JP2016120679A - Gear production method, mold and gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cost of a gear.SOLUTION: A gear shape member 12 forming a gear, is molded in a molding step. The gear shape member 12 comprises: a frame-state body part 16 forming an annular shape; plural teeth 18 formed on an outer peripheral part of the body part 16; and plural undercut parts 20 formed on tip ends of the plural teeth 18 and on tooth bottom faces between the plural teeth 18 respectively. In mold open of the mold, a first mold 32 for molding an outer peripheral part of the body part 16 containing the plural teeth 18 and plural undercut parts 20 is attached to an outer peripheral part of the body part 16, and in the state, a second mold 34 for molding an inner peripheral part of the body part 16 is separated from the gear shape member 12, and a space 62 (release space) is secured in the body part 16. In a release step, the gear shape member 12 is deformed toward the inner space (62) side of the body part 16, and released from the first mold 32.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a gear manufacturing method, a mold, and a gear.

  2. Description of the Related Art Conventionally, there is a gear provided with a disk-shaped main body having a hole at the center and a plurality of teeth formed on the outer periphery of the main body and arranged in the circumferential direction of the main body. Also, in this type of gear, a plurality of undercut portions that are recessed toward the radially inner side of the main body portion are formed on at least one of the tooth tips and the bottom surfaces between the plurality of teeth, respectively. There is.

  Such a gear having a plurality of undercut portions is generally divided into a first mold for forming the outer peripheral portion of the main body portion including a plurality of teeth and a plurality of undercut portions, and an axial direction of the main body portion. It is molded by a mold including a second mold and a third mold for molding both axial end portions of the section (see, for example, Patent Document 1).

  In this mold, the first mold is multi-divided in the circumferential direction, and when releasing the gear, each of the multi-divided divided molds is moved radially outward so that the undercut portion and the first mold are moved. Interference with one mold is avoided.

Japanese Patent No. 4707523

  However, as described above, when the first mold for molding the outer peripheral portion of the main body is divided into multiple parts, the structure of the mold becomes complicated and the cost increases. In addition, it is conceivable to form a portion to be an undercut portion by cutting after molding, but in this case as well, the cost increases due to an increase in the manufacturing process.

  This invention is made | formed in view of the said subject, The objective is to provide the manufacturing method of a gear, a metal mold | die, and a gear which can reduce cost.

  In order to achieve the above object, a method for manufacturing a gear according to claim 1 includes a frame-shaped main body portion having a ring shape or a C-shape having a separating portion in a part of a circumferential direction, and the main body portion. A plurality of teeth formed on the outer peripheral portion and arranged in the circumferential direction of the main body portion, tooth tips of the plurality of teeth, tooth bottom surfaces between the plurality of teeth, and tooth tips and teeth of the plurality of teeth A plurality of undercut portions each formed on at least one of the tooth surfaces between the bottom surfaces and recessed toward the radially inner side of the main body portion, and forming a tooth profile member constituting the gear using a mold The molding step and the mold, the first mold for molding the outer peripheral portion of the main body portion including the plurality of teeth and the plurality of undercut portions is mounted on the outer peripheral portion of the main body portion. Separating the second mold for forming the inner peripheral portion of the main body from the tooth profile member, Comprising of a mold opening step to secure a space on the inside, and a releasing step of releasing from the first mold while deforming the toothed member to the space side of the inside of the main body portion.

  According to this gear manufacturing method, the main body portion of the tooth profile member constituting the gear is formed in a frame shape instead of a conventional disk shape. And in a mold release process, using the space inside the main-body part formed in the mold opening process, it releases from a 1st type | mold, deform | transforming a tooth profile member to the space side inside a main-body part. Therefore, there is no need to divide the first mold that molds the outer peripheral part of the main body part or to cut the part that becomes the undercut part after molding, thus simplifying the structure of the mold for manufacturing the tooth profile member In addition, an increase in the manufacturing process can be suppressed. As a result, the cost can be reduced.

  The gear manufacturing method according to claim 2 is the gear manufacturing method according to claim 1, wherein in the molding step, the main body is formed in an annular shape, and in the mold releasing step, the tooth profile member is formed. In this method, the tooth profile member is released from the first mold while being deformed to the inner space side of the main body portion over the entire circumference of the main body portion.

  According to this gear manufacturing method, since the main body of the tooth profile member is formed in an annular shape, the rigidity of the tooth profile member can be ensured.

  The gear manufacturing method according to claim 3 is the gear manufacturing method according to claim 1, wherein in the molding step, the main body is formed in a C shape, and in the mold release step, the tooth profile member is formed. In this method, the tooth profile member is released from the first mold while being deformed in order from one end to the other end in the circumferential direction of the main body toward the space inside the main body.

  According to this gear manufacturing method, by forming the main body portion in a C shape, it is possible to easily release the mold while deforming the tooth profile member into a spiral shape in the mold release step.

  The gear manufacturing method according to claim 4 is the gear manufacturing method according to any one of claims 1 to 3, wherein a filler is filled inside the main body after the mold release step. And a secondary forming step of forming a supporting member integrally with the tooth profile member by the filler.

  According to this gear manufacturing method, the tooth profile member can be supported by the support member from the inside by integrally forming the support member inside the body portion of the tooth profile member. Thereby, the rigidity of a tooth profile member can be improved.

  The gear manufacturing method according to claim 5 is the gear manufacturing method according to claim 4, wherein in the molding step, the main body portion is formed in a C shape, and in the secondary molding step, the filler is formed. Is formed in the separation part, and a connection part is formed by connecting both ends in the circumferential direction of the main body part with a part of the filler.

  According to this gear manufacturing method, it is possible to suppress the deformation of the C-shaped body part by forming the connection part that connects the circumferential ends of the body part, and to ensure the rigidity of the tooth profile member. Can do.

  In order to achieve the above object, a mold according to claim 6 is an annular shape or a frame-shaped main body portion having a C-shape having a separating portion in a circumferential direction, and the main body portion. A plurality of teeth formed on the outer peripheral portion and arranged in the circumferential direction of the main body portion, tooth tips of the plurality of teeth, tooth bottom surfaces between the plurality of teeth, and tooth tips and teeth of the plurality of teeth A plurality of undercut portions each formed on at least one of the tooth surfaces between the bottom surfaces and recessed toward the radially inner side of the main body portion, and among the tooth-shaped members constituting the gear, the plurality of teeth and A first mold having a molding surface for molding the outer peripheral portion of the main body portion including the plurality of undercut portions; and a second mold having a molding surface for molding the inner peripheral portion of the main body portion.

  According to this mold, since it is possible to realize a gear manufacturing method including the above-described forming process, split mold process, and mold release process, the cost can be reduced.

  In order to achieve the above object, the gear according to claim 7 is a ring-shaped body or a frame-shaped main body portion having a C-shape having a separating portion in a circumferential direction, and an outer periphery of the main body portion. A plurality of teeth formed in a portion and arranged in a circumferential direction of the main body, a tooth tip of the plurality of teeth, a tooth bottom surface between the plurality of teeth, and a tooth tip and a tooth bottom surface of the plurality of teeth A plurality of undercut portions that are respectively formed on at least one of the tooth surfaces between the two and are recessed toward the radially inner side of the main body portion.

  According to this gear, since it is manufactured by the above-described gear manufacturing method, the cost can be reduced.

  A gear according to an eighth aspect is the gear according to the seventh aspect, wherein the main body portion, the plurality of teeth, and a tooth profile member having the plurality of undercut portions, and the inside of the main body portion are filled. A support member formed integrally with the tooth profile member by a filler.

  According to this gear, since the support member is integrally formed inside the main body portion of the tooth profile member, the tooth profile member can be supported by the support member from the inside. Thereby, the rigidity of a tooth profile member is securable.

  A gear according to a ninth aspect is the gear according to the eighth aspect, wherein the main body portion is formed in a C shape, and a part of the filler is filled in the separation portion, and the main body portion is formed. It further includes a connecting portion that connects both ends in the circumferential direction.

  According to this gear, since both ends in the circumferential direction of the main body portion are connected by the connecting portion, deformation of the main body portion formed in a C shape can be suppressed, and the rigidity of the tooth profile member can be ensured.

It is a perspective view showing the state where the gear of the first embodiment was fixed to the shaft. It is a perspective view containing the longitudinal cross-section of the gearwheel and shaft of FIG. It is a perspective view which shows the tooth profile member of FIG. FIG. 2 is an enlarged longitudinal sectional view of main parts of a gear and a shaft of FIG. 1. It is a 1st explanatory view explaining the manufacturing method of the gear of Drawing 1. It is a 2nd explanatory view explaining the manufacturing method of the gear of Drawing 1. It is a perspective view which shows the state by which the gearwheel of 2nd embodiment was fixed to the shaft. It is a perspective view which shows the tooth profile member of FIG. It is a perspective view which shows a mode that the tooth profile member of FIG. 7 is released from a 1st type | mold. It is a principal part expanded longitudinal cross-sectional view of the gearwheel of FIG. It is a perspective view which shows the modification of the gearwheel of 2nd embodiment.

[First embodiment]
First, a first embodiment of the present invention will be described.

  The gear 10 according to the first embodiment of the present invention shown in FIGS. 1 and 2 is configured as a worm wheel as an example, and includes a tooth profile member 12 and a support member 14.

  The tooth profile member 12 constitutes the outer peripheral portion of the gear 10, and has a main body portion 16 and a plurality of teeth 18. The main body portion 16 is formed in a frame shape having an annular shape. The plurality of teeth 18 are formed on the outer peripheral portion of the main body portion 16 and are arranged in the circumferential direction of the main body portion 16. The plurality of teeth 18 are formed to be slightly inclined with respect to the axial direction of the main body portion 16.

  A plurality of undercut portions 20 are respectively formed on the tooth tips of the plurality of teeth 18 and the bottom surface between the plurality of teeth 18. The plurality of undercut portions 20 are each formed in a concave shape (curved shape as an example) that is recessed toward the radially inner side of the main body portion 16.

  As shown in FIGS. 3 and 4, an annular flange portion 22 is formed on the inner peripheral portion of the main body portion 16 along the inner peripheral portion. The flange portion 22 is formed with the axial direction of the main body portion 16 as the thickness direction. A plurality of projecting portions 24 projecting from the front side and the back side of the flange portion 22 are formed in the flange portion 22 at intervals in the circumferential direction of the flange portion 22.

  The support member 14 is formed in a disk shape. As will be described later, the support member 14 is formed of a resin filled inside the main body portion 16 in the secondary molding step, and is formed integrally with the tooth profile member 12.

  As shown in FIGS. 2 and 4, in the state where the support member 14 is formed integrally with the tooth profile member 12, the flange portion 22 and the protrusion 24 described above are embedded in the support member 14 and integrated with the support member 14. It has become. As shown in FIG. 2, the support member 14 is also integrally formed with the shaft 26, and the tip end portion of the shaft 26 is embedded and integrated in the center of the support member 14. Yes.

  Next, the metal mold | die which concerns on 1st embodiment of this invention is demonstrated.

  A mold 30 according to the first embodiment of the present invention shown in FIGS. 5 and 6 is a tooth profile member 12 which is a primary molded product among the gears 10 including the above-described tooth profile member 12 and the support member 14. The first mold 32 and the second mold 34 are provided. The first die 32 has a molding surface 36 for molding the outer peripheral portion of the main body portion 16 including the plurality of teeth 18 and the plurality of undercut portions 20 described above, and is formed in an annular shape.

  The second mold 34 has a fixed mold 38 and a movable mold 40. The fixed mold 38 and the movable mold 40 are divided in the axial direction of the main body 16 described above, and have molding surfaces 42 and 44 for molding the inner peripheral portion of the main body 16, respectively. The molding surfaces 42 and 44 of the fixed mold 38 and the movable mold 40 are formed in an annular shape, and are arranged on the radially inner side of the molding surface 36 of the first mold 32 to face the molding surface 36. Is done.

  The fixed die 38 is formed with a molding surface 46 for molding one axial end portion of the main body portion 16, and the movable die 40 is formed with a molding surface 48 for molding the other axial end portion of the main body portion 16. Is formed. Further, molding surfaces 50 and 52 for molding the flange portion 22 are formed on the fixed mold 38 and the movable mold 40, respectively. In the mold 30, a space surrounded by the plurality of molding surfaces described above forms a cavity 54 for molding the above-described tooth profile member 12.

  The fixed die 38 is provided with a cylindrical push pin 56 that can slide in the dividing direction of the fixed die 38 and the movable die 40. The push pin 56 is provided at a position corresponding to the radially inner portion of the flange portion 22 described above. Further, a protruding locking portion 58 is formed on the outer peripheral portion of the first die 32, and a protruding locking portion 60 is also formed on the fixed die 38. The locked portion 60 is provided on the movable mold 40 side with respect to the locking portion 58 in the dividing direction of the fixed mold 38 and the movable mold 40. The locking portion 58 and the locked portion 60 are opposed to each other with a gap in the dividing direction of the fixed mold 38 and the movable mold 40.

  Next, the gear manufacturing method according to the first embodiment of the present invention will be described.

(Molding process)
First, as shown in the upper diagram of FIG. 5, the mold 30 is in a state where the first mold 32 (tooth mold insert) and the second mold 34 (fixed mold 38 and movable mold 40) are clamped. Molten resin is injected into the cavity 54 formed inside the inside. Then, the molten resin injected into the cavity 54 is cooled, whereby the tooth profile member 12 that is a primary molded product is formed.

(Mold opening process)
Subsequently, as shown in the lower diagram of FIG. 5, the movable mold 40 is raised and the mold 30 is opened. The movable mold 40 is separated from the tooth profile member 12 by being raised. Further, when the mold 30 is opened, as shown in the upper diagram of FIG. 6, the push pin 56 is raised, and the tooth profile member 12 is raised together with the first die 32 by the push pin 56. . When the first die 32 is raised, the locking portion 58 formed on the first die 32 is locked to the locked portion 60 formed on the fixed die 38, and the rising of the first die 32 is restricted. Is done.

  Further, when the tooth profile member 12 is raised until the locking portion 58 is locked to the locked portion 60, the tooth profile member 12 is positioned above the molding surface of the fixed mold 38, and the tooth profile member 12 and the fixed mold 38. Are separated. Thus, in a state where the tooth profile member 12 and the fixed mold 38 are separated, a space 62 (relief space 62) is secured inside the main body portion 16 of the tooth profile member 12.

(Release process)
Then, as shown in the lower diagram of FIG. 6, the push pin 56 is further raised while the first die 32 is mounted on the outer peripheral portion of the main body portion 16. At this time, since the rising of the first mold 32 is restricted by the locking portion 58 being locked to the locked portion 60, the tooth profile member 12 is pressed upward against the first mold 32. The

  At this time, as described above, since the space 62 is secured inside the main body portion 16 of the tooth profile member 12, the tooth profile member 12 pressed by the push pin 56 is deformed toward the inner space 62 side. The tooth profile member 12 is released from the first mold 32 while being deformed toward the inner space 62 side. Further, since the tooth profile member 12 is pressed by the cylindrical extrusion pin 56, it is released from the first mold 32 while being deformed toward the space 62 inside the main body portion 16 over the entire circumference of the main body portion 16. The

  In this mold release step, it is desirable that the tooth profile member 12 is released from the first mold 32 in a semi-solid state before the tooth profile member 12 is completely solidified. In the mold release step, the tooth mold member is brought into a semi-solid state, so that the tooth mold member is released all at once. The tooth profile member 12 that is the primary molded product is formed as described above.

(Secondary molding process)
Subsequently, after the tooth profile member 12 is formed as described above, the tooth profile member 12 is integrated with the support member 14 using another mold. That is, in the secondary molding step of molding the support member 14, resin is filled inside the main body portion 16, and the support member 14 is formed integrally with the tooth profile member 12 by this resin. Further, when the support member 14 is formed, the shaft 26 is integrated with the support member 14.

  Next, the operation and effect of the first embodiment of the present invention will be described.

  As described above in detail, according to the first embodiment of the present invention, the body portion 16 of the tooth profile member 12 constituting the gear 10 is formed in a frame shape instead of a disc shape. In the mold release step, the space 62 inside the main body 16 formed in the mold opening step is used to release the first profile 32 from the first mold 32 while deforming the tooth profile member 12 toward the space 62 inside. Therefore, it is not necessary to divide the first die 32 for molding the outer peripheral portion of the main body portion 16 into multiple parts or to cut the portion that becomes the undercut portion 20 after molding. The structure can be simplified, and an increase in the manufacturing process can be suppressed. As a result, the cost can be reduced.

  Moreover, since the main-body part 16 of the tooth profile member 12 is formed in an annular shape in the molding step, the rigidity of the tooth profile member 12 can be ensured.

  Furthermore, in the secondary molding step, by forming the support member 14 integrally inside the body portion 16 of the tooth profile member 12, the tooth profile member 12 can be supported by the support member 14 from the inside thereof. Thereby, the rigidity of the tooth profile member 12 can be improved.

  Next, a modification of the first embodiment of the present invention will be described.

  In the first embodiment described above, the undercut portions 20 are formed on the tooth tips of the plurality of teeth 18 and the tooth bottom surfaces between the plurality of teeth 18, respectively. It may be formed only on one of the root surfaces between the tip and the plurality of teeth 18.

  The undercut portion 20 is formed on at least one of the tooth tips of the plurality of teeth 18, the tooth bottom surface between the plurality of teeth 18, and the tooth surface between the tooth tip and the tooth bottom surface of the plurality of teeth 18. May be.

  Moreover, although the gearwheel 10 is provided with the support member 14, when the rigidity of the tooth-shaped member 12 can be ensured, for example in the state solidified completely, the support member 14 may be omitted.

  In the mold release process, it is desirable that the tooth profile member 12 is released from the first mold 32 in a semi-solid state before the tooth profile member 12 is completely solidified. When the deformation of the member 12 is easy, the tooth profile member 12 may be released while the tooth profile member 12 is completely solidified.

  Further, in the mold release step, the tooth profile member 12 is released from the first mold 32 by being pushed by the push pin 56, but the first mold 32 is the tooth profile member in a state where the tooth profile member 12 is fixed. The tooth profile member 12 may be released from the first mold 32 by moving relative to the first mold 32.

  In the mold release step, the tooth profile member 12 is released from the first mold 32 while being deformed toward the space 62 inside the main body 16 over the entire circumference of the main body 16. The mold may be released from the first mold 32 while being deformed in order from one portion in the circumferential direction toward the inner space 62 side.

  The gear 10 is configured as a worm wheel as an example, but may be configured as a gear other than the worm wheel.

  Moreover, although the tooth-shaped member 12 is formed of resin as an example, it may be formed of a material other than resin such as metal. Similarly, the support member 14 is also formed of a resin as an example of a “filler” filled inside the main body 16, but may be formed of a material other than a resin such as a metal, for example.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.

  In the gear 70 according to the second embodiment of the present invention shown in FIG. 7, the structure of the tooth profile member 12 is changed as follows with respect to the gear 10 according to the first embodiment described above. That is, as shown in FIGS. 7 and 8, in the second embodiment of the present invention, the body portion 16 of the tooth profile member 12 is a frame shape having a C shape having a separation portion 72 in a part of the circumferential direction. Is formed.

  In the second embodiment of the present invention, the tooth profile member 12 is manufactured through the same processes as the molding process and the mold opening process in the first embodiment described above. However, in the mold release step, the tooth profile member 12 is released from the first mold 32 as follows.

  FIG. 9 shows how the tooth profile member 12 is released from the first mold 32 in the mold release step of the second embodiment. In FIG. 9, the fixed die 38 and the movable die 40 (see FIGS. 5 and 6) of the second die 34 are not shown. The first die 32 is provided with a plurality of rod-like push pins 76 instead of the cylindrical push pins 76 (see FIGS. 5 and 6) in the first embodiment. The plurality of push pins 76 are arranged in the circumferential direction of the main body portion 16.

  And in the mold release process of 2nd embodiment, the some extrusion pin 76 is raised in order from the extrusion pin 76 located in the one end part of the circumferential direction of the main-body part 16. As shown in FIG. As a result, the tooth profile member 12 is released from the first mold 32 while being deformed in order from one end portion in the circumferential direction of the main body portion 16 to the other end portion in the space 62 side inside the main body portion 16.

  In addition, the tooth-shaped member 12 formed to have the C-shaped main body portion 16 in this way is integrally provided with the support member 14 shown in FIG. 7 in the same secondary molding process as that of the first embodiment. The gear member 70 of the second embodiment is formed by the tooth profile member 12 and the support member 14.

  Thus, according to 2nd embodiment, since the main-body part 16 is formed in C shape, in a mold release process, it can be made to mold release easily, changing the tooth profile member 12 helically.

  Moreover, since the support member 14 is integrally formed inside the main body portion 16 of the tooth profile member 12, the tooth profile member 12 formed in a C shape can be supported by the support member 14 from the inside thereof. Thereby, the rigidity of the tooth profile member 12 can be ensured.

  In addition, when the main body portion 16 is formed in a C shape as in the second embodiment, the main body portion is compared with the case where the main body portion 16 is formed in an annular shape as in the first embodiment. The degree of freedom in designing the shape of the 16 inner peripheral portions can be increased. Thereby, for example, as shown in FIG. 10, the inner peripheral portion of the main body portion 16 is, for example, formed into a shape with high strength or a shape with high holding strength with the support member 14 that is a secondary molded product. can do. In the second embodiment, as an example, the above-described protruding portion 24 (see FIG. 4) is omitted from the tooth profile member 12.

  In the second embodiment described above, when the gear 70 is a worm wheel, it is desirable that the separation portion 72 formed on the C-shaped main body portion 16 is formed with a size that allows the worm to get over. .

  Further, the separation portion 72 is filled with a part of the filler filled inside the main body portion 16 in the secondary molding step, so that both end portions in the circumferential direction of the main body portion 16 as shown in FIG. The connection part 78 which connects may be formed.

  Thus, when the connection part 78 which connects the both ends of the circumferential direction of the main-body part 16 is formed, the deformation | transformation of the main-body part 16 formed in C-shape can be suppressed, and the rigidity of the tooth profile member 12 is ensured. Can do.

  In the second embodiment described above, the undercut portions 20 are formed on the tooth tips of the plurality of teeth 18 and the tooth bottom surfaces between the plurality of teeth 18, respectively. It may be formed only on either one of the tooth tip and the tooth bottom surface between the plurality of teeth 18.

  The gear 70 includes the support member 14. However, the support member 14 may be omitted when the rigidity of the tooth profile member 12 can be ensured in a completely solidified state, for example.

  In the mold release process, it is desirable that the tooth profile member 12 is released from the first mold 32 in a semi-solid state before the tooth profile member 12 is completely solidified. When the deformation of the member 12 is easy, the tooth profile member 12 may be released while the tooth profile member 12 is completely solidified.

  Further, in the mold release step, the tooth profile member 12 is released from the first mold 32 by being pushed by the push pin 76. However, the first mold 32 is the tooth profile member in a state where the tooth profile member 12 is fixed. The tooth profile member 12 may be released from the first mold 32 by moving relative to the first mold 32.

  The gear 70 is configured as a worm wheel as an example, but may be configured as a gear 10 other than the worm wheel.

  Moreover, in 2nd embodiment, although the tooth-shaped member 12 is formed with resin as an example, for example, you may form with materials other than resin, such as a metal. Similarly, the support member 14 is also formed of a resin as an example of a filler that fills the inside of the main body 16, but may be formed of a material other than a resin such as metal, for example.

  The first and second embodiments of the present invention have been described above. However, the present invention is not limited to the above, and various modifications can be made without departing from the spirit of the present invention. Of course there is.

DESCRIPTION OF SYMBOLS 10,70 ... Gear, 12 ... Tooth profile member, 14 ... Support member, 16 ... Body part, 18 ... Teeth, 20 ... Undercut part, 30 ... Mold, 32 ... First mold, 34 ... Second mold, 38 ... fixed type, 40 ... movable type, 62 ... space inside the main body (relief space), 72 ... separation part, 78 ... connection part

Claims (9)

A frame-shaped main body portion having a ring shape or a C-shape having a separation part in a circumferential direction, and a plurality of teeth formed on the outer peripheral portion of the main body portion and arranged in the circumferential direction of the main body portion Each of the tooth tips of the plurality of teeth, a tooth bottom surface between the plurality of teeth, and a tooth surface between the tooth tip and the tooth bottom surface of the plurality of teeth, and the diameter of the main body portion. A molding step having a plurality of undercut portions recessed toward the inside in the direction and forming a tooth profile member constituting the gear using a mold;
Among the molds, the inner periphery of the main body portion is attached to the outer peripheral portion of the main body portion while the first die for forming the outer peripheral portion of the main body portion including the plurality of teeth and the plurality of undercut portions is attached. A mold opening step for separating a second mold for molding a part from the tooth profile member and securing a space inside the main body part;
A mold release step of releasing the first profile from the first mold while deforming the tooth profile member toward the space inside the main body;
A method of manufacturing a gear comprising: In the molding step, the main body is formed in an annular shape,
In the mold release step, the tooth profile member is released from the first mold while the tooth profile member is deformed to the inner space side of the main body section over the entire circumference of the main body section.
The gear manufacturing method according to claim 1. In the molding step, the main body is formed in a C shape,
In the mold release step, the tooth profile member is released from the first mold while the tooth profile member is sequentially deformed from one circumferential end portion to the other end portion of the main body portion toward the inner space of the main body portion. Let
The gear manufacturing method according to claim 1. After the mold release step, further comprising a secondary molding step of filling a filler inside the main body and forming a support member integrally with the tooth profile member by the filler.
The manufacturing method of the gear as described in any one of Claims 1-3. In the molding step, the main body is formed in a C shape,
In the secondary molding step, a part of the filler is filled into the separation part, and a connecting part is formed by connecting a part of the filler in the circumferential direction with the part of the filler.
The manufacturing method of the gearwheel of Claim 4. A frame-shaped main body portion having a ring shape or a C-shape having a separation part in a circumferential direction, and a plurality of teeth formed on the outer peripheral portion of the main body portion and arranged in the circumferential direction of the main body portion Each of the tooth tips of the plurality of teeth, a tooth bottom surface between the plurality of teeth, and a tooth surface between the tooth tip and the tooth bottom surface of the plurality of teeth, and the diameter of the main body portion. A molding surface for molding the outer peripheral portion of the main body portion including the plurality of teeth and the plurality of undercut portions among the tooth-shaped members constituting the gear. A first mold having,
A second mold having a molding surface for molding the inner periphery of the main body,
Mold with. A frame-shaped main body part having an annular shape or a C-shape having a separating part in the circumferential direction;
A plurality of teeth formed on the outer periphery of the main body and arranged in the circumferential direction of the main body;
Each of the tooth tips of the plurality of teeth, a tooth bottom surface between the plurality of teeth, and a tooth surface between the tooth tip and the tooth bottom surface of the plurality of teeth, respectively, and the radial direction of the main body portion A plurality of undercut portions recessed toward the inside;
Gear with. A tooth profile member having the body portion, the plurality of teeth, and the plurality of undercut portions;
A support member formed integrally with the tooth profile member by a filler filled inside the main body,
The gear according to claim 7. The main body is formed in a C shape,
A part of the filler is formed by filling the separation part, and further includes a connection part that connects both ends in the circumferential direction of the main body part,
The gear according to claim 8.