Multi-stage helical gear manufacturing apparatus and multi-stage helical gear manufacturing method

Patent metadata

Field	Value
Publication number	US-12496758-B2
Application number	US-202318385438-A
Country	US
Kind code	B2
Filing date	Oct 31, 2023
Priority date	Nov 8, 2022
Publication date	Dec 16, 2025
Grant date	Dec 16, 2025

Abstract

A multi-stage helical gear manufacturing apparatus includes a first mold member, a second mold member, a large gear rotation core, a sleeve pin, a small gear rotation insert, and an insert pin. The second mold member moves the insert pin and the small gear rotation insert after the insert pin is caused to retreat in relation to the small gear rotation insert at the time of mold opening. The first mold member prohibits rotation of the large gear rotation core at the time of mold clamping, permits rotation of the large gear rotation core when the insert pin and the small gear rotation insert of the second mold member are moved at the time of mold opening, and causes the sleeve pin to advance toward the second mold member in relation to the plastic after the insert pin and the small gear rotation insert are separated from the plastic.

First claim

What is claimed is:

1 . A multi-stage helical gear manufacturing apparatus for manufacturing a multi-stage helical gear including a first gear and a second gear arranged on a same axis, wherein
the multi-stage helical gear includes a center hole extending along a center line of the first gear and the second gear, a linear spline extending along the center line is formed on an inner circumferential surface of the center hole, first helical teeth are formed on an outer circumferential surface of the first gear, and second helical teeth are formed on an outer circumferential surface of the second gear, the second helical teeth having an inclination different from that of the first helical teeth of the first gear, the multi-stage helical gear manufacturing apparatus comprises:
a first mold member and a second mold member, the multi-stage helical gear manufacturing apparatus being configured to inject a plastic into a cavity between the first mold member and the second mold member when the first mold member and the second mold member are clamped, and then remove the multi-stage helical gear formed of the plastic when the first mold member and the second mold member are opened;
a first gear rotation core for forming the first gear and the first helical teeth, the first gear rotation core being rotatably supported by the first mold member;
a sleeve pin for forming the center hole and the spline, the sleeve pin being supported by the first mold member so as to advance and retreat in directions approaching and separating from the second mold member;
a second gear rotation insert for forming the second gear and the second helical teeth, the second gear rotation insert being rotatably supported by the second mold member; and
an insert pin inserted into the second gear rotation insert, the insert pin being supported by the second mold member so as to advance and retreat in directions approaching and separating from the first mold member in relation to the second gear rotation insert,
the cavity is formed between the first mold member and the second mold member by the first gear rotation core, the sleeve pin, the second gear rotation insert, and the insert pin at a time of mold clamping, when advancing in relation to the second gear rotation insert at the time of mold clamping, the insert pin prohibits the second gear rotation insert from rotating relative to the second mold member, when retreating in relation to the second gear rotation insert at a time of mold opening, the insert pin permits the second gear rotation insert to rotate relative to the second mold member, the second mold member is configured to move the insert pin and the small second gear rotation insert away from the first mold member after the insert pin is caused to retreat in relation to the second gear rotation insert at the time of mold opening, and the first mold member is configured to
prohibit rotation of the first gear rotation core at the time of mold clamping,
permit rotation of the first gear rotation core when the insert pin and the small second gear rotation insert of the second mold member are moved away from the first mold member at the time of mold opening, and
cause the sleeve pin to advance toward the second mold member in relation to the plastic after the movement of the insert pin and the second gear rotation insert away from the plastic.

2 . The multi-stage helical gear manufacturing apparatus according to claim 1 , wherein
the first mold member is provided with a first plate and a second plate arranged in this order in a direction away from the second mold member, the first plate rotatably supports the first gear rotation core, the second plate
prohibits rotation of the first gear rotating core when contacting the first plate, and
permits rotation of the first gear rotation core when separated from the first plate,
the second mold member is provided with a third plate, a fourth plate, and a fifth plate arranged in this order in a direction away from the first mold member, the third plate rotatably supports the second gear rotation insert, the fourth plate supports the insert pin, the fifth plate is provided with a runner and a gate for injecting the plastic into the cavity, a spring load N 1 acts between the third plate and the fourth plate in the second mold member, a spring load N 2 acts between the fourth plate and the fifth plate in the second mold member, the first plate, the second plate, the third plate, the fourth plate, and the fifth plate come into contact with each other when the first mold member and the second mold member are clamped, the first mold member and the second mold member are provided with:
a first lock mechanism capable of locking and releasing the first plate and the second plate; and
a second lock mechanism capable of locking and releasing the first plate and the third plate, and
the first lock mechanism, the second lock mechanism, the spring load N 1 , and the spring load N 2 are set such that, when the first mold member and the second mold member are opened, the first plate, the second plate, the third plate, the fourth plate, and the fifth plate are moved to cause separations between the plates to occur in an order of a separation of the fourth plate and the fifth plate from the third plate, a separation of the fifth plate from the fourth plate, a separation of the third plate, the fourth plate, and the fifth plate from the first plate, and a separation of the second plate from the first plate.

3 . The multi-stage helical gear manufacturing apparatus according to claim 1 , wherein
the insert pin protrudes into the cavity and comes into contact with the sleeve pin when the first mold member and the second mold member are clamped, and the insert pin forms the center hole and the spline of the multi-stage helical gear at a portion protruding into the cavity.

4 . The multi-stage helical gear manufacturing apparatus according to claim 1 , wherein
the insert pin includes a protrusion on an outer circumferential surface, the protrusion protruding in a radial direction, an inner circumferential surface of the second gear rotation insert into which the insert pin is inserted is provided with an accommodation groove that accommodates the protrusion when the insert pin is inserted, the accommodation groove includes a helical wall and a vertical wall and is wider than the protrusion of the insert pin, the helical wall extends helically along an inner circumferential surface of the second gear rotation insert and comes into contact with the protrusion of the insert pin when the insert pin is inserted into the second gear rotation insert, and when the insert pin is inserted deep into the second gear rotation insert, the vertical wall comes into contact with the protrusion together with the helical wall to prohibit rotation of the second gear rotation insert relative to the second mold member.

5 . A multi-stage helical gear manufacturing method for manufacturing a multi-stage helical gear including a first gear and a second gear arranged on a same axis, wherein
the multi-stage helical gear includes a center hole extending along a center line of the first gear and the second gear, a linear spline extending along the center line is formed on an inner circumferential surface of the center hole, first helical teeth are formed on an outer circumferential surface of the first gear, second helical teeth are formed on an outer circumferential surface of the second gear, the second helical teeth having an inclination different from that of the first helical teeth of the first gear, the multi-stage helical gear manufacturing method comprises:
injecting a plastic into a cavity between a first mold member and a second mold member when the first mold member and th

Assignees

• Toyota Boshoku Kk

Inventors

• Wakimoto Yuki
• Sakaguchi Yuta
• Suenaga Rikiya

Classifications

• B29C45/2681 Primary

  with rotatable mould parts · CPC title

• B29C2045/445

  using the movable undercut forming element for ejection of the moulded article · CPC title

• B29L2015/003

  Gears · CPC title

• B29C45/44 Primary

  for undercut articles · CPC title