JPH11247975A - Shift fork lubrication structure - Google Patents

Abstract

(57) [Summary] [Object] In a lubrication structure for a shift fork, it is possible to favorably perform lubrication between a shift fork and a synchronization sleeve, and also to prevent heat generation. A shift fork is provided with a chevron oil groove whose top portion is directed in the rotation direction of the synchronization sleeve.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lubrication structure for a shift fork, and more particularly to a lubrication structure for a shift fork that lubricates between a shift fork provided on a shift shaft and a synchronization sleeve of a synchronization mechanism.

[0002]

2. Description of the Related Art A vehicle is provided with a transmission in order to convert the driving force of an engine to a required one according to a traveling condition and to extract the required driving force. Such transmissions include manual, gear-type transmissions.

In a manual gear-type transmission, a main shaft as a rotating shaft and a counter shaft are arranged in parallel in a transmission case, and a plurality of stages of main gears are provided on the main shaft, and the counter shaft is provided on the counter shaft. A plurality of speed counter gears meshed with each speed main gear are provided to form a plurality of speed change gear trains, and a synchronizing mechanism for selectively meshing one of the plurality of speed change gear trains is provided. A shift fork that engages with the synchronization sleeve is provided on a shift shaft that is axially moved, and a shift fork that moves axially integrally with the shift shaft and a synchronization sleeve that rotates integrally with the rotation shaft are provided between the shift fork and the synchronization sleeve. Lubrication is performed.
In the case of such lubrication, the sleeve for synchronization, each speed gear, etc., scoops up the lubricating oil that has accumulated in the lower portion of the transmission case, and this lubricating oil is forcibly dropped by an oil collecting unit, an oil gutter, or the like. ing.

A lubricating structure for such a shift fork is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-217726.
This is disclosed in Japanese Utility Model Laid-Open No. 6-62929. Japanese Unexamined Patent Publication No. Hei 7-217726 discloses an oil supply groove extending in the circumferential direction of a synchronization sleeve provided on a claw portion formed on a shift fork, thereby providing a space between the shift fork and the synchronization sleeve. Lubrication is performed. Japanese Unexamined Utility Model Publication No. Hei 6-65629 discloses a guide step surface for guiding lubricating oil on the upper surface of a shift fork to an axial edge portion, and the axial step edge portion of the guide step surface is used as a synchronization mechanism. By requesting upward, the lubrication performance of the synchronization mechanism is improved.

[0005]

However, in the conventional lubricating structure for a shift fork, in order to perform lubrication between the shift fork and the synchronization sleeve, an oil collecting portion, an oil gutter, and the like are required. Since it is necessary to provide ribs, oil holes, oil receiving parts, etc. that support oil gutters, it is necessary to significantly change the layout, which complicates the configuration, increases the cost, and increases compatibility. There was a disadvantage that it could not be retained.

Further, the lubrication performance between the shift fork and the synchronization sleeve is poor, and the synchronization load becomes relatively large.
Fuel economy and engine output are low, heat generation is large, and oil deterioration and burn-in occur.

[0007]

Therefore, in order to eliminate the above-mentioned disadvantages, the present invention provides a transmission case in which a main shaft as a rotating shaft and a counter shaft are arranged in parallel, and a plurality of stages are provided on the main shaft. Each speed main gear is provided, and a plurality of speed counter gears meshed with each speed main gear are provided on the counter shaft to form a plurality of speed gear trains, and one of the plurality of speed gear trains is selected. And a shift fork engaged with a synchronization sleeve of the synchronization mechanism is provided on a shift shaft that is axially moved, and the shift fork and the rotation are integrally moved with the shift shaft in the axial direction. In a lubrication structure for a shift fork for performing lubrication between a shaft and a synchronous sleeve that rotates integrally, a top portion of the shift fork has the synchronous thread. Characterized in that a chevron oil groove directed in the rotational direction of the probe.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the present invention, between a shift fork and a synchronizing sleeve, lubricating oil is guided to a chevron oil groove with rotation of the synchronizing sleeve, and this lubricating oil is conveyed to the chevron oil. It is guided smoothly to the top of the groove, which reduces friction between the shift fork and the synchronization sleeve to improve fuel economy and engine output, and reduces heat generation to prevent oil deterioration and seizure. In addition, since only the chevron oil groove is provided in the shift fork, it is not necessary to change the entire structure and the compatibility can be maintained.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; 1 to 5 show a first embodiment of the present invention. In FIG. 5, reference numeral 2 denotes a manual transmission connected to the vehicle engine, a gear transmission, 4 a clutch, 6 a transmission case, 8
Is a front case wall, 10 is a rear case wall, 12 is an intermediate case, and 14 is an extension case.

In the transmission case 6, an input shaft 16 for inputting a driving force from an engine, and a main shaft 18 serving as a rotating shaft connectable to and detachable from the input shaft 16 are provided.
And a counter shaft 20 and a reverse idler shaft 22 which are arranged substantially parallel to the main shaft 18 are supported.

The input shaft 16 is connected to a crankshaft (not shown) on the engine side and is supported by an input shaft bearing 24 held on the front case wall 8. The input shaft 16 is provided with an input side directly-coupled gear 26.

The main shaft 18 is supported by a first main shaft bearing 28 held by the rear case wall 10 and a second main shaft bearing 30 held by the extension case 14.

The counter shaft 20 is connected to the front case wall 8.
, A second counter shaft bearing 34 held by the rear case wall 10, and a third counter shaft bearing 36 held by the extension case 14.

The reverse idler shaft 22 is supported by the rear case wall 10 and the intermediate case 12.

The main shaft 18 includes a first speed main gear 38 and a second speed main gear 40 as a plurality of speed main gears.
, A third speed main gear 42, a fifth speed main gear 44, and a reverse main gear 46 are rotatably provided, and a propulsion shaft (not shown) is attached to a rear end side.

The counter shaft 20 includes a counter-side directly-coupled gear 48 meshing with the input-side directly-coupled gear 26, a first-speed counter gear 50 meshing with the first-speed main gear 38, and a second-speed main gear as a plurality of speed counter gears. 2 meshing with 40
A speed counter gear 52, a third speed counter gear 54 meshing with the third speed main gear 42, a fifth speed counter gear 56 meshing with the fifth speed main gear 44, and a reverse counter gear 58 meshing with the reverse main gear 46 are fixedly provided. Have been.

A reverse idler gear 60 meshing with the reverse counter gear 58 is fixedly provided on the reverse idler shaft 22.

As a result, in the transmission 2, an input gear train 62 composed of the input-side directly connected gear 26 and the counter-side directly connected gear 48 is provided as a plurality of speed gear trains.
A first-speed gear train 64 composed of a first-speed main gear 38 and a first-speed counter gear 50, a second-speed gear train 66 composed of a second-speed main gear 40 and a second-speed counter gear 52, and a third-speed main gear 42 and a third-speed counter gear 54. Third gear train 68 consisting of
And a fifth-speed gear train 70 composed of a fifth-speed main gear 44 and a fifth-speed counter gear 56, and a reverse gear train 72 composed of a reverse main gear 46, a reverse counter gear 58, and a reverse idler gear 60.

First speed main gear 38 and second speed main gear 40
In the intermediate main shaft 18, a first-speed / second-speed synchronization mechanism 76-1 having a first-speed / second-speed synchronization sleeve 74-1 is provided. The 1-speed / 2-speed synchronization sleeve 74-1 has
The first / second speed fork 80-1 attached to the first / second speed shift shaft 78-1 is engaged with the first / second speed fork engaging groove 74.
-1a.

Third speed main gear 42 and main side input gear 2
In the main shaft 18 between the six gears, a third-speed / fourth-speed synchronization mechanism 76-2 having a third-speed / fourth-speed synchronization sleeve 74-2 is provided. The 3-speed / 4-speed synchronous sleeve 74-2 has
The 3rd / 4th shift fork 80-2 attached to the 3rd / 4th shift shaft 78-2 is engaged with the 3rd / 4th speed fork engaging groove 74.
-2a.

On the main shaft 18 between the fifth speed main gear 44 and the reverse main gear 46, a fifth speed / reverse synchronization mechanism 7 having a fifth speed / reverse synchronization sleeve 74-3 is provided.
6-3 are provided. A 5-speed / reverse shift fork 80-3 attached to a 5-speed / reverse shift shaft 78-3 is mounted on the 5-speed / reverse synchronization sleeve 74-3.
It is provided in engagement with the engagement groove 74-3a for the reverse fork.

A shift and select lever 82 is selectively engaged with the first speed / second speed shift shaft 78-1, the third speed / fourth speed shift shaft 78-2, and the fifth speed / reverse shift shaft 78-3. You. The shift-and-select lever 82 is fixed to a shift-and-select shaft 84, and the first-speed / second-speed shift shaft 78-
The first and third speed / fourth shift shaft 78-2 and the fifth speed / reverse shift shaft 78-3 are selectively engaged with each other.
High speed / second speed shift shaft 78-1 and third speed / fourth speed shift shaft 78-
The second and fifth speed / reverse shift shafts 78-3 are selectively moved in the axial direction.

Shift fork 80 and synchronization sleeve 74
The shift fork 80 is provided with a chevron oil groove 86 so as to lubricate a sliding portion (engaging portion) between them.

In the first embodiment, the shift fork 80 is made of sheet metal, and as shown in FIGS. 1 and 2, a boss portion 90 having a shift shaft hole 88 into which the shift shaft 78 is inserted is formed. An arc-shaped arm portion 92 is provided continuously with the boss portion 90.

That is, the one-side sliding surface portions 94a, 94a and the other-side sliding surface portions 94a at both end portions of the arm portion 92 are provided.
On one side, b and 94b are formed one-side angled oil groove 86a and the other-side angled oil groove 86b. The one-side chevron oil groove 86a and the other-side chevron oil groove 86b each have a top portion C
Are directed in the direction of rotation of the sleeve 74 for synchronization, that is, both directions are the first in the direction of rotation of the sleeve 74 for synchronization.
Further, a plurality (for example, three) are formed in a group.

Next, the operation of the first embodiment will be described.

When the engine is driven and the main shaft 18 rotates in the direction shown in FIGS. 1 and 4, the synchronization sleeve 74 also rotates integrally with the main shaft 18, and as shown in FIG. When the oil flows into the chevron oil groove 86, the lubricating oil flows in the direction of the top portion C of the chevron oil groove 86 to reach the sliding portion, and the gap between each sliding surface portion 94 of the shift fork 80 and the synchronization sleeve 74. Lubricate.

As a result, the friction between the shift fork 80 and the sleeve 74 for synchronization can be reduced, so that the synchronization load can be reduced to improve fuel economy and engine output, and also to improve shift feeling.

Further, heat generation by the shift fork 80 and the synchronization sleeve 74 can be reduced, deterioration of the lubricating oil (oil deterioration) can be prevented, wear can be reduced, and the occurrence of seizure can be prevented.

Further, since a plurality of (for example, three) angled oil grooves 86 are formed in a group, the amount of lubricating oil can be properly secured, and the lubricating performance can be further improved.

Further, since only the angled oil groove 86 is formed in the sliding surface 94 of the arm portion 92 of the shift fork 80, other components are not required, and the layout does not need to be changed, and compatibility is maintained. It can be inexpensive.

FIGS. 6 and 7 show a second embodiment of the present invention.

The features of the second embodiment are as follows. That is, the shift fork 102 is made of an aluminum material, and is provided with a boss 108 having a shift shaft hole 104 and a pin hole 106 formed in a direction perpendicular to the shift shaft hole 104, and is connected to the boss 108. Arm part 1
It consists of 10. Each one-side sliding surface portion 112a and each other-side sliding surface portion 112b at both ends of the arm portion 110 include:
A plurality of (for example, three) one-side and other-side chevron oil grooves 114a and 114b, each of which has the top portion C directed in the rotation direction of the synchronization sleeve 74, are formed in groups.

According to the structure of the second embodiment, the same effects as those of the first embodiment can be obtained, and the angled oil groove 114 can be easily provided even when the shift fork 102 is made of aluminum.

[0035]

As is apparent from the above description, according to the present invention, the shift fork is provided with a chevron-shaped oil groove whose top portion is directed in the rotation direction of the synchronization sleeve. It reduces fuel friction and engine output by reducing friction with the sleeve, and reduces heat generation to prevent oil deterioration and seizure.
Since only the chevron oil groove is provided in the shift fork, it is not necessary to change the whole, and the compatibility can be maintained.

[Brief description of the drawings]

FIG. 1 is a front view of a shift fork.

FIG. 2 is a side view of the shift fork of FIG. 1;

FIG. 3 is a diagram illustrating a flow of a lubricating oil.

FIG. 4 is a sectional view of a transmission.

FIG. 5 is another cross-sectional view of the transmission.

FIG. 6 is a front view of a shift fork according to a second embodiment.

FIG. 7 is a side view of the shift fork of FIG. 6;

[Explanation of symbols]

 2 Transmission 6 Transmission case 16 Input shaft 18 Main shaft 20 Counter shaft 62 Input gear train 64 First gear train 66 Second gear train 68 Third gear train 70 Fifth gear train 72 Reverse gear train 74 Synchronization sleeve 76 Synchronization mechanism 78 Shift shaft 80 shift fork 86 angled oil groove

Claims (2)

[Claims] A transmission case has a main shaft as a rotating shaft and a counter shaft arranged in parallel, a plurality of speed main gears provided on the main shaft, and the counter shaft meshed with the respective speed main gears. A plurality of speed counter gears are provided to form a plurality of speed change gear trains, a synchronizing mechanism for selectively meshing one of the plurality of speed change gear trains is provided, and a synchronizing sleeve of the synchronizing mechanism is engaged. A shift fork is provided on a shift shaft that is axially moved, and lubrication is performed between the shift fork that moves axially integrally with the shift shaft and the synchronization sleeve that rotates integrally with the rotary shaft. A shift fork lubricating structure, wherein the shift fork is provided with a chevron oil groove whose top portion is oriented in the rotation direction of the synchronization sleeve. Fork lubrication structure. 2. The shift fork lubrication structure according to claim 1, wherein a plurality of the angled oil grooves are provided in a group on a sliding surface portion of the shift fork.