JP2007175718A - Gear on ground of metallic plate and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a gear by using a plastically working means on the ground of a metallic plate. <P>SOLUTION: This method of manufacturing the gear comprises: a blank cutting-down stage (A) where a blank 9 having a prescribed shape is cut down by using prescribed dies 90, 91 on the ground of the metallic plate; and a tooth-form forming stage (B) where the root part 112 of a tooth which is changed so that the cross-sectional shape has a gentle round part is formed by using a punch 80 and a die 81 which have a prescribed tooth form on the ground of the blank 9 which is cut down into the prescribed shape in the blank cutting-down stage (A) is formed and also simultaneously a tooth part 11 having an addendum part 111 having a sharp cross-sectional shape in the tip part is formed integrally and simultaneously. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a gear formed so as to have a predetermined tooth profile by applying a plastic working means such as a press forming means to a metal plate material, and a method for manufacturing the same.

Generally, a gear having a small tooth width value is formed by forming a gear piece having a predetermined gear shape by applying a punching means to a metal plate material, and welding the gear piece to another metal plate material. A predetermined gear is formed by joining them using, for example. By the way, in the formation of the gear by this conventional punching means or the like, there is a problem that the material around the punched parts is discarded and the material yield is not good. Moreover, since the joining process by a welding means is required, there exists a problem of causing the fall of the component precision by a thermal strain, etc. In order to solve such problems, there is a gear forming method in which a gear is formed by applying a plastic working means such as a deep drawing forming means to a gear based on a metal plate material. It is mentioned by Kaihei 8-39185 gazette etc.
JP-A-8-39185

  By the way, in the processing by the deep drawing method of the metal plate material like the above-mentioned conventional one, there is a problem that “drawing wrinkles” occur around the tooth profile forming portion to be drawn. In particular, when the tooth profile needs to be sharpened, the occurrence of the “drawing wrinkle” is a concern. In order to solve such problems, in the above-described tooth profile forming step, the deep tip forming process is performed so that the shape of the tooth tip portion deeply involved in meshing with other gears has a sharp shape. In the molding around the tooth root part, which does not contribute much, the metal plate material is used as the basis so that the shape changes slowly in order to make the material flow (movement) smoothly during plastic deformation. An object (problem) of the present invention is to provide a gear and a manufacturing method thereof.

  In order to solve the above problems, the following measures are taken in the present invention. That is, in the first invention according to the first aspect of the present invention, with respect to the gear formed on the basis of the metal plate material, the metal plate material having a predetermined plate thickness is used as a basis, and a predetermined drawing process is applied thereto. The tooth tip portion formed from the pitch circle has a tooth profile shape having a sharp shape over the entire tooth width direction at the tip portion from the pitch circle, and the tooth width direction from the pitch circle to the tooth root portion. In this case, a configuration is adopted in which the tooth profile is formed so that the tooth profile gradually disappears.

  Next, in the second invention which is the invention described in claim 2, regarding a method of manufacturing a gear based on a metal plate material, a predetermined mold is used on the basis of the metal plate material. A blank cutting step for cutting a blank, and a tooth root portion that changes the blank cut into the predetermined form so that the cross-sectional shape has a sag portion using a punch and a die having a predetermined tooth shape And a tooth forming step for forming a tooth portion including a tooth tip portion having a sharp cross-sectional shape over the entire tooth width direction.

  Next, in the third invention which is the invention described in claim 3, regarding the gear manufacturing method based on the metal plate material described in claim 2, between the punch and the die used in the tooth forming step. The radial relative positional relationship around the tooth tip forming portion is set so that the outer diameter value of the punch is larger than the inner diameter value of the die by a predetermined amount.

  According to the first invention, in a gear that performs rolling motion, such as a planetary gear, the tooth tip part mainly contributes to the meshing engagement, so that only the tooth tip part has a sharp shape. On the other hand, the tooth portion has a “sag” in the shape change so that the change in the cross-sectional shape is gradual so as to increase the overall strength and rigidity. As a result, it is possible to efficiently form (manufacture) a gear that is light and has excellent strength and rigidity.

  According to the second invention, by adopting the above process, a gear having a small tooth width value can be efficiently formed (manufactured) based on the metal plate material. This makes it possible to form gears mainly for rolling motion, such as planetary gears, on the basis of thin metal plate materials, and to efficiently produce light gears with excellent strength and rigidity. It can be formed (manufactured).

  Further, according to the third invention, since the predetermined amount of overlap portion is formed in the radial direction between the punch and the die forming the tooth tip portion, the end surface of the tooth tip portion has the tooth width. It is formed in a vertical shape throughout, and the shape of the tooth tip portion contributing to the meshing is molded so as to have a sharper form.

  The best mode for carrying out the present invention will be described with reference to FIGS. The present embodiment relates to a gear formed by plastic working means based on a metal plate and a manufacturing method thereof. In particular, the manufacturing method includes the steps shown in FIG. That is, the manufacturing method is based on a predetermined metal plate 99 such as a steel plate, and a blank 9 having a predetermined size and form is cut out by using predetermined mold sets 90 and 91 for this. The cutting step (A), the blank portion 9 cut into the predetermined shape, the tooth root portion that changes so as to have a sag portion whose cross-sectional shape is gentle using the punch 80 and the die 81 having the predetermined tooth shape shape, and It is basically composed of a tooth forming step (B) comprising a drawing forming process in which the tooth portion 11 having a sharp cross-sectional shape over the entire tooth width is formed integrally and simultaneously. It is what.

  By adopting such a process, the gear 1 based on a metal plate as shown in FIG. 2 is formed (manufactured) through plastic working means including press forming means. The configuration of the gear 1 will be described. As shown in FIG. 2, this is formed on the basis of a plate-like blank 9, and forms a base 15 having a flat plate shape, and forms, for example, an involute tooth-shaped base circle on the base 15. It consists of a base circle portion 12 and a plurality of tooth portions 11 provided at equal intervals around the circumference of the base circle portion 12. And these each part is integrally formed on the basis of the plate-shaped blank 9 of 1 sheet.

  In such a configuration, the shape of the tooth portion 11 is such that, as shown in FIG. 2, for example, the tooth tip portion 111 is formed vertically over the entire tooth width (H). The base portion 112 is formed so that the surface gradually changes from the deepest portion 115 in the tooth width (H) direction toward the surface 121 of the base circle portion 12. Accordingly, in the tooth portion 11, the tooth profile forming portion exists only in a part of the tooth width (H) direction in the portion inside the pitch circle (pitch line PP). That is, as shown in FIG. 2, in the deepest portion 115 in the tooth width (H) direction, the tooth profile forming portion exists only in the portion from the substantially pitch line (PP) to the tooth tip portion 111, and the tooth surface forming portion of the outermost surface portion. All tooth shapes are present only where they coincide with the surface 121 of the base circle 12. By adopting such a configuration, the strength and rigidity of the tooth portion 11 can be increased while using a thin plate material.

  Next, in forming the tooth tip portion 111 that contributes to the meshing engagement of the teeth, the tooth tip portion 111 should be as vertical as possible so that the tooth portion is formed over the entire tooth width (H) direction. A forming process is performed so as to have. In the present embodiment, as shown in FIG. 3, a pair of punch and die in which the outer diameter value (d) of the punch 80 is slightly larger than the inner diameter value (D) of the die 81. The drawing process is performed using That is, as shown in FIG. 3B, the relational expression d = D + t is established. Specifically, in FIG. 3B, the value of t is set to a value of about 0.5 mm, and the tip end portion of the inner diameter vertical wall portion of the die 81 that contributes to the formation of the tooth tip portion 111. The R shape is restricted to a value of R = 0.3 mm or less. By adopting such a value, the end face of the tooth tip portion 111 has a vertical surface throughout the tooth width (H) direction by the drawing process in the step (B) of FIG. That is, the tooth profile in the portion on the tooth tip side from the pitch line (PP) in FIG. 2 is sharp throughout the entire tooth width direction.

  By providing such an overlap margin (t), the vertical wall portion in the tooth tip portion 111 is kept in a sharp shape, and the thickness around the R portion at the root portion of the vertical wall portion is the minimum necessary value. Will be able to secure. As a result, the material can be smoothly flowed from the tooth tip portion 111 to the tooth root portion 112 during the drawing process, and the strength and rigidity of the entire tooth portion 11 can be ensured. It becomes like this. In this manner, the tooth tip portion 111 has a sharp shape over the entire tooth width direction, and the tooth root portion 112 has the sag portion 119 formed in one drawing process. In order to achieve this, preferably, a press force is gradually applied using a servo press device, and a stop state at the bottom dead center of the press head is provided for at least 0.3 seconds. desirable.

  By adopting such a process, in the present embodiment, the gear having the tooth portion 11 having a small tooth width value (H) can be efficiently formed (manufactured) based on the metal plate material. I can do it now. In particular, in a gear that performs rolling motion, such as a planetary gear, the tooth tip portion 111 mainly contributes to the meshing engagement. Therefore, only the tooth tip portion 111 has a shape throughout the tooth width direction. The shape of the tooth root 112 is made to be “sag” in the shape of the tooth root 112 so that the cross-sectional shape changes gradually and the overall strength and rigidity are increased. did. As a result, it is possible to efficiently form (manufacture) a gear that is light and has excellent strength and rigidity. Further, in such a configuration, for example, as shown in FIG. 3B, a predetermined amount of overlap portion (in the radial direction) between the punch 80 forming the tooth tip portion 111 and the die 81 ( t), the end surface of the tooth tip 111 is formed vertically over the entire tooth width (H), which contributes to the meshing, and the tooth tip from the pitch line (PP) The shape over the portion 111 can be formed in a sharp shape over the entire tooth width (H) direction. As a result, it is possible to efficiently form a tooth tip portion having an end surface necessary for meshing engagement.

It is process explanatory drawing which shows the whole process of this invention. It is the perspective view and half sectional view which show the whole structure of the gear manufactured by this invention. It is sectional drawing which shows the formation process of the tooth tip part by the punch and die | dye which make the principal part among the processes concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gear 11 Tooth part 111 Tooth part 112 Tooth part 115 Deepest part 119 Sag part 12 Base circle part 121 Surface 15 Base 80 Punch 81 Die 9 Blank 90 Mold 91 Mold 99 Metal plate material

Claims (3)

  It is formed by applying a predetermined drawing process to a metal plate material having a predetermined plate thickness, and has a sharp shape over the entire tooth width direction from the pitch circle to the tip portion. A gear having a tooth profile formed from the pitch circle and the tooth root portion so as to gradually disappear in the tooth width direction.   A blank cutting step of cutting a blank having a predetermined shape by using a predetermined mold on the basis of a metal plate material, and a punch and a die having a predetermined tooth profile shape from the blank cut to the predetermined shape A tooth forming step for forming a tooth base portion having a tooth base portion having a sharp cross-sectional shape over the entire tooth width direction, and a tooth base portion that changes so as to have a sag portion having a gentle cross-sectional shape using A method of manufacturing a gear based on a metal plate characterized by the above.   In the manufacturing method of the gear based on the metal plate material according to claim 2, the radial relative positional relationship around the tooth tip forming portion between the punch and the die used in the tooth forming step is expressed by the outer diameter of the punch. A gear manufacturing method based on a metal plate material, characterized in that the value is set to be a predetermined amount larger than the value of the inner diameter of the die.

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