JP2008069931A - Connecting rod manufacturing method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To highly accurately form an oil hole in a connecting rod manufactured by breaking separation. <P>SOLUTION: A division machining device 50 comprises a movable stage 64 provided freely close to or apart from a fixed stage 62, a first mandrel 114 detachably provided on the side of the fixed stage 62 and located on the side of a rod portion 34 and a second mandrel 120 detachably provided on the side of the movable stage 64 and located on the side of a cap portion 32 to be displaced integrally with the movable stage 64, a pair of wedge members 122a, 122b provided on both sides between the first and second mandrels 114, 120 for moving the movable stage 64 apart from the fixed stage 62 with a load imparted thereto by a loading mechanism 58, and an oil hole machining mechanism 59 including a moving mechanism part 83 for moving the movable stage 64 in the direction of being apart from the fixed stage 62, and a turning mechanism part 85 for turning the fixed stage 62 in the direction of intersecting the direction of being apart therefrom. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for manufacturing a connecting rod constituting, for example, a vehicle engine component, and more specifically, after integrally forming a connecting rod having a large end and a small end, the large end The present invention relates to a method and apparatus for manufacturing a connecting rod in which a cap portion and a main body portion are broken and divided, and a lubricating oil supply hole is formed at the large end portion.

  2. Description of the Related Art Conventionally, for example, a connecting rod (connecting rod) that connects a piston pin and a crank pin has been widely used in a vehicle engine. The connecting rod has a large end connected to the crank pin and a small end connected to the piston pin.

  In Patent Document 1, a rod part including a part of the small end part and the large end part and a substantially U-shaped cap part composed of the remaining part of the large end part are individually manufactured, and then a pair of them is manufactured. An assembly-type connecting rod that is integrally assembled with a bolt is disclosed. In this assembly type connecting rod, the cap portion can be assembled to the rod portion with high accuracy by fitting positioning pins into the pin holes respectively formed in the rod portion and the cap portion.

  However, in this type of assembly-type connecting rod, after the rod part and the cap part are individually forged, bolt holes are drilled in the two parts of the rod part and the cap part, respectively. It is necessary to process the mating surface of the cap part into a flat surface. For this reason, processing man-hours increased and it was difficult to improve production efficiency.

  Therefore, in order to avoid such inconvenience, after integrally forming the connecting rod from the large end portion to the small end portion, for example, by forging, the large end portion is broken and divided into a cap portion and a rod portion. A fracture split type connecting rod has been proposed.

  As an apparatus for breaking and dividing a connecting rod, for example, Patent Document 2 discloses a set of external pressures for applying an external pressure to an internal pressure applied to a bearing hole of a bearing part of a connecting rod and an external pressure to the bearing part. An internal pressure at which the external pressure is applied to the bearing portion by the set of external pressure applying devices, the internal pressure is applied to the bearing portion by the internal pressure applying device, and the internal pressure by the internal pressure applying device can divide the bearing portion. An apparatus is disclosed in which the external pressure of the external pressure applying device is instantaneously released and the bearing portion is instantaneously divided by the internal pressure.

  Further, Patent Document 3 discloses first and second support members that are disposed on a base of a pallet on which a connecting rod is placed so as to be movable away from each other and horizontally support the connecting rod, A half mandrel comprising mandrel halves that are suspended from the first and second support members and each outer peripheral surface abuts against the inner surface of the opening, and surfaces that abut the opposing end surfaces of the mandrel halves are respectively tapered surfaces A wedge that evenly separates and expands each mandrel half, an actuator that applies a load to the wedge, an initial load applied to the actuator, and the mandrel half abuts against the inner surface of the opening, and then breaks. A connecting rod breaking device including a control circuit that momentarily breaks an opening by applying a load is disclosed.

  Next, regarding this type of fracture of the connecting rod, for example, Patent Document 4 discloses that the pair of semi-cylindrical protrusions on both sides in the axial direction of the pair of semi-cylindrical protrusions fitted in the large end holes of the connecting rod. Disclosed is a connecting rod splitting device in which it is possible to prevent distortion of a large end hole after splitting by uniformly applying a destructive force in a direction in which they are separated from each other.

  The large end portion of such a fracture split type connecting rod has a notch (groove) as a break line, and is in a direction perpendicular to the longitudinal direction of the connecting rod at a substantially central portion of the through hole (joining hole) of the large end portion. By breaking, the connecting rod is divided into a rod portion and a cap portion. In this case, the fracture surface on the rod part side and the fracture surface on the cap part side have an uneven shape and an uneven shape, respectively, so that when the pair of bolts are attached, they are in close contact, so the rod part and the cap part are highly accurate. Can be assembled. In other words, the fracture split type connecting rod does not use positioning pins like the assembly type connecting rod, so each of the concave and convex fracture surfaces on the rod side and cap side is brought into close contact with each other with high precision. It is necessary to meet.

  However, when the rod part and the cap part are assembled, if the shape of the rugged fracture surface or the rugged fracture surface is destroyed, not only can the positioning function be achieved as a mating surface, but also the Unnecessary gaps may be generated, causing abnormal noise, and may adversely affect the roundness of the coupling hole at the large end.

  Furthermore, the residual stress generated after the fracture splitting causes a contraction phenomenon in the rod part and the cap part (in general, the contraction on the cap part side tends to be larger than the contraction on the rod part side). The contraction phenomenon may cause displacement between the fracture surface on the rod side and the fracture surface on the cap side, and it may be difficult to perform accurate surface matching. When the connecting rod is broken and divided into the rod portion and the cap portion, an elongation (expansion) phenomenon may occur in the rod portion and the cap portion due to residual stress generated after the breaking division.

  By the way, in the connecting rod, an oil hole that penetrates from the inner diameter side on the crankshaft side to the outer diameter side on the piston side is formed in the large end portion, and the oil from the crankshaft side is passed through the large end portion to the piston. Injecting to the side is performed (refer patent document 5).

  Such oil hole machining requires high-precision machining in order to accurately inject oil and prevent the generation of noise due to the space with the crankshaft.

Japanese Patent Laid-Open No. 11-2230 Japanese Patent Laid-Open No. 10-277848 JP 2002-66998 A JP-A-6-42527 JP 2001-241426 A

  However, in a fracture split type connecting rod, when shrinkage or elongation occurs due to the residual stress as described above on the rod part side where the oil hole is formed, the amount of shrinkage or elongation is not constant, and it varies greatly from individual to individual. Will have. Therefore, it is difficult to make the jig used for forming the oil hole common, and when correcting the shrinkage and elongation, adjustment for each individual is required, and the manufacturing process is not only complicated. There is also a concern that the uneven (uneven) fracture surface is damaged, and there is a concern that the assembling property between the rod part and the cap part may be adversely affected.

  The present invention has been made in consideration of the above-described conventional problems, and has a concavo-convex fracture surface, and further, for a fracture split type connecting rod that may cause expansion and contraction of the rod part (main body part), It is an object of the present invention to provide a connecting rod manufacturing method and apparatus capable of forming an oil hole (lubricating oil supply hole) with high accuracy.

  In order to achieve the above object, the manufacturing method of a connecting rod according to the present invention comprises: integrally forming a connecting rod having a large end and a small end; Connecting the expansion end to break the large end portion into a cap portion and a main body portion, and then to form a lubricating oil supply hole penetrating the large end portion in the main body portion A rod manufacturing method, wherein the main body portion side is fixed by one of the extension tool and the first stage, and the cap portion side is fixed by the other extension tool and the second stage, and the cap portion And the main body portion, the lubricating oil supply hole is formed by separating the main body portion and the cap portion by a predetermined distance in a state where at least the main body portion side is fixed.

  According to such a manufacturing method, by processing the lubricating oil supply hole in a state in which the main body portion of the connecting rod fractured and divided by the one set of extension tools is fixed by one of the extension tools, For example, since it is not necessary to transfer the main body part to a separately prepared jig for processing a lubricating oil supply hole, even if the main body part contracts or expands due to residual stress caused by fracture splitting, Lubricating oil supply holes can be formed with high accuracy, and work efficiency can be improved. In addition, it is possible to avoid the inconvenience that the fractured surface formed by the fracture division is damaged during the transfer.

  Further, in the connecting rod manufacturing method of the present invention, when the tool is guided through the guide portion provided in the one extension tool for fixing the main body portion and the lubricating oil supply hole is formed, for example, A tool such as a drill is accurately guided by the guide portion to a position where the lubricating oil supply hole of the main body portion is to be formed, and the drilling direction of the tool during processing is also accurately guided. Therefore, it is possible to form the lubricating oil supply hole with higher accuracy.

  In the connecting rod manufacturing apparatus of the present invention, after integrally forming a connecting rod having a large end and a small end, the coupling hole of the large end is set in a set of expansion tools, and the expansion tool is expanded. A connecting rod manufacturing apparatus for breaking and dividing the large end portion into a cap portion and a main body portion, and a fixed stage fixed on a base, and disposed opposite to the fixed stage along a horizontal direction. A movable stage that is provided so as to be close to or away from the fixed stage, a main body-side expansion tool that is detachably provided on the fixed stage, and a detachable provided on the movable stage. Provided between the fixed stage and the movable stage, and is inserted between the fixed stage and the movable stage. A wedge member for separating the wedge, a load mechanism for applying a breaking load in the press-fitting direction of the wedge member in order to break and divide the large end portion, and at least one of the fixed stage or the movable stage as the other And a lubricating oil supply hole machining mechanism that displaces or rotates at least one of the fixed stage or the movable stage in a direction intersecting the separation direction. To do.

  In this case, by providing the lubricating oil supply hole machining mechanism, after the connecting rod is broken and divided by the set of expansion tool, load mechanism, etc., the main body portion is subsequently fixed by one expansion tool. The lubricating oil supply hole can be processed as it is. Therefore, since it is not necessary to transfer the main body portion after the fracture splitting to, for example, a separately prepared jig for processing a lubricating oil supply hole, the main body portion contracts or expands due to residual stress generated by the fracture splitting. Even in this case, the lubricating oil supply hole can be formed with high accuracy and the work efficiency can be improved. In addition, it is possible to avoid the inconvenience that the fractured surface formed by the fracture division is damaged during the transfer.

  Further, in the connecting rod manufacturing apparatus of the present invention, the one extension tool on the main body portion side has a guide portion for guiding a tool for forming a lubricating oil supply hole penetrating the large end portion in the main body portion. When provided, for example, a tool such as a drill is accurately guided by the guide portion to a position where the lubricating oil supply hole of the main body portion is to be formed, and also accurately in the drilling direction of the tool during processing. Be guided to. Therefore, it is possible to form the lubricating oil supply hole with higher accuracy.

  According to the present invention, it is possible to continuously process the lubricating oil supply hole in a state where the main body portion of the connecting rod that has been divided by fracture is fixed by the expansion tool. That is, since it is not necessary to transfer the main body after the fracture splitting to, for example, a separately prepared jig for processing a lubricating oil supply hole, the main body contracts or expands due to the residual stress generated by the fracture splitting. Even in this case, the lubricating oil supply hole can be formed with high accuracy and the work efficiency can be improved. Moreover, it can avoid that the torn surface formed by the said fracture | rupture division | segmentation is damaged at the time of the said transfer.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a connecting rod according to the present invention will be described in detail with reference to the accompanying drawings by giving preferred embodiments in relation to a manufacturing apparatus for carrying out the method.

  FIG. 1A is a perspective view of a connecting rod 30 as a workpiece to which the present invention is applied. FIG. 1B shows a state in which the connecting rod 30 is divided into a cap portion 32 and a rod portion (main body portion) 34 by breaking. 1C is a perspective view in which the top and bottom of the connecting rod 30 shown in FIG. 1B is inverted.

  The connecting rod 30 includes a large end portion 38 in which a cap portion 32 and a rod portion 34 are integrally formed via a substantially circular coupling hole 36, and a small end portion disposed on the opposite side of the large end portion 38. And an end 40. The connecting rod 30 is integrally formed by casting or forging, for example.

  Bolt holes 42a and 42b are formed on both sides of the large end portion 38 of the connecting rod 30 by a drilling mechanism (not shown) such as a drill, for example. In these bolt holes 42a and 42b, for example, in an assembly process of an engine or the like, bolts (not shown) are respectively screwed from the cap portion 32 side, and the cap portion 32 is fastened to the rod portion 34. In this manner, the cap portion 32 and the rod portion 34 that are divided by breaking are integrally fastened, whereby the large end portion 38 of the connecting rod 30 is connected to the crank pin of the engine.

  The rod portion 34 is formed with an oil hole (lubricating oil supply hole) 41 penetrating the large end portion 38 so as to communicate the inner diameter side (inner wall side) and the outer diameter side (outer wall side) of the coupling hole 36. The The oil hole 41 is a small-diameter through hole oriented in the radial direction from the approximate center of the coupling hole 36, and oil (lubricating oil) from the crankpin side is connected to a piston (not shown) connected to the small end 40. And fulfills the function of injecting (supplying).

  In FIG. 1A, reference numeral 44 indicates a divided portion that is a boundary portion between the cap portion 32 and the rod portion 34 in the large end portion 38. The dividing portion 44 is set on both sides of the large end portion 38 at portions facing the coupling hole 36 as a center.

  Next, the division | segmentation processing apparatus 50 which concerns on embodiment of this invention is shown to FIGS. 2 is a partially exploded perspective view of the division processing apparatus 50, FIG. 3 is a partial sectional plan view of the division processing apparatus 50 shown in FIG. 2, and FIG. 4 is a partial longitudinal section along the axial direction of FIG. FIG.

  The split machining apparatus 50 is set with the connecting rod 30 positioned at a predetermined position, and includes a workpiece positioning holding mechanism 52 for holding the set connecting rod 30 and a large end portion 38 of the connecting rod 30. A break splitting mechanism 54 for splitting at break and a load mechanism 58 for applying a preload and a break load to the break splitting mechanism 54 by functioning as an actuator by the driving force of the hydraulic cylinder. Further, the split processing device 50 has an oil hole processing mechanism (lubricating oil supply hole processing mechanism) 59 for forming the oil hole 41 in the connecting rod 30 that is broken and divided.

  The work positioning and holding mechanism 52 is formed in a substantially rectangular shape when viewed from above, and is configured to be separable into a rotating part 60a and a moving part 60b in a direction substantially perpendicular to the axial direction at a substantially central part in the axial direction. 60, a fixed stage (first stage) 62 fixed on the rotating portion 60 a of the base 60, and an axial direction of the base 60 with respect to the fixed stage 62 arranged to face the fixed stage 62. And a movable stage (second stage) 64 provided on the moving part 60b of the base 60 so as to be able to approach or separate in the horizontal direction along the axis. Further, a first bracket 66 and a second bracket 68 are fixed to both ends of the base 60 so as to protrude outward in the axial direction of the base 60. The base 60 is supported on a base support 69 that constitutes the oil hole machining mechanism 59.

  The fixed stage 62 includes a fixed table 70 fixed to the rotating portion 60a of the base 60 via a first bracket 66, a first hydraulic cylinder 72 fixed to the fixed table 70, and the first hydraulic pressure. A movable block 76 that is connected to the tip of the piston rod 72a of the cylinder 72 and is movable along the guide rail 74 along the axial direction of the connecting rod 30, and a predetermined length from the end of the movable block 76. It is fixed to the groove portion of the movable block 76 so as to protrude, and engages with the small end portion 40 of the connecting rod 30 under the driving action of the first hydraulic cylinder 72 so that the small end portion 40 is large along the axial direction. And a first work support member 78 that presses toward the end portion 38 side.

  The first hydraulic cylinder 72 switches the small end portion 40 of the connecting rod 30 along the axial direction by switching the pressure of the supplied pressure oil between a low pressure and a high pressure under the switching action of a switching valve (not shown). The force (thrust) pressing toward the portion 38 side can be switched.

  As shown in FIGS. 2 and 5, a tapered engagement portion 80, which is recessed in a v-shaped cross section that engages with the small end portion 40 of the connecting rod 30, is provided at the distal end portion of the first work support member 78. Is formed.

  Further, the fixed stage 62 is slid along a pair of guide bars 82a and 82b fixed substantially in parallel on the fixed table 70 with the movable block 76 therebetween, and the guide bars 82a and 82b. The slider 86 is provided so as to be movable back and forth with respect to the connecting rod 30 via a pair of guide blocks 84, and a first air cylinder 88 fixed to the fixed table 70 and moving the slider 86 forward and backward.

  The slider 86 includes a second air cylinder 94 that is rotatably provided at a predetermined angle with a first pin 92 pivotally attached to a pair of bearing blocks 90a and 90b as a fulcrum, and a bifurcated branch portion. The joint member 96 connected to the piston rod 94a of the second air cylinder 94 and one end portion thereof are pivotally mounted between the branch portions of the joint member 96 via the second pin 98, and the central portion is connected to the third pin 100. And a second work support member 104 pivotally supported on the connecting plate 102 of the slider 86.

  A pressing portion 104 a having a substantially Y shape is provided at the distal end portion of the second work support member 104. As shown in FIG. 6, the pressing portion 104 a swings (rotates) at a predetermined angle with the third pin 100 as a rotation fulcrum under the driving action of the second air cylinder 94, thereby connecting rod 30. It has a function of pressing the upper surface portion of the large end portion 38 (rod portion 34) downward and holding the connecting rod 30.

  On the rotating part 60a of the base 60 close to the fixed table 70, as shown in FIG. 5, there is a fixed block 108 protruding in a bifurcated shape with a concave section 106 having a rectangular cross section in between. Fixed. The concave portion 106 of the fixing block 108 is provided with a positioning fixing pin 110 that positions and holds the end portion of the connecting rod 30 through the hole of the small end portion 40.

  In this case, when the first work support member 78 enters from the horizontal direction along the concave section 106 having a rectangular cross section of the fixed block 108, the axes of the first work support member 78 and the connecting rod 30 coincide with each other. Thus, the engaging portion 80 formed at the distal end portion of the first work support member 78 is guided so as to be surely engaged with the small end portion 40 of the connecting rod 30.

  Further, as shown in FIGS. 4 and 6, a holding block 112 fixed on the rotating portion 60 a of the base 60 is provided between the fixed block 108 and the movable stage 64, and the holding block The first connection block 107 a is fixed on the 112. A first mandrel 114 having a semicircular convex portion that contacts the opening of the large end portion 38 is detachably provided on the first connecting block 107 a via a mounting screw 111. That is, as shown in FIG. 7, the first connection block 107 a fixed to the fixed stage 62 side is formed with a substantially semicircular recess 109 a in a portion adjacent to the movable stage 64, and the first mandrel 114 is formed in the first mandrel 114. A mounting screw 111 inserted through the formed flange 114a is detachable and can be replaced with another mandrel.

  The convex portion of the first mandrel 114 is provided with a guide hole (guide portion) 105 having a function of guiding the tool 103 when the oil hole 41 is formed in the large end portion 38 (see FIG. 7 and FIG. 7). (See FIG. 8). The guide hole 105 is a through-hole oriented in the radial direction and along the horizontal direction from the approximate center of the convex portion of the first mandrel 114. The guide hole 105 accurately guides the tool 103 to a position where the oil hole 41 of the rod portion 34 is to be formed in a state where the rod portion 34 of the connecting rod 30 is fixed to the first mandrel 114, and It fulfills the function of accurately guiding the direction of machining by the tool 103. Needless to say, a similar guide hole 105 is provided in another mandrel exchanged with the first mandrel 114.

  In addition, a pair of long grooves 113a and 113b having a rectangular cross section in which a pair of wedge members 122a and 122b slide are respectively provided on one side surface of the holding block 112 and the first connection block 107a facing the movable stage 64. The first mandrel 114 is formed on both sides with a predetermined distance between them and extending along the vertical direction. Guide plates 115 for guiding the wedge members 122a and 122b are mounted in the pair of long grooves 113a and 113b, respectively.

  As shown in FIGS. 2 and 3, a pair of first guide elements 116 a and 116 b for guiding the movable stage 64 along the axial direction of the connecting rod 30 are provided on the moving part 60 b of the base 60. Fixed in parallel. Each of the pair of first guide elements 116a and 116b is formed with a long groove extending in the axial direction between the upper surface of the base 60, and the flange portion 118a of the slide block 118 slides on the long groove. It is provided to move.

  4 and 6, a second connection block 107b is fixed to the upper surface of the slide block 118, and the second connection block 107b has a semicircular shape that contacts the opening of the large end portion 38. A second mandrel 120 having a convex portion is detachably provided via a mounting screw 111. That is, as shown in FIG. 7, the second connecting block 107 b fixed to the movable stage 64 side is formed with a substantially semicircular recess 109 b in a portion adjacent to the movable stage 64, and the second mandrel 120 has A mounting screw 111 inserted through the formed flange 120a is detachable and can be replaced with another mandrel.

  The second mandrel 120 is disposed so as to approach or be separated from the first mandrel 114 on the fixed stage 62 side by a predetermined distance by being displaced integrally with the movable stage 64. Each of the first and second mandrels 114 and 120 having a semicircular convex portion functions as a set of expansion tools.

  In this case, the semicircular convex portions of the first and second mandrels 114 and 120 are combined to form a circular convex portion, and the large end portion 38 of the connecting rod 30 is connected to the circular convex portion. The coupling hole 36 is set (see FIG. 3). The outer diameter of the circular convex portion formed by combining the first and second mandrels 114, 120 is set in advance corresponding to the inner diameter of the coupling hole 36 of the connecting rod 30, For example, in the case of different types of connecting rods, since the inner diameters of the coupling holes are different, other first and second mandrels (not shown) are mounted via mounting screws.

  Further, a connecting plate 124 erected along the vertical direction is fixed to the end of the slide block 118, and a set of third air cylinders 126a and 126b are arranged on the connecting plate 124 along the horizontal direction at a predetermined interval. They are connected at a distance (see FIG. 3). A pair of third work support members 130a and 130b are coupled to the tip ends of the piston rods of the third air cylinders 126a and 126b via a shaft 128. The set of third work support members 130a and 130b can advance and retreat on the plane of the second mandrel 120 along the axial direction of the connecting rod 30 under the driving action of the set of third air cylinders 126a and 126b, respectively. Provided.

  As shown in FIGS. 3 and 4, one end portion of the pair of third work support members 130 a and 130 b along the axial direction abuts against the cap portion 32 of the large end portion 38 of the connecting rod 30, A pair of protrusions 132 are provided for pressing the connecting rod 30 from the large end 38 toward the small end 40 in parallel with the axial direction. An inclined surface 138 that engages with a pressing surface 136 of fourth work support members 134a and 134b, which will be described later, is provided at the other end of the third work support members 130a and 130b on the opposite side of the protrusion 132.

  In this case, the set of third work support members 130a and 130b is, as shown in FIGS. 2 and 3, two sets of second guides fixed substantially parallel to the upper surface of the planar portion of the second mandrel 120. It is provided so as to be displaced linearly along the axial direction of the connecting rod 30 by the guiding action of the elements 140a to 140d.

  Furthermore, a fixed plate 141 is provided on the upper surface of the slide block 118, and a pair of second hydraulic cylinders 146a and 146b are fixed above the fixed plate 141 via a top plate 144 supported by a support portion 142. (See FIG. 2). A set of fourth work support members 134a and 134b each formed of a substantially cubic block body is connected to the tip of the piston rod of the set of second hydraulic cylinders 146a and 146b, and the fourth work support member 134a. , 134b are provided to be displaceable along the vertical vertical direction.

  The set of second hydraulic cylinders 146a and 146b respectively switch the pressure of the supplied pressure oil between a low pressure and a high pressure under the switching action of a switching valve (not shown), thereby setting a set of third work support members 130a. , 130b can be switched between the forces (thrust force) for pressing the connecting rod 30 toward the cap portion 32 side.

  One side surface of the fourth work support members 134a and 134b is engaged with the inclined surface 138 of the third work support members 130a and 130b and presses the third work support members 130a and 130b toward the connecting rod 30 side. A pressing surface 136 is formed.

  As shown in FIG. 3, the support portion 142 is erected and fixed on the upper surface of the fixing plate 141, and is a set of first sets extending substantially parallel to the axis of the connecting rod 30 at a predetermined interval. Support plates 142a, 142b, a second support plate 142c connected to the upper side walls of the pair of first support plates 142a, 142b so as to be horizontally mounted along the horizontal direction, and the second support plate 142c. And a pair of third support plates 142d and 142e connected substantially in parallel along the vertical plane.

  The third support plates 142d and 142e are formed with a pair of convex portions 148 extending substantially parallel to the vertical direction, and the concave portions 150 and the convex portions respectively formed on the fourth work support members 134a and 134b. When the part 148 is engaged, the fourth work support members 134a and 134b are smoothly guided along the vertical direction.

  Further, the reaction force when the pressing surface 136 of the fourth workpiece support members 134a and 134b engages with the inclined surface 138 of the third workpiece support members 130a and 130b and presses the third workpiece support members 130a and 130b, It is suitably supported by a pair of third support plates 142d and 142e via first support plates 142a and 142b that are erected along the vertical direction.

  The first side wall portion 68a of the second bracket 68 protruding outward from the moving portion 60b of the base 60 is connected to the connecting plate 124 at the tip end portion of the first piston rod 152a to connect the entire movable stage 64. A fourth air cylinder 152 that is displaced along the axial direction of the rod 30 is fixed.

  The fourth air cylinder 152 is configured by a double rod type in which each of the first piston rod 152a and the second piston rod 152b protrudes from both end portions along the axial direction of the cylinder tube. In this case, the first piston rod 152a is fixed to the connecting plate 124 connected to the slide block 118, and the second piston rod 152b is provided as a free end.

  A pair of backup cylinders 153 and 155 are fixed to the first side wall 68a of the second bracket 68 on both sides of the fourth air cylinder 152. The distal ends of the piston rods 153a and 155a of the set of backup cylinders 153 and 155 are respectively connected to the connecting plate 124, and the entire movable stage 64 is displaced along the axial direction of the connecting rod 30, as will be described later. The fracture surface of the cap portion 32 that is displaced integrally with the movable stage 64 is provided so as to abut the fracture surface of the rod portion 34 on the fixed side.

  A fifth air cylinder 154 is fixed to the second side wall 68 b of the second bracket 68. The end of the piston rod 154 a of the fifth air cylinder 154 is provided so as to be able to contact the second piston rod 152 b of the fourth air cylinder 152. By driving the fifth air cylinder 154 and extending the piston rod 154a, it abuts on the second piston rod 152b of the fourth air cylinder 152 and presses the entire movable stage 64 to displace it along the horizontal direction. Can do.

  As shown in FIG. 2, the breaking and dividing mechanism 54 is mutually connected to the first and second mandrels 114 and 120 having a pair of semicircular projections in which the coupling hole 36 of the large end 38 is set. A pair of wedge members 122a and 122b that are pressed into each other to transmit the separation force and expand the fixed stage 62 and the movable stage 64 in a direction to separate each other are provided.

  The pair of wedge members 122a and 122b are interposed at a boundary portion between the fixed stage 62 and the movable stage 64, and on both sides of the semicircular convex portions of the first and second mandrels 114 and 120. Each is arranged. The movable stage 64 is formed with a pair of long grooves 117a and 117b in which the wedge members 122a and 122b slide corresponding to the long grooves 113a and 113b of the fixed stage 62 (see FIG. 3).

  The wedge members 122a and 122b have tapered surfaces that widen toward the tip portions. The tapered surfaces are in sliding contact with the wall surfaces of the long grooves 117 a and 117 b of the movable stage 64, so that the wedge members 122 a and 122 b are in the long grooves 113 a, 113 b, 117 a and 117 b facing the fixed stage 62 and the movable stage 64. Inserted. Therefore, when the pair of wedge members 122a and 122b are urged substantially simultaneously downward in FIG. 4 by the load mechanism 58, the sliding action between the tapered surface and the long grooves 117a and 117b on the movable stage 64 side, The movable stage 64 is expanded in a direction away from the fixed stage 62 while sliding.

  The load mechanism 58 includes hydraulic cylinders 55a and 55b, and piston rods 53a and 53b of the hydraulic cylinders 55a and 55b are connected to the pair of wedge members 122a and 122b, respectively (see FIGS. 4 and 6). . Accordingly, the pair of wedge members 122a and 122b are displaced (pulled) downward via the piston rods 53a and 53b by the driving force of the hydraulic cylinders 55a and 55b, whereby the wedge members 122a and 122b are moved. A breaking load for breaking the connecting rod 30 can be applied.

  Further, the load mechanism 58 includes storage boxes 57a and 57b that store the hydraulic cylinders 55a and 55b, respectively, and third brackets 61a that fix the storage boxes 57a and 57b to the lower surface of the rotating portion 60a of the base 60, respectively. 61b. Therefore, the load mechanism 58 is integrally fixed to the rotating portion 60a.

  In addition, such a load mechanism should just be the structure which can urge | bias the said wedge members 122a and 122b below.

  The oil hole machining mechanism 59 has a base support 69 configured to be substantially U-shaped when viewed from the side and supporting the base 60 (see FIG. 4). Further, the oil hole machining mechanism 59 includes a moving mechanism portion 83 that moves the moving portion 60b of the base 60 forward and backward in the horizontal direction along the axial direction of the base 60, and a rotating portion 60a of the base 60. A rotation mechanism unit 85 that swings (rotates) at a predetermined angle with a rotation shaft 81 projecting from the lower surface of the rotation unit 60a in the horizontal direction along the axial direction of the table 60 as a rotation fulcrum.

  The base support 69 has a first support portion 69a that slidably and rotatably supports the rotating portion 60a of the base 60 on the upper surface, and a movable portion 60b of the base 60 that is slidable on the upper surface. A second support portion 69b supported by the first support portion 69a, a recess 69c formed between the first support portion 69a and the second support portion 69b, and an opening toward the upper surface and the side surface slightly above the center of the first support portion 69a. And a space portion 69d in which the rotating mechanism portion 85 is installed.

  Furthermore, as shown in FIG. 9, an arcuate guide groove 69 e centering on the rotation shaft 81 is formed on the upper surface of the first support portion 69 a of the base support body 69. The guide groove 69e is rotated about the rotation shaft 81 of the rotating portion 60a by inserting a guide pin 87 projecting from the lower surface of the rotating portion 60a of the base 60 so as to be slidable. It plays the function of guiding the movement.

  As shown in FIG. 2, the moving mechanism 83 is formed on the upper surface of the second support 69 b of the base support 69 from the corner of the moving 60 b of the base 60 as viewed from above. A motor 89 that is spaced apart in the axial direction, a ball screw 91 that is connected to the drive shaft of the motor 89 and extends in the horizontal direction along the axial direction of the base 60, and the base 60 It has a nut member 93 fixed to the upper surface of the moving part 60b and screwed into the ball screw 91. The motor 89 is constituted by a servo motor, for example.

  The moving mechanism 83 has a pair of guide bars 95a and 95b that are in contact with both side surfaces of the moving part 60b and extend in the axial direction of the base 60 (see FIG. 3).

  Accordingly, when the motor 89 is driven to rotate and the ball screw 91 is driven to rotate, the moving part 60b of the base 60 follows the axial direction of the base 60 under the guiding action of the guide bars 95a and 95b. In the horizontal direction, the base 60 moves forward and backward so as to approach or separate from the rotating portion 60a (see FIGS. 3 and 12).

  As shown in FIGS. 4 and 6, the rotation mechanism 85 is disposed in the space 69 d. The rotation mechanism unit 85 includes a motor 97 and a gear body 99 connected to the tip of a drive shaft 97a of the motor 97. The motor 97 is constituted by a servo motor, for example. The gear body 99 is provided so as to be able to mesh with a gear body 101 connected to the tip of the rotating shaft 81. These gear bodies 99 and 101 are constituted by spur gears, for example.

  Accordingly, the rotational driving force of the motor 97 is rotated from the gear body 99 through the gear body 101 in a state where the moving section 60b of the base 60 is separated from the rotating section 60a by a predetermined distance by the moving mechanism section 83. When transmitted to the shaft 81, the rotating portion 60a of the base 60 rotates (swings) a predetermined angle about the rotating shaft 81 under the guiding action of the guide groove 69e and the guide pin 87. (See FIG. 12).

  The connecting rod splitting device 50 according to the embodiment of the present invention is basically configured as described above. Next, the operation and effect of the connecting rod are shown in the flowcharts shown in FIGS. The details will be described below.

  First, the integrally formed connecting rod 30 is set on the workpiece positioning and holding mechanism 52 (see FIG. 4). At that time, the connecting rod 30 is positioned on the small end 40 side by the positioning fixing pin 110, and the coupling hole 36 of the large end 38 is formed into a circular convex portion where the first and second mandrels 114 and 120 are combined. It is set so as to be fitted (step S1).

  The connecting rod 30 set in this way is held at a predetermined position via the workpiece positioning holding mechanism 52. That is, by driving the first hydraulic cylinder 72, the movable block 76 connected to the tip of the piston rod 72a is displaced toward the connecting rod 30 side under the guide action of the guide rail 74. The first work support member 78 fixed to the groove portion of the movable block 76 engages with the small end portion 40 of the connecting rod 30 and presses the small end portion 40 toward the large end portion 38 along the axial direction. (Step S2).

  In this case, as shown in FIG. 5, the first work support member 78 advances in the horizontal direction along the concave portion 106 having a rectangular cross section that branches into a bifurcated shape of the fixed block 108. An engaging portion 80 having a v-shaped cross section formed at the distal end portion of the support member 78 is guided so as to engage with the small end portion 40 of the connecting rod 30 in a coaxial state along the axial direction.

  Subsequently, by driving the pair of third air cylinders 126a and 126b, respectively, the pair of third work support members 130a and 130b connected to the tip end portion of the piston rod via the shaft 128 becomes the second guide. It slides and displaces along the axial direction of the connecting rod 30 under the guiding action of the elements 140a to 140d. Accordingly, the protrusions 132 of the pair of third work support members 130a and 130b abut against both shoulders of the cap portion 32 of the connecting rod 30, and the connecting rod 30 is moved from the large end portion 38 to the small end portion 40 side. By pressing along the axial direction, both shoulder portions of the cap portion 32 are supported from the lateral direction (horizontal direction) (step S3).

  In this case, the protrusions 132 of the third work support members 130a and 130b abut against both shoulders of the cap portion 32 of the connecting rod 30 so that the inclination (axis) of the connecting rod 30 is set in a predetermined positioning direction. Is slightly pressed (correction with respect to the axial direction of the connecting rod 30).

  Subsequently, by driving the second air cylinder 94 and extending the piston rod 94a connected to the joint member 96, the second work support member 104 has a predetermined angle toward the lower side with the third pin 100 as a rotation fulcrum. (See FIG. 6). When the second workpiece support member 104 is rotated by a predetermined angle, the tip end of the substantially Y-shaped pressing portion 104a comes into contact with the upper surface of the large end portion 38 near the coupling hole 36 of the connecting rod 30 at two points. The large end portion 38 is pressed downward (step S4).

  As a result, the rod portion 34 of the connecting rod 30 is fixed to the fixing pin 110 and the first pin under the pressing action of the first work support member 78 in the horizontal direction and the pressing action of the second work support member 104 in the downward direction. The locked state is completely fixed to the one mandrel 114.

  In this case, the convex portions of the first and second mandrels 114 and 120 engage with the coupling hole 36 on the large end portion 38 side of the connecting rod 30, and the positioning fixing pin 110 in the hole portion on the small end portion 40 side. And the seating confirmation mechanism (not shown) confirms that the connecting rod 30 is seated on the flat portion of the upper surface of the first mandrel 114 (step S5).

  Specifically, for example, as a seating confirmation mechanism, an air discharge hole is provided in the flat portion on the upper surface of the first mandrel 114, and the connecting rod 30 is seated on the flat portion of the first mandrel 114, thereby closing the air discharge hole. Thus, it is confirmed that the connecting rod 30 is securely seated by detecting by a sensor (not shown) that the air discharge flow rate has decreased (the air discharge pressure from the air discharge hole has decreased).

  Next, the hydraulic cylinders 55a and 55b of the load mechanism 58 are driven to move the piston rods 53a and 53b downward, and a preliminary load is applied to the wedge members 122a and 122b via the piston rods 53a and 53b (step). S6).

  Accordingly, the wedge members 122a and 122b are press-fitted between the long grooves 113a, 113b, 117a, and 117b formed between the fixed stage 62 and the movable stage 64, and the wall surfaces of the long grooves 117a and 117b of the movable stage 64 are inserted. The movable stage 64 is slightly expanded while sliding with respect to the fixed stage 62 under the sliding action between the wedge members 122a and 122b. The convex portion of the first mandrel 114 fixed to the fixed stage 62 side and the convex portion of the second mandrel 120 fixed to the movable stage 64 side are separated from each other by a predetermined distance along the horizontal direction. The portion is substantially crimped to the inner surface of the coupling hole 36.

  In this case, the preliminary load applied to each of the pair of wedge members 122a and 122b is such that the large end portion 38 is not broken even if the convex portion contacts the inner surface of the coupling hole 36 of the large end portion 38, that is, The large end portion 38 is set within an elastically deformable range. As a result, there is no rattling between the large end portion 38 and the convex portions of the first and second mandrels 114, 120, and the connecting rod 30 that is the workpiece is connected to the first and second mandrels 114, It is reliably held by 120 convex portions.

  In this manner, in the state in which the preload is applied to the coupling hole 36 of the large end portion 38 of the connecting rod 30, the pair of second hydraulic cylinders 146a and 146b are driven to support the fourth workpiece made of a block body. The members 134a and 134b are displaced vertically downward. In this case, the convex portion 148 formed on the pair of third support plates 142d and 142e of the support portion 142 and the side surfaces of the fourth work support members 134a and 134b facing the third support plates 142d and 142e are formed. By engaging with the recessed portion 150, a guide action for the vertically downward direction is performed (see FIG. 3).

  As the fourth work support members 134a and 134b are lowered, the pressing surfaces 136 of the fourth work support members 134a and 134b and the inclined surfaces 138 formed at the ends of the third work support members 130a and 130b are mutually connected. And the pair of third work support members 130a and 130b are pressed toward the cap portion 32 side of the connecting rod 30 (step S7).

  As a result, the cap portion 32 of the connecting rod 30 supports a pair of third portions that support both shoulder portions of the cap portion 32 under the pressing action of the pair of fourth work support members 134a and 134b in the vertical downward direction. The workpiece support members 130a and 130b and the flange 120a of the second mandrel 120 between the shoulder portions of the cap portion 32 are completely fixed.

  In this state where the cap portion 32 of the connecting rod 30 is firmly locked, the piston rods 53a and 53b are further moved downward by gradually increasing the driving force of the hydraulic cylinders 55a and 55b of the load mechanism 58, A breaking load is applied to the wedge members 122a and 122b through the piston rods 53a and 53b (step S8).

  Then, a pair of wedge members 122a and 122b is press-fitted between the fixed stage 62 and the movable stage 64, and the tapered wall surfaces of the long grooves 117a and 117b of the fixed stage 62 and the tapered surfaces of the wedge members 122a and 122b. It is further expanded while sliding under the sliding action. A force for moving the movable stage 64 away from the fixed stage 62 is transmitted to the first mandrel 114 on the fixed stage 62 side and the second mandrel 120 on the movable stage 64 side.

  Therefore, when the first mandrel 114 on the fixed stage 62 side and the second mandrel 120 on the movable stage 64 side are separated along the substantially horizontal direction, the large end portion 38 exceeds its elastically deformable limit, Breaking and dividing into the cap part 32 and the rod part 34 with the divided part 44 where the stress is concentrated as a boundary (see FIGS. 10 and 11) (step S9). At this time, since the cap portion 32 is held by the protrusions 132 of the third work support members 130a and 130b under the urging action of the second hydraulic cylinders 146a and 146b, the cap portion 32 that has been divided by breaking is scattered. Definitely blocked.

  That is, in a state where the first mandrel 114 provided on the fixed stage 62 side is fixed, a predetermined breaking load is applied to the pair of wedge members 122a and 122b interposed between the fixed stage 62 and the movable stage 64. By being applied, the second mandrel 120 provided on the movable stage 64 side slides on the moving portion 60b of the base 60 integrally with the slide block 118 under the guide action of the first guide elements 116a and 116b. Displace.

  Therefore, in the state where the rod portion 34 of the connecting rod 30 is fixed to the fixed stage 62 side by the first mandrel 114, the positioning fixing pin 110, and the first workpiece support member 78, the cap portion 32 is a set of fourth workpiece support members. The second mandrel 120 and the slide block 118 on the movable stage 64 side are separated from the fixed stage 62 while maintaining a state of being firmly locked by the 134a and 134b, the third work support members 130a and 130b, and the second mandrel 120. By sliding and displacing on the moving part 60b of the base 60 in the direction, the connecting rod 30 is broken and divided into a cap part 32 and a rod part 34.

  After the large end portion 38 of the connecting rod 30 is broken and divided into the cap portion 32 and the rod portion 34, the hydraulic cylinders 55a and 55b of the load mechanism 58 are driven to raise the wedge members 122a and 122b to return to the initial position. Let

  In this state, the upper ends of the wedge members 122a and 122b are exposed by a predetermined length from the upper surface between the cap portion 32 and the rod portion 34 which are divided by breaking, and the piston rods 152a, 153a and 155a are connected via the connecting plate 124. The fourth air cylinder 152 and the pair of backup cylinders 153 and 155, each of which is fixed to the movable stage 64, are driven substantially simultaneously, and the piston rods 152a, 153a and 155a are respectively extended to move the movable stage 64. By displacing toward the fixed stage 62 side, the fracture surface of the cap portion 32 of the large end portion 38 and the fracture surface of the rod portion 34 are brought into contact with each other.

  Then, in a state where the cap part 32 and the rod part 34 which are divided by breaking are in contact, the hydraulic pressure of the pressure oil supplied to the first hydraulic cylinder 72 is switched from a low pressure to a high pressure under the switching action of a switching valve (not shown). As a result, the force (thrust) that presses the small end portion 40 of the connecting rod 30 toward the large end portion 38 along the axial direction is increased, and at the same time, a second set of second under the switching action of a switching valve (not shown). By switching the pressure of the pressure oil supplied to the hydraulic cylinders 146a and 146b from low pressure to high pressure, a force (thrust force) that presses the pair of third work support members 130a and 130b toward the cap portion 32 side of the connecting rod 30. ). As a result, as shown in FIG. 15, the fracture surface of the cap portion 32 of the large end portion 38 and the fracture surface of the rod portion 34 can be brought into contact with each other with a predetermined thrust applied (step S10). . In other words, by bringing the fracture surface of the cap portion 32 of the large end portion 38 into contact with the fracture surface of the rod portion 34, the thrust (pressing force) applied to the fracture mating surface is simultaneously switched from low pressure to high pressure. The removal or detachment of the fragments generated on the fractured mating surfaces can be facilitated.

  In this case, for example, as shown in FIGS. 16A to 16C, when the cap portion 32 and the rod portion 34 are broken, the main crack 200 propagates to cause brittle fracture, and the main crack 200 is being propagated. There is a possibility that a fine sub-crack 202 may be generated due to the main crack 200 branching. When the connecting rod 30 is assembled to the internal combustion engine or when the internal combustion engine is driven, the sub-crack 202 grows or the sub-cracks 202 propagate to each other so that the fracture surface of the cap portion 32 and the fracture surface of the rod portion 34 are transmitted. A portion 204 where the contact point on the mating surface substantially disappears (see FIG. 16B). Such a part 204 is fragile, and when a load (stress) is applied to the part 204 for some reason, there is a concern that the part 204 may be lost and become a fragment as shown in FIG. 16C. .

  Therefore, in the present embodiment, immediately after the connecting rod 30 is split into the cap portion 32 and the rod portion 34 by the lowering action of the wedge members 122a and 122b, the fourth air cylinder 152, the pair of backup cylinders 153, 153 is driven substantially simultaneously to displace the movable stage 64 toward the fixed stage 62 side, and the fracture surface of the cap portion 32 of the large end portion 38 and the fracture surface of the rod portion 34 are brought into contact with each other. By applying a predetermined thrust to the surfaces, the pieces generated on the fractured mating surfaces can be separated or the separation of the pieces can be favorably promoted.

  As described above, in the present embodiment, the movable portion 64 and the rod portion 34 are held by the movable stage 64 and the fixed stage 62, respectively, immediately after the fracture and division into the cap portion 32 and the rod portion 34. When the stage 64 is moved to the fixed stage 62 side, the fracture surface of the cap portion 32 is brought into contact with the fracture surface of the rod portion 34, and the fracture-matching surface is further pressed, whereby a piece is generated on the fracture-matching surface. Even if it exists, the said piece can be removed or detachment | leave of the said piece can be accelerated | stimulated suitably.

  That is, after the removal or detachment of the piece in which the fracture surface of the cap portion 32 and the fracture surface of the rod portion 34 which are divided by breaking is promoted, a predetermined thrust is applied to the cap portion 32 and the rod portion 34. The first hydraulic cylinder 72 and the pair of second hydraulic cylinders 146a and 146b that have been applied are deenergized to cancel the application of thrust to the fracture mating surface of the connecting rod. As a result, the fracture joining surfaces of the cap part 32 and the rod part 34 are slightly separated, and the pieces generated on the fracture joining surface are smoothly separated.

  Next, an oil hole forming step of forming the oil hole 41 with respect to the rod part 34 by operating the oil hole machining mechanism 59 in a state where the cap part 32 and the rod part 34 of the connecting rod 30 are firmly locked. Execute (Step S11). Here, the operation and effect of the oil hole forming step will be described in detail based on the flowchart shown in FIG. In this case, it is sufficient that at least the rod portion 34 is firmly locked, and the cap portion 32 side is not necessarily locked firmly.

  First, in the state where the rod portion 34 is firmly locked as described above, the moving mechanism portion 83 of the oil hole machining mechanism 59 is operated. That is, the ball screw 91 is rotationally driven by the motor 89 being rotationally driven. Then, as shown in FIG. 12, the moving part 60b of the base 60 to which the cap part 32 is fixed moves the base 60 through the nut member 93 under the guiding action of the guide bars 95a and 95b. It slides on the second support portion 69b of the base support body 69 in the axial direction, and is stopped after being separated (slid) by a predetermined distance from the rotating portion 60a (step S101).

  In this case, the moving distance of the moving part 60b needs to be larger than at least the distance that the two parts do not interfere when the rotating part 60a rotates. It is better to be separated by a sufficient distance that does not become necessary.

  Subsequently, the rotation mechanism unit 85 rotates the rotation part 60 a of the base 60 so as to slide on the first support part 69 a of the base support 69. That is, as shown in FIGS. 4 and 12, when the motor 97 is rotationally driven and the rotational driving force is transmitted from the gear body 99 to the rotary shaft 81 via the gear body 101, the guide groove 69e and the guide pin Under the guiding action with 87 (see FIG. 9), the rotating portion 60a of the base 60 is stopped in a state where it is rotated by a predetermined angle in the horizontal direction around the rotating shaft 81 on the first support portion 69a. (Step S102). Here, as described above, since the load mechanism 58 is fixed to the rotating portion 60a by the third brackets 61a and 61b via the storage boxes 57a and 57b, the load mechanism 58 is also integrated with the rotating portion 60a. It will be rotated.

  In this case, the rotation angle of the rotation part 60a is appropriately set, for example, between 10 ° and 90 ° to such an extent that the processing operation of the oil hole 41 by the next tool 103 can be easily performed. In addition, the rotation direction of the rotation unit 60 a is a direction suitable for machining work by the tool 103.

  As described above, the broken and divided rod portion 34 rotates while being firmly locked to the first mandrel 114 by the positioning fixing pin 110, the first work support member 78, and the second work support member 104. The guide hole 105 provided in the first mandrel 114 is set so as to be directed to the outside of the division processing apparatus 50 by being rotated by a predetermined angle by the portion 60a (see FIGS. 12 and 17). That is, the rod portion 34 is rotated to an angle at which the tool 103 can be easily inserted into the guide hole 105.

  Subsequently, as shown in FIG. 17, the drill portion 103 a at the tip of the tool 103 is inserted through the guide hole 105 provided in the first mandrel 114, and the outer diameter side from the inner diameter side of the coupling hole 36 of the rod portion 34. And the oil hole 41 is formed (step S103).

  Therefore, in the present embodiment, the oil hole 41 can be processed in a state where the rod portion 34 is securely fixed to the first mandrel 114 while being broken and divided. At this time, the tool 103 can drill the oil hole 41 in the rod portion 34 while being guided by the guide hole 105.

  From the above, in the present embodiment, the workpiece positioning and holding mechanism 52 including the first mandrel 114 can be used as a positioning jig for processing the oil hole 41 in the rod portion 34. That is, as described above, even when the rod portion 34 contracts or expands due to the residual stress generated after the fracture of the connecting rod 30, the rod portion 34 is securely fixed to the first mandrel 114. The process can proceed to the oil hole forming process. For this reason, when processing the oil hole 41, it is not necessary to prepare a jig for each individual connecting rod 30, and it is not necessary to adjust each individual according to the contraction, that is, the first mandrel. 114 can be used as a common jig for use in oil hole machining of each connecting rod manufactured by the split machining apparatus 50.

  In this case, since the oil hole 41 is processed from the inner diameter side to the outer diameter side of the coupling hole 36 of the rod portion 34 using the first mandrel 114 as a jig, the coupling hole 36 in which a crank pin (not shown) slides after the processing. No burrs are generated on the inner wall of the wall.

  Further, since the outer wall portion on the outer diameter side of the coupling hole 36 is a slightly curved forged skin, when the oil hole 41 is processed from the outer wall portion toward the inner wall portion, the drilled portion 103a is formed by the forged skin. There is a concern that the blade edge may be blurred. However, in the present embodiment, as described above, since the machining is performed from the inner diameter side to the outer diameter side and the drill portion 103a is guided by the guide hole 105, the drill portion 103a as described above in the drilling direction. Shaking can be prevented and processing can be performed with high accuracy.

  As described above, according to this embodiment, the oil hole machining mechanism 59 as described above is provided, and the first mandrel 114 is used as a jig, so that the contraction due to the residual stress generated after the fracture splitting as in the connecting rod 30. Even in the case of a so-called fracture-dividing connecting rod that may cause expansion, the oil hole 41 can be formed with high accuracy in the rod portion 34. Further, after the fracture division, the oil hole 41 can be continuously processed while the rod portion 34 is fixed. For this reason, it is not necessary to release the fixing of the rod portion 34 with the processing of the oil hole 41, transfer it to a jig of another apparatus and fix it again, and then process the oil hole, thereby simplifying the manufacturing process. It is possible to improve production efficiency by making it easier. Furthermore, since it is not necessary to transfer or re-fix to the separate device, it is possible to avoid the inconvenience of accidentally destroying the fracture surface of the rod portion 34 during the movement or the like.

  When the processing of the oil hole 41 is completed in this way, the motor 97 of the rotation mechanism unit 85 and the motor 89 of the movement mechanism unit 83 are then driven to turn the rotation unit 60a and the movement unit of the base 60, respectively. 60b is returned to the initial position (step S104). Thereby, the oil hole formation process to the rod part 34 is complete | finished.

  In addition, the connecting rod 30 in which the detachment of the fragments is promoted can be reliably removed from the fractured surface by, for example, a metal brush, an adhesive tape, a suction machine, or a vibrator in the next step. That is, when using a metal brush, brushing is performed on the fracture surface. Moreover, when using an adhesive tape, after pressing and adhering an adhesive tape to a torn surface, a piece can be made to adhere to an adhesive tape by peeling the said adhesive tape from a torn surface. And when using a suction device, a piece can be made to peel from a torn surface under a suction action of a suction device. Thus, in any case, the fragments can be reliably removed from the fracture surface.

  Then, the first hydraulic cylinder 72, the second hydraulic cylinders 146a, 146b, the second air cylinder 94, the third air cylinders 126a, 126b, the fourth air cylinder 152, and the backup cylinders 153, 155 are driven, respectively. The first to fourth work support members 78, 104, 130a, 130b, 134a, 134b return to the initial positions substantially simultaneously (step S12).

  After the members that constrain the cap portion 32 and the rod portion 34 of the connecting rod 30 that are broken and divided in this way and in which the oil holes 41 are formed are returned to their initial positions and the connecting rod 30 is opened, they are not shown. The cap part 32 and the rod part 34 are respectively held by a pair of chuck mechanisms mounted on the arm of the multi-axis robot, and the cap part 32 and the rod part 34 are transferred to the next process. Finally, the fifth air cylinder 154 is driven to displace the entire movable stage 64, and the movable stage 64 returns to the initial position.

  By the way, in the present embodiment, in the oil hole machining mechanism 59, the moving part 60b is moved forward and backward, and the rotating part 60a is rotated. However, the present invention is not limited to this. 18 may be configured as shown in a split machining apparatus 51 according to another embodiment of FIG.

  That is, in the division processing apparatus 51, a moving mechanism portion (not shown) similar to the moving mechanism portion 83 is installed with the rotating portion 60a as the displacement portion 60c, and the displacement portion 60c is moved in the advancing / retreating direction of the moving portion 60b (the arrow in FIG. 18). It can be displaced in a direction (arrow Y direction in FIG. 18) perpendicular to the X direction. Thereby, the tool 103 can be inserted into the guide hole 105 of the first mandrel 114, and the oil hole 41 can be formed with high accuracy.

  As described above, the oil hole machining mechanism (lubricant supply hole machining mechanism) may be configured so that the tool 103 can be effectively brought into contact with the rod portion 34 fixed to the first mandrel 114. . Accordingly, the rotating portion 60a (displacement portion 60c) is fixed, and the moving portion 60b is configured to be movable back and forth and rotated (displaced), or the moving portion 60b is fixed and the rotating portion 60a (displacement) is configured. The part 60c) may be configured to be capable of moving forward and backward and turning (displacement).

  Next, a description will be given of the case where the large end portions of various connecting rods having different inner diameters are broken and divided to form oil holes (lubricating oil supply holes).

  In this case, as shown in FIG. 7, the first mandrel 114 connected to the first connection block 107a on the fixed stage 62 side is removed from the recess 109a by loosening the mounting screw 111 and the second on the movable stage 64 side. The second mandrel 120 connected to the connection block 107b is removed from the recess 109b. Then, other not-shown first mandrels 114 and second mandrels 120 having projections having outer diameters corresponding to the inner diameters of the coupling holes at the large ends of the other connecting rods not shown are respectively attached via mounting screws 111. It fixes to the 1st connection block 107a and the 2nd connection block 107b.

  As described above, in the present embodiment, the pair of wedge members 122a and 122b is not replaced, and the first mandrel 114 and the second mandrel 120 (not shown) having a desired outer diameter are replaced with each other. The work efficiency and versatility in dividing and oil hole formation can be improved.

1A is a perspective view of a connecting rod to which the present invention is applied, FIG. 1B is a perspective view showing a state in which the connecting rod is divided into a cap portion and a rod portion, and FIG. 1C is a perspective view of FIG. It is the perspective view which reversed the top and bottom of the connecting rod shown in FIG. It is a partial exploded perspective view of the division | segmentation processing apparatus which concerns on embodiment of this invention. It is a partial cross section top view of the division | segmentation processing apparatus shown in FIG. It is a partial longitudinal cross-sectional view along the axial direction of the division | segmentation processing apparatus shown in FIG. It is a partial cross-section enlarged perspective view of the division processing apparatus shown in FIG. It is a partial expanded longitudinal cross-sectional view of the division | segmentation processing apparatus shown in FIG. It is a partially broken perspective view which shows the state in which a pair of mandrel was provided detachably through the attachment screw. It is a partially broken exploded perspective view which shows one mandrel provided with the guide hole among the mandrels shown in FIG. It is sectional drawing in line IX-IX in FIG. It is a partial expansion perspective view which shows the state by which the connecting rod was fractured | ruptured into the cap part and the rod part. It is a partial expansion perspective view which shows the state by which the connecting rod was fractured | ruptured into the cap part and the rod part. It is a partially broken top view which shows the state which moved the moving part of the division | segmentation processing apparatus shown in FIG. 2, and rotated the rotation part. It is a flowchart which shows the procedure of the manufacturing method of the connecting rod which concerns on this Embodiment. It is a flowchart which shows the procedure of an oil hole formation process. It is a partial expansion perspective view which shows the state which the fracture surface of the cap part and the fracture surface of the rod part which were fracture-divided contact | abutted and pressed. FIG. 16A to FIG. 16C are main part enlarged front views respectively showing a process until a crack develops from a fractured surface to generate a sub-crack, and further, the sub-cracks propagate to each other and are lost as a piece. It is a partially broken top view which shows the state which is processing the oil hole in the rod part of a connecting rod using the division | segmentation processing apparatus shown in FIG. It is a partially broken top view which shows the state which moved the moving part and displaced the displacement part in the division | segmentation processing apparatus which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 30 ... Connecting rod 32 ... Cap part 34 ... Rod part 38 ... Large end part 40 ... Small end part 41 ... Oil hole 50, 51 ... Dividing machine 52 ... Work positioning holding mechanism 54 ... Breaking division mechanism 58 ... Load mechanism 59 ... Oil hole machining mechanism 60 ... base 60a ... rotating part 60b ... moving part 60c ... displacement part 62 ... fixed stage 64 ... movable stage 69 ... base support 69e ... guide groove 81 ... rotating shafts 82a, 82b, 95a, 95b ... guide bar 83 ... moving mechanism 85 ... rotating mechanism 87 ... guide pins 89, 97 ... motor 91 ... ball screw 93 ... nut member 99, 101 ... gear body 103 ... tool 103a ... drill part 105 ... guide hole 114, 120 ... Mandrels 122a, 122b ... Wedge members

Claims (4)

After integrally forming a connecting rod having a large end and a small end, the coupling hole of the large end is set in a set of expansion tools, and the expansion tool is expanded to cap the large ends. A connecting rod for breaking and dividing into a main part and a lubricating oil supply hole penetrating the large end part in the main part,
The main body portion side is fixed by the one extension tool and the first stage, and the cap portion side is fixed by the other extension tool and the second stage, and is split into a cap portion and a main body portion. rear,
The manufacturing method of a connecting rod, wherein the lubricating oil supply hole is formed by separating the main body portion and the cap portion by a predetermined distance while at least the main body portion side is fixed. In the manufacturing method of the connecting rod of Claim 1,
A method of manufacturing a connecting rod, wherein a tool is guided through a guide portion provided on the one extension tool for fixing the main body portion to form the lubricating oil supply hole. After integrally forming a connecting rod having a large end and a small end, the coupling hole of the large end is set in a set of expansion tools, and the expansion tool is expanded to cap the large ends. A connecting rod manufacturing apparatus for breaking and dividing into a body part and a body part,
A fixed stage fixed on the base;
A movable stage disposed opposite to the fixed stage and provided so as to approach or separate from the fixed stage along a horizontal direction;
One extension tool on the main body part side detachably provided on the fixed stage, and the other extension tool on the cap part side detachably provided on the movable stage;
A wedge member provided between the fixed stage and the movable stage and press-fitted to separate the movable stage from the fixed stage;
A load mechanism for applying a rupture load in the press-fitting direction of the wedge member in order to break and divide the large end portion;
At least one of the fixed stage or the movable stage is moved in a direction away from the other, and at least one of the fixed stage or the movable stage is displaced or rotated in a direction crossing the direction of separation. A lubricating oil supply hole machining mechanism;
An apparatus for manufacturing a connecting rod, comprising: The connecting rod manufacturing apparatus according to claim 3,
One connecting tool on the main body side is provided with a guide portion for guiding a tool for forming a lubricating oil supply hole penetrating the large end portion in the main body portion. Manufacturing equipment.

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