JPH0210307B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structure for preventing wear of a shift fork in a shift operating device for a manual transmission.

First, the gear shift operation device targeted by this invention is
A first forkshaft and a second forkshaft are horizontally mounted on the transmission case so that they can be moved in the axial direction while being prevented from rotating and are parallel to each other. A shift fork is disposed so as to be movable and rotatable in the axial direction, and the shift fork is provided with engaging portions arranged in a direction perpendicular to the fork shaft, and the shift and select lever shaft is disposed in the case. The lever shaft is horizontally mounted so as to be movable and rotatable in the axial direction perpendicular to the forkshaft, and this lever shaft is held in a neutral position via an elastic member. providing a first locking portion that can selectively engage with any of the engaging portions of each of the shift forks;
Further, a first shift head having an engaging part aligned with the engaging part of the shift fork is fixed to the first forkshaft, and the first locking part is fixed to the lever shaft. a second locking portion that can be engaged with the engaging portion of the first shift head only when engaging with any of the engaging portions of the upper shift fork, and further provided on the second fork shaft. fixes a single shift fork and also fixes a second shift head having an engaging part aligned with the engaging part, and selectively attaches the first engaging part of the lever shaft to the engaging part of the shift head. It is configured so that it can be engaged. According to this, the shift fork, which is disposed on the first forkshaft so as to be movable and rotatable in the axial direction, prevents the forkshaft from rotating by engaging with the sleeve of the clutch mechanism for shifting. Therefore, it is more reasonable than the alternative method of spline-fitting the shift fork to the fork shaft to prevent the shift fork from rotating. That is,
Another method of spline-fitting the shift fork to the fork shaft to prevent the shift fork from rotating has problems with machining accuracy, tends to cause backlash, and increases friction at the fitted part, resulting in poor shift feeling. The problem is that the shift fork is rotatably inserted into the fork shaft, and the shift fork is engaged with the sleeve of the clutch mechanism, thereby preventing the shift fork from rotating. This device is rational because it can eliminate the above problems. However, in this device,
Similarly to the first fork, the repulsive force of the elastic member that occurs when the shift and select lever shaft is selected and shifted against the elasticity of the elastic member for holding the shaft in the neutral position is well known. When placed on the shift fork on the shaft, the repulsive force causes the shift fork to rotate on the first fork shaft, and the shift fork comes into pressure contact with the sleeve of the clutch mechanism, and the rotation of the sleeve causes the shift fork to rotate on the first fork shaft. There was a problem in that abnormal wear occurred at the circumferential contact portion of the sleeve.

Therefore, the object of the present invention is to press the shift fork against the sleeve of the clutch mechanism of the gear shift by the repulsive force of the elastic member during the selection operation of the shift and select lever shaft. It is an object of the present invention to provide a wear prevention structure for a shift fork that can prevent abnormal wear of the shift fork.

In order to achieve the above object, the present invention provides a first fork shaft that is prevented from rotating so that the repulsive force of the elastic member during the selection operation of the shift and select lever shaft is not applied to the shift fork. The second locking portion of the lever shaft is configured to lock the first shift head which is fixed.

An embodiment of the present invention will be described below with reference to the drawings. First, an outline of the manual transmission with 5 forward speeds and 1 reverse speed, which is the subject of this example, will be described using the skeleton diagram shown in Figure 1.Input shaft 2 and output shaft 3 are connected to each other in case 1 of the transmission. They are arranged so as to be parallel to each other and to be rotatable. A first gear 4, a reverse gear 5, and a second gear 6 are respectively fixed to the input shaft 2 from the right side in the figure, and a third gear 7, a fourth gear 8, and a fifth gear 9 are each rotatably disposed. The output shaft 3 is rotatably provided with counter gears 10 and 11 that are in constant mesh with the first gear 4 and second gear 6, respectively, and counter gears 12 to 14 that are in constant mesh with the third gear 7 to fifth gear 9, respectively, are fixed. There is.
The counter first gear 10 and the counter second gear 11 are connected to the output shaft 3 by connecting the sleeve 15a of the first clutch mechanism 15.
Third gear 7 and fourth gear 8 rotate integrally with input shaft 2 through connection of sleeve 16a of second clutch mechanism 16, and fifth gear 9 rotates integrally with input shaft 2 through connection of sleeve 16a of second clutch mechanism 16. Through the connection of the sleeve 17a, the input shaft 2 rotates integrally with the input shaft 2, and the rotation of the input shaft 2, which is driven by an engine (not shown) via a clutch, is transmitted to the output shaft 3 at a variable speed. .
A counter reverse gear 18 is provided on the outer periphery of the sleeve 15a of the first clutch mechanism 15, while
A reverse idler gear 20 is provided on a reverse idler shaft 19 rotatably installed in the case 1 so as to be integrally rotatable and movable in the axial direction. By simultaneously meshing the idler gear 20 with the reverse gear 5 and the counter reverse gear 18, the rotation of the input shaft 2 is transmitted to the output shaft 3 in a reverse state. The rotation of output shaft 3 is
The signal is transmitted to the differential device 22 by the drive gear 21 of the shaft 3, and then to the left and right drive shafts 23, 24. In addition,
FIG. 1 shows a state in which the rotation of the input shaft 2 is not transmitted to the output shaft 3, that is,
Indicates the neutral state of the transmission.

Next, a speed change operation device for performing a speed change operation by moving the sleeves 15a to 17a of each of the clutch mechanisms 15 to 17 described above will be described with reference to FIGS. 2 to 5.
As shown in FIGS. 2 and 3, shift forks 25 and 26 are provided on the sleeve 15a of the first clutch mechanism 15 and the sleeve 16a of the second clutch mechanism 16, respectively.
6a and the same sleeves 15a, 16.
engaged so as to be able to move a in the axial direction;
The first shift fork 25 and the second shift fork 26 are connected to the first fork shaft 27.
axially movable and rotatable. This fork shaft 27 is installed in the case 1 so as to be movable in the axial direction in parallel with the input shaft 2. The left end of the forkshaft 27 in FIG. 2 has a width across flats 28, and is prevented from rotating by a retainer 29 attached to the intermediate wall 1a of the case 1.
Also, the sleeve 17a of the third clutch mechanism 17
The third shift fork 30 is attached to the same sleeve 17.
The shift fork 30 is fixed to a second fork shaft 31. The shift fork 30 is engaged with the shift fork 30 to allow rotation of the sleeve 17a and to move the sleeve 17a in the axial direction. This forkshaft 31 is installed in the case 1 so as to penetrate through the intermediate wall 1a thereof and to be movable in the axial direction. This forkshaft 31 is located above and in front of the first forkshaft 27 (upper left in FIG. 3) and is parallel to the first forkshaft 27. Also, both forkshafts 27,3
A reverse shift arm 32 is provided at the right end portion of 1 so as to be movable in the axial direction. The shift arm 32 is connected to the reverse idler gear 20 so as to allow the gear 20 to rotate and to move the gear 20 in its axial direction. This shift arm 32 is connected to the second fork shaft 3.
The rightward movement is restricted by a locking pin 33 attached to the arm 32, while the arm 32 has a one-way locking pin 32 that can engage with the mutually opposing engagement grooves 34 and 35 of both fork shafts 27 and 31. A pin 36 is installed inside. As a result, when the second forkshaft 31 moves to the left, the shift arm 32
The engagement groove 3 of the first forkshaft 27 in which the one-way pin 36 is in a fixed state when the locking pin 33 moves together with the forkshaft 31
The second forkshaft 31 moves upward from 4.
When the second forkshaft 31 returns, the shift arm 32 can move together with the second forkshaft 31. Note that when the second forkshaft 31 moves to the right and when the first forkshaft 27 moves from side to side, the one-way pin 3
6 engages with the engagement groove of the shaft on the non-moving side, and the reverse shift arm 32 is held in an immovable state.

A first shift head 37 is fixed to the first fork shaft 27 between the first shift fork 25 and the second shift fork 26, and a second shift head 37 is fixed to the second fork shaft 31.
8 is located and fixed behind the first shift head 37. The second shift fork 26 has a head portion 26a located behind the second shift head 38, and the first shift fork 25 has a head portion 26a located behind the head portion 26a of the second shift fork 26. 25a is formed. As shown in FIG. 4, engaging grooves A to A are formed in both shift heads 37, 38 and both head portions 25a, 26a, respectively. In the neutral state, the engaging grooves A to A are lined up in a series in a direction perpendicular to the forkshaft.

In the case 1, a shift and select lever shaft 39 is connected to the fork shafts 27, 31.
It is horizontally suspended above the shafts 27, 31 so as to be movable in the axial direction and rotatable in the axial direction. This lever shaft 39 is moved in the axial direction via a remote mechanism by a select operation of a shift lever (not shown), and is rotated via the remote mechanism by a shift operation of the same shift lever. A large diameter portion 40 is formed in the center of the lever shaft 39, and a first inner lever 41 and a second inner lever are formed on the front side of this large diameter portion 40.
The inner levers 42 are fixed in line. At both ends of the lever shaft 39, there are front and rear washers 43,
44 is fitted so as to be movable in the axial direction, and front and rear return springs 45, 46 are provided between the front washer 43 and the second inner lever 42 and between the rear washer 44 and the large diameter portion 40, respectively. is interposed. These washers 43 and 44 are attached to the lever shaft 39.
Front and rear snap springs 47, 48 attached to
While the washers 43 and 44 are in contact with the front and rear walls 1b and 1c of the case 1, the lever shaft 39 is held in a neutral position. A first locking protrusion B projects downward from the first inner lever 44, and this protrusion B engages with the engagement groove A of the second shift fork 26 when the lever shaft 39 is in the neutral position. (See Figure 4 A). Further, the second inner lever 41 has a second locking protrusion C protruding downward, and this protrusion C is connected to the first shift head 3.
7, the first inner lever 4
1 is engaged with each engagement groove A of the first shift fork 25 or the second shift fork 26 (see FIG. 4A and FIG. 4B). When the first inner lever 41 is shifted (rotated) while being engaged with the second shift head 38, as shown in FIG. The rear end surface 42a of the second inner lever 42 is engaged with the front end surface 37a of the first shift head 37, so that the repulsive force thereof does not apply rotational force to the second shift fork 26. Further, an interlock plate 49 is attached to the lever shaft 39 so as to cover the first inner lever 41 and to allow rotation of the lever shaft 39. A groove 50 is formed on the upper surface of the interlock plate 49 along the axial direction of the lever shaft 39, and the tip 52 of the lock bolt 51 screwed into the upper part of the case 1 is engaged with the groove 50. and the interlock plate 49 is prevented from rotating. As shown in FIG. 4, front and rear locking protrusions 53 and 54 are formed at the lower end of the interlock plate 49, with the locking protrusion B of the first inner lever 41 interposed therebetween. These locking protrusions 53 and 54 are connected to both inner levers 4.
Engagement groove A in which the locking protrusions B and C of 1 and 42 do not engage
~A can be engaged with. That is,
When the lever shaft 39 is in the neutral position, the locking protrusions 53 and 54 are in the second position as shown in FIG.
shift head 38 and first shift fork 25
is held immovably, and the first inner lever 41
When the lever engages the first shift fork 25, the second shift fork 26 and the second shift head 38 are held immovably, and the first inner lever 41 When engaged with the shift head 38, the first shift head 37, first shift fork 25, and second shift fork 26 are held immovably, as shown in FIG. 4C. Further, the lever shaft 39 has a large diameter portion 4 of the shaft 39.
The ball 56 of the temporary fixing mechanism 55 attached to the interlock plate 49 is biased by the spring 57.
By engaging one of the three locking grooves 49a to 49c on the inner circumference, it is held at the selected rotational position (see FIG. 5).

In the above-mentioned speed change operation device, when obtaining the first speed, the shift and select lever shaft 39 in the neutral state is moved backward (right side in Figure 3).
By moving against the elasticity of the heli return spring 46 and performing a selection operation, the locking protrusion B of the first inner lever 41 becomes engaged with the engagement groove A of the first shift fork 25. ,
When the lever shaft 39 is rotated counterclockwise in FIG. 2 and a shift operation is performed, the first shift fork 25 is moved to the right, and the sleeve 15a of the first clutch mechanism 15 is moved to the counterclockwise direction. It is connected to the first gear 10. Thus, the second shift head 37 is inserted into the engagement groove A of the first shift head 37.
Since the shift operation is performed with the locking protrusion C of the inner lever 42 engaged, the lever shaft 3
9, the first shift fork 25 and the first
and the forkshaft 27 will move together. At this time, the second shift fork 26 and the second shift head 38 become immovable due to the engagement of the engagement grooves A, A with the engagement protrusions 53 of the interlock plate 49, and the second The shift fork 26 moves relatively on the first fork shaft 27.

To obtain the second speed, by shifting the lever shaft 39 in the opposite direction to the rotating direction of the lever shaft 39 in the case of the first speed, the first shift fork 25 is moved to the left, and the sleeve 15 is moved to the left.
a is connected to the counter second gear 11. In this case as well, the first shift fork 25 moves integrally with the first fork shaft 27, as in the case of the first speed.

To obtain third speed, the shift and select lever shaft 39 in the neutral state is rotated counterclockwise in FIG. 2 to perform a shift operation, so that the locking projection B of the first inner lever 41 is engaged. 2nd shift fork 2
6 is moved to the right, and the sleeve 16a of the second clutch mechanism 16 is connected to the third gear 7. Therefore, since a shift operation is performed with the locking protrusion C of the second inner lever 42 engaged with the engagement groove A of the first shift head 37, the second shift fork is rotated as the lever shaft 39 rotates. 26 and the first forkshaft 27 move together. At this time, the first shift fork 25 and the second shift head 38 become immovable due to the engagement of the engagement grooves A, A with the engagement protrusions 53, 54 of the interlock plate 49, and the second shift head 38 becomes immovable. The first shift fork 25 moves relatively on the first fork shaft 27.

To obtain the fourth speed, by shifting the lever shaft 39 in the opposite direction to the rotating direction of the lever shaft 39 in the case of the third speed, the second shift fork 26 is moved to the left, and the sleeve 16
a is connected to the force gear 8. In this case too,
As in the case of third gear, the second shift fork 2
6 moves integrally with the first forkshaft 27.

To obtain the fifth gear, the shift and select lever shaft 39 in the neutral state is moved forward against the elasticity of the return spring 45 to perform the select operation.
The locking protrusion B of the inner lever 41 is engaged with the engagement groove A of the second shift head 38,
In addition, when the lever shaft 39 is rotated counterclockwise in FIG. 2 and a shift operation is performed, the third shift fork 30 is moved to the right together with the second fork shaft 31, and the third shift fork 30 is moved to the right. The sleeve 17a of the mechanism 17 is the fifth gear 9
connected to. Therefore, the first shift head 3
7. The first shift fork 25 and the second shift fork 26 become immobile due to the engagement of the engagement grooves 53 and 54 of the interlock plate 49 with their engagement grooves A to A, and The first forkshaft 27 is stationary with the shift head 37
Since the one-way pin 36 is engaged with the engagement groove 34, the reverse shift arm 32 is also immovable. In this state, the return spring 4
The repulsive force No. 5 is received by the second inner lever 42 being locked to the first shift head 37, and therefore, the repulsive force generated in the conventional shift fork 26 is different from that in the conventional shift fork 26. Abnormal wear of the shift fork 26 in the circumferential direction due to pressure contact of the clutch mechanism 16 with the sleeve 16a can be prevented.

Note that in order to change from each of the forward states to the neutral state, the above operations may be performed in the reverse order.

When reversing, the lever shaft 39 is shifted in the opposite direction to the rotation direction of the lever shaft 39 in the case of the fifth speed, and the second fork shaft 31 is moved to the left, and the reverse shift arm 32 is moved together with the shaft 31 by the locking pin 33, and the reverse idler gear 20 is moved between the reverse gear 5 and the counter reverse gear 1.
Can be engaged with 8 at the same time. Even in this state, abnormal wear of the shift fork 26 in the circumferential direction is prevented in the same manner as in the case of the fifth speed.
Furthermore, when returning from reverse to neutral, the one-way pin 36 engages with the engagement groove 35 of the second forkshaft 31 during the shift to reverse, so the reverse shift arm 32 moves together with the second forkshaft 31. It returns to a neutral state.

That is, the present invention provides a first shift head fixed on a first forkshaft which is prevented from rotating, and a second shift and select lever shaft.
Since the locking part of the lever shaft is locked, the repulsive force of the elastic member is not applied to the shift fork when the lever shaft is selected, and this prevents the abnormal wear in the circumferential direction of the shift fork that conventionally occurs. can be prevented.

[Brief explanation of drawings]

The drawings show one embodiment of the invention.
The figure is a skeleton diagram of a manual transmission, Figure 2 is a front sectional view of the gear shift operating device, Figure 3 is a sectional view of the same side, Figure 4 is an enlarged view of the connecting part of the lever shaft and fork shaft, and A is a neutral Condition, b is 1.2
C shows the selected state to the speed side, and C shows the selected state to the 5th speed/reverse side, respectively, and FIG. 5 is a sectional view taken along the line -- in FIG. 3. DESCRIPTION OF SYMBOLS 1... Case, 25... First shift fork, 26... Second shift fork, 27... First fork shaft, 37... First shift head, 39... Shift and select lever shaft, 41 ...First inner lever, 42...Second inner lever, 45...Return spring (elastic member), A...Engagement groove (engagement part), B...First locking protrusion (first (locking part), C... second locking protrusion (second locking part).

Claims (1)

[Claims] 1. A first forkshaft and a second forkshaft are horizontally mounted in a case of a transmission so that they can be moved in the axial direction while being prevented from rotating, and are parallel to each other, and the first forkshaft has a plurality of forkshafts. A shift fork is disposed to be movable and rotatable in the axial direction, the shift fork is provided with engaging portions arranged in a direction perpendicular to the fork shaft, and the case is provided with a shift and select lever shaft. The lever shaft is horizontally mounted so as to be movable and rotatable in the axial direction in a state perpendicular to the forkshaft, and this lever shaft is held in a neutral position via an elastic member, and the lever shaft has a mechanism for axial movement of the shaft. A first locking portion that can selectively engage with any of the engaging portions of each shift fork is provided, and the first fork shaft has a first locking portion that is aligned with the engaging portion of the shift fork. 1st with part
A shift head is fixed to the lever shaft, and the first shift head is engaged with the lever shaft only when the first locking part engages with any engagement part of the shift fork on the first fork shaft. a second locking part that can be engaged with the second fork shaft; further, a single shift fork is fixed to the second fork shaft, and a second shift head having an engaging part aligned with the engaging part is provided. and the first lever shaft of the lever shaft is fixed to the engaging portion of the shift head.
In the speed change operating device configured such that the first locking portion can be selectively engaged, the lever shaft is moved in the axial direction against the elasticity of the elastic member, so that the first locking portion is engaged with the first locking portion. When the lever shaft is rotated in this state, the second locking portion is locked to the first shift head, and the lever is moved by the repulsive force of the elastic member. A wear prevention structure for a shift fork, characterized in that the shift fork is configured to prevent movement of the shaft in the axial direction.