WO2016166932A1 - コンロッド及びその製造方法 - Google Patents
コンロッド及びその製造方法 Download PDFInfo
- Publication number
- WO2016166932A1 WO2016166932A1 PCT/JP2016/001306 JP2016001306W WO2016166932A1 WO 2016166932 A1 WO2016166932 A1 WO 2016166932A1 JP 2016001306 W JP2016001306 W JP 2016001306W WO 2016166932 A1 WO2016166932 A1 WO 2016166932A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- rib
- connecting rod
- hardness
- forging
- pair
- Prior art date
Links
Images
Classifications
-
- 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
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C7/00—Connecting-rods or like links pivoted at both ends; Construction of connecting-rod heads
- F16C7/02—Constructions of connecting-rods with constant length
- F16C7/023—Constructions of connecting-rods with constant length for piston engines, pumps or the like
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D37/00—Tools as parts of machines covered by this subclass
- B21D37/16—Heating or cooling
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D53/00—Making other particular articles
- B21D53/84—Making other particular articles other parts for engines, e.g. connecting-rods
-
- 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
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C9/00—Bearings for crankshafts or connecting-rods; Attachment of connecting-rods
- F16C9/04—Connecting-rod bearings; Attachments thereof
- F16C9/045—Connecting-rod bearings; Attachments thereof the bearing cap of the connecting rod being split by fracturing
-
- 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
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C2360/00—Engines or pumps
- F16C2360/22—Internal combustion engines
-
- 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
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J1/00—Pistons; Trunk pistons; Plungers
- F16J1/10—Connection to driving members
- F16J1/14—Connection to driving members with connecting-rods, i.e. pivotal connections
- F16J1/16—Connection to driving members with connecting-rods, i.e. pivotal connections with gudgeon-pin; Gudgeon-pins
Definitions
- the present invention relates to a connecting rod that connects a crankshaft and a piston of an internal combustion engine, and more particularly to a connecting rod that locally increases the strength of a flange that connects a large end and a small end, and a method for manufacturing the connecting rod.
- the flange portion is hot in a substantially H-shaped cross section including a belt-shaped web portion and four rib portions erected from both widthwise ends of both surfaces.
- a hot forging process for forging and an open forging die configured to cover the entire surface of the rib part and other parts of the web part while having an open part that opens only the outer side surfaces at both ends in the width direction of the web part
- the upper holding die is provided with an upper molding die for forming the buttock
- the lower holding die is provided with a pair of left and right side molding dies, for the large end, in addition to the lower molding die for molding the buttock.
- An end molding die for a small end is provided, and the upper holding die is guided by a male taper surface formed on the outer surface of the side molding die and the end molding die and a female taper surface formed on the upper holding.
- a connecting rod excellent in buckling strength and fatigue strength a low carbon boron steel is formed into a connecting rod shape by hot forging and then quenched, and the rib portion of the obtained forged coarse material is aligned along the longitudinal direction.
- the rib is plastically deformed by 0.2 mm or more in the thickness direction (rib height direction), work hardened, and further shot peened
- a method is known in which fatigue strength is improved by applying (Patent Document 3).
- JP 2005-14079 A Japanese Patent No. 5268715 JP-A-9-196044
- an object of the present invention is to provide a connecting rod that can be manufactured without causing an increase in cost, and whose buttock is effectively strengthened, and a manufacturing method thereof.
- one aspect of the present invention is a connecting rod (1) having a large end portion (2), a small end portion (3), and a hook portion (4) having a substantially H-shaped cross section connecting them.
- the flange portion includes a pair of rib portions (21, 21) extending in parallel to each other, and a web portion having both ends connected to substantially the center in the height direction of the pair of rib portions ( 22), and the rib portion has a rib root portion (23) located at the center in the height direction and a pair of rib tip portions (24) located at both ends in the height direction in the cross section of the flange portion.
- the hardness of the rib tip portion is 40 HV or more higher than the hardness of the web portion
- the hardness of the rib base portion is 30 HV or more higher than the hardness of the web portion.
- the rib tip portion refers to a portion occupying a quarter of the height of the rib portion at both ends of the rib portion, and the rib root portion does not include the rib tip portion, and the height direction of the rib portion.
- the part which occupies 1/2 of the height of a rib part in the center of is shown.
- tip part, and a rib base part is not the value measured on each surface, but the cut surface of the collar part cut
- the rib tip portion having the largest contribution to the increase in buckling strength is 40 HV or more higher than the hardness of the web portion, and the rib root portion having the next largest contribution to the increase in buckling strength is provided. Since the hardness is 30 HV or more higher than the hardness of the web portion, the heel portion is effectively increased in strength. Further, since it is only necessary to process the rib tip portion so as to increase the hardness, the connecting rod can be manufactured without requiring a large forging load and without using a special mold.
- the hardness of the rib tip portion may be higher than the hardness of the rib base portion.
- the rib tip portion having the largest contribution to the increase in buckling strength has the highest hardness, so that the heel portion is effectively strengthened. Further, since it is only necessary to process the tip end of the most protruding rib so as to have the highest hardness, the connecting rod can be manufactured without requiring a large forging load or a special mold.
- one embodiment of the present invention includes a large end portion, a small end portion, a pair of rib portions extending in parallel with each other in a cross section, and a height direction of the pair of rib portions.
- a method for manufacturing a connecting rod having a web portion connected at both ends at a substantially center and having a substantially H-shaped cross section and a flange portion connecting the large end portion and the small end portion.
- the first step of air-cooling the rough shape, and sandwiching the air-cooled rough shape from above and below by a lower mold and an upper mold, and the rib in the cross section The hardness of the pair of rib tip portions located at both ends in the height direction of the portion is 40 HV or more higher than the hardness of the web portion, and the rib root portion located at the center in the height direction of the rib portion in the cross section The hardness is higher than the hardness of the web part by 30HV or more.
- a second step of forming is
- the connecting rod by forging the rough shape material using only the lower mold and the upper mold, it is possible to manufacture a connecting rod having a heel portion that is effectively strengthened without complicating the mold. Moreover, since it is only necessary to forge the rough shape so as to increase the hardness of the rib tip portion, the connecting rod can be manufactured without requiring a large forging load.
- the rough shaped material may be cold forged.
- many dislocations can be introduced into the buttock tissue, and the strength of the buttock can be improved by strengthening the dislocation.
- the rib height of the connecting rod after forging is smaller than the rib height of the rough shape member, and after forging as compared with the rib thickness of the rough shape member.
- a rib thickness of the connecting rod is large, a rib interval of the connecting rod after forging is larger than a rib interval of the rough shaped member, and a flange portion of the connecting rod after forging is larger than a width of the flange portion of the rough shaped member.
- the rough shaped material may be cold forged using the lower mold and the upper mold having a shape such that the width of the rough mold is increased.
- the second step when the forging load is applied using the lower mold having a side wall extending upward from the center in the height direction of the pair of rib portions after forging, The center portion of the pair of rib portions of the rough shape member is restrained from the outside by the lower mold, and when a forging load is applied, the outer surface of the lower portion of the pair of rib portions of the rough shape member and the The lower mold, such that a gap remains between the inner surface of the lower mold, and a gap remains between the outer surface of the upper portion of the pair of rib portions of the rough profile and the inner surface of the upper mold;
- the rough shape material may be cold forged using the upper mold.
- forging can be performed without generating burrs, and forging can be performed by semi-sealing upsetting with a relatively small forging load.
- the number of manufacturing steps can be reduced, the equipment can be downsized, and the manufacturing cost of the connecting rod having the above-described configuration can be reduced.
- dislocations introduced by forging can be fixed, and work hardening can be manifested in the buttock as a stable enemy.
- FIG. Front view of connecting rod according to the present invention II-II sectional view in FIG. Explanatory drawing of the manufacturing method of the connecting rod shown in FIG. (A) Before cold forging, (B) Cross section of the collar after cold forging Explanatory drawing showing the definition of the dimensions of the buttocks
- the connecting rod 1 connects a large end 2 connected to a crankshaft (not shown), a small end 3 connected to a piston (not shown), and the large end 2 and the small end 3. It has a collar part 4.
- the large end portion 2 forms an annular bearing that surrounds the crankpin of the crankshaft, and defines a crankpin hole 2a having a circular cross section.
- the small end portion 3 forms an annular bearing that surrounds the piston pin, and defines a piston pin hole 3a having a circular cross section.
- the axis 2X of the large end 2 and the axis 3X of the small end 3 are parallel to each other.
- the connecting rod 1 is fastened by a pair of bolts 6 to a connecting rod body 5 that forms a half portion of the small end portion 3, the flange portion 4 and the large end portion 2 on the flange portion 4 side, and a half portion of the connecting rod body 5.
- the cap 7 forms the remaining half of the end 2.
- FIG. 2 shows a cross section of the intermediate portion in the longitudinal direction of the collar portion 4.
- the flange 4 passes through the center of the large end 2 (the midpoint of the axis 2X) and the center of the small end 3 (the midpoint of the axis 3X), and the respective axes 2X, This is a columnar portion extending on the first virtual plane 11 orthogonal to 3X.
- the flange portion 4 has a predetermined width W in the direction along the first virtual plane 11 so that it does not buckle even if it receives a compressive load in the combustion stroke, and the axis 2X of the large end portion 2 and the small end portion 3.
- the width W of the flange portion 4 is substantially constant in the middle portion of the flange portion 4 in the longitudinal direction, and gradually increases toward the large end portion 2 and the small end portion 3 in the vicinity of the large end portion 2 and the small end portion 3. It is getting bigger.
- the thickness (H) of the flange portion 4 is substantially the same as the thicknesses of the large end portion 2 and the small end portion 3 and is substantially constant over the entire length of the flange portion 4 in the longitudinal direction.
- the collar part 4 is made thin in the width direction center part for weight reduction, and is exhibiting the cross-sectional substantially H shape.
- the collar portion 4 has a generally vertically symmetrical shape around the first virtual plane 11. Moreover, the collar part 4 is made into the shape of substantially left-right symmetry centering on the 2nd virtual plane 12.
- FIG. The flange portion 4 has a pair of parallel rib portions 21 and 21 extending in parallel to the second virtual plane 12 at both left and right ends, and a pair of rib portions 21 extending on the first virtual plane 11. It is comprised from the web part 22 which both ends connect to the center of 21 height directions. Thereby, the cross section of the collar part 4 becomes a substantially H shape.
- the rib portion 21 is the thickest in the middle portion in the height direction (the dimension in the left-right direction is large), and gradually becomes thinner as it approaches the upper end and the lower end. Both corners of the tip (upper end and lower end) of the rib portion 21 are curved surfaces.
- the inner surfaces 21i, 21i of the pair of rib portions 21, 21 are inclined surfaces that approach each other as they approach the center in the height direction.
- a vertical surface 21v that is substantially orthogonal to the first virtual plane 11 is formed at the center in the height direction.
- the rib part 21 is formed in the substantially same thickness over the full length of the collar part 4 (refer FIG. 1). As described above, since the flange portion 4 has a substantially constant thickness, the height H of the rib portion 21 is substantially the same over the entire length of the flange portion 4.
- the upper surface and the lower surface of the web portion 22 are parallel planes 22f at the intermediate portion in the width direction, and are curved surfaces 22c that are gently connected to the inner surface 21i of the rib portion 21 at the left and right ends. That is, the web portion 22 has a constant thickness T in the intermediate portion in the width direction, and gradually increases as the left and right rib portions 21 are approached.
- the web portion 22 and the rib portion 21 are connected to each other via the curved surface 22c, and the boundary between the two is not uniquely determined.
- the inclined surface that forms the inner surface 21i of the rib portion 21 is the first.
- An extension line extending to one virtual plane 11 is defined as a boundary between the two.
- the rib root part 23 the part located in the both ends (upper end and lower end) of a height direction is called the rib root part 23, and the part located in the both ends (upper end and lower end) of a height direction is a rib front-end
- the rib tip portion 24 refers to a portion that occupies a quarter of the height H of the rib portion 21 at both ends of the rib portion 21, and the rib root portion 23 refers to the rib tip portion 24. It is defined not to include a portion that occupies a half of the height H of the rib portion 21 at the center in the height direction of the rib portion 21.
- ⁇ 4 having such a shape has different hardness (Vickers hardness (HV), the same applies hereinafter) for each part.
- Vickers hardness (HV) the same applies hereinafter
- the hardness of the rib tip 24 is higher than the hardness of the web 22 by 40 HV or more.
- the hardness of the rib base portion 23 is higher by 30 HV or more than the hardness of the web portion 22.
- the hardness of the rib tip portion 24 is higher than the hardness of the rib root portion 23.
- tip part 24, and the rib base part 23 is not the value measured on each surface, but the collar part 4 cut
- the hardness of the rib tip portion 24 is a value measured at the center in the width direction at a position of 1.5 mm from the tip surface of the rib tip portion 24 toward the first virtual plane 11 side.
- the hardness of the rib root portion 23 is a value measured at the center in the width direction of the rib root portion 23 at a position one-sixth of the height H of the rib portion 21 from the first virtual plane 11.
- the hardness is measured according to the Vickers hardness test method defined in JIS Z 2244.
- the hardness of the rib tip 24 has the highest value among the four measurement points. What is necessary is just to be higher than the hardness of the measurement point having the lowest value among the four measurement points of the rib root portion 23 by 40 HV or more with respect to the hardness of 22.
- the buckling strength is proportional to the proof stress (yield stress) of the material from Rankine's equation and Tetmeier's equation.
- yield stress proof stress
- Tetmeier's equation the proof stress and hardness of the material are approximately proportional. That is, the buckling strength is substantially proportional to the hardness of the material, and the buckling strength increases as the hardness of the flange portion 4 increases.
- the generated stress at the rib tip portion 24 is about 1.6 times higher than the generated stress at the web portion 22, and the rib root portion It was confirmed that the generated stress of 23 was about 1.3 times higher than the generated stress of the web portion 22. This means that in order to increase the buckling strength of the flange portion 4, it is effective to reinforce the rib tip portion 24 where the generated stress is high.
- the hardness of the rib tip portion 24 having the largest contribution to the increase in buckling strength is 40 HV or more higher than the hardness of the web portion 22, and the buckling strength is increased. Since the hardness of the rib base portion 23 having the next largest contribution to is higher than the hardness of the web portion 30 by 30 HV or more, the flange portion 4 is effectively strengthened against buckling. Moreover, since the hardness of the rib front-end
- FIG. 3 is a graph showing manufacturing conditions of the connecting rod 1 with time on the horizontal axis and temperature on the vertical axis.
- the connecting rod 1 was manufactured using V non-tempered steel (0.35C-0.7Si-0.7Mn-0.08V) used as a material for connecting rods 1 in mass production.
- V non-tempered steel (0.35C-0.7Si-0.7Mn-0.08V) used as a material for connecting rods 1 in mass production.
- the material of the connecting rod 1 is not limited to this, and may be any metal that exhibits work hardening represented by carbon steel.
- the raw material is first heated to a solution temperature of 1230 ° C., subjected to hot forging to form a rough shaped member 51 (preform or intermediate product) of the connecting rod 1, and then the rough shaped member 51.
- the air is cooled (natural cooling) and the temperature is lowered to room temperature. This step is performed in order to introduce many dislocations in the ferrite structure by applying cold forging described later after adjusting the ferrite-pearlite mixed structure with the aim of improving the strength by strengthening the dislocation.
- the rough shaped member 51 of the connecting rod 1 is processed by cold forging using a die 30 described later at room temperature.
- a work hardening phenomenon occurs in which the yield strength of the material increases so that the dislocation density in ferrite increases as the processing rate increases.
- the connecting rod 1 cold-forged into the above shape is heated to 400 ° C. in an atmospheric furnace, held for 15 minutes, and then annealed by air cooling.
- the dislocations introduced by cold forging are unstable due to the presence of many movable dislocations, so dislocation strengthening is insufficient in the cold forging state.
- This is done for the purpose of fixing. That is, C, which is an interstitial solid solution element in steel, is diffused into the dislocations by heat treatment to fix the dislocations. Thereby, work hardening appears stably in the collar part 4.
- the annealing temperature is not limited to 400 ° C, but is preferably 200 ° C to 600 ° C, more preferably 250 ° C to 500 ° C, and most preferably 400 ° C.
- FIG. 4A shows the state of the connecting rod 1 before applying the forging load (before cold forging), that is, the state of the rough shaped member 51 and the mold 30 of the connecting rod 1
- FIG. 4B shows the forging load.
- die 30 after adding (after cold forging) is shown.
- the rough shaped member 51 of the connecting rod 1 has a shape close to that of the connecting rod 1 after cold forging, and each part will be described using the same name and reference sign as the connecting rod 1.
- the mold 30 includes a lower mold 31 and an upper mold 32.
- the mold 30 is for cold forging only the flange portion 4 of the rough shaped member 51 of the connecting rod 1.
- cold forging is applied to the large end 2 and the small end 3
- workability in a subsequent processing step is deteriorated, so that the large end 2 and the small end 3 are not cold forged.
- Concave surfaces corresponding to the shape of the flange 4 of the connecting rod 1 after cold forging are formed on the upper surface of the lower mold 31 and the lower surface of the upper mold 32.
- the lower molding die 31 and the upper molding die 32 are substantially symmetrical in the vertical direction, but the side wall portion facing the vertical surface 21v of the rib portion 21 that sandwiches the flange portion 4 from the left and right is formed in the lower molding die 31. ing. That is, the amount of upward protrusion of the side wall 31s of the lower mold 31 is larger than the amount of downward protrusion of the side wall 32s of the upper mold 32.
- the vertical surface 21v and the side wall 31s of the lower mold 31 may be slightly inclined in consideration of die cutting.
- the rough shaped material 51 of the connecting rod 1 is set on the lower forming die 31, and the rough shaped material 51 of the connecting rod 1 is sandwiched from above and below by the lower forming die 31 and the upper forming die 32.
- the state shown in FIG. In the state where the cold forging shown in FIG. 4B is completed, the upper end of the side wall 31s of the lower mold 31 is located above the upper end of the vertical surface 21v of the rib portion 21, and the left and right sides of the lower mold 31 are left and right.
- the side walls 31s and 31s of the upper side and the side walls 32s and 32s of the upper mold 32 on the left and right sides are in contact with each other. Further, the central vertical surface 21v of the outer surface 21o of the rib portion 21 is in contact with the side wall 31s of the lower molding die 31, but the other parts are in contact with the side walls 31s and 32s of the lower molding die 31 and the upper molding die 32. There is no contact. That is, when a forging load is applied, the central portion of the rib portion 21 (the portion forming the vertical surface 21v) is restrained from the outside by the lower mold 31 and plastic deformation to the side is restricted. The lower part and the upper part of the part 21 are plastically deformed without being constrained from the outside.
- the lower molding die 31 and the upper molding die 32 have a rib height of the connecting rod 1 after the cold forging in FIG. 4B compared to the rib height h 1 of the rough shaped member 51 of the connecting rod 1 in FIG. h 2 is small, and the rib thickness t 2 of the connecting rod 1 after cold forging in FIG. 4B is larger than the rib thickness t 1 of the rough shaped member 51 of the connecting rod 1 in FIG. 4 as compared to rib spacing d 1 of the coarse profile 51 of the connecting rod 1 4 (B) rib spacing d 2 is greater of the connecting rod 1 after the cold forging of the (a), FIG. 4 of the connecting rod 1 (a) than the width W 1 of the rod portion 4 of Sokatachizai 51 width W 2 of FIG.
- the thickness T 2 of the web portion 22 of the connecting rod 1 after cold forging in FIG. 4B is compared with the thickness T 1 of the web portion 22 of the rough shaped member 51 of the connecting rod 1 in FIG. Slightly smaller but almost unchanged.
- the thickness T 2 of the web portion 22 shown in FIG. 4 (B) is slightly larger than the thickness T 1 of the web portion 22 shown in FIG. 4 (A) It may be a shape.
- FIG. 5 schematically shows the flange 4 of the connecting rod 1.
- the rib height h is a protruding amount of the rib portion 21 upward and downward with respect to the intermediate portion having a constant thickness of the web portion 22 (height relative to an extension line of the plane 22f in FIG. 2).
- the rib thickness t is a width dimension of the rib portion 21 at a position that is 1/2 of the rib height h.
- the rib interval d is a distance between the inner surfaces of the pair of rib portions 21 and 21 at a position that is 1/2 of the rib height h.
- the width W of the collar part 4 is the maximum width of the collar part 4 (same as the width W shown in FIG. 2).
- the thickness T of the web portion 22 is the minimum thickness of the web portion 22 (same as the thickness T of the constant thickness portion formed in the intermediate portion in the width direction shown in FIG. 2).
- the flange portion 4 that expresses the hardness of the above distribution with a relatively small forging load, that is, the rib tip portion 24. It is possible to mold the collar portion 4 in which the hardness (working rate) of the steel plate has been increased significantly. Further, since the mold 30 has a simple configuration including the lower mold 31 and the upper mold 32, the mold manufacturing cost can be reduced.
- cold forging can be performed without generating burrs, and cold forging can be performed by semi-sealing upsetting with a relatively small forging load, and plastic deformation can be preferentially performed in the order of the rib tip portion 24 and the rib root portion 23. it can.
- Table 1 below shows the hardness of each part of the collar part 4, the difference in hardness between the parts, the forging load, the buckling strength, and the strength ratio for Examples 1 to 4 and Comparative Examples 1 to 3. .
- the rough shaped member 51 of the connecting rod 1 that has been hot forged in the same procedure using the same material as in the above embodiment is used.
- the connecting rod 1 was manufactured by using the same mold 30 as described above and varying the forging load according to the above procedure.
- Comparative Example 1 corresponds to the method described in Patent Document 1, and cold forging is performed so as to increase the strength of the flange 4 over the entire cross section.
- Comparative Example 2 corresponds to the method described in Patent Document 3, and cold forging is performed by applying a load only to the rib tip surface. Comparative Example 3 was formed by only hot forging without performing cold forging.
- the hardness of the rib tip portion 24 is 40 to 70 HV higher than the hardness of the web portion 22, and the hardness of the rib root portion 23 is 30 to 40 HV higher than the hardness of the web portion 22.
- the forging load is 180 to 240 t
- the buckling strength is 800 to 900 MPa.
- the buckling strength ratio of Examples 1 to 4 to Comparative Example 3 is 1.23 to 1.42.
- Comparative Example 2 the forging load is 150 t smaller than those in Examples 1 to 4, and the hardness of the rib tip portion 24 is 70 HV higher than the hardness of the web portion 22. Is only 20 HV higher than the hardness of the web portion 22.
- the buckling strength is 750 MPa lower than those in Examples 1 to 4, and the strength ratio with respect to Comparative Example 3 is 1.15.
- Comparative Example 1 there is no difference in hardness between the parts because the whole of the heel part 4 is increased in strength.
- the buckling strength is the highest (same as in Example 2) 920 MPa, and the strength ratio with respect to Comparative Example 3 is 1.42, which is much higher than in Examples 1 to 4. A large forging load of 650 t is required.
- the buckling strength of Comparative Example 1 is the same as Example 2 in which the forging load is only 240 t. In other words, in Examples 1 to 4, the flange portion 4 is effectively strengthened with a smaller forging load than in Comparative Example 1.
- the present invention is not limited to the above-described embodiment, and can be widely modified.
- the temperature is lowered to room temperature by air cooling, and cold forging is performed at room temperature.
- warm forging may be performed after the temperature is lowered to about 400 ° C. by air cooling.
- the temperature is lowered to room temperature by air cooling, and then the rough shape 51 of the connecting rod 1 is heated again to about 400 ° C. to perform warm forging. May be.
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
- Forging (AREA)
Abstract
Description
2 大端部
3 小端部
4 桿部
21 リブ部
22 ウェブ部
23 リブ根元部
24 リブ先端部
30 金型
31 下成形型
32 上成形型
32s 側壁
51 コンロッド1の粗形材
W 桿部4の幅
d リブ間隔
h リブ高さ
t リブ厚さ
Claims (7)
- 大端部と小端部とこれらを繋ぐ断面略H形の桿部とを有するコンロッドであって、
前記桿部は、断面において、互いに平行に延在する一対のリブ部と、当該一対のリブ部の高さ方向の略中央に両端が接続するウェブ部とを有し、
前記リブ部は、前記桿部の断面において、高さ方向の中央に位置するリブ根元部と、高さ方向の両端に位置する一対のリブ先端部とからなり、
前記リブ先端部の硬さが前記ウェブ部の硬さに対して40HV以上高く、前記リブ根元部の硬さが前記ウェブ部の硬さに対して30HV以上高いことを特徴とするコンロッド。 - 前記リブ先端部の硬さが前記リブ根元部の硬さよりも高いことを特徴とする請求項1に記載のコンロッド。
- 大端部と、小端部と、断面において互いに平行に延在する一対のリブ部及び当該一対のリブ部の高さ方向の略中央に両端が接続するウェブ部を有し、断面略H形を呈して前記大端部及び前記小端部を繋ぐ桿部とを有するコンロッドの製造方法であって、
素材鋼を熱間鍛造し、前記コンロッドの粗形材を成形した後、当該粗形材を空冷する第1工程と、
前記粗形材を下成形型と上成形型とにより上下から挟み込み、断面において前記リブ部の高さ方向の両端に位置する一対のリブ先端部の硬さが前記ウェブ部の硬さに対して40HV以上高く、断面において前記リブ部の高さ方向の中央に位置するリブ根元部の硬さが前記ウェブ部の硬さに対して30HV以上高くなるように鍛造する第2工程と
を含むことを特徴とするコンロッドの製造方法。 - 前記第2工程では、前記粗形材を冷間鍛造することを特徴とする請求項3に記載のコンロッドの製造方法。
- 前記第2工程では、前記粗形材のリブ高さに比べて鍛造後の前記コンロッドのリブ高さが小さく、前記粗形材のリブ厚さに比べて鍛造後の前記コンロッドのリブ厚さが大きく、前記粗形材のリブ間隔に比べて鍛造後の前記コンロッドのリブ間隔が大きく、前記粗形材の桿部の幅に比べて鍛造後の前記コンロッドの桿部の幅が大きくなるような形状の前記下成形型及び前記上成形型を用いて、前記粗形材を冷間鍛造することを特徴とする請求項4に記載のコンロッドの製造方法。
- 前記第2工程では、鍛造後に前記一対のリブ部の高さ方向の中央よりも上方へ延出する側壁を有する前記下成形型を用い、鍛造荷重を加えた時に前記粗形材の前記一対のリブ部の中央部を前記下成形型により外方から拘束すると共に、鍛造荷重を加えた時に、前記粗形材の前記一対のリブ部の下側部分の外面と前記下成形型の内面との間に間隙が残り、かつ前記粗形材の前記一対のリブ部の上側部分の外面と前記上成形型の内面との間に間隙が残るような前記下成形型及び前記上成形型を用いて、前記粗形材を冷間鍛造することを特徴とする請求項5に記載のコンロッドの製造方法。
- 前記第2工程の後、前記コンロッドを加熱した後に空冷する焼鈍しを行う第3工程を更に含むことを特徴とする請求項3~請求項6のいずれかに記載のコンロッドの製造方法。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE112016001755.3T DE112016001755T5 (de) | 2015-04-16 | 2016-03-09 | Pleuelstange und deren herstellungsverfahren |
JP2017512189A JP6387456B2 (ja) | 2015-04-16 | 2016-03-09 | コンロッドの製造方法 |
CN201680022009.XA CN107532636B (zh) | 2015-04-16 | 2016-03-09 | 制造连杆的方法 |
US15/564,034 US10161439B2 (en) | 2015-04-16 | 2016-03-09 | Connecting rod and manufacturing method thereof |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2015083861 | 2015-04-16 | ||
JP2015-083861 | 2015-04-16 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2016166932A1 true WO2016166932A1 (ja) | 2016-10-20 |
Family
ID=57126755
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2016/001306 WO2016166932A1 (ja) | 2015-04-16 | 2016-03-09 | コンロッド及びその製造方法 |
Country Status (5)
Country | Link |
---|---|
US (1) | US10161439B2 (ja) |
JP (1) | JP6387456B2 (ja) |
CN (1) | CN107532636B (ja) |
DE (1) | DE112016001755T5 (ja) |
WO (1) | WO2016166932A1 (ja) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10578150B2 (en) * | 2018-07-24 | 2020-03-03 | GM Global Technology Operations LLC | Combustion engine connecting rod |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004308887A (ja) * | 2003-02-19 | 2004-11-04 | Nissan Motor Co Ltd | 高強度コンロッドおよびその製造方法 |
JP2005121056A (ja) * | 2003-10-14 | 2005-05-12 | Toyota Motor Corp | コンロッド、コンロッドの製造方法及び製造装置 |
JP2007146233A (ja) * | 2005-11-28 | 2007-06-14 | Nippon Steel Corp | 鋼製自動車用構造部品の製造方法 |
JP2011084767A (ja) * | 2009-10-14 | 2011-04-28 | Honda Motor Co Ltd | クラッキングコンロッドの製造方法 |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS52124406A (en) | 1976-04-14 | 1977-10-19 | Hitachi Ltd | Connecting rod |
JPS5790921U (ja) | 1980-11-25 | 1982-06-04 | ||
JPS57115937U (ja) | 1981-01-12 | 1982-07-17 | ||
JPH09196044A (ja) | 1996-01-22 | 1997-07-29 | Nissan Motor Co Ltd | コンロッドの製造方法 |
EP1450056B1 (en) | 2003-02-19 | 2017-06-07 | Nissan Motor Co., Ltd. | High-strength connecting rod and method of producing same |
EP1605071B1 (en) * | 2003-03-18 | 2008-10-15 | Sumitomo Metal Industries, Ltd. | Non-quenched/tempered connecting rod and method of producing the same |
JP2005014079A (ja) | 2003-06-30 | 2005-01-20 | Aichi Steel Works Ltd | 部分冷間強化コンロッドの製造方法 |
EP1801432A3 (en) * | 2005-12-20 | 2009-07-22 | Yamaha Hatsudoki Kabushiki Kaisha | Connecting rod and method of producing the same |
JP5268715B2 (ja) | 2009-03-05 | 2013-08-21 | 株式会社三條機械製作所 | コンロッドの製造方法及びこれに用いるコイニング型装置 |
JP2010261473A (ja) * | 2009-04-30 | 2010-11-18 | Yamaha Motor Co Ltd | 内燃機関用摺動部品、内燃機関、輸送機器および内燃機関用摺動部品の製造方法 |
-
2016
- 2016-03-09 JP JP2017512189A patent/JP6387456B2/ja not_active Expired - Fee Related
- 2016-03-09 US US15/564,034 patent/US10161439B2/en active Active
- 2016-03-09 CN CN201680022009.XA patent/CN107532636B/zh active Active
- 2016-03-09 DE DE112016001755.3T patent/DE112016001755T5/de not_active Ceased
- 2016-03-09 WO PCT/JP2016/001306 patent/WO2016166932A1/ja active Application Filing
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004308887A (ja) * | 2003-02-19 | 2004-11-04 | Nissan Motor Co Ltd | 高強度コンロッドおよびその製造方法 |
JP2005121056A (ja) * | 2003-10-14 | 2005-05-12 | Toyota Motor Corp | コンロッド、コンロッドの製造方法及び製造装置 |
JP2007146233A (ja) * | 2005-11-28 | 2007-06-14 | Nippon Steel Corp | 鋼製自動車用構造部品の製造方法 |
JP2011084767A (ja) * | 2009-10-14 | 2011-04-28 | Honda Motor Co Ltd | クラッキングコンロッドの製造方法 |
Also Published As
Publication number | Publication date |
---|---|
DE112016001755T5 (de) | 2018-01-18 |
US20180087562A1 (en) | 2018-03-29 |
CN107532636B (zh) | 2020-01-17 |
JP6387456B2 (ja) | 2018-09-05 |
JPWO2016166932A1 (ja) | 2017-09-21 |
CN107532636A (zh) | 2018-01-02 |
US10161439B2 (en) | 2018-12-25 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US9550221B2 (en) | Press forming method for steel plate | |
JP6091046B2 (ja) | アルミ合金ボルトの製造方法及びアルミ合金ボルト | |
JP6245369B2 (ja) | 鍛造クランク軸の製造方法 | |
US20150128416A1 (en) | Method of manufacturing die forged crankshaft | |
KR20140022827A (ko) | 포펫 밸브의 페이스부의 형성 방법 및 이 형성 방법에 의한 페이스부를 가지는 포펫 밸브 | |
US20160250679A1 (en) | Method for producing a forged crankshaft | |
JPWO2016152933A1 (ja) | 鍛造クランク軸の製造方法 | |
RU2692353C1 (ru) | Способ производства штампованных изделий и производственная линия для них | |
US10413965B2 (en) | Method for producing forged crankshaft | |
JPWO2016147674A1 (ja) | 鍛造クランク軸の製造方法 | |
JP6387456B2 (ja) | コンロッドの製造方法 | |
KR20140048152A (ko) | 피스톤 또는 피스톤 샤프트를 제조하기 위한 단조 방법 | |
US11192162B2 (en) | Method and device for forming a semi-finished product | |
JP6795812B2 (ja) | アルミニウム合金製ボルト | |
US10828693B2 (en) | Apparatus for manufacturing forged crankshaft | |
US20200101521A1 (en) | Method for producing forged crankshaft | |
JP2005014079A (ja) | 部分冷間強化コンロッドの製造方法 | |
KR101253810B1 (ko) | 구상화 열처리 단축을 위한 신선 가공용 다이스 | |
US20230304114A1 (en) | Aluminum sheet processing, aluminum component processing, and aluminum components | |
JP7018616B2 (ja) | アルミニウム合金製ボルト | |
CN114260403B (zh) | 盆状铝合金模锻件性能方向均匀性的锻造方法 | |
JP2010137248A (ja) | コンロッドの製造方法及びコンロッド | |
JP2006142355A (ja) | 座屈強度の優れた高強度軽量部品の製造方法及び製造された内燃機関用コンロッド。 | |
JP6387721B2 (ja) | 鍛造クランク軸の製造方法 | |
US20200086378A1 (en) | Method for producing forged crankshaft |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 16779731 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2017512189 Country of ref document: JP Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 15564034 Country of ref document: US |
|
WWE | Wipo information: entry into national phase |
Ref document number: 112016001755 Country of ref document: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 16779731 Country of ref document: EP Kind code of ref document: A1 |