JP2016070371A - Shift fork of manual transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shift fork of a manual transmission which can enhance rigidity while extremely avoiding enlargement as a whole, and is excellent in wear resistance and lubrication performance.SOLUTION: As a plurality of pad parts 31, 32 which are arranged at a substantially semi-circular recessed edge 33 of a shift fork main body part 3, there are used a pair of first pad parts 31 which are located in vicinities of both ends of the recessed edge 33, and the second pad part 32 which is located between the pair of first pad parts 31. Ribs 34 protruding to an axial length direction of a sleeve 1 are formed at portions adjacent to the second pad part 32, and when lubrication oil which is scattered in a transmission abuts on the ribs 34, the oil can flow to a side face 32a of the second pad part 32, and the second pad part 32 is set smaller than the pair of first pad parts 31 in a width in the axial length direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a shift fork of a manual transmission used for moving a shift sleeve in a manual transmission of a vehicle such as an automobile.

The present applicant has previously proposed the one described in Patent Document 1 as an example of a shift fork of a manual transmission.
The shift fork described in this document includes a shift fork main body having a concave edge curved in a substantially semicircular arc shape. The shift fork main body portion is provided so as to be movable in the axial direction of the sleeve after the concave edge portion is set in a state of entering the outer peripheral groove of the sleeve for speed change. Three pad portions are provided on the concave edge portion. These three pad portions are portions in which the width (width in the axial direction of the sleeve) is made larger than the other portions of the concave edge portion.
Such a shift fork can push the shift sleeve in the axial direction thereof, and the movement of the sleeve switches on / off the transmission of the driving force to the shift gear.

  However, the prior art still has room for improvement as described below.

First, the shift fork receives a reaction force when moving the sleeve. For this reason, sufficient strength is required. Further, the rigidity of the shift fork also affects the feeling when the driver of the vehicle performs a shift operation, and it is desired to increase the strength (rigidity) of the shift fork in order to improve the feeling. However, an increase in the size and weight of the shift fork should be avoided as much as possible.
Secondly, the sleeve rotates during shifting operation while the vehicle is running, and in order to bring the shift fork into contact with the rotating sleeve, the contact portion requires high wear resistance and lubricity. The

Japanese Patent Laid-Open No. 11-118029

  The present invention has been conceived under the circumstances as described above, and can increase the strength while avoiding the enlargement of the whole as much as possible, and is excellent in wear resistance and lubricity. The problem is to provide a shift fork for a manual transmission.

  In order to solve the above problems, the present invention takes the following technical means.

A shift fork of a manual transmission provided by the present invention has a substantially semicircular arc-shaped concave edge portion, and the axial length of the sleeve is such that the concave edge portion enters an outer peripheral groove of a speed change sleeve. A shift fork main body portion provided movably in a direction, and a plurality of pad portions provided at the concave edge portion and having a width in the axial length direction larger than other portions of the concave edge portion, A pair of first pad portions positioned near both ends of the concave edge portion, and a second pad portion positioned between the pair of first pad portions, as the plurality of pad portions. A shift fork of a manual transmission, wherein a portion of the shift fork main body adjacent to the second pad is provided with a rib projecting in the axial length direction, and Lubrication splashing in the machine When the oil hits the rib, the oil can flow to the side surface of the second pad portion, and the second pad portion is formed by each of the pair of first pad portions. Is characterized in that the width in the axial direction is reduced.

According to such a configuration, the following effects can be obtained.
(1) The rib provided adjacent to the second pad portion reinforces the shift fork main body portion. For this reason, the strength of the shift fork can be increased, and a feeling of rigidity can be generated during the shift operation to improve the shift operation feeling. The rib does not need to be formed so large, and it is possible to appropriately suppress an increase in size and weight of the entire shift fork.
(2) Inside the manual transmission, there is a state where the lubricating oil is scraped up and scattered by various gears and the like, and when such oil hits the rib, the oil is transmitted along the rib. Flowing to the side surface of the second pad portion. On the other hand, since the width of the second pad portion is smaller than that of the first pad portion, the gap between the side surface of the second pad portion and the inner side surface of the outer peripheral groove of the sleeve is large. Therefore, the oil that has flowed to the side surface of the second pad portion through the ribs can easily enter the gap, and a large amount of oil can be actively introduced into the outer peripheral groove of the sleeve. As a result, the lubricity of the contact portion between the shift fork and the sleeve can be improved and the wear resistance can be improved.
(3) Since the width of the pair of first pad portions is wider than the width of the second pad portion, the width of the gap between the side surface of the first pad portion and the side surface of the outer peripheral groove of the sleeve is reduced. As a result, the oil that has flowed into the outer circumferential groove of the sleeve from the position of the second pad portion is less likely to flow out from the position of the first pad portion, and an effect of confining the oil in the outer circumferential groove is also obtained. For this reason, the lubricity of the contact part of a shift fork and a sleeve can be made more favorable.
(4) As described above, when the lubricity of the contact portion between the shift fork and the sleeve is improved, the feeling of the shift operation can be further improved based on the rotational resistance reducing action. In addition, the fuel efficiency of the vehicle can be improved.
(5) About a pair of 1st pad parts, the width | variety of a sleeve is larger than a 2nd pad part, and it is located in the both ends vicinity of a concave edge part. For this reason, the pair of pad portions are brought into contact with each other in an arrangement that is not biased with respect to the sleeve (an arrangement state in which the pair of pad portions are opposed to each other across the center of the sleeve), and the sleeve is balanced It is possible to push appropriately. The second pad portion can be provided with a function of preventing the shift fork from falling over. That is, according to the present invention, among the three pad portions, the second pad portion located at the center promotes oil inflow and functions as a pad portion for preventing the shift fork from falling down. About a pair of 1st pad part located in the side, it is functioning as a pad part for pushing a sleeve with sufficient balance, and the structure is rational.

  Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings.

(A) is principal part sectional drawing which shows an example of the use condition of the shift fork of the manual transmission which concerns on this invention, (b) is the outer periphery groove | channel of a shift fork and the 1st among the structures shown to (a). It is a principal part expanded sectional view of the fitting part with 2 pad parts, (c) is the essential part of the fitting part of the outer periphery groove | channel of a shift fork and the 1st pad part among the structures shown to (a). FIG. (A) is a side view of the shift fork shown in FIG. 1, (b) is IIb-IIb sectional drawing of (a).

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  As shown in FIG. 1 (a), the shift fork A of the present embodiment is for moving the shift sleeve 1 of the manual transmission in the axial length direction, and this point is conventionally known. It is the same. In the structure shown in FIG. 1, speed change gears Ga and Gb are rotatably fitted on the horizontal rotary shaft 20 via bearings 21a and 21b, and between the gears Ga and Gb. The clutch hub 22 fitted to the spline portion 20a of the rotary shaft 20 and the speed change sleeve 1 constituting the synchronizer are provided on the outer peripheral portion thereof. When the sleeve 1 is pushed in the left-right direction in FIG. 1 by the shift fork A, one of the gears Ga and Gb can be selectively connected to the rotary shaft 20.

  As shown in FIG. 2, the shift fork A includes a shift fork main body 3 in which a concave edge 33 curved in a substantially semicircular arc shape is formed. A cylindrical boss 30 is provided at a position near the base of the shift fork main body 3, and a fork shaft 40 is fitted into the boss 30 and connected using a pin 41.

  The concave edge portion 33 is provided with a pair of first pad portions 31 and one second pad portion 32. The pair of first pad portions 31 is provided in the vicinity of both end portions of the concave edge portion 33, and the second pad portion 32 is provided at an intermediate position between the pair of first pad portions 31. Each of the first and second pad portions 31 and 32 is a portion in which the width in the axial length direction of the sleeve 1 is made larger than the other portions of the concave edge portion 33. However, the widths La and Lb of the first and second pad portions 31 and 32 are not the same, and the width Lb of the second pad portion 32 is made smaller than the width La of the first pad portion 31. Yes.

  A rib 34 protruding in the axial length direction of the sleeve 1 is integrally formed on a portion of the shift fork main body 3 adjacent to the second pad portion 32 such as the upper side or the diagonally upper side of the second pad portion 32. Yes. Preferably, the rib 34 is provided on each of the left and right side surfaces of the shift fork main body 3. As shown in FIG. 2B, the rib 34 is provided so as to connect the outer peripheral side flange 35 of the shift fork main body 3 and the upper part of the second pad portion 32. The second pad portion 32 is connected to the side surface 32a. As a result, as will be described later, when the lubricating oil scattered in the manual transmission hits the ribs 34, the oil can smoothly flow to the side surface 32a of the second pad portion 32. Yes.

  Next, the operation of the shift fork A will be described.

  First, as shown in FIG. 1A, the shift fork A is set in a state in which the concave edge portion 33 is fitted in the outer peripheral groove 10 of the sleeve 1, and in the axial length direction of the sleeve 1 corresponding to the shift operation. The sleeve 1 is pushed by being moved. At this time, the sleeve 1 receives a reaction force, but the shift fork A is provided with a pair of ribs 34, and the strength thereof is increased. It can be given. Further, since the rigidity of the shift fork A is increased due to the presence of the ribs 34, the feeling during the shift operation is also improved. The ribs 34 may be relatively small in size, and can appropriately suppress an increase in the size and weight of the shift fork A as a whole.

Inside the manual transmission, the lubricating oil is scraped and scattered by various rotating members and the like, and a part of such oil hits the ribs 34. Then, this oil flows to the side surface 32 a of the second pad portion 32. Here, the second pad portion 32
Since the width Lb of the second pad portion 32 is small, the width Ld of the gap Cb between the side surface 32a of the second pad portion 32 and the inner side surface of the outer peripheral groove 10 of the sleeve 1 is slightly larger, as shown in FIG. It will be a thing. Therefore, the oil that has flowed to the side surface 32a of the second pad portion 32 can easily enter the gap Cb, and a large amount of oil can be actively introduced into the outer circumferential groove 10. On the other hand, as shown in FIG. 1C, the width Lc of the gap Ca between the side surface 31a of the first pad portion 31 and the inner side surface of the outer peripheral groove 10 of the sleeve 1 is very small. For this reason, it is suppressed that the oil which flowed in in the outer periphery groove | channel 10 flows out outside from the clearance gap Ca. For this reason, the lubricity of the contact portion between the shift fork A and the sleeve 1 is improved, and the wear resistance is excellent.

  As described above, since the thickness of the second pad portion 32 is smaller than that of the pair of first pad portions 31, the pushing operation of the sleeve 1 is mainly performed by the pair of first pad portions 31. This is performed in contact with the side surface of the outer peripheral groove 10. The second sleeve 1 plays a role in preventing the shift fork A from falling over. Here, since the pair of first pad portions 31 are disposed so as to face each other with the central axis of the sleeve 1 interposed therebetween, the sleeve 1 can be pushed in a well-balanced state with no bias. For example, unlike the present embodiment, when the first pad portion having a large width is provided at only one location, the pressing location of the sleeve 1 is one location, and it is difficult to appropriately push the sleeve 1 in a balanced manner. It becomes. Further, if all of the three pad portions have a small width, the rattling of the shift fork A increases, which is not preferable. The shift fork A of the present embodiment can preferably avoid such problems.

  The present invention is not limited to the contents of the above-described embodiment. The specific configuration of each part of the shift fork of the manual transmission according to the present invention can be modified in various ways within the intended scope of the present invention.

The ribs are preferably provided on both side surfaces of the shift fork main body, but may be provided only on one side surface. In addition, a plurality of ribs may be provided on both side surfaces of the shift fork main body so that the number of the ribs is slightly larger so that the strength of the shift fork main body is further increased. The specific shape and size of the ribs are not limited. In short, when lubricating oil splashed in the transmission hits the ribs, the oil can flow to the side surface of the second pad portion. What is necessary is just to be provided adjacent to the 2nd pad part.
The 1st and 2nd pad part should just have the relationship of the positional relationship and width dimension which this invention intends. The shift fork main body only needs to be configured as a portion having a substantially semicircular arc-shaped concave edge that enters the outer peripheral groove of the gearshift sleeve, and the specific shape, size, material, and the like are not limited.

A Shift fork 1 Sleeve 10 Outer groove (sleeve)
3 Shift fork main body 31 First pad 31a Side surface (of first pad)
32 2nd pad part 32a Side surface (of 2nd pad part)
33 concave edge 34 rib

Claims (1)

A shift fork main body having a substantially semicircular arc-shaped concave edge, and being provided to be movable in the axial length direction of the sleeve so that the concave edge enters the outer peripheral groove of the sleeve for speed change;
A plurality of pad portions provided at the concave edge portion and having a width in the axial length direction larger than other portions of the concave edge portion;
With
The plurality of pad portions include a pair of first pad portions located in the vicinity of both end portions of the concave edge portion, and a second pad portion located between the pair of first pad portions. A shift fork of a manual transmission,
Of the shift fork main body portion, a portion adjacent to the second pad portion is provided with a rib projecting in the axial length direction, and when lubricating oil scattered in the transmission hits the rib, This oil can flow to the side surface of the second pad portion,
The shift fork of a manual transmission, wherein the second pad portion has a smaller width in the axial length direction than each of the pair of first pad portions.

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