JP2012061522A - Method of forming thickened part of shaft, and apparatus for manufacturing thickened part of shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of forming a thickened part of a shaft and an apparatus for manufacturing the thickened part of the shaft, which can form the thickened part in a large size, surely improve fitting connection strength, and enable a thickening process with good production efficiency.SOLUTION: A pair of holders 41, 42 for holding a metal shaft 10 is arranged while the shaft 10 is inserted into an insertion hole of a member to be fitted 20. The holders 41, 42 move so as to bend the metal shaft 10 at a bending point while rotating the shaft 10 around a reference axis CL. In the method of forming the thickened part and the apparatus for manufacturing the thickened part, a diameter of the shaft 10 is increased to fix the member to be fitted 20 with the shaft 10. The apparatus includes pressing portions 51, 52 that can press both end surfaces of the shaft 10. Consequently, tensile stress generated in the shaft 10 is effectively suppressed.

Description

  The present invention relates to a technique for thickening a shaft made of metal, and more particularly, to a method for forming an enlarged portion of a shaft and a manufacturing apparatus suitable for application to an enlargement fitting method.

Conventionally, as a method of connecting a metal shaft and a fitted member having an insertion hole through which the shaft is inserted, there is a method of enlarging the shaft and fixing it to the insertion hole (Patent Document 1).
In this method, after the shaft is fitted into the insertion hole of the fitted member, the shaft is bent near the insertion hole of the shaft when the shaft is rotated together with the fitted member in the axial direction while rotating on the axis. Add As a result, the fitting portion is plastically deformed to increase the diameter, and is fitted into the insertion hole, so that the shaft and the fitted member are firmly fixed.

JP 2009-178732 A

  The above-mentioned enlargement fitting method can be tightly coupled as compared with shrink fitting, caulking, and the like, but there are various purposes of using the products produced by this enlargement fitting. In a rotating body that transmits a driving force such as the above, there is a demand for stronger fixation than ever, and an improvement in the coupling force of the fitting portion is desired.

  Moreover, in the conventional enlarged part forming method, as disclosed in Patent Document 1, a method of enlarging the part of the bending point of the shaft by bending the shaft at one bending point while rotating the shaft. Therefore, there is a possibility that a crack may occur on the outside of the bent portion, that is, on the portion corresponding to the pull side of the shaft. For this reason, the bending angle is limited to a range where cracks do not occur, and there is a limit to the range where enlargement can be achieved. In particular, depending on the material and strength of the shaft, there is a case where it is difficult to achieve the desired bend, and there is a case where the coupling force between the members to be fitted is not sufficient.

  The present invention has been made in view of the circumstances described above, and its purpose is to increase the enlarged portion by suppressing the occurrence of cracks even when the enlarged portion of the shaft made of metal is difficult to enlarge. An object of the present invention is to provide a method and a manufacturing apparatus for forming an enlarged portion of a shaft that can be formed and can reliably improve the coupling force.

  In order to achieve the above-mentioned object, the invention according to claim 1 is characterized in that a metal shaft is inserted into an insertion hole of a member to be fitted, and the shaft is fitted into the insertion hole in a state where the shaft is fitted into the insertion hole. And is rotated on the held reference axis line, and the fitted portion is bent at a predetermined bending point with respect to the reference axis line, thereby increasing the diameter of the shaft. In the enlarged portion forming method for fixing the fitting member and the shaft, the diameter of the shaft is increased while pressurizing both end faces of the shaft.

  In addition to the structure of Claim 1, the invention which concerns on Claim 2 performs pressurization to the both end surfaces of the said shaft via the pressurization part which operate | moves independently of operation | movement of the said holder. Features.

  The invention according to claim 3 is characterized in that, in addition to the configuration according to claim 2, the pressing of the shaft by the pressurizing unit is performed through a holder opening that opens both end faces of the shaft.

  The invention according to claim 4 is characterized in that, in addition to the configuration according to claim 2 or 3, the center axis of the pressurizing portion is always aligned with the center of rotation of the holder.

  In addition to the structure of any one of Claims 2-4, the invention which concerns on Claim 5 makes the said pressurization part rotate following the rotation of the said holder, It is characterized by the above-mentioned.

  The invention according to claim 6 is characterized in that, in addition to the configuration according to any one of claims 2 to 5, pressurization from both end surfaces to the shaft by the pressurizing unit is performed equally. To do.

  According to a seventh aspect of the present invention, in addition to the configuration according to any one of the second to sixth aspects, the contact between the two end surfaces of the shaft and the separation by the pressurizing unit is the same for both the holders. It is performed when it is located on a line.

  The invention according to claim 8 is provided with a pair of holders for gripping the shaft in a state in which the metal shaft is inserted through the insertion hole of the fitted member, and the holder rotates the shaft around its reference axis. In the manufacturing apparatus for fixing the fitted member and the shaft by increasing the diameter of the shaft by moving the portion corresponding to the insertion hole to bend at a bending point while It is characterized by comprising a pressurizing part capable of pressurizing both end faces of the shaft.

  According to a ninth aspect of the present invention, in addition to the configuration according to the eighth aspect, the pressurizing unit that pressurizes both end surfaces of the shaft is configured to operate independently of the operation of the holder. It is characterized by that.

  According to a tenth aspect of the present invention, in addition to the configuration according to the eighth or ninth aspect, a holder opening that enables the pressing of the shaft by the pressing portion is configured to open both end faces of the shaft. It is characterized by.

  According to an eleventh aspect of the present invention, in addition to the configuration according to any one of the eighth to tenth aspects, the pressurizing portion has both central holders on both sides of the bending point, and the center axes of the two holders. It is constituted so that it may correspond to each rotation axis of each.

  The invention according to a twelfth aspect is characterized in that, in addition to the configuration according to any one of the eighth to eleventh aspects, the pressurizing portion is configured to rotate following the rotation of the holder. And

  According to a thirteenth aspect of the present invention, in addition to the configuration according to any one of the eighth to twelfth aspects, the pressurizing unit is configured so that the pressurization from both end surfaces to the shaft is uniform. It is characterized by that.

  In the invention according to claim 14, in addition to the configuration according to any one of claims 8 to 13, the pressurizing portion is configured so that the contact operation and the separation operation with respect to both end surfaces of the shaft are both performed by the holder. Are configured to be performed when they are located on the same axis.

  According to the first aspect of the invention, when the shaft diameter is increased by bending the fitted portion with respect to the reference axis, the diameter of the shaft is increased while pressing both end faces of the shaft. Generation | occurrence | production of the tensile stress to generate | occur | produce can be suppressed effectively. Therefore, the occurrence of cracks in the vicinity of the enlarged portion can be suppressed and the enlarged portion can be formed larger, and the range of the bending angle of the shaft can be expanded to expand the application range of the enlarged fitting method.

  According to the second aspect of the present invention, since pressure is applied to both end faces of the shaft via the pressure unit that operates independently of the operation of the holder, the pressure is not restricted by the movement of the holder. Since it can be set independently as desired, it is possible to selectively apply a pressure level and pressurization timing optimum for forming the enlarged portion selectively on the axis.

  According to the invention of claim 3, since the pressing of the shaft by the pressing portion is performed through the holder opening that opens both end surfaces of the shaft, the pressing can be independent of the operation of the holder, and the shaft grip of the holder is affected. The shaft can be surely pressed without giving.

  According to the invention of claim 4, by always making the central axis of the pressurizing portion coincide with the rotation center of the holder, the pressurization is always applied to the shaft even when the holder is inclined when the enlarged portion is formed. It is possible and can fully exert the pressurizing action.

  According to the fifth aspect of the present invention, the wear of the end face of the shaft and the pressurizing part can be suppressed by rotating the pressurizing part following the rotation of the holder, and without worrying about the wear. It is possible to apply a large pressure. In addition, a decrease in accuracy between members due to wear of the end face of the shaft and the pressurizing portion is prevented, and adverse effects on molding accuracy due to wear are avoided.

  According to the invention of claim 6, by applying pressure from both end surfaces to the shaft by the pressurizing portion evenly, an unexpected bias of the compressive stress of the shaft is avoided, and deformation of the shaft other than the enlarged portion is avoided. Can be effectively suppressed.

  According to the seventh aspect of the present invention, since both the holders are in contact with and separated from the both end faces of the shaft by the pressurizing portion, the unexpected stress on the shaft is avoided. In addition, the enlarged portion can be formed under favorable conditions. In other words, when the end of the shaft and the pressurizing unit are in contact with or separated from each other when the holder is tilted, an unstable load may easily be applied to the shaft, which may be twisted, but this can be avoided.

  According to the invention of claim 8, by providing a pressurizing portion that can pressurize both end faces of the shaft when moving so as to bend at the bending point while rotating the shaft around its reference axis. It is possible to effectively suppress the generation of tensile stress generated in the shaft and to suppress the generation of cracks around the enlarged portion. Therefore, it is possible to provide a manufacturing apparatus that can expand the range of the bending angle of the shaft and expand the application range of the enlargement fitting method.

  According to invention of Claim 9, since the pressurization part which pressurizes to the both end surfaces of an axis | shaft is comprised so that it may operate | move independently of operation | movement of a holder, pressurization is a movement of a holder. It can be controlled completely, and the optimum pressure for forming the enlarged portion can be applied freely.

  According to the invention of claim 10, since the holder opening that enables the pressing of the shaft by the pressing portion is configured to open both end faces of the shaft, the pressing can be independent of the operation of the holder, The shaft can be reliably pressurized without affecting the holder's shaft grip.

  According to the eleventh aspect of the present invention, the pressurizing portion is configured such that the central axes thereof coincide with the respective rotational axes of the holders on both sides of the bending point, so that the enlarged portion is formed. Even when the holder is tilted at the time of formation, accurate and appropriate pressure can always be applied to the shaft, and the pressurizing action on the shaft can be sufficiently exerted.

  According to the invention of claim 12, since the pressurizing part is configured to rotate following the rotation of the holder, it is possible to suppress wear between the end face of the shaft and the pressurizing part. It is possible to apply a large pressing force without worrying about it, and it is possible to prevent a decrease in accuracy between members due to wear and to avoid adverse effects on molding accuracy due to wear.

  According to invention of Claim 13, since the pressurization part is comprised so that the pressurization from the both end surfaces to a shaft may become equal, it suppresses deformation | transformation other than the enlarged part of a shaft effectively. Can do. Moreover, the load on the shaft holding structure of the manufacturing apparatus can be reduced by maintaining the pressure balance in the axial direction.

  According to the invention of claim 14, the pressurizing portion is configured such that the contact operation and the separation operation with respect to both end faces of the shaft are performed when both of the holders are located on the same axis line. It is possible to avoid the occurrence of unexpected stress on the shaft and to always form the enlarged portion under favorable conditions. If the end of the shaft with the tilted holder is in contact with or separated from the pressurizing unit, an unstable load may be easily applied to the shaft, which may cause twisting. Good manufacturing equipment can be provided.

It is sectional drawing which shows the state before the assembly of the rotary body used for one Embodiment which concerns on this invention. It is sectional drawing which shows the insertion state of the to-be-fitted member and axis | shaft which are shown in FIG. It is a schematic sectional drawing of the holding part of the rotary body in the manufacturing apparatus for enforcing the enlarged part formation method which concerns on this invention. It is a principal part schematic sectional drawing for demonstrating a manufacturing process in the manufacturing apparatus for enforcing the enlarged part formation method which concerns on this invention. It is a principal part schematic sectional drawing for demonstrating a manufacturing process in the manufacturing apparatus for enforcing the enlarged part formation method which concerns on this invention. It is a principal part schematic sectional drawing for demonstrating a manufacturing process in the manufacturing apparatus for enforcing the enlarged part formation method which concerns on this invention. It is a principal part schematic sectional drawing for demonstrating a manufacturing process in the manufacturing apparatus for enforcing the enlarged part formation method which concerns on this invention. It is a principal part schematic sectional drawing for demonstrating a manufacturing process in the manufacturing apparatus for enforcing the enlarged part formation method which concerns on this invention. It is a principal part schematic sectional drawing for demonstrating a manufacturing process in the manufacturing apparatus for enforcing the enlarged part formation method which concerns on this invention. It is principal part sectional drawing of the assembly state of the rotary body in 1st Embodiment of this invention. It is principal part sectional drawing of the assembly state of the rotary body in 2nd Embodiment of this invention. It is principal part sectional drawing of the assembly state of the rotary body in 3rd Embodiment of this invention. It is principal part sectional drawing of the assembly state of the rotary body in 4th Embodiment of this invention. It is explanatory drawing for demonstrating the continuous movement of the bending point in the enlarged part formation method of 1st Embodiment which concerns on this invention. It is explanatory drawing for demonstrating the intermittent movement of the bending point in the enlarged part formation method of 5th Embodiment which concerns on this invention. It is a side view of the manufacturing apparatus of the rotating body in a 1st embodiment concerning the present invention. It is a top view of the manufacturing apparatus shown in FIG. It is sectional drawing in the III-III line of the manufacturing apparatus shown in FIG. It is a graph which shows the relationship between the back pressure load in the manufacturing method which concerns on this invention, the deformation | transformation amount of a shaft, and a crack.

(First embodiment)
Hereinafter, the enlarged part formation method concerning this invention and the manufacturing apparatus which enforces this enlarged part formation method are demonstrated.
In addition, before demonstrating the enlarged part formation method of this invention, 1st Embodiment of the rotary body manufactured by the enlarged part formation method and its manufacturing apparatus is described. This embodiment will be described with reference to FIGS. 1 and 2 showing a rotating body, FIGS. 14 and 16 to 18 showing a manufacturing apparatus and a manufacturing process. Further, the viewing direction of each drawing is viewed from the direction in which the reference numerals are described.

  As shown in FIG. 1, the rotating body 1 of the present embodiment is composed of two members, a hollow shaft 10 and a fitted member 20 to which the shaft 10 is fitted, as shown in FIG. 1. Yes. The rotating body 1 is applied as a power transmission member of an automobile, for example. The shaft 10 is a CVT pulley shaft, and the fitted member 20 is a sheave.

As shown in FIG. 1, the fitted member 20 is a disk-shaped member having an insertion hole 21 at the center. The inner peripheral surface 21a of the insertion hole 21 is provided with a groove 22 configured in an annular shape over the entire circumference. When manufacturing the member 20 to be fitted, the groove 22 is a lightening portion that avoids the thickness of the portion closer to the center to make the thickness of the entire sheave uniform and reduce the weight.
Accordingly, the groove 22 is formed considerably deeper from the inner peripheral surface 21a, and is very easily formed in the manufacturing process when the fitted member 20 is manufactured by casting.

FIG. 2 shows the rotating body 1 (a workpiece before being assembled into the manufacturing apparatus 40) before being processed in a state where the shaft 10 is inserted into the insertion hole 21.
In addition, when inserting the axis | shaft 10 in the to-be-fitted member 20, you have to position to the predetermined insertion position 12 (refer FIG. 1). In the present embodiment, the insertion position is positioned accurately by the inner peripheral end 23 of the fitted member 20 coming into contact with, for example, a stopper portion 11 provided as a protrusion on the outer periphery of the shaft 10. It can be done.

The manufacturing apparatus 40 of this embodiment is demonstrated.
As shown in FIGS. 16 to 18, the manufacturing apparatus 40 has a reference axis CL on which the axis 10 of the workpiece (the rotating body 1 before completion shown in FIG. 2) is arranged. It extends horizontally in the longitudinal direction of the device. The manufacturing apparatus 40 includes a fixed side holder unit 42 a and a movable side holder unit 41 a for gripping the shaft 10.
As shown in FIG. 16, the fixed holder unit 42a and the movable holder unit 41a are disposed on the reference axis CL so as to be spaced apart from each other. Both holder units 41a and 42a are provided with holders 41 and 42 (see FIG. 3) that can hold both ends of the workpiece shaft 10 and hold the fitted member 20 appropriately.

Further, as shown in FIG. 16, the manufacturing apparatus 40 includes a base plate 60 at the lowest position below the reference axis CL. The base plate 60 is configured to extend along the reference axis CL. With this base plate 60 as a base, an apparatus frame 61 is disposed thereon.
As shown in FIG. 16, a pair of support walls 70 (see also FIG. 17) are provided on the left side of the device frame 61, and a fixed-side support portion 85 a that protrudes further to the left side than the support wall 70 is provided. It has been.

  As shown in FIG. 17, the support wall 70 is disposed with the reference axis CL interposed therebetween, and is erected on the base plate 60. The fixed-side holder unit 42a is supported between the support walls 70. The support portion 85a is provided on the base plate 60, and is configured to be able to support a fixed-side pressurizing mechanism 85 that pressurizes the end portion of the shaft 10 on the reference axis CL.

The fixed-side holder unit 42a includes a fixed-side holder 42 that grips a workpiece, a fixed-side housing 42b that supports the fixed-side holder 42, and a rotation drive mechanism 71 that rotationally drives the fixed-side holder 42. Yes. The fixed side holder 42 is fixed in a direction along the reference axis CL, and is supported so as to be rotatable around the reference axis CL.
Therefore, the fixed side holder 42 is rotated in a fixed direction by receiving the rotational driving force from the rotational driving mechanism 71.

Further, as shown in FIG. 3 (FIG. 3 shows a state in which the workpiece is gripped), the fixed-side holder 42 grips the workpiece shaft 10 so that the end surface 10a of the shaft 10 can be seen from the rear end side of the holder. A holder opening 42k to be opened is provided. The pressurizing portion 52 is disposed so as to enter the holder opening 42k and come into contact with the end portion of the shaft 10. The pressurizing unit 52 is connected to the pressurizing shaft 88 of the fixed-side pressurizing mechanism 85 described above, and is configured to pressurize the end of the shaft 10 in the axial direction.
That is, in cooperation with the movable-side pressurizing portion 51 described later, the diameter of the shaft 10 is increased while applying a back pressure load to the both end faces 10a and 10b with the shaft 10 directed toward the center of the shaft. Is possible.

In the present embodiment, the pressurization by the pressurizing unit 52 to the end of the shaft 10 is configured to be able to operate independently of the operation of the holder 42. That is, the pressurizing shaft 88 of the fixed-side pressurizing mechanism 85 may or may not rotate in conjunction with the rotational operation of the holder 42, but the axial movement operates independently, and the pressurizing unit 52 is moved along the reference axis CL. Therefore, the back pressure load optimum for forming the enlarged portion can be selectively and freely applied to the shaft 10 (selectively the timing and magnitude of pressure application). , 10b, the back pressure load can be easily applied evenly.
Further, the central axis of the pressurizing unit 52 coincides with the reference axis CL together with the pressurizing shaft 88 and is configured to always coincide with the rotation center of the holder 42.

  The pressurizing unit 52 is configured to be able to rotate following the holder 42. Thereby, abrasion of the contact part of the axis | shaft 10 and the pressurization part 52 is suppressed, and a big pressurizing force can be applied. Also, adverse effects on the molding accuracy due to wear can be avoided.

The movable side holder unit 41a disposed opposite to the above-mentioned fixed side holder unit 42a will be described.
The movable-side holder unit 41a includes a movable-side holder 41 that holds the end of the workpiece and a movable-side housing 41b that supports the holder 41.
The movable-side holder 41 has a cylindrical shape as shown in FIG. 18, and a movable-side housing 41b surrounds the holder 41 and is supported so as to be rotatable about a predetermined axis CL1.

Moreover, the movable side holder unit 41a is arrange | positioned on the top stage 66 so that FIG. 18 may show.
The top stage 66 is supported by a swing rail 65 described later, the swing rail 65 is supported by a swing base 64, and the swing base 64 is installed on a slide base 63. The slide table 63 is slidably supported in the longitudinal direction of the apparatus by a pair of guide beds 62 as guide means.
The guide bed 62 is attached to the upper end of the apparatus frame 61, and as is apparent from FIG. 17, is disposed on both the left and right sides of the apparatus main body with the reference axis line CL interposed therebetween, and is arranged in a horizontal plane along the reference axis line CL. It extends parallel to.
By being configured in this way, the movable side holder unit 41a can freely approach and separate from the fixed side holder unit 42a along the reference axis CL.

As can be seen from FIGS. 16 and 17, the slide base 63 is slid along the reference axis CL by a slide base drive mechanism 69 attached to the right end of the apparatus frame 61.
In the present embodiment, the pressure applied to the shaft 10 has a pressurizing mechanism described later that is driven independently of the holder 41, but the holder on the fixed side with respect to the holder 41 by the slide base driving mechanism 69. It is also possible to apply a pressing force toward the 42 side.

Further, as shown in FIG. 18, a rocking table 64 is supported on the slide table 63 so as to be able to rock in the horizontal direction about a rocking shaft 68. The swing table 64 is provided with a swing table drive cylinder 80 as a swing drive mechanism at a position opposite to the swing shaft 68 with the movable holder unit 41a interposed therebetween. The swing rod drive cylinder 80 has a piston rod 81 pivotally supported via a mounting portion 82.
A top stage 66 is disposed on the swing table 64 as described above, and the movable side holder unit 41 a is fixed between a pair of support walls 67 erected on the top stage 66.

  The top stage 66 is held so as to be swingable in the horizontal direction on the swing base 64. That is, it is slidably supported on a pair of arcuate swing rails 65 provided on the swing base 64 and centered on the virtual fulcrum Z. As a drive mechanism for swinging the top stage 66, as shown in FIGS. 17 and 18, for example, the top stage drive cylinder 75 is connected to a support wall 67 on one side of the top stage 66 via a connector 76. It is a connected configuration. Therefore, the top stage 66 can swing along the swing rail 65 by the expansion and contraction of the top stage drive cylinder 75.

  By being configured in this way, the movable side holder unit 41a can perform two kinds of tilt movements that intersect the axis CL with respect to the reference axis CL. This is a swing operation of the swing base 64 by the swing base drive cylinder 80 and a swing operation of the top stage 66 by the top stage drive cylinder 75. That is, the oscillating base 64 can be oscillated by the oscillating base driving cylinder 80 to perform the first inclined movement (formation of the bending start point) of the axis CL, and the top stage driving cylinder 75 can further perform the top stage. 66 can swing and perform a second tilt movement (movement of the bending point).

Here, also in the movable side holder unit 41a, as shown in FIG. 3, the movable side holder 41 holds the workpiece shaft 10, and opens so that the end surface 10b of the shaft 10 can be seen from the rear end side of the holder. A holder opening 41k is provided. Therefore, the pressurizing portion 51 is configured to be able to enter the holder opening 41k and come into contact with the end surface 10b of the shaft 10.
The pressurizing unit 51 is connected to a pressurizing shaft 89 of the movable-side pressurizing mechanism 86, and is configured to be applied with a back pressure load that pressurizes the end surface 10b of the shaft 10 in the axial direction. That is, it is possible to pressurize both end surfaces 10a and 10b of the shaft 10 in cooperation with the above-described fixed-side pressurizing portion 52.
The movable pressure mechanism 86 is appropriately supported by a movable support 86a on the top stage 66.

Further, the structures of the movable-side pressurizing mechanism 86 and the fixed-side pressurizing mechanism 85 are not particularly limited, but a configuration using hydraulic means can be adopted. Thereby, the enlargement of the manufacturing apparatus 40 can be avoided.
Furthermore, both the pressurizing parts 51 and 52 are rotatably held around the axis, and are configured to be rotatable within the holder. It should be noted that both the pressurizing portions 51 and 52 are preferably configured as separate members from the pressurizing shaft 88 of the movable side pressurizing mechanism 86 and the pressurizing shaft 89 of the fixed side pressurizing mechanism 85. The pressure shafts 88 and 89 may be integrated.

Next, the process of processing a workpiece (rotating body 1) using the manufacturing apparatus 40 of the present embodiment will be described with reference to FIGS. 4 to 9 and FIG.
In the present embodiment, the workpiece (rotary body 1) in the state shown in FIG. 2 in which the groove 22 is formed by the lightening portion is used.

First, as shown in FIG. 4, both end portions of the shaft 10 of the workpiece (rotating body 1) are held by a fixed-side holder 42 and a movable-side holder 41 on a reference axis CL. At this time, the workpiece is set so that the disk-shaped mated member 20 is received by the fixed-side receiving portion 45 and lightly pressed to the fixed side by the movable-side pressing portion 44.
Note that the holding portion 44 is appropriately pressed in the axial direction by the coil spring 43, and the fitted member 20 is positioned in contact with the stopper portion 11.

Next, as shown in FIG. 5, the slide base drive mechanism 69 is driven so that the fixed-side holder 42 and the movable-side holder 41 approach each other. As a result, the disk-like mated member 20 is strongly pressed against the fixed side by the movable side pressing portion 44.
After positioning the workpiece, as shown in FIG. 6, the pressurizing portions 51 and 52 are brought into contact with both end faces 10 a and 10 b of the shaft 10, and the pressure F is applied to the shaft 10 by the right and left equal force. And pressurize toward the center.

Thereafter, rotation (in the direction of arrow R in the figure) is applied to the fixed-side holder 42 by the rotation drive mechanism 71, but the movable-side holder 41 also rotates in the same direction in synchronization. Therefore, the entire workpiece is rotated on the reference axis CL and is subjected to a back pressure load of the pressure F on the reference axis CL.
Here, the timing at which the pressure F is applied does not necessarily have to be before the rotational drive, but may be substantially simultaneously with the rotation or after the start of the rotation. In short, it suffices if the pressure parts 51 and 52 coincide with the reference axis CL before the bending is started.

  The pressurization start operation and the pressurization release operation of both the pressurization units 51 and 52 can be started by operating the operation panel only when both the holders 41 and 42 are at the reference axis CL, It is configured so that pressurization can not be started / released under other conditions. In the case of automatic processing, the pressurization start / pressurization release timing can be appropriately set by setting the pressurization conditions in advance.

  Next, as shown in FIG. 7, the workpiece swings the swinging table 64 starting from the swinging shaft 68 (S1) on the reference axis CL in a compressed state where rotation and back pressure load are applied. (Rotation in the direction of arrow A). This operation is performed by rotating the oscillating base 64 by the oscillating base driving cylinder 80 to a predetermined angle θ with the oscillating shaft 68 as a fulcrum (first tilt movement). Thereby, the axis CL1 of the holder 41 on the movable side is inclined and the shaft 10 is bent. The bending point S1 of the shaft 10 at this time is formed to substantially coincide with the swing shaft 68 in plan view (FIG. 17).

  By this bending, a compressive force and a tensile force are alternately applied in the cross section of the shaft 10 in the bent region and the vicinity thereof, and the plastic deformation is sequentially performed at a portion between the fixed side holder 42 and the movable side holder 41. And the action of the pressure F (back pressure load) is applied, the shaft diameter is enlarged from the bending point S1, and the enlarged portion 13 is deformed.

Details of the enlargement process will be described in detail with reference to FIG.
The initial state of this enlargement is shown in FIG. Note that during the manufacturing process shown in FIG. 14, pressure F is applied to both end faces 10 a and 10 b of the shaft 10.
In the initial state of the enlargement process, as shown in FIG. 14, the axis CL1 of the holder 41 on the movable side is the bending point S1 (the initial swing center, which coincides with the swing shaft 68. In this specification, It is in a state where it is inclined by a predetermined angle θ with respect to the reference axis CL from the point of reference P (also expressed as Ps, Pn, P1, P2). The bending point S1 is located at a bending point start point Ps on one end side (left side in FIG. 14A) of the insertion hole 21 of the fitted member 20, and moves along the reference axis CL by the subsequent operation. .

The movement of the bending point S1 is gradually rotated in a predetermined direction (in the direction of arrow E in the figure) by driving the top stage drive cylinder 75 with the top stage 66 serving as a fulcrum at another swing center Z. Let This movement is performed at a moving speed at which the shaft 10 can be enlarged.
By this movement, the bending point S1 continuously moves to the position of the bending point final point Pn as shown in FIG. In this way, the enlarged portion 13 is formed with a width sufficient to cover the width of the insertion hole 21 by the movement of the bending point S1 where enlargement is performed.
After the formation of the enlarged portion 13 is finished, the movable side axis line CL1 is returned to coincide with the reference axis line CL (returned to the position shown in FIG. 8).

After the enlarged portion 13 is formed, the axis 41 of the movable holder 41 is returned to coincide with the reference axis CL while the rotation of the holders 41 and 42 is maintained (see FIG. 8). Thereafter, the pressure F on the shaft 10 is released and the holder rotation is also stopped.
Note that the timing for releasing the pressure F applied to the shaft 10 may be the same as, before, or after the stop of the rotation of the holder.

  Finally, as shown in FIG. 9, the movable side holder 41 is operated so as to be separated from the fixed side holder 42, and then the interval between the holders is increased, and the workpiece is taken out of the holder. A series of manufacturing steps is completed.

  As shown in FIG. 10, the rotating body 1 manufactured as described above has a widened enlarged portion 13 that is greatly enlarged in the groove 22 of the inner peripheral surface 21 a. The rotating body 1 in which the enlarged portion 13 is also formed on the outside is manufactured.

Hereinafter, the operation in the manufacturing process will be described.
In the present embodiment, the groove 22 is formed in the insertion hole 21 of the fitted member 20, so that the shaft surface bites into the groove when the shaft 10 is enlarged. As a result, the contact area increases, and the shaft 10 bites into the groove 22 to cause meshing and increase the coupling force.
In the present embodiment, since the lightening portion for the purpose of reducing the weight is used, it is not necessary to provide a special groove, so there is no need to increase the number of manufacturing steps. Further, since the groove 22 is formed over the entire circumference of the inner peripheral surface of the insertion hole 21, the fitting force is increased uniformly in the entire axial direction of the shaft, and the fitting force in the axial direction and the fitting force in the rotational direction are increased. Can do.

Moreover, although the groove | channel 22 is comprised widely, the formation width of the enlarged part 13 can be adjusted freely by moving a bending point, and the wide and enlarged part 13 can be formed easily.
Further, in the workpiece, since the shaft 10 is provided with the stopper portion 11, positioning of the fitted member 20 with respect to the shaft 10 does not need to be performed using a jig or the like and can be positioned with high accuracy. The enlarged portion can be surely aligned with the groove 22 and the fitting accuracy can be increased.

Further, in manufacturing the rotating body 1 by the enlarged portion forming method, the deformation amount of the shaft 10 and the magnitude of the pressure F (back pressure load) are shown in FIG. As can be seen from FIG. 19, cracks are likely to occur in the shaft 10 as the deformation increases. On the other hand, as the pressure F (back pressure load) on the shaft 10 increases, the area where no cracks occur increases.
That is, the boundary line L between the generation of the crack and the region where the crack does not occur is inclined to the right, and the region where the crack is not generated moves to the larger deformation side.
Therefore, in the present embodiment, since the pressurization timing can be freely controlled by directly applying the pressurization F (back pressure load) to the end faces 10a, 10b of the shaft 10, a sufficient amount of deformation of the shaft 10 (enlargement) Amount) and a region where no crack is generated (GS region indicated by hatching in the drawing) can be easily and reliably processed.
This is because, when the required deformation amount α is set as the necessary deformation amount α in the specific shaft 10, if the machining process is performed with the back pressure load set to the necessary pressure Px or more, the large enlarged portion 13 Formation can be performed in a preferable state without cracks.

(Second Embodiment)
Hereinafter, a second embodiment according to the present invention will be described with reference to FIG.
Note that the reference numerals in FIG. 11 denote the same components as those in the first embodiment described above, and a description thereof will be omitted as appropriate, and the manufacturing method is the same as in the first embodiment. Description is omitted.
The rotating body 1A shown in FIG. 11 has a structure in which a plurality of grooves 22 are provided on the inner peripheral surface 21a. And this groove | channel 22 is comprised cyclically | annularly over the perimeter of the internal peripheral surface 21a. According to such a configuration, the fitting force between the shaft 10 and the fitted member 20 can be further increased over the entire circumference of the inner circumferential surface 21a.
When manufacturing the rotating body 1A of the present embodiment, the moving speed of the bending point S1 and the magnitude of the pressure F are changed and controlled in consideration of the size (width), depth and position of the groove 22. Also good.

(Third embodiment)
Hereinafter, a third embodiment according to the present invention will be described with reference to FIG.
Note that the reference numerals in FIG. 12 denote the same components as those in the first embodiment described above, and a description thereof will be omitted as appropriate, and the manufacturing method is the same as in the first embodiment. Description is omitted.
The rotating body 1B shown in FIG. 12 has a structure having a groove 22 formed in a spiral shape on the inner peripheral surface 21a. Accordingly, the groove 22 can be configured to have a long overall length on the inner peripheral surface 21a, and the fitting force between the shaft 10 and the fitted member 20 can be improved both in the axial direction and in the rotational direction.

(Fourth embodiment)
Hereinafter, a fourth embodiment according to the present invention will be described with reference to FIG.
The reference numerals in FIG. 13 denote the same components as those in the first embodiment described above, and a description thereof will be omitted as appropriate, and the manufacturing method is the same as in the first embodiment. Description is omitted.
The rotating member to be fitted 20 shown in FIG. 13 has a structure having a large number of grooves 22 formed intermittently in the circumferential direction of the inner peripheral surface 21a. According to this structure, the fitted member 20 and the shaft 10 can increase the fitting strength in the circumferential direction of the shaft 10 in addition to the fitting strength in the axial direction of the shaft 10.

(Fifth embodiment)
Hereinafter, a fifth embodiment according to the present invention will be described with reference to FIG. In FIG. 15, the same reference numerals are given to the same constituent elements as those in the first embodiment, and the manufacturing method will be described by omitting the same parts as in the first embodiment as appropriate.

FIG. 15 in the present embodiment illustrates a method of inclining the axis line CL1 and a method of moving the bending point S1 in the enlargement process of the shaft 10.
FIG. 15 (a) shows an initial state of the enlargement of the shaft 10. FIG.
In the present embodiment, as shown in FIG. 15, when the axis CL <b> 1 of the movable holder 41 is inclined by a predetermined angle θ, the bending point S <b> 1 (initial swing center) is the insertion hole 21 of the fitted member 20. Is positioned at the first point P1 of the bending point start position on one end side (left side in the figure).

Thereafter, the bending point S1 is driven by the top stage drive cylinder 75 so that the top stage 66 quickly rotates in a predetermined direction (the direction of arrow E in the figure) with the other swing center Z (virtual fulcrum) as a fulcrum. . The bending point S1 moves to the second point P2 by this quick operation (operation in which the enlargement hardly occurs). That is, as shown in FIG. 15B, the enlargement process of the shaft 10 is performed at two positions of the first point P1 and the second point P2. Therefore, the enlarged portion 13 can be intensively enlarged at two specific points in the width direction of the insertion hole 21, and can be effectively enlarged.
Further, in the present embodiment, the stopper portion 11 in the first embodiment is not provided. Therefore, the enlarged portion 13 can be formed outside the insertion hole of the fitted member 20 (see FIG. 15B) by setting the interval between the two positions of the first point P1 and the second point P2. .
Here, the quick movement in which the enlargement hardly occurs is not a particularly specified speed, and is that the action due to the enlargement does not substantially occur during the movement of the bending point. The material is appropriately set depending on the material, bending angle, rotational speed, pressure F, and the like.

As mentioned above, each said embodiment demonstrated the enlarged part formation method in the rotary body which consists of a hollow shaft and a disk-shaped sheave. However, the present invention is not limited to this, and for example, even when the shaft is solid, the member to be fitted can be applied to a member other than the sheave.
Further, in each of the above embodiments, a method of tilting one of the movable side holders as a movable side holder (rotating operation in the direction of arrow A of the holder 41 in FIG. 3) is adopted, but the present invention is not limited to this. For example, in addition to the movement of the holder 41 in the direction of arrow A in FIG. 3, the movement of the holder 41 in the direction perpendicular to the reference axis CL (the direction of arrow B), the orthogonality of the holder 42 to the reference axis CL (in the direction of arrow C) A method of moving the bending point S1 (P) and an apparatus configured to be able to perform this may be used by appropriately combining the movement operation of the holder 42 and the rotation operation (in the direction of arrow D) of the holder 42 with respect to the reference axis CL.

DESCRIPTION OF SYMBOLS 1, 1A, 1B, 1C Rotating body 10 Axis 11 Stopper part 13 Enlarged part 20 Fit member 21 Insertion hole 21a Inner peripheral surface 22 Groove 40 Manufacturing apparatus 41, 42 Holder 41a Movable side holder unit 42a Fixed side holder unit 51, 52 Pressurizing part 68 (S1) Oscillating shaft (bending point)
CL Reference axis P (S1) Bending point S1 Initial swing center Z Other swing center (virtual fulcrum)

Claims (14)

In a state where the metal shaft (10) is inserted into the insertion hole (21) of the fitted member (20) and the shaft (10) is fitted into the insertion hole (21), the shaft (10) Is held on the holder (41, 42) and rotated on the held reference axis (CL), and the fitted portion is placed at a predetermined bending point (P) with respect to the reference axis (CL). In the enlarged part forming method of increasing the diameter of the shaft (10) by bending and fixing the fitted member (20) and the shaft (10),
A method for forming an enlarged portion, wherein the diameter of the shaft (10) is increased while pressurizing both end faces of the shaft (10).   The pressurization to both end faces of the shaft (10) is performed via a pressurizing part (51, 52) that operates independently of the operation of the holder (41, 42). 2. A method for forming an enlarged portion according to 1.   The press of the said axis | shaft (10) by the said pressurization part (51, 52) is via the holder opening (41k, 42k) which open | releases the both end surfaces of the said axis | shaft (10), The Claim 2 characterized by the above-mentioned. The method for forming an enlarged portion as described.   4. The enlarged portion forming method according to claim 2, wherein a central axis of the pressurizing unit (51, 52) is always aligned with a rotation center of the holder (41, 42).   The enlarged portion forming method according to any one of claims 2 to 4, wherein the pressing portion (51, 52) is rotated by following the rotation of the holder (41, 42).   The enlarged part forming method according to any one of claims 2 to 5, wherein the pressing from the both end faces to the shaft (10) by the pressing part (51, 52) is uniformly performed. .   The pressurizing part (51, 52) contacts and separates the both end surfaces of the shaft (10) when both the holders (41, 42) are located on the same axis. The enlarged part forming method according to any one of claims 2 to 6. In a state where the metal shaft (10) is inserted through the insertion hole (21) of the fitted member (20), a pair of holders (41, 42) for holding the shaft (10) are provided. 41, 42) moving the portion corresponding to the insertion hole (21) to bend at the bending point (P) while rotating the shaft (10) about its reference axis (CL), In the manufacturing apparatus for increasing the diameter of the shaft (10) and fixing the fitted member (20) and the shaft (10),
The manufacturing apparatus (40) characterized by including the pressurization part (51, 52) which can pressurize both the end surfaces (10a, 10b) of the said axis | shaft (10).   The pressure parts (51, 52) for applying pressure to both end faces (10a, 10b) of the shaft (10) are configured to operate independently of the operation of the holder (41, 42). The manufacturing apparatus according to claim 8.   Holder openings (41k, 42k) that enable pressing of the shaft (10) by the pressurizing portions (51, 52) are configured to open both end surfaces (10a, 10b) of the shaft (10). The manufacturing apparatus according to claim 8, wherein the manufacturing apparatus is provided.   The pressurizing portions (51, 52) are configured such that, on both sides of the bending point (P), the respective central axes coincide with the respective rotation axes of the both holders (41, 42). The manufacturing apparatus according to any one of claims 8 to 10, wherein the manufacturing apparatus is provided.   The manufacturing method according to any one of claims 8 to 11, wherein the pressurizing part (51, 52) is configured to rotate following the rotation of the holder (41, 42). apparatus.   The said pressurization part (51, 52) was comprised so that the pressurization from the both end surfaces to the said axis | shaft (10) might become equal, The any one of Claims 8-12 characterized by the above-mentioned. Manufacturing equipment.   In the pressurizing unit (51, 52), the contact operation and the separation operation with respect to both end faces of the shaft (10) are performed when both the holders (41, 42) are located on the same axis. The manufacturing apparatus according to claim 8, wherein the manufacturing apparatus is configured as follows.

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