JP2004167532A - Method for producing shaft pulley for belt type continuously variable transmission and die apparatus for forging the shaft pulley - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten a producing process without necessitating a post-processing by integrally forming a shaft and a pulley with a forging formation, in the shaft pulley for belt type continuously variable transmission. <P>SOLUTION: Dies 26 for forging is provided with a lower die 56 integrally disposed in the inner part of a body part 28, an upper die 52 displaced in the axial direction under driving action of a driving part 30, an upper pin member 54 for pressing the first shaft part 18 of a ternary forming product 24 as a work from an upper part, and a lower pin member 46 for pressing a second shaft part 20 of the ternary forming product 24 from a lower part. The outer peripheral surface of the first shaft part 18 is subjected to ironing-forming with fourth-fifth projecting parts 80, 82 formed in the through-hole 62b of the upper die 52 and also, the outer peripheral surface of the second shaft part 20 is subjected to ironing-forming with first-third projecting parts 70, 72, 74 formed in the through-hole 62a of a lower die 56, and thus, the dimensional precision of the outer peripheral diameters of the first and the second shaft parts 18, 20 are secured. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to, for example, a method of manufacturing a shaft pulley for a belt-type continuously variable transmission used in a continuously variable transmission constituting a power transmission device for an automobile, and a die device for forging the same.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a continuously variable transmission in which power from an automobile engine is transmitted by two pairs of pulleys and a belt connecting the pulleys without using a transmission gear has been employed.
[0003]
In the continuously variable transmission, a belt is wound around a groove defined between a driving pulley to which power from an engine is transmitted and a driven pulley to transmit the power to the driving side. By continuously changing the groove width defined in each of the side pulley and the driven side pulley, the belt changes in a radially inward direction or a radially outward direction of the drive side pulley and the driven side pulley, respectively. The gear ratio is steplessly changed. Then, power is transmitted to the driven pulley via the belt under the driving action of the driving pulley.
[0004]
The drive-side pulley and the driven-side pulley are each composed of a rod-shaped shaft portion and a substantially conical disk portion, which are formed separately, and are inserted into the shaft portion through a hole formed in a central portion of the disk portion. The shaft portion and the disk portion are integrally connected to each other by friction welding by frictional heat generated by rotating while pressing.
[0005]
Further, the belt is configured such that a plurality of metal plates are stacked along an axial direction, and the plurality of metal plates are integrally connected via a belt groove to form an annular shape (for example, Patent Document 1).
[0006]
[Patent Document 1]
JP-A-61-105368 (lower left column of page 2)
[0007]
Further, by sandwiching a rod-shaped shaft portion between rotating rollers in a rolling mill and rotating the rotating roller while urging a pressing force to press the outer peripheral surface of the shaft portion in the axial direction. A cross roll rolling manufacturing method for processing the shaft diameter of the shaft portion is known.
[0008]
[Problems to be solved by the invention]
By the way, in the method of manufacturing a shaft pulley for a belt-type continuously variable transmission according to the related art, under the influence of frictional heat generated when a shaft and a disk formed separately from each other are joined by friction welding. Thermal distortion occurs near the joint between the shaft and the disk. As a result, there is a concern that the axis distortion of the shaft portion may be reduced due to the thermal strain.
[0009]
Therefore, after integrally joining the shaft portion and the disk portion, post-processing is performed on the outer peripheral surface of the shaft portion in order to secure desired shaft center accuracy, but the number of processing steps increases, Accordingly, there is a problem that the manufacturing time increases.
[0010]
Further, in the case of processing the outer diameter of the shaft portion by the cross-roll rolling method, the meat flowing from the outer peripheral portion of the shaft portion under the pressing action of the rotating roll flows to both end portions of the shaft portion, The number of steps for performing post-processing such as removal of meat flowing toward both ends of the shaft increases. As a result, there is a problem that the cost increases due to an increase in the margin of the shaft portion.
[0011]
The present invention has been made in consideration of the above-described various inconveniences and the like. By integrally forming a shaft and a pulley by forging, it is possible to shorten a manufacturing process without the need for post-processing. An object of the present invention is to provide a method of manufacturing a shaft pulley for a belt-type continuously variable transmission and a die apparatus for forging the same.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a method of manufacturing a shaft pulley for a belt-type continuously variable transmission including a shaft portion and a conical flange portion of the shaft portion.
The upper die is pressed against the cylindrical forging material in the axial direction to form a shaft between the lower die and a conical flange portion whose diameter is increased in a radially outward direction at an intermediate portion of the shaft. Process and
In a state where the displacement of the forging material in the axial direction is restricted by the upper pin member, the upper die is displaced so as to be separated from the forging material, and the upper die provided on the inner peripheral surface of the upper die. A step of ironing the outer peripheral surface on one end side of the shaft portion by the protrusion,
The state in which the displacement of the forging material in the axial direction is restricted is released, and the forging material is pressed toward the upper die by a lower pin member, and the forging material is pressed down by the lower pin member. A step of ironing the outer peripheral surface on the other end side of the shaft portion by a lower mold projection provided on the inner peripheral surface of the mold,
It is characterized by having.
[0013]
According to the present invention, a shaft pulley having a shaft portion and a conical flange portion can be integrally formed by forging from a cylindrical forging material, and after the shaft pulley is formed, an upper die is formed. The outer peripheral surface on one end side of the shaft portion is iron-formed by the upper die protrusion of the upper die under the displacement action along the axial direction of the upper die, and the forging material is pressed in the direction of the upper die under the pressing action by the lower pin member. , And the outer peripheral surface on the other end side of the shaft portion is ironed by the lower die projection of the lower die.
[0014]
Therefore, by forming the shaft portion and the flange portion of the shaft pulley integrally by forging, the shaft portion of the shaft portion is compared with a case where the flange portion and the shaft portion are separately formed and joined. The shaft center accuracy can be improved.
[0015]
Also, by performing ironing on the outer peripheral surface of the shaft portion, the outer diameter of the shaft portion can be made to have a desired dimensional accuracy, so that the shaft portion is separately formed after the shaft pulley is forged. The post-processing process is simplified or unnecessary, and the manufacturing process of the shaft pulley can be shortened accordingly.
[0016]
Further, the step of integrally forming the shaft portion and the flange portion on the shaft pulley by forging and the step of ironing the outer peripheral surface of the shaft portion can be continuously performed. Can be shortened.
[0017]
Further, the present invention provides a forging die apparatus for forging a shaft pulley for a belt-type continuously variable transmission including a shaft portion and a conical flange portion of the shaft portion,
A drive unit;
An upper die that is displaced along the axial direction under the driving action of the driving unit,
An upper die projection formed on the inner peripheral surface of the upper die in a radially inward direction,
A lower mold integrally disposed inside the body,
A lower mold projection formed to protrude radially inward on the inner peripheral surface of the lower mold,
An upper pin member provided so as to be displaceable along the axial direction inside the drive unit,
A lower pin member provided so as to be displaceable along the axial direction inside the body,
It is characterized by having.
[0018]
According to the present invention, the upper mold projection is provided on the inner peripheral surface of the upper mold in a radially inward direction, and the lower mold projection is provided on the inner peripheral surface of the lower mold in the radially inward direction. Then, in a state where the displacement of the forging material is regulated by an upper pin member provided to be able to displace the inside of the driving portion along the axial direction, the outer peripheral surface on one end side of the shaft portion is ironed by the upper die projection. The forging material is displaced under the pressing action of a lower pin member which is formed and is displaceably provided in the body along the axial direction along the axial direction, and the outer peripheral surface on the other end side of the shaft portion by the lower mold projection. Ironing is performed.
[0019]
Therefore, by forming the shaft portion and the flange portion of the shaft pulley integrally by forging, the shaft portion of the shaft portion is compared with a case where the flange portion and the shaft portion are separately formed and joined. The shaft center accuracy can be improved.
[0020]
In addition, by performing ironing on the outer peripheral surfaces on one end side and the other end side of the shaft portion, the outer diameter of the shaft portion can be made to have a desired dimensional accuracy. The post-processing step for the shaft portion, which has been performed separately, is simplified or unnecessary, and accordingly, the manufacturing process of the shaft pulley can be shortened.
[0021]
Further, forging forming for forming a shaft portion and a flange portion on the shaft pulley and ironing forming performed on the outer peripheral surface of the shaft portion can be continuously performed by a forging die apparatus. The manufacturing process can be shortened.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method for manufacturing a shaft pulley for a belt-type continuously variable transmission and a die apparatus for forging the same according to the present invention will be described in detail below with reference to the accompanying drawings.
[0023]
In the method for manufacturing the shaft pulley 10 for a belt-type continuously variable transmission (hereinafter simply referred to as the shaft pulley 10) according to the present embodiment, forging work is performed four times on the work 12 formed of a cylindrical body made of a metal material. And finally the shaft pulley 10 (see FIG. 8) is manufactured.
[0024]
First, as shown in FIGS. 2A to 2E, the first and second shaft portions 18 and 20 formed on the shaft pulley 10 are heated as a pretreatment on the work 12 formed of a slightly larger cylindrical body. Is applied.
[0025]
Next, a first forging process is performed on the heated work 12 using a first forging die (not shown). Specifically, by pressing the work 12 from one end surface side, as shown in FIG. 2B, a first molded product 14 having a slightly larger outer diameter than the work 12 is obtained.
[0026]
Next, a second forging process is performed on the primary molded product 14. Specifically, the first molded article 14 is loaded into a work holding portion of a second forging die (not shown) having a cavity for forming a shaft portion and a cavity for forming a flange portion (not shown). The cavity for shaping the shaft is formed to have a small diameter with respect to the work 12.
[0027]
In this state, one end surface of the primary molded product 14 is pressed downward (in the direction of arrow X1) toward the cavity for molding the shaft portion. By this pressing, a flange portion 16 expanding radially outward at a substantially central portion of the primary molded product 14 and a first shaft portion (one end portion) having a plurality of steps at both end portions along the axial direction. ) 18 and a second molded product 22 on which the second shaft portion (the other end portion) 20 is formed (see FIG. 2C).
[0028]
Next, a third forging process is further performed on the second molded product 22. More specifically, a third forging die (not shown) is used to form the first and second shaft portions 18 and 20 so that the outer diameters of the first and second shaft portions 18 and 20 are further reduced. The tertiary molded product 24 which is expanded in the direction and becomes thinner is obtained (see FIG. 2D).
[0029]
Next, a process of further forging the tertiary molded product 24 and ironing the outer peripheral surfaces of the first and second shaft portions 18 and 20 will be described.
[0030]
First, the forging die device 26 that performs forging and ironing on the tertiary molded product 24 will be described.
[0031]
As shown in FIG. 1, the forging die device 26 includes a body portion 28, a driving portion 30 that is displaced in the axial direction under the driving action of a driving source (not shown), and a third molded product to be forged. There is provided a mold part 32 in which the inside 24 is loaded, and a pin mechanism 34 provided inside the body part 28 and the driving part 30 so as to be displaceable along the axial direction.
[0032]
The body portion 28 engages with a plate-shaped first base 38 mounted on the upper surface of the base 36, a second base 40 mounted on the upper portion of the first base 38, and an upper portion of the second base 40. And an annular outer ring 42. The base 36, the first and second bases 38 and 40, and the outer ring 42 are integrally connected via a bolt (not shown).
[0033]
At substantially the center of the first base 38 and the base 36, an insertion hole 44a is formed along the axial direction, and a lower pin member 46 is displaceable inside the insertion hole 44a from below the base 36. Has been inserted.
[0034]
The driving unit 30 includes a plate member 48 to which a pressing force is applied along an axial direction by supplying a current from a power source (not shown) to a driving source (not shown), and a bolt (not shown) on the lower surface of the plate member 48. And a connection member 50 integrally connected through the connection member. An upper mold 52, which is a part of the mold portion 32, is integrally engaged with the inside of the connection member 50 so as to protrude downward (in the direction of arrow X1).
[0035]
That is, the plate member 48, the connecting member 50, and the upper die 52 are integrally displaced in the axial direction under the driving action of the driving source (not shown).
[0036]
An insertion hole 44b is formed substantially in the center of the plate member 48 and the connection member 50 along the axial direction, and an upper pin member 54 is displaceably inserted into the insertion hole 44b from above. ing.
[0037]
The mold part 32 includes a lower mold 56 disposed inside the second base 40 and an upper mold 52 integrally provided inside the connection member 50.
[0038]
The upper surface of the lower die 56 is formed in a shape corresponding to the desired lower surface shape of the flange portion 16 of the shaft pulley 10.
[0039]
Further, on the outer peripheral surface of the lower mold 56, a convex portion 58a protruding in a radially outward direction is provided so as to be engaged with the concave portion 60a of the second base portion 40. Displacement of the mold 56 upward (in the direction of the arrow X2) is restricted.
[0040]
As shown in FIGS. 3 to 7, a through hole 62 a is formed substantially in the center of the lower mold 56 along the axial direction. Third lower holes 64, 66, and 68 are formed. The first to third pilot holes 64, 66, and 68 are formed such that the inner diameter of the first pilot hole 64 is the largest, and the second pilot hole 64 and the third pilot hole 68 decrease in this order. Is formed.
[0041]
In the first pilot hole 64, a first projection (lower die projection) 70 protruding from the inner peripheral surface by a predetermined length in a radially inward direction is formed on the second pilot hole 66 side, and In the lower hole 66, a second protrusion (lower die protrusion) 72 protruding by a predetermined length in a radially inward direction from the inner peripheral surface thereof is formed on the third lower hole 68 side. In the hole 68, a third protrusion (lower protrusion) 74 protruding from the inner peripheral surface by a predetermined length in a radially inward direction is formed on the side of the first base 38 (see FIG. 1).
[0042]
The inner peripheral surfaces of the first to third projections 70, 72, 74 are all formed so as to be substantially parallel to the axis. The inner diameters of the first to third protrusions 70, 72, 74 are also the same as the first to third pilot holes 64, 66, 68. The second protrusion 72 and the third protrusion 74 are formed so as to become smaller in this order.
[0043]
Furthermore, the inner diameters of the first to third protrusions 70, 72, 74 are formed so as to be substantially equal to the desired outer diameter of the second shaft portion 20 in the shaft pulley 10.
[0044]
The lower surface of the upper die 52 is formed in a shape corresponding to a desired upper surface shape of the flange portion 16 of the shaft pulley 10, and a convex portion 58 b projecting in a radially outward direction is connected to the outer peripheral surface of the upper die 52. It is engaged with the concave portion 60b of the member 50.
[0045]
A through hole 62b is formed substantially in the center of the upper die 52 along the axial direction, and the through hole 62b is formed with first and second upper holes 76 and 78 in order from below to above. Have been. The first and second upper holes 76 and 78 are formed such that the inner diameter of the first upper hole 76 is larger than the inner diameter of the second upper hole 78.
[0046]
In the first upper hole 76, a fourth protrusion (upper protrusion) 80 protruding from the inner peripheral surface by a predetermined length in a radially inward direction is formed on the lower mold 56 side, and the second upper hole 76 is formed. A fifth protrusion (upper protrusion) 82 protruding from the inner peripheral surface by a predetermined length in a radially inward direction from the inner peripheral surface is formed on the first upper hole 76 side.
[0047]
The inner peripheral surfaces of the fourth and fifth projections 80 and 82 are both formed so as to be substantially parallel to the axis. The inner diameters of the fourth and fifth protrusions 80 and 82 are also reduced in the order of the fourth protrusion 80 and the fifth protrusion 82, similarly to the first and second upper holes 76 and 78. Is formed. The inner diameter of the fourth and fifth protrusions 80 and 82 is larger than that of the fifth protrusion 82, similarly to the first and second upper holes 76 and 78. It is formed so that it becomes.
[0048]
Further, the loading portion 84 surrounded by the upper surface of the lower die 56 and the lower surface of the upper die 52 is loaded with the flange portion 16 of the tertiary molded product 24 and the second molded product 24 of the tertiary molded product 24. The shaft portion 20 is loaded so as to be inserted into the through hole 62 a of the lower mold 56.
[0049]
As shown in FIG. 1, the pin mechanism 34 includes a lower pin member 46 inserted into the insertion hole 44a of the body portion 28 and the through hole 62a of the lower die 56, an insertion hole 44b of the driving unit 30 and an upper die. 52, and an upper pin member 54 inserted into the through hole 62b.
[0050]
The lower pin member 46 is formed in a long shape, and the lower pin member 46 is displaced along the axial direction under the driving action of a driving source (not shown), and the upper surface thereof is always loaded in the through hole 62a. It is disposed so as to contact the lower surface of the second shaft portion 20 of the molded product 24.
[0051]
The upper pin member 54 is formed in a long shape, and when the upper pin member 54 is displaced downward (in the direction of arrow X1) along the axial direction under the driving action of a driving source (not shown), the lower surface of the upper pin member 54 becomes a through hole 62b. The tertiary molded product 24 is mounted on the first shaft portion 18 so as to contact the upper surface of the first shaft portion 18.
[0052]
Next, a process of further forging the tertiary molded product 24 by the forging die device 26 and performing ironing on the outer peripheral surfaces of the first and second shaft portions 18 and 20 will be described.
[0053]
First, as shown in FIG. 3, in a state where the upper die 52 is displaced upward (in the direction of arrow X2), the flange portion 16 of the tertiary molded product 24 to be a work is loaded into the loading portion 84, and The two shaft portions 20 are loaded into the through holes 62a of the lower mold 56.
[0054]
Then, under the driving action of a driving source (not shown), the upper die 52 descends along the axial direction so as to slide on the inner wall surface of the outer ring 42, and the lower surface of the upper die 52 is placed on the flange of the third molded product 24. It contacts the upper surface of the part 16. Then, the flange 16 is formed so as to have substantially the same shape as the lower surface of the upper mold 52 under the pressing action of the upper mold 52 (see FIG. 4).
[0055]
When the upper die 52 is displaced downward (in the direction of the arrow X1), the fourth and fifth protrusions 80 and 82 formed in the first and second upper holes 76 and 78 of the upper die 52 respectively. The outer peripheral surface of the first shaft portion 18 of the third molded product 24 is formed by ironing. At this time, since the inner diameters of the fourth and fifth protrusions 80 and 82 are different, the outer diameter of the upper part of the first shaft part 18 is smaller than the outer diameter of the lower part corresponding to the inner diameter. It is formed into a shape.
[0056]
Then, in a state where the lower surface of the upper mold 52 is in contact with the upper surface of the flange portion 16 of the tertiary molded product 24, as shown in FIG. 5, the upper pin member 54 is driven by a driving source (not shown). The inside of the insertion hole 44b of the section 30 and the inside of the through hole 62b of the upper mold 52 are displaced downward (in the direction of arrow X1) along the axial direction, and the upper pin member 54 moves down the upper surface of the first shaft section 18 (arrow X1). Direction).
[0057]
As a result, the outer peripheral portion of the first shaft portion 18 plastically flows in a direction substantially perpendicular to the axis (the direction of arrow A) under the pressing action of the upper pin member 54, and the outer peripheral portion is plastically deformed and out of the radius. By expanding the diameter in the direction, the inner peripheral surfaces of the first and second upper holes 76 and 78 of the upper die 52 come into contact with each other.
[0058]
At substantially the same time, the lower pin member 46 is displaced upward (in the direction of arrow X2) along the axial direction inside the insertion hole 44a of the body portion 28 and the through hole 62a of the lower mold 56 under the driving action of a driving source (not shown). Then, the lower pin member 46 presses the lower surface of the second shaft portion 20 of the tertiary molded product 24 upward (in the direction of the arrow X2).
[0059]
As a result, the outer peripheral portion of the second shaft portion 20 plastically flows in a direction substantially perpendicular to the axis (the direction of arrow A) under the pressing action of the lower pin member 46, and the outer peripheral portion of the second shaft portion 20 becomes plastic. By deforming and expanding in the radially outward direction, the lower die 56 comes into contact with the inner peripheral surfaces of the first to third lower holes 64, 66, 68.
[0060]
In other words, since the first and second shaft portions 18 and 20 are in a state where the axial displacement (the directions of the arrows X1 and X2) is regulated by the upper pin member 54 and the lower pin member 46, the upper pin member 54 and the When pressed by the lower pin member 46, the flesh of the outer peripheral portions of the first and second shaft portions 18, 20 flows only in the radially outward direction (the direction of arrow A).
[0061]
Next, as shown in FIG. 6, in a state where the upper surface of the first shaft portion 18 is held by the upper pin member 54, the upper die 52 is moved upward (in the direction of the arrow X2) under the driving action of a driving source (not shown). And displacement. At this time, the outer peripheral portion of the first shaft portion 18 is in a state of being plastically deformed radially outward so as to abut against the inner peripheral surface of the upper die 52 under the pressing action of the upper pin member 54 and expanded. The fourth and fifth protrusions 80 and 82 on the inner peripheral surface of the upper die 52 are displaced upward (in the direction of arrow X2), and the outer peripheral portion of the first shaft portion 18 whose diameter has been increased by plastic deformation is upward (see arrow). (X2 direction).
[0062]
In other words, the flesh of the outer peripheral portion of the first shaft portion 18 plastically flows upward (in the direction of the arrow X2) under the displacement action of the fourth and fifth protrusions 80 and 82, and the outer peripheral diameter of the first shaft portion 18 is reduced. The fourth and fifth projections 80 and 82 are formed by ironing so as to have substantially the same inner diameter.
[0063]
As a result, the outer diameter of the first shaft portion 18 is formed with the desired dimensional accuracy by the fourth and fifth protrusion portions 80 and 82, respectively. Since the upper surface of the first shaft portion 18 is regulated by the upper pin member 54, the tertiary molded product 24 is displaced above the upper die 52 (in the direction of the arrow X2). The product 24 is not displaced upward (in the direction of the arrow X2).
[0064]
Next, as shown in FIG. 7, in a state where the upper mold 52 is displaced upward (in the direction of the arrow X2) with respect to the tertiary molded product 24 loaded in the loading section 84, a drive source (not shown) The lower pin member 46 is displaced upward (in the direction of the arrow X2) integrally with the upper pin member 54 under the driving action of. Then, the lower surface of the second shaft portion 20 is pressed by the lower pin member 46, and the third molded product 24 is displaced so as to be pushed up (in the direction of the arrow X2).
[0065]
At this time, the outer peripheral portion of the second shaft portion 20 is plastically deformed radially outward so as to abut against the inner peripheral surface of the through hole 62a of the lower die 56 under the pressing action of the lower pin member 46, and the outer diameter is increased. In this state, the second shaft portion 20 is displaced upward (in the direction of the arrow X2) with respect to the first to third protrusions 70, 72, 74 on the inner peripheral surface of the lower mold 56, and expands due to plastic deformation. The outer peripheral portion of the diameter of the second shaft portion 20 is drawn down (along arrow X1) along the axial direction. At this time, since the first to third protrusions 70, 72, and 74 have different inner peripheral diameters, the outer peripheral diameter above the second shaft portion 20 is larger than the outer peripheral diameter below the second shaft part 20 corresponding to the inner peripheral diameter. It is formed in a stepped shape.
[0066]
In other words, the flesh of the outer peripheral portion of the second shaft portion 20 plastically flows downward (in the direction of the arrow X1) under the displacement action of the second shaft portion 20 with respect to the first to third protrusions 70, 72, 74, Ironing is performed so that the outer diameter of the second shaft portion 20 is substantially equal to the inner diameter of the first to third protrusions 70, 72, 74. As a result, the outer diameter of the second shaft portion 20 is formed with desired dimensional accuracy by the first to third protrusions 70, 72, 74.
[0067]
Then, as shown in FIG. 8, the first and second shaft portions 18 and 20 having desired dimensional accuracy are secured by ironing with the first to fifth protrusions 70, 72, 74, 80 and 82. The shaft pulley 10 is obtained.
[0068]
As described above, in the present embodiment, the first and second shaft portions 18 and 20 and the flange portion 16 functioning as a pulley are integrally forged with the shaft pulley 10 to form the first and second shaft portions. Compared with the case where the shaft portions 18 and 20 and the flange portion 16 are separately provided and joined, the axis accuracy of the first and second shaft portions 18 and 20 with respect to the flange portion 16 can be improved.
[0069]
Further, after the first and second shaft portions 18 and 20 and the flange portion 16 are integrally forged, the outer peripheral surface of the first shaft portion 18 is formed by the fourth and fifth projections 80 and 82 of the upper die 52. By ironing and by ironing the outer peripheral surface of the second shaft portion 20 with the first to third projections 70, 72, 74 of the lower die 56, the shaft pulley 10 formed by forging is separated. Since the post-processing of processing the outer peripheral surfaces of the first and second shaft portions 18 and 20 becomes unnecessary, the manufacturing process and the manufacturing time can be shortened accordingly.
[0070]
Further, a step of integrally forming the first and second shaft portions 18 and 20 and the flange portion 16 by forging, and a first to a first steps for the outer peripheral surfaces of the first and second shaft portions 18 and 20. Since the ironing process through the five protrusions 70, 72, 74, 80, and 82 is continuously performed by the forging die device 26, the manufacturing process and the manufacturing time of the shaft pulley 10 can be reduced. it can.
[0071]
【The invention's effect】
According to the present invention, the following effects can be obtained.
[0072]
That is, since the shaft portion and the flange portion of the shaft pulley can be integrally formed by forging, the accuracy of the shaft center of the shaft portion can be improved.
[0073]
Also, by performing ironing on the outer peripheral surface of the shaft portion, the outer diameter of the shaft portion can be made to have a desired dimensional accuracy. Therefore, the shaft which has been separately formed after the shaft pulley is forged. Since the post-processing step to the part becomes unnecessary, the step of forming the shaft part and the flange part on the shaft pulley and the step of ironing the outer peripheral surface of the shaft part can be continuously performed, The manufacturing process of the shaft pulley can be shortened.
[Brief description of the drawings]
FIG. 1 is a partially omitted vertical sectional view of a forging die apparatus used in a method of manufacturing a shaft pulley for a belt-type continuously variable transmission according to an embodiment of the present invention.
FIG. 2 is an explanatory view showing a forging process for a work.
FIG. 3 is an enlarged vertical sectional view showing a state in which an upper die of a forging die device in FIG. 1 is positioned upward.
4 is an operation explanatory view showing a state in which an upper die of the forging die device in FIG. 3 is displaced downward, and a lower surface of the upper die is in contact with an upper surface of a flange portion of a tertiary molded product.
FIG. 5 shows that the upper pin member of the forging die apparatus in FIG. 4 is displaced downward, and the lower pin member is displaced upward, so that the first and second pins are pressed by the upper pin member and the lower pin member. It is operation | movement explanatory drawing which shows the state which the outer peripheral diameter of the 2 shaft part expanded.
FIG. 6 shows a state in which the upper die of the forging die apparatus in FIG. 5 is displaced upward, and the outer peripheral surface of the first shaft portion of the tertiary molded product is ironed by the fourth and fifth protrusions. FIG.
FIG. 7 shows a lower pin member and an upper pin member of the forging die device shown in FIG. 6 displaced upward, pushing out the tertiary molded product upward, and the second shaft portion by the first to third protrusions. FIG. 5 is an operation explanatory view showing a state in which the outer peripheral surface of the iron is formed by ironing.
8 is a perspective view of a shaft pulley in which ironing has been performed on the outer peripheral surfaces of the first and second shaft portions by the forging die apparatus in FIG. 1. FIG.
[Explanation of symbols]
10: Shaft pulley 14: Primary molded product
16 Flange part 18 First shaft part
20: Second shaft part 22: Secondary molded product
24: Third molded product 26: Forging die device
28: body part 30: drive part
32 mold part 34 pin mechanism
38: first base 40: second base
44a, 44b: insertion hole 46: lower pin member
52: Upper die 54: Upper pin member
56: Lower mold 62a, 62b: Through hole
64: first pilot hole 66: second pilot hole
68: third pilot hole 70: first protrusion
72: second projection 74: third projection
76: first upper hole 78: second upper hole
80: fourth protrusion 82: fifth protrusion
84 Loading section

Claims (2)

A method for manufacturing a shaft pulley for a belt-type continuously variable transmission, comprising a shaft portion and a conical flange portion of the shaft portion,
The upper die is pressed against the cylindrical forging material in the axial direction to form a shaft between the lower die and a conical flange portion whose diameter is increased in a radially outward direction at an intermediate portion of the shaft. Process and
In a state where the displacement of the forging material in the axial direction is restricted by the upper pin member, the upper die is displaced so as to be separated from the forging material, and the upper die provided on the inner peripheral surface of the upper die. A step of ironing the outer peripheral surface on one end side of the shaft portion by the protrusion,
The state in which the displacement of the forging material in the axial direction is restricted is released, and the forging material is pressed toward the upper die by a lower pin member, and the forging material is pressed down by the lower pin member. A step of ironing the outer peripheral surface on the other end side of the shaft portion by a lower mold projection provided on the inner peripheral surface of the mold,
A method of manufacturing a shaft pulley for a belt-type continuously variable transmission, comprising: In a forging die apparatus for forging a shaft pulley for a belt-type continuously variable transmission comprising a shaft portion and a conical flange portion of the shaft portion,
A drive unit;
An upper die that is displaced along the axial direction under the driving action of the driving unit,
An upper die projection formed on the inner peripheral surface of the upper die in a radially inward direction,
A lower mold integrally disposed inside the body,
A lower mold projection formed to protrude radially inward on the inner peripheral surface of the lower mold,
An upper pin member provided so as to be displaceable along the axial direction inside the drive unit,
A lower pin member provided so as to be displaceable along the axial direction inside the body,
A die device for forging, comprising:

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