Patent ID: 12186793

DETAILED DESCRIPTION

However, when a member subjected to the thin-wall working is to be used for a shaft, the strength (deformation resistance) of the member may decrease by a thin-walled amount, and may be difficult to withstand the actual usage environment.

Additionally, there is one having a flange portion for the shaft. It is known that even in a case where a cylindrical base material is machined to form the flange portion, an adjacent portion of the flange portion is thin-walled, which causes a decrease in strength.

It is desirable to provide a spinning device and a spinning method capable of easily forming a flange portion while maintaining the wall thickness of a base material when the flange portion is formed in a base material having a tubular shape.

According to the present invention, when the flange portion is formed, the large-diameter portion is pressed and deformed in the center axis direction of the base material. Accordingly, the large-diameter portion is partially crushed and reduced in diameter to become a diameter-reduced portion. Additionally, when a part of the large-diameter portion becomes the diameter-reduced portion, a surplus of volume is generated in the large-diameter portion by that amount. This surplus is raised and deformed in the direction away from the center axis of the base material to become the flange portion.

Additionally, as previously mentioned, the large-diameter portion of the base material is pressed along the center axis of the base material. Such pressing allows the wall thickness of the base material to be increased or almost the same. Accordingly, the wall thickness in the formed product obtained from the base material is not reduced as much as possible, and is maintained in a state close to constant with the size of the wall thickness in the base material.

Hereinafter, a spinning device and a spinning method of the present invention will be described in detail on the basis of preferred embodiments shown in the accompanying drawings.

One Embodiment

Hereinafter, one embodiment of the spinning device and the spinning method of the present invention will be described with reference toFIGS.1to8. In addition, in the following, for convenience of explanation, three axes perpendicular to each other are set to an X-axis, a Y-axis, and a Z-axis. As an example, an XY plane including the X-axis and the Y-axis is horizontal, and the Z-axis is vertical. Additionally, inFIGS.1to6(the same applies toFIGS.9and10), an upper side may be referred to as “up (or upper)” and a lower side may be referred to as “down (or lower)”.

As shown inFIGS.1to4, the spinning device1includes a rotation support unit2, a machining unit3, a first moving mechanism unit4, and a second moving mechanism unit5. The spinning device1can form a base material9to obtain a formed product9C from the base material9. Then, the formed product9C is used, for example, as a shaft.

Additionally, as shown inFIG.7, the spinning device1includes a control unit8electrically connected to the rotation support unit2, the first moving mechanism unit4, and the second moving mechanism unit5.

As shown inFIG.8, the spinning device1can execute the spinning method of the present invention, that is, a rotation process and a machining process in order. Additionally, in the machining process, a first forming process (small-diameter portion forming process) and a second forming process (flange portion forming process) are executed in order.

The base material9is a member having a cylindrical shape (circular tubular shape) in the present embodiment. In addition, the base material9is not limited to the member having a cylindrical shape as long as the base material has a tubular shape. Additionally, the base material9is made of a metal material such as carbon steel for machine structure, aluminum, stainless steel and the like.

The base material9has a state of a primary base material9A shown inFIG.1and a state of a secondary base material9B shown inFIGS.2and3. Then, the base material9become the formed product9C shown inFIG.4via the state of the secondary base material9B from the state of the primary base material9A. The formed product9C is used as a shaft.

The size of the outer diameter and the inner diameter of the primary base material9A is constant in the direction of a center axis O9. Therefore, the wall thickness (thickness of the wall portion) t9of the base material9, that is, the size (value) obtained by subtracting the inner diameter from the outer diameter is also constant in the direction of the center axis O9. As will be described below, the wall thickness t9is maintained constant as it is until the formed product9C is obtained. In addition, the “constant” will be described below and defined.

The secondary base material9B has a large-diameter portion91and a small-diameter portion92disposed adjacent to each other in the direction of the center axis O9. The large-diameter portion91and the small-diameter portion92have different outer diameter and inner diameter sizes. In addition, a radius difference between the outer diameters of the large-diameter portion91and the small-diameter portion92is not particularly limited, but is preferably, for example, the wall thickness t9or more, and more preferably 1 time or more and 2 times or less the wall thickness t9(the same applies to a difference in inner diameter). Accordingly, for example, the forming of the flange portion93in the second forming process becomes easy. Additionally, this contributes to making the wall thickness t9constant until the secondary base material9B becomes the formed product9C.

The rotation support unit2can rotatably support the machining unit3and the base material9relative to each other around the center axis O9. Accordingly, the rotation process is performed. In the present embodiment, the rotation support unit2is configured to rotate the base material9around the center axis O9with respect to the machining unit3.

As shown inFIGS.1to4, the rotation support unit2has a chuck21and a motor23.

The chuck21holds one end side of the base material9, that is, a positive side in an X-axis direction. Accordingly, the base material9is cantilevered in a posture in which the center axis O9is parallel to the X-axis.

The motor23is connected to the chuck21. As the motor23operates, the power thereof is transmitted to the chuck21. Accordingly, the base material9can be rotated around the center axis O9. In addition, in the spinning device1, the rotation speed of the motor23can be changed by adjusting the voltage applied to the motor23.

The machining unit3can perform plastic working on the base material9. Accordingly, the machining process is performed. The machining unit3includes a first forming section6and a second forming section7.

The first forming section6is a small-diameter portion forming section that is used in the first forming process to form the small-diameter portion92in the primary base material9A. In the first forming process, the secondary base material9B is obtained.

The second forming section7is a flange forming section that is used in the second forming process to form the flange portion93in the secondary base material9B. In the second forming process, the formed product9C is obtained.

In addition, the configurations of the first forming section6and the second forming section7will be described below.

As shown inFIGS.1and2, the first moving mechanism unit4is a mechanism that independently moves the first forming section6in the X-axis direction (horizontal direction) and a Z-axis direction (vertical direction), respectively. The configuration of the first moving mechanism unit4is not particularly limited, and may be, for example, a configuration having a linear motion unit41and a motor42.

The linear motion unit41is a portion that is connected to the first forming section6and moves the first forming section6straight in a predetermined direction, and is constituted by, for example, a linear guide, a ball screw, and the like.

The motor42is connected to the linear motion unit41. As the motor42operates, the power thereof is transmitted to the first forming section6via the linear motion unit41. Accordingly, the first forming section6can be moved. In addition, in the spinning device1, by adjusting the voltage applied to the motor42, the rotation speed of the motor42can be changed to change the movement speed of the first forming section6.

As shown inFIGS.3and4, the second moving mechanism unit5is a mechanism that independently moves the second forming section7in the X-axis direction (horizontal direction) and the Z-axis direction (vertical direction), respectively. The configuration of the second moving mechanism unit5is not particularly limited, and may be, for example, a configuration having a linear motion unit51and a motor52.

The linear motion unit51is a portion that is connected to the second forming section7and moves the second forming section7straight in a predetermined direction, and is constituted by, for example, a linear guide, a ball screw, and the like.

The motor52is connected to the linear motion unit51. By operating the motor52, the power thereof is transmitted to the second forming section7via the linear motion unit51. Accordingly, the second forming section7can be moved. In addition, in the spinning device1, by adjusting the voltage applied to the motor52, the rotation speed of the motor52can be changed to change the movement speed of the second forming section7.

As shown inFIG.7, the control unit8is electrically connected to the rotation support unit2, the first moving mechanism unit4, and the second moving mechanism unit5, and can control the operation thereof. The control unit8has a CPU81and a storage unit82. The CPU81can execute, for example, a control program stored in advance in the storage unit82. The control program includes, for example, programs for controlling the operating conditions (operation timing) of the rotation support unit2, the first moving mechanism unit4, and the second moving mechanism unit5to form the base material9into the formed product9C.

As previously mentioned, the machining unit3includes the first forming section6and the second forming section7. The first forming section6is a small-diameter portion forming section that forms the small-diameter portion92in the primary base material9A in the first forming process. The second forming section7is a flange forming section that forms the flange portion93in the secondary base material9B in the second forming process.

As shown inFIGS.1and2, the first forming section6has a first roller(roller)61and a first pivoting support portion62that pivotably supports the first roller61. In the present embodiment, two sets of the first roller61and the first pivoting support portion62are disposed one above the other. Accordingly, the small-diameter portion92can be formed stably and rapidly.

In addition, the number of sets of the first roller61and the first pivoting support portion62is not limited to two, and may be, for example, one or three or more. Additionally, since each set has the same configuration except that the disposition spot is different, the configuration of one lower set will be described representatively.

The first pivoting support portion62has a base portion621and a shaft member622.

The base portion621is connected to the linear motion unit41of the first moving mechanism unit4.

The shaft member622has a columnar shape parallel to the center axis O9of the primary base material9A, that is, the X-axis, and is cantilevered by the base portion621. Additionally, the shaft member622is connected to a central portion of the first roller61.

The first roller61has a disk shape, and a center axis thereof is disposed parallel to the X-axis. The first roller61has a constant outer diameter portion611and a protrusion portion612.

The constant outer diameter portion611is a portion where the outer diameter of the first roller61is constant in the X-axis direction.

The protrusion portions612are disposed adjacent to each other on the positive side in the X-axis direction with respect to the constant outer diameter portion611. The protrusion portion612protrudes in a direction away from the center axis of the first roller61, that is, outward, and is provided in a ring shape along an outer peripheral portion of the first roller61.

A top613of the protrusion portion612is rounded, and a radius R613(seeFIG.5) thereof is not particularly limited, but for example, the wall thickness t9or more is preferable, and a wall thickness of 1 time or more and 3 times or less of the wall thickness t9is more preferable. Thereby, a radius difference in outer diameter between the large-diameter portion91and the small-diameter portion92can be set in the above numerical range. Additionally, the outer diameter of the top613is the maximum outer diameter of the first roller61.

When the small-diameter portion92is formed in the primary base material9A, first, as shown inFIG.1, the first roller61is brought into a state of being separated from the primary base material9A to a negative side in the X-axis direction. Then, the rotation support unit2is operated to bring about a state in which the primary base material9A is rotated. This rotational state is maintained until the forming of the small-diameter portion92is completed.

Next, as shown inFIG.2, the first roller61is brought close to the primary base material9A. Then, while the top613of the protrusion portion612is brought into contact with an outer peripheral portion of the primary base material9A and moved in the direction (X-axis direction) of the center axis O9, the outer peripheral portion is pressed toward the center axis O9side at the top613. Accordingly, the outer diameter and the inner diameter of the other end portion of the primary base material9A, which is the small-diameter portion92of the secondary base material9B, that is, an end portion (part) on the negative side in the X-axis direction, can be collectively reduced and deformed (seeFIG.5). By this deformation, the small-diameter portion92can be formed, and the secondary base material9B can be obtained. After that, the first forming section6is retracted from the secondary base material9B.

In addition, as shown inFIG.5, the outer peripheral portion of the primary base material9A is rounded such that a portion (step portion)94between the large-diameter portion91and the small-diameter portion92follows the shape of the top613.

Additionally, since the outer diameter and the inner diameter of the primary base material9A are collectively reduced as mentioned above, the wall thickness t9in the secondary base material9B is maintained to be constant with the size of the wall thickness t9in the primary base material9A. Here, the “constant” means that the wall thickness t9after forming is within a range of 60% or more and 120% or less of the wall thickness t9before forming (the same applies hereinafter).

As previously mentioned, the first roller61is rotatably supported around an axis parallel to the center axis O9. Since the small-diameter portion92is formed parallel to the center axis O9, it is preferable that the first roller61also rotates about an axis parallel to the center axis O9. In addition, the rotation axis of the first roller61may be inclined by a predetermined angle with respect to the axis parallel to the center axis O9within a range in which the first roller61can exhibit the function thereof.

Additionally, the first roller61is an idle roller. Accordingly, when the protrusion portion612of the first roller61is brought into contact with the outer peripheral portion of the primary base material9A, the first roller61follows the rotation of the primary base material9A, that is, rotate in synchronization without difficulty. Thus, the small-diameter portion92can be accurately formed.

The diameter (maximum outer diameter) of the first roller61is not particularly limited, but is, for example, preferably 1 time or more and 10 times or less and more preferably 4 times or more and 8 times or less the outer diameter of the primary base material9A (large-diameter portion91). Accordingly, the outer peripheral portion of the primary base material9A can be pressed toward the center axis O9side without excess or deficiency by the top613of the protrusion portion612, which contributes to rapid forming of the small-diameter portion92.

As shown inFIGS.3and4, the second forming section7has a second roller (roller)71and a second pivoting support portion72that pivotably supports the second roller71. In the present embodiment, two sets of the second roller71and the second pivoting support portion72are disposed one above the other. Accordingly, the flange portion93can be formed stably and rapidly.

In addition, the number of sets of the second roller71and the second pivoting support portion72is not limited to two, and may be, for example, one or three or more. Additionally, since each set has the same configuration except that the disposition spot is different, the configuration of one lower set will be described representatively.

The second pivoting support portion72has a base portion721and a shaft member722.

The base portion721is connected to the linear motion unit51of the second moving mechanism unit5.

The shaft member722has a columnar shape parallel to the Z-axis and is cantilevered by the base portion721. Additionally, the shaft member722is connected to a central portion of the second roller71.

The second roller71has a disk shape, and a center axis thereof is disposed parallel to the Z-axis. The second roller71has a constant outer diameter portion711, a convexly curved portion712, and a tapered portion713.

The constant outer diameter portion711is a portion where the outer diameter of the second roller71is constant in the Z-axis direction. The outer diameter of the constant outer diameter portion711is the maximum outer diameter of the second roller71.

The convexly curved portion712is disposed on an upper side of the constant outer diameter portion711. The convexly curved portion712is rounded and overhangs, and a radius R712(seeFIG.6) thereof is not particularly limited, but is preferably the same as, for example, the radius R613of the top613. Accordingly, when the large-diameter portion91is pressed in the direction of the center axis O9by the convexly curved portion712as described below, it is possible to prevent a situation in which a rounded portion94between the large-diameter portion91and the small-diameter portion92may be deformed unintentionally to hinder the forming of the flange portion93.

The tapered portion713is disposed between the constant outer diameter portion711and the convexly curved portion712, respectively. As shown inFIG.6, each tapered portion713is a portion where the outer diameter of the second roller71gradually increases toward the constant outer diameter portion711side. In addition, a portion drawn by the alternate long and short dash line inFIG.6is overlappingly shown by assuming the state ofFIG.5.

When the flange portion93is formed in the secondary base material9B, first, as shown inFIG.3, the second roller71is brought into a state of being separated from the secondary base material9B to the negative side in the X-axis direction. Then, the rotation support unit2is operated to bring about a state in which the secondary base material9B is rotated. This rotational state is maintained until the forming of the flange portion93is completed.

Next, as shown inFIG.4, the second roller71is brought close to the secondary base material9B. Then, while the second roller71is brought into contact with the outer peripheral portion of the small-diameter portion92and moved in the direction (X-axis direction) of the center axis O9, the large-diameter portion91is pressed in the direction of the center axis O9, that is, toward the positive side in the X-axis direction by the convexly curved portion712. Accordingly, the large-diameter portion91is partially crushed and reduced in diameter to be a diameter-reduced portion92. Additionally, when a part of the large-diameter portion91becomes the diameter-reduced portion92, a surplus of volume is generated in the large-diameter portion91by that amount. This surplus is raised and deformed in the direction away from the center axis O9. Then, the raised portion reaches the constant outer diameter portion711and the tapered portion713and is adjusted to the shape of the flange portion93(seeFIG.6). Accordingly, the flange portion93can be formed at a boundary portion of the large-diameter portion91with the small-diameter portion92, that is, between the large-diameter portion91and the small-diameter portion92, to obtain the formed product9C. After that, the second forming section7is retracted from the formed product9C.

Additionally, as described above, in the secondary base material9B, the large-diameter portion91is pressed toward the positive side in the X-axis direction. Such pressing allows the wall thickness t9to decrease (change). Accordingly, the wall thickness t9in the formed product9C obtained from the secondary base material9B is not reduced as much as possible, and is maintained to be constant with the size of the wall thickness t9in the secondary base material9B. Here, the “constant” is the same as described above.

As described above, according to the spinning device1(spinning method), when the flange portion93is formed in the base material9, the flange portion93can be easily formed while maintaining the wall thickness t9of the base material9. Accordingly, the formed product9C is prevented from being lowered in strength (mechanical strength) due to a decrease in the wall thickness t9, and thus can sufficiently withstand the actual usage environment used as a shaft.

As previously mentioned, the second roller71is rotatably supported around the axis perpendicular to the center axis O9, that is, around the Z-axis. Since the portion (a part of the large-diameter portion91) of the secondary base material9B pressed by the convexly curved portion712of the second roller71is parallel to the Z-axis direction, the center axis (rotation axis) of the second roller71is preferably parallel to the Z-axis. In addition, the rotation axis of the second roller71may be inclined by a predetermined angle with respect to an axis perpendicular to the center axis O9within a range in which the second roller71can exhibit the function thereof.

Additionally, the second roller71is an idle roller. Accordingly, when the second roller71is brought into contact with the outer peripheral portion of the secondary base material9B, the second roller71follows the rotation of the secondary base material9B, that is, rotates in synchronization without difficulty. Thus, the flange portion93can be accurately formed.

The diameter of the convexly curved portion712of the second roller71is not particularly limited, but is, for example, preferably 1 time or more and 10 times or less and more preferably, 4 times or more and 8 times or less the outer diameter of the large-diameter portion91. Accordingly, the large-diameter portion91can be pressed by the convexly curved portion712without excess or deficiency, which contributes to rapid forming of the flange portion93.

Another Embodiment

Hereinafter, another embodiment of the spinning device and the spinning method of the present invention will be described with reference toFIGS.9and10, but the differences from the above-mentioned embodiment will be mainly described, and descriptions of the same matters will be omitted.

The present embodiment is the same as the one embodiment except that the configuration of the rotation support unit2is different.

In the present embodiment, the rotation support unit2can take a first connection state in which the rotation support unit2is connected to the first forming section6and a second connection state in which the rotation support unit2is connected to the second forming section7, by a switching mechanism (not shown).

Then, in the first connection state, as shown inFIG.9, the rotation support unit2is in a state in which the base material9is fixed, and the first forming section6can be rotated around the base material9(center axis O9) with respect to the base material9. In addition, the first forming section6has two first rollers61, and inFIG.9, one first roller61is drawn representatively.

Additionally, in the second connection state, as shown inFIG.10, the rotation support unit2is in a state in which the base material9is fixed, and the second forming section7can be rotated around the base material9(center axis O9) with respect to the base material9). In addition, the second forming section7has two second rollers71, and inFIG.10, one second roller71is drawn representatively.

The rotation support unit2having the configuration as described above can also smoothly perform the rotation process, and thus can easily and accurately form the base material9.

Although the spinning device and the spinning method of the present invention have been described above with respect to the shown embodiments, the present invention is not limited thereto. Additionally, the respective parts constituting the spinning device can be replaced with optional components capable of exhibiting the same functions.

Additionally, optional components may be added. Additionally, the spinning device and the spinning method of the present invention may be a combination of two or more optional components (features) in each of the above-described embodiments.

It should be understood that the invention is not limited to the above-described embodiment, but may be modified into various forms on the basis of the spirit of the invention. Additionally, the modifications are included in the scope of the invention.