JP2565671Y2 - Transmission shift fork - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a shift fork used in a vehicle transmission.

2. Description of the Related Art A shift fork used in a transmission, wherein at least a radially inner portion of the shift fork is fitted in a circumferential groove of a coupling sleeve to move the coupling sleeve in an axial direction. A radially inner portion, or at least a part thereof, is fitted into the circumferential groove with a gap, and the sliding claw portion is integrally held at a transition portion at a circumferential end. 2. Description of the Related Art A shift fork is known which includes a bone portion, and an outer support portion which is integrally disposed radially outside the sliding claw portion and the inner bone portion and is wider in the axial direction than these.

Since the coupling sleeve rotates at a high speed integrally with the rotating shaft, it is necessary to constantly supply lubricating oil between the coupling sleeve and the sliding claws of the shift fork. The lubricating oil supplied is, as schematically shown in the diagram of FIG. 5, the lubricating oil introduced into the inner bottom of the transmission case by the rotation of the gears, and is pumped up as shown by the arrow. It is scattered and supplied between the sliding surface 3 of the coupling sleeve 2 and the sliding claw of the shift fork 1.

[Problem to be Solved by the Invention] Since the gap between the sliding claw portion and the sliding surface of the coupling sleeve circumferential groove is extremely small, it is said that lubricating oil is efficiently supplied between them. If the lubricating oil supply is not sufficient, seizure of the sliding parts may occur.

Japanese Utility Model Publication No. 63-2902 discloses one solution to this problem. According to this method shown in FIGS.
The lubricating oil scattered by the gears is supplied from an upward oil supply hole 46 provided at the end 43a of the sliding claw portion 41a on the upstream side in the rotational direction, which is not immersed in the lubricating oil, and the through hole 47 on the side thereof is provided.
It is supplied to the sliding surface more.

Although this method is an effective method for supplying lubricating oil to the sliding surface of the sliding claw portion, as can be easily understood from FIGS. The disadvantage is that the arrangement of the sliding claws of the fork is limited, that is, the upstream sliding claws are arranged so that the oil supply hole faces upward, and the downstream sliding claws must be immersed in lubricating oil. In addition, there is a disadvantage that the number of man-hours for machining increases due to the provision of a lubrication hole and the like.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an improved shift fork in which lubricating oil is sufficiently supplied to the sliding surface of a sliding claw portion and the risk of seizure is eliminated, in view of the above-mentioned problems of the conventional shift fork. It is in.

It is a further object of the present invention to provide an improved shift fork by minimizing secondary machining as much as possible and without increasing the number of machining steps by a simple and inexpensive method.

[Means for Solving the Problems] The object of the present invention is achieved by the following solutions.

The means according to claim 1, wherein at least a radially inner portion of the coupling groove is fitted into the circumferential groove of the coupling sleeve to move the coupling sleeve in the axial direction. At least a part of the radially inner portion is fitted with a gap, and the sliding claw portion is integrally held at its circumferential end, and is more axially than the sliding claw portion in the coupling sleeve. A narrow inner bone portion, and an outer support portion that is integrally disposed radially outside the sliding claw portion and the inner bone portion and is wider in the axial direction than the sliding claw portion, The inner end of the inner bone part, which fits into the circumferential groove, gradually approaches the bottom surface of the circumferential groove as it moves from the inner bone part to the sliding claw part. Shift fork comprising a rib provided with a guide surface for guiding lubricating oil on the bottom surface of a circumferential groove A.

A means according to claim 2, wherein a sliding claw portion at least radially inside of which is fitted in the circumferential groove of the coupling sleeve to move the coupling sleeve in the axial direction, At least a part of the radially inner portion is fitted with a gap, and the sliding claw portion is integrally held at its circumferential end, and is more axially than the sliding claw portion in the coupling sleeve. A narrow inner bone portion, and an outer support portion that is integrally disposed radially outside the sliding claw portion and the inner bone portion and is wider in the axial direction than the sliding claw portion, An inner end portion of the inner bone portion which is fitted into the circumferential groove, a band portion which is protruded toward the inner wall of the circumferential groove, is wide in the axial direction, and is narrower than the sliding claw portion. And a shift fork.

The present invention is based on the following fact that the lubricating oil is not sufficiently supplied to the sliding claws due to the following fact.

That is, as shown in FIG. 6a, which is a view of the tip of the shift fork, the lubricating oil that has scattered and adheres to the inner bone 5 causes the rotational force of the coupling sleeve to be applied to the sliding surface of the sliding claw 4. Alternatively, it is supplied by gravity, but does not enter the circumferential groove of the coupling sleeve, but flows on the surface of the sliding claw portion in the gap between the outer support portion 6 and the peak portion of the coupling sleeve 2. As shown in FIG. 6b, which is a view taken along the line BB in FIG. 6a, the inner bone part 5 is smaller than the sliding claw part 4, as shown in FIG. The width in the axial direction and the size in the direction toward the bottom surface of the circumferential groove of the coupling sleeve 2 are made somewhat smaller, and they are not in direct contact with the circumferential groove of the coupling sleeve 2. The lubricating oil adhering to the portion 5 flows through the gap with the circumferential groove 2,
The focus is on the fact that the coupling sleeve 2 is scattered due to centrifugal force caused by rotation.

According to the invention of claim 1, the inner end fitted into the circumferential groove of the inner bone has a bottom surface of the circumferential groove as it moves from the inner bone to the sliding claw. By providing a rib having a guide surface for guiding the lubricating oil on the bottom surface of the circumferential groove gradually approaching, the lubrication that flows in the gap between the inner bone portion and the bottom surface of the circumferential groove and scatters to the outside. The oil is captured, and the captured lubricating oil flows along the guide surface of the rib and is effectively supplied to the sliding surface of the sliding claw portion.

According to the invention of the second aspect, the inner end portion fitted into the circumferential groove of the inner bone portion projects toward the inner wall of the circumferential groove and is wider in the axial direction than the sliding claw portion. By providing a narrow band (peak), lubricating oil flowing in the gap between the inner bone portion and the bottom of the circumferential groove and scattered outside the groove is reduced, and therefore lubricating oil trapped in the circumferential groove is reduced. The oil increases, and the lubricating oil is effectively supplied to the sliding surface of the sliding claw portion.

[Example] An example of a shift fork according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a shift fork according to an embodiment of the present invention, taken along a direction perpendicular to a rotation shaft and a shift fork shaft, together with an engaging coupling sleeve. The shift fork 1 is slidably supported by a shift fork shaft 9 and engages with the coupling sleeve 2 through fitting of the sliding claw 4 with the circumferential groove. The shift fork 1 has a sliding claw 4
An outer rib 8 formed at a connection portion (transition portion) with the inner rib, an inner rib 7 formed on both side surfaces near an inner peripheral end of the inner bone portion,
The outer shape is a fan-shaped outer support portion 6 and a semicircular concave portion at the inner bone portion.

FIG. 2 is a detailed view of the vicinity of the sliding claw portion 4 of the shift fork for showing the details of the outer rib 8 and the inner rib 7.
In the figure, the sliding claw portion 4 is formed to be somewhat wider in the axial direction than the inner bone portion 5 and to protrude somewhat from the inner bone portion 5 toward the bottom surface of the circumferential groove of the coupling sleeve 2. I have. The outer supporting portion 6 is arranged integrally with the outer side of the sliding claw portion 4 and the inner bone portion 5, and is formed to be considerably wider in the axial direction than these. The sliding claw portion 4 has machined both side surfaces and an inner surface serving as sliding surfaces with the coupling sleeve circumferential groove, and the inner bone portion 5 is directly in contact with the coupling sleeve engaging groove. Therefore, it has a molded surface like the outer support portion 6 except for a transition portion with the sliding claw portion.

In a side wall portion of the inner bone portion 5 adjacent to the outer support portion 6, a transition portion from the inner bone portion 5 to the sliding claw portion 4 includes an outer rib 8
Is provided. The side surface 8a of the outer rib 8 is finished almost flat with the side surface of the sliding claw portion 4. The width of the side surface 8a of the outer rib 8 is increased with the transition from the inner bone portion 5 to the sliding claw portion 4, and the surface width of the side surface 8a finally becomes the surface of the side surface of the sliding claw portion 4. When the width is almost half, the side surface 8a of the outer rib 8 shifts to the side surface of the sliding claw portion 4.

Also, there is a step between the side surface 8a of the outer rib 8 and the side surface 7a of the inner rib 7, and this step is
It gradually becomes smaller as it moves to, and finally disappears. As this step surface moves from the inner bone portion 5 to the sliding claw portion 4, it gradually approaches the bottom surface of the circumferential groove of the coupling sleeve 2 and guides the lubricating oil to the bottom surface of the circumferential groove. The guide surface 8b.

An inner rib 7 provided at an inner end portion of the inner bone portion 5 which is fitted into a circumferential groove of the coupling sleeve 2 includes a side surface 7a on a plane substantially orthogonal to the axial direction of the coupling sleeve 2, And a guide surface 7b which is a vertical surface along the axial direction of the coupling sleeve 2. Side of this inner rib
7 a disappears in contact with the side surface of the sliding claw portion 4. Guide surface 7b
Gradually approaches the bottom surface of the circumferential groove of the coupling sleeve 2 as it moves from the inner bone portion 5 to the sliding claw portion 4,
In addition, the lubricating oil is guided to the bottom of the circumferential groove.

Further, the inner bone portion 5 has a vertical surface 5b parallel to the axial direction of the coupling sleeve 2 and a side surface 5a orthogonal to the vertical surface 5b (on a plane orthogonal to the axial direction of the coupling sleeve 2). Have.

Although not shown in FIG. 2, the side surface 5a,
7a, 8a and guide surfaces 7b, 8b are similarly provided on the side symmetrical with respect to the vertical surface 5b.

In the shift fork 1 formed in this manner, as shown in FIG. 6A, the lubricating oil which is captured by the outer support portion 6 and the inner bone portion 5 and drips from the inner bone portion surface or scatters by rotation. Is supplied to the sliding surface which is caught by the outer rib 8 and slides on the bottom surface of the circumferential groove of the coupling sleeve 2 of the sliding claw portion 4, and as shown in FIG. The lubricating oil that scatters due to centrifugal force due to the rotation of the coupling sleeve 2 through the gap between the end face of the inner bone 5 and the bottom of the circumferential groove of the coupling sleeve 2 is removed.
And is supplied to the sliding surface of the sliding claw portion 4 through the inner rib 7. The lubricating oil is caught by the outer ribs 8 and the inner ribs 7 particularly on the sliding claws on the downstream side in the rotational direction (the side where the coupling sleeve rotates from the inner bone toward the tip of the sliding claws). In this case, the sliding claw 4 of the shift fork is mounted upward (the tip of the sliding claw 4 is upward (empty)) in the direction of gravity or downward (the tip of the sliding claw 4 is directed downward (ground)). ) Is effective regardless of whether it is mounted on the guide surface (guide surfaces 7b, 8b
As a result, the lubricating oil that tends to scatter in the rotational direction by receiving the rotational force in the tangential direction along the circumferential direction of the coupling sleeve 2 is captured and guided toward the bottom surface of the circumferential groove).

In the sliding claw 4 on the upstream side in the rotation direction (the side on which the coupling sleeve 2 rotates from the tip of the sliding claw 4 toward the inner bone 5), the sliding claw 4 of the shift fork is When mounted downwards in the direction of gravity,
Particularly, the lubricating oil is effectively captured (the lubricating oil falling by gravity while receiving a rotational force in a tangential direction along the circumferential direction of the coupling sleeve 2 is captured by the guide surfaces 7b and 8b, and Guided towards the bottom of the circumferential groove).

FIGS. 3 and 4 are partial detailed views showing the structure of the shift fork of the embodiment according to the second aspect of the present invention. FIG. 3 shows an example in which an axially wide band (ridge) 7 ′ is provided at the inner end of the inner bone 5 fitted into the circumferential groove of the coupling sleeve 2. In this case, too, the flow of the oil shown in FIG. In this case, it has been confirmed that the action of trapping the lubricating oil works more effectively by reducing the gap between the end face of the inner bone portion and the bottom face of the circumferential groove.

FIG. 4 shows a combination of an outer rib 8 provided at the transition of the inner bone 5 to the sliding claw 4 shown in FIG. 2 and a crest 7 'of the inner bone shown in FIG. FIG. 6 is a view showing a shift fork according to an embodiment of the present invention.

[Effects of the Invention] In the invention according to claim 1, the inner end fitted into the circumferential groove of the inner bone has a bottom surface of the circumferential groove as the inner bone moves to the sliding claw. And a rib provided with a guide surface for guiding the lubricating oil on the bottom surface of the circumferential groove, thereby catching the lubricating oil scattered by the centrifugal force from the circumferential groove of the coupling sleeve. Then, the captured lubricating oil can be supplied to the sliding claw portion by the guide surface. Also, since the ribs can be formed on the inner bone without precision machining, sufficient lubricating oil can be supplied to the sliding surface of the sliding claw without increasing the number of steps due to secondary processing. It became possible to supply shift forks.

In the invention according to claim 2, the inner end portion fitted into the circumferential groove of the inner bone portion has an axially wide width that protrudes toward the inner wall of the circumferential groove and is wider than the sliding claw portion. The narrow band prevents the flow of the lubricating oil in the circumferential groove of the coupling sleeve, improves the effect of trapping the lubricating oil, and makes it possible to effectively supply the lubricating oil to the sliding claws. . Also,
The belt can be formed on the inner bone without precision machining, so it is possible to provide sufficient lubricating oil to the sliding surface of the sliding claw without increasing the number of steps due to secondary processing etc. It is now possible to provide a shift fork.

[Brief description of the drawings]

FIG. 1 is a sectional view of a shift fork according to an embodiment of the present invention, together with a coupling sleeve, taken along a direction perpendicular to a rotation axis. FIG. 2 is a slide fork of the shift fork of FIG. FIG. 3 is an explanatory view of a figure near the moving claw part, and FIG. 3 is a sectional view of an inner bone part and a circumferential groove in a rotation axis direction showing a structure of a shift fork according to an embodiment of the present invention. FIG. 4 is a perspective view showing the structure of a shift fork according to another embodiment of the present invention according to the second aspect of the present invention, and FIG. 5 is a view common to the conventional and present shift forks.
The shift fork is straightened for easy understanding in a side view parallel to the axis of rotation of the coupling sleeve, showing the state of lubricating oil supply to the engagement between the circumferential groove of the coupling sleeve and the shift fork. 6a and 6b are views showing the state of flow of the lubricating oil of the conventional shift fork discovered in the present invention, and FIG. 7a and FIG. Fig. 1 is a cross-sectional view of a conventional shift fork that supplies lubricating oil, taken in a direction perpendicular to the axis, schematically showing the flow of lubricating oil, and Fig. B is a view showing the structure of the sliding claw portion. (Description of Signs) 1; Shift Fork 2; Coupling Sleeve 3; Sliding Surface, 4; Sliding Claw 5; Inner Bone, 6; Outer Support 7; Inner Rib, 7 '; 8) Outer rib

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Keita Matsuura 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) References JP-A-55-76256 (JP, A) JP-A-61-27369 (JP, A) Japanese Utility Model Showa 54-82878 (JP, U) Japanese Utility Model Showa 57-84030 (JP, U) Japanese Utility Model Showa 56-113921 (JP, U) Japanese Utility Model Showa 57-97729 (JP, U) JP-A-61-190064 (JP, U) JP-A-63-170661 (JP, U) JP-A-1-140066 (JP, U) JP-A-61-204052 (JP, U) JP-A 1-132857 (JP, U) JP, U) Jiko 63-2902 (JP, Y2)

Claims (2)

(57) [Scope of request for utility model registration] At least a radially inner portion of the coupling sleeve is fitted into a circumferential groove of the coupling sleeve to move the coupling sleeve in the axial direction. At least a part of the inner portion is fitted with a gap, and the sliding claw portion is integrally held at its circumferential end, and is narrower in the axial direction of the coupling sleeve than the sliding claw portion. An inner supporting portion, an outer supporting portion integrally disposed radially outside the sliding claw portion and the inner bone portion, and having a width greater in the axial direction than the sliding claw portion; The inner end of the bone fitted into the circumferential groove gradually approaches the bottom surface of the circumferential groove as the inner bone moves from the inner bone to the sliding claw. A shift fork comprising a rib having a guide surface for guiding lubricating oil on a bottom surface of the shift fork. 2. A sliding claw portion for moving the coupling sleeve in the axial direction by fitting at least a radially inner portion of the coupling sleeve into a circumferential groove of the coupling sleeve; At least a part of the inner portion is fitted with a gap, and the sliding claw portion is integrally held at its circumferential end, and is narrower in the axial direction of the coupling sleeve than the sliding claw portion. An inner supporting portion, an outer supporting portion integrally disposed radially outside the sliding claw portion and the inner bone portion, and having a width greater in the axial direction than the sliding claw portion; At the inner end of the bone fitted into the circumferential groove, the width is axially wide, protruding toward the inner wall of the circumferential groove,
A shift fork having a band narrower than the sliding claw.