JPH0747646Y2 - Gear change operation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a speed change operation device, and is intended to facilitate the operation thereof.

(Prior Art) As a conventional gear shift operation device, for example, Japanese Patent Application Laid-Open No. 57-13774
Some are disclosed in Japanese Patent Publication No. 8. In this conventional gear shift operation device, a control rod (gear shift operation shaft) is provided in the housing portion for axial movement operation and shaft center rotation operation, and each shift lever is selected by rotating the control rod. By operating the control rod in the axial direction, the shift fork and the coupling sleeve of the shifting synchromesh mechanism can be moved via the shift lever to shift the gears from the first speed to the fifth speed.

Further, the control rod is formed with three notches adjacent to each other in the axial direction, and a shift check ball (positioning ball) biased in a direction to engage with the notches.
This makes it possible to obtain a sense of moderation during a shift operation.

(Problems to be solved by the invention) However, in the above-mentioned conventional technique, when the control rod is axially moved to select the first to fifth speeds, the control rod is axially moved and operated. No control mechanism is provided on the control rod itself, and such control is indirectly controlled by other parts, such as the abutment of the shift arm and the shift lever. It could get worse.

Then, as a comparative example of the gear shift operating device different from the above-mentioned conventional technique, one shown in FIG. 10 can be considered. The gear shift operating device according to this comparative example includes a gear shift operating shaft 58 that is radially inward of the holding bracket 59 and is axially movable with respect to the holding bracket 59 and rotatable about the shaft.
A rotation bracket 62 which is located radially outward of 59 and whose axial movement is restricted with respect to the holding bracket 59 and which is interlockingly connected via an operation lever so as to rotate in conjunction with the speed change operation shaft 58. A plurality of positioning grooves 69 are arranged in the axial direction in the 58, and positioning balls that can be freely inserted into and removed from the positioning grooves 69.
70 is held by the holding bracket 59, and this positioning ball
A spring 72 that biases the 70 in the direction of fitting into the positioning groove 69 is held by the rotating bracket 62.

According to this comparative example, when the rotating bracket 62 is relatively rotated with respect to the holding bracket 59 by operating the operation lever, the inner peripheral surface of the rotating bracket 62 causes the positioning ball 69 to move from the positioning groove 69 to the positioning ball 69 as shown in FIG. Of the gear shift operation shaft is prevented by the positioning ball 70.
It is possible to prevent the 58 from moving in the axial direction and directly lock the shift operation shaft 58 itself to improve operability.

However, the gear shifting operation shaft 58 and the rotating bracket for shifting
When 62 is rotated, the engagement between the spring 72 and the positioning ball 70 is disengaged as shown in FIG. 11, and even if it is attempted to rotate the speed change operation shaft 58 to the original position again, the spring 72 and the positioning ball 70 Is not easy to re-engage, and there is a problem in that the speed change operation lacks smoothness.

Therefore, according to the present invention, when the operation lever is in the neutral position, the positioning ball that is biased in the direction to be fitted into the positioning groove formed in the gear shift operation shaft is operated by operating the operation lever so that the rotary bracket is held relative to the holding bracket. By holding it by the inner peripheral surface of the rotating bracket so that it does not separate from the positioning groove when it rotates, it is possible to prevent the gear shifting operation shaft from accidentally moving in the axial direction and to smoothly rotate the gear shifting operation shaft and the rotating bracket. The purpose is to achieve

(Means for Solving the Problems) The present invention is characterized in that a cylindrical holding bracket is used.
A gear shifting operation shaft 58 that is inward of the diameter of 59 and is movable in the axial direction with respect to the holding bracket 59 and rotatable about the axis.
A rotary bracket 62, which is located radially outside the holding bracket 59, is restricted from moving axially with respect to the holding bracket 59, and is interlockingly connected via the operation lever 3 so as to rotate in conjunction with the speed change operation shaft 58; Positioning groove 69 on the speed change operation shaft 58
Are arranged side by side in the axial direction, and positioning balls 70 that can be inserted into and removed from the positioning grooves 69 are held in through holes 71 formed in the holding bracket 59.
A spring 72 for biasing in the direction of fitting into 69 is held by the rotating bracket 62, and between the positioning ball 70 and the spring 72,
An auxiliary ball 76 held by the rotating bracket 62 is interposed, and when the rotating bracket 62 rotates relative to the holding bracket 59, the inner peripheral surface of the rotating bracket 62 separates the positioning ball 70 from the positioning groove 69. And the auxiliary ball 76 is configured to make spherical contact with the opening edge of the through hole 71.

(Operation) When the gear shift operation shaft 58 and the rotary bracket 62 are rotated relative to the holding bracket 59 by operating the operation lever 3, the positioning ball 70 is moved by the inner peripheral surface of the rotary bracket 62.
Is held so as not to be separated from the positioning groove 69, and in such a state, the positioning ball 70 prevents the shift operation shaft 58 from accidentally moving in the axial direction. Further, an auxiliary ball 76 interposed between the positioning ball 70 and the spring 72.
However, since the spherical contact is made between the opening edge of the through hole 71 in which the positioning ball 70 is held and the positioning ball 70, the gear shift operation shaft 58
Can be smoothly rotated.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

The drawing relates to a shift operating device for an agricultural tractor to which the present invention is applied. As shown in FIG. 7, a tractor 1 is a vehicle body constructed by connecting a mission case 2, an engine and the like. A gear shift operation lever 3, a steering handle 4, a seat 5 and the like are provided.

Inside the transmission case 2, a transmission 6 shown in FIGS. 3 to 5 is installed.

That is, in the partition wall 27 of the mission case 2, the main shaft 7,
A PTO system transmission shaft 8, a PTO system reverse rotation shaft 9, and a traveling system transmission shaft 10 are supported.

The main shaft 7 is connected to an engine (not shown) via a clutch device 11, and four gears 12, 13,
14, 15 are arranged side by side in the axial direction so that they cannot rotate relative to each other.

The PTO system transmission shaft 8 is located below the main shaft 7, and on the outer periphery thereof,
Four transmission gears 16, 17, 18, and 19 that mesh with the transmission gears 12, 13, 14, and 15 on the outer periphery of the main shaft 7 are loosely fitted on the outer periphery,
Further, the reverse rotation gear 20 is provided so as not to rotate relatively. Further, collars 21 and 22 are fitted onto the outer periphery of the PTO system transmission shaft 8 so that they cannot rotate relative to each other, and the first shift ring 24 of the first shifter 23 and the third shift ring of the third shifter 25 are fitted to the collars 21 and 22. 26 and 26 are externally fitted via a spline so as to be movable in the axial direction and non-rotatable relative to each other.

That is, the first shifter 23 includes a first shift shaft 28 that is axially movably supported by the partition wall 27 of the mission case 2,
A first shift fork 29 fixed to the first shift shaft 28
And the first shift ring 24 which engages with the first shift fork 29 via the outer peripheral groove so as to be relatively slidable. Then, the axial movement of the first shift shaft 28 is transmitted to the first shift ring 24 via the first shift fork 29. As a result, the first shift ring 24 has a power transmission position which is selectively fitted to the collar 21 and the two shift gears 16 and 17 on the left side in FIG. The position can be freely changed to a neutral position shown in the drawing which is not fitted. A circumferential groove 31 is provided on the outer circumference of one end of the first shift shaft 28 in parallel at three positions in the axial direction, and a ball 32 that can be fitted into and removed from each circumferential groove 31.
Is installed in the partition wall 27, and is biased in the fitting direction by the compression spring 33 so that it can be positioned at each power transmission position and neutral position.

Similarly to the first shifter 23, the third shifter 25 also has a third shift shaft 34 axially movably supported by the partition wall 27 of the mission case 2 and a third shift shaft fixed to the third shift shaft 34. It has a fork 35 and the third shift ring 26 which is slidably engaged with the third shift fork 35 via an outer peripheral groove. Then, the axial movement of the third shift shaft 34 is changed by the third shift fork 35 to the third shift ring.
26. As a result, the third shift ring 26
A power transmission position that is selectively fitted to the collar 22 and the two transmission gears 18 and 19 on the right side in FIG. 3 via the splines 36;
The position can be freely changed to the illustrated neutral position in which neither gear is fitted. Further, the third shift shaft 34 is axially positioned in the same configuration as the first shift shaft 28.

As shown in FIG. 4, a first reverse gear 37 and a second reverse gear 38 are fitted around the outer periphery of the PTO reverse rotation shaft 9 so as to freely rotate. The first reverse rotation gear 37 is meshed with one transmission gear 12 on the outer circumference of the main shaft 7, and the second reverse rotation gear 38 is connected to the PT.
It is meshed with a reverse rotation gear 20 on the outer periphery of the O-system transmission shaft 8. A second shift ring 40 of a second shifter 39 is fitted to the first reverse gear 37 and the second reverse gear 38 so as to be axially movable via a spline 43.

That is, the second shifter 39 includes a second shift shaft 41 that is axially movably supported by the partition wall 27 of the mission case 2,
The second shift fork 42 fixed to the second shift shaft 41
And the second shift ring 40 which is slidably engaged with the second shift fork 42 through an outer peripheral groove. Then, the axial movement of the second shift shaft 41 is transmitted to the second shift ring 40 via the second shift fork 42. As a result, the second shift ring 40 is connected to the first reverse rotation gear 37 and the second reverse rotation gear 37.
The position is freely changeable between a power transmission position in which both the reverse rotation gears 38 are spline-fitted and a neutral position in which only the first reverse rotation gear 37 is fitted. A peripheral groove 44 is provided on one outer circumference of the second shift shaft 41 at two positions in the axial direction.
A ball 45 that can be freely inserted into and removed from is embedded in the partition wall 29, and is biased in the fitting direction by a compression spring 46 so that it can be positioned between a power transmission position and a neutral position.

On the outer periphery of the traveling system transmission shaft 10, the transmission gear 1 on the outer periphery of the main shaft 7
Four transmission gears 47, 48, 4 that mesh with 2, 13, 14, 15 respectively
9,50 is fitted freely on the outside. Further, collars 51 and 52 are fitted onto the outer periphery of the traveling system transmission shaft 10 so that they cannot rotate relative to each other, and shift rings 53 and 54 are axially movable and cannot rotate relative to the collars 51 and 52 via splines. It is fitted over. Each shift ring 53, 54 is a traveling system shifter 5
5, the shift shaft 56 and the shift fork 57 are moved in the axial direction, and the power transmission position meshes with both one of the speed change gears 47, 48, 49, 50 and one of the collars 51, 52, and any of the speed change gears. The position can be freely changed to a neutral position where it does not mesh.

Next, the operation of the first, second, and third shifters 23, 39, and 26 is performed by the shift operating device shown in FIGS. 1, 2, and 6.

That is, the mission case 2 has a vertical axis gear shifting operation shaft.
58 is inserted rotatably in the vertical axis direction and rotatable about the axis, and is supported by the upper wall of the case 2 and the midway portion so as not to move in the radial direction.

A tubular holding bracket 59 is externally fitted to the portion of the gear shift operation shaft 58 that projects outward from the transmission case 2. The holding bracket 59 is fixed to the upper surface of the mission case 2. On the outer periphery of this holding bracket 59,
A cylindrical rotary bracket 62 is fitted onto the outer circumference of the O-rings 60 and 61 so as to be relatively rotatable. Further, collars 63 and 64 are externally fitted to the holding bracket 59 at the upper and lower positions of the rotating bracket 62, and a clip 65 is hooked above the upper collar 63. Directional movement is restricted.

Further, as shown in FIG. 6, a connecting bracket 66 is provided on the outer periphery of the rotating bracket 62 so as to extend outward, and the upper end of the connecting bracket 66 is centered on the horizontal shaft 67 at a middle portion of the gear shift operation lever 3. Is swingably connected to. Also,
One end of the gear shift operation lever 3 is connected to the upper end of the gear shift operation shaft 58 so as to be relatively swingable about a horizontal shaft 68.

As a result, when the operation lever 3 is swung about the horizontal axis as shown by the phantom line in FIG. 6, the shift operation shaft 58 is axially moved. Further, when the operation lever 3 is rocked around the vertical axis, the gear shift operation shaft 58 is rotated around the axis. When the gear shift operation shaft 58 rotates, the rotation bracket 62 also rotates in association with the operation lever 3 and the connection bracket 66.

Here, positioning means for the axial position of the gear shift operation shaft 58 is provided. That is, as shown in FIG. 1 and FIG. 8, three positioning grooves 69 are provided on the outer periphery of the gear shift operation shaft 58 in parallel in the axial direction, and positioning balls 70 that can be inserted into and removed from the grooves 69 are provided. It is held in the through hole 71 (notch) of the holding bracket 59.

Further, the distance between the inner peripheral surface of the rotary bracket 62 and the bottom of the positioning groove 69 of the speed change operation shaft 58 is made substantially equal to the diameter of the positioning ball 70, and when the rotary bracket 62 rotates relative to the holding bracket 59. The inner peripheral surface of the rotary bracket 62 contacts the positioning ball 70 to prevent the positioning ball 70 from coming off the positioning groove 69.

A compression coil spring 72 that biases the positioning ball 70 in the fitting direction into the positioning groove 69 is held by the rotating bracket 62. In order to hold the spring 72, the rotating bracket 62 is provided with an outwardly projecting holding cylinder 73, the spring 72 is housed in the holding cylinder 73, and the radial outward opening 74 of the holding cylinder 73 is screwed with a screw body 75. This is done by closing and pressing the spring 72. Then, between the positioning ball 70 and the spring 72, an auxiliary ball 76 which is in spherical contact with the opening edge of the through hole 71 of the holding bracket 59 when the rotating bracket 62 relatively rotates with respect to the holding bracket 59 is interposed. The auxiliary ball 76 is held by the holding cylinder 73 of the rotating bracket 62.

By this positioning means, the positioning groove 69 at three positions in the axial direction is provided.
The positioning ball 70 is inserted into and removed from the position, and the shift operation shaft 58 is positioned at three axial positions. When the gear shift operation shaft 58 is rotated about its axis, as shown in FIG.
By engaging the positioning ball 70 and the auxiliary ball 76 with each other through the spherical surface, the gear shift operation shaft 58 can be smoothly rotated. That is, when the auxiliary ball 76 is not interposed as shown in FIGS. 10 and 11, the spring 72 is
The rotation of 58 disengages the positioning ball 70, making it difficult to engage the spring 72 with the positioning ball 70 again. On the other hand, by interposing the auxiliary ball 76, the speed change operation can be facilitated.

Then, as shown in FIG. 1, a bending arm 77 is attached to the lower end of the speed change operation shaft 58 by a bolt, and the lower end of the bending arm 77 is projected outwardly and radially downward of the speed change operation shaft 58 to engage the engaging portion. It is said to be 78. The engagement portion 78 is selectively engaged with and disengaged from the first shifter 23, the second shifter 39, and the third shifter 25, and as shown in FIG. It is composed of an engaging portion 79 and a second circular engaging portion 80 that projects rightward. The first engaging portion 79 is disengaged from the first shifter 23 and the third shifter 25, and the second engaging portion 80 is disengaged from the second shifter 39.

That is, the first shift shaft 28, the second shift shaft 41, the third
Engaging bodies 81, 82, 83 are attached to the shift shaft 34,
Front and rear bifurcated engaged parts 84, 85, 86 are formed on each of the engaging bodies 81, 82, 83 so as to be vertically separated from each other. This bifurcated engaged part
The engaging portions 79 and 80 are engaged and disengaged between the 84, 85 and 86 by the axial movement of the speed change operation shaft 58, so that the engagement and disengagement is performed, and the axial position is positioned by the positioning means. At the axial positions of the shift shafts 28, 41 and 34 when the engagement and disengagement is performed, the shift rings 24, 40 and 26 are in the neutral position.

The engaging body 82 of the second shifter 39 is a first engaging body 87 directly attached to the second shift shaft 41 with a bolt, and a first engaging body 87 that is swingably attached to the mission case 2 via a pivot 88 of the longitudinal axis. It is composed of two engaging bodies 89. The engaged body 85 is formed at the left end of the second engaging body 89, and the first engaging body
The right end of the second engaging body 89 is fitted and locked in the recess 90 formed in the lower opening 87.

Then, as shown in FIG. 1, when the gear shift operation shaft 58 is rotated about the axis with the engaging portion 78 and the second shifter 39 engaged,
The second shift shaft 41 is pushed in the radial direction of the speed change operation shaft 58 to move in the axial direction, the second shift ring 40 moves from the neutral position to the power transmission position, and the rotation of the main shaft 7 is reversely changed.
It is transmitted to the PTO transmission shaft 8.

Further, when the speed change operation shaft 58 is axially moved upward from the state shown in the first illustration to engage with the first shifter 23 or the third shifter 25, and then is rotated around the axis, the first shift shaft 28
Alternatively, the third shift shaft 34 is axially moved in the radial direction of the gear shift operation shaft 58, the first shift ring 24 or the third shift ring 26 is in the power transmission position, and the rotation of the main shaft 7 remains the same. , And are transmitted at different speeds to the PTO system transmission shaft 8.

The engaged parts of the first shifter 23 and the second shifter 39
Since the vertical separation distance between 84 and 85 is small, the engaging portion 78 may simultaneously engage both engaged portions 84 and 85, and in this case, both shifters 23 and 39 move to the power transmission position. Means are provided to regulate the

That is, the engaging portions 81, 83 of the first shifter 23 and the third shifter 25 are provided at the upper ends of the engaging bodies 81, 83, respectively, and at the lower ends of the speed change operation shafts 58, which are engageable and disengageable. As shown in FIG. 2, the hooking portion 91 has recesses 92, 93 each having a semi-arcuate shape in plan view at the upper ends of the engaging bodies 81, 83. The shaft 58 is inserted and removed by axial movement. Then, in the state where the engaging portion 78 and the second shifter 39 are engaged, the vertical thicknesses of the recesses 92, 93 are determined so that the speed change operation shaft 58 is inserted between the recesses 92, 93. Engaging part 78 and second
When the shift operation shaft 58 moves upward until it is completely disengaged from the shifter 39, the gear shift operation shaft 58 comes out of the recesses 92 and 93. As a result, even if the gear shift operation shaft 58 is rotated about its axis with the engaging portion 78 engaged with both the first shifter 23 and the second shifter 39, the gear shift operation shaft 58 moves in the radial direction. Is controlled by the mission case 2, the first shift shaft 28 does not move in the radial direction of the speed change operation shaft 58, and both shifters 23 and 39 are kept in the neutral position and cannot move to the power transmission position. Absent. As a result, power is not transmitted to the PTO transmission shaft 8 from both forward and reverse directions, and damage to the transmission is prevented.

The recess 93 of the engaging body 83 of the third shifter 25 is not always necessary, but it is assumed that the recess 93 has a bottom surface 94, and the lower end surface of the speed change operation shaft 58 comes into contact with the bottom surface 94, whereby the gear shift operation is performed. Unnecessary downward movement of the operating shaft 58 is restricted.

Further, the hooking portion 91 may be provided on the second shifter 39.

According to the present invention, when the auxiliary ball 76 comes into contact with the positioning ball 70, the positioning ball 70 is urged by the spring 72 in a direction to be fitted into the positioning groove 69. By applying a force in the axial direction via the operation lever 3, the positioning ball 70 can be disengaged from the positioning groove 69 against the biasing force of the spring 72.
It is possible to easily and surely perform the axial positioning of, and it is possible to obtain the following unique effects.

That is, according to the present invention, when the gear shift operation shaft 58 and the rotary bracket 62 are rotated relative to the holding bracket 59 by operating the operation lever 3, the positioning ball 70 is positioned by the inner peripheral surface of the rotary bracket 62. It is possible to prevent the gear shifting operation shaft 58 from moving in the axial direction by preventing the gear shifting operation shaft 58 from being disengaged from the groove 69, and to provide another mechanism for regulating the axial movement of the gear shifting operation shaft 58. Since it is possible to prevent the shift operation shaft 58 from being accidentally operated in the axial direction without providing the auxiliary ball 76, the auxiliary ball 76 spherically contacts the opening edge of the through hole 71 of the holding bracket 58.
The rotation operation of the speed change operation shaft 58 and the rotation bracket 62 can be facilitated, and since the auxiliary ball 76 is held by the rotation bracket 62, the holding bracket
Even when the rotary bracket 62 rotates with respect to the 58, the auxiliary ball 76 and the spring 72 rotate together with the rotary bracket 62, so that the auxiliary ball 76 and the spring 72 are not disengaged from each other. The rotation operation of the operation shaft 58 can be facilitated.

[Brief description of drawings]

1 to 9 relate to an embodiment of the present invention. FIG. 1 is a front sectional view of a gear shift operating device, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 4 and 5 are the same plane sectional view, FIG. 5 is a front sectional view showing the arrangement of the shifter, FIG. 6 is an explanatory view showing the movement of the shift operation lever, and FIG. 7 is a side view of the main part of the tractor. 8 and 9 are plan sectional views showing the positioning means of the speed change operation shaft in different states, and FIG.
FIG. 11 and FIG. 11 are plan cross-sectional views showing the positioning means of the speed change operation shaft according to the comparative example in different states. 3 …… Operation lever, 59 …… Holding bracket, 62 …… Rotating bracket, 69 …… Positioning groove, 70 …… Positioning ball, 72 …… Spring, 76 …… Auxiliary ball.

Claims (1)

[Scope of utility model registration request] 1. A shift operating shaft (58), which is radially inward of a cylindrical holding bracket (59) and is axially movable and rotatable about the holding bracket (59), and a holding bracket. The retaining bracket (5
Axial movement is restricted with respect to 9) and the shift operation shaft (58)
A rotation bracket (62) interlockingly connected via an operating lever (3) so as to rotate in conjunction with, and a plurality of positioning grooves (69) are axially juxtaposed on the speed change operation shaft (58),
The positioning ball (7
0) is held in a through hole (71) formed in the holding bracket (59), and a spring (72) for urging the positioning ball (70) in the fitting direction into the positioning groove (69) has a rotating bracket (72). 62), the auxiliary ball (76) held by the rotating bracket (62) is interposed between the positioning ball (70) and the spring (72), and is held by the holding bracket (59). On the other hand, when the rotating bracket (62) rotates relative to each other, the inner peripheral surface of the rotating bracket (62) prevents the positioning ball (70) from coming off the positioning groove (69) and the auxiliary ball (76) passes through. A gear shifting operation device, which is configured to make spherical contact with the opening edge of the hole (71).