WO2015016074A1 - Assembled camshaft - Google Patents
Assembled camshaft Download PDFInfo
- Publication number
- WO2015016074A1 WO2015016074A1 PCT/JP2014/068988 JP2014068988W WO2015016074A1 WO 2015016074 A1 WO2015016074 A1 WO 2015016074A1 JP 2014068988 W JP2014068988 W JP 2014068988W WO 2015016074 A1 WO2015016074 A1 WO 2015016074A1
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- WO
- WIPO (PCT)
- Prior art keywords
- shaft member
- lobe
- cam
- key
- peripheral surface
- Prior art date
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/02—Valve drive
- F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/02—Valve drive
- F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
- F01L1/08—Shape of cams
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H53/00—Cams ; Non-rotary cams; or cam-followers, e.g. rollers for gearing mechanisms
- F16H53/02—Single-track cams for single-revolution cycles; Camshafts with such cams
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/02—Valve drive
- F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
- F01L1/047—Camshafts
- F01L2001/0475—Hollow camshafts
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L2305/00—Valve arrangements comprising rollers
Definitions
- the present invention relates to an assembly camshaft that rotates in conjunction with a crankshaft of an internal combustion engine.
- An assembly camshaft is a hollow shaft member that is assembled by combining a plurality of cam lobes (cams) at a predetermined position at a predetermined phase by a method such as shrink fitting or caulking. Part of the valve mechanism of the engine).
- Patent Document 1 discloses an assembly in which a predetermined number of cam lobes are inserted and positioned in a shaft member, and a mandrel is inserted into the shaft member to expand the shaft member and crimp, thereby fastening the cam lobe to the shaft member.
- a camshaft is described.
- the cam lobe when the cam lobe is fixed to the shaft member by shrink fitting, the larger the tightening allowance, the greater the tightening force of the cam lobe against the shaft member. Is done.
- a cam lobe with a roller if it is heated to a temperature higher than the tempering temperature of the roller, the roller is annealed and the hardness of the roller is lowered. It is.
- the present invention is not limited to this purpose, and is a function and effect derived from each configuration shown in the embodiments for carrying out the invention described later, and other effects of the present invention are to obtain a function and effect that cannot be obtained by conventional techniques. Can be positioned.
- An assembly camshaft disclosed herein includes a shaft member that rotates in conjunction with a crankshaft of an internal combustion engine, a pair of cam lobes that drive a pair of intake valves or a pair of exhaust valves used in the same cylinder of the internal combustion engine, and An assembly camshaft comprising a coupling cam lobe having a mounting hole through which the shaft member is inserted, wherein a journal portion provided between the pair of cam lobes is integrally formed, and each of the pair of cam lobes includes a base circular portion and A cam lobe with a roller having a base cam formed of a valve lift portion and a roller provided at a tip portion of the valve lift portion and rotatable with respect to the base cam, and an outer peripheral surface of the shaft member and an inner peripheral surface of the mounting hole A key extending in the axial direction of the shaft member is fitted at least in the journal portion. Murrell.
- the shaft member is pivotally supported by being sandwiched between a bearing portion and a cam cap provided at an upper portion of the cylinder head in the journal portion.
- the coupling cam lobe is assembled by being externally fitted to the shaft member, and has a key groove (lobe side key groove) provided in the base circle portion and formed along the axial direction on the inner peripheral surface of the mounting hole. Is preferred. It is preferable that the key protrudes outwardly on the outer peripheral surface of the shaft member and is fitted into the key groove at least in the journal portion.
- the key is provided between the outer peripheral surface of the shaft member and the inner peripheral surface of the mounting hole at a position facing the roller across the axis of the shaft member.
- the key groove is preferably formed on a surface opposite to the valve lift portion of the inner peripheral surface of the mounting hole, and on a straight line connecting the shaft center of the mounting hole and the shaft center of the roller. It is more preferable that the valve lift part is recessed in a straight line along the axial direction on the surface far from the tip part.
- the shaft member has a shaft-side key groove formed along the axial direction of the shaft member, and the coupling cam lobe is formed on the inner peripheral surface of the mounting hole over the entire axial length of the coupling cam lobe. It is preferable to have a lobed side keyway. In this case, it is preferable that the key is fitted into the shaft side keyway and the lobe side keyway. It is preferable that the depth of the lobe-side key groove is set to be larger than an amount protruding from the outer peripheral surface of the shaft member in a state where the key is fitted into the shaft member.
- the coupling cam lobe preferably has a lobe-side key groove formed along the axial direction of the coupling cam lobe on the inner peripheral surface of the mounting hole. In this case, it is preferable that the key is integrally formed with the shaft member and fitted into the lobe-side key groove.
- the pair of cam lobes are cam lobes with rollers, friction can be reduced compared to cam lobes without rollers, and fuel efficiency can be improved. Furthermore, since the roller itself rotates on the tappet, the cam driving torque in the low rotation range can be reduced.
- FIG. 6 is a cross-sectional view (a cross-sectional view taken along the line AA in FIG. 2) in a direction orthogonal to the axial direction of the coupling cam lobe of the assembly cam shaft according to the embodiment.
- FIG. 6 is a cross-sectional view (a cross-sectional view taken along the line BB in FIG. 2) in a direction orthogonal to the axial direction of the journal portion of the assembly cam shaft according to the embodiment.
- FIG. 1 is a perspective view of one end side of the assembly camshaft 10
- FIG. 2 is a longitudinal sectional view along the axial direction of the assembly camshaft 10 shown in FIG. Indicates the state that has been performed.
- 3 is a cross-sectional view taken along the line AA in FIG. 2
- FIG. 4 is a cross-sectional view taken along the line BB in FIG.
- the assembly camshaft 10 is a hollow pipe-shaped shaft member 20 that is integrally assembled with a plurality of coupling cam lobes 30 that are externally fitted, and is an engine (not shown). Part of the valve mechanism. Although only one coupling cam lobe 30 is illustrated in FIG. 1, a plurality of coupling cam lobes 30 are provided in the axial direction of the shaft member 20 according to the number of cylinders.
- the shaft member 20 is pivotally supported by an upper end edge (not shown) of an end wall portion in which one end portion 20a and the other end portion (not shown) are erected at both axial ends of the crankshaft of the cylinder head.
- a cam sprocket (not shown) is coupled to one end 20 a of the shaft member 20.
- the rotation of the crankshaft is transmitted to the shaft member 20 via a timing chain and a timing belt (both not shown) spanned between a crank sprocket coupled to one end of the crankshaft of the engine and a cam sprocket.
- Engine oil lubricating oil
- an oil pump (not shown) flows through the hollow interior of the shaft member 20.
- the combined cam lobe 30 is formed by integrally forming a pair of cam lobes 30A and 30A and a cylindrical journal portion 30B provided between the pair of cam lobes 30A and 30A.
- integral molding as used herein means making a shape as an integral one. That is, the combined cam lobe 30 is not formed by combining two cam lobes of the same shape that are separately formed via the journal part, but has a shape having a pair of cam lobes 30A, 30A and a journal part 30B from the beginning. Molded.
- the pair of cam lobes 30A, 30A drives a pair of intake valves or a pair of exhaust valves (hereinafter also simply referred to as valves) used in the same cylinder of the engine.
- the pair of cam lobes 30A and 30A have the same shape and are formed so that the phase difference is zero or substantially zero.
- the coupling cam lobe 30 is sandwiched between a bearing portion 40 and a cam cap 41 provided at an upper portion of the cylinder head at a substantially axial center of the journal portion 30 ⁇ / b> B.
- the assembly camshaft 10 is pivotally supported by the bearing portion 40 and the cam cap 41.
- the cam cap 41 is fastened by a bolt 42 with the assembly cam shaft 10 sandwiched between the upper surface of the bearing portion 40.
- a small gap (not shown) is provided on the sliding surface between the cam cap 41 and the bearing portion 40 and the assembly camshaft 10, and engine oil for lubrication is supplied to the gap from an oil supply passage (not shown). Is done.
- the cam lobe 30 ⁇ / b> A is a cam lobe with a roller including a plate-shaped base cam 31 that is a cam body and a cylindrical roller 32 attached to the base cam 31.
- the cam lobe 30A drives a tappet (a driven part, also called a valve lifter, not shown) connected to the base end of the valve in each cylinder of the engine to open and close the valve.
- the base cam 31 has a base circle portion 31a and a valve lift portion 31b, and the outer peripheral surface (cam surface) is continuous over the entire circumferential direction.
- a boundary line between the base circle portion 31a and the valve lift portion 31b is indicated by a two-dot chain line in FIG.
- the base circular portion 31a is a circular portion of the base cam 31, and a circular hole portion 31h (hereinafter referred to as a cam shaft hole portion 31h) through which the shaft member 20 is inserted is drilled in the center.
- the base circle portion 31a corresponds to a portion where the distance from the axis S of the camshaft hole portion 31h is constant.
- the valve lift part 31b is a part formed by partially bulging the outer edge of the base circle part 31a in the diameter increasing direction, and is a part that opens and closes the valve by pressing the top surface of the tappet.
- the valve lift portion 31b is formed at the intermediate portion in the width direction of the base cam 31 (the direction in which the shaft member 20 is inserted, the plate thickness direction), and the outer peripheral surface from the tip portion (cam top) 31c toward the base circle portion 31a. It has a notch 31n formed by notching. A roller 32 described later is provided in the notch 31n so as to be rotatable with respect to the base cam 31.
- a pair of opposing yoke portions 31y and 31y are formed on both sides in the width direction of the notch portion 31n formed in the base cam 31.
- holes 31m, 31m penetrating in the width direction are provided on a straight line.
- the hole 31m is formed such that its axis T is parallel to the axis S of the camshaft hole 31h formed in the base circle 31a.
- a roller shaft 33 for attaching the roller 32 to the base cam 31 is inserted through the holes 31m and 31m.
- the hole 31m is referred to as a roller shaft hole 31m.
- a claw portion (not shown) projecting to the outer diameter side is provided on the peripheral edge of the roller shaft 33, and this claw portion is struck against the end surface of the yoke portion 31y of the base cam 31 to be caulked.
- a roller shaft 33 is fixed to 31.
- the roller 32 is rotatably assembled to the base cam 31 via a roller shaft 33 inserted through the center thereof.
- the inner peripheral surface 32 h of the roller 32 functions as a sliding bearing for the roller shaft 33.
- the roller 32 is attached such that a part of its outer peripheral surface protrudes outside the outer peripheral surface of the tip end portion 31c of the valve lift portion 31b. The amount of protrusion of the roller 32 from the tip portion 31 c is determined by the shape of the base cam 31 and the outer diameter of the roller 32.
- valve lift 31b of the base cam 31 comes into contact with the tappet and presses the tappet.
- the valve lift 31b pushes down the tappet as the assembly camshaft 10 rotates.
- the position of contact with the tappet moves from the valve lift 31b to the roller 32, and this time the roller 32 presses the tappet.
- the roller 32 moves while rolling on the tappet to push down the tappet, and finally the valve lift amount is maximized.
- the valve lift amount decreases, the contact position with the tappet changes from the roller 32 to the valve lift portion 31b, and the valve lift portion 31b presses the tappet again.
- the valve lift part 31b moves away from the tappet and the base circle part 31a faces the tappet, the valve lift amount becomes zero.
- the cam lobe 30A with a roller can reduce friction compared to a cam lobe without the roller 32 because the roller 32 moves while rolling on the tappet and presses the tappet. Further, since the roller 32 itself rotates on the tappet, an excellent effect can be obtained, such as reduction of cam driving torque in a low rotation range.
- the pair of cam lobes 30A and 30A of the combined cam lobe 30 have the same shape as described above and have a phase difference of zero or substantially zero. That is, the base cams 31 and 31 of the pair of cam lobes 30A and 30A are provided with valve lift portions 31b and 31b at the same position (angle) in the circumferential direction so that the same rollers 32 and 32 have the same protruding amount. 31 and 31. Therefore, the variation between a pair of intake valves or a pair of exhaust valves used in the same cylinder is minimized.
- the journal portion 30B is a cylindrical portion formed integrally with the pair of cam lobes 30A and 30A so as to connect the opposing end surfaces of the base circular portions 31a of the pair of cam lobes 30A and 30A. It is.
- the journal portion 30B is a portion that is supported by the bearing portion 40 and the cam cap 41 as described above.
- the coupling cam lobe 30 has a mounting hole 30h (that is, the cam shaft hole portions 31h and 31h and the inner peripheral surface of the journal portion 30B) through which the shaft member 20 is inserted.
- the diameter (inner diameter) of the mounting hole 30 h is smaller than the outer diameter of the shaft member 20. That is, a fastening margin is provided between the coupling cam lobe 30 and the shaft member 20, and the coupling cam lobe 30 is fitted into the shaft member 20 by shrink fitting.
- the coupling cam lobe 30 is heated to a predetermined temperature at the time of assembly, and the attachment hole 30h expands and is fitted onto the shaft member 20 when it is wider than the outer diameter of the shaft member 20.
- the predetermined temperature at this time is set to a temperature lower than a tempering temperature of a roller 32 which will be described later, thereby preventing the roller 32 from being annealed during assembly.
- the tightening allowance is set to such a size that the coupling cam lobe 30 can be assembled to the shaft member 20 even when the temperature during shrink fitting is set to a temperature lower than the tempering temperature of the roller 32.
- a key 34 extending in the axial direction is fitted between the coupling cam lobe 30 and the shaft member 20.
- the key 34 is a member for transmitting the rotational motion and rotational torque of the shaft member 20 to the coupling cam lobe 30 and bearing the rotational torque of the coupling cam lobe 30 and is formed in an elongated rectangular parallelepiped shape.
- the key 34 is formed to have the same length as the axial length of the coupling cam lobe 30.
- the coupling cam lobe 30 can be connected to the shaft even if the tightening force of the coupling cam lobe 30 on the shaft member 20 is not increased so much.
- the member 20 is not shifted in the circumferential direction. For this reason, it is possible to set a small fastening margin when the coupling cam lobe 30 is fixed to the shaft member 20 by shrink fitting. In other words, the coupling cam lobe 30 can be reliably fixed to the shaft member 20 by providing the key 34 even with a small allowance.
- a key groove 20k into which the key 34 is press-fitted (hereinafter referred to as a shaft-side key groove 20k) is formed on the outer peripheral surface of the shaft member 20.
- the shaft-side keyway 20k is located in the axial direction of the shaft member 20 at a position (a position shifted by 180 degrees) on the opposite side of the outer peripheral surface of the shaft member 20 from the surface located on the cam top 31c side of the coupling cam lobe 30. It is recessed along a straight line.
- the shaft side keyway 20 k is formed in a shape corresponding to the shape of the key 34. For example, it is formed to have a length and width equivalent to the length and width of the key 34, and is formed to a depth that is approximately half the height of the key 34.
- a key groove 30k (hereinafter referred to as a lobe-side key groove 30k) into which the key 34 is fitted is formed in the mounting hole 30h of the coupling cam lobe 30 on the inner peripheral surface opposite to the valve lift portion 31b.
- the lobe side keyway 30k is a straight line connecting the axis S of the camshaft hole 31h and the axis T of the roller shaft hole 31m on the inner peripheral surface of the mounting hole 30h. On the surface far from the top 31c, it is recessed in a straight line along the axial direction of the coupling cam lobe 30.
- the lobe-side key groove 30k is provided at a position overlapping the shaft-side key groove 20k when the coupling cam lobe 30 is assembled to the shaft member 20.
- the lobe-side keyway 30k extends from the end surface of the one cam lobe 30A opposite to the journal portion 30B to the end surface of the other cam lobe 30A opposite to the journal portion 30B. That is, the lobe-side key groove 30k is formed so as to penetrate the coupling cam lobe 30 in the axial direction (over the entire length in the axial direction). Further, the width of the lobe-side key groove 30k is formed to be equal to the width of the key 34, and the depth of the lobe-side key groove 30k is formed to be equal to or slightly larger than the protruding amount of the key 34 from the outer peripheral surface of the shaft member 20. ing.
- the depth of the lobe-side keyway 30k is set to be larger than the amount protruding from the outer peripheral surface of the shaft member 20 in a state where the key 34 is fitted in the shaft member 20. Accordingly, when the coupling cam lobe 30 is fitted into the shaft member 20, a gap is formed between the key 34 and the lobe-side key groove 30k, so that the deformation of the cam surface of the coupling cam lobe 30 when the key is fitted is avoided.
- the key 34 is press-fitted into the shaft-side keyway 20k and protrudes outward from the outer peripheral surface of the shaft member 20.
- the coupling cam lobe 30 is assembled, the coupling cam lobe 30 is fitted from the axial direction of the shaft member 20 such that the lobe-side key groove 30k is fitted to the protruding key 34.
- the key 34 is fitted into the lobe-side key groove 30 k over the entire axial length of the coupling cam lobe 30.
- the coupling cam lobe 30 is an interference fit with respect to the shaft member 20, while the key 34 is an intermediate fit with respect to the lobe side key groove 30k.
- a protrusion amount setting process, a selection process, and a surface treatment process for the roller 32, and a roughing process, a finishing process, a grinding process, and a surface for the base cams 31, 31 and the journal portion 30B of the pair of cam lobes 30A, 30A are provided. Processing steps. Furthermore, it has an assembling process for assembling the rollers 32, 32 to the base cams 31, 31, respectively, and an assembling process for fitting the coupling cam lobe 30 into the shaft member 20 for assembly.
- each process for the roller 32 will be described.
- the protrusion amount of the roller 32 from the outer peripheral surface of the base cam 31 is set (setting step), and the rollers 32 having the outer diameters corresponding to the protrusion amount are prepared for the number of cam lobes 30A (selection step).
- a surface hardening process is performed on the roller 32 and the roller shaft 33, respectively.
- general induction hardening and tempering are performed as the surface hardening treatment.
- a relatively thick hardened layer is formed on each surface of the roller 32 and the roller shaft 33 (surface treatment process).
- each process for the base cams 31 and 31 and the journal portion 30B of the pair of cam lobes 30A and 30A will be described.
- the parts that form the basis of the base cams 31 and 31 and the journal part 30B are integrally formed by forging.
- the forged product is roughly processed to form a portion that becomes the notch 31n, and a portion that becomes the mounting hole 30h of the shaft member 20 and the roller shaft hole 31m is drilled.
- the outer peripheral surface of this forged product is roughed to form a shape close to the final cam profile of the base cam 31 (roughing process).
- the shape close to the final cam profile here refers to a shape that becomes a desired cam profile only by finishing (that is, grinding) the outer peripheral surface.
- the rough machining step is omitted, and at the stage of forming the forged product, the notch 31n, the mounting hole 30h, and the roller shaft hole 31m are formed, and the outer peripheral surface becomes the final cam profile of the base cam 31. You may form in a near shape.
- the forged product after the roughing process is formed into the final shape of the base cam 31 in the finishing process.
- the finishing process may be performed using a device capable of performing numerical control, such as an NC lathe, or may be performed manually.
- the mounting hole 30h of the shaft member 20 is finished, and then the roller shaft hole 31m is positioned and finished with reference to the mounting hole 30h.
- the mounting hole 30 h is formed to have a diameter slightly smaller than the outer diameter of the shaft member 20, and the roller shaft hole 31 m is formed to have a diameter slightly larger than the diameter of the roller shaft 33. This is because the coupling cam lobe 30 is fixed to the shaft member 20 by shrink fitting while the roller shaft 33 is fixed to the base cam 31 by caulking.
- the forged product in which the mounting hole 30h and the roller shaft hole 31m are formed is then ground on its outer peripheral surface (grinding step).
- the mounting hole 30h and the roller shaft hole 31m are each fixed by a chuck to support the forged product, and forging is performed for a predetermined feed amount (cutting amount) while contacting a grinding wheel rotating at high speed on the outer peripheral surface. Proceed to the product side and grind the outer peripheral surface of the forged product. Thereby, the base cam 31 having a desired cam profile is completed.
- the completed pair of base cams 31 and 31 and the journal portion 30B are subjected to, for example, a general gas nitriding treatment or quenching and tempering treatment in the surface treatment process. Note that the surface treatment of the journal portion 30B may be omitted.
- the rollers 32 are rotatably assembled to the pair of base cams 31, 31 that have undergone the above processes, via the roller shaft 33.
- the roller 32 has a central through hole overlapped with the roller shaft hole portions 31m and 31m formed in the yoke portions 31y and 31y of the base cam 31, and the gap between the two yoke portions 31y and 31y is substantially omitted. It arrange
- the roller shaft 33 is inserted into the roller shaft hole 31m of the one yoke portion 31y, subsequently inserted into the through hole of the roller 32, and further into the roller shaft hole 31m of the other yoke portion 31y. It is inserted. And it fixes to the base cam 31 by expanding the both ends of the roller shaft 33 by caulking.
- the combined cam lobe 30 is manufactured by attaching the rollers 32 and 32 to the base cams 31 and 31 of the pair of cam lobes 30A and 30A, respectively. Any of the steps for the roller 32 and the steps for the base cams 31 and 31 and the journal portion 30B may be performed first or simultaneously.
- the key 34 is first press-fitted into the shaft-side keyway 20k of the shaft member 20. Then, the coupling cam lobe 30 heated to a predetermined temperature is inserted into the shaft member 20 from the axial direction so that the lobe-side key groove 30k is fitted to the key 34 protruding from the outer peripheral surface of the shaft member 20.
- the temperature of the coupling cam lobe 30 is lowered, the assembly camshaft 10 in which the coupling cam lobe 30 is firmly fixed to the shaft member 20 is completed.
- the variation in the same cylinder can be minimized by integrally forming the coupling cam lobe 30 and the coupling cam lobe 30 is assembled using the key 34. Can be secured. Thereby, since the finishing process after an assembly process can be omitted, the manufacturing cost can be reduced. In addition, since variations within the same cylinder can be minimized, the accuracy of engine control can be increased, and as a result, output and exhaust performance can be improved.
- the rotational torque of the coupling cam lobe 30 can be borne by the key 34. That is, since the rotational torque received by the inner peripheral surface of the coupling cam lobe 30 is reduced, it is possible to reduce the tightening margin when the coupling cam lobe 30 is externally fitted to the shaft member 20.
- the tightening allowance can be set to such a small extent that the temperature during shrink fitting can be made lower than the tempering temperature of the coupling cam lobe 30. Thereby, it can prevent that the joint cam lobe 30 is annealed, and can suppress a hardness fall.
- the tightening margin can be reduced by providing the key 34, the heating temperature at the time of shrink fitting of the coupling cam lobe 30 can be lowered, and the decrease in hardness can be suppressed.
- the bearing portion 40 and the cam cap 41 can be used even if a slight deformation occurs in the journal portion 30B.
- the deformation can be absorbed by the gap set on the sliding surface between 41 and the journal portion 30B.
- the pair of cam lobes 30A and 30A are cam lobes with rollers, so that friction can be reduced and fuel consumption can be improved compared to cam lobes without the rollers 32. . Further, since the roller 32 itself rotates on the tappet, the cam driving torque in the low rotation range can be reduced. In particular, in this embodiment, since the pair of cam lobes 30A and 30A have the same shape and the phase difference is formed to be zero or substantially zero, the variation between the pair of intake valves or the pair of exhaust valves used in the same cylinder is minimized. Can be
- the lobe-side key groove 30k is formed on the surface of the inner peripheral surface of the mounting hole 30h opposite to the valve lift portion 31b.
- the key 34 is provided between the outer peripheral surface of the shaft member 20 and the inner peripheral surface of the mounting hole 30h of the coupling cam lobe 30 at a position facing the roller 32 with the axis of the shaft member 20 interposed therebetween. For this reason, it is possible to prevent the lobe side keyway 30k and the key 34 from affecting the driving of the valve by the cam lobe 30A.
- the key 34 is provided at a position facing the roller 32 with the shaft center of the shaft member 20 interposed therebetween, so that a slight deformation is caused. Even if this occurs, the valve lift 31b and the roller 32 can drive the valve without being affected by deformation.
- the rotational torque of the coupling cam lobe 30 can be maximally borne.
- the rotational torque (rotational force) that can be held by the key 34 can be maximized, the tightening force between the inner peripheral surface of the mounting hole 30h and the outer peripheral surface of the shaft member 20 can be reduced. The tightening allowance can be further reduced.
- the key 34 is fitted into the entire lobe side key groove 30k, no space is formed in the lobe side key groove 30k, and stress concentration can be prevented. Thereby, high intensity
- the depth of the lobe-side key groove 30k is set larger than the amount protruding from the outer peripheral surface of the shaft member 20 in a state where the key 34 is fitted into the shaft member 20.
- the key 34 is fitted into the lobe-side key groove 30k over the entire axial length of the coupling cam lobe 30, but the key 34 may be formed shorter, and at least the lobe-side key in the journal portion 30B. It only has to be fitted in the groove 30k.
- the lobe-side keyway 30k is formed so as to penetrate the coupling cam lobe 30 in the axial direction, but may have any shape as long as the coupling cam lobe 30 can be fitted into the shaft member 20 from the axial direction.
- the lobe-side key groove 30k may be formed in one cam lobe 30A and the journal portion 30B.
- the position of the lobe-side key groove 30k is not limited to the above embodiment, and may be any inner peripheral surface of the mounting hole 30h, and is preferably separated from the valve lift portion 31b.
- the shaft member 20 is also provided with the shaft-side key groove 20k, and the key 34 is press-fitted into the key groove 20k.
- the shaft member 20 and the key are integrally formed, and the shaft member 20 A key may protrude from the outer peripheral surface. Thereby, the number of parts can be reduced. Further, the strength of the shaft member 20 can be kept higher than when the shaft-side keyway 20k is provided in the shaft member 20.
- the roller shaft hole 31m is accurately positioned using a jig so that the roller shaft hole 31m is finished first, and the mounting hole 30h is finished using the roller shaft hole 31m as a reference. May be.
- the surface hardening process of the roller 32 and the roller shaft 33 is not limited to the induction hardening and tempering process, but may be other surface hardening process. Moreover, as long as high surface hardness can be given, surface hardening processing other than surface hardening processing may be given to the roller 32 and the roller shaft 33.
- the cam lobe 30 ⁇ / b> A in which the roller 32 rotates with respect to the roller shaft 33 fixed to the base cam 31 has been described.
- the roller 32 and the roller shaft 33 are fixed, and the roller shaft 33 is fixed to the base cam 31. It may be a cam lobe that rotates.
- the roller 32 may be rotatable with respect to the roller shaft 33, and the roller shaft 33 may also be rotatable with respect to the base cam 31.
- the method for fixing the roller shaft 33 is not limited to caulking, and the roller shaft 33 may be fixed to the base cam 31 by press-fitting.
- the method of fixing the coupling cam lobe 30 is not limited to shrink fitting, and may be fixed by press fitting.
- the shaft member 20 may be a solid pipe shape or may not be provided with an oil flow path or the like.
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- Gears, Cams (AREA)
Abstract
An assembled camshaft (10) is provided with: a shaft member (20) which rotates in association with the rotation of the crankshaft of an internal combustion engine; and a joined cam lobe (30) having integrally formed thereon, a pair of cam lobes (30A, 30A) equipped with rollers (32) and driving a pair of intake valves or a pair of exhaust valves, the pair of intake valves or the pair of exhaust valves being used in the same cylinder of the internal combustion engine, the joined cam lobe (30) also having integrally formed thereon, a journal section (30B) provided between the pair of cam lobes (30A, 30A), the joined cam lobe (30) having a mounting hole (30h) through which the shaft member (20) is inserted. A key (34) which, in at least the journal section (30B), extends in the axial direction of the shaft member (20) is fitted between the outer peripheral surface of the shaft member (20) and the inner peripheral surface of the mounting hole (30h).
Description
本発明は、内燃機関のクランクシャフトと連動して回転する組立カムシャフトに関する。
The present invention relates to an assembly camshaft that rotates in conjunction with a crankshaft of an internal combustion engine.
組立カムシャフトは、中空のシャフト部材に、焼きばめやかしめなどの方法によって複数のカムローブ(カム)が所定の位置に所定の位相で結合されて組み立てられたものであり、内燃機関(以下、エンジンという)の動弁機構の一部を構成する。例えば特許文献1には、所定数のカムローブをシャフト部材に挿入して位置決めし、シャフト部材の中にマンドレルを挿通してシャフト部材を拡管させてかしめることで、カムローブをシャフト部材に締結した組立カムシャフトが記載されている。
An assembly camshaft is a hollow shaft member that is assembled by combining a plurality of cam lobes (cams) at a predetermined position at a predetermined phase by a method such as shrink fitting or caulking. Part of the valve mechanism of the engine). For example, Patent Document 1 discloses an assembly in which a predetermined number of cam lobes are inserted and positioned in a shaft member, and a mandrel is inserted into the shaft member to expand the shaft member and crimp, thereby fastening the cam lobe to the shaft member. A camshaft is described.
シャフト部材にカムローブを締結して一体とする場合、シャフト部材に対するカムローブの位置と複数のカムローブ同士の位相差を精度良く組み立てる必要がある。例えば、同一気筒で用いられる一対の吸気弁又は一対の排気弁に位相のばらつきがあると、エンジンの制御に影響を及ぼし、所望の出力や排気性能が得られなくなるおそれがある。しかし、カムローブの組み立て精度を確保することは困難であり、通常は特許文献1に記載のように、組み立て後に仕上げ加工が施される。
When the cam lobe is fastened to the shaft member and integrated, the position of the cam lobe relative to the shaft member and the phase difference between the plurality of cam lobes must be assembled with high accuracy. For example, if there is a variation in phase between a pair of intake valves or a pair of exhaust valves used in the same cylinder, the engine control may be affected, and desired output and exhaust performance may not be obtained. However, it is difficult to ensure the assembly accuracy of the cam lobe, and usually finishing is performed after assembly as described in Patent Document 1.
ところで近年、カム本体の先端部にローラを回転自在に取り付け、このローラがタペットに接触しながら回転するようにしたものが提案されている(例えば、特許文献2参照)。このようなローラ付きのカムローブの場合、カムローブとタペットとの接触応力が最も高くなるカム先端部では、ローラがタペット上を転がって移動するため、効果的に摩擦を低減することができる。
By the way, in recent years, there has been proposed a roller that is rotatably attached to the tip of the cam body so that the roller rotates while contacting the tappet (see, for example, Patent Document 2). In the case of such a cam lobe with a roller, since the roller rolls and moves on the tappet at the cam tip where the contact stress between the cam lobe and the tappet is highest, the friction can be effectively reduced.
しかしながら、上記の特許文献2のようなローラ付きのカムローブの場合、ローラをカム本体に組み付けた後、ローラ付きカムローブをシャフト部材に組み立てるため、構造上の制約からカムローブの組み立て後に仕上げ加工をすることは難しい。一方で、仕上げ加工を省略するためにシャフト部材に対して複数のカムローブをそれぞれ所定の位置に所定の位相で高精度に組み立てようとすると、製造コストの増大を招くおそれがある。このような課題はローラ付きのカムローブに限らず、一般的な組立カムシャフトにおいても同様である。すなわち、組み立て後の仕上げ加工を省略するためには、予めシャフト部材に対して複数のカムローブをそれぞれ高精度に組み立てる必要がある。
However, in the case of the cam lobe with a roller as in the above-mentioned Patent Document 2, after the roller is assembled to the cam body, the cam lobe with the roller is assembled to the shaft member. Is difficult. On the other hand, if it is attempted to assemble a plurality of cam lobes with respect to the shaft member at a predetermined position with a predetermined phase with high accuracy in order to omit the finishing process, the manufacturing cost may be increased. Such a problem is not limited to a cam lobe with a roller, but also applies to a general assembly camshaft. That is, in order to omit finishing after assembly, it is necessary to assemble a plurality of cam lobes with respect to the shaft member in advance with high accuracy.
また、カムローブを焼きばめによってシャフト部材に固定する場合、締め代が大きいほどシャフト部材に対するカムローブの締め付け力が増すが、カムローブの温度をより高温にしなければ固定できないため、カムローブの硬度低下が懸念される。特に、ローラ付きのカムローブの場合、ローラの焼戻し温度よりも高い温度に加熱されるとローラが焼きなまされ、ローラの硬度が低下してしまうため、焼きばめによる固定時の温度管理は重要である。
Also, when the cam lobe is fixed to the shaft member by shrink fitting, the larger the tightening allowance, the greater the tightening force of the cam lobe against the shaft member. Is done. In particular, in the case of a cam lobe with a roller, if it is heated to a temperature higher than the tempering temperature of the roller, the roller is annealed and the hardness of the roller is lowered. It is.
本件の目的の一つは、上記のような課題に鑑み創案されたもので、コストを低減しながら組み立て精度を確保するとともに、硬度低下を抑制できるようにした、組立カムシャフトを提供することである。なお、この目的に限らず、後述する発明を実施するための形態に示す各構成により導かれる作用効果であって、従来の技術によっては得られない作用効果を奏することも本件の他の目的として位置づけることができる。
One of the purposes of the present invention was devised in view of the above-mentioned problems, and by providing an assembly camshaft that can ensure assembly accuracy while reducing costs and can suppress a decrease in hardness. is there. The present invention is not limited to this purpose, and is a function and effect derived from each configuration shown in the embodiments for carrying out the invention described later, and other effects of the present invention are to obtain a function and effect that cannot be obtained by conventional techniques. Can be positioned.
ここで開示する組立カムシャフトは、内燃機関のクランクシャフトと連動して回転するシャフト部材と、前記内燃機関の同一気筒で用いられる一対の吸気弁又は一対の排気弁を駆動する一対のカムローブ、及び、前記一対のカムローブ間に設けられるジャーナル部が一体成形され、前記シャフト部材が挿通される取付孔を有する結合カムローブと、を備える組立カムシャフトにおいて、前記一対のカムローブは何れも、ベース円部及びバルブリフト部からなるベースカムと、前記バルブリフト部の先端部に設けられ前記ベースカムに対して回転自在なローラとを有するローラ付きカムローブであり、前記シャフト部材の外周面と前記取付孔の内周面との間に、少なくとも前記ジャーナル部にて前記シャフト部材の軸方向に延びるキーが嵌め込まれる。
An assembly camshaft disclosed herein includes a shaft member that rotates in conjunction with a crankshaft of an internal combustion engine, a pair of cam lobes that drive a pair of intake valves or a pair of exhaust valves used in the same cylinder of the internal combustion engine, and An assembly camshaft comprising a coupling cam lobe having a mounting hole through which the shaft member is inserted, wherein a journal portion provided between the pair of cam lobes is integrally formed, and each of the pair of cam lobes includes a base circular portion and A cam lobe with a roller having a base cam formed of a valve lift portion and a roller provided at a tip portion of the valve lift portion and rotatable with respect to the base cam, and an outer peripheral surface of the shaft member and an inner peripheral surface of the mounting hole A key extending in the axial direction of the shaft member is fitted at least in the journal portion. Murrell.
前記シャフト部材は、前記ジャーナル部においてシリンダヘッドの上部に設けられた軸受部とカムキャップとにより挟持されることで軸支されることが好ましい。前記結合カムローブは、前記シャフト部材に外嵌されて組み立てられ、前記ベース円部に設けられ前記取付孔の内周面に軸方向に沿って形成されたキー溝(ローブ側キー溝)を有することが好ましい。前記キーは、前記シャフト部材の外周面に外方へ突設され、少なくとも前記ジャーナル部における前記キー溝に嵌め込まれることが好ましい。
It is preferable that the shaft member is pivotally supported by being sandwiched between a bearing portion and a cam cap provided at an upper portion of the cylinder head in the journal portion. The coupling cam lobe is assembled by being externally fitted to the shaft member, and has a key groove (lobe side key groove) provided in the base circle portion and formed along the axial direction on the inner peripheral surface of the mounting hole. Is preferred. It is preferable that the key protrudes outwardly on the outer peripheral surface of the shaft member and is fitted into the key groove at least in the journal portion.
前記キーは、前記シャフト部材の外周面と前記取付孔の内周面との間において、前記シャフト部材の軸心を挟んで前記ローラと対向する位置に設けられることが好ましい。
前記キー溝は、前記取付孔の内周面のうち、前記バルブリフト部と反対側の面に形成されることが好ましく、前記取付孔の軸心と前記ローラの軸心とを結ぶ直線上であって前記バルブリフト部の先端部から遠い側の面に軸方向に沿って一直線状に凹設されることがより好ましい。 It is preferable that the key is provided between the outer peripheral surface of the shaft member and the inner peripheral surface of the mounting hole at a position facing the roller across the axis of the shaft member.
The key groove is preferably formed on a surface opposite to the valve lift portion of the inner peripheral surface of the mounting hole, and on a straight line connecting the shaft center of the mounting hole and the shaft center of the roller. It is more preferable that the valve lift part is recessed in a straight line along the axial direction on the surface far from the tip part.
前記キー溝は、前記取付孔の内周面のうち、前記バルブリフト部と反対側の面に形成されることが好ましく、前記取付孔の軸心と前記ローラの軸心とを結ぶ直線上であって前記バルブリフト部の先端部から遠い側の面に軸方向に沿って一直線状に凹設されることがより好ましい。 It is preferable that the key is provided between the outer peripheral surface of the shaft member and the inner peripheral surface of the mounting hole at a position facing the roller across the axis of the shaft member.
The key groove is preferably formed on a surface opposite to the valve lift portion of the inner peripheral surface of the mounting hole, and on a straight line connecting the shaft center of the mounting hole and the shaft center of the roller. It is more preferable that the valve lift part is recessed in a straight line along the axial direction on the surface far from the tip part.
前記シャフト部材は、前記シャフト部材の軸方向に沿って形成されたシャフト側キー溝を有し、前記結合カムローブは、前記取付孔の内周面に、前記結合カムローブの軸方向全長に亘って形成されたローブ側キー溝を有することが好ましい。この場合、前記キーは、前記シャフト側キー溝及び前記ローブ側キー溝に嵌め込まれることが好ましい。
前記ローブ側キー溝の深さは、前記キーが前記シャフト部材に嵌め込まれた状態で前記シャフト部材の外周面から突出している量よりも大きく設定されることが好ましい。
前記結合カムローブは、前記取付孔の内周面に、前記結合カムローブの軸方向に沿って形成されたローブ側キー溝を有することが好ましい。この場合、前記キーは、前記シャフト部材と一体成形され、前記ローブ側キー溝に嵌め込まれることが好ましい。 The shaft member has a shaft-side key groove formed along the axial direction of the shaft member, and the coupling cam lobe is formed on the inner peripheral surface of the mounting hole over the entire axial length of the coupling cam lobe. It is preferable to have a lobed side keyway. In this case, it is preferable that the key is fitted into the shaft side keyway and the lobe side keyway.
It is preferable that the depth of the lobe-side key groove is set to be larger than an amount protruding from the outer peripheral surface of the shaft member in a state where the key is fitted into the shaft member.
The coupling cam lobe preferably has a lobe-side key groove formed along the axial direction of the coupling cam lobe on the inner peripheral surface of the mounting hole. In this case, it is preferable that the key is integrally formed with the shaft member and fitted into the lobe-side key groove.
前記ローブ側キー溝の深さは、前記キーが前記シャフト部材に嵌め込まれた状態で前記シャフト部材の外周面から突出している量よりも大きく設定されることが好ましい。
前記結合カムローブは、前記取付孔の内周面に、前記結合カムローブの軸方向に沿って形成されたローブ側キー溝を有することが好ましい。この場合、前記キーは、前記シャフト部材と一体成形され、前記ローブ側キー溝に嵌め込まれることが好ましい。 The shaft member has a shaft-side key groove formed along the axial direction of the shaft member, and the coupling cam lobe is formed on the inner peripheral surface of the mounting hole over the entire axial length of the coupling cam lobe. It is preferable to have a lobed side keyway. In this case, it is preferable that the key is fitted into the shaft side keyway and the lobe side keyway.
It is preferable that the depth of the lobe-side key groove is set to be larger than an amount protruding from the outer peripheral surface of the shaft member in a state where the key is fitted into the shaft member.
The coupling cam lobe preferably has a lobe-side key groove formed along the axial direction of the coupling cam lobe on the inner peripheral surface of the mounting hole. In this case, it is preferable that the key is integrally formed with the shaft member and fitted into the lobe-side key groove.
開示の組立カムシャフトによれば、結合カムローブにより同一気筒でのばらつきを極小化でき、また、結合カムローブをキーを用いて組み立てるため組み立て精度を確保することができる。これにより、組み立て後の仕上げ加工を要さず、コストを低減することができる。また、結合カムローブの回転トルクをキーが負担するため、結合カムローブの締め代を小さくすることができる。そのため、焼きばめ時の結合カムローブの温度を比較的低温に抑えることができ、これにより結合カムローブが焼きなましされることを防ぎ、硬度低下を抑制することができる。
According to the disclosed assembly camshaft, variations in the same cylinder can be minimized by the combined cam lobe, and assembly accuracy can be ensured because the combined cam lobe is assembled using a key. Thereby, the finishing process after an assembly is not required and cost can be reduced. Further, since the key bears the rotational torque of the combined cam lobe, the tightening margin of the combined cam lobe can be reduced. Therefore, the temperature of the coupling cam lobe at the time of shrink fitting can be suppressed to a relatively low temperature, thereby preventing the coupling cam lobe from being annealed and suppressing a decrease in hardness.
また、一対のカムローブがローラ付きのカムローブであるため、ローラが付いていないカムローブに比べて摩擦を低減することができ、燃費を向上させることができる。さらに、ローラ自体がタペット上で回転するため、低回転域でのカム駆動トルクを低減することができる。
Also, since the pair of cam lobes are cam lobes with rollers, friction can be reduced compared to cam lobes without rollers, and fuel efficiency can be improved. Furthermore, since the roller itself rotates on the tappet, the cam driving torque in the low rotation range can be reduced.
以下、図面を用いて実施の形態について説明する。なお、以下に示す実施形態はあくまでも例示に過ぎず、以下の実施形態で明示しない種々の変形や技術の適用を排除する意図はない。
Hereinafter, embodiments will be described with reference to the drawings. Note that the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described in the following embodiment.
[1.組立カムシャフトの構造]
本実施形態に係る組立カムシャフトの構造について、図1~図4を用いて説明する。図1は本組立カムシャフト10の一端側の斜視図であり、図2は図1に示す組立カムシャフト10の結合カムローブ30での軸方向に沿う縦断面図であり、結合カムローブ30で軸支された状態を示す。また、図3は図2のA-A矢視断面図、図4は図2のB-B矢視断面図である。 [1. Assembly camshaft structure]
The structure of the assembly camshaft according to this embodiment will be described with reference to FIGS. FIG. 1 is a perspective view of one end side of theassembly camshaft 10, and FIG. 2 is a longitudinal sectional view along the axial direction of the assembly camshaft 10 shown in FIG. Indicates the state that has been performed. 3 is a cross-sectional view taken along the line AA in FIG. 2, and FIG. 4 is a cross-sectional view taken along the line BB in FIG.
本実施形態に係る組立カムシャフトの構造について、図1~図4を用いて説明する。図1は本組立カムシャフト10の一端側の斜視図であり、図2は図1に示す組立カムシャフト10の結合カムローブ30での軸方向に沿う縦断面図であり、結合カムローブ30で軸支された状態を示す。また、図3は図2のA-A矢視断面図、図4は図2のB-B矢視断面図である。 [1. Assembly camshaft structure]
The structure of the assembly camshaft according to this embodiment will be described with reference to FIGS. FIG. 1 is a perspective view of one end side of the
図1及び図2に示すように、組立カムシャフト10は、中空パイプ状のシャフト部材20に、複数の結合カムローブ30が外嵌されて一体に組み立てられたものであり、エンジン(図示略)の動弁機構の一部を構成する。なお、図1では結合カムローブ30を一つだけ図示しているが、結合カムローブ30は、シャフト部材20の軸方向に気筒の数に応じて複数個設けられる。
As shown in FIGS. 1 and 2, the assembly camshaft 10 is a hollow pipe-shaped shaft member 20 that is integrally assembled with a plurality of coupling cam lobes 30 that are externally fitted, and is an engine (not shown). Part of the valve mechanism. Although only one coupling cam lobe 30 is illustrated in FIG. 1, a plurality of coupling cam lobes 30 are provided in the axial direction of the shaft member 20 according to the number of cylinders.
シャフト部材20は、その一端部20a及び図示しない他端部がシリンダヘッドのクランクシャフトの軸方向両端に立設する端壁部上縁(何れも図示略)に軸支される。シャフト部材20の一端部20aには、図示しないカムスプロケットが結合される。シャフト部材20には、エンジンのクランクシャフトの一端に結合されるクランクスプロケットとカムスプロケットとに掛け渡されるタイミングチェーンやタイミングベルト(何れも図示略)を介してクランクシャフトの回転が伝達される。これにより、シャフト部材20は、クランクシャフトと連動し、結合カムローブ30と一体となって回転する。なお、シャフト部材20の中空内部には、オイルポンプ(図示略)で圧送されたエンジンオイル(潤滑油)が流通する。
The shaft member 20 is pivotally supported by an upper end edge (not shown) of an end wall portion in which one end portion 20a and the other end portion (not shown) are erected at both axial ends of the crankshaft of the cylinder head. A cam sprocket (not shown) is coupled to one end 20 a of the shaft member 20. The rotation of the crankshaft is transmitted to the shaft member 20 via a timing chain and a timing belt (both not shown) spanned between a crank sprocket coupled to one end of the crankshaft of the engine and a cam sprocket. As a result, the shaft member 20 rotates in unison with the coupling cam lobe 30 in conjunction with the crankshaft. Engine oil (lubricating oil) pumped by an oil pump (not shown) flows through the hollow interior of the shaft member 20.
結合カムローブ30は、一対のカムローブ30A,30Aと、これら一対のカムローブ30A,30Aの間に設けられる円筒状のジャーナル部30Bとが一体成形されたものである。ここでいう一体成形とは、一体のものとしての形を作ることを意味する。つまり、結合カムローブ30は、別々に成形された同一形状の二つのカムローブがジャーナル部を介して結合されて成形されるのではなく、最初から一対のカムローブ30A,30A及びジャーナル部30Bを有する形状として成形される。
The combined cam lobe 30 is formed by integrally forming a pair of cam lobes 30A and 30A and a cylindrical journal portion 30B provided between the pair of cam lobes 30A and 30A. The term “integral molding” as used herein means making a shape as an integral one. That is, the combined cam lobe 30 is not formed by combining two cam lobes of the same shape that are separately formed via the journal part, but has a shape having a pair of cam lobes 30A, 30A and a journal part 30B from the beginning. Molded.
一対のカムローブ30A,30Aは、エンジンの同一気筒で用いられる一対の吸気弁又は一対の排気弁(以下、単にバルブともいう)を駆動するものである。一対のカムローブ30A,30Aは、同一形状で位相差がゼロ又は略ゼロとなるように形成されている。
図2及び図4に示すように、結合カムローブ30は、ジャーナル部30Bの軸方向略中央においてシリンダヘッドの上部に設けられた軸受部40とカムキャップ41とにより挟持される。これにより、組立カムシャフト10は軸受部40とカムキャップ41とに軸支される。 The pair of cam lobes 30A, 30A drives a pair of intake valves or a pair of exhaust valves (hereinafter also simply referred to as valves) used in the same cylinder of the engine. The pair of cam lobes 30A and 30A have the same shape and are formed so that the phase difference is zero or substantially zero.
As shown in FIGS. 2 and 4, thecoupling cam lobe 30 is sandwiched between a bearing portion 40 and a cam cap 41 provided at an upper portion of the cylinder head at a substantially axial center of the journal portion 30 </ b> B. As a result, the assembly camshaft 10 is pivotally supported by the bearing portion 40 and the cam cap 41.
図2及び図4に示すように、結合カムローブ30は、ジャーナル部30Bの軸方向略中央においてシリンダヘッドの上部に設けられた軸受部40とカムキャップ41とにより挟持される。これにより、組立カムシャフト10は軸受部40とカムキャップ41とに軸支される。 The pair of
As shown in FIGS. 2 and 4, the
カムキャップ41は、軸受部40の上面に組立カムシャフト10を挟んだ状態でボルト42により締結される。カムキャップ41及び軸受部40と組立カムシャフト10との間の摺動面には、図示しない微小な隙間が設けられており、この隙間には図示しないオイル供給路から潤滑用のエンジンオイルが供給される。
The cam cap 41 is fastened by a bolt 42 with the assembly cam shaft 10 sandwiched between the upper surface of the bearing portion 40. A small gap (not shown) is provided on the sliding surface between the cam cap 41 and the bearing portion 40 and the assembly camshaft 10, and engine oil for lubrication is supplied to the gap from an oil supply passage (not shown). Is done.
次に、結合カムローブ30の構造を説明する。図3に示すように、カムローブ30Aは、カム本体である板状のベースカム31と、ベースカム31に取り付けられる円筒状のローラ32とをそなえたローラ付きカムローブである。カムローブ30Aは、エンジンの各気筒におけるバルブの基端部に接続されるタペット(バルブリフターとも呼ばれる被駆動部,図示略)を駆動してバルブを開閉させる。
Next, the structure of the coupling cam lobe 30 will be described. As shown in FIG. 3, the cam lobe 30 </ b> A is a cam lobe with a roller including a plate-shaped base cam 31 that is a cam body and a cylindrical roller 32 attached to the base cam 31. The cam lobe 30A drives a tappet (a driven part, also called a valve lifter, not shown) connected to the base end of the valve in each cylinder of the engine to open and close the valve.
ベースカム31は、ベース円部31aとバルブリフト部31bとを有し、外周面(カム面)が周方向全体に亘って連続している。ベース円部31aとバルブリフト部31bとの境界線を図3中に二点鎖線で示している。
ベース円部31aは、ベースカム31の円形の部分であり、中央にシャフト部材20が挿通される円形の孔部31h(以下、カムシャフト用孔部31hという)が穿孔されている。言い換えると、ベース円部31aは、カムシャフト用孔部31hの軸心Sからの距離が一定の部分に対応する。 Thebase cam 31 has a base circle portion 31a and a valve lift portion 31b, and the outer peripheral surface (cam surface) is continuous over the entire circumferential direction. A boundary line between the base circle portion 31a and the valve lift portion 31b is indicated by a two-dot chain line in FIG.
The basecircular portion 31a is a circular portion of the base cam 31, and a circular hole portion 31h (hereinafter referred to as a cam shaft hole portion 31h) through which the shaft member 20 is inserted is drilled in the center. In other words, the base circle portion 31a corresponds to a portion where the distance from the axis S of the camshaft hole portion 31h is constant.
ベース円部31aは、ベースカム31の円形の部分であり、中央にシャフト部材20が挿通される円形の孔部31h(以下、カムシャフト用孔部31hという)が穿孔されている。言い換えると、ベース円部31aは、カムシャフト用孔部31hの軸心Sからの距離が一定の部分に対応する。 The
The base
バルブリフト部31bは、ベース円部31aの外縁を部分的に拡径方向へ膨出されてなる部分であり、タペットの頂面を押圧してバルブを開閉動作させる部分である。バルブリフト部31bは、ベースカム31の幅方向(シャフト部材20が挿通される方向,板厚方向)の中間部に、その先端部(カムトップ)31cから外周面をベース円部31a側に向かって切り欠いて形成された切欠部31nを有する。この切欠部31nには、後述するローラ32がベースカム31に対して回転自在となるように設けられる。
The valve lift part 31b is a part formed by partially bulging the outer edge of the base circle part 31a in the diameter increasing direction, and is a part that opens and closes the valve by pressing the top surface of the tappet. The valve lift portion 31b is formed at the intermediate portion in the width direction of the base cam 31 (the direction in which the shaft member 20 is inserted, the plate thickness direction), and the outer peripheral surface from the tip portion (cam top) 31c toward the base circle portion 31a. It has a notch 31n formed by notching. A roller 32 described later is provided in the notch 31n so as to be rotatable with respect to the base cam 31.
ベースカム31に欠成された切欠部31nの幅方向両側には、対向する一対のヨーク部31y,31yが形成される。一対のヨーク部31y,31yには、幅方向に貫通した孔部31m,31mが一直線上に設けられている。孔部31mは、その軸心Tがベース円部31aに形成されたカムシャフト用孔部31hの軸心Sと平行になるように形成されている。孔部31m,31mには、ローラ32をベースカム31に取り付けるためのローラシャフト33が挿通される。以下、この孔部31mをローラシャフト用孔部31mという。ローラシャフト33の端部周縁には、外径側に突出した爪部(図示略)が設けられており、この爪部がベースカム31のヨーク部31yの端面に打ち付けられてかしめられることで、ベースカム31にローラシャフト33が固定される。
A pair of opposing yoke portions 31y and 31y are formed on both sides in the width direction of the notch portion 31n formed in the base cam 31. In the pair of yoke portions 31y, 31y, holes 31m, 31m penetrating in the width direction are provided on a straight line. The hole 31m is formed such that its axis T is parallel to the axis S of the camshaft hole 31h formed in the base circle 31a. A roller shaft 33 for attaching the roller 32 to the base cam 31 is inserted through the holes 31m and 31m. Hereinafter, the hole 31m is referred to as a roller shaft hole 31m. A claw portion (not shown) projecting to the outer diameter side is provided on the peripheral edge of the roller shaft 33, and this claw portion is struck against the end surface of the yoke portion 31y of the base cam 31 to be caulked. A roller shaft 33 is fixed to 31.
図2及び図3に示すように、ローラ32は、その中心に挿通されるローラシャフト33を介して、ベースカム31に回転自在に組み付けられる。ローラ32の内周面32hは、ローラシャフト33のすべり軸受として機能する。ローラ32は、その外周面の一部がバルブリフト部31bの先端部31cの外周面よりも外側に突出するように取り付けられる。先端部31cからのローラ32の突出量は、ベースカム31の形状とローラ32の外径とよって決まる。
2 and 3, the roller 32 is rotatably assembled to the base cam 31 via a roller shaft 33 inserted through the center thereof. The inner peripheral surface 32 h of the roller 32 functions as a sliding bearing for the roller shaft 33. The roller 32 is attached such that a part of its outer peripheral surface protrudes outside the outer peripheral surface of the tip end portion 31c of the valve lift portion 31b. The amount of protrusion of the roller 32 from the tip portion 31 c is determined by the shape of the base cam 31 and the outer diameter of the roller 32.
ローラ付きのカムローブ30Aは、組立カムシャフト10が回転すると、まずはベースカム31のバルブリフト部31bがタペットと接触し、タペットを押圧する。バルブリフト部31bは、組立カムシャフト10の回転に伴ってタペットを押し下げていく。そして、ある回転角でタペットとの接触位置がバルブリフト部31bからローラ32へと移り、今度はローラ32がタペットを押圧することになる。ローラ32は、タペット上を転がりながら移動してタペットを押し下げ、ついにはバルブリフト量が最大となる。
In the cam lobe 30A with a roller, when the assembly cam shaft 10 rotates, first, the valve lift 31b of the base cam 31 comes into contact with the tappet and presses the tappet. The valve lift 31b pushes down the tappet as the assembly camshaft 10 rotates. Then, at a certain rotation angle, the position of contact with the tappet moves from the valve lift 31b to the roller 32, and this time the roller 32 presses the tappet. The roller 32 moves while rolling on the tappet to push down the tappet, and finally the valve lift amount is maximized.
その後は、バルブリフト量が減少し、タペットとの接触位置がローラ32からバルブリフト部31bへと変化して、再びバルブリフト部31bがタペットを押圧することになる。そして、バルブリフト部31bがタペットから離れて、ベース円部31aがタペットに対向するとバルブリフト量はゼロとなる。このように、ローラ付きのカムローブ30Aは、ローラ32がタペット上を転がりながら移動してタペットを押圧する分、ローラ32が付いていないカムローブに比べて摩擦を低減することができる。また、ローラ32自体がタペット上で回転するため、低回転域でのカム駆動トルクを低減することができるなど、優れた効果が得られる。
After that, the valve lift amount decreases, the contact position with the tappet changes from the roller 32 to the valve lift portion 31b, and the valve lift portion 31b presses the tappet again. When the valve lift part 31b moves away from the tappet and the base circle part 31a faces the tappet, the valve lift amount becomes zero. Thus, the cam lobe 30A with a roller can reduce friction compared to a cam lobe without the roller 32 because the roller 32 moves while rolling on the tappet and presses the tappet. Further, since the roller 32 itself rotates on the tappet, an excellent effect can be obtained, such as reduction of cam driving torque in a low rotation range.
ここでは、結合カムローブ30の一対のカムローブ30A,30Aは、上記のように同一形状であって位相差がゼロ又は略ゼロに形成されている。すなわち、一対のカムローブ30A,30Aのベースカム31,31は、周方向において同じ位置(角度)にバルブリフト部31b,31bが設けられ、同一のローラ32,32が同一の突出量となるようにベースカム31,31に組み付けられる。そのため、同一気筒で用いられる一対の吸気弁又は一対の排気弁のばらつきが極小化される。
Here, the pair of cam lobes 30A and 30A of the combined cam lobe 30 have the same shape as described above and have a phase difference of zero or substantially zero. That is, the base cams 31 and 31 of the pair of cam lobes 30A and 30A are provided with valve lift portions 31b and 31b at the same position (angle) in the circumferential direction so that the same rollers 32 and 32 have the same protruding amount. 31 and 31. Therefore, the variation between a pair of intake valves or a pair of exhaust valves used in the same cylinder is minimized.
一方、ジャーナル部30Bは、図2に示すように、一対のカムローブ30A,30Aの各ベース円部31aの対向する端面同士を接続するように一対のカムローブ30A,30Aと一体で形成された円筒部である。ジャーナル部30Bは、上記のように軸受部40とカムキャップ41とに挟持されて軸支される部分である。
On the other hand, as shown in FIG. 2, the journal portion 30B is a cylindrical portion formed integrally with the pair of cam lobes 30A and 30A so as to connect the opposing end surfaces of the base circular portions 31a of the pair of cam lobes 30A and 30A. It is. The journal portion 30B is a portion that is supported by the bearing portion 40 and the cam cap 41 as described above.
結合カムローブ30は、シャフト部材20が挿通される取付孔30h(すなわちカムシャフト用孔部31h,31h及びジャーナル部30Bの内周面)を有する。取付孔30hの径(内径)は、シャフト部材20の外径よりも小さく形成されている。つまり、結合カムローブ30とシャフト部材20との間に締め代が設けられており、結合カムローブ30はシャフト部材20に対して焼きばめにより嵌め込まれる。言い換えると、結合カムローブ30は組み立て時に所定の温度まで加熱され、取付孔30hが膨張してシャフト部材20の外径よりも広がったところでシャフト部材20に外嵌される。
The coupling cam lobe 30 has a mounting hole 30h (that is, the cam shaft hole portions 31h and 31h and the inner peripheral surface of the journal portion 30B) through which the shaft member 20 is inserted. The diameter (inner diameter) of the mounting hole 30 h is smaller than the outer diameter of the shaft member 20. That is, a fastening margin is provided between the coupling cam lobe 30 and the shaft member 20, and the coupling cam lobe 30 is fitted into the shaft member 20 by shrink fitting. In other words, the coupling cam lobe 30 is heated to a predetermined temperature at the time of assembly, and the attachment hole 30h expands and is fitted onto the shaft member 20 when it is wider than the outer diameter of the shaft member 20.
なお、このときの所定の温度は、後述のローラ32の焼戻し温度よりも低い温度に設定されており、これにより組み立て時にローラ32が焼きなましされることが防止される。換言すると、締め代は、焼きばめ時の温度がローラ32の焼戻し温度よりも低い温度に設定された場合であっても、結合カムローブ30をシャフト部材20に組み立てられる大きさに設定される。
In addition, the predetermined temperature at this time is set to a temperature lower than a tempering temperature of a roller 32 which will be described later, thereby preventing the roller 32 from being annealed during assembly. In other words, the tightening allowance is set to such a size that the coupling cam lobe 30 can be assembled to the shaft member 20 even when the temperature during shrink fitting is set to a temperature lower than the tempering temperature of the roller 32.
図2~図4に示すように、結合カムローブ30とシャフト部材20との間には、軸方向に延びるキー34が嵌め込まれている。キー34は、シャフト部材20の回転運動や回転トルクを結合カムローブ30へ伝達するとともに、結合カムローブ30の回転トルクを負担するための部材であり、細長い直方体形状に形成されている。ここでは、キー34は結合カムローブ30の軸方向長さと同一の長さに形成されている。
2 to 4, a key 34 extending in the axial direction is fitted between the coupling cam lobe 30 and the shaft member 20. As shown in FIG. The key 34 is a member for transmitting the rotational motion and rotational torque of the shaft member 20 to the coupling cam lobe 30 and bearing the rotational torque of the coupling cam lobe 30 and is formed in an elongated rectangular parallelepiped shape. Here, the key 34 is formed to have the same length as the axial length of the coupling cam lobe 30.
なお、結合カムローブ30の回転トルクはキー34により保持される(すなわちキー34が回転トルクを受ける)ため、結合カムローブ30のシャフト部材20に対する締め付け力をそれほど大きくしなくても、結合カムローブ30がシャフト部材20に対して周方向にずれるようなことがない。そのため、結合カムローブ30をシャフト部材20に焼きばめにより固定する場合の締め代を小さく設定することができる。言い換えると、小さな締め代であっても、キー34を設けることで結合カムローブ30をシャフト部材20に対して確実に固定することができる。
Since the rotational torque of the coupling cam lobe 30 is held by the key 34 (that is, the key 34 receives the rotational torque), the coupling cam lobe 30 can be connected to the shaft even if the tightening force of the coupling cam lobe 30 on the shaft member 20 is not increased so much. The member 20 is not shifted in the circumferential direction. For this reason, it is possible to set a small fastening margin when the coupling cam lobe 30 is fixed to the shaft member 20 by shrink fitting. In other words, the coupling cam lobe 30 can be reliably fixed to the shaft member 20 by providing the key 34 even with a small allowance.
シャフト部材20の外周面には、キー34が圧入されるキー溝20k(以下、シャフト側キー溝20kという)が形成されている。シャフト側キー溝20kは、シャフト部材20の外周面のうち、結合カムローブ30のカムトップ31c側に位置する面とは反対側の位置(180度ずれた位置)に、シャフト部材20の軸方向に沿って一直線状に凹設される。シャフト側キー溝20kは、キー34の形状に対応した形状に形成される。例えば、キー34の長さ及び幅と同等の長さ及び幅に形成され、キー34の高さの略半分の深さに形成される。
A key groove 20k into which the key 34 is press-fitted (hereinafter referred to as a shaft-side key groove 20k) is formed on the outer peripheral surface of the shaft member 20. The shaft-side keyway 20k is located in the axial direction of the shaft member 20 at a position (a position shifted by 180 degrees) on the opposite side of the outer peripheral surface of the shaft member 20 from the surface located on the cam top 31c side of the coupling cam lobe 30. It is recessed along a straight line. The shaft side keyway 20 k is formed in a shape corresponding to the shape of the key 34. For example, it is formed to have a length and width equivalent to the length and width of the key 34, and is formed to a depth that is approximately half the height of the key 34.
一方、結合カムローブ30の取付孔30hには、バルブリフト部31bと反対側の内周面にキー34が嵌め込まれるキー溝30k(以下、ローブ側キー溝30kという)が形成されている。ここでは、ローブ側キー溝30kは、取付孔30hの内周面のうち、カムシャフト用孔部31hの軸心Sとローラシャフト用孔部31mの軸心Tとを結ぶ直線上であってカムトップ31cから遠い側の面に、結合カムローブ30の軸方向に沿って一直線状に凹設される。ローブ側キー溝30kは、結合カムローブ30がシャフト部材20に組み立てられたときに、シャフト側キー溝20kと重なる位置に設けられる。
On the other hand, a key groove 30k (hereinafter referred to as a lobe-side key groove 30k) into which the key 34 is fitted is formed in the mounting hole 30h of the coupling cam lobe 30 on the inner peripheral surface opposite to the valve lift portion 31b. Here, the lobe side keyway 30k is a straight line connecting the axis S of the camshaft hole 31h and the axis T of the roller shaft hole 31m on the inner peripheral surface of the mounting hole 30h. On the surface far from the top 31c, it is recessed in a straight line along the axial direction of the coupling cam lobe 30. The lobe-side key groove 30k is provided at a position overlapping the shaft-side key groove 20k when the coupling cam lobe 30 is assembled to the shaft member 20.
ローブ側キー溝30kは、一方のカムローブ30Aのジャーナル部30Bとは反対側の端面から、他方のカムローブ30Aのジャーナル部30Bとは反対側の端面まで延設されている。すなわち、ローブ側キー溝30kは、結合カムローブ30を軸方向に貫通して(軸方向全長に亘って)形成されている。また、ローブ側キー溝30kの幅はキー34の幅と同等に形成され、ローブ側キー溝30kの深さは、キー34のシャフト部材20の外周面からの突出量と同等かやや大きく形成されている。
The lobe-side keyway 30k extends from the end surface of the one cam lobe 30A opposite to the journal portion 30B to the end surface of the other cam lobe 30A opposite to the journal portion 30B. That is, the lobe-side key groove 30k is formed so as to penetrate the coupling cam lobe 30 in the axial direction (over the entire length in the axial direction). Further, the width of the lobe-side key groove 30k is formed to be equal to the width of the key 34, and the depth of the lobe-side key groove 30k is formed to be equal to or slightly larger than the protruding amount of the key 34 from the outer peripheral surface of the shaft member 20. ing.
言い換えると、ローブ側キー溝30kの深さは、キー34がシャフト部材20に嵌め込まれた状態でシャフト部材20の外周面から突出している量よりも大きく設定される。これにより、結合カムローブ30をシャフト部材20に嵌め込む際に、キー34とローブ側キー溝30kとの間に隙間が形成されるため、キー嵌め込み時の結合カムローブ30のカム面の変形が回避される。
In other words, the depth of the lobe-side keyway 30k is set to be larger than the amount protruding from the outer peripheral surface of the shaft member 20 in a state where the key 34 is fitted in the shaft member 20. Accordingly, when the coupling cam lobe 30 is fitted into the shaft member 20, a gap is formed between the key 34 and the lobe-side key groove 30k, so that the deformation of the cam surface of the coupling cam lobe 30 when the key is fitted is avoided. The
キー34は、シャフト側キー溝20kに圧入されて、シャフト部材20の外周面から外方に突設される。そして、結合カムローブ30の組み立て時には、この突設されたキー34にローブ側キー溝30kが嵌まるように、結合カムローブ30がシャフト部材20の軸方向から嵌め込まれる。ここでは、キー34は、結合カムローブ30の軸方向全長に亘ってローブ側キー溝30kに嵌め込まれる。なお、結合カムローブ30はシャフト部材20に対してしまりばめとなるが、キー34はローブ側キー溝30kに対して中間ばめとなる。
The key 34 is press-fitted into the shaft-side keyway 20k and protrudes outward from the outer peripheral surface of the shaft member 20. When the coupling cam lobe 30 is assembled, the coupling cam lobe 30 is fitted from the axial direction of the shaft member 20 such that the lobe-side key groove 30k is fitted to the protruding key 34. Here, the key 34 is fitted into the lobe-side key groove 30 k over the entire axial length of the coupling cam lobe 30. The coupling cam lobe 30 is an interference fit with respect to the shaft member 20, while the key 34 is an intermediate fit with respect to the lobe side key groove 30k.
[2.製造方法]
次に、本実施形態に係る組立カムシャフト10の製造方法の一例について説明する。組立カムシャフト10は、一対のカムローブ30A,30Aのベースカム31,31にそれぞれローラ32,32が組み付けられ、結合カムローブ30が完成した状態でシャフト部材20に嵌め込まれる。なお、結合カムローブ30は、エンジンの気筒数に応じて複数製造される。以下、詳述する。 [2. Production method]
Next, an example of a method for manufacturing theassembly camshaft 10 according to the present embodiment will be described. The assembly camshaft 10 is fitted into the shaft member 20 in a state where the rollers 32, 32 are assembled to the base cams 31, 31 of the pair of cam lobes 30A, 30A, respectively, and the combined cam lobe 30 is completed. A plurality of coupled cam lobes 30 are manufactured according to the number of cylinders of the engine. Details will be described below.
次に、本実施形態に係る組立カムシャフト10の製造方法の一例について説明する。組立カムシャフト10は、一対のカムローブ30A,30Aのベースカム31,31にそれぞれローラ32,32が組み付けられ、結合カムローブ30が完成した状態でシャフト部材20に嵌め込まれる。なお、結合カムローブ30は、エンジンの気筒数に応じて複数製造される。以下、詳述する。 [2. Production method]
Next, an example of a method for manufacturing the
本製造方法は、ローラ32に対する突出量の設定工程,選定工程及び表面処理工程と、一対のカムローブ30A,30Aのベースカム31,31及びジャーナル部30Bに対する荒加工工程,仕上げ加工工程,研削工程及び表面処理工程とを有する。さらに、ベースカム31,31にそれぞれローラ32,32を組み付ける組付工程と、結合カムローブ30をシャフト部材20へ嵌め込んで組み立てる組立工程とを有する。
In this manufacturing method, a protrusion amount setting process, a selection process, and a surface treatment process for the roller 32, and a roughing process, a finishing process, a grinding process, and a surface for the base cams 31, 31 and the journal portion 30B of the pair of cam lobes 30A, 30A are provided. Processing steps. Furthermore, it has an assembling process for assembling the rollers 32, 32 to the base cams 31, 31, respectively, and an assembling process for fitting the coupling cam lobe 30 into the shaft member 20 for assembly.
最初に、ローラ32に対する各工程について説明する。まず、ベースカム31の外周面からのローラ32の突出量を設定し(設定工程)、その突出量となる外径を有するローラ32をカムローブ30Aの個数だけ用意する(選定工程)。次に、ローラ32とローラシャフト33とを組み付け状態にする前に、ローラ32及びローラシャフト33に対してそれぞれ表面硬化処理を実施する。ここでは表面硬化処理として、一般的な高周波焼入れ焼戻しを実施する。これにより、ローラ32及びローラシャフト33の各表面には、比較的厚い硬化層が形成される(表面処理工程)。
First, each process for the roller 32 will be described. First, the protrusion amount of the roller 32 from the outer peripheral surface of the base cam 31 is set (setting step), and the rollers 32 having the outer diameters corresponding to the protrusion amount are prepared for the number of cam lobes 30A (selection step). Next, before the roller 32 and the roller shaft 33 are assembled, a surface hardening process is performed on the roller 32 and the roller shaft 33, respectively. Here, general induction hardening and tempering are performed as the surface hardening treatment. Thereby, a relatively thick hardened layer is formed on each surface of the roller 32 and the roller shaft 33 (surface treatment process).
次に、一対のカムローブ30A,30Aのベースカム31,31及びジャーナル部30Bに対する各工程について説明する。ベースカム31,31及びジャーナル部30Bの各工程の前段階として、ベースカム31,31及びジャーナル部30Bの基礎となる部品を鍛造により一体成形する。次いで、この鍛造品を荒加工して、切欠部31nとなる部分を形成するとともに、シャフト部材20の取付孔30h及びローラシャフト用孔部31mとなる部分を穴あけ加工する。
Next, each process for the base cams 31 and 31 and the journal portion 30B of the pair of cam lobes 30A and 30A will be described. As a pre-stage of each process of the base cams 31 and 31 and the journal part 30B, the parts that form the basis of the base cams 31 and 31 and the journal part 30B are integrally formed by forging. Next, the forged product is roughly processed to form a portion that becomes the notch 31n, and a portion that becomes the mounting hole 30h of the shaft member 20 and the roller shaft hole 31m is drilled.
また、この鍛造品の外周面を荒加工してベースカム31の最終的なカムプロフィールに近い形状に形成する(荒加工工程)。ここでいう最終的なカムプロフィールに近い形状とは、外周面を仕上げ加工(すなわち研削)するだけで、所望のカムプロフィールとなる形状をいう。なお、荒加工工程を省略し、鍛造品を成形する段階で、切欠部31nや取付孔30h,ローラシャフト用孔部31mとなる部分を形成し、外周面をベースカム31の最終的なカムプロフィールに近い形状に形成してもよい。
Also, the outer peripheral surface of this forged product is roughed to form a shape close to the final cam profile of the base cam 31 (roughing process). The shape close to the final cam profile here refers to a shape that becomes a desired cam profile only by finishing (that is, grinding) the outer peripheral surface. The rough machining step is omitted, and at the stage of forming the forged product, the notch 31n, the mounting hole 30h, and the roller shaft hole 31m are formed, and the outer peripheral surface becomes the final cam profile of the base cam 31. You may form in a near shape.
荒加工工程後の鍛造品は、仕上げ加工工程において、最終的なベースカム31の形状に形成される。仕上げ加工工程は、例えばNC旋盤のように数値制御で加工が可能な装置を用いても行ってもよく、手作業で加工してもよい。荒加工工程後の鍛造品には、まず、シャフト部材20の取付孔30hを仕上げ加工し、次いでこの取付孔30hを基準にしてローラシャフト用孔部31mを位置決めして仕上げ加工する。
The forged product after the roughing process is formed into the final shape of the base cam 31 in the finishing process. The finishing process may be performed using a device capable of performing numerical control, such as an NC lathe, or may be performed manually. For the forged product after the roughing process, first, the mounting hole 30h of the shaft member 20 is finished, and then the roller shaft hole 31m is positioned and finished with reference to the mounting hole 30h.
なお、取付孔30hは、シャフト部材20の外径よりもやや小さい径に形成され、ローラシャフト用孔部31mは、ローラシャフト33の径よりもやや大きい径に形成される。これは、結合カムローブ30はシャフト部材20に対して焼きばめにより固定されるのに対し、ローラシャフト33はベースカム31に対してかしめにより固定されるためである。
The mounting hole 30 h is formed to have a diameter slightly smaller than the outer diameter of the shaft member 20, and the roller shaft hole 31 m is formed to have a diameter slightly larger than the diameter of the roller shaft 33. This is because the coupling cam lobe 30 is fixed to the shaft member 20 by shrink fitting while the roller shaft 33 is fixed to the base cam 31 by caulking.
取付孔30h及びローラシャフト用孔部31mが形成された鍛造品は、続いてその外周面が研削される(研削工程)。例えば、取付孔30h及びローラシャフト用孔部31mをそれぞれチャックで固定することで鍛造品を支持し、その外周面に高速回転する研削砥石を接触させながら、所定の送り量(切り込み量)だけ鍛造品側へと進め、鍛造品の外周面を研削する。これにより、所望のカムプロフィールを有するベースカム31が完成する。
The forged product in which the mounting hole 30h and the roller shaft hole 31m are formed is then ground on its outer peripheral surface (grinding step). For example, the mounting hole 30h and the roller shaft hole 31m are each fixed by a chuck to support the forged product, and forging is performed for a predetermined feed amount (cutting amount) while contacting a grinding wheel rotating at high speed on the outer peripheral surface. Proceed to the product side and grind the outer peripheral surface of the forged product. Thereby, the base cam 31 having a desired cam profile is completed.
完成した一対のベースカム31,31及びジャーナル部30Bは、表面処理工程において、例えば一般的なガス窒化処理や焼入れ焼戻し処理が施される。なお、ジャーナル部30Bの表面処理は省略してもよい。
The completed pair of base cams 31 and 31 and the journal portion 30B are subjected to, for example, a general gas nitriding treatment or quenching and tempering treatment in the surface treatment process. Note that the surface treatment of the journal portion 30B may be omitted.
以上の工程を経た一対のベースカム31,31には、組付工程において、ローラ32がローラシャフト33を介してそれぞれ回転自在に組み付けられる。具体的には、ローラ32は、その中心の貫通孔がベースカム31のヨーク部31y,31yに形成されたローラシャフト用孔部31m,31mと重なり、二つのヨーク部31y,31yとの隙間が略同等となるように、切欠部31nの幅方向中心部に配置される。この状態で、ローラシャフト33が、一方のヨーク部31yのローラシャフト用孔部31mに挿通され、続いてローラ32の貫通孔に挿通され、さらに他方のヨーク部31yのローラシャフト用孔部31mに挿通される。そして、ローラシャフト33の両端部をかしめによって拡径することで、ベースカム31に固定される。
In the assembling process, the rollers 32 are rotatably assembled to the pair of base cams 31, 31 that have undergone the above processes, via the roller shaft 33. Specifically, the roller 32 has a central through hole overlapped with the roller shaft hole portions 31m and 31m formed in the yoke portions 31y and 31y of the base cam 31, and the gap between the two yoke portions 31y and 31y is substantially omitted. It arrange | positions in the center part of the width direction of the notch part 31n so that it may become equivalent. In this state, the roller shaft 33 is inserted into the roller shaft hole 31m of the one yoke portion 31y, subsequently inserted into the through hole of the roller 32, and further into the roller shaft hole 31m of the other yoke portion 31y. It is inserted. And it fixes to the base cam 31 by expanding the both ends of the roller shaft 33 by caulking.
このように、一対のカムローブ30A,30Aのベースカム31,31にそれぞれローラ32,32が取り付けられることで、結合カムローブ30が製造される。なお、ローラ32に対する各工程とベースカム31,31及びジャーナル部30Bに対する各工程とは、何れを先に実施してもよいし、同時に実施してもよい。
In this way, the combined cam lobe 30 is manufactured by attaching the rollers 32 and 32 to the base cams 31 and 31 of the pair of cam lobes 30A and 30A, respectively. Any of the steps for the roller 32 and the steps for the base cams 31 and 31 and the journal portion 30B may be performed first or simultaneously.
組立工程では、まずシャフト部材20のシャフト側キー溝20kにキー34を圧入する。そして、シャフト部材20の外周面から突設されたキー34にローブ側キー溝30kが嵌まるように、所定の温度まで加熱した結合カムローブ30をシャフト部材20に対して軸方向から挿入する。これにより、結合カムローブ30の温度が低下すれば、シャフト部材20に対して結合カムローブ30が強固に固定された組立カムシャフト10が完成する。
In the assembly process, the key 34 is first press-fitted into the shaft-side keyway 20k of the shaft member 20. Then, the coupling cam lobe 30 heated to a predetermined temperature is inserted into the shaft member 20 from the axial direction so that the lobe-side key groove 30k is fitted to the key 34 protruding from the outer peripheral surface of the shaft member 20. Thus, when the temperature of the coupling cam lobe 30 is lowered, the assembly camshaft 10 in which the coupling cam lobe 30 is firmly fixed to the shaft member 20 is completed.
[3.効果]
したがって、本実施形態に係る組立カムシャフト10によれば、結合カムローブ30を一体成形することで同一気筒でのばらつきを極小化でき、また、結合カムローブ30をキー34を用いて組み立てるため、組み立て精度を確保することができる。これにより、組立工程後の仕上げ加工工程を省略することができるので、製造コストを低減することができる。また、同一気筒内でのばらつきを極小化できるため、エンジン制御の精度を高めることができ、ひいては出力向上や排気性能向上を実現することができる。 [3. effect]
Therefore, according to theassembly camshaft 10 according to the present embodiment, the variation in the same cylinder can be minimized by integrally forming the coupling cam lobe 30 and the coupling cam lobe 30 is assembled using the key 34. Can be secured. Thereby, since the finishing process after an assembly process can be omitted, the manufacturing cost can be reduced. In addition, since variations within the same cylinder can be minimized, the accuracy of engine control can be increased, and as a result, output and exhaust performance can be improved.
したがって、本実施形態に係る組立カムシャフト10によれば、結合カムローブ30を一体成形することで同一気筒でのばらつきを極小化でき、また、結合カムローブ30をキー34を用いて組み立てるため、組み立て精度を確保することができる。これにより、組立工程後の仕上げ加工工程を省略することができるので、製造コストを低減することができる。また、同一気筒内でのばらつきを極小化できるため、エンジン制御の精度を高めることができ、ひいては出力向上や排気性能向上を実現することができる。 [3. effect]
Therefore, according to the
また、結合カムローブ30をシャフト部材20に外嵌するときにキー34が用いられるため、結合カムローブ30の回転トルクをキー34に負担させることができる。つまり、結合カムローブ30の内周面で受ける回転トルクが小さくなるので、結合カムローブ30をシャフト部材20に外嵌するときの締め代を小さくすることができる。例えば、結合カムローブ30をシャフト部材20に組み立てる場合、焼きばめ時の温度を結合カムローブ30の焼戻し温度よりも低くできる程度の小さな締め代に設定することができる。これにより、結合カムローブ30が焼きなまされることを防ぐことができ、硬度低下を抑制することができる。換言すると、キー34を設けることで締め代を小さくできるため、結合カムローブ30の焼きばめ時の加熱温度を低くすることができ、硬度低下を抑制できる。
Further, since the key 34 is used when the coupling cam lobe 30 is fitted on the shaft member 20, the rotational torque of the coupling cam lobe 30 can be borne by the key 34. That is, since the rotational torque received by the inner peripheral surface of the coupling cam lobe 30 is reduced, it is possible to reduce the tightening margin when the coupling cam lobe 30 is externally fitted to the shaft member 20. For example, when assembling the coupling cam lobe 30 to the shaft member 20, the tightening allowance can be set to such a small extent that the temperature during shrink fitting can be made lower than the tempering temperature of the coupling cam lobe 30. Thereby, it can prevent that the joint cam lobe 30 is annealed, and can suppress a hardness fall. In other words, since the tightening margin can be reduced by providing the key 34, the heating temperature at the time of shrink fitting of the coupling cam lobe 30 can be lowered, and the decrease in hardness can be suppressed.
さらに、キー34が軸受部40とカムキャップ41とにより挟持されるジャーナル部30Bにおけるローブ側キー溝30kに嵌め込まれるため、ジャーナル部30Bに微小の変形が生じたとしても、軸受部40及びカムキャップ41とジャーナル部30Bとの摺動面に設定される隙間により変形を吸収することができる。
Furthermore, since the key 34 is fitted into the lobe-side key groove 30k in the journal portion 30B held between the bearing portion 40 and the cam cap 41, the bearing portion 40 and the cam cap can be used even if a slight deformation occurs in the journal portion 30B. The deformation can be absorbed by the gap set on the sliding surface between 41 and the journal portion 30B.
また、上記の組立カムシャフト10は、一対のカムローブ30A,30Aがローラ付きのカムローブであるため、ローラ32が付いていないカムローブに比べて摩擦を低減することができ、燃費を向上させることができる。また、ローラ32自体がタペット上で回転するため、低回転域でのカム駆動トルクを低減することができる。特に本実施形態では、一対のカムローブ30A,30Aが同一形状であって位相差がゼロ又は略ゼロに形成されているため、同一気筒で用いられる一対の吸気弁又は一対の排気弁のばらつきを極小化することができる。
Further, in the assembly camshaft 10, the pair of cam lobes 30A and 30A are cam lobes with rollers, so that friction can be reduced and fuel consumption can be improved compared to cam lobes without the rollers 32. . Further, since the roller 32 itself rotates on the tappet, the cam driving torque in the low rotation range can be reduced. In particular, in this embodiment, since the pair of cam lobes 30A and 30A have the same shape and the phase difference is formed to be zero or substantially zero, the variation between the pair of intake valves or the pair of exhaust valves used in the same cylinder is minimized. Can be
また、上記の組立カムシャフト10は、ローブ側キー溝30kが取付孔30hの内周面のうちバルブリフト部31bと反対側の面に形成されている。言い換えると、キー34が、シャフト部材20の外周面と結合カムローブ30の取付孔30hの内周面との間において、シャフト部材20の軸心を挟んでローラ32と対向する位置に設けられる。このため、カムローブ30Aによるバルブの駆動に対して、ローブ側キー溝30k及びキー34が影響しないようにすることができる。すなわち、カムローブ30Aのうちタペットに接触するのはバルブリフト部31b及びローラ32であるため、キー34を、シャフト部材20の軸心を挟んでローラ32と対向する位置に設けることで、微小の変形が生じたとしても、バルブリフト部31b及びローラ32は変形の影響を受けずにバルブを駆動することができる。
Further, in the assembly camshaft 10 described above, the lobe-side key groove 30k is formed on the surface of the inner peripheral surface of the mounting hole 30h opposite to the valve lift portion 31b. In other words, the key 34 is provided between the outer peripheral surface of the shaft member 20 and the inner peripheral surface of the mounting hole 30h of the coupling cam lobe 30 at a position facing the roller 32 with the axis of the shaft member 20 interposed therebetween. For this reason, it is possible to prevent the lobe side keyway 30k and the key 34 from affecting the driving of the valve by the cam lobe 30A. That is, since the valve lift portion 31b and the roller 32 make contact with the tappet in the cam lobe 30A, the key 34 is provided at a position facing the roller 32 with the shaft center of the shaft member 20 interposed therebetween, so that a slight deformation is caused. Even if this occurs, the valve lift 31b and the roller 32 can drive the valve without being affected by deformation.
また、キー34は、結合カムローブ30の軸方向全長に亘ってローブ側キー溝30kに嵌め込まれるため、結合カムローブ30の回転トルクを最大限負担することができる。言い換えると、キー34により保持できる回転トルク(回転力)を最大とすることができるので、取付孔30hの内周面とシャフト部材20の外周面との締め付け力を小さくすることができ、これにより締め代をより小さくすることができる。また、ローブ側キー溝30kの全体にキー34が嵌め込まれるため、ローブ側キー溝30kに空間ができず、応力集中の発生を防ぐことができる。これにより、組立カムシャフト10全体において高い強度を確保することができる。
Further, since the key 34 is fitted into the lobe-side key groove 30k over the entire axial length of the coupling cam lobe 30, the rotational torque of the coupling cam lobe 30 can be maximally borne. In other words, since the rotational torque (rotational force) that can be held by the key 34 can be maximized, the tightening force between the inner peripheral surface of the mounting hole 30h and the outer peripheral surface of the shaft member 20 can be reduced. The tightening allowance can be further reduced. Further, since the key 34 is fitted into the entire lobe side key groove 30k, no space is formed in the lobe side key groove 30k, and stress concentration can be prevented. Thereby, high intensity | strength is securable in the assembly cam shaft 10 whole.
また、ローブ側キー溝30kの深さは、キー34がシャフト部材20に嵌め込まれた状態でシャフト部材20の外周面から突出している量よりも大きく設定される。これにより、結合カムローブ30をシャフト部材20に嵌め込む際に、キー34とローブ側キー溝30kとの間に隙間が形成されるため、キー嵌め込み時の結合カムローブ30のカム面の変形を回避することができる。
Further, the depth of the lobe-side key groove 30k is set larger than the amount protruding from the outer peripheral surface of the shaft member 20 in a state where the key 34 is fitted into the shaft member 20. Thus, when the coupling cam lobe 30 is fitted into the shaft member 20, a gap is formed between the key 34 and the lobe-side key groove 30k, so that deformation of the cam surface of the coupling cam lobe 30 when the key is fitted is avoided. be able to.
[4.その他]
以上、本発明の実施形態を説明したが、本発明は上記実施形態に限定されるものではなく、本発明の趣旨を逸脱しない範囲で種々変形することが可能である。
上記実施形態では、キー34は結合カムローブ30の軸方向全長に亘ってローブ側キー溝30kに嵌め込まれているが、キー34はもっと短く形成されていてもよく、少なくともジャーナル部30Bにおけるローブ側キー溝30kに嵌め込まれていればよい。 [4. Others]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
In the above embodiment, the key 34 is fitted into the lobe-sidekey groove 30k over the entire axial length of the coupling cam lobe 30, but the key 34 may be formed shorter, and at least the lobe-side key in the journal portion 30B. It only has to be fitted in the groove 30k.
以上、本発明の実施形態を説明したが、本発明は上記実施形態に限定されるものではなく、本発明の趣旨を逸脱しない範囲で種々変形することが可能である。
上記実施形態では、キー34は結合カムローブ30の軸方向全長に亘ってローブ側キー溝30kに嵌め込まれているが、キー34はもっと短く形成されていてもよく、少なくともジャーナル部30Bにおけるローブ側キー溝30kに嵌め込まれていればよい。 [4. Others]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
In the above embodiment, the key 34 is fitted into the lobe-side
また、上記のローブ側キー溝30kは結合カムローブ30を軸方向に貫通して形成されているが、結合カムローブ30をシャフト部材20に軸方向から嵌め込むことができる形状であればよい。例えば、キー34がジャーナル部30Bのみに設けられる場合は、ローブ側キー溝30kは一方のカムローブ30Aとジャーナル部30Bとに形成されていればよい。また、ローブ側キー溝30kの位置も上記実施形態に限られず、取付孔30hの内周面であればよく、バルブリフト部31bから離れている方が好ましい。
The lobe-side keyway 30k is formed so as to penetrate the coupling cam lobe 30 in the axial direction, but may have any shape as long as the coupling cam lobe 30 can be fitted into the shaft member 20 from the axial direction. For example, when the key 34 is provided only in the journal portion 30B, the lobe-side key groove 30k may be formed in one cam lobe 30A and the journal portion 30B. Further, the position of the lobe-side key groove 30k is not limited to the above embodiment, and may be any inner peripheral surface of the mounting hole 30h, and is preferably separated from the valve lift portion 31b.
また、上記実施形態では、シャフト部材20にもシャフト側キー溝20kが設けられ、このキー溝20kにキー34が圧入されているが、シャフト部材20とキーとが一体成形され、シャフト部材20の外周面からキーが突設されていてもよい。これにより、部品点数を削減することができる。また、シャフト部材20にシャフト側キー溝20kを設ける場合よりも、シャフト部材20の強度を高く保つことができる。
In the above embodiment, the shaft member 20 is also provided with the shaft-side key groove 20k, and the key 34 is press-fitted into the key groove 20k. However, the shaft member 20 and the key are integrally formed, and the shaft member 20 A key may protrude from the outer peripheral surface. Thereby, the number of parts can be reduced. Further, the strength of the shaft member 20 can be kept higher than when the shaft-side keyway 20k is provided in the shaft member 20.
また、上記実施形態では、荒加工後に、取付孔30hを仕上げ加工し、その後でローラシャフト用孔部31mを仕上げ加工する場合を例示しているが、仕上げ加工の順番は反対でもよい。すなわち、ローラシャフト用孔部31mの位置決めを冶具を用いて精度良く行うことで、ローラシャフト用孔部31mを先に仕上げ加工し、ローラシャフト用孔部31mを基準として取付孔30hを仕上げ加工してもよい。
In the above embodiment, the case where the mounting hole 30h is finished after roughing and then the roller shaft hole 31m is finished is illustrated, but the order of finishing may be reversed. In other words, the roller shaft hole 31m is accurately positioned using a jig so that the roller shaft hole 31m is finished first, and the mounting hole 30h is finished using the roller shaft hole 31m as a reference. May be.
また、ローラ32及びローラシャフト33の表面硬化処理は高周波焼入れ焼戻し処理に限られず、他の表面焼入れ処理でもよい。また、高い表面硬度を与えることのできれば、表面焼入れ処理以外の表面硬化処理をローラ32及びローラシャフト33に施してもよい。
また、ベースカム31及びジャーナル部30Bとなる部品を鍛造品として説明しているが、ベースカム31及びジャーナル部30Bとなる部品は鍛造により成形された部品に限られず、他の手法により成形された部品であってもよい。 Further, the surface hardening process of theroller 32 and the roller shaft 33 is not limited to the induction hardening and tempering process, but may be other surface hardening process. Moreover, as long as high surface hardness can be given, surface hardening processing other than surface hardening processing may be given to the roller 32 and the roller shaft 33. FIG.
Moreover, although the parts used as thebase cam 31 and the journal part 30B are demonstrated as a forged product, the parts used as the base cam 31 and the journal part 30B are not limited to the parts formed by forging, but are parts formed by other methods. There may be.
また、ベースカム31及びジャーナル部30Bとなる部品を鍛造品として説明しているが、ベースカム31及びジャーナル部30Bとなる部品は鍛造により成形された部品に限られず、他の手法により成形された部品であってもよい。 Further, the surface hardening process of the
Moreover, although the parts used as the
また、上記実施形態では、ローラ32がベースカム31に固定されたローラシャフト33に対して回転するカムローブ30Aを説明したが、ローラ32とローラシャフト33とが固定され、ローラシャフト33がベースカム31に対して回転するカムローブであってもよい。また、ローラ32がローラシャフト33に対して回転自在であり、さらにローラシャフト33もベースカム31に対して回転自在であってもよい。
In the above embodiment, the cam lobe 30 </ b> A in which the roller 32 rotates with respect to the roller shaft 33 fixed to the base cam 31 has been described. However, the roller 32 and the roller shaft 33 are fixed, and the roller shaft 33 is fixed to the base cam 31. It may be a cam lobe that rotates. Further, the roller 32 may be rotatable with respect to the roller shaft 33, and the roller shaft 33 may also be rotatable with respect to the base cam 31.
また、ローラシャフト33の固定方法はかしめに限られず、圧入によってベースカム31に固定してもよい。結合カムローブ30の固定方法も焼きばめに限られず、圧入によって固定してもよい。
なお、シャフト部材20は、中実のパイプ形状であってもよく、オイル流路等が設けられていないものであってもよい。 The method for fixing theroller shaft 33 is not limited to caulking, and the roller shaft 33 may be fixed to the base cam 31 by press-fitting. The method of fixing the coupling cam lobe 30 is not limited to shrink fitting, and may be fixed by press fitting.
Theshaft member 20 may be a solid pipe shape or may not be provided with an oil flow path or the like.
なお、シャフト部材20は、中実のパイプ形状であってもよく、オイル流路等が設けられていないものであってもよい。 The method for fixing the
The
10 組立カムシャフト
20 シャフト部材
20k シャフト側キー溝
30 結合カムローブ
30A カムローブ
30B ジャーナル部
30h 取付孔
30k ローブ側キー溝(キー溝)
31 ベースカム
31a ベース円部
31b バルブリフト部
31h カムシャフト用孔部
31m ローラシャフト用孔部
32 ローラ
33 ローラシャフト
34 キー
40 軸受部
41 カムキャップ DESCRIPTION OFSYMBOLS 10 Assembly cam shaft 20 Shaft member 20k Shaft side keyway 30 Coupling cam lobe 30A Cam lobe 30B Journal part 30h Mounting hole 30k Robe side keyway (key groove)
31Base cam 31a Base circle part 31b Valve lift part 31h Cam shaft hole 31m Roller shaft hole 32 Roller 33 Roller shaft 34 Key 40 Bearing part 41 Cam cap
20 シャフト部材
20k シャフト側キー溝
30 結合カムローブ
30A カムローブ
30B ジャーナル部
30h 取付孔
30k ローブ側キー溝(キー溝)
31 ベースカム
31a ベース円部
31b バルブリフト部
31h カムシャフト用孔部
31m ローラシャフト用孔部
32 ローラ
33 ローラシャフト
34 キー
40 軸受部
41 カムキャップ DESCRIPTION OF
31
Claims (8)
- 内燃機関のクランクシャフトと連動して回転するシャフト部材と、
前記内燃機関の同一気筒で用いられる一対の吸気弁又は一対の排気弁を駆動する一対のカムローブ、及び、前記一対のカムローブ間に設けられるジャーナル部が一体成形され、前記シャフト部材が挿通さえる取付孔を有する結合カムローブと、を備える組立カムシャフトにおいて、
前記一対のカムローブは何れも、ベース円部及びバルブリフト部からなるベースカムと、前記バルブリフト部の先端部に設けられ前記ベースカムに対して回転自在なローラとを有するローラ付きカムローブであり、
前記シャフト部材の外周面と前記取付孔の内周面との間に、少なくとも前記ジャーナル部にて前記シャフト部材の軸方向に延びるキーが嵌め込まれる
ことを特徴する、組立カムシャフト。 A shaft member that rotates in conjunction with the crankshaft of the internal combustion engine;
A pair of cam lobes for driving a pair of intake valves or a pair of exhaust valves used in the same cylinder of the internal combustion engine, and a journal portion provided between the pair of cam lobes, and an attachment hole through which the shaft member is inserted An assembly camshaft comprising:
Each of the pair of cam lobes is a cam lobe with a roller having a base cam composed of a base circle portion and a valve lift portion, and a roller provided at a tip portion of the valve lift portion and rotatable with respect to the base cam.
An assembly camshaft characterized in that a key extending in the axial direction of the shaft member is fitted at least in the journal portion between the outer peripheral surface of the shaft member and the inner peripheral surface of the mounting hole. - 前記キーは、前記シャフト部材の外周面と前記取付孔の内周面との間において、前記シャフト部材の軸心を挟んで前記ローラと対向する位置に設けられる
ことを特徴とする、請求項1記載の組立カムシャフト。 The key is provided between the outer peripheral surface of the shaft member and the inner peripheral surface of the mounting hole at a position facing the roller across the axis of the shaft member. Assembly camshaft as described. - 前記シャフト部材は、前記シャフト部材の軸方向に沿って形成されたシャフト側キー溝を有し、
前記結合カムローブは、前記取付孔の内周面に、前記結合カムローブの軸方向全長に亘って形成されたローブ側キー溝を有し、
前記キーは、前記シャフト側キー溝及び前記ローブ側キー溝に嵌め込まれる
ことを特徴とする、請求項1記載の組立カムシャフト。 The shaft member has a shaft-side keyway formed along the axial direction of the shaft member;
The coupling cam lobe has a lobe-side key groove formed on the inner peripheral surface of the mounting hole over the entire axial length of the coupling cam lobe,
The assembly camshaft according to claim 1, wherein the key is fitted into the shaft side keyway and the lobe side keyway. - 前記ローブ側キー溝の深さは、前記キーが前記シャフト部材に嵌め込まれた状態で前記シャフト部材の外周面から突出している量よりも大きく設定される
ことを特徴とする、請求項3記載の組立カムシャフト。 The depth of the lobe-side key groove is set to be larger than an amount protruding from an outer peripheral surface of the shaft member in a state where the key is fitted into the shaft member. Assembly camshaft. - 前記シャフト部材は、前記シャフト部材の軸方向に沿って形成されたシャフト側キー溝を有し、
前記結合カムローブは、前記取付孔の内周面に、前記結合カムローブの軸方向全長に亘って形成されたローブ側キー溝を有し、
前記キーは、前記シャフト側キー溝及び前記ローブ側キー溝に嵌め込まれる
ことを特徴とする、請求項2記載の組立カムシャフト。 The shaft member has a shaft-side keyway formed along the axial direction of the shaft member;
The coupling cam lobe has a lobe-side key groove formed on the inner peripheral surface of the mounting hole over the entire axial length of the coupling cam lobe,
The assembly camshaft according to claim 2, wherein the key is fitted into the shaft side keyway and the lobe side keyway. - 前記ローブ側キー溝の深さは、前記キーが前記シャフト部材に嵌め込まれた状態で前記シャフト部材の外周面から突出している量よりも大きく設定される
ことを特徴とする、請求項5記載の組立カムシャフト。 The depth of the lobe-side key groove is set to be larger than an amount protruding from an outer peripheral surface of the shaft member in a state where the key is fitted into the shaft member. Assembly camshaft. - 前記結合カムローブは、前記取付孔の内周面に、前記結合カムローブの軸方向に沿って形成されたローブ側キー溝を有し、
前記キーは、前記シャフト部材と一体成形され、前記ローブ側キー溝に嵌め込まれる
ことを特徴とする、請求項1記載の組立カムシャフト。 The coupling cam lobe has a lobe-side key groove formed along the axial direction of the coupling cam lobe on the inner peripheral surface of the mounting hole,
The assembly camshaft according to claim 1, wherein the key is integrally formed with the shaft member and is fitted into the lobe-side keyway. - 前記結合カムローブは、前記取付孔の内周面に、前記結合カムローブの軸方向に沿って形成されたローブ側キー溝を有し、
前記キーは、前記シャフト部材と一体成形され、前記ローブ側キー溝に嵌め込まれる
ことを特徴とする、請求項2記載の組立カムシャフト。
The coupling cam lobe has a lobe-side key groove formed along the axial direction of the coupling cam lobe on the inner peripheral surface of the mounting hole,
The assembly camshaft according to claim 2, wherein the key is integrally formed with the shaft member and is fitted into the lobe-side keyway.
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JP2015529512A JP6037017B2 (en) | 2013-07-31 | 2014-07-17 | Assembly camshaft |
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2020014368A (en) * | 2018-07-20 | 2020-01-23 | 株式会社一宮電機 | Brushless motor and manufacturing method thereof |
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JPS6157106U (en) * | 1984-09-20 | 1986-04-17 | ||
JPS6365806U (en) * | 1986-10-20 | 1988-04-30 | ||
JP2004036650A (en) * | 2002-06-28 | 2004-02-05 | Honda Motor Co Ltd | Camshaft |
JP2005090345A (en) * | 2003-09-17 | 2005-04-07 | Toyota Motor Corp | Support structure of cam shaft for internal combustion engine |
JP2006200440A (en) * | 2005-01-20 | 2006-08-03 | Otics Corp | Cam shaft |
-
2014
- 2014-07-17 JP JP2015529512A patent/JP6037017B2/en active Active
- 2014-07-17 WO PCT/JP2014/068988 patent/WO2015016074A1/en active Application Filing
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JPS6157106U (en) * | 1984-09-20 | 1986-04-17 | ||
JPS6365806U (en) * | 1986-10-20 | 1988-04-30 | ||
JP2004036650A (en) * | 2002-06-28 | 2004-02-05 | Honda Motor Co Ltd | Camshaft |
JP2005090345A (en) * | 2003-09-17 | 2005-04-07 | Toyota Motor Corp | Support structure of cam shaft for internal combustion engine |
JP2006200440A (en) * | 2005-01-20 | 2006-08-03 | Otics Corp | Cam shaft |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2020014368A (en) * | 2018-07-20 | 2020-01-23 | 株式会社一宮電機 | Brushless motor and manufacturing method thereof |
JP7149497B2 (en) | 2018-07-20 | 2022-10-07 | 株式会社一宮電機 | BRUSHLESS MOTOR AND MANUFACTURING METHOD OF BRUSHLESS MOTOR |
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