the cutting taper portion 62 protrudes from the tip end portion of the rough taper cone 58.

  6 is a cross-sectional view taken along line VI-VI in FIG. 3, and FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. As shown in FIGS. 6 and 7, in the state where the machining head 12 is connected to the spindle shaft 24, the rough taper cone 58 and the finishing taper cone 60 are connected to shafts 66 and 68, respectively. The shafts 66 and 68 have a cylindrical shape (hollow shape), and the shaft 68 is coaxially inserted into the shaft 66.

  Accordingly, when expanding the boring tool 42, when the shaft 68 is moved forward and the finishing taper cone 60 is pushed in the direction of the arrow A2, the tool taper portion 62 presses the pin 56 (see FIG. 8). For this reason, when the cartridge 54 is elastically deformed (warped) with the bolt 52 fixed to the main body 32 as a fulcrum, the main body 32 is moved in the direction of arrow B (outside in the radial direction). It is expanded while being guided by the hole 40 of the.

  On the other hand, when the roughening honing grindstone 36 is expanded, when the shaft 66 is retracted and the roughening taper cone 58 is pulled in the direction of the arrow A1, the tapered portions 58a and 58b become the inner inclined surfaces 48a and 48b of the roughening grindstone shoe 48. Is pressed (see FIG. 9). Therefore, each rough honing grindstone 36 is radially expanded while being guided by the hole 34 of the main body 32 in the direction of arrow B (outside in the radial direction). When the rough honing grindstone 36 is contracted from the expanded state, the shaft 66 is moved forward and the rough taper cone 58 is pushed in the direction of the arrow A2. Then, each roughing honing stone 36 is contracted in the direction opposite to the arrow B (inward in the radial direction) while being guided by the hole 34.

  Similarly, when the finishing honing grindstone 38 is expanded, when the shaft 68 is retracted and the finishing taper cone 60 is pulled in the direction of the arrow A1, the tapered portions 60a and 60b are inclined to the inner inclined surface 50a of the finishing grindstone shoe 50, 50b is pressed (see FIG. 10). Therefore, each finishing honing grindstone 38 is radially expanded while being guided by the hole 34 of the main body 32 in the direction of arrow B (the centrifugal direction of the diameter). Further, when the finishing honing grindstone 38 is contracted from the expanded state, the shaft 66 is moved forward and the finishing taper cone 60 is pushed in the direction of the arrow A2. Then, each finishing honing grindstone 38 is contracted in the direction opposite to the arrow B (inward in the radial direction) while being guided by the hole 34.

  Therefore, in the machining head 12 in this embodiment, the roughing grindstone shoe 48, the finishing grindstone shoe 50, the roughening taper cone 58, and the finishing taper cone 60 are provided with the boring bar 42, the roughing honing grindstone 36, and the finishing honing grindstone 38. It functions as a member for expansion (contraction) for expanding (contraction).

  As shown in FIG. 1, the machining head 12 configured as described above is connected to the spindle shaft 24. Accordingly, the machining head 12 is also rotated in accordance with the rotation of the spindle shaft 24. The

  On the other hand, as shown in FIGS. 1 and 11, shafts 66 and 68 are accommodated in the spindle shaft 24 having a cylindrical shape (hollow shape) so as to be movable in the direction of arrow A and coaxially. The inner peripheral surface of the spindle shaft 24 and the outer peripheral surface of the shaft 66, and the inner peripheral surface of the shaft 66 and the outer peripheral surface of the shaft 68 are in contact with each other by spline fitting (see FIG. 12). For this reason, the shafts 66 and 68 are movable (slidable) in the direction of arrow A individually or simultaneously within the spindle shaft 24, while rotating substantially integrally with the spindle shaft 24 in the rotational direction.

  The shafts 66 and 68 are respectively connected to the first gear set 16 and the second gear set 18 on the rear end side opposite to the front end side connected to the rough taper cone 58 and the finishing taper cone 60 of the machining head 12. Yes. Therefore, in the composite machine tool 10, when the first gear set 16 is driven by the first servomotor 20, the shaft 66 moves forward and backward. Similarly, when the second gear set 18 is driven by the second servomotor 22, the shaft 68 moves forward and backward.

  Here, with reference to FIG.11 and FIG.13, the structure of the 1st gear set 16 and the 2nd gear set 18 is demonstrated. FIG. 13 is a partially omitted schematic perspective view for explaining a meshing state of each gear in the first gear set 16. The meshing state of each gear in the second gear set 18 is substantially the same as that in the first gear set 16 shown in FIG.

  The first gear set 16 includes a pinion gear 70 connected to the drive shaft 20a of the first servomotor 20 and an outer spur gear 72a meshing with the pinion gear 70, and a ball screw female screw 72b (thread portion) on the inner periphery. Has a cylindrical ring gear 72 and a cylindrical ball screw 74 whose outer peripheral male screw 74 a (threaded portion) meshes with the female screw 72 b of the ring gear 72. Further, the first gear set 16 includes an inner race 76a (inner ring) fitted to the outer periphery of the shaft 68, an outer race 76b (outer ring) fitted to the inner periphery of the ball screw 74, and a rolling element 76c. Bearing 76 is provided. The pinion gear 70 is pivotally supported on the housing 28 by bearings 78 and 80. The ring gear 72 is pivotally supported on the housing 28 by bearings 82 and 84. The inner race 76a may be formed integrally with the outer periphery of the shaft 68, and similarly, the outer race 76b may be formed integrally with the inner periphery of the ball screw 74.

  Similarly, in the second gear set 18, a pinion gear 86 connected to the drive shaft 22 a of the second servomotor 22 and an outer spur gear 88 a mesh with the pinion gear 86, and a ball screw female screw 88 b ( A cylindrical ring gear 88 in which a thread portion is engraved, and a cylindrical ball screw 90 in which an outer peripheral male screw 90 a (thread portion) meshes with a female screw 88 b of the ring gear 88. Further, the second gear set 18 includes an inner race 92a (inner ring) fitted to the outer periphery of the shaft 66, an outer race 92b (outer ring) fitted to the inner periphery of the ball screw 90, and a rolling element 92c. Bearing 92 is provided. The pinion gear 86 is pivotally supported on the housing 28 by bearings 94 and 96. The ring gear 88 is pivotally supported on the housing 28 by bearings 98 and 100. The inner race 92 a may be formed integrally with the outer periphery of the shaft 66, and similarly, the outer race 92 b may be formed integrally with the inner periphery of the ball screw 90.

  Accordingly, in the first gear set 16, when the first servo motor 20 is rotationally driven under the control of the control unit 30, the pinion gear 70 is rotationally driven. Next, when the ring gear 72 is rotationally driven, the ball screw 74 moves forward and backward in the direction of arrow A according to the rotational direction. Here, since the ball screw 74 and the shaft 68 are connected via the bearing 76, the shaft 68 moves forward and backward as the ball screw 74 moves forward and backward.

  At this time, the pinion gear 70 is rotatable by the first servo motor 20 and can be fixed to a desired phase. For this reason, the shaft 68 can also move forward and backward and can be fixed at a desired position (in the direction of arrow A). That is, since the finishing taper cone 60 connected to the shaft 68 is also movable forward and backward and can be fixed at a desired position, the boring bit 42 and the finishing honing grindstone 38 can be expanded (contracted) and desired. It is configured to be freely fixed at the position (arrow B direction).

  Similarly, in the second gear set 18, the pinion gear 86 can be rotated by the second servo motor 22 and fixed to a desired phase under the control of the control unit 30. For this reason, the shaft 66 can also move forward and backward and can be fixed at a desired position (in the direction of arrow A). Accordingly, since the rough taper cone 58 coupled to the shaft 66 is also movable forward and backward and can be fixed at a desired position, the rough honing grindstone 36 can be expanded (contracted) and at a desired position (in the direction of arrow B). ) Can be fixed freely.

  As described above, in the multi-task machine tool 10, the first servo motor 20, the second servo motor 22, the pinion gears 70 and 86, the ring gears 72 and 88, the ball screws 74 and 90, and the bearings 76 and 92 include the boring bar. 42, functions as expansion (contraction) means for expanding (contracting) the rough honing grindstone 36 and the finishing honing grindstone 38.

  In the composite machine tool 10, as shown in FIGS. 1 and 11, the first servo motor 20 and the second servo motor 22 are arranged in opposite directions and in parallel with the shafts 66 and 68 interposed therebetween. Furthermore, by arranging the ring gears 72 and 88, the ball screws 74 and 90 and the bearings 76 and 92 on the same axis, the overall configuration of the composite machine tool 10 is greatly reduced (compact). .

  Next, a method of boring and honing machining of a bore of a cylinder block of an automobile engine as a workpiece by the composite machine tool 10 configured as described above is basically described with reference to the flowchart of FIG. explain.

  First, in step S1 in FIG. 14, the dummy head 104 is attached to the cylinder block 102a, which is a cylinder block material, by the bolt 104a. The dummy head 104 has a shape and a material imitating a product cylinder head, and has a hole 104b having a diameter larger than that of the bore 103 of the cylinder block 102a (see FIG. 15A).

  Next, in step S2, when the cylinder block 102a is disposed at a predetermined position, the machining head 12 (spindle shaft 24) is moved to the bore 103 (in the direction of arrow A1) by the moving mechanism 26 under the control of the control unit 30. It is moved toward.

  In step S <b> 3, the first servo motor 20 is driven under the control of the control unit 30, and the shaft 68 advances in the direction of arrow A <b> 2 by the action of the first gear set 16. At this time, since the finishing taper cone 60 moves forward by the shaft 68, the pin 56 is pressed in the radial direction (arrow B direction) by the cutting taper portion 62. That is, the boring bar 42 is expanded.

  Next, in step S4, the bore 103 of the cylinder block 102a is bored by the boring bar 42. At this time, the servomotor 31 and the first servomotor 20 are appropriately driven and controlled under the control of the control unit 30. That is, the axial position of the machining head 12, the radial position of the boring bar 42, and the expansion force are appropriately controlled. For this reason, the bore 103 is reliably processed to a desired roundness (shape) by the boring bar 42.

  In step S5, under the control of the control unit 30, the cylinder inner diameter (bore diameter) for each axial position (each position in the direction of arrow A) of the cylinder block 102a after the boring is performed is not shown. Measure with a measuring instrument. This measurement data is recorded in the control unit 30, for example, as first inner diameter data (D1). Such measurement of the inner diameter can also be performed using the air micro detection means 44.

  As described above, the first inner diameter data (D1) is measured in order to measure the thermal effect due to processing. This is because, in the boring process, the thermal effect due to the cutting resistance or the like occurs, so that the bore 103 that has become normal temperature after the process is normally contracted. The contraction differs depending on the axial position of the bore 103, and the amount of contraction increases as the thermal effect, that is, the portion with larger thermal expansion.

  Next, in step S6, the dummy head 104 is removed from the cylinder block 102a that has been bored as described above and whose inner diameter has been measured. Then, as shown in FIG. 15B, the inner diameter of the bore 103 of the cylinder block 102a is slightly deformed from the state in step S4 and step S5. That is, the inner diameter shape is deformed by the stress caused by the assembly of other parts, in other words, the assembly of the product cylinder head 106. This time, the stress due to the assembly of the dummy head 104 is regarded as the stress due to the assembly of the product cylinder head 106. Therefore, when the dummy head 104 is removed, the stress disappears, so that the state in steps S4 and S5 is slightly deformed. In addition, since the state in step S4 and step S5 is boring with the compound machine tool 10 provided with the processing head 12 of this embodiment, the said expansion means, etc., it is a substantially perfect circle state.

  Therefore, in step S7, the cylinder inner diameter (bore diameter) for each axial position of the cylinder block 102a after removing the dummy head 104 is measured in the same manner as in step S5. This measurement data is recorded in the control unit 30, for example, as second inner diameter data (D2). The state in step S7 is a state in which the stress is released and deformed from the substantially perfect circle state in steps S4 and S5, and is not a slightly deformed perfect circle.

  In step S8, the first inner diameter data (D2) acquired in step S5 is used as a correction value for the second inner diameter data (D2) acquired in step S7. ) And NC data (DN) is created. The NC data (DN) created in this way has a desired cylinder inner diameter (bore diameter) when the dummy head 104 is mounted after boring the cylinder block material without mounting the dummy head 104. It is data created to have roundness.

  Next, in step S9, the NC data (DN) created in step S8 is input to the control unit 30 of the composite machine tool 10.

  In step S10, first, a cylinder block 102b which is a new cylinder block material different from the cylinder block 102a subjected to the boring process in step S4 is arranged at a predetermined position. Next, under the control of the control unit 30, the cylinder block 102b is subjected to boring processing in accordance with the NC data (DN) input as described above.

  In step S11, the product cylinder head 106 is mounted with the bolt 106a on the cylinder block 102b that has been subjected to the boring process as described above (see FIG. 15C). The product cylinder head 106 is a cylinder head used as an actual product, unlike the dummy head 104.

  Then, with the product cylinder head 106 mounted, the cylinder inner diameter (bore diameter) for each axial position of the cylinder block 102b is measured in the same manner as in step S5 and the like. This measurement data is recorded in the control unit 30, for example, as third inner diameter data (D3). At this time, if a measuring instrument for measuring the inner diameter is inserted from the spark plug insertion hole 106 b formed in the product cylinder head 106, it is not necessary to perform special processing or the like on the product cylinder head 106. .

  When the third inner diameter data (D3) is acquired, the cylinder block 102b that has been bored as described above up to the temperature of the bore 110 of the cylinder block 108 when the actual automobile engine is regularly used. May be heated to measure the cylinder inner diameter (bore diameter). Then, when the data created in the next step S12 is fitted with the product cylinder head 106, the temperature of the cylinder block rises when the engine is actually mounted and used in a car, and the cylinder inner diameter ( This is data created so that the bore diameter) has a desired roundness. When heating the cylinder block 102b as described above, an electromagnetic induction heater (not shown) may be used to heat from the cylinder inner diameter (bore) side. If it does so, it can carry out simple and quick heating, and is suitable.

  Next, in step S12, the third inner diameter data (D3) acquired in step S11 is used as a correction value for the NC data created in step S8, to correct the NC data, and corrected NC data (DN ´). The corrected NC data (DN ′) created in this way is the cylinder inner diameter (bore diameter) when the cylinder block material is bored without mounting the dummy head 104 and then the product cylinder head 106 is mounted. Is data created so as to have a desired roundness.

  According to the boring method in the present embodiment, the dummy head 104 is used by using the modified NC data (DN ′) created as described above in the production process and sequentially boring the cylinder block material. Therefore, it is possible to perform processing to make the cylinder inner diameter (bore diameter) a desired roundness.

  That is, in step S <b> 13, the corrected NC data (DN ′) created in step S <b> 12 is input to the control unit 30 of the composite machine tool 10.

  Next, in step S14, the cylinder block 108, which is a new cylinder block material, is arranged at a predetermined position in the multi-task machine tool 10, and under the control of the control unit 30, the boring process according to the corrected NC data (DN '). Apply.

  As described above, when the boring process is performed using the corrected NC data (DN ′), the bore 110 of the cylinder block 108 is processed in consideration of the deformation after the product cylinder head 106 is mounted ( (See FIG. 15D). That is, by mounting the product cylinder head 106 on the cylinder block 108 processed based on the corrected NC data (DN ′), the bore 110 of the cylinder block 108 can obtain the roundness necessary for the product (FIG. 15E).

  As described above, when the boring process in accordance with the corrected NC data (DN ′) to the cylinder block 108 is completed, a honing process is performed to make the bore 110 have a desired surface roughness.

  That is, in step S15, the honing process using the rough honing grindstone 36 and the finishing honing grindstone 38 is performed on the cylinder block 108. Specifically, first, driving of the first gear set 16 or the second gear set 18 is controlled by the first servo motor 20 or the second servo motor 22 under the control of the control unit 30. Then, the shaft 66 (roughing taper cone 58) or the shaft 68 (finishing taper cone 60) appropriately moves forward and backward to a predetermined position (in the direction of arrow A), so that the expansion force is applied to the roughing honing grindstone 36 and the finishing honing grindstone 38. Or contraction force arises. At this time, the spindle shaft 24 is rotationally driven by the gear 25 and moved forward and backward by the moving mechanism 26. Accordingly, honing is performed on the cylinder block 108 while the rough honing grindstone 36 and the finishing honing grindstone 38 are selected as necessary.

  In this case, since the cylinder block 108 which is a workpiece is machined by the machining head 12 of the composite machine tool 10 of the present embodiment, the cylinder block 108 (workpiece) is clamped by one chucking and then continuously drilled. Thus, honing can be performed without unclamping the clamp. Therefore, the influence of chucking can be reduced, and honing can be performed with high accuracy. In other words, as the number of times of chucking increases, errors in the positioning system at the time of chucking are taken into account, so the machining allowance for the material increases, and if the machining allowance per unit machining time increases, heavy grinding will occur and accuracy will deteriorate. It becomes a trend.

  In this case, in order to further improve the machining accuracy, the air micro detection means 44 detects the amount of change in the bore 110 and the control unit 30 measures the machining elapsed time and the like while measuring the first servo motor 20 and the second servo motor 20. The drive of the servo motor 22 may be controlled. In the composite machine tool 10, by performing processing while accurately changing the expansion force (shrinking force) of the rough honing grindstone 36 and the finishing honing grindstone 38, it is possible to realize a more accurate honing process.

  As described above, according to the composite machine tool 10 according to the present embodiment, the dummy head 104 is produced during mass production (production) by creating the corrected NC data (DN ′) in the boring of the bore of the cylinder block. Since a cylinder block having a desired roundness can be obtained without mounting etc., productivity is greatly improved.

  Further, the expanding operation of the boring bar 42, the rough honing grindstone 36, and the finishing honing grindstone 38 is performed by the first servo motor 20 and the second servo motor 22 via the first gear set 16 and the second gear set 18. It is configured to be For this reason, the control of the expansion position and expansion force of the boring bar 42, the rough honing grindstone 36, and the finishing honing grindstone 38 is easy and highly accurate.

  Further, the honing process can be performed subsequent to the boring process by the rough honing grindstone 36 and the finishing honing grindstone 38 provided coaxially with the boring bar 42, so that the machining accuracy can be further improved.

  By the way, as described above, when the bore 110 of the cylinder block 108 is processed into a desired shape by using the corrected NC data (DN ′), as in the above-described conventional technique, the expansion of the boring bit is controlled by hydraulic pressure. It is difficult to delicately control the expansion force and expansion position of the boring bar. For this reason, in the machine tool having such a configuration, it is difficult to realize the boring method for the bore of the cylinder block according to the present embodiment.

  However, in the composite machine tool 10 according to the present embodiment, the first servo motor 20 and the first gear set 16 are configured to perform expansion control of the shaft 68, that is, the boring tool 42. Therefore, it is possible to perform boring with higher accuracy than the machine tool having the above-described conventional configuration, and it is possible to realize the boring method based on the corrected NC data (DN ′).

  Then, the effect at the time of the boring process by providing the 1st servomotor 20 and the 1st gear set 16 in the composite machine tool 10 is demonstrated next.

  As described above, in the first gear set 16, the ring gear 72 is interposed between the pinion gear 70 connected to the drive shaft 20 a of the first servomotor 20 and the ball screw 74 that actually moves the shaft 68. ing. That is, the pinion gear 70 and the ball screw 74 are not directly meshed by the ball spiral.

  By the way, if the pinion gear 70 and the ball screw 74 are directly meshed with each other by the ball spiral without the ring gear 72 interposed, the first servo motor 20 is intermittently rotated / stopped or forward / reversely rotated. At the time of starting (for example, when starting or stopping), the rotational torque fluctuation transmitted to the pinion gear 70 is transmitted to the ball screw 74 in an irregular state (an unstable jerky state). As a result, the shaft 68 irregularly moves back and forth with poor responsiveness. In other words, when the rotational torque fluctuation transmitted to the pinion gear 70 when the first servomotor 20 intermittently rotates / stops or rotates forward / reversely is transmitted to the ball screw 74 in an irregular state, The pinion gear 70 receives the reaction force and vibrates in the axial direction (arrow A direction). Accordingly, the first servo motor 20 will also vibrate.

  On the other hand, when the rotating pinion gear 70 is connected to the ball screw 74 via the ring gear 72 as in the first gear set 16 in the present embodiment, the first servo motor 20 rotates intermittently. The rotational torque fluctuation transmitted to the pinion gear 70 during stop or forward / reverse rotation is first transmitted to the ring gear 72. Since the ring gear 72 is radially supported by the bearings 82 and 84, the ring gear 72 rotates following the first servomotor 20 in a state where it is affected by irregular fluctuations in rotational torque. Here, the ring gear 72 and the ball screw 74 are meshed by a ball spiral. Accordingly, when the rotation of the ring gear 72 is transmitted to the ball screw 74 under the influence of the irregular fluctuation of the rotational torque, the ring gear 72 receives the reaction force in the axial direction (direction of arrow A). It seems to be vibrated. However, since the ring gear 72 is thrust-supported by the bearings 82 and 84 as described above, it does not vibrate in the axial direction.

  Further, according to the first gear set 16, even if the ring gear 72 vibrates in the axial direction, the ring gear 72 and the pinion gear 70 are connected by a spur gear, and therefore the pinion gear 70 has the shaft described above. Directional vibration is not transmitted. That is, the ring gear 72 functions to block various vibrations in the first gear set 16. Therefore, even if vibration generated in the boring bar 42 due to the uneven shape of the surface to be processed (cutting surface), cutting resistance, or the like is transmitted to the shaft 68, the vibration is blocked by the ring gear 72, and the first servo motor 20 or the like. Will not be transmitted.

  By the way, the irregular rotational torque fluctuation when the first servo motor 20 is intermittently rotated / stopped or rotated / reversed forward can be eliminated by electrical control. The accuracy of the rotational phase control of the first servomotor 20 is not affected. The ring gear 72 can block the vibration from the boring bar 42 and the first servo motor 20 itself does not vibrate. Therefore, it is possible to avoid the occurrence of such inconvenience that the influence of the vibration affects the expansion operation of the boring bar 42.

  Needless to say, the vibration isolation function by the ring gear 72 of the first gear set 16 as described above also acts in the same manner during the honing process. In addition, the second gear set 18 has substantially the same configuration as the first gear set 16 and has the ring gear 88. Therefore, even when honing using the second gear set 18 (rough honing), Of course, it is possible to obtain the action of blocking the vibration as described above. That is, in the composite machine tool 10, the ring gears 72 and 88 function as a vibration isolation mechanism. The first gear set 16 and the second gear set 18 function as power conversion means for converting the rotational power from the first servo motor 20 and the second servo motor 22 into linear power to the shafts 66 and 68.

  It should be noted that the present invention is not limited to the above-described embodiment, and it is naturally possible to adopt various configurations without departing from the gist of the present invention.

  For example, in the machining head 12, the boring bar 42 may be provided on the roughing taper cone 58 side. In addition, for example, a plurality of boring tools 42 may be provided to have different shapes.

  The tip portion of the rough taper cone 58 is not limited to the one divided into the above-mentioned three-forked shape, and may be, for example, a forked shape or a forked shape. In this way, the number of the rough honing grindstone 36 and the finishing honing grindstone 38 can be easily changed.

  Moreover, although the processing method using the flowchart of FIG. 14 was demonstrated as an example of the processing method by the composite machine tool 10 in the said embodiment, the processing method by the composite machine tool 10 is not limited to this method.

It is a partial section schematic block diagram of the compound machine tool concerning the embodiment of the present invention. It is a perspective view of the processing head attached to the composite machine tool. It is a perspective view for demonstrating the internal structure of the said process head. FIG. 3 is a partially omitted perspective view of a rough taper cone in the processing head. FIG. 3 is a perspective view with partial omission of a finishing taper cone in the machining head. FIG. 4 is a cross-sectional view taken along line VI-VI in FIG. 3. FIG. 4 is a cross-sectional view taken along line VII-VII in FIG. 3. It is explanatory drawing for demonstrating the state which extended the biting tool for boring in the said processing head. It is explanatory drawing for demonstrating the state which expanded the rough honing grindstone in the said processing head. It is explanatory drawing for demonstrating the state which expanded the honing grindstone for finishing in the said processing head. It is the partial cross section schematic block diagram which expanded the 1st gear set and 2nd gear set periphery in the said composite machine tool. It is sectional drawing in line XII-XII of FIG. It is a partially-omission cross-sectional perspective view for demonstrating the meshing state of each gear in the said 1st gear set. It is a flowchart for demonstrating the procedure of the boring method and honing method by the said composite machine tool. FIG. 15A is a cross-sectional view for explaining a state in which the dummy head is mounted on the cylinder block, and FIG. 15B is a cross-sectional view for explaining a state after processing the cylinder block with the dummy head mounted. FIG. 15C is a cross-sectional view for explaining a state in which the product cylinder head is mounted on the cylinder block, and FIG. 15D is for explaining a state of the cylinder block after boring without mounting the dummy head. FIG. 15E is a cross-sectional view for explaining a state in which the product cylinder head is mounted on the cylinder block after boring without mounting the dummy head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Composite machine tool 12 ... Processing head 14 ... Work 16 ... 1st gear set 18 ... 2nd gear set 20 ... 1st servo motor 22 ... 2nd servo motor 24 ... Spindle shaft 26 ... Moving mechanism 28 ... Housing 29, 74 , 90 ... Ball screw 30 ... Control unit 32 ... Main body 36 ... Roughening honing stone 38 ... Finishing honing stone 42 ... Boring tool 48 ... Roughing stone shoe 50 ... Finishing grinding wheel shoe 54 ... Cartridge 56 ... Pin 58 ... Coarse taper cone 60 ... Finishing taper cone 66, 68 ... Shaft 70, 86 ... Pinion gear 72, 88 ... Ring gear 72a, 88a ... Spur gear 72b, 88b ... Female screw 74a, 90a ... Male screw 76, 78, 80, 82, 84 , 92, 94, 96, 98, 100 ... bearings 76a, 92a ... inner race 76 , 92b ... outer race 102a, 102b, 108 ... cylinder block 103, 110 ... bore 104 ... dummy head 106 ... Products cylinder head 106b ... spark plug insertion hole

Claims (5)

A hollow spindle shaft rotated by driving means;
A housing that supports the spindle shaft inside;
A shaft that is housed inside the spindle shaft and that is spline-fitted with the spindle shaft so as to be movable back and forth in the axial direction;
A boring tool connected to the tip of the spindle shaft and supported so as to be able to expand and contract in the centrifugal direction and a processing head provided with a honing grindstone;
The machining head is provided with expansion means for expanding the boring bit and the honing grindstone to a predetermined position and with a predetermined expansion force by moving the shaft forward and backward, and the boring bit and the honing A complex machine tool that performs boring and honing by expanding the grinding wheel for
The expansion means includes a servo motor fixed to the housing;
A pinion gear that is rotated by the servo motor or fixed to a desired phase;
An outer peripheral tooth meshes with the pinion gear, a threaded portion is formed on the inner periphery, and a cylindrical ring gear pivotally supported by the housing;
A cylindrical ball screw that is movable in the axial direction of the shaft by engaging a threaded portion formed on the outer periphery with the threaded portion of the ring gear;
It has an inner race fitted to the outer circumference of the shaft and a bearing constituted by an outer race fitted to the inner circumference of the ball screw, and the shaft is configured to be movable forward and backward. A compound machine tool. The compound machine tool according to claim 1,
A plurality of the expansion means and the shaft;
At least one of the shafts corresponding to each expansion means has a hollow shape, and the remaining shaft is inserted through the inside thereof.
The combined machine tool according to claim 1, wherein at least each of the ring gear, the ball screw, and the bearing in each expansion means are arranged on the same axis. A hollow spindle shaft rotated by driving means;
A housing that supports the spindle shaft inside;
A shaft that is housed inside the spindle shaft and that is spline-fitted with the spindle shaft so as to be movable back and forth in the axial direction;
A boring tool connected to the tip of the spindle shaft and supported so as to be able to expand and contract in the centrifugal direction and a processing head provided with a honing grindstone;
The machining head is provided with expansion means for expanding the boring bit and the honing grindstone to a predetermined position and with a predetermined expansion force by moving the shaft forward and backward, and the boring bit and the honing A complex machine tool that performs boring and honing by expanding the grinding wheel for
The expansion machine includes a vibration isolation mechanism, has power conversion means for converting rotational power into linear power, and is configured to be capable of moving the shaft forward and backward. A boring method for a bore of a cylinder block using the composite machine tool according to claim 1 or 3,
The machining head has an opening into which a dummy head simulating a product cylinder head is attached to the cylinder block material before boring, boring is performed, and the inner diameter at each axial position of the bore is measured. A first step of acquiring inner diameter data of 1;
After the first step, the second step of removing the dummy head from the cylinder block, measuring the inner diameter for each axial position of the bore, and obtaining second inner diameter data;
After the second step, by using the first inner diameter data as a correction value of the second inner diameter data, after boring the cylinder block material without mounting the dummy head, A third step of creating NC data so that the bore has a desired roundness when a dummy head is mounted;
After the third step, the NC data is input to the composite machine tool, the cylinder block material is subjected to boring processing according to the NC data, and a product cylinder head is mounted on the cylinder block after the boring processing. Measuring the inner diameter of each bore axial position and obtaining third inner diameter data;
After the fourth step, the NC data is corrected by using the third inner diameter data as a correction value, and after boring the cylinder block material without mounting the dummy head, a product cylinder A fifth step of creating corrected NC data so that the bore has a desired roundness when the head is mounted;
A boring method for a bore of a cylinder block, comprising: In the boring method of the bore of the cylinder block according to claim 4,
A boring method for a bore of a cylinder block, wherein a measuring instrument is inserted from a spark plug insertion hole provided in the product cylinder head when measuring the inner diameter in the fourth step.

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