JP2021030270A - Manufacturing method of gear with crowning and manufacturing device - Google Patents

Abstract

To form crownings at a plurality of teeth which are formed at an internal peripheral face of a cylindrical workpiece by using a simple-shape metal mold.SOLUTION: An external peripheral face of a cylindrical workpiece is formed so that an outside diameter becomes large as progressing toward a center part side from both end-part sides in an axial direction. Then, by inserting the cylindrical workpiece into a metal mold whose internal peripheral face is cylindrically formed, and which has a throttle part whose inside diameter is smaller than a maximum outside diameter of the cylindrical workpiece at a part in the axial direction coaxially with the metal mold, and also making the throttle part pass therethrough by pressing the cylindrical workpiece into the axial direction, crownings are formed at a plurality of inner teeth of the cylindrical workpiece accompanied by the reduction of at least the maximum outside diameter of the cylindrical workpiece.SELECTED DRAWING: Figure 5

Description

The present invention relates to a method and an apparatus for manufacturing a gear with crowning.

Conventionally, as a method for manufacturing this type of gear with crowning, an intermediate cylindrical gear as a work of an external gear is cold forged using a cold forging device to form crowning on a plurality of teeth on the outer peripheral surface. A forging method for manufacturing a gear with a crowning has been proposed (see, for example, Patent Document 1). Here, the intermediate cylindrical gear is formed as a constant-thick tooth profile in which each tooth on the outer peripheral surface extends straight with substantially the same wall thickness. The forging device includes a round bar-shaped counter punch whose outer diameter is smaller than the inner diameter of the intermediate cylindrical gear, a substantially cylindrical die whose inner diameter is larger than the maximum outer diameter of the intermediate cylindrical gear, and a cylinder installed on the outer peripheral side of the die. It includes a body die holder and a die punch that presses the die downward. The counter punch has a bulging portion on the outer peripheral surface whose outer diameter increases from both sides in the axial direction toward the center, and the die has a tooth-forming tooth as a gear mold having a crowning shape on the inner peripheral surface. The die holder has a substantially tapered inner peripheral surface having a smaller inner diameter at the lower part than at the upper part. In this forging method, an intermediate cylindrical gear is arranged between the counter punch and the die, and the die is moved downward by the die punch. Then, the die is reduced in diameter by the reaction force from the die holder, and the tooth-forming teeth of the reduced die press the intermediate cylindrical gear to form crowning on each tooth on the outer peripheral surface of the intermediate cylindrical gear.

JP-A-2017-209699

In the above-mentioned forging method, the bulging portion of the counter punch of the forging device and the tooth-forming shaped tooth of the die need to be formed with high accuracy in order to form the shape of the crowning. Therefore, the configuration of the forging device becomes complicated.

The main object of the method and apparatus for manufacturing a gear with crowning of the present invention is to form crowning on a plurality of teeth formed on the inner peripheral surface or the outer peripheral surface of a tubular work by using a mold having a simple shape. And.

The method and apparatus for manufacturing a crowned gear of the present invention have adopted the following means in order to achieve the above-mentioned main object.

The method for manufacturing the first gear with crowning of the present invention is as follows.
A method for manufacturing a gear with crowning, which manufactures a gear with crowning by forming crowning on the plurality of internal teeth of a tubular work having a plurality of internal teeth formed on the inner peripheral surface.
The outer peripheral surface of the tubular work is formed so that the outer diameter increases from both end sides to the center side in the axial direction.
The tubular work is inserted coaxially with the mold into a mold having an inner peripheral surface formed in a cylindrical shape and having a drawing portion whose inner diameter is smaller than the maximum outer diameter of the tubular work in a part in the axial direction. Then, by pressing the tubular work in the axial direction and passing it through the throttle portion, crowning is applied to the plurality of internal teeth of the tubular work with reduction of at least the maximum outer diameter of the tubular work. Has a step of forming,
The gist is that.

In the first method for manufacturing a gear with crowning of the present invention, the outer peripheral surface of the tubular work is formed so that the outer diameter increases from both end sides to the center side in the axial direction. Then, the tubular work is inserted coaxially with the mold into a mold having a cylindrical inner peripheral surface and a drawing portion whose inner diameter is smaller than the maximum outer diameter of the tubular work in a part in the axial direction. By pressing the tubular work in the axial direction and passing it through the throttle portion, crowning is formed on a plurality of internal teeth of the tubular work with reduction of at least the maximum outer diameter of the tubular work. As a result, it is not necessary to use a crowning-shaped mold, and crowning can be formed on a plurality of internal teeth of the tubular work by using a simple-shaped mold. Further, by adjusting the shape of the outer peripheral surface of the tubular work, the shape of crowning can be adjusted using the same mold.

In the first method for manufacturing a gear with crowning of the present invention, in the step, the tubular work is pressed in the axial direction and passed through the throttle portion, whereby the tooth surface and the tooth tip of the plurality of internal teeth are formed. Crowning may be formed on the surface and the bottom surface of the tooth.

Further, in the first method for manufacturing a gear with crowning of the present invention, the outer peripheral surface of the tubular work is formed so that the outer diameter is maximized on one end side of the center in the axial direction. The tubular work may be passed through the throttle portion from the one end portion side. In this way, the position where the tooth thickness of the tubular work is maximized by crowning can be brought closer to the center position in the axial direction of the tubular work.

The method for manufacturing the second gear with crowning of the present invention is as follows.
A method for manufacturing a gear with crowning, which manufactures a gear with crowning by forming crowning on the plurality of external teeth of a tubular work having a plurality of external teeth formed on an outer peripheral surface.
The inner peripheral surface of the tubular work is formed so that the inner diameter becomes smaller from both end sides to the center side in the axial direction.
The tubular work so as to surround the outer periphery of one end portion in the axial direction of a mold having an outer peripheral surface formed in a cylindrical shape and having a drawing portion whose outer diameter is larger than the minimum inner diameter of the tubular work in a part in the axial direction. By arranging the tubular work and pressing the tubular work in the axial direction to pass through the throttle portion, crowning is performed on the plurality of external teeth of the tubular work with an expansion of at least the minimum inner diameter of the tubular work. Has a process of forming
The gist is that.

In the second method for manufacturing a gear with crowning of the present invention, the inner peripheral surface of the tubular work is formed so that the inner diameter becomes smaller from both end sides to the center side in the axial direction, and the outer peripheral surface is cylindrical. A tubular work is arranged so as to surround the outer circumference of one end in the axial direction of a mold having a drawn portion formed in a shape and having an outer diameter larger than the minimum inner diameter of the tubular work in a part in the axial direction. It has a step of forming crowning on a plurality of external teeth of the tubular work by pressing the work in the axial direction and passing the work through the throttle portion, thereby expanding at least the minimum inner diameter of the tubular work. As a result, it is not necessary to use a crowning-shaped mold, and crowning can be formed on a plurality of external teeth of the tubular work by using a simple-shaped mold. Further, by adjusting the shape of the inner peripheral surface of the tubular work, the shape of crowning can be adjusted using the same mold.

In the second method for manufacturing a gear with crowning of the present invention, in the step, the tubular work is pressed in the axial direction and passed through the throttle portion, whereby the tooth surface and the tooth tip of the plurality of external teeth are formed. Crowning may be formed on the surface and the bottom surface of the tooth.

Further, in the second method for manufacturing a gear with crowning of the present invention, the inner peripheral surface of the tubular work is formed so that the inner diameter is minimized on the one end side of the center in the axial direction, and the step is performed. , The tubular work may be passed through the throttle portion from the one end side. In this way, the center of crowning can be made closer to the center in the axial direction of the tubular work.

The first crowning gear manufacturing apparatus of the present invention is
A machine for manufacturing a gear with crowning, which manufactures a gear with crowning by forming crowning on the plurality of internal teeth of a tubular work having a plurality of internal teeth formed on the inner peripheral surface.
The outer peripheral surface of the tubular work is formed so that the outer diameter increases from both end sides to the center side in the axial direction.
A mold having an inner peripheral surface formed in a cylindrical shape and having a drawing portion whose inner diameter is smaller than the maximum outer diameter of the tubular work in a part in the axial direction.
A pressing portion that presses the tubular work that is inserted coaxially with the mold into the mold in the axial direction and allows the throttle portion to pass through.
To prepare
The gist is that.

In the first gear manufacturing apparatus with crowning of the present invention, the outer peripheral surface of the tubular work is formed so that the outer diameter increases from both end sides to the center side in the axial direction, and the inner peripheral surface is formed. A mold that is formed in a cylindrical shape and has a throttle portion whose inner diameter is smaller than the maximum outer diameter of the tubular work in a part in the axial direction, and a tubular work that is inserted into the mold coaxially with the mold in the axial direction. It is provided with a pressing portion that presses against and allows the throttle portion to pass through. As a result, it is not necessary to use a crowning-shaped mold, and crowning can be formed on a plurality of internal teeth of the tubular work by using a simple-shaped mold. Further, by adjusting the shape of the outer peripheral surface of the tubular work, the shape of crowning can be adjusted using the same mold.

In such a first crowning gear manufacturing apparatus, the second mold is provided, which is arranged radially inside the mold and regulates deformation of the inner peripheral surface of the tubular work, and the second mold is provided. The outer peripheral surface of the tubular work has a clearance between the tooth surface, the tooth tip surface, and the tooth bottom surface of the plurality of internal teeth of the tubular work inserted in the gap between the mold and the second mold. It may be formed. In this way, the shape of the tubular work can be made easy to flow, and crowning can be formed with higher quality.

The second crowning gear manufacturing apparatus of the present invention is
A device for manufacturing a gear with crowning, which manufactures a gear with crowning by forming crowning on the plurality of external teeth of a tubular work having a plurality of external teeth formed on an outer peripheral surface.
The inner peripheral surface of the tubular work is formed so that the inner diameter becomes smaller from both end sides to the center side in the axial direction.
A mold having a cylindrical outer peripheral surface and a drawn portion having an outer diameter larger than the minimum inner diameter of the tubular work in a part in the axial direction.
A pressing portion that presses the tubular work that is coaxially fitted to the outside of the mold in the axial direction to pass through the throttle portion, and a pressing portion.
To prepare
The gist is that.

In the second gear manufacturing apparatus with crowning of the present invention, the inner peripheral surface of the tubular work is formed so that the inner diameter becomes smaller from both end sides to the center side in the axial direction, and the outer peripheral surface is cylindrical. A mold having a drawn portion formed in a shape and having an outer diameter larger than the minimum inner diameter of the tubular work in a part in the axial direction, and a tubular work that is fitted outside the mold coaxially with the mold in the axial direction. It is provided with a pressing portion that presses against and passes the throttle portion. As a result, it is not necessary to use a crowning-shaped mold, and crowning can be formed on a plurality of external teeth of the tubular work by using a simple-shaped mold. Further, by adjusting the shape of the inner peripheral surface of the tubular work, the shape of crowning can be adjusted using the same mold.

In such a second crowning gear manufacturing apparatus, the second mold is provided on the outer side in the radial direction with respect to the mold and regulates the deformation of the outer peripheral surface of the tubular work, and the second mold is provided. The inner peripheral surface has a clearance between the tooth surface, the tooth tip surface, and the tooth bottom surface of the plurality of outer teeth of the tubular work inserted in the gap between the mold and the second mold. It may be formed. In this way, the shape of the tubular work can be made easy to flow, and crowning can be formed with higher quality.

It is an external view which shows the appearance of the tubular work 20 used in the manufacturing method of the gear with crowning as 1st Example of this invention. It is sectional drawing which shows the AA cross section in FIG. 1 of a tubular work 20. It is an external view which shows the appearance of the crowning gear 30 manufactured by the manufacturing method of the crowning gear as the 1st Example of this invention. It is sectional drawing which shows the BB cross section in FIG. 3 of the gear with crowning 30. FIG. 5 is a cross-sectional view showing a cross section of a manufacturing apparatus 40 used in a process of forming crowning on a plurality of internal teeth 22 of a tubular work 20 to manufacture a gear with crowning 30. It is an external view which shows the positional relationship between a mandrel 50 and a tubular work 20. FIG. 5 is an external view showing the appearance of a tubular work 60 used in a method for manufacturing a gear with crowning as a second embodiment of the present invention. It is sectional drawing which shows the CC cross section in FIG. 7 of a tubular work 60. It is an external view which shows the appearance of the crowning gear 70 manufactured by the manufacturing method of the crowning gear 70 as the 2nd Example of this invention. It is sectional drawing which shows the DD cross section in FIG. 9 of a gear 70 with crowning. FIG. 5 is a cross-sectional view showing a cross section of a manufacturing apparatus 80 used in a process of forming crowning on a plurality of external teeth 62 of a tubular work 60 to manufacture a gear 70 with crowning. It is an external view which shows the positional relationship between a die 90 and a tubular work 60.

Next, a mode for carrying out the present invention will be described with reference to examples.

FIG. 1 is an external view showing the appearance of a tubular work 20 used in the method for manufacturing a gear with crowning as a first embodiment of the present invention, and FIG. 2 is an external view showing an AA cross section of the tubular work 20 in FIG. It is sectional drawing which shows. As shown in FIGS. 1 and 2, the tubular work 20 is formed as a cylindrical spur gear having a plurality of internal teeth 22 on the inner peripheral side.

The plurality of internal teeth 22 each have a tooth surface 22a, a tooth tip surface 22b, and a tooth bottom surface 22c, and the tooth surface 22a, the tooth tip surface 22b, and the tooth bottom surface 22c are respectively along the axial direction of the tubular work 20. It is formed as a substantially flat surface that extends. In FIG. 2, for reference, the position of the nearest tooth bottom surface 22c is shown by a broken line. The outer diameter of the outer peripheral surface 24 of the tubular work 20 is adjusted from one end (upper end in FIG. 2) 24a and the other end (lower end in FIG. 2) 24b in the axial direction of the tubular work 20 to the tubular work 20. It is formed so as to gradually (smoothly) increase toward the position 24c formed on the other end 24b side of the center in the axial direction.

FIG. 3 is an external view showing the appearance of the crowning gear 30 manufactured by the method for manufacturing a crowning gear 30 as the first embodiment of the present invention, and FIG. 4 is a BB cross section of the crowning gear 30 in FIG. It is sectional drawing which shows. The gear with crowning 30 has crowning formed on the internal teeth 22 of the tubular work 20, and as a cylindrical spur gear having a plurality of internal teeth 32 on the inner peripheral side as shown in FIGS. 3 and 4. It is formed.

The tooth surface 32a, the tooth tip surface 32b, and the tooth bottom surface 32c of the internal tooth 32 each have crowning (formed so as to be convex from both ends in the axial direction of the crowning gear 30 toward the center (substantially the center). ing). In FIG. 4, for reference, the position of the nearest tooth bottom surface 32c is shown by a broken line. The outer diameter of the outer peripheral surface 34 of the grounding gear 30 is formed to be substantially the same from one end 34a to the other end 34b.

FIG. 5 is a cross-sectional view showing a cross section of a manufacturing apparatus 40 used in a process of forming crowning on a plurality of internal teeth 22 of a tubular work 20 to manufacture a gear with crowning 30. The left side of the alternate long and short dash line in FIG. 5 shows the state of the manufacturing apparatus 40 before forming crowning on the plurality of internal teeth 22 of the tubular work 20, and the right side of the alternate long and short dash line is the inside of the plurality of tubular workpieces 20. The state of the manufacturing apparatus 40 after forming crowning on the tooth 22 (manufacturing the gear with crowning 30) is shown. Note that FIG. 5 also shows a tubular work 20 and a gear with crowning 30.

In the embodiment, the manufacturing apparatus 40 includes a base 42, a die 44 as a mold, a mandrel 50 as a second mold, and a punch 54 as a pressing portion, as shown in FIG. The die 44 is mounted or detachably fixed on the base 42, and the inner peripheral surface is formed in a cylindrical shape. The die 44 is provided with a first portion 44a, a second portion 44b, and a third portion 44c on the inner peripheral surface in this order from the upper side in FIG. The inner diameter of the first part 44a of the die 44 is set to be slightly larger than the maximum outer diameter of the tubular work 20 (the outer diameter at the position 24c), and the inner diameter of the second part 44b of the die 44 is the tubular work 20. It is smaller than the maximum outer diameter (outer diameter at position 24c) and substantially the same as the outer diameter of the crowning gear 30 (outer diameter at one end 24a and the other 24b), and is defined as the third part of the die 44. The inner diameter of the 44c is set to be slightly larger than the inner diameter of the second portion 44b of the die 44 (for example, about 1.05 to 1.010 times the inner diameter of the second portion 44b).

The mandrel 50 is mounted or detachably fixed on the base 42, and is arranged coaxially with the die 44 and inside in the radial direction. The mandrel 50 is provided with a tooth profile portion 52 on the outer peripheral surface. FIG. 6 is an external view showing the positional relationship between the mandrel 50 and the tubular work 20. This figure corresponds to a view of the mandrel 50 and the tubular work 20 on the left side of the alternate long and short dash line in FIG. 5 as viewed from above in FIG. When the tubular work 20 is arranged so as to surround the outer periphery of the mandrel 50 as shown on the left side of the alternate long and short dash line in FIG. 5, the tooth profile portion 52 has a tooth surface of the internal teeth 22 of the tubular work 20. The tooth surface 52a, the tooth bottom surface 52b, and the tooth tip surface 52c of the tooth profile portion 52 are formed so as to face each other and have a clearance with respect to the 22a, the tooth tip surface 22b, and the tooth bottom surface 22c, respectively.

As shown in FIG. 5, the punch 54 is formed in a cylindrical shape having an outer diameter smaller than the inner diameter of the second portion 44b of the die 44 and an inner diameter larger than the outer diameter of the tooth tip surface 52c of the tooth profile portion 52 of the mandrel 50. And are arranged coaxially with respect to the dice 44 and the mandrel 50. Further, the punch 54 is configured to be movable in the vertical direction in the drawing.

Next, a step of forming crowning on a plurality of internal teeth 22 of the tubular work 20 using this manufacturing apparatus 40 to manufacture a gear with crowning 30 will be described. First, as shown on the left side of the alternate long and short dash line in FIG. 5, the tubular work 20 is inserted into the gap between the mandrel 50 and the die 44 so that the other end 24b is on the lower side in FIG. Subsequently, the punch 54 is moved downward in FIG. 5, and the tubular work 20 is pressed and moved downward in FIG. 5 by the punch 54. Then, when the tubular work 20 passes through the second portion 44b of the die 44, the portion of the tubular work 20 whose outer diameter is larger than the inner diameter of the second portion 44b of the die 44 is reduced in diameter while being pressed, and the diameter is reduced. The material of the diameterd portion flows inward in the radial direction of the tubular work 20, and crowning is formed on the tooth surface 22a, the tooth tip surface 22b, and the tooth bottom surface 22c of the internal teeth 22 of the tubular work 20, that is, crowning. The attached gear 30 is manufactured. Then, the base 42, the mandrel 50, and the die 44 are separated from each other to collect the crowning gear 30.

By doing so, it is not necessary to use a crowning-shaped mold (die or mandrel), and crowning is formed on the plurality of internal teeth 22 of the tubular work 20 by using the simple-shaped die 44 or mandrel 50. be able to. Further, by adjusting the shape of the outer peripheral surface 24 of the tubular work 20, the shape of crowning can be adjusted using the same mold.

Further, when the tubular work 20 passes through the second portion 44b of the die 44, the material of the outer peripheral portion of the tubular work 20 tends to flow inward in the radial direction and upward in FIG. By forming the maximum outer diameter portion (position 24c) on the other end 24b side of the center in the axial direction, the center of crowning (the position where the tooth thickness is maximized) is twisted in the axial direction of the crowning gear 30. It can be near the center.

Further, when the tubular work 20 is arranged so as to surround the outer periphery of the mandrel 50, the tooth profile portion 52 of the mandrel 50 has a tooth surface 22a, a tooth tip surface 22b, and a tooth bottom surface 22c of the internal teeth 22 of the tubular work 20. On the other hand, since the tooth surface 52a, the tooth bottom surface 52b, and the tooth tip surface 52c of the tooth profile portion 52 face each other and have a clearance, the tooth bottom surface 52b and the tooth tip surface 52c are the tooth tip surface 22b and the tooth bottom surface 22c. It is possible to suppress the inhibition of the flow of the material of the tubular work 20 when forming crowning on the tubular work 20 as compared with the one having no clearance with respect to the tooth.

Further, since the inner diameter of the third part 44c is larger than that of the second part 44b of the die 44, when the crowning gear 30 (member after passing through the second part 44b of the die 44) is moved downward in FIG. Friction can be suppressed.

In the embodiment, the crowning gear 30 serves as a ring gear in a planetary gear having a sun gear, a ring gear, a plurality of pinion gears that mesh with the sun gear and the ring gear, respectively, and a carrier that rotates (rotates) and revolves the plurality of pinion gears. It is composed. Here, the sun gear and each pinion gear have a plurality of external teeth, and the ring gear has a plurality of internal teeth. In general, it is desirable that the planetary gear has crowning formed on at least one of the inner teeth of the ring gear and the outer teeth of the plurality of pinion gears (all pinion gears). In the embodiment, by forming the crowning on the inner teeth of the ring gear, it is possible to reduce the amount of work and the cost as compared with the case where the crowning is formed on the outer teeth of all the pinion gears.

In the method for manufacturing the crowning gear 30 of the first embodiment described above, the outer peripheral surface 24 of the tubular work 20 is formed so that the outer diameter increases from one end 24a and the other end 24b toward the position 24c. To. Then, the die 44 has a second portion 44b whose inner peripheral surface is formed in a cylindrical shape and whose inner diameter is smaller than the maximum outer diameter (outer diameter at the position 24c) of the tubular work 20 in a part in the axial direction. By inserting the tubular work 20 coaxially with 44 and pressing the tubular work 20 in the axial direction to pass through the second part 44b, the tubular work is tubular with a reduction in the outer diameter of at least the position 24c. Crowning is formed on the plurality of internal teeth 22 of the work 20. As a result, it is not necessary to use a crowning-shaped mold (die or mandrel), and crowning can be formed on a plurality of internal teeth 22 of the tubular work 20 by using a simple-shaped die 44 or mandrel 50. Further, by adjusting the shape of the outer peripheral surface of the tubular work 20, the shape of crowning can be adjusted using the same mold.

Further, in the manufacturing apparatus 40 for the crowning gear 30 of the first embodiment described above, the outer diameter of the outer peripheral surface 24 of the tubular work 20 increases from one end 24a and the other end 24b toward the position 24c. A die 44 having a second portion 44b having an inner peripheral surface formed in a cylindrical shape and a part having an inner diameter smaller than the maximum outer diameter (outer diameter at the position 24c) of the tubular work 20 in the axial direction. The die 44 includes a punch 54 that presses the cylindrical work 20 inserted coaxially with the die 44 in the axial direction and passes the second portion 44b. As a result, it is not necessary to use a crowning mold, and crowning can be formed on a plurality of internal teeth 22 of the tubular work 20 by using a die 44 or a mandrel 50 having a simple shape. Further, by adjusting the shape of the outer peripheral surface of the tubular work 20, the shape of crowning can be adjusted using the same mold.

In the first embodiment, the manufacturing apparatus 40 has a mandrel 50 arranged coaxially and radially inward with respect to the die 44, but may not have the mandrel 50.

In the first embodiment, when the tubular work 20 is arranged so as to surround the outer periphery of the mandrel 50, the tooth profile portion 52 of the mandrel 50 of the manufacturing apparatus 40 has the tooth surface 22a and the teeth of the internal teeth 22 of the tubular work 20. The front surface 22b and the tooth bottom surface 22c are formed so that the tooth surface 52a of the tooth profile portion 52, the tooth bottom surface 52b, and the tooth tip surface 52c face each other and have a clearance. However, the above-mentioned clearance may be formed at least on the tooth surface 52a of the mandrel 50. When the mandrel 50 has the above-mentioned clearance only on the tooth surface 52a, the manufactured gear with crowning 30 has crowning formed only on the tooth surface 32a of the internal tooth 32.

In the first embodiment, the position 24c of the outer peripheral surface 24 of the tubular work 20 is formed on the other end 24b side of the center in the axial direction of the tubular work 20, but the shaft of the tubular work 20 It may be formed near the center in the direction.

In the first embodiment, the tubular work 20 (gear with crowning 30) is a cylindrical spur gear having a plurality of internal teeth 22 (internal teeth 32) on the inner peripheral side, but the internal teeth are provided on the inner peripheral side. Any cylindrical gear having a cylindrical shape may be used, and for example, a cylindrical helical gear having a plurality of internal teeth on the inner peripheral side may be used.

FIG. 7 is an external view showing the appearance of the tubular work 60 used in the method for manufacturing a gear with crowning as a second embodiment of the present invention, and FIG. 8 shows a CC cross section of the tubular work 60 in FIG. 7. It is sectional drawing which shows. As shown in FIGS. 7 and 8, the tubular work 60 is formed as a cylindrical spur gear having a plurality of external teeth 62 on the outer peripheral side.

The plurality of external teeth 62 each have a tooth surface 62a, a tooth tip surface 62b, and a tooth bottom surface 62c, and the tooth surface 62a, the tooth tip surface 62b, and the tooth bottom surface 62c are respectively along the axial direction of the tubular work 60. It is formed as a substantially flat surface that extends. In FIG. 8, for reference, the position of the nearest tooth bottom surface 62c is shown by a broken line. The inner diameter of the inner peripheral surface 64 of the tubular work 60 is from one end (upper end in FIG. 8) 64a and the other end (lower end in FIG. 8) 64b in the axial direction of the tubular work 60. It is formed so as to gradually (smoothly) become smaller toward the position 64c formed on the other end 64b side of the center in the axial direction.

FIG. 9 is an external view showing the appearance of the crowning gear 70 manufactured by the method for manufacturing the crowning gear 70 as the second embodiment of the present invention, and FIG. 10 is a DD cross section of the crowning gear 70 in FIG. It is sectional drawing which shows. The gear with crowning 70 has crowning formed on the outer teeth 62 of the tubular work 60, and is formed as a cylindrical spur gear having a plurality of outer teeth 72 on the outer peripheral side as shown in FIGS. 9 and 10. Has been done.

The tooth surface 72a, the tooth tip surface 72b, and the tooth bottom surface 72c of the external tooth 72 each have crowning (formed so as to be convex from both ends in the axial direction of the crowning gear 70 toward the center (substantially the center). ing). In FIG. 10, for reference, the position of the nearest tooth bottom surface 72c is shown by a broken line. The inner diameter of the inner peripheral surface 74 of the grounding gear 70 is formed to be substantially the same from one end 74a to the other end 74b.

FIG. 11 is a cross-sectional view showing a cross section of a manufacturing apparatus 80 used in a process of forming crowning on a plurality of external teeth 62 of a tubular work 60 to manufacture a gear with crowning 70. The left side of the alternate long and short dash line in FIG. 11 shows the state of the manufacturing apparatus 80 before forming crowning on the plurality of external teeth 62 of the tubular work 60, and the right side of the alternate long and short dash line is the outside of the tubular work 60. The state of the manufacturing apparatus 80 after forming crowning on the tooth 62 (manufacturing the gear 30 with crowning) is shown. In addition, FIG. 11 also shows a tubular work 60 and a gear 70 with crowning.

In the embodiment, the manufacturing apparatus 80 includes a base 82, a mandrel 84 as a mold, a die 90 as a second mold, and a punch 94 as a pressing portion, as shown in FIG. The mandrel 84 is mounted or detachably fixed on the base 82, and the outer peripheral surface is formed in a cylindrical shape. The mandrel 84 includes a first part 84a, a second part 84b, and a third part 84c on the outer peripheral surface in this order from the upper side in FIG. The outer diameter of the first part 84a of the mandrel 84 is set to be slightly smaller than the minimum inner diameter of the tubular work 60 (inner diameter at the position 64c), and the outer diameter of the second part 84b of the mandrel 84 is the tubular work 60. It is larger than the minimum inner diameter (inner diameter at position 64c) and substantially the same as the inner diameter of the crowning gear 70 (outer diameter at one end 74a and the other end 74b), and is outside the third part 84c of the mandrel 84. The diameter is set to be slightly smaller than the outer diameter of the second part 84b of the mandrel 84 (for example, about 0.990 to 0.995 times the inner diameter of the second part 44b).

The die 90 is mounted or detachably fixed on the base 82, and is arranged coaxially with respect to the mandrel 84 and radially outward. The die 90 is provided with a tooth profile portion 92 on the inner peripheral surface. FIG. 12 is an external view showing the positional relationship between the die 90 and the tubular work 60. This figure corresponds to a view of the die 90 and the tubular work 60 on the left side of the alternate long and short dash line in FIG. 11 as viewed from above in FIG. The tooth profile portion 92 is formed on the outer teeth 62 of the tubular work 60 when the tubular work 60 is arranged so as to be surrounded by the inner circumference of the die 90 as shown on the left side of the alternate long and short dash line in FIG. The tooth surface 62a, the tooth tip surface 62b, and the tooth bottom surface 62c are formed so that the tooth surface 92a, the tooth bottom surface 92b, and the tooth tip surface 92c of the tooth profile portion 92 face each other and have a clearance, respectively.

As shown in FIG. 11, the punch 94 is formed in a cylindrical shape having an inner diameter larger than the outer diameter of the second portion 84b of the mandrel 84 and an outer diameter smaller than the inner diameter of the tooth tip surface 92c of the tooth profile portion 92 of the die 90. And are arranged coaxially with respect to the mandrel 84 and the dice 90. Further, the punch 94 is configured to be movable in the vertical direction in the drawing.

Next, a step of forming crowning on a plurality of external teeth 62 of the tubular work 60 using this manufacturing apparatus 80 to manufacture a gear 70 with crowning will be described. First, as shown on the left side of the alternate long and short dash line in FIG. 11, the tubular work 60 is inserted into the gap between the mandrel 84 and the die 90 so that the other end 64b is on the lower side in FIG. Subsequently, the punch 94 is moved downward in FIG. 11, and the tubular work 60 is pressed and moved downward in FIG. 11 by the punch 94. Then, when the tubular work 60 passes through the second portion 84b of the mandrel 84, the portion of the tubular work 60 whose inner diameter is smaller than the outer diameter of the second portion 84b of the mandrel 84 is expanded and expanded while being pressed. The material of the diameter portion flows outward in the radial direction of the tubular work 60, and crowning is formed on the tooth surface 62a, the tooth tip surface 62b, and the tooth bottom surface 62c of the outer teeth 62 of the tubular work 60, that is, crowning. The gear 70 is manufactured. Then, the base 82, the mandrel 84, and the die 90 are separated from each other to collect the crowning gear 70.

By doing so, it is not necessary to use a crowning-shaped mold (mandrel or die), and crowning is formed on a plurality of external teeth 62 of the tubular work 60 by using a simple-shaped mandrel 84 or die 90. be able to. Further, by adjusting the shape of the inner peripheral surface 64 of the tubular work 60, the shape of crowning can be adjusted using the same mold.

Further, when the tubular work 60 passes through the second portion 84b of the mandrel 84, the material of the inner peripheral portion of the tubular work 60 tends to flow outward in the radial direction and upward in FIG. 11, so that the tubular work 60 tends to flow upward. By forming the minimum inner diameter portion (position 64c) on the other end 64b side of the center in the axial direction of the crowning, the center of crowning (the position where the tooth thickness is maximized) is twisted in the axial direction of the gear 70 with crowning. It can be near the center.

Further, when the tubular work 60 is arranged so as to be surrounded by the inner circumference of the die 90, the tooth profile portion 92 of the die 90 has a tooth surface 62a, a tooth tip surface 62b, and a tooth bottom surface of the outer teeth 62 of the tubular work 60. Since the tooth surface 92a, the tooth bottom surface 92b, and the tooth tip surface 92c of the tooth profile portion 92 face each other and have a clearance with respect to 62c, the tooth bottom surface 92b and the tooth tip surface 92c are the tooth tip surface 62b and the tooth. It is possible to suppress the inhibition of the flow of the material of the tubular work 60 when forming crowning on the tubular work 60, as compared with the one having no clearance with the bottom surface 62c.

Further, since the outer diameter of the third part 84c is smaller than that of the second part 84b of the mandrel 84, the gear with crowning 70 (member after passing through the second part 84b of the mandrel 84) is moved downward in FIG. Friction can be suppressed.

In the method for manufacturing the crowning gear 70 of the second embodiment described above, the inner peripheral surface 64 of the tubular work 60 is formed so that the inner diameter becomes smaller from one end 64a and the other end 64b toward the position 64c. An axial end of a mandrel 84 having a second portion 84b whose outer peripheral surface is formed in a cylindrical shape and whose outer diameter is larger than the minimum inner diameter (inner diameter at position 64c) of the tubular work 60 in a part in the axial direction. By arranging the tubular work 60 so as to surround the outer circumference and pressing the tubular work 60 in the axial direction to pass through the second portion 84b, the inner diameter of at least the position 64c of the tubular work 60 is expanded. It has a step of forming crowning on a plurality of external teeth 62 of the tubular work 60. As a result, it is not necessary to use a crowning-shaped mold (mandrel or die), and crowning can be formed on a plurality of external teeth 62 of the tubular work 60 by using a simple-shaped mandrel 84 or die 90. Further, by adjusting the shape of the inner peripheral surface 64 of the tubular work 60, the shape of crowning can be adjusted using the same mold.

Further, in the manufacturing apparatus 80 for the crowning gear 70 of the second embodiment described above, the inner peripheral surface 64 of the tubular work 60 has an inner diameter that decreases from one end 64a and the other end 64b toward the position 64c. Mandrel 84 and a mandrel 84 having a second portion 84b whose outer peripheral surface is formed in a cylindrical shape and whose outer diameter is larger than the minimum inner diameter (inner diameter at position 64c) of the tubular work 60 in a part in the axial direction. It is provided with a punch 94 that presses the cylindrical work 60 that is fitted coaxially with the mandrel 84 in the axial direction to pass the second portion 84b. As a result, it is not necessary to use a crowning mold, and crowning can be formed on a plurality of external teeth 62 of the tubular work 60 by using a mandrel 84 or a die 90 having a simple shape. Further, by adjusting the shape of the inner peripheral surface 64 of the tubular work 60, the shape of crowning can be adjusted using the same mold.

In the second embodiment, the manufacturing apparatus 80 has the dies 90 arranged coaxially and radially outward with respect to the mandrel 84, but may not have the dies 90.

In the second embodiment, the tooth profile portion 92 of the die 90 of the manufacturing apparatus 80 and the tooth surface 62a of the outer teeth 62 of the tubular work 60 when the tubular work 60 is arranged so as to surround the outer periphery of the die 90. It is assumed that the tooth surface 92a of the tooth profile portion 92, the tooth bottom surface 92b, and the tooth tip surface 92c are formed so as to face each other and have a clearance with respect to the tooth tip surface 62b and the tooth bottom surface 62c, respectively. However, the above-mentioned clearance may be formed at least on the tooth surface 92a of the die 90. When the die 90 has the above-mentioned clearance only on the tooth surface 92a, the manufactured gear with crowning 70 has crowning formed only on the tooth surface 72a of the external tooth 72.

In the second embodiment, the position 64c of the inner peripheral surface 64 of the tubular work 60 is formed on the other end 64b side of the center in the axial direction of the tubular work 60. It may be formed near the center in the axial direction.

In the second embodiment, the tubular work 60 (gear with crowning 70) is a cylindrical spur gear having a plurality of external teeth 62 (external teeth 72) on the outer peripheral side, but is a cylinder having external teeth on the outer peripheral side. It may be a cylindrical gear, for example, a cylindrical helical gear having a plurality of external teeth on the outer peripheral side.

The correspondence between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem will be described. In the first embodiment, the tubular work 20 corresponds to the "cylindrical work", the crowning gear 30 corresponds to the "crowning gear", the manufacturing apparatus 40 corresponds to the "manufacturing apparatus", and the die 44 corresponds to the "manufacturing apparatus". The mandrel 50 corresponds to the "mold", the mandrel 50 corresponds to the "second mold", and the punch 54 corresponds to the "pressing portion". Further, in the second embodiment, the tubular work 60 corresponds to the "cylindrical work", the gear with crowning 70 corresponds to the "gear with crowning", the manufacturing apparatus 80 corresponds to the "manufacturing apparatus", and the mandrel 84. Corresponds to the "mold", the die 90 corresponds to the "second mold", and the punch 94 corresponds to the "pressing portion".

Regarding the correspondence between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem, the invention described in the column of the means for solving the problem in the examples is carried out. Since it is an example for specifically explaining the form for solving the problem, the elements of the invention described in the column of means for solving the problem are not limited. That is, the interpretation of the invention described in the column of means for solving the problem should be performed based on the description in the column, and the examples are the inventions described in the column of means for solving the problem. It is just a concrete example.

Although the embodiments for carrying out the present invention have been described above with reference to examples, the present invention is not limited to these examples, and various embodiments are used without departing from the gist of the present invention. Of course, it can be done.

The present invention can be used in the gear manufacturing industry and the like.

20,60 Cylindrical workpiece, 22,32 internal teeth, 24,34 outer peripheral surface, 30,70 gear with crowning, 40,80 manufacturing equipment, 42,82 base, 44,90 dies, 50,84 mandrel, 52, 92 tooth profile, 54,94 punch, 62,72 outer teeth, 64,74 inner peripheral surface.

Claims (10)

A method for manufacturing a gear with crowning, which manufactures a gear with crowning by forming crowning on the plurality of internal teeth of a tubular work having a plurality of internal teeth formed on the inner peripheral surface.
The outer peripheral surface of the tubular work is formed so that the outer diameter increases from both end sides to the center side in the axial direction.
The tubular work is inserted coaxially with the mold into a mold having an inner peripheral surface formed in a cylindrical shape and having a drawing portion whose inner diameter is smaller than the maximum outer diameter of the tubular work in a part in the axial direction. Then, by pressing the tubular work in the axial direction and passing it through the throttle portion, crowning is applied to the plurality of internal teeth of the tubular work with reduction of at least the maximum outer diameter of the tubular work. Has a step of forming,
Manufacturing method of gears with crowning. The method for manufacturing a gear with crowning according to claim 1.
In the step, the tubular work is pressed in the axial direction and passed through the throttle portion to form crowning on the tooth surface, the tooth tip surface, and the tooth bottom surface of the plurality of internal teeth.
Manufacturing method of gears with crowning. The method for manufacturing a gear with crowning according to claim 1 or 2.
The outer peripheral surface of the tubular work is formed so that the outer diameter is maximized on one end side of the center in the axial direction.
In the step, the tubular work is passed through the throttle portion from the one end side.
Manufacturing method of gears with crowning. A method for manufacturing a gear with crowning, which manufactures a gear with crowning by forming crowning on the plurality of external teeth of a tubular work having a plurality of external teeth formed on an outer peripheral surface.
The inner peripheral surface of the tubular work is formed so that the inner diameter becomes smaller from both end sides to the center side in the axial direction.
The tubular work so as to surround the outer periphery of one end portion in the axial direction of a mold having an outer peripheral surface formed in a cylindrical shape and having a drawing portion whose outer diameter is larger than the minimum inner diameter of the tubular work in a part in the axial direction. By arranging the tubular work and pressing the tubular work in the axial direction to pass through the throttle portion, crowning is performed on the plurality of external teeth of the tubular work with an expansion of at least the minimum inner diameter of the tubular work. Has a process of forming
Manufacturing method of gears with crowning. The method for manufacturing a gear with crowning according to claim 4.
In the step, the tubular work is pressed in the axial direction and passed through the throttle portion to form crowning on the tooth surface, the tooth tip surface, and the tooth bottom surface of the plurality of external teeth.
Manufacturing method of gears with crowning. The method for manufacturing a gear with crowning according to claim 4 or 5.
The inner peripheral surface of the tubular work is formed so that the inner diameter is minimized on the one end side of the center in the axial direction.
In the step, the tubular work is passed through the throttle portion from the one end side.
Manufacturing method of gears with crowning. A machine for manufacturing a gear with crowning, which manufactures a gear with crowning by forming crowning on the plurality of internal teeth of a tubular work having a plurality of internal teeth formed on the inner peripheral surface.
The outer peripheral surface of the tubular work is formed so that the outer diameter increases from both end sides to the center side in the axial direction.
A mold having an inner peripheral surface formed in a cylindrical shape and having a drawing portion whose inner diameter is smaller than the maximum outer diameter of the tubular work in a part in the axial direction.
A pressing portion that presses the tubular work that is inserted coaxially with the mold into the mold in the axial direction and allows the throttle portion to pass through.
Equipment for manufacturing gears with crowning. The apparatus for manufacturing a gear with crowning according to claim 7.
A second mold, which is arranged radially inside the mold and regulates deformation of the inner peripheral surface of the tubular work, is provided.
The outer peripheral surface of the second mold is provided with respect to the tooth surface, the tooth tip surface, and the tooth bottom surface of the plurality of internal teeth of the tubular work inserted in the gap between the mold and the second mold. Formed to have clearance,
Manufacturing equipment for gears with crowning. A device for manufacturing a gear with crowning, which manufactures a gear with crowning by forming crowning on the plurality of external teeth of a tubular work having a plurality of external teeth formed on an outer peripheral surface.
The inner peripheral surface of the tubular work is formed so that the inner diameter becomes smaller from both end sides to the center side in the axial direction.
A mold having a cylindrical outer peripheral surface and a drawn portion having an outer diameter larger than the minimum inner diameter of the tubular work in a part in the axial direction.
A pressing portion that presses the tubular work that is coaxially fitted to the outside of the mold in the axial direction to pass through the throttle portion, and a pressing portion.
Equipment for manufacturing gears with crowning. The apparatus for manufacturing a gear with crowning according to claim 9.
A second mold, which is arranged radially outside the mold and regulates deformation of the outer peripheral surface of the tubular work, is provided.
The inner peripheral surface of the second mold is provided with respect to the tooth surface, the tooth tip surface, and the tooth bottom surface of the plurality of external teeth of the tubular work inserted in the gap between the mold and the second mold. Formed to have clearance,
Manufacturing equipment for gears with crowning.