JPS63120958A - Speed change gear and manufacture thereof - Google Patents

Abstract

PURPOSE:To shorten the overall length of a gear wheel, by forming the boss part integrally with the gear wheel, and forming spline grooves on the outer circumferential surface of the boss part in a reversed taper shape so as to reach the root of the boss part. CONSTITUTION:On the outer circumference of a gear wheel 1, teeth 2 for speed change are formed, and on the one side of the gear wheel 1 a boss part 3 which is made to have a diameter slightly smaller than the outside diameter of the gear wheel is formed integrally with the body 1 of the gear wheel. On the outer circumferential surface of the boss part 3, reversed-taper-shaped spline grooves 4 are formed as a slip-out stopper for a transmission. The spline grooves 4 reach the root of the boss part 3 or the part where the gear wheel is connected. Thus, the effective length of splines can be lengthened, and the overall length of the gear wheel can be shortened.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is used in a synchromesh type transmission, and has reverse tapered spline teeth formed on the outer periphery of a boss portion of a gear up to the root of the boss portion. This relates to gears for speed change.

[Prior art and its problems]

The transmission gear with clutch spline teeth, which is conventionally used in synchronized mesh type transmissions, has a method in which a slot for machining the spline is provided at the root of the spline from a gear blank, and the gear is machined and molded integrally with the transmission gear. , the gearshift tooth part and the clutch spline tooth part with a reverse tapered tooth profile are manufactured separately by machining or cold forging, and the clutch spline tooth part is fitted onto the outer periphery of the gearshift tooth part, which is finished with high precision. There is a method of integrating the outer surface of one part of this joint by electron beam welding. The former has the disadvantage that the effective length of the spline is shortened because a clearance is provided at the base of the spline. or,
The latter has the disadvantage that the metal flow between the spline tooth portion and the speed change tooth portion is broken, weakening the strength, and requiring machining and welding assembly processing, resulting in high cost.

For example, there is a method of improving this two-part type and forming the speed change tooth part and the spline tooth part integrally in a forging process.
No. 11543 and Japanese Unexamined Patent Publication No. 52-61162. However, in the former case, the spline teeth are straight and reverse tapered spline teeth cannot be formed. In the latter case, it is shown that the spline tooth profile is inversely tapered to the boss portion and integrally molded by cold-open molding, but the root portion of the spline tooth is machined. (See Figure 3 of the publication) Therefore, in the latter case as well, the effective length of the spline teeth is short, and cutting is required.

The present invention aims to form spline teeth using only a forging process and to increase the effective length of the spline teeth.

[Means for solving the problem] A gear with gear shifting teeth formed on its outer periphery is integrated with a boss portion having a diameter smaller than the gear diameter, and reverse taper spline teeth are formed on the outer peripheral surface of this boss portion, and the reverse taper spline teeth are Forged to the base of the boss.

This inverted taper spline tooth shaping process involves forging spline teeth parallel to the gear axis, and then using a number of dies corresponding to the number of teeth in the gear material, which are slidable toward the gear axis, and then fitted into the lower die. A cam that is inserted and supported and pushed down by the lowering of the upper die facing the lower die is supported so as to be able to slide vertically in a case provided on the lower die mounting base, and is abutted at the rear end of each die. This is done using a device in which the die contact surface of each cam is an inclined surface such that the die moves in the direction of the gear axis when the cam is pressed down.

〔Example〕

Next, the present invention will be explained based on embodiments shown in the drawings.

FIG. 1 is a front view showing a gear for shifting according to the present invention, 1 is a gear, 2 is a gear for gear shifting formed on the outer periphery of this gear, such as a helical tooth, and 3 is a gear on one side of gear 1. This boss part 3 has a diameter slightly smaller than the outer diameter. This boss part 3 is integrally molded with the main body 1 of the gear, and the outer peripheral surface of this boss part 3 has a reverse taper shape to prevent the transmission from being removed. Spline teeth 4 are formed. The spline teeth 4 are made to reach the root of the boss portion 3, that is, the connection portion with the gear portion.

Next, a method and apparatus for manufacturing a transmission gear according to the present invention will be explained.

Steel materials that can be used as gears, such as SC#l, SC old LS
NCw4, SNCMm, SCRgl1, etc. are generally cut to suit the size, shape, diameter, etc. of the gear to be manufactured.

The raw material W cut to the required length is then heated at a heating temperature determined according to the type, size, and weight of the raw material so that the temperature is suitable for hot forging, that is, plastic working.

This heated material W is upset-formed like HW by hot forging, that is, plastic working, in an upsetting step to match the shape of the gear to be formed. In this case, the upsetting outer diameter is matched to the outer diameter of the gear to be manufactured so as to be suitable for the next step of plastic working.

Next, the upholstered material HW is placed in a forging die and subjected to one process or multiple processes such as a roughing process and a finishing process to integrally form a transmission tooth profile and a spline tooth profile like a FW. The spline teeth 4 formed by this forging die are made slightly smaller than the predetermined tooth profile, and then the tooth profile is made with a predetermined accuracy through a cold coining process in which the excess inside the shaft hole side is plastically processed to the outside of the material. Make it last. In the next step, a shaft hole 5 is bored in the material FW on which the outer shape of the gear has been formed. In this case as well, the diameter of the shaft hole 5 is made smaller than the set shaft hole diameter, and the shaft hole portion is provided with an extra thickness. During this process, other necessary post-processing steps such as standardization and shot blasting may be performed as necessary.

Material FW with spline tooth profile formed in advance in this way
is then sent to cold coining step 5. This cold coining pushes the extra wall inside the shaft hole side to the outside of the material, allowing the spline to have a predetermined accuracy. The material in which splines parallel to the gear axis have been formed in this manner is sent to a reverse slope forming step 6.

Reverse gradient molding is performed using a manufacturing apparatus as shown in FIGS. 4 and subsequent figures.

Next, this manufacturing apparatus will be explained.

The upper die 11 is attached to the upper die mount 12 in a spring-pressed state, and the lower die 13 facing the upper die 11 is fixed to the lower die mount 14, and a punch 15 is provided to protrude from the lower die mount 14. is passed through the inside of the lower die 13, a cylindrical knockout cylinder 16 is arranged around the outer periphery of the bunch 15, and an annular case 17 is fixed to the lower die mounting base. When shaping the tooth profile in the reverse slope forming process, a large number of cam fitting holes 17H are drilled at a fixed pitch in accordance with the tooth angle and number of teeth of this gear, and the outer periphery of the cam fitting holes 17H is formed in this case 17. The inner side surface is a cam pressing surface 17F, and this cam pressing surface is a plane that is vertical and perpendicular to the longitudinal axis of the die, and a cam 21 is fitted into each hole 17H. An annular flange 18 is also mounted on the lower mold mount 14 and supported by a spring 24 attached to the lower mold mount.
The flange supports the bottom of the cam 21 that is fitted into the cam insertion hole, and the cam 21 is bolted to the flange 18.

The cam 21 is finished in a flat shape with high precision so that its back surface contacts the cam pressing surface 17F, and a bottle 22 is protruded and fixed inside the lower part with the upper end inclined inward. A die pressing surface 21T having an inclination angle equal to the inclination angle of 22 is provided on the inner surface of the cam, and
Formed opposite to 2.

As shown in detail in FIGS. 6 and 7, die fitting holes 13H are formed in the upper part of the lower mold 13 at predetermined angles along a straight line toward the center of the lower mold that matches the angle between the teeth of the gear. These die insertion holes 13H have a circular cross section and are cut flat at the top and are open. 23 are respectively inserted and arranged radially, and the case 1
7 holds down the flat part of the die to prevent the die 23 from rotating.

At the tip of this die 23, each tooth of the gear can be shaped into a predetermined reverse taper spline tooth.

Further, after the material FW mounted in the lower mold 13 is lowered by the upper mold 11 and the reverse taper spline teeth are shaped by the die 23, when this material FW is taken out from the lower mold, the knockout bin 1
15.19 and the knockout cylinder 20 so that it can be easily taken out. Knockout bottle 19 has flange 18
quickly push up the knockout bin 19.1 so that the knockout bin 16 pushes up the knockout cylinder 20.
Determine the length of 6. As a result, after the re-die is removed outward from the teeth of the material FW, the material FW is made to protrude from the inside of the lower die.

The raw material FW, which has been formed with a spline tooth profile in advance in a forging process, is set in a lower die using the manufacturing apparatus configured as described above. Next, when the upper mold is lowered, the material FW is held between the upper and lower molds by the upper mold under the pressure of the spring, and the upper surface of the cam 21 is also gripped a little later than when the material is clamped by the lowering of the upper mold. Pressed.

At this time, since the lower mold is fixed, the cam 21 and flange 18 are pushed down by the lowering of the upper mold.
As a result, the rear end of the die 23 is pushed by the tapered die pressing surface 21T of the cam, each die slides in the direction toward the center of the lower die, and the spline tooth profile of the material is adjusted to a predetermined shape at the die tip 23D. The teeth are shaped into reverse taper spline teeth. Thereafter, the upper die is raised and the knockout bin 19 is pushed up, thereby also returning the flange 18. When the flange returns or rises, the cam 21 is also raised, and the bin 2 that is inclined and protrudes from the cam 21 is also raised.
2, since the rear end of the die is connected through the die, when the bin 22 is raised, the die 23 is fitted into the lower die 13 and can only slide radially;
It is something that retreats and returns.

After the tip of the die is separated from the tooth profile of the material FW, the material F is removed using the knockout bin 16 and the knockout tube 2°.
W is pushed up from inside the lower mold and taken out from the lower mold.

〔Effect of the invention〕

According to the present invention, a gear having gear shifting teeth formed on its outer periphery is integrated with a boss portion having a smaller diameter than the gear diameter, and reverse taper spline teeth are formed on the outer peripheral surface of the boss portion. Since the boss part is forged to the root and is formed by compression shaping with a die that matches the number of teeth, reverse taper spline teeth can be manufactured only by the forging process, and since these spline teeth have metal flow. This has the advantage of increasing the strength and increasing the effective length of the spline teeth, allowing the overall length of the gear to be shorter than that of conventional products, making it possible to downsize the transmission.

[Brief explanation of the drawing]

FIG. 1 is a front view of the transmission gear of the present invention, FIG. 2 is a sectional view,
Fig. 3 is an explanatory diagram showing the manufacturing process, Fig. 4 is a sectional view of the manufacturing equipment that performs cold inverse gradient forming, Fig. 5 is a plan view, Fig. 6 is a plan view of the lower mold, and Fig. 7 is A front view showing a part of the lower die and FIG. 8 are explanatory views of the die. 1 is a gear, 2 is a helical tooth, 3 is a boss, 4 is a spline tooth, WHW is a material, 11 is an upper mold, 13 is a lower mold, 17 is a case, 18 is a flange, 21 is a cam, 22 is a bottle, 2
3 is the die Figure 2 Figure 1 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 (A) 3H (C) Procedural amendment (self-control patent application No. 131-266257, December 29, 1985) 2. Name of the invention Transmission gear and its manufacturing device 3. Relationship with the case of the person making the amendment Patent applicant address 1350 Noji-cho, Kusatsu City, Shiga Prefecture Name
Goto Forging Co., Ltd. Representative Kikuji Terada 4, Agent Akira Shima 1 Name of the invention Transmission gear and apparatus for manufacturing the same 2 Claims (1) Synchronous mesh type transmission gear having teeth on the outer periphery Then, a boss is integrally formed on this gear, and a spline groove is formed on the outer circumferential surface of this boss up to the root of the boss.
A gear for changing gears, characterized in that the gear is formed with a reverse taper and the effective length of the spline groove is made as long as possible. (2) A large number of dies corresponding to the number of teeth of the gear material formed by forging spline teeth parallel to the gear axis are made slidable toward the gear axis, and are inserted and supported by the lower die. A cam that is pushed down by the lowering of the upper mold facing the mold is supported so as to be able to slide vertically in a case provided on the lower mold mount, and the die abutment of each cam is abutted at the rear end of each die. A manufacturing device for a transmission gear, characterized in that the contact surface is an inclined surface such that the die moves in the direction of the gear axis when the cam is pressed down, and the spline groove is shaped into an inversely tapered shape. 3. Detailed Description of the Invention [Field of Industrial Application] The present invention is used in a synchromesh type transmission, and is used to form a reverse tapered spline groove formed on the outer periphery of a boss portion of a gear up to the root of the boss portion. It is installed between the gears for gear change. [Prior art and its problems] The clutch spline toothed transmission gear conventionally used in synchromesh type transmissions has a clearance provided at the root of the spline for machining the spline from the gear blank, and is connected to the transmission tooth part. The clutch spline tooth part, which has an inversely tapered tooth profile, is machined or cold-forged separately, and the clutch is attached to the outer periphery of the precision-finished gear tooth part. There is a method in which spline teeth are fitted and the outer surfaces of this joint are integrated by electron beam welding. The former has the disadvantage that the effective length of the spline is shortened because a clearance is provided at the base of the spline. In addition, the latter has the disadvantage that the metal flow between the spline tooth portion and the speed change tooth portion is broken, weakening the strength, and requiring machining and welding machining, resulting in high cost. For example, there is a method that improves this two-part type and integrally forms the speed change tooth part and the spline tooth part in a forging process.
No. 11543 and Japanese Unexamined Patent Publication No. 52-61162. However, in the former case, the spline groove is straight and a reversely tapered spline groove cannot be formed, and in the latter case, the spline groove shape is reversely tapered at the boss part and is cold formed. Although it is shown that it is integrally molded, the root portion of the spline groove is machined. (Refer to Figure 3 of the publication) Therefore, in the latter case as well, the effective length of the spline groove is short, and cutting is required. An object of the present invention is to form a spline groove using only a forging process and to increase the effective length of the spline groove. [Means for solving the problem] A gear having gear shifting teeth formed on its outer periphery is integrated with a boss portion having a diameter smaller than the gear diameter, and a spline groove is formed on the outer circumferential surface of this boss portion, and this inversely tapered spline groove is formed. is formed by forging all the way to the base of the boss. This inverted taper spline groove is formed by forging a spline groove parallel to the gear axis using a number of dies corresponding to the number of teeth of the gear material, which are slidable toward the gear axis and then fitted into the lower die. A cam that is inserted and supported and pushed down by the lowering of the upper die facing the lower die is supported so as to be able to slide vertically in a case provided on the lower die mounting base, and is abutted at the rear end of each die. This is done using a device in which the die contact surface of each cam is an inclined surface so that the die moves in the direction of the gear axis when the cam is pressed down. [Example] Next, the present invention will be described based on an example shown in the drawings. FIG. 1 is a front view showing a gear for changing gear of the present invention, 1 is a gear, 2 is a tooth for gear changing, such as a helical tooth, formed on the outer periphery of this gear, and 3 is a gear outside the gear at one part of this gear l. The second boss part 3 is formed integrally with the main body l of the gear, and the outer peripheral surface of this boss part 3 has a reverse taper shape to prevent the transmission from being removed. A spline groove 4 is formed. This spline i14 is made to reach the root of the boss portion 3, that is, the connection portion with the gear portion. Next, the manufacturing method of the gear for speed change according to the present invention and its H position will be explained. Steel materials that can be used as gears, such as SC steel, 80M steel, S
Generally, NC steel, SNCM steel, SCR steel, etc. are cut to a size suitable for the size, shape, diameter, etc. of the gear to be manufactured. The material W cut to the required length is then heated to a temperature suitable for hot forging, that is, plastic working, by adjusting the material type, size, f[
Heating is performed by determining the heating temperature according to ffi. This heated material W is upset-formed like HW by hot forging, that is, plastic working, in an upsetting step to match the shape of the gear to be formed. In this case, the upsetting outer diameter is matched to the outer diameter of the gear to be manufactured so as to be suitable for the next step of plastic working. Next is this hemmed material HWIti1! The transmission tooth profile and the groove shaped part that will become the spline tooth are integrally formed like a FW by putting it into a mold and going through one process or a plurality of processes such as a rough process and a finishing process. The protrusion between the spline grooves 4 and 4 formed by this forging die is made slightly smaller than the predetermined tooth profile,
Next, this is subjected to a cold coining process in which the excess material inside the shaft hole is plastically processed to the outside of the material so that the tooth profile has a predetermined accuracy. In the next step, the cable material F that formed this gear outer shape is
Drill shaft hole 5 in W. In this case as well, the diameter of the shaft hole 5 is made smaller than the set shaft hole diameter, and the shaft hole portion is provided with an extra thickness. After this drilling process, if necessary,
Other necessary post-processing steps such as shot blasting may also be performed. Material FW with spline grooves formed in advance in this way
is then sent to cold coining step 5. This cold coining pushes the extra wall inside the shaft hole side to the outside of the material, allowing the spline to have a predetermined accuracy. The material in which splines parallel to the gear axis have been formed in this manner is sent to a reverse slope forming step 6. Reverse gradient molding is performed using a manufacturing apparatus as shown in FIGS. 4 and subsequent figures. Next, this manufacturing apparatus will be explained. The upper die 11 is attached to an upper die mount 12 in a spring-pressed state, and the lower die 13 facing the upper die 11 is fixed to a lower die mount 14, and a bunch 15 is provided to protrude from the lower die mount 14. The lower mold! A cylindrical knock ring 116 is provided on the outer periphery of the punch 15, and an annular case 17 is fixed to the lower mold mounting base. When shaping the tooth profile in the reverse slope forming process, a large number of cam fitting holes 17H are drilled at a fixed pitch in accordance with the tooth angle and number of teeth of this gear, and the outer periphery of the cam fitting holes 17H is formed in this case 17. The inner side surface is a cam pressing surface 17F, and this cam pressing surface is a plane that is vertical and perpendicular to the longitudinal axis of the die, and a cam 21 is fitted into each hole 17H. An annular flange 18 is also mounted on the lower mold mount 14 and supported by a spring 24 attached to the lower mold mount.
The flange supports the bottom of the cam 21 that is fitted into the cam insertion hole, and the cam 21 is bolted to the flange 18. The cam 21 is finished in a flat shape with high precision so that its back surface contacts the cam pressing surface 17F, and a bottle 22 is protruded and fixed inside the lower part with the upper end inclined inward. A die pressing surface 21T having an inclination angle equal to the inclination angle of 22 is provided on the inner surface of the cam, and
Formed opposite to 2. As shown in FIGS. 6 and 7, die fitting holes 13H are formed at predetermined angles in the upper part of the lower mold 13 in alignment with a straight line toward the center of the lower mold that matches the angle between the teeth of the gear. The die insertion holes 13H have a circular cross section, and the tops thereof are cut into a planar shape and are open. Into each of the die insertion holes 13H, a die 2 having a round bar shape and whose upper surface is cut into a planar shape is inserted into each die insertion hole 13H.
3 are respectively inserted and arranged radially, and the case 17
The flat part of the die is held down to prevent the die 23 from rotating. The tip of the die 23 is provided with a hole capable of shaping each interdental groove of the gear into a predetermined reverse taper spline groove. Also, the material FW installed inside the lower mold 13 is used as the upper mold! After shaping the reverse taper spline groove with the die 23 in the descent of (2), when taking out this material FW from the lower mold, the knockout bin 1
9.20 and the knockout tube 16 so that it can be easily taken out. The knockout pin 19 quickly pushes up the flange 18 and the knockout bin 20 pushes up the knockout cylinder 16.
determine the length. As a result, after the re-die is removed outward from the teeth of the material FW, the material FW is made to protrude from the inside of the lower die. The material FW, in which a spline groove shape has been previously formed in a forging process, is set in the lower die using the manufacturing apparatus configured as described above. Next, when the upper mold is lowered, the material FW is held between the upper and lower molds by the upper mold under the pressure of the spring, and the upper surface of the cam 21 is also gripped a little later than when the material is clamped by the lowering of the upper mold. Be pressured. At this time, since the lower mold is fixed, the cam 21 and flange 18 are pushed down by the lowering of the upper mold.
As a result, the rear end of the die 23 is pushed by the tapered die pressing surface 21T of the cam, each die slides in the direction toward the center of the lower mold, and the spline groove shape of the material is formed at the die tip 23D. It is shaped into a predetermined reverse taper spline groove. Thereafter, the upper die is raised and the knockout bin 19 is pushed up, thereby also returning the flange 18. When the flange returns or rises, the cam 21 is also raised, but the bin 2 that is inclined and protrudes from the cam 21 is also raised.
2, since the rear end of the die is connected through the die, when the bin 22 is raised, the die 23 is fitted into the lower die 13 and can only slide radially;
It is something that retreats and returns. After the tip of the die is separated from the toothed part of the material FW, the material FW is pushed up from within the lower mold by the knockout bin 20 and the knockout cylinder 16 and taken out from the lower mold. [Effects of the Invention] According to the present invention, a gear having gear shifting teeth formed on its outer periphery is integrated with a boss portion having a diameter smaller than the gear diameter, and a reversely tapered spline groove is formed on the outer periphery of the boss portion. This reverse taper spline groove is formed by forging to the root of the boss part and pressing with a die matching the number of teeth, so the reverse taper spline groove can be manufactured only by the forging process, and this spline Because of the metal flow, it is strong and the effective length of the spline can be lengthened, so the overall length of the gear can be made shorter than conventional products, which has the advantage of making the transmission more compact. 4. Brief explanation of the drawings Figure 1 is a front view of the gear change gear of the present invention, Figure 2 is a sectional view,
Fig. 3 is an explanatory diagram showing the manufacturing process, Fig. 4 is a sectional view of the manufacturing equipment that performs cold inverse gradient forming, Fig. 5 is a plan view, Fig. 6 is a plan view of the lower mold, and Fig. 7 is A front view showing a part of the lower die and FIG. 8 are explanatory views of the die. 1 is a gear, 2 is a helical tooth, 3 is a boss, 4 is a spline groove, WHW is a material, 11 is an upper mold, 13 is a lower mold, 17 is a case, 18 is a flange, 21 is a cam, 22 is a bottle, 2
3 is the die patent applicant Goto Kako Co., Ltd. Figure 1 Figure 5

Claims (2)

[Claims] (1) In a synchromesh type transmission gear having teeth on the outer periphery, a boss portion is integrally formed on the gear, and reverse taper spline teeth are formed on the outer peripheral surface of the boss portion up to the root portion of the boss portion, and spline teeth A transmission gear characterized by having an effective length as long as possible. (2) A large number of dies corresponding to the number of teeth of the gear material formed by forging spline teeth parallel to the gear axis are made slidable toward the gear axis, and are inserted and supported by the lower die. A cam that is pushed down by the lowering of the upper mold facing the mold is supported so as to be able to slide vertically in a case provided on the lower mold mount, and the die abutment of each cam is abutted at the rear end of each die. A manufacturing device for a transmission gear, characterized in that the contact surface is an inclined surface such that a die moves in the direction of the gear axis when the cam is pressed down, and the spline teeth are shaped into an inversely tapered shape.