JP5342525B2 - Yoke shaft manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a yoke shaft which can secure a high strength as the yoke shaft and achieve a reduction of manufacturing cost and to provide the yoke shaft. <P>SOLUTION: The method of manufacturing the yoke shaft A1 includes the steps of: drawing an end side of a tube material 1 by allowing the diameter thereof to be smaller than that of the other end side; forming a shaft section A2 integrally on the end of the tube material 1; forming a female mold 1d of a spline along the inside of a peripheral wall on the end side of the tube material 1; forming a rectangular yoke forming section 1b integrally on the other end side of the tube material 1 by allowing the other end of the tube material 1 to be plastic deformed in a direction perpendicularly intersecting to a longitudinal direction; carrying out notch processing of a U-shaped notch portion 1e to the peripheral wall of the broad side opposite to the yoke forming section 1b; carrying out hole drilling of a round hole portion 1f to the peripheral wall of the narrow side opposite to the yoke forming section 1b; and forming a U-shaped yoke section A4 integrally on the other end side of the tube material 1. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

The present invention relates to a manufacturing method of a yoke shaft used for example in the telescopic mechanism which constitutes a steering device for a vehicle (called telescopic mechanism).

  Conventionally, as a method of manufacturing the shaft of the telescopic mechanism, for example, a step of forming one side portion of a pipe material into a small diameter shaft by drawing, and an unprocessed portion of the pipe material from the inner end side of the small diameter shaft portion A step of cold part ironing toward the outer end portion of the raw portion to form a key lock square groove portion, a step of squeezing the outer end portion of the raw portion of the pipe material to a small diameter, and There is a method of manufacturing a steering main shaft of Patent Document 1 including a step of forming an inner spline by machining on the inner periphery of the small-diameter shaft portion.

  However, a yoke part which is a joint of a universal joint is not formed at the end of the main shaft manufactured by the method of the patent document, and the yoke part must be integrally connected to the end of the main shaft. Don't be. In addition, since the main shaft and the yoke part are manufactured in separate steps and then the main shaft and the yoke part are integrally connected, not only the number of manufacturing steps is increased, but also the work of processing the main shaft and the yoke part. Takes time and effort. Further, when the yoke portion is welded to the end portion of the main shaft, the strength of the welded portion is weaker than that of the other portions, so that it is difficult to ensure the strength as the shaft.

Patent No. 3176113

An object of the present invention is to provide a yoke shaft manufacturing method capable of ensuring high strength as a yoke shaft and reducing the manufacturing cost.

The present invention relates to a method for manufacturing a yoke shaft comprising a shaft portion provided on one end side of a metal tube material and a yoke portion provided on the other end side of the tube material, wherein one end of the tube material is provided. The range from the side to the center is expanded in the radially outward direction, and the inner peripheral wall surface of the range is larger than the inner diameter of the inner peripheral wall surface on the other end side of the tube material. An arrow threading step for processing the pipe material to be thinner than the peripheral wall, a cutting step for cutting the outer peripheral surface of the pipe material by a desired thickness, and one end side of the pipe material at the other end. A drawing process of forming a shaft portion by drawing to a smaller diameter from the side and forming a spline in the longitudinal direction along the inner surface of the peripheral wall of the one end side of the pipe material, and on the other end side of the pipe material, The other end side is plastically deformed in a direction orthogonal to the longitudinal direction of the tube material to form a rectangular yaw. A molding step of a molded part, a notch mold of the U-shaped formed narrower than between the opposed surfaces of the narrow side wall opposite of the yoke forming part, with respect to the inside of the yoke forming part The first portion of the U-shaped notch is inserted to an insertion position where the first portion is sheared, and the corner corner outer surface of the one wide side peripheral wall is connected to the corner corner outer surface of the one wide side peripheral wall of the yoke forming portion. After pressing the pair of receiving molds that support the notched mold at an interval that allows passage of the notched mold, the one wide side peripheral wall that supports the notched mold with the pair of receiving molds Is moved from the inner side to the outer side in the shearing direction in the thickness direction, the first portion of the one wide side peripheral wall is notched in the thickness direction, and the notch mold is moved to the first portion in the notch portion. After inserting to the insertion position where the second part behind the part 1 is sheared, The one wide side peripheral wall is moved from the inside to the outside in the direction sheared in the thickness direction, and the second portion of the one wide side peripheral wall is notched in the thickness direction, so that the U-shaped cut An insertion position in which the U-shaped notch mold is entirely sheared in the U-shaped notch portion with respect to the inside of the yoke-molded portion while the notch portion is formed on the one wide side peripheral wall. And a pair of receiving molds that support the outer surface of the corner of the other wide side peripheral wall are allowed to pass through the notch mold on the outer surface of the corner of the other wide side peripheral wall of the yoke forming portion. The notched mold is moved from the inner side to the outer side in the direction in which the other wide side peripheral wall supported by the pair of receiving molds is sheared in the thickness direction. The part corresponding to the whole of the notch on the wide side peripheral wall of the A notch process in which the U-shaped notch portion is formed in the other wide side peripheral wall, and the yoke forming portion is formed on the narrow side peripheral wall facing the yoke forming portion. And a drilling step of forming a hole formed by penetrating the narrow side peripheral wall in the thickness direction.

  As an aspect of this invention, between the cutting step and the drawing step, an annealing step for performing an annealing treatment to remove distortion generated in the tube material, and a layer of a phosphoric acid compound on the entire surface of the tube material And a bonder process for performing a bond process for uniform formation.

  Further, as an aspect of the present invention, before the cutting step, the other end side of the tube material is plastically deformed in a direction perpendicular to the longitudinal direction of the tube material, and an elliptical shape is formed on the other end side of the tube material. A step of forming the yoke forming portion can be provided.

  The tube material is made of metal having a round shape formed with the same outer diameter and inner diameter from one end side toward the other end side, and formed with the same cross-sectional shape from the one end side toward the other end side. Composed of tubes.

The squeezing step can be composed of a rod-shaped or shaft-shaped stepped core and first and second squeezing devices provided with dies.
The molding step can be constituted by a fixed mold, a first molding apparatus including a mandrel, a rectangular mold, a wide mold, and a second molding apparatus including a narrow mold.

A notch process can be comprised with the notch apparatus provided with the U-shaped notch metal mold | die and the receiving metal mold | die.
The drilling step can be constituted by a drilling device provided with a drill for drilling.
A cutting process can be comprised with the cutting device provided with the cutting blade.

An annealing process can be comprised with the annealing apparatus provided with the annealing chamber for annealing a pipe raw material.
The bond process can be constituted by a bonder device having a bond chamber for bonding a pipe material.

  According to this invention, a single metal pipe material formed into a hollow shape is processed to produce a yoke shaft in which a shaft portion, a lower tube portion, and a yoke portion are integrally formed. The strength of the yoke shaft is not partially weakened, and high strength can be secured as the yoke shaft. Further, since the labor and work of machining each part of the yoke shaft separately or welding each part machined separately can be omitted, the work of manufacturing the yoke shaft can be performed easily and easily. Further, not only the time required for production is greatly shortened, but also the number of processes and parts at the time of production is reduced, so that the production cost can be reduced.

The perspective view which shows the yoke shaft manufactured with the yoke shaft manufacturing method. Explanatory drawing which shows the brewing process which forms a collar part in the one end side outer periphery of a pipe | tube raw material. Explanatory drawing which shows the arrow threading process which expands the inner peripheral surface of the one end side of a pipe | tube raw material to a large diameter. Explanatory drawing which shows the dropping process which removes the collar part of a pipe | tube raw material. Explanatory drawing which shows the 1st shaping | molding process which shape | molds the other end side of a pipe raw material. Explanatory drawing which shows the shaping | molding part cutting process which cuts the outer peripheral wall of a shaping | molding side. Explanatory drawing which shows the non-molding part cutting process which cuts the surrounding wall outer surface of a non-molding side. Explanatory drawing which shows the 1st drawing process which draws an unmolded side to a small diameter. Explanatory drawing which shows the annealing process which anneals uniformly the whole pipe | tube raw material. Explanatory drawing which shows the bond process which bond-processes the whole pipe | tube raw material uniformly. Explanatory drawing which shows the 2nd drawing process which draws a non-molding side front end to a small diameter. Explanatory drawing which shows the 2nd shaping | molding process which shape | molds a yoke shaping | molding part in a rectangular shape. Explanatory drawing which shows the trimming process which trims both ends of a pipe | tube raw material. Explanatory drawing which shows the notch process which processes a notch part in a yoke shaping | molding part. Explanatory drawing which shows the process sequence of the notch processed into a yoke formation part. Explanatory drawing which shows the drilling process which processes a hole part in a yoke shaping | molding part.

  FIG. 1 is a perspective view showing a yoke shaft A1 manufactured by the yoke shaft manufacturing method, FIG. 2 is an explanatory view showing a squeezing process for forming a flange portion 1a on one outer peripheral edge of the tube material 1, and FIG. FIG. 4 is an explanatory view showing an arrow passing process for expanding the inner peripheral surface of one end side of the pipe material 1 to a large diameter, FIG. 4 is an explanatory view showing a dropping process for removing the flange portion 1a of the pipe material 1, and FIG. FIG. 6 is an explanatory view showing a molding part cutting step of cutting the outer peripheral surface of the molding side, and FIG. 7 is an outer peripheral wall of the non-molded side. It is explanatory drawing which shows the unshaped part cutting process which cuts an outer surface.

  8 is an explanatory view showing a first drawing step for drawing the unformed side to a small diameter, FIG. 9 is an explanatory view showing an annealing step for uniformly annealing the entire tube material 1, and FIG. FIG. 11 is an explanatory view showing a bonding process for uniformly bonding the entire tube material 1, FIG. 11 is an explanatory view showing a second drawing process for drawing the unformed side tip to a small diameter, and FIG. 12 is a yoke forming part. FIG. 13 is an explanatory view showing a second aligning step for aligning both ends of the tube material 1, and FIG. 14 is an explanatory view showing a notch portion 1e in the yoke forming portion 1b. FIG. 15 is an explanatory diagram showing a processing procedure of the notch portion 1e to be processed into the yoke forming portion 1b, and FIG. 16 is processing the hole portion 1f in the yoke forming portion 1b. It is explanatory drawing which shows a drilling process.

As shown in FIG. 1, the yoke shaft A1 manufactured by the yoke shaft manufacturing method of the present embodiment has a shaft portion A2, a lower tube portion A3, and a U-shaped yoke portion A4 formed integrally. One shaft.
The shaft portion A2 is connected to a shaft (not shown) so as to be stretchable by spline fitting. Further, the yoke part A4 is rotatably connected to a shaft (not shown) by a universal joint.

  The yoke shaft manufacturing method of the present embodiment includes a squeezing process for forming a flange 1a on the outer peripheral edge of one end of a single metal tube material 1 formed in a hollow shape, and an inner periphery on one end side of the tube material 1 An arrow threading step for expanding the surface to a large diameter, a dropping step for cutting off the flange portion 1a of the tube material 1, a first forming step for forming the yoke forming portion 1b on the other end side of the tube material 1, and a yoke A molded part cutting process for cutting the outer peripheral surface of the molded part 1b, an unmolded part cutting process for cutting the outer peripheral surface of the unformed side cylindrical part 1c, and a first drawing process for drawing the cylindrical part 1c to a small diameter. And an annealing process for uniformly annealing the entire tube material 1, a bond process for uniformly bonding the entire tube material 1, and a second drawing process for drawing the tip side of the tubular portion 1c to a small diameter. And a second forming step of forming the yoke forming portion 1b into a rectangular shape, and cutting both ends of the tube material 1 A switching alignment process obtain, composed of a cutout step of notching a notch 1e to the yoke forming portion 1b, the hole making step for processing a hole 1f in the yoke forming unit 1b.

As shown in FIG. 2, the squeezing process includes a pressing die press device 2 including a fixed die 2a and a pressing die 2b.
In the pressing mold pressing device 2, after the metal tube material 1 is loaded in the stationary mold 2a (left side in the figure), the pressing mold pressing apparatus 2 is loaded in the stationary mold 2a by the pressing mold 2b having a convex pressing portion. One end side (upper end side in the figure) of the tube material 1 is pressurized in the longitudinal direction (or axial direction).
That is, the outer peripheral edge at the one end side of the tube material 1 is plastically deformed outward, and the annular flange 1a is integrally formed along the outer peripheral edge at the one end side of the tube material 1 (right side in the figure).

  After the drawing process is completed, the pressing mold 2b is separated from one end side of the tube material 1 and the tube material 1 is extracted from the fixed mold 2a. It is possible to shift to a threading process.

The tube material 1 is formed with the same outer diameter and inner diameter from one end side (upper end side in the figure) to the other end side (lower end side in the figure). And it is a round tube formed in the same cross-sectional shape from one end side toward the other end side.
In addition to the pressing die pressing device 2, the tube material 1 shown in FIG. 2 can be made using, for example, an impact pressing device, a cold die forging device, or the like.

Subsequently, after finishing the pipe material 1 in the drawing process, the arrowing process is performed in the next arrowing process.
In the next arrowing process, a method of processing the tube material 1 on which the flange 1a is formed in the drawing process in the stationary mold 3a of the arrowing apparatus 3 will be described.

As shown in FIG. 3, the arrow threading process includes an arrow threading device 3 including a fixed mold 3a, a presser mold 3b, and a mandrel 3c.
The arrow threading device 3 expands in the radial direction by plastically deforming the inner surface of the peripheral wall in the range from one end side to the center portion of the tube material 1 in which the flange portion 1a is formed in the unwinding step by the mandrel 3c, The inner surface of the peripheral wall in the range from one end side to the center of the tube material 1 is processed to have a larger diameter than the inner diameter of the inner surface of the other end side peripheral wall.

  That is, the tube material 1 on which the flange portion 1a is formed in the dredging process is loaded into the fixed mold 3a of the arrow passing device 3, and the flange portion 1a of the tube material 1 is loaded on the loading side flat surface of the fixed mold 3a. (The left side in the figure), the presser mold 3b waiting upward is moved in a direction facing the loading side flat surface of the fixed mold 3a, and the flange 1a of the tube material 1 is moved to the fixed mold. 3a and presser mold 3b are clamped and fixed (right side in the figure).

  Next, the rod-shaped or shaft-shaped mandrel 3c is moved from one end side (upper end side in the figure) to the other end side (lower end side in the figure) with respect to the inside of the tube material 1 sandwiched between the fixed mold 3a and the presser mold 3b. The inner wall of the tube material 1 is plastically deformed in the range from the inner wall of the one end side wall to the inner wall of the central portion while being press-fitted in the longitudinal direction toward the tube, and is radially directed from the axial center of the tube material 1 toward the outer periphery. Extend to

  At the time of expansion, since the peripheral wall in the range from one end side to the other end side of the tube material 1 is regulated to a constant outer diameter by the fixed mold 3a, the inner diameter of the one end side peripheral wall of the tube material 1 is 1 is plastically deformed so as to have a larger diameter than the inner diameter of the peripheral wall on the other end side.

  Thereby, the one end side peripheral wall of the tube material 1 is made thinner than the thickness of the peripheral wall in the range from the central peripheral wall to the other end side peripheral wall while the entire peripheral wall length of the tube material 1 is maintained at a constant outer diameter. It is formed. Further, due to plastic deformation of the tube material 1, the entire length of the tube material 1 is stretched in the longitudinal direction.

  After completion of the threading process, the mandrel 3c is extracted from the inside of the one end side of the tube material 1, the holding die 3b is released from the fixed die 3a and released, and then the tube material 1 is removed from the fixed die 3a. If extracted, the pipe material 1 in which the arrow thread has been completed can be transferred to the next dropping process.

In addition, the mandrel 3c of the arrow passing device 3 is fixed to the fixed die 3a and the presser foot while the tube material 1 in which the flange portion 1a is formed in the drawing process is loaded in the fixed die 2a of the pressing die press device 2. The pipe material 1 may be press-fitted into the tube material 1 sandwiched between the molds 3b so that the one end side peripheral wall of the tube material 1 is thinner than the thickness of the central part peripheral wall and the other end side peripheral wall.
Subsequently, after the processing of the tube material 1 is completed in the arrow passing process, the pipe material 1 is dropped and processed in the next dropping process.

As shown in FIG. 4, the dropping process includes a dropping device 4 having a cutting blade 4a.
The dropping device 4 cuts the flange portion 1a formed on the outer peripheral edge on one end side of the tube material 1 by the cutting blade 4a in the brewing process, and the entire length of the peripheral wall extending from one end side to the other end side of the tube material 1 Are cut into the same outer diameter from one end side to the other end side (left side in the figure).

  That is, the tube material 1 whose both ends are supported by a support means (not shown) is rotated at high speed in one direction (the direction indicated by the arrow in the drawing) around the axis of the tube material 1. At the same time, while moving the cutting blade 4 a pressed against the outer peripheral surface of the tube material 1 in the longitudinal direction along the outer peripheral surface of the tube material 1, the flange 1 a formed on the outer peripheral edge on one end side of the tube material 1 is moved. Remove by cutting (right side in the figure).

  After the crushing process is completed, the cutting blade 4a is separated from the outer peripheral edge on one end side of the tube material 1 and the support of the tube material 1 by the support means (not shown) is released, and then the tube material 1 that has been crushed is removed. It is possible to shift to the first molding step. Moreover, you may remove the collar part 1a of the pipe raw material 1 by shearing.

Subsequently, after the processing of the tube material 1 is completed in the dropping process, the forming is performed in the next first forming process.
In the post-process after the dropping process, a method of processing the tube material 1 so that the one end side and the other end side are turned upside down will be described.

As shown in FIG. 5, the first molding step includes a first molding device 5 including a fixed mold 5a and a mandrel 5b.
The first forming device 5 loads the tube material 1 from which the collar portion 1a has been cut off in the dropping process into the fixed mold 5a (left side in the figure), and then attaches the rod-shaped or shaft-shaped mandrel 5b to the fixed mold. The inside of the tube material 1 loaded in the mold 5a is press-fitted in the longitudinal direction from the other end side (upper end side in the figure) to the one end side (lower end side in the figure).
In addition, the peripheral wall in the range from the other end side of the tube material 1 to the central portion is plastically deformed outward in a direction perpendicular to the longitudinal direction of the tube material 1, and the tube material 1 is directed from the axial center to the outer periphery side. Expand radially (right side in the figure).

In other words, the peripheral wall in the range from the other peripheral wall to the central peripheral wall of the tube material 1 is narrower than the other opposing narrower than the wall thickness of one opposing wide side wall with the axial center of the tube material 1 as the center. Plastic deformation is performed so that the thickness of the side wall is increased.
Further, it is formed into an elliptical cross section in which the distance between the opposing narrow side peripheral walls is narrower than the distance between the one opposing wide side peripheral walls (horizontal of the yoke forming portion 1b shown in the upper left of FIG. 6). (See cross-sectional view).
As a result, an elliptical yoke forming portion 1b that becomes the yoke portion A4 of the yoke shaft A1 is integrally formed on the other end side of the tube material 1.

After the forming of the yoke forming portion 1b is completed, the mandrel 5b is extracted from the inside of the other end of the tube material 1, and the tube material 1 is extracted from the fixed mold 5a. It is possible to shift to the molding part cutting process.
Subsequently, after the forming of the tube material 1 is completed in the first forming step, cutting is performed in the next forming portion cutting step.

As shown in FIG. 6, the forming part cutting step includes a forming part cutting device 6 having a cutting blade 6a.
The forming part cutting device 6 cuts the outer peripheral surface (the dotted line portion on the left side in the figure) of the yoke forming part 1b of the tube material 1 formed in the first forming process with the cutting blade 6a. The outer peripheral surface of the yoke forming portion 1b in a range from the other end side peripheral wall to the central portion peripheral wall is processed so as to have the same diameter as the outer diameter of the one end side peripheral wall of the tube material 1.

  That is, the tube material 1 whose both ends are supported by a support means (not shown) is rotated at high speed in one direction (the direction indicated by the arrow in the drawing) around the axis of the tube material 1. At the same time, the cutting blade 6a pressed against the outer peripheral surface of the tube material 1 is moved in the longitudinal direction along the outer peripheral surface of the yoke forming portion 1b of the tube material 1 (left side in the figure).

The thickness of the outer peripheral wall facing the major axis direction of the yoke molded part 1b is projected outside the central peripheral wall or one end side peripheral wall of the tube material 1 without cutting the peripheral wall facing the minor axis direction of the yoke molded part 1b. Cut and remove as much as possible.
In short, while the inner peripheral wall surface of the yoke forming portion 1b is formed in an elliptical shape when viewed from the longitudinal direction, the entire peripheral wall length of the tube material 1 is cut so as to have the same outer diameter from one end side to the other end side. (Right side in the figure).

  Thereby, when the yoke forming portion 1b of the tube material 1 is formed in the second forming step to be described later, cracks and cracks are not generated in the yoke forming portion 1b, and the forming can be performed easily and easily. Further, it is possible to reduce the weight without reducing the strength of the yoke forming portion 1b.

After the cutting of the yoke forming portion 1b is completed, the cutting blade 6a is separated from the outer peripheral surface on the other end side of the tube material 1, and the support of the tube material 1 by the support means (not shown) is released, the tube material that has been cut. 1 can be transferred to the next unformed part cutting step.
Subsequently, after the cutting of the tube material 1 is completed in the forming part cutting process, the cutting process is performed in the next unformed part cutting process.

As shown in FIG. 7, the unformed part cutting step includes an unformed part cutting device 7 having a cutting blade 7a.
The unformed part cutting device 7 cuts the unformed side peripheral wall outer surface (the lower end side in the figure) of the tube material 1 that has not been cut in the formed part cutting process with the cutting blade 7 a, and the central part peripheral wall of the tube material 1. The peripheral wall in the range from the one end side peripheral wall to the one end side peripheral wall is processed so as to have a smaller diameter than the outer diameter of the other end side peripheral wall of the tube material 1.

  That is, the tube material 1 whose both ends are supported by a support means (not shown) is rotated at high speed in one direction (the direction indicated by the arrow in the drawing) around the axis of the tube material 1. At the same time, while the cutting blade 7a pressed against the outer peripheral surface of the tube material 1 is moved in the longitudinal direction along the outer peripheral surface at one end of the tube material 1, the outer surface of the peripheral wall of the unformed side tubular portion 1c of the tube material 1 Is removed by cutting so as to be smaller than the outer diameter of the peripheral wall on the other end side of the tube material 1 cut in the forming part cutting step (left side in the figure).

Thereby, the cylindrical part 1c used as the shaft part A2 of the yoke shaft A1 is integrally shape | molded by the one end side of the pipe raw material 1 (right side in the figure).
Further, when the cylindrical portion 1c of the pipe material 1 is drawn in a second drawing step described later, the central part peripheral wall and the one end side peripheral wall of the pipe raw material 1 are not cracked or cracked, and the drawing process is performed. Can be done easily and easily. Furthermore, it is possible to reduce the weight without reducing the strength of the cylindrical portion 1c. As a result, the weight of the yoke shaft A1 can be reduced.

After the cutting of the unformed part is completed, the cutting blade 7a is separated from the outer peripheral surface of the one end side of the tube material 1 and the support of the tube material 1 by the support means (not shown) is released, the tube material 1 after the cutting is completed. It is possible to proceed to the next first drawing process.
Subsequently, after the cutting of the tube material 1 is completed in the unformed part cutting process, the drawing process is performed in the next first drawing process.

As shown in FIG. 8, the first squeezing step includes a first squeezing device 8 composed of a stepped mandrel 8a and a die 8b.
The first squeezing device 8 has a stepped cored bar 8a from the yoke forming portion 1b side (the upper end side in the figure) of the tube material 1 inside the tube material 1 cut in the unformed portion cutting step. After the insertion, while the peripheral wall of the cylindrical portion 1c in the range from the one end side peripheral wall to the central peripheral wall of the tube material 1 is plastically deformed in the direction of diameter reduction by the die 8b, it is formed on the outer surface of the intermediate diameter portion 8d of the cored bar 8a. Press to draw to the desired diameter.

  A large-diameter portion 8c having the same diameter as the inner peripheral surface of the yoke forming portion 1b of the tube material 1 formed in the first forming step is formed on the upper end side of the cored bar 8a. Further, a portion extending from the central part to the lower end side of the cored bar 8a is formed with a smaller diameter than the large-diameter part 8c of the cored bar 8a, and the peripheral wall of the cylindrical part 1c is restricted to a smaller diameter than the large-diameter part 8c. An intermediate diameter portion 8d is formed.

  That is, the core bar 8a of the first drawing device 8 is directed from the yoke forming portion 1b side of the tube material 1 toward the tubular portion 1c side with respect to the inside of the tube material 1 processed in the unformed portion cutting step. Insert in the longitudinal direction (left side in the figure).

  The outer diameter of the large diameter portion 8c of the core metal 8a is pressed against the inner peripheral surface of the yoke forming portion 1b of the tube material 1, and the outer wall of the yoke forming portion 1b is formed by the first forming step. And restrict to the inner diameter. Further, the middle diameter portion 8 d of the cored bar 8 a is held at a position inserted in the longitudinal direction with respect to the axial center of the tube material 1.

  Thereafter, the die 8b is moved in the longitudinal direction from one end side toward the central portion along the outer peripheral surface of the tube material 1, and the peripheral wall of the cylindrical portion 1c is pivoted from the outer periphery side of the tube material 1 by the die 8b. Plastic deformation in the direction of diameter reduction toward the center.

At this time, the peripheral wall of the tubular portion 1c of the tube material 1 is pressed against the outer surface of the middle diameter portion 8d of the core metal 8a, and is regulated so as not to be narrowed down to a smaller diameter than the middle diameter portion 8d.
Accordingly, the peripheral wall of the tubular portion 1c of the tube material 1 is drawn to a smaller diameter than the large diameter portion 8c of the core metal 8a without drawing the other end side peripheral wall (the upper end side in the drawing) of the tube material 1. (Right side in the figure).

After the drawing is completed, the die 8b is extracted from the outer peripheral side of the other end of the tube material 1 and the cored bar 8a is pulled out from the other end side opening of the tube material 1, so that the drawn tube material 1 is completed. Can be transferred to the next annealing step.
Subsequently, after the drawing of the tube material 1 is completed in the first drawing process, an annealing process is performed in the next annealing process.

As shown in FIG. 9, the annealing process includes an annealing device 9 having an annealing chamber 9a for annealing.
The annealing apparatus 9 carries the pipe material 1 drawn in the first drawing step into the annealing chamber 9a with the door 9b opened, and then uniformly heats the whole pipe material 1 for annealing treatment. (See the arrow in the figure).

  In other words, by uniformly heating the entire tube material 1 carried into the annealing chamber 9a at an annealing high temperature, it is possible to remove the distortion of the tube material 1 that occurs when the tube material 1 is processed in a process before the annealing process. Moreover, it can prevent that a crack, a crack, etc. arise in the pipe raw material 1 when processing in the process after a bond process.

After the annealing process is completed, if the tube material 1 is taken out from the annealing chamber 9a by opening the door 9b, the tube material 1 after the annealing process can be transferred to the next bond process.
Subsequently, after the annealing process of the tube material 1 is completed by annealing, the bonding process is performed in the next bonding process.

As shown in FIG. 10, the bonder process includes a bonder device 10 having a bonder tank 10 a for performing a bondage process.
The bonder apparatus 10 immerses the pipe material 1 annealed by annealing in a phosphate coating solution 10b stored in a bonder tank 10a, so that the entire surface of the pipe material 1 (the inner surface and the outer surface of the peripheral wall). ) To uniformly form a phosphoric acid compound layer 10c (or film) (see an enlarged longitudinal sectional view shown in part a of FIG. 10).

  In other words, the entire surface of the tube material 1 is uniformly covered by the phosphoric acid compound layer 10c by a chemical reaction, so that rust is hardly generated on the surface of the tube material 1. Further, when the tube material 1 is processed in the steps after the bonder step, it is possible to prevent the processing mold from being damaged.

  After the bonding process is completed, if the tube material 1 is taken out from the phosphate coating solution 10b in the bonder tank 10a and washed with water, the tube material 1 that has been bonded is transferred to the next second drawing step. Can do.

In this embodiment, the zinc phosphate coating solution is used as the phosphate coating solution 10b. Alternatively, the phosphate coating solution 10b may be sprayed on the entire surface of the tube material 1 to be bonded.
Subsequently, after the bonding process of the tube material 1 is completed in the bonding process, the drawing process is performed in the next second drawing process.

As shown in FIG. 11, the second squeezing step includes a second squeezing device 11 composed of a stepped mandrel 11a and a die 11b.
The second squeezing device 11 is configured to insert a stepped core metal 11a from the other end side opening (the upper end side in the figure) of the tube material 1 into the tube material 1 that has been bonded in the bond process. Then, the tip side peripheral wall of the tubular portion 1c of the tube material 1 is pressed into the outer surface of the small diameter portion 11e of the core metal 11a while being plastically deformed in a direction in which the tube diameter is reduced by the die 11b, and is drawn to a desired diameter. .

  A large diameter portion 11c having the same diameter as the inner peripheral surface of the yoke forming portion 1b formed in the first forming step is formed on the upper end side of the core metal 11a. Further, an intermediate diameter portion 11d having the same diameter as the inner peripheral surface of the central portion of the tube material 1 is formed at the central portion of the core metal 11a.

  Further, the lower end side of the core bar 11a is formed with a smaller diameter than the middle diameter part 11d of the core bar 11a, and the tip side peripheral wall of the tubular part 1c of the tube material 1 is restricted to a smaller diameter than the middle diameter part 11d. A small diameter portion 11e is formed. Further, a male part 11f for processing a spline is formed on the outer peripheral surface of the small diameter part 11e along the inner surface of the one end side peripheral wall of the tube material 1.

  In other words, the metal core 11a of the second expansion device 11 is moved in the longitudinal direction from the opening on the other end side of the tube material 1 toward the opening on the one end side with respect to the inside of the tube material 1 subjected to the bonding process. Insert (left side in the figure).

  The outer surface of the large-diameter portion 11c of the core metal 11a is pressed against the inner peripheral surface of the yoke forming portion 1b of the tube material 1, and the outer surface of the middle-diameter portion 11d of the core metal 11a is pressed against the inner peripheral surface of the center portion of the tube material 1. The yoke forming portion 1b of the material 1 is restricted to the outer diameter and inner diameter processed in the first forming step and the first drawing step. Further, the small diameter portion 11 e of the core metal 11 a is held at a position inserted in the longitudinal direction with respect to the axial center of the tube material 1.

  Thereafter, the die 11b is moved in the longitudinal direction from one end side toward the central portion along the outer peripheral surface of the tube material 1, while the tip side peripheral wall of the cylindrical portion 1c is moved to the outer periphery side of the tube material 1 by the die 11b. The plastic is deformed in the direction of diameter reduction from the center to the center of the shaft and narrowed down to a small diameter (right side in the figure).

  At this time, the peripheral wall on the front end side of the cylindrical portion 1c is pressed against the outer surface of the small diameter portion 11e of the core metal 11a, and is regulated so as not to be narrowed down to a smaller diameter than the small diameter portion 11e. And since the front end side peripheral wall inner surface of the cylindrical part 1c is pressed against the male type | mold part 11f of the small diameter part 11e, the female type | mold part 1d of a spline is formed in a longitudinal direction along the front end side peripheral wall inner surface of the cylindrical part 1c. (See the cross-sectional view on the left side of FIG. 12).

  As a result, the shaft portion A2 of the yoke shaft A1 is integrally formed on one end side of the tube material 1, and the lower tube portion A3 of the yoke shaft A1 is integrally formed on the center portion of the tube material 1. . In addition, a space between the lower tube portion A3 and a yoke portion A4, which will be described later, is formed into a conical shape having a gradually increasing diameter from the lower tube portion A3 toward the yoke portion A4.

After the drawing process is completed, the die 11b is extracted from the outer peripheral side at one end of the tube material 1 and the cored bar 11a is pulled out from the opening at the other end side of the tube material 1. It is possible to proceed to the next second molding step.
In addition, you may process the female type | mold part 1d of a spline along the one end side surrounding wall inner surface of the pipe raw material 1 using a swaging processing method.

Subsequently, after the drawing of the tube material 1 is completed in the second drawing step, the forming is performed in the next second forming step.
In the second forming step, the tube material 1 drawn in the second drawing step is formed by holding the tube material 1 so that the other end side is downward and the one end side is upward. explain.

As shown in FIGS. 12A and 12B, the second molding step includes a second molding apparatus 12 including a rectangular mold 12a, a wide mold 12b, and a narrow mold 12c. ing.
The second molding device 12 inserts a rectangular mold 12a into the yoke molding portion 1b of the tube material 1 molded in the first molding step, and then forms a pair of wide surfaces on the front and rear wide surfaces of the yoke molding portion 1b. The metal mold 12b is pressed, a pair of narrow metal molds 12c are pressed against the narrow left and right surfaces of the yoke forming part 1b, and the yoke forming part 1b is pressed in a direction perpendicular to the longitudinal direction.

As a result, the yoke forming portion 1b is plastically deformed in a direction perpendicular to the longitudinal direction of the tube material 1 and formed into a rectangular cross section when viewed from above in the figure (see b in FIG. 12).
That is, with respect to the peripheral wall of the yoke forming portion 1b, the width of the wide side peripheral wall facing the front and rear is thinner than the center of the axis of the tube material 1, and the thickness of the narrow side peripheral wall facing the left and right is smaller than that of the front and rear peripheral walls. Plastically deforms into a rectangular cross-sectional shape that becomes thicker.

  In addition, the yoke forming portion 1b is formed into a rectangular cross section that has a wide peripheral wall width that faces the front and rear sides and a left and right peripheral wall width that is narrower than the front and rear peripheral wall widths. In addition, the left and right narrow surfaces of the yoke forming portion 1b are formed flat.

After the work for forming the yoke forming portion 1b of the tube material 1 into a rectangular shape is completed, the rectangular mold 12a is extracted from the other end side opening of the tube material 1, and the wide mold 12b and the narrow mold 12c are removed. If the tube material 1 is separated from the outer surface on the other end side, the tube material 1 that has been molded can be transferred to the next trimming process.
Subsequently, after the forming of the tube material 1 is completed in the second forming step, the aligning process is performed in the next aligning step.

As shown in FIG. 13, the trimming process includes a trimming device 13 having a trimming blade 13a.
The trimming device 13 cuts off the end of the yoke forming portion 1b and the cylindrical portion 1c of the tube material 1 molded in the second molding step with a trimming blade 13a, The other end side is trimmed to a flat end surface in parallel with a surface orthogonal to the longitudinal direction (or axial direction) of the tube material 1.

  That is, the tube material 1 whose both ends are supported by a support means (not shown) is rotated at high speed in one direction (the direction indicated by the arrow in the figure) around the axis of the tube material 1 (right side in the figure). At the same time, while moving the upper and lower trimming blades 13a close to the one end side outer periphery and the other end side outer periphery of the tube material 1 in the axial center direction along the one end side outer periphery and the other end side outer periphery, One end side and the other end side of the tube material 1 are trimmed to a flat end surface orthogonal to the longitudinal direction of the tube material 1 (left side in the figure).

  As a result, in the first drawing step and the second forming step, the protruding portions and burrs formed on one end side and the other end side of the tube material 1 are removed, and one end side and the other of the tube material 1 are removed. The end side can be trimmed to a predetermined dimension.

After the cutting process is completed, the cutting blade 13a is separated from the outer peripheral edge on one end side and the outer peripheral edge on the other end side of the tube material 1, and the support of the tube material 1 by the support means (not shown) is released, thereby completing the alignment. The pipe material 1 thus made can be transferred to the next notch process.
Subsequently, after the pipe material 1 is completely aligned in the trimming process, processing is performed in the next notch process.

As shown in FIGS. 14 (c) and 14 (d) and FIGS. 15 (e), 15 (f) and 15 (g), the notch process includes a notch die 14a and a receiving die 14b. A notch device 14 is provided.
The notch device 14 inserts a notch die 14a into the yoke forming portion 1b of the tube material 1 formed in the first forming step, and the corner corner outer surface of one wide side peripheral wall of the yoke forming portion 1b. After pressing the pair of receiving molds 14b, a U-shaped notch 1e as viewed from the side is cut out on one wide side peripheral wall and the other wide side peripheral wall of the yoke forming portion 1b.

First, when the notch 1e is cut into one wide side peripheral wall of the yoke forming portion 1b of the tube material 1, the yoke forming of the tube material 1 is performed as shown in FIGS. 14 (c) and 14 (d). A U-shaped notch die 14a formed narrower than the space between the opposing surfaces of the narrow side peripheral wall facing the left and right of the yoke forming portion 1b is inserted into the portion 1b.
At this time, the notch mold 14a is inserted so as to face the inner surface of the one wide side peripheral wall so that a part of a notch portion 1e described later is notched.

After pressing and supporting the pair of receiving molds 14b on the corner corner outer surface of one wide side peripheral wall, the notch mold 14a is moved in a direction in which one wide side peripheral wall is sheared in the thickness direction, A part of the wide side peripheral wall (number 1 shown in FIG. 15E) is cut in the thickness direction.
Thereby, a part of a notch portion 1e described later is notched and formed on one wide side peripheral wall of the yoke forming portion 1b.

Further, after inserting the notch mold 14a by a length that allows the remaining part of the notch 1e to be sheared, the remaining part of the notch 1e (the number 2 shown in FIG. 15 (e)) is the same as described above. The wide peripheral wall corresponding to the portion is cut out in the thickness direction.
As a result, a U-shaped cutout portion 1e made up of the number 1 portion and the number 2 portion shown in FIG. 15 (e) is cut into one wide side peripheral wall of the yoke forming portion 1b. .

  Next, when the notch 1e is cut into the other wide side peripheral wall of the yoke forming portion 1b, the notch mold 14a is placed on the other wide side peripheral wall with respect to the inside of the yoke forming portion 1b having a rectangular shape. Opposite the inner surface, all of a notch portion 1e described later (number 3 shown in FIG. 15 (f)) is inserted by a length that is notched.

  After pressing and supporting the pair of receiving molds 14b against the corner corner outer surface of the other wide side peripheral wall, the notch mold 14a is moved in a direction in which the other wide side peripheral wall is sheared in the thickness direction, A U-shaped notch 1e (number 3 shown in FIG. 15 (f)) is cut at a time on the other wide side peripheral wall of the yoke forming portion 1b.

  After the U-shaped notch 1e is cut into the opposing wide side wall of the yoke forming portion 1b (see FIG. 15 (g)), the notched die 14a is replaced with the tube material 1 If the pair of receiving dies 14b are separated from the outer surface of the corners of the tube material 1, the notched tube material 1 is transferred to the next drilling step. can do.

  Subsequently, after the notch of the tube material 1 is completed in the notch process, processing is performed in the next drilling process. Further, after the notch 1e is notched, the front end side of the opposing narrow side peripheral wall of the yoke forming portion 1b is processed into a smooth R shape.

  Note that a U-shaped cutout portion 1e may be cut out at a stroke on one wide side peripheral wall of the yoke forming portion 1b. Further, in the notch process, the notch 1e is divided in the longitudinal direction with respect to the wide side peripheral wall of the yoke forming portion 1b and cut out, but is divided in the width direction with respect to the wide side peripheral wall and cut out. May be.

As shown in FIG. 16, the drilling step includes a drilling device 16 having a drill 16a.
The perforating device 16 is provided in the longitudinal direction of the tube material 1 while rotating the drill 16a at high speed on one narrow side peripheral wall and the other narrow side peripheral wall of the yoke forming portion 1b formed in the first forming step. The hole 1f is pierced in a direction orthogonal to the horizontal direction in the figure and penetrated in the thickness direction with respect to one narrow side peripheral wall and the other narrow side peripheral wall in the thickness direction.

  First, a round hole is formed by penetrating a drill 16a of a drilling device 16 in the thickness direction while rotating at a high speed on one narrow side peripheral wall of a yoke forming portion 1b of a tube material 1 supported by a support means (not shown). The part 1f is drilled through the one narrow side peripheral wall in the thickness direction (left side in the figure).

Thereafter, the drill 16a of the drilling device 16 is penetrated in the thickness direction while rotating at a high speed through the other narrow side peripheral wall of the yoke forming portion 1b, and the round hole 1f is formed in the other narrow side peripheral wall. On the other hand, a hole is formed by penetrating in the thickness direction (see the horizontal sectional view of the yoke forming portion 1b shown on the right side of FIG. 16 and the upper left side of FIG. 16).
Thereby, the yoke portion A4 having a U-shape of the yoke shaft A1 is integrally formed on the other end side (upper end side in the drawing) of the tube material 1.

  If the drill 16a is extracted from the hole 1f of the yoke forming part 1b after the work of drilling the circular hole 1f in the opposing narrow side peripheral wall of the yoke forming part 1b is completed, FIG. 1 and FIG. The manufacture of the yoke shaft A1 shown on the right side of FIG.

  As described above, the yoke shaft A1 in which the shaft portion A2, the lower tube portion A3, and the yoke portion A4 are integrally formed by processing the single metal pipe material 1 formed in the hollow shape. Thus, the strength of the yoke shaft A1 is not partially weakened, and a high strength can be secured as the yoke shaft A1.

  Further, since the labor and work of machining the shaft part A2, the lower tube part A3, and the yoke part A4 separately or welding each part integrally can be omitted, the work of manufacturing the yoke shaft A1 is simple and easy. It can be done. Further, not only the time required for production is greatly shortened, but also the number of processes and parts at the time of production is reduced, so that the production cost can be reduced.

In the correspondence between the configuration of the present invention and the embodiment,
The drawing process of the present invention corresponds to the first and second drawing processes of the embodiment,
Similarly,
The molding process corresponds to the first and second molding processes,
The present invention is not limited to the configuration of the above-described embodiment, but can be applied based on the technical idea shown in the claims, and many embodiments can be obtained.

A1 ... Yoke shaft A2 ... Shaft portion A3 ... Lower tube portion A4 ... Yoke portion 1 ... Pipe material 1a ... Hard portion 1b ... Yoke molding portion 1c ... Tubular portion 1d ... Female die portion 1e ... Notch portion 1f ... Hole portion 2 DESCRIPTION OF SYMBOLS ... Press type press apparatus 3 ... Arrow threading apparatus 4 ... Falling apparatus 5 ... 1st shaping | molding apparatus 6 ... Molding part cutting apparatus 7 ... Unmolded part cutting apparatus 8 ... 1st drawing apparatus 9 ... Annealing apparatus 10 ... Bonde apparatus DESCRIPTION OF SYMBOLS 11 ... 2nd aperture apparatus 12 ... 2nd shaping | molding apparatus 13 ... Trimming apparatus 14 ... Notch apparatus 16 ... Drilling apparatus

Claims (3)

A method for producing a yoke shaft comprising a shaft portion provided on one end side of a metal tube material and a yoke portion provided on the other end side of the tube material,
A range extending from one end side to the central portion of the tube material is radially extended, and the inner peripheral wall surface of the range is larger in diameter than the inner diameter of the inner peripheral wall surface on the other end side of the tube material. An arrow-passing process to process the thickness to be thinner than the peripheral wall on the other end side;
A cutting step of cutting the outer peripheral surface of the tube material by a desired thickness;
On one end side of the tube material, one end side of the tube material is drawn to a smaller diameter than the other end side to form a shaft portion, and a spline is processed in the longitudinal direction along the inner surface of the one end side peripheral wall of the tube material. Drawing process;
On the other end side of the tube material, a molding step in which the other end side of the tube material is plastically deformed in a direction perpendicular to the longitudinal direction of the tube material to form a rectangular yoke forming part,
A U-shaped notch mold formed to be narrower than the space between the opposing surfaces of the opposing narrow side peripheral walls of the yoke molded portion is a second U-shaped cutout portion with respect to the inside of the yoke molded portion. A pair of receiving molds are inserted to the insertion position where one portion is sheared, and the corner corner outer surface of one wide side peripheral wall of the yoke forming portion is supported on the corner corner outer surface of the one wide side peripheral wall. After pressing the notch mold at an allowable interval,
The notch mold is moved from the inside to the outside in a direction in which the one wide side peripheral wall supported by the pair of receiving molds is sheared in the thickness direction, and the first portion of the one wide side peripheral wall Is cut in the thickness direction,
After the notch mold is inserted to the insertion position where the second part behind the first part in the notch is sheared, the one wide side peripheral wall is sheared in the thickness direction. Move from the inside to the outside, cut the second portion of the one wide side peripheral wall in the thickness direction, and form the U-shaped notch on the one wide side peripheral wall,
The U-shaped notch mold is inserted to the insertion position where the entire U-shaped notch is sheared with respect to the inside of the yoke molded part, and the other wide side peripheral wall of the yoke molded part After pressing a pair of receiving molds that support the outer surface of the corner of the other wide side wall on the outer surface of the corner of the other side at an interval that allows passage of the notch mold,
The notch mold is moved from the inside to the outside in a direction in which the other wide side peripheral wall supported by the pair of receiving molds is sheared in the thickness direction, and the notch portion of the other wide side peripheral wall is moved. A notch process in which a portion corresponding to the whole is notched in the thickness direction, and the U-shaped notch is formed on the other wide side peripheral wall;
A method of manufacturing a yoke shaft, comprising: a hole forming step of forming a hole formed through the narrow side peripheral wall of the yoke molded part in the thickness direction in the opposing narrow side peripheral wall of the yoke molded part. An annealing process for performing an annealing process for removing distortion generated in the pipe material between the cutting process and the drawing process, and a layer for uniformly forming a phosphoric acid compound layer on the entire surface of the pipe material The yoke shaft manufacturing method according to claim 1, further comprising a bond process for performing a bond process. Before the cutting step, a step of plastically deforming the other end side of the tube material in a direction perpendicular to the longitudinal direction of the tube material and forming an elliptical yoke forming part on the other end side of the tube material. The yoke shaft manufacturing method according to claim 1 provided.

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