Vehicle parking lock device

Inventors: Kunio Morisawa (Toyota, JP); Shigetsugu Iwata (Toyota, JP); Takuya Kodama (Toyota, JP); Takafumi Koshida (Anjo, JP)

Assignee: Toyota Jidosha Kabushiki Kaisha

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Quick Facts

Patent No.: US 8,668,067
App. No.: 13/390,401
Granted: Mar 11, 2014
Kind: B2

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Abstract

A vehicle parking lock device having a parking rod; a tapered parking cam disposed at a leading end portion of the parking rod; and a cam guiding device that guides the parking cam moved together with the parking rod in association with a projection of the parking rod toward the leading end portion to move a parking lock pole with the parking cam to a position of engagement with a parking lock gear rotated together with a transmission output member, the cam guiding device including a first guiding member in a cylindrical shape and a second guiding member in a half cylindrical shape that is disposed subsequently to the first guiding member, the second guiding member having a tapered guiding concave surface that guides the parking cam toward the parking lock pole in association with the projection of the parking rod toward the leading end portion.

Claims (30)

1. A vehicle parking lock device comprising: a parking rod that has a base end portion rotatably coupled to a detent plate, the parking rod being projected toward a leading end portion in association with rotation of the detent plate to a parking position; a tapered parking cam disposed at the leading end portion of the parking rod; and a cam guiding device that guides the parking cam moved together with the parking rod in association with the projection of the parking rod toward the leading end portion to move a parking lock pole rotatably disposed on a transmission case with the parking cam to a position of engagement with a parking lock gear rotated together with a transmission output member,

the parking rod being projected from inside of the transmission case toward an opening portion of the transmission case,

the cam guiding device including a first guiding member in a cylindrical shape that has an inner guiding surface guiding the parking cam, the first guiding member being fitted immovably in a direction orthogonal to a shaft center into a first receiving surface formed into a cylindrical surface shape within the transmission case, a second guiding member in a half cylindrical shape that is disposed subsequently to the first guiding member such that the second guiding member is received from a position on the side opposite to the parking lock pole by a second receiving surface formed adjacently in a shaft center direction to the first receiving surface within the transmission case and such that movement toward the parking lock pole is regulated by the first guiding member, the second guiding member having a tapered guiding concave surface that guides the parking cam toward the parking lock pole in association with the projection of the parking rod toward the leading end portion; and a fixing member that is fixed to the opening portion of the transmission case, the fixing member being engaged with an end portion of the second guiding member to regulate the rotation of the second guiding member around the shaft center and the movement toward the opening portion of the transmission case.

2. The vehicle parking lock device of claim 1 , wherein the second guiding member has an inner circumferential surface including the tapered guiding concave surface and an outer circumferential surface that is a cylindrical convex curved surface, and wherein the tapered guiding concave surface has a center line of curvature displaced from a center line of curvature of the outer circumferential surface toward the parking lock pole by a predetermined amount.

3. The vehicle parking lock device of claim 2 , wherein the first receiving surface formed on the transmission case and the second receiving surface formed adjacently in a shaft center direction to the first receiving surface are formed concentrically with each other, and wherein the curvature radius of the second receiving surface is greater than the curvature radius of the first receiving surface.

4. The vehicle parking lock device of claim 3 , wherein

an end portion of the first guiding member closer to the second guiding member has a partially cylindrical portion in a semicircular shape formed to be located closer to the second receiving surface in the end portion with an unchanging curvature radius, and a partially tapered portion formed to be located closer to the parking lock pole in the end portion with a curvature radius increased toward the second guiding member so as to avoid interference between the parking cam guided toward the parking lock pole by the tapered guiding concave surface and the first guiding member, and wherein

an end portion of the inner circumferential surface of the second guiding member closer to the first guiding member is overlapped with the partially cylindrical portion of the first guiding member.

5. The vehicle parking lock device of claim 4 , wherein due to contact of the partially tapered portion of the first guiding member with a circumferential end surface of the second guiding member, relative rotation equal to or greater than a predetermined amount around the shaft center becomes impossible between the first guiding member and the second guiding member.

6. The vehicle parking lock device of claim 2 , wherein

the second guiding member has an engagement protrusion formed on an end surface closer to the fixing member, wherein

the fixing member is a plate material with a cutout into which the engagement protrusion is fitted, and wherein