JP2008114256A - Plastic working method of shaft spline - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the plastic working method of a shaft spline capable of suppressing production of burrs of a part subjected to plastic working of the spline of a shaft work, and preventing any raise-down of the large diameter at the tip end of the spline. <P>SOLUTION: In the plastic working method of the shaft spline for performing the plastic working of a spline on a shaft workpiece 24, the volume of the spline 30 to be formed is equal to the volume of a part to be plastically worked in the shaft workpiece 24, the diameter of a portion to firstly form the spline 30 is made maximum, and the spline extends from the firstly formed portion to a portion not to be plastically worked in a tapered shape. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a shaft spline plastic working method for plastic working a spline on a shaft work.

  For example, there is one that plastically processes a workpiece by frequency modulation (Patent Document 1), and this plastic processing can obtain a product as it is from a raw material, eliminating the need for removal of excess portions, reducing manufacturing costs, In addition, it is possible to eliminate the use of chips. Such plastic working is practically difficult to completely eliminate the removal of the excess portion, but can be reduced to a considerable extent.

As shown in FIG. 8, for example, when a spline is formed on the shaft work of an outboard motor by this plastic working, the shaft work 100 has a blank shape, and the spline is formed in consideration of the large diameter drop at the tip of the spline. The portion 101 to be plastically processed needs to have a tip portion 101a in a trumpet shape.
Japanese Patent No. 3572544

  Thus, forming the tip 101a of the portion 101 for plastic processing of the spline into a trumpet shape is not limited to plastic processing of the shaft workpiece 100 by frequency modulation, but can also be implemented by other plastic processing, for example, spline rolling. Has been.

  However, when the shaft workpiece 100 is plastically processed in a blank shape, burrs 120a are generated at the tooth ridges 120 between the splines 110 as shown in FIG.

  The present invention has been made in view of the above points, and is a shaft spline plastic working capable of suppressing the occurrence of burrs at the portion of the spline of the shaft work that is plastic-worked and preventing the large-diameter drop of the tip of the spline. It aims to provide a method.

  In order to solve the above problems and achieve the object, the present invention is configured as follows.

The invention according to claim 1 is a shaft spline plastic working method for plastic working a spline on a shaft work,
The shaft work is
Make the volume of the spline to be molded equal to the volume of the plastic working part,
And, with the part where the spline is first molded as the maximum diameter,
Extending from the first molded part to the part not plastically processed in a conical shape,
A shaft spline plastic working method characterized by the above.

In the invention according to claim 2, a relative movement is generated between the shaft work and the mold by the feeding device, and a spline is plastically processed by frequency modulation on the shaft work.
The shaft spline plastic working method according to claim 1.

  With the above configuration, the present invention has the following effects.

  According to the first aspect of the present invention, the shaft work is formed such that the volume of the spline to be molded is equal to the volume of the plastic processing portion, and the portion where the spline is formed first is the maximum diameter, and the cone is formed from the portion where the spline is formed first. By extending to a portion that is not plastically processed, there is no inflection point, it is possible to suppress the occurrence of burrs, and prevent the large diameter drop at the tip of the spline. The removal process of the part is not necessary, and the manufacturing cost can be reduced.

  In the invention according to claim 2, the spline is plastically processed by frequency modulation on the shaft work, and the mold is pushed into the shape material while being vibrated at a certain frequency at the front and back, that is, while being frequency-modulated, and molded. As a result, the feed force is reduced by half compared to continuous plastic working, the operation energy is saved, and molding is possible with a small apparatus. In addition, the processing oil is always supplied to the forming point during backward movement due to the longitudinal vibration, preventing seizure between the mold and the shape material, and the small feed force can also prevent the shape material from being bent or deformed.

  Hereinafter, embodiments of the shaft spline plastic working method of the present invention will be described. However, the embodiments of the present invention show the most preferable modes of the present invention, and the present invention is not limited thereto.

  FIG. 1 is a schematic view of a shaft spline plastic working apparatus, FIG. 2 is a sectional view of a mold for shaft spline plastic working, FIG. 3 is a side view before machining the shaft workpiece, and FIG. 4 is a side view after machining the shaft workpiece. FIG. 5 is an enlarged view of a tooth ridge between splines.

  As shown in FIG. 1, the shaft spline plastic working apparatus 1 of this embodiment is an apparatus for plastic working a spline on a shaft work 24, and the apparatus main body 2 is provided with a column 3 and a chuck 4. Yes. Tie bars 5 and 6 are provided between the support column 3 and the chuck 4. A slider 15 is movably provided on the tie bars 5 and 6. A mold holder 7 is attached to the slider 15. 7 has a built-in die 8.

  Further, the support 3 is provided with a first feeding device 9. A pressure cylinder 10 is used for the first feeding device 9, and the mold 8 is moved through a mold holder 7 provided on the slider 15. The first feeding device 9 includes a frequency modulation device 11, and the frequency modulation device 11 performs frequency modulation necessary for plastic working.

  The apparatus main body 2 is provided with a column 20, and a second feeding device 21 is attached to the column 20. A workpiece insertion cylinder 22 is used for the second feeder 21, and a shaft workpiece 24 is inserted into a workpiece grip 23 of the workpiece insertion cylinder 22. The shaft work 24 is moved in the direction of the mold 8 by the work insertion cylinder 22 to generate a relative motion between the shaft work 24 and the mold 8, and a spline is plastically processed in the shaft work 24.

  Next, the operation of this shaft spline plastic working will be described. First, the shaft work 24 is inserted and attached to the work grip 23, and the shaft work 24 is moved into the chuck 4 via the work grip 23 by the operation of the work insertion cylinder 22 and is held by the chuck 4. Then, the mold holder 7 is advanced by the processing cylinder 10 while being frequency-modulated by the frequency modulator 11. At this time, the mold 8 in the mold holder 7 is subjected to plastic deformation to the shaft work 24 to form a spline.

  After plastic processing of the shaft spline, the mold holder 7 is moved backward by the processing cylinder 10. The holding of the chuck 4 is released, the shaft work 24 is moved backward by the operation of the work insertion cylinder 22, and the shaft work 24 formed with the spline is removed from the work grip 23.

  Next, as shown in FIG. 2, the mold 8 held by the mold holder 7 is composed of a thin steel strip, and the mold holder 7 has a mold 12 via a sleeve 12. A mold 8 is provided. Further, a machining oil passage 13 is formed in the mold holder 7.

  In the plastic processing of the shaft spline, the shaft work 24 made of a shaped material is strongly clamped, and the mold 8 on which the spline shape is reversely transferred is strongly pushed into the shaft work 24 made of the shaped material, thereby forming the spline. The size and shape of the spline depends on the shape of the mold. Since the mold 8 is held in a state of being press-fitted into the mold holder 7, it is necessary to satisfy the required shape in the press-fitted state. Further, the mold 8 is made of carbide, and the spline tooth profile once manufactured cannot be changed in practice. In order to improve these problems, the mold 8 is held by the sleeve 12 on the mold holder 7 through a thin steel strip of metal spring inside, and the holding position of the mold 8 in the front-rear direction is adjusted in units of 0.5 mm, for example. Adopts a possible structure. With this structure, the overpin diameter of the shaft work 24 can be finely adjusted within a range of a maximum of 0.1 mm.

  As shown in FIG. 3, the shaft work 24 has a spline effective length L2 for plastic processing of the spline. The spline effective length L2 is a portion that transmits power by engaging with a connecting member. The diameter D2 of the distal end portion 24c is larger than the diameter d2 of the base portion 24b of the spline effective length L2, and the base portion 24b extends to the distal end portion 24c. It is formed in a conical shape having a straight inclined surface 24d having a predetermined angle θ2.

A portion 24a for plastic working the spline of this embodiment is:
Diameter D2 of tip 24c = 21.02.
Diameter d2 = 20.145 of the base 24b
Effective spline length L2 = 9.688> Effective spline length 7.8
The predetermined angle θ2 = 2.747 degrees is set.

  According to the setting of this embodiment, the shaft work 24 has the tip end portion 24c, which is the portion where the spline is first formed, having the same diameter as the volume of the spline to be formed and the volume of the plastic processing portion. It extends from the part 24c to a base part 24b which is a part that is not plastically processed in a conical shape.

  A shaft spline plastic working apparatus shown in FIG. 1 is used for the shaft work 24, and a spline 30 as shown in FIGS. 4 and 5 is plastic processed by frequency modulation.

  The plastic processing of the shaft spline 30 is performed by strongly pressing the die 8, which is anti-transferred from the spline shape, into the base material to form the spline 30. In the plastic working by frequency modulation, the metal mold 8 is pushed into the shaft work 24 of the base material while being oscillated at the front and rear frequencies (optimized and adjusted by the material and specifications), that is, while being subjected to the frequency modulation motion. As a result, the feed force is reduced by half and the operating energy is reduced as shown in FIG. 6 in comparison with the continuous plastic working, and molding can be performed with a small apparatus. In addition, the processing oil is always supplied from the processing oil passage 13 to the forming point by the back-and-forth vibration, and the seizure between the mold 8 and the shaft work 24 of the base material is prevented, and a small feed force can be obtained by bending the base material. Deformation can also be prevented.

  Plastic processing by frequency modulation can be achieved in an overwhelmingly short time with a removal processing ratio by a hob of 1/10 or less. Compared with removal processing with a hob, the pitch error and tooth profile error are improved by 1 to 3 grades according to the JIS accuracy standard.

  As the plastic processing oil, a chlorine-based extreme pressure agent is used particularly in the application of a hardly plastic material such as stainless steel. In this embodiment, a chlorine-free plastic processing oil suitable for spline plastic processing is used.

  As shown in FIG. 7, by using chlorine-free plastic working oil, the pressing force could be kept constant until the plastic working by frequency modulation was completed, and a minimum returning force could be obtained.

  As shown in FIG. 3, the shaft work 24 is formed into a raw material by performing a forging process after cold forging a low carbon alloy steel. The shape of the base material is such that the volume of the spline 30 to be molded is equal to the volume of the part to be plastically processed by frequency modulation, and the tip 24c, which is the part where the spline 30 is first molded, is the maximum diameter. It extends from 24c to a base 24b which is a portion not subjected to plastic working by frequency modulation in a conical shape. If there is no bending point in the shape of the range subjected to plastic processing by frequency modulation, it is possible to eliminate the occurrence of burrs in the tooth ridge 31 as shown in FIGS.

  In this way, the shaft work 24 has no inflection point, can suppress the occurrence of burrs, and can prevent the large diameter drop at the tip of the spline. Removal processing is unnecessary, and the manufacturing cost can be reduced.

  Also, the spline 30 is plastically processed by frequency modulation on the shaft work 24, and the mold 8 is vibrated at a certain frequency at the front and back, that is, while being frequency-modulated, and is molded into the base material to form a feed force. Compared to continuous plastic working, it reduces the operating energy by half and enables molding with a small device. In addition, the processing oil is always supplied to the forming point during backward movement due to the longitudinal vibration, preventing seizure between the mold 8 and the shape material, and the small feed force can also prevent the shape material from being bent or deformed.

  In this embodiment, the case where the spline 30 is plastically processed by frequency modulation on the shaft work 24 has been described. However, the present invention is not limited to this, and can also be applied to the case of plastic processing without frequency modulation. The shaft work 24 is used for power transmission of the outboard motor, but is not limited to this, and can also be used for power transmission of the vehicle.

  In outboard motors, two shafts are used to transmit power from the engine that is the prime mover to the propeller that is the propulsion unit. A drive shaft directed downward from the rear end of the crankshaft of the engine arranged vertically, and a propeller shaft that intersects the drive shaft and a gear set at a right angle. Each of these shafts has splines at both ends.

  The present invention can be applied to a shaft spline plastic working method for plastic processing of a spline on a shaft work, suppresses the generation of burrs in a portion of the shaft work where the spline is plastic processed, and prevents a large-diameter drop at the tip of the spline. Is possible.

It is the schematic of a shaft spline plastic working apparatus. It is sectional drawing of the metal mold | die of shaft spline plastic working. It is a side view before the process of a shaft workpiece. It is a top view after processing of a shaft work. It is an enlarged view of the tooth ridge part between splines. It is a figure which shows a plastic working feed force comparison. It is a figure which shows feed force evaluation. It is a side view before the process of the conventional shaft workpiece. It is a top view after the process of the conventional shaft workpiece.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shaft spline plastic processing apparatus 2 Apparatus main body 3 Support | pillar 4 Chuck 5,6 Tie bar 7 Mold holder 8 Mold 9 1st feeder 10 Pressurizing cylinder 11 Frequency modulator 20 Strut 21 2nd feeder 22 Workpiece insertion cylinder 23 Work grip 24 Shaft work 24a Plastic processing part of spline 24b Base 24c Tip 24d Inclined surface

Claims (2)

It is a shaft spline plastic working method for plastic working a spline on a shaft work,
The shaft work is
Make the volume of the spline to be molded equal to the volume of the part to be plastically processed,
And, with the part where the spline is first molded as the maximum diameter,
Extending from the first molded part to the part not plastically processed in a conical shape,
A shaft spline plastic working method characterized by the above. A relative movement is generated between the shaft work and the mold by the feeding device, and a spline is plastically processed by frequency modulation on the shaft work.
The shaft spline plastic working method according to claim 1.