JP2004268045A - Die for forming gear and method for manufacturing gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die for forming a gear by which the gear can be formed by using a thin wall material to be formed compared with a material for the conventional one, and a method for manufacturing the gear. <P>SOLUTION: When a cylinder material 52 is pressed by a punch 40 and it is pushed into a punch thrust-in hole 26 formed to a die 30, the cylinder material 52 is moved over a forming tooth 33 on the die side projected from the inner peripheral face of the punch thrust-in hole 26 and it is deformed inwardly in the die 10 for forming the gear. Then, unevenness is formed on the inner peripheral face of the cylinder material 52 by a forming tooth 43 on the punch side inserted to the inside of the cylinder material 52. Here, the forming tooth 43 on the punch side is projected toward the tooth bottom of the forming tooth 33 on the die side. Accordingly, a part of the cylinder material 52 sandwiched between the forming tooth 33 on the die side and the forming tooth 43 on the punch side is formed into a corrugated shape. The equalization of the wall thickness of the tooth and the tooth bottom is realized compared with the conventional one. As a result, the gear can be formed by using the thinner wall cylinder material 52 than that of the conventional one. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gear forming mold for forming a gear on a cylindrical material to be formed, and a gear manufacturing method using the gear forming mold.
[0002]
[Prior art]
Conventionally, a gear formed by this type of gear molding mold has a structure having a plurality of teeth only on one of the outer peripheral surface and the inner peripheral surface of a cylindrical molding material. (See Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-96136 (FIGS. 2 and 11)
[0004]
[Problems to be solved by the invention]
However, in the above-described material, a difference in wall thickness between a plurality of teeth of the material to be molded and a root portion between adjacent teeth becomes large. For this reason, in order to secure the thickness of the tooth bottom portion, the thickness of the portion other than the gear forming portion of the material to be molded becomes excessively large, resulting in a problem that the molded product becomes heavy.
[0005]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a gear molding die and a gear manufacturing method capable of molding a gear using a material to be molded that is thinner than conventional ones.
[0006]
[Means for Solving the Problems]
A gear molding die (10) according to the invention of claim 1 made to achieve the above object comprises a punch (40) and a die (30), and a cylindrical material (52) is punched (40). ) To be pressed into the punch entry hole (26) provided in the die (30), and the material to be molded (52) is formed by a plurality of die side forming teeth (33) protruding from the inner peripheral surface of the punch entry hole (26). A gear molding die (10) for forming a gear portion (59) on the outer peripheral surface of the punch (40) on the outer peripheral surface of a portion (42) of the punch (40) that can be inserted inside the molding material (52). Is characterized in that a plurality of punch side molding teeth (43) protruding toward the root of the die side molding teeth (33) are provided.
[0007]
According to a second aspect of the present invention, in the gear molding die (10) according to the first aspect, the punch (40) has a material pressing surface (45) for pressing one end surface of the material to be molded (52). It is characterized by where it is provided.
[0008]
According to a third aspect of the present invention, in the gear molding die (10) according to the first or second aspect, the root diameter (D4) of the die side molding tooth (33) is the gear molding in the material to be molded (52). It is characterized by being smaller than the outer diameter (D6) of the portion (57).
[0009]
According to a fourth aspect of the present invention, in the gear molding die (10) according to any one of the first to third aspects, an outer diameter of the material to be molded (52) is formed on the inner peripheral surface of the punch entry hole (26). It is characterized in that a tapered portion (26T) for reducing the diameter of (D6) to the root diameter (D4) of the die-side molded tooth (33) is provided.
[0010]
According to a fifth aspect of the present invention, there is provided a method of manufacturing a gear (60), wherein a cylindrical workpiece (52) is pressed by a punch (40) and is pressed into a punch entry hole (26) provided in a die (30). The gear (60) manufacturing method of forming the gear part (59) on the outer peripheral surface of the material (52) to be molded by the plurality of die side forming teeth (33) protruding from the inner peripheral surface of the punch entry hole (26) In the punch (40), a plurality of punch-side molding teeth (43) are formed on the outer peripheral surface of the portion (42) to be inserted inside the material to be molded (52). 33) and the punch side forming tooth (43), the material (52) is shaped into a corrugated shape.
[0011]
The invention of claim 6 is the gear (60) manufacturing method according to claim 5, wherein one end surface of the material to be molded (52) is located proximal to the punch side molding teeth (43) in the punch (40). A material pressing surface (45) for pressing the material is provided, and the material to be molded is placed inside the die side molding teeth (33) while pressing one end surface of the material to be molded (52) by the material pressing surface (45). (52) is characterized by being pushed in.
[0012]
A seventh aspect of the present invention is the method of manufacturing a gear (60) according to the sixth aspect, wherein after the step of inserting the punch-side molding teeth (43) into the molding material (52), the molding material (52). Is characterized in that a step of pushing the gear forming portion (57) into the inside of the die side forming tooth (33) is performed.
[0013]
According to an eighth aspect of the present invention, in the method for manufacturing the gear (60) according to the seventh aspect, the material pressing surface (45) is provided after the step of pressing the gear forming portion (57) into the inside of the die side forming tooth (33). Is characterized in that the step of further pressing the material to be molded (52) is performed.
[0014]
[Action and effect of the invention]
<Invention of Claims 1 and 5>
In the inventions of claims 1 and 5, when the cylindrical material to be molded (52) is pressed by the punch (40) and pressed into the punch entry hole (26) provided in the die (30), the material to be molded (52) However, it rides on the die side forming teeth (33) protruding from the inner peripheral surface of the punch entry hole (26) and deforms inward. Then, an unevenness | corrugation is formed in the internal peripheral surface of a to-be-molded material (52) by the punch side molding tooth (43) inserted inside the to-be-molded material (52). Here, since the punch side molding tooth (43) protrudes toward the bottom of the die side molding tooth (33), the die side molding tooth (33) and the punch side molding tooth of the material to be molded (52). The portion sandwiched between (43) has a corrugated shape, and the teeth and teeth are compared to those in which a plurality of teeth are formed only on either the inner peripheral surface or the outer peripheral surface of the material to be molded as in the past. The thickness of the bottom portion is made uniform. Thereby, it becomes possible to shape | mold a gearwheel using the to-be-shaped material (52) thinner than before.
[0015]
<Invention of Claims 2 and 6>
According to invention of Claim 2 and 6, a to-be-molded raw material (52) is pressed with the raw material press surface (45) in a punch (40), die side molding teeth (33), punch side molding teeth (43), The material to be molded (52) can be spread to every corner of the molding region (R1) between, and the molding quality is improved.
[0016]
<Invention of Claim 3>
In the gear molding die (10) according to claim 3, the root diameter (D4) of the die side molding tooth (33) is larger than the outer diameter (D6) of the gear molding portion (57) of the molding material (52). Since it is small, the material to be molded (52) is pressed against the die side molding tooth (33) by the reaction force of the material to be molded (52) itself, and the material to be molded (52) to every corner of the die side molding tooth (33). Will spread and mold quality will improve.
[0017]
<Invention of Claim 4>
In the gear molding die (10) according to claim 4, the material to be molded (52) is reduced in diameter by passing through the tapered portion (26T), and the material to be molded (52) is formed on the die side by the reaction force. The material to be molded (52) reaches the corners of the die side molding teeth (33) by being pressed against the teeth (33), and the molding quality is improved.
[0018]
<Invention of Claim 7>
In the manufacturing method of the gear (60) according to claim 7, after the punch-side molding teeth (43) are inserted into the molding material (52), the gear molding portion (57) of the molding material (52) is on the die side. Since it is pushed inside the forming tooth (33), when the material to be formed (52) rides on the die side forming tooth (33) and is deformed inside, the punch side forming is performed inside the material to be formed (52). The teeth (43) are in a ready state, whereby the flow inside the molding material (52) is simplified, and the molding accuracy on the die side molding teeth (33) side is improved.
[0019]
<Invention of Claim 8>
In the manufacturing method of the gear (60) according to claim 8, following the step of pushing the gear forming portion (57) of the material to be formed (52) into the inside of the die side forming tooth (33), the material pressing surface (45) is used. Since the molding material (52) is further pressed, the molding material (52) reaches all corners of the die-side molding teeth (33), and the molding quality is improved.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
FIG. 1 shows a gear manufacturing apparatus 20 of the present embodiment. The gear manufacturing apparatus 20 includes an upper base 21 and a lower base 22 that face each other in the vertical direction. For example, the upper base 21 is guided by a guide post 23 and moves up and down. The die 30 fixed to the lower base 22 and the punch 40 fixed to the upper base 21 constitute the gear molding die 10 according to the present invention.
[0021]
The die 30 is formed by overlapping a tooth part forming die 32 on the upper surface of a base part forming die 31. A lower holder 24 for fixing the die 30 to the lower base 22 is overlaid on the upper surface of the die 30. A punch 40 can be inserted into a punch insertion hole 26 having a circular cross section formed in communication with the base portion forming die 31, the tooth portion forming die 32 and the lower holder 24.
[0022]
A knockout pin 34 is fitted in the punch insertion hole 26 in the base part molding die 31. A cylindrical material 52, which will be described later, is pushed into the back side of the punch insertion hole 26 while being sandwiched between the knockout pin 34 and the punch 40. Further, a burring punch 35 is fitted in a through hole formed in the shaft core portion of the knockout pin 34.
[0023]
As shown in FIGS. 2 and 4, a plurality of die-side molding teeth 33 are formed at the lower end portion of the inner peripheral surface of the punch entry hole 26 in the tooth portion molding die 32. Each die-side molded tooth 33 has a ridge whose ridgeline extends in the vertical direction. And as shown in FIG. 5, the shape of the shaping | molding area | region R1 by the die | dye side shaping | molding tooth | gear 33 is the shape of an involute gear. Moreover, the width | variety and height are gradually small as the upper end part of these die side shaping teeth 33 goes upwards (refer to Drawing 2).
As shown in FIG. 3A, a taper portion 26 </ b> T whose diameter is reduced as it approaches the die side molding tooth 33 is provided in a portion of the punch entry hole 26 above the die side molding tooth 33. .
[0024]
On the other hand, as shown in FIG. 1, the punch 40 includes a cylindrical portion 41 that hangs down from the upper holder 25, and a tooth forming feature 42 that protrudes downward from the lower end surface of the cylindrical portion 41. As shown in FIG. 2, the tooth forming feature 42 is slightly reduced in diameter toward the lower end. Further, a piercing hole 48 into which the tip of the burring punch 35 pierces is formed on the lower end surface of the tooth forming feature 42.
[0025]
As shown in FIGS. 2 and 4, a plurality of punch side forming teeth 43 are formed on the upper end portion of the outer peripheral surface of the tooth forming body 42. As shown in FIG. 5, these punch-side formed teeth 43 protrude toward the bottom of the die-side formed teeth 33, thereby forming a forming region between the punch-side formed teeth 43 and the die-side formed teeth 33. R1 has a wave shape.
[0026]
As shown in FIG. 6, the tip diameter D <b> 2 of the punch side molding tooth 43 is smaller than the tip diameter D <b> 3 of the die side molding tooth 33. Further, as shown in FIG. 2, the outer diameter D <b> 10 of the lower end surface of the cylindrical portion 41 in the punch 40 is larger than the tip diameter D <b> 3 of the punch side molding tooth 43, and the edge portion of the lower end surface of the cylindrical portion 41 Is a material pressing surface 45 for pressing an upper end surface of a cylindrical material 52 to be described later.
[0027]
Now, a method for manufacturing the involute gear 60 (see FIG. 8) using the gear manufacturing apparatus 20 described above as a part of the manufacturing process will be described. As the first step, the disc material 50 shown in FIG. 7A is punched from the sheet metal. At this time, a round hole 51 is punched in the center of the disc material 50.
[0028]
As a second step, the above-described disc material 50 is drawn to form the cylindrical material 52 shown in FIG. 7B. Here, the cylindrical material 52 has a cylindrical shape with one end having a bottom wall 54 at one end of the cylindrical wall 53, and the edge of the round hole 51 in the disc material 50 is cylindrical at the center of the bottom wall 54. An emboss 55 squeezed toward the inside of the wall 53 is formed. The cylindrical wall 53 is formed by connecting a small diameter portion 56 and a large diameter portion 57 having different diameters with a tapered portion 58, and the small diameter portion 56 is disposed on the bottom wall 54 side.
[0029]
As shown in FIG. 6, both the inner diameter D5 and the outer diameter D6 of the large diameter portion 57 are larger than the tooth tip diameter D3 of the die side forming tooth 33. Further, the outer diameter D6 of the large diameter portion 57 is larger than the root diameter D4 of the die side molding tooth 33.
[0030]
The outer diameter of the small diameter portion 56 is smaller than the tip diameter D3 of the die side molding tooth 33. Therefore, even if the small diameter portion 56 is pushed into the inside of the die side forming tooth 33, no gear is formed on the small diameter portion 56. Further, in this second step, after the cylindrical material 52 is drawn from the disk material 50, the cylindrical wall 53 of the cylindrical material 52 is pressed in the axial direction, so that the outer diameter D6 of the large diameter portion 57 and The thickness of the large-diameter portion 57 that is the difference from the inner diameter D5 is larger than the thickness of the disc material 50. Specifically, if the thickness of the disc material 50 is, for example, 4.0 mm, the outer diameter D6 of the large diameter portion 57 is 84.2 mm, the inner diameter D5 is 75.8 mm, and the thickness of the large diameter portion 57 is It is 8.3 mm (= D6-D5).
[0031]
Next, as a third step, the cylindrical material 52 is set in the punch entry hole 26 in the gear manufacturing apparatus 20. Specifically, the cylindrical material 52 is inserted into the punch insertion hole 26 from the bottom wall 54 side, and is engaged with the upper open end of the punch insertion hole 26. Then, the gear manufacturing apparatus 20 is operated. Then, the punch 40 is lowered, and the tooth forming feature 42 in the punch 40 is inserted inside the cylindrical material 52 so that the bottom wall 54 of the cylindrical material 52 is sandwiched between the tooth forming feature 42 and the knockout pin 34. Become.
[0032]
The punch 40 pushes the cylindrical material 52 into the deep part of the punch insertion hole 26 while maintaining the state where the bottom wall 54 is sandwiched. Then, the diameter of the cylindrical material 52 is reduced by being reduced by passing the large diameter portion 57 of the cylindrical material 52 through the tapered portion 26 </ b> T provided in the punch insertion hole 26. As a result, an internal stress in the expansion direction is generated in the large diameter portion 57, and the large diameter portion 57 is in close contact with the inner peripheral surface of the punch insertion hole 26. At this time, the upper end portion of the large-diameter portion 57 is brought into contact with the material pressing surface 45 of the punch 40 to restrict deformation of the large-diameter portion 57 extending in the axial direction. Thereby, in the process in which the cylindrical material 52 is pushed into the back side of the punch insertion hole 26, the thickness of the large-diameter portion 57 increases.
[0033]
Further, when the punch 40 pushes in the cylindrical material 52, the small diameter portion 56 of the cylindrical material 52 is inserted into the inside of the die side molding teeth 33 as shown in FIG. 3A, and further, FIG. As shown in FIG. 5, the large diameter portion 57 of the cylindrical material 52 rides on the die side molding tooth 33 along the inclination of the upper end portion of the die side molding tooth 33. Here, since the large-diameter portion 57 is in a state in which the internal stress in the expanding direction is generated as described above, the material constituting the large-diameter portion 57 is securely in close contact with the die-side molding teeth 33.
[0034]
The large-diameter portion 57 deformed inward by riding on the die-side molded teeth 33 is pressed against the punch-side molded teeth 43 that have been waiting inside the large-diameter portion 57. As described above, in this embodiment, when the cylindrical material 52 rides on the die-side molded teeth 33 and deforms inward, the punch-side molded teeth 43 are waiting inside the cylindrical material 52. The flow inside the material 52 is simplified, and the molding accuracy on the die side molding tooth 33 side is improved.
[0035]
Here, since the punch side molding tooth 43 protrudes toward the bottom of the die side molding tooth 33, the large diameter portion 57 is sandwiched between the punch side molding tooth 43 and the die side molding tooth 33, As shown in FIG. Thereby, compared with the case where a several tooth | gear is simply shape | molded on the outer surface of the large diameter part 57, the plate | board thickness of a gear formation part is equalized. Moreover, the raw material which comprises the large diameter part 57 is pushed back by the die | dye side shaping | molding tooth | gear 33, and it closely_contact | adheres to the whole from the tip of the die side shaping | molding tooth | gear 33 to a tooth bottom, and molding quality improves.
[0036]
When the large diameter portion 57 reaches the lower end portion of the die side forming tooth 33, the lower end portion of the large diameter portion 57 is pressed against the upper end surface 31A (see FIG. 4) of the base portion forming die 31. Even in this state, the punch 40 is further pushed into the back side of the punch insertion hole 26. Thereby, the upper surface of the large diameter portion 57 is pushed by the material pressing surface 45 of the punch 40, and the material constituting the large diameter portion 57 is formed between the tooth bottom of the die side molding tooth 33 and the upper surface 31 A of the base portion molding die 31. Go all the way to the corner. As a result, as shown in FIG. 8, the tooth tip of the gear portion 59 formed on the cylindrical material 52 is reliably formed to the lower end portion (the portion indicated by reference numeral 59 </ b> A in FIG. 8) in the tooth width direction.
[0037]
When the cylindrical material 52 is taken out from the punch entry hole 26, an involute gear 60 having a gear portion 59 on the outer surface is completed as shown in FIG.
[0038]
As described above, according to the gear molding die 10 of the present embodiment, a portion of the cylindrical material 52 sandwiched between the die side molding teeth 33 and the punch side molding teeth 43 has a corrugated shape, which is conventional. Compared with the case where a plurality of teeth are formed only on either the inner peripheral surface or the outer peripheral surface of the material to be molded, the thickness of the teeth and the bottom of the teeth can be made uniform. As a result, the involute gear 60 can be manufactured using the cylindrical material 52 that is thinner than the conventional one. Further, the cylindrical material 52 sandwiched between the die side molding teeth 33 and the punch side molding teeth 43 is pressed by the material pressing surface 45 of the punch 40, so that the gap between the die side molding teeth 33 and the die side molding teeth 33 is reached. The cylindrical material 52 can be spread to every corner of the molding region R1, and the molding quality is improved.
[0039]
<Other embodiments>
The present invention is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present invention, and various other than the following can be made without departing from the scope of the invention. It can be changed and implemented.
(1) The cylindrical material 52 of the above embodiment has a cylindrical shape with one end, but the present invention is applied to a gear manufacturing method and a gear molding mold for forming a cylindrical shape with both ends open. Also good.
[0040]
(2) In the above-described embodiment, the inner diameter of the large-diameter portion 57 in the cylindrical material 52 is larger than the tip diameter of the die-side molded teeth 33. It may be smaller than the tooth tip diameter.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a gear manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is a partial cross-sectional view of a gear forming die. FIG. 3 (A) is a state immediately before a cylindrical material is formed with teeth. Partial sectional view of the gear molding die (B) Partial sectional view of the gear molding die in which the teeth of the cylindrical material are molded. FIG. 4 is a partial perspective view of the gear molding die. Sectional view of gear molding die at section A-A in 3 (B) [FIG. 6] Sectional view comparing the size of cylindrical material, die side molding teeth and punch side molding teeth [FIG. 7] (A) Perspective view of disc material (B) Perspective view of cylindrical material [Fig. 8] Perspective view of completed gear [Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Gear shaping | molding die 26 ... Punch entry hole 26T ... Tapered part 30 ... Dies 32 ... Tooth part shaping | molding die 33 ... Die side shaping | molding tooth 40 ... Punch 42 ... Tooth formation form 43 ... Punch side shaping | molding tooth 45 ... Material pressing surface 52 ... Cylindrical material (molded material)
57 ... Large diameter part (gear forming part)
59 ... Gear part

Claims (8)

A punch (40) and a die (30) are provided, and a cylindrical workpiece (52) is pressed by the punch (40) and is pushed into a punch entry hole (26) provided in the die (30). A gear molding die (10) for molding a gear portion (59) on the outer peripheral surface of the material (52) to be molded by a plurality of die side molding teeth (33) protruding from the inner peripheral surface of the punch entry hole (26). Because
A plurality of punch sides projecting toward the bottom of the die-side molding teeth (33) are formed on the outer peripheral surface of a portion (42) of the punch (40) that can be inserted into the molding material (52). A gear molding die (10), characterized in that it is provided with molding teeth (43). The gear molding die (10) according to claim 1, wherein the punch (40) is provided with a material pressing surface (45) for pressing one end surface of the material to be molded (52). ). The root diameter (D4) of the die side forming tooth (33) is smaller than the outer diameter (D6) of the gear forming portion (57) of the material to be formed (52). The gear molding die (10) as described. In the inner peripheral surface of the punch entry hole (26), the outer diameter (D6) of the material to be molded (52) is reduced in diameter to the root diameter (D4) of the die-side molding tooth (33). The gear molding die (10) according to any one of claims 1 to 3, wherein a tapered portion (26T) is provided. A cylindrical shaped material (52) is pressed by a punch (40), pressed into a punch entry hole (26) provided in a die (30), and a plurality of protrusions protruding from the inner peripheral surface of the punch entry hole (26). A manufacturing method of a gear (60), in which a gear part (59) is formed on the outer peripheral surface of the material to be molded (52) by the die side molding teeth (33) of
A plurality of punch side molding teeth (43) are formed on an outer peripheral surface of a portion (42) inserted inside the molding material (52) of the punch (40), and the die side molding teeth (33) are formed. ) And the punch side forming teeth (43), the material (52) to be formed is formed into a corrugated shape. A material pressing surface (45) for pressing one end surface of the material to be molded (52) is provided closer to the base end side than the punch side molding teeth (43) in the punch (40),
The material to be molded (52) is pushed inside the die side molding teeth (33) while pressing one end surface of the material to be molded (52) by the material pressing surface (45). A manufacturing method of the gear (60) according to claim 5. After the step of inserting the punch side molding tooth (43) into the molding material (52), the gear molding part (57) of the molding material (52) is placed inside the die side molding tooth (33). The manufacturing method of the gear (60) according to claim 6, wherein a pressing step is performed. The step of further pressing the material to be molded (52) with the material pressing surface (45) is performed after the step of pushing the gear forming portion (57) into the inside of the die side forming tooth (33). A manufacturing method of the gear (60) according to claim 7.

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