JP4450673B2 - Walking type work machine - Google Patents

Description

  The present invention relates to a walking type working machine that supports an engine at a front portion of a transmission case and includes traveling wheels at a lower portion of the transmission case.

  In the walking type work machine, for example, as disclosed in Patent Document 1, when the engine power is transmitted to the transmission case (1 in FIGS. 2, 3 and 4 of Patent Document 1), Some shift shafts (14, 14a, 15, 15a in FIGS. 2, 3 and 4 of Patent Document 1) for shifting the power transmitted to the case protrude laterally outward from the upper part of the transmission case. In Patent Document 1, a transmission lever (8 in FIGS. 3 and 4 of Patent Document 1) is swingably supported on the lateral outer side of the upper part of the transmission case, and the shift shaft is slid by the transmission lever. To shift the power transmitted to the transmission case.

Japanese Utility Model Publication No. 57-74824 (Figs. 2, 3 and 4)

In Patent Document 1, the shift shaft protrudes laterally outward from the upper part of the transmission case, and the base of the transmission lever is disposed on the lateral outer side of the upper part of the transmission case. The width is relatively large.
It is an object of the present invention to compactly organize the upper part of the transmission case and the vicinity of the base of the shift lever in a walking type working machine that supports the engine at the front part of the transmission case and has wheels for traveling at the lower part of the transmission case. It is said.

[I]
(Constitution)
A first feature of the present invention resides in the following configuration in a walking work machine having an engine supported on the front part of a mission case and a traveling wheel provided on the lower part of the mission case.
Comprises a transmission shaft to which power of the engine is transmitted to the interior of the upper portion of the transmission case, fitted around the shift gear of the gear change slidably to the shift shaft, above said transmission shaft in the interior of the transmission case and includes a shift shaft in front of the said transmission shaft, and said shift fork is operated to slide externally fitted slidably to the shift shaft shift gear, the shift fork, a boss portion to be fitted on said shift shaft A first engaging portion that extends obliquely rearward and downward from the boss portion and engages the shift gear; and a second engagement that extends rearward from the boss portion and has a lever engaging portion formed at the tip portion. and a coupling portion, the front end portion of the speed change lever is engaged with the lever engaging portion, the gear shift lever towards after beyond above the transmission shaft from the engagement portion to the lever engaging portion before and extending Transmission shaft swingably is supported by the transmission case in side after the further the shift lever is protruded rearward from the support portion to the transmission case, the shift fork slide operably by said shift lever It is configured .

(Function)
According to the first aspect of the present invention, when the transmission shaft and the shift gear to which the engine power is transmitted are provided in the upper part inside the transmission case, the shift shaft and the shift fork are provided on the upper front side of the transmission shaft inside the transmission case. The shift lever extends backward from the shift fork.
Thus, according to the first feature of the present invention, the shift shaft does not protrude laterally outward from the upper part of the transmission case, and the base of the transmission lever is not disposed laterally outward of the upper part of the transmission case. The base of the shift shaft and the shift lever is disposed within the range of the horizontal width of the upper portion of the gearbox, and the horizontal width in the vicinity of the upper portion of the transmission case and the base of the shift lever is suppressed.
As described above, when the transmission shaft and the shift gear to which engine power is transmitted are provided in the upper part inside the transmission case, the transmission lever is provided with the shift shaft and the shift fork on the upper rear side of the transmission shaft inside the transmission case. If it is configured to extend rearward from the shift fork, the front and rear width of the upper part of the mission case may become large.
On the other hand, according to the first feature of the present invention, when the transmission shaft and the shift gear to which engine power is transmitted are provided in the upper part inside the transmission case, the transmission case is located above the transmission shaft inside the transmission case and from the transmission shaft. In addition, a shift shaft and a shift fork are provided on the front side, and the shift lever extends rearward from the position where the lever is engaged with the lever, beyond the upper portion of the shift shaft. Thus, according to the first feature of the present invention, the transmission shaft, the shift gear, and the base portion of the transmission lever are arranged so as to overlap in a plan view, so that the front-rear width of the upper portion of the transmission case is suppressed.

(The invention's effect)
According to the first feature of the present invention, in a walking type working machine that supports an engine at a front portion of a transmission case and has wheels for traveling at a lower portion of the transmission case, the upper portion of the transmission case and the vicinity of the base portion of the transmission lever are provided. The lateral width is reduced, the front and rear width of the upper part of the mission case is reduced, and the upper part of the mission case and the vicinity of the base of the speed change lever can be compactly integrated.

[II]
(Constitution)
The second feature of the present invention resides in the following configuration in the walking work machine of the first feature of the present invention.
The shift shaft includes a front shift shaft and a rear shift shaft, and the front and rear shift shafts are located above the transmission shaft and in front of the transmission shaft. Side shift shafts arranged side by side, the shift fork comprising a front shift fork externally fitted to the front shift shaft and a rear shift fork externally fitted to the rear shift shaft, the front shift A first engaging portion of the fork extends obliquely downward and downward from a boss portion fitted on the front shift shaft through the lower side of the rear shift shaft and engages with the shift gear. A second engagement member provided at the rear shift fork with a lever engagement portion formed at the tip thereof extending rearwardly from the boss portion over the rear shift shaft. Joint lever It is then located above the engaging portion.
[III]
(Constitution)
A third feature of the present invention resides in the following configuration in the walking work machine according to the first or second feature of the present invention.
The mission case is formed in an inverted V shape in a side view, and the wheel is provided at the lower front portion of the mission case, and a rotary tiller is provided at the lower rear portion of the mission case. A front transmission shaft that transmits power to the wheels and a rear transmission shaft that transmits power to the rotary tiller, and the transmission shaft is a front-rear intermediate portion between the front transmission shaft and the rear transmission shaft. And the transmission shaft is constituted by an input shaft through which power from the engine is input to the transmission case.

[IV]
(Constitution)
A fourth feature of the present invention resides in the following configuration in the walking work machine according to any one of the first to third features of the present invention.
Wherein the support for supporting swingably the shift lever is Bei Ete above a and the rearward of the transmission shaft of the transmission shaft definitive in the transmission case.

(Function )
According to the fourth aspect of the present invention, when the transmission shaft and the shift gear to which the engine power is transmitted are provided in the upper part inside the transmission case, as described in [I] above, the transmission shaft of the transmission case inside the transmission case is provided. In addition to the shift shaft and the shift fork provided above and in front of the speed change shaft, a shift lever support portion is provided above the speed change shaft in the transmission case and behind the speed change shaft . Thus, according to the fourth aspect of the present invention, the transmission shaft and the shift gear, the shift shaft and the shift fork, and the support portion of the transmission lever are arranged compactly in an inverted triangle shape in a side view.

(Effect of the invention )
According to the fourth aspect of the present invention, the shift shaft and the shift gear, the shift shaft and the shift fork, and the support portion of the shift lever are arranged in an inverted triangular shape in a side view, and the upper portion of the transmission case and the shift lever It became advantageous in terms of compacting near the base.

[1]
As shown in FIGS. 1 and 2, a front frame 2 is connected to a front portion of an inverted V-shaped mission case 1 in a side view, and an engine 3 is supported on the front frame 2. The right and left wheels 4 for traveling are provided, the rotary tiller 5 is provided at the lower part of the rear part of the mission case 1, and the steering handle 6 is connected to the upper part of the rear part of the mission case 1, so that the walking work machine Is configured.

  As shown in FIGS. 1, 3, and 4, an output shaft 7 protrudes from the engine 3 to the left lateral outer side, and an output pulley 8 is fixed to the output shaft 7. The mission case 1 is configured in two parts, a right part 1R and a left part 1L, and the right and left parts 1R, 1L of the mission case 1 are connected by bolts. An input shaft 9 (corresponding to a transmission shaft) is rotatably supported at an upper portion inside the mission case 1, and the input shaft 9 protrudes from the left side portion 1 </ b> L of the mission case 1 to the left lateral outer side. An input pulley 10 is fixed to the input shaft 9, and a transmission belt 11 is wound around the output and input pulleys 8 and 10.

  As shown in FIGS. 3 and 4, a flange portion 1a is integrally formed at the front portion of the left side portion 1L of the mission case 1, and a boss portion 1b is integrally formed at the flange portion 1a. An operating shaft 12 is rotatably supported on the boss 1 b of the mission case 1, a washer 13 and a retaining clip 14 are attached to one end of the operating shaft 12, and the other end of the operating shaft 12. A tension arm 15 (L-shaped in a side view) is fixed to the tension arm 15, and a tension pulley 16 is provided at the end of the tension arm 15. As shown in FIGS. 1 and 2, a clutch lever 17 is swingably supported around the horizontal axis P <b> 1 of the steering handle 6, and a wire 18 is connected between the tension arm 15 and the clutch lever 17. And a spring 19 that urges the tension arm 15 downward (in a direction in which the tension pulley 16 moves away from the transmission belt 11).

  As a result, when the clutch lever 17 is operated backward and the steering handle 6 and the clutch lever 17 are held together by hand, the wire 18 is pulled and the tension arm 15 is operated upward (the tension pulley 16 is Power is transmitted from the output shaft 7 to the input shaft 9 by being pressed by the transmission belt 11. When the hand is released from the clutch lever 17, the tension arm 15 is operated downward (the direction in which the tension pulley 16 is separated from the transmission belt 11), and the power from the output shaft 7 to the input shaft 9 is cut off.

[2]
Next, the structure of the transmission system to the right and left wheels 4 and the rotary tiller 5 in the mission case 1 will be described.
As shown in FIGS. 5, 6, and 7, the transmission shafts 20, 21, and 22 are rotatably supported inside the transmission case 1, and the first speed gear 23 and the second speed gear 24 are fixed to the transmission shaft 20, A third speed gear 25 having large and small diameter gears is externally fitted to the transmission shaft 20 so as to be relatively rotatable. A reverse gear 26 having large and small diameter gears is externally fitted to the transmission shaft 22 so as to be relatively rotatable, and the small diameter gear of the reverse gear 26 is engaged with the second speed gear 24. A transmission gear 28 having large and small diameter gears is fitted on the transmission shaft 21 so as to be relatively rotatable, and a transmission gear 27 formed integrally with the transmission shaft 20 is engaged with the large diameter gear of the transmission gear 28. The small-diameter gear of the transmission gear 28 meshes with the large-diameter gear of the third speed gear 25. A transmission gear 37 fixed to the transmission shaft 21 meshes with a small diameter gear of the third speed gear 25.

  As shown in FIG. 5, right and left axles 29 are rotatably supported at the lower part of the mission case 1 and are fixed to the right and left wheels 4 on the right and left axles 29. 29 is provided with a differential mechanism 30. A sprocket 31 is integrally formed on the transmission shaft 21, a sprocket 32 is fixed to the differential mechanism 30, and a transmission chain 33 is wound around the sprockets 31 and 32.

  As shown in FIGS. 5 and 7, shift gears 34 and 35 are externally fitted to the input shaft 9 by a spline structure so as to be integrally rotatable and slidable. The shift gear 34 is in a first speed position F1 meshed with the first speed gear 23, a reverse position R meshed with the large diameter gear of the reverse gear 26, and a neutral position N not meshed with both the large diameter gears of the first speed gear 23 and the reverse gear 26. Operable. The shift gear 35 is a neutral position that does not mesh with both the second gear position F2 that meshes with the second gear 24, the third gear position F3 that meshes with the large gear of the third gear 25, and the large gear of the second gear 24 and the third gear 25. It can be freely operated at position N.

  As shown in FIGS. 5, 6, and 7, when the shift gear 34 is operated to the first speed position F1, the power of the input shaft 9 is changed to the shift gear 34, the first speed gear 23, the transmission shaft 20, the transmission gears 27, 28, and the third speed gear. 25, the transmission gear 37, the transmission shaft 21, the transmission chain 33, and the differential mechanism 30 are transmitted to the right and left wheels 4 in the forward first speed state. When the shift gear 34 is operated to the reverse position R, the power of the input shaft 9 is changed to the shift gear 34, the reverse gear 26, the second speed gear 24, the transmission shaft 20, the transmission gears 27 and 28, the third speed gear 25, the transmission gear 37, and the transmission shaft. 21, it is transmitted to the right and left wheels 4 in the reverse state via the transmission chain 33 and the differential mechanism 30.

  As shown in FIGS. 5, 6, and 7, when the shift gear 35 is operated to the second speed position F2, the power of the input shaft 9 is changed to the shift gear 35, the second speed gear 24, the transmission shaft 20, the transmission gears 27 and 28, and the third speed gear. 25, the transmission gear 37, the transmission shaft 21, the transmission chain 33, and the differential mechanism 30 are transmitted to the right and left wheels 4 in the forward second speed state. When the shift gear 35 is operated to the third speed position F3, the power of the input shaft 9 is transmitted in the third forward speed state via the shift gear 35, the third speed gear 25, the transmission gear 37, the transmission shaft 21, the transmission chain 33, and the differential mechanism 30. It is transmitted to the right and left wheels 4.

  As shown in FIGS. 5, 7, and 8, a transmission gear 38 having large and small diameter gears is externally fitted to the transmission shaft 20 so as to be relatively rotatable, and the transmission gears 39 and 60 are fixed to the transmission shaft 22. The small-diameter gear of the transmission gear 38 and the transmission gear 39 are engaged with each other. As shown in FIG. 1, a tilling shaft 40 is rotatably supported at a lower portion of the rear portion of the mission case 1, and a plurality of tilling claws 5 a are provided on the tilling shaft 40 to constitute a rotary tilling device 5. . As shown in FIGS. 5, 7, and 8, the sprocket 41 is integrally formed on the transmission shaft 22, the sprocket 42 is fixed to the tilling shaft 40, and the transmission chain 43 is wound around the sprockets 41 and 42. ing.

  As shown in FIGS. 5, 7, and 8, the shift gear 36 is externally fitted to the input shaft 9 so as to be integrally rotatable and slidable by a spline structure. The shift gear 36 can be operated to a forward rotation position that meshes with the large diameter gear of the transmission gear 38, a reverse rotation position that meshes with the transmission gear 60, and a neutral position N that does not mesh with both the large diameter gear of the transmission gear 38 and the transmission gear 60. .

  As shown in FIGS. 5, 7, and 8, when the shift gear 36 is operated to the forward rotation position, the power of the input shaft 9 is transmitted via the shift gear 36, the transmission gear 38, the transmission gear 39, the transmission shaft 22, and the transmission chain 43. It is transmitted to the rotary tiller 5 (cultivation shaft 40) in the forward rotation state. When the shift gear 36 is operated to the reverse rotation position, the power of the input shaft 9 is transmitted to the rotary tiller 5 (cultivation shaft 40) in the reverse rotation state via the shift gear 36, the transmission gear 60, the transmission shaft 22 and the transmission chain 43. .

[3]
Next, the differential mechanism 30 will be described.
As shown in FIGS. 5 and 9, the differential mechanism 30 includes a differential case 30a, a pinion gear 30b rotatably supported by the differential case 30a, and a bevel gear 30c fixed to the right and left axles 29. The sprocket 32 is formed in a flat plate shape, and a spline-shaped occlusal portion 32a is formed on the inner peripheral portion of the central opening, and the sprocket 32 is connected to the side surface of the differential case 30a of the differential mechanism 30 by a bolt. .

  As shown in FIGS. 5 and 9, a shift member 44 is externally fitted to the left axle 29 so as to be integrally rotatable and slidable by a spline structure. An operation shaft 45 is rotatably supported around the horizontal axis P1 inside the winding path of the transmission chain 33 between the transmission shaft 21 and the differential mechanism 30, and the shift fork 46 (boss portion 46a) is operated on the operation shaft. The shift fork 46 is engaged with the shift member 44. An inclined surface cam portion 46b is formed on the boss portion 46a of the shift fork 46, a pin 45a is fixed to the operation shaft 45, and the cam portion 46b of the shift fork 46 is abutted against the pin 45a of the operation shaft 45. 9 is provided with a spring 47 that urges the shift fork 46 to the left in FIG. 9 (the side where the shift member 44 is separated from the engagement portion 32a of the sprocket 32).

  As shown in FIGS. 5, 8, 9, and 10, an operation shaft 49 is rotatably supported around a horizontal axis P <b> 2 at the top of the mission case 1 (above the upper surfaces of the right and left wheels 4). A wire 50 is connected across the arm 45 b fixed to the operation shaft 45 and the arm 49 a fixed to the operation shaft 49. As shown in FIGS. 1 and 2, the steering handle 6 is provided with a differential lock lever 51, and a wire 52 is connected between the arm 49 b fixed to the operation shaft 49 and the differential lock lever 51.

  The state shown in FIGS. 5 and 9 is a state in which the shift member 44 is separated from the occlusal portion 32 a of the sprocket 32, and is an operating state of the differential mechanism 30. When the wire 52 is pulled by operating the differential lock lever 51 (see FIG. 1) from the state shown in FIGS. 5 and 9, the operation shaft 49 is rotated, the wire 50 is pulled, and the operation shaft 45 is moved. It is rotated. When the operation shaft 45 is rotated in this way, the shift fork 46 is operated to the right in the drawing of FIG. 9 by the cam action of the pin 45a of the operation shaft 45 and the cam portion 45b of the shift fork 46, and the shift member 44 engages with the occlusal portion 32 a of the sprocket 32. As a result, the differential mechanism 30 enters the differential lock state.

[4]
Next, the operation structure of the transmission lever 58 and the shift gears 34 and 35 will be described.
As shown in FIGS. 10 and 11, two shift shafts 53 and 54 are arranged in the front-rear direction on the upper front side of the input shaft 9 inside the mission case 1. A shift fork 55 (boss portion 55a) is slidably fitted to the shift shaft 53, and the shift fork 55 extends obliquely rearward and downward to engage the shift gear 34. The shift fork 55 and the shift gear 34 are moved to the first speed. A ball-type detent mechanism 55 b that is held at the position F 1, the reverse position R, and the neutral position N is provided on the boss portion 55 a of the shift fork 55. The boss portion 55a of the shift fork 55 is provided with the lever engaging portion 55c, a lever engaging portion 55c of the shift fork 55 is extended to the plane left in FIG 11. A portion that extends obliquely rearward and downward from the boss portion 55a and engages with the shift gear 34 corresponds to a first engagement portion of the shift fork 55, and a portion where the lever engagement portion 55c is formed is the portion of the shift fork 55. It corresponds to the second engaging part.

As shown in FIGS. 10 and 11, the shift fork 56 (boss portion 56 a) is slidably fitted on the shift shaft 53, and the shift fork 56 extends obliquely rearward and downward to engage the shift gear 35. A boss portion 56 a of the shift fork 56 is provided with a ball-type detent mechanism 56 b that holds the shift fork 56 and the shift gear 35 at the second speed position F 2, the third speed position F 3, and the neutral position N. An engaging portion 56 c is provided on the boss portion 56 a of the shift fork 56, and the engaging portion 56 c of the shift fork 56 is located above the lever engaging portion 55 c of the shift fork 55. A portion that extends obliquely rearward and downward from the boss portion 56 a and engages with the shift gear 35 corresponds to a first engagement portion of the shift fork 56, and a portion where the lever engagement portion 56 c is formed corresponds to the shift fork 56. It corresponds to the second engaging part.

As shown in FIGS. 10 and 11, the shift fork 57 (boss portion 57 a) is slidably fitted on the shift shaft 54, and the shift fork 57 extends obliquely rearward and downward to engage the shift gear 36. A boss 57a of the shift fork 57 is provided with a ball-type detent mechanism 57b that holds the shift fork 57 and the shift gear 36 in the forward rotation position, the reverse rotation position, and the neutral position N. The boss portion 57a of the shift fork 57 is provided with lever engaging portions 57c and 57d. The lever engaging portion 57c of the shift fork 57 is located below the lever engaging portion 55c of the shift fork 55, and The engaging portion 57d is located above the engaging portion 56c of the shift fork 56. A portion that extends obliquely rearward and downward from the boss portion 57a and engages with the shift gear 36 corresponds to the first engagement portion of the shift fork 57, and a portion where the lever engagement portion 57d is formed is the portion of the shift fork 57. It corresponds to the second engaging part.

  As shown in FIGS. 1 and 3, a support portion 1 c having a semicircular cross section is integrally formed at the upper rear side of the input shaft 9 in the upper portion of the mission case 1. Further, by connecting the left side portions 1R and 1L, a cylindrical support portion 1c is provided at the upper rear side of the input shaft 9 in the upper portion of the mission case 1. A shift lever 58 is provided, and a fulcrum 58a provided near the base of the shift lever 58 is supported on the support portion 1c of the transmission case 1 so as to be swingable up and down and left and right.

  As shown in FIG. 10, the base portion of the transmission lever 58 extends from the support portion 1c of the mission case 1 to the front (to the left in FIG. 10) beyond the input shaft 9, so that the transmission lever 58 is The case 1 extends from the support portion 1c so as to protrude rearward (to the right in FIG. 10). As shown in FIGS. 2 and 10, a lever guide 59 having an opening for guiding the speed change lever 58 is fixed to the upper portion of the transmission case 1, and the speed change lever 58 passes rearward through the lever guide 59 (FIG. 10). (In the transmission case 1), the transmission lever 58 extends rearward over the input shaft 9 and the transmission lever 58 protrudes rearward from the transmission case 1. State).

[5]
Next, the operation of the shift gears 34 and 35 by the speed change lever 58 will be described.
10, 11, and 12 are states in which the shift gears 34, 35, and 36 are operated to the neutral position N, and the base portion of the transmission lever 58 is engaged with the engaging portion 56 c of the shift fork 56. It is. When the speed change lever 58 is operated to the second and third speed positions F2 and F3 of the lever guide 59 from the states shown in FIGS. 10, 11 and 12, the shift fork 56 and the shift gear 35 are operated to the second and third speed positions F2 and F3. (The second forward speed and the third forward speed state) (the shift gears 34 and 36 are left at the neutral position N (the rotary tiller 5 is stopped)).

When the speed change lever 58 is operated upward from the state shown in FIGS. 10, 11, and 12, the base portion of the speed change lever 58 is separated from the engagement portion 56 c of the shift fork 56 and engages with the lever engagement portion 55 c of the shift fork 55. . Accordingly, when the shift lever 58 is operated to the first speed and the reverse positions F1, R of the lever guide 59, the shift fork 55 and the shift gear 34 are operated to the first speed and the reverse positions F1, R (first forward speed and reverse state). (The shift gears 35 and 36 remain in the neutral position N (the rotary tiller 5 is stopped)).

As shown in FIG. 12, when the speed change lever 58 is operated to the first speed position F1 of the lever guide 59 and operated upward, the base of the speed change lever 58 is separated from the lever engaging portion 55c of the shift fork 55 and the shift fork 57 Engage with the lever engaging portion 57c. Thus, as shown in FIGS. 10 and 11, when the shift lever 58 is operated to the forward and reverse positions of the lever guide 59, the shift gear 34 remains in the first speed position F1 (the first forward speed state). 36 is operated to the normal rotation and reverse rotation positions (the normal rotation and reverse rotation states of the rotary tiller 5) (the shift gear 35 remains in the neutral position N).

When the speed change lever 58 is operated to the second speed position F2 of the lever guide 59 and moved downward from the state shown in FIGS. 10, 11, and 12, the base of the speed change lever 58 moves away from the engaging portion 56 c of the shift fork 56. The fork 57 is engaged with the lever engaging portion 57d. Thus, when the shift lever 58 is operated to the second speed forward rotation position F2 (forward) of the lever guide 59, the shift gear 36 is moved to the forward rotation position with the shift gear 35 remaining at the second speed position F2 (forward second speed state). Operated (forward rotation state of the rotary tiller 5) (the shift gear 34 is left in the neutral position N).

[First Alternative Embodiment of the Invention]
Instead of the structure of the shift shafts 53 and 54 shown in FIG. 10 and FIG. 11 in the above-mentioned [Best Mode for Carrying Out the Invention], a configuration as shown in FIG. 13 and FIG.
As shown in FIGS. 13 and 14, the shift shaft 54 (see FIGS. 10 and 11) is eliminated, and a single shift shaft 53 is provided on the upper front side of the input shaft 9 inside the mission case 1. Separate shift forks 55, 56, 57 are used.

As shown in FIGS. 13 and 14, the shift fork 55 (boss portion 55 a) is slidably fitted on the shift shaft 53, and the shift fork 55 extends obliquely rearward and downward to engage the shift gear 34. A boss 55a of the shift fork 55 is provided with a ball-type detent mechanism 55b that holds the shift fork 55 and the shift gear 34 at the first speed position F1, the reverse position R, and the neutral position N. A lever engaging portion 55c is provided on the boss portion 55a of the shift fork 55, and the lever engaging portion 55c of the shift fork 55 extends to the left in FIG. A portion that extends obliquely rearward and downward from the boss portion 55a and engages with the shift gear 34 corresponds to a first engagement portion of the shift fork 55, and a portion where the lever engagement portion 55c is formed is the portion of the shift fork 55. It corresponds to the second engaging part.

As shown in FIGS. 13 and 14, a shift fork 56 (boss portion 56 a) is slidably fitted on the shift shaft 53, and the shift fork 56 extends obliquely rearward and downward to engage the shift gear 35. A boss portion 56 a of the shift fork 56 is provided with a ball-type detent mechanism 56 b that holds the shift fork 56 and the shift gear 35 at the second speed position F 2, the third speed position F 3, and the neutral position N. An engaging portion 56 c is provided on the boss portion 56 a of the shift fork 56, and the engaging portion 56 c of the shift fork 56 is located above the lever engaging portion 55 c of the shift fork 55. A portion that extends obliquely rearward and downward from the boss portion 56 a and engages with the shift gear 35 corresponds to a first engagement portion of the shift fork 56, and a portion where the lever engagement portion 56 c is formed corresponds to the shift fork 56. It corresponds to the second engaging part.

As shown in FIGS. 13 and 14, a shift fork 57 (boss portion 57 a) is slidably fitted to the shift shaft 53, and the shift fork 57 extends obliquely rearward and downward to engage the shift gear 36. A boss 57a of the shift fork 57 is provided with a ball-type detent mechanism 57b that holds the shift fork 57 and the shift gear 36 in the forward rotation position, the reverse rotation position, and the neutral position N. The boss portion 57a of the shift fork 57 is provided with lever engaging portions 57c and 57d. The lever engaging portion 57c of the shift fork 57 is located below the lever engaging portion 55c of the shift fork 55, and The lever engaging portion 57d is located above the lever engaging portion 56c of the shift fork 56. A portion that extends obliquely rearward and downward from the boss portion 57a and engages with the shift gear 36 corresponds to the first engagement portion of the shift fork 57, and a portion where the lever engagement portion 57d is formed is the portion of the shift fork 57. It corresponds to the second engaging part.

As shown in FIGS. 13 and 14, the lengths of the boss portions 55a, 56a, 57a of the shift forks 55, 56, 57 are shorter than those of [Best Mode for Carrying Out the Invention] (see FIG. 11). Therefore, when the shift gear 34 is operated to the neutral position N, the shift gear 35 can be operated to the second speed and third speed positions F2, F3, and the shift gear 35 is operated to the neutral position N. If so, the shift gear 34 can be operated to the first speed and the reverse positions F1, R.
Structures other than the above structure are configured in the same manner as the above-mentioned [Best Mode for Carrying Out the Invention].

[Second Embodiment of the Invention]
In place of the structure in the vicinity of the input shaft 9, the transmission shafts 20 and 22, and the shift shafts 53 and 54 in the above-mentioned [Best Mode for Carrying Out the Invention] [First Alternative Embodiment of the Invention], FIG. You may comprise as shown in FIG.
As shown in FIGS. 15 and 16, the first speed gear 23 (see FIGS. 5, 6, and 7) is abolished, and another reverse gear 26 is externally fitted to the transmission shaft 22 so as to be relatively rotatable. The reverse gear 26 includes a large-diameter and a small-diameter gear, and the small-diameter gear of the reverse gear 26 is engaged with the second-speed gear 24. The shift gear 34 (see FIGS. 5 and 7) has been abolished, the second gear position F2 (the third gear 25 is used for the second gear) where the shift gear 35 meshes with the large diameter gear of the third gear 25, and the neutral position N The first speed position F1 meshed with the second speed gear 24 (the second speed gear 24 is used for the first speed), the neutral position N, and the reverse position R meshed with the large diameter gear of the reverse gear 26 are configured to be freely operated. .

  As shown in FIGS. 15 and 16, when the shift gear 35 is operated to the first speed position F1, the power of the input shaft 9 is changed to the shift gear 35, the second speed gear 24, the transmission shaft 20, the transmission gears 27 and 28, and the third speed gear 25. , The transmission gear 37, the transmission shaft 21, the transmission chain 33, and the differential mechanism 30 are transmitted to the right and left wheels 4 in the forward first speed state. When the shift gear 35 is operated to the reverse position R, the power of the input shaft 9 is changed to the shift gear 35, the reverse gear 26, the second speed gear 24, the transmission shaft 20, the transmission gears 27 and 28, the third speed gear 25, the transmission gear 37, and the transmission shaft. 21, it is transmitted to the right and left wheels 4 in the reverse state via the transmission chain 33 and the differential mechanism 30. When the shift gear 35 is operated to the second speed position F2, the power of the input shaft 9 is transmitted in the forward second speed state via the shift gear 35, the third speed gear 25, the transmission gear 37, the transmission shaft 21, the transmission chain 33, and the differential mechanism 30. It is transmitted to the right and left wheels 4.

As shown in FIGS. 17 and 18, the shift shaft 54 (see FIGS. 10 and 11) is abolished, and one shift shaft 53 is provided on the upper front side of the input shaft 9 inside the mission case 1. The shift fork 55 (see FIGS. 10 and 11) is abolished, and another shift fork 56, 57 is used. A shift fork 56 (boss portion 56a) is slidably fitted to the shift shaft 53, and the shift fork 56 extends obliquely rearward and downward to engage the shift gear 35. The shift fork 56 and the shift gear 35 are moved to the second speed. A ball-type detent mechanism 56 b that holds the position F 2, the neutral position N, the first speed position F 1, the neutral position N, and the reverse position R is provided on the boss portion 56 a of the shift fork 56. A lever engaging portion 56c is provided on the boss portion 56a of the shift fork 56, and the lever engaging portion 56c of the shift fork 56 extends to the left in FIG. A portion that extends obliquely rearward and downward from the boss portion 56 a and engages with the shift gear 35 corresponds to a first engagement portion of the shift fork 56, and a portion where the lever engagement portion 56 c is formed corresponds to the shift fork 56. It corresponds to the second engaging part.

As shown in FIGS. 17 and 18, a shift fork 57 (boss portion 57 a) is slidably fitted on the shift shaft 53, and the shift fork 57 extends obliquely rearward and downward to engage the shift gear 36. A boss 57a of the shift fork 57 is provided with a ball-type detent mechanism 57b that holds the shift fork 57 and the shift gear 36 in the forward rotation position, the reverse rotation position, and the neutral position N. Lever engaging portion 57c on the boss portion 57a of the shift fork 57 and is provided with a lever engaging portion 57c of the shift fork 57 is located below the lever engaging portion 56c of the shift fork 56. A portion that extends obliquely rearward and downward from the boss portion 57 a and engages with the shift gear 36 corresponds to a first engagement portion of the shift fork 57, and a portion where the lever engagement portion 57 c is formed is the portion of the shift fork 57. It corresponds to the second engaging part.

  As shown in FIG. 18, the base of the speed change lever 58 extends from the support portion 1c of the transmission case 1 to the front (to the left of the ground in FIG. 18) over the input shaft 9, and the speed change lever 58 is It extends from the support portion 1c of the case 1 so as to protrude rearward (to the right in FIG. 18). As shown in FIGS. 18 and 19, a lever guide 59 having an opening different from the lever guide 59 (see FIG. 12) is fixed to the upper portion of the transmission case 1, and the speed change lever 58 passes through the lever guide 59. Is extended rearward (to the right in FIG. 18) (in the transmission case 1, the transmission lever 58 extends rearward over the input shaft 9, and the transmission lever 58 is connected to the transmission case 1. Protruding rearward from the top).

15, 17, and 18 are states in which the shift gears 35 and 36 are operated to the neutral position N, and the base portion of the transmission lever 58 is engaged with the lever engaging portion 56 c of the shift fork 56. is there. Accordingly, as shown in FIGS. 15, 17, and 19, when the shift lever 58 is operated to the first speed, the second speed and the reverse positions F1, F2, and R of the lever guide 59, the shift fork 56 and the shift gear 35 are moved to the first speed, The speed and reverse positions F1, F2, and R are operated (first forward speed, second forward speed and reverse state) (the shift gear 36 remains in the neutral position N (the rotary tiller 5 is stopped)).

When operating above the shift lever 58 as described above is operated to the first speed position F1 of the lever guide 59, the lever engaging the shift fork 57 the base of the shift lever 58 moves away from the lever engaging portion 56c of the shift fork 56 Engage with the portion 57c. As a result, as shown in FIGS. 15, 17, and 19, when the shift lever 58 is operated to the forward and reverse positions of the lever guide 59, the shift gear 35 remains in the first speed position F <b> 1 (forward first speed state), The shift gear 36 is operated to the normal rotation and reverse rotation positions (normal rotation and reverse rotation states of the rotary tiller 5).
Structures other than the above structure are configured in the same manner as the above-mentioned [Best Mode for Carrying Out the Invention].

[ Third Another Embodiment of the Invention]
In the above-mentioned [Best Mode for Carrying Out the Invention] [First Alternative Embodiment ] [ Second Alternative Embodiment], the rotary tiller 5 is provided at the bottom of the rear portion of the transmission case 1 from the beginning. Although the present invention is a walking type working machine, the present invention is a walking type working machine in which a rotary tiller 5 or another working device is detachably configured to a hitch (not shown) provided at the rear part of the mission case 1. Is also applicable.

Overall side view of walking type work machine Overall plan view of walking type work machine Side view near the top of the mission case Top view near the top of the mission case Longitudinal rear view of mission case (transmission system to right and left wheels) Partial rear view of the mission case Longitudinal rear view near the shift gear of the transmission case Longitudinal rear view of the transmission case (power transmission system to the rotary tiller) Longitudinal rear view near the differential mechanism of the mission case Longitudinal side view near the shift shaft at the top of the mission case Transverse plan view near the shift axis at the top of the mission case Rear view of lever guide In the first alternative embodiment of the invention, a longitudinal side view of the vicinity of the shift shaft at the top of the mission case In the first alternative embodiment of the invention, a cross-sectional plan view near the shift shaft at the top of the mission case In the second alternative embodiment of the invention, a longitudinal rear view near the shift gear of the transmission case In the second alternative embodiment of the invention, a partial longitudinal rear view of the mission case In the second alternative embodiment of the invention, a cross-sectional plan view near the shift gear of the transmission case In the second alternative embodiment of the invention, a longitudinal side view of the vicinity of the shift shaft at the top of the mission case In a second alternative embodiment of the invention, rear view of the lever guide

1 Mission Case 1c Mission Case Support 3 Engine 4 Wheel
5 Rotary tillage device
9 shift shaft (input shaft)
20 Transmission shaft (front transmission shaft)
22 Transmission shaft (rear transmission shaft)
34, 35, 36 Shift gear 5 3 shift shaft (rear shift shaft)
54 Shift shaft (front shift shaft)
5 5 shift fork (rear shift fork)
55c Lever engaging part
56 shift fork (rear shift fork)
56c lever engaging part
57 Shift fork (front shift fork)
57d Lever engaging part 58 Shift lever

Claims (4)

A walk-type working machine that supports an engine at the front of a mission case and has traveling wheels at the bottom of the mission case,
Comprises a transmission shaft to which power of the engine is transmitted to the interior of the upper portion of the transmission case, fitted around the shift gear of the gear change slidably to the shift shaft, above said transmission shaft in the interior of the transmission case and includes a shift shaft in front of the said transmission shaft, a shift fork slid the shift gear is externally fitted slidably to the shift shaft,
A boss portion that is externally fitted to the shift shaft, a first engagement portion that extends obliquely rearward and downward from the boss portion and engages the shift gear, and extends rearward from the boss portion. And a second engaging part having a lever engaging part formed at the tip part,
The front end portion of the speed change lever is engaged with the lever engaging portion, the gear shift and extend the shift lever towards after beyond above the transmission shaft from the engagement portion to the lever engaging portion swingably is supported by the transmission case in rearward of the axis, further, the shift lever is protruded rearward from the support portion to the transmission case, a slide operably configured the shift fork by the shift lever A walking work machine. The shift shaft includes a front shift shaft and a rear shift shaft, and the front and rear shift shafts are located above the transmission shaft and in front of the transmission shaft. Deploy side shift shafts side by side,
The shift fork includes a front shift fork that is externally fitted to the front shift shaft, and a rear shift fork that is externally fitted to the rear shift shaft. From the boss part that is externally fitted to the front shift shaft, it extends obliquely rearward and downward through the lower side of the rear shift shaft and engages with the shift gear, and the second engagement part of the front shift fork is connected to the boss part. A lever engaging portion that extends beyond the rear shift shaft and extends rearward is formed above the lever engaging portion of the second engaging portion provided in the rear shift fork. The walking type working machine according to claim 1, wherein the walking type working machine is positioned. The mission case is formed in an inverted V shape in a side view, and the wheel is provided at the lower front portion of the mission case, and a rotary tiller is provided at the lower rear portion of the mission case. A front transmission shaft that transmits power to the wheels, and a rear transmission shaft that transmits power to the rotary tiller.
The transmission shaft is disposed above a front-rear intermediate portion of the front transmission shaft and the rear transmission shaft, and the transmission shaft is an input shaft through which power from the engine is input to the transmission case. The walk type work machine according to claim 1 or 2 constituted. Wherein the support portion for supporting the shift lever swingably, in any one of claims 1 to 3 that is provided on the rear side of the upper a and the transmission axis of the transmission shaft definitive in the transmission cases Walking type work machine.

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