JPH0759408A - Controller - Google Patents

Abstract

PURPOSE:To surely prevent accident due to backward traveling in a state where a working machine is driven. CONSTITUTION:This controller 80 for returning traveling speed change lever to neutral position N by interlocking with 'on' operation of a working operation lever 15 when a traveling speed change lever is located at backward step R and returning the working operation lever 15 to 'off' position by interlocking with 'off' change over operation of the traveling speed change lever to backward stage R is provided on a traveling gear change shift shaft 41 of a traveling variable speed gear 12 for carrying out change over between a forward step F1 and a backward step R through the traveling gear change shift shaft 41 by operation of the traveling speed change lever.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a management machine having a working machine attached to a machine body and used for agricultural work such as tilling, soil filling, ridge and trench digging.

[0002]

2. Description of the Related Art Conventionally, this type of management machine has a traveling transmission that switches between a forward speed and a reverse speed by operating a traveling speed change lever, and a PT that switches power to a PTO shaft by operating a work operation lever.
A device having an O-axis switching device is known.

[0003]

However, in the above-described management machine, when the traveling speed change lever is positioned in the reverse gear and the vehicle is traveling in the reverse direction, the work operation lever is erroneously operated to operate, for example, the PTO shaft. When a working machine such as a rotary device that is linked to the vehicle is driven, the vehicle travels in reverse with the rotary device being driven, and it is not necessary to drive the rotary device during such reverse travel. When a person travels backward while checking the rear, there is a problem that the rotary pawl is caught in the rotary pawl and the safety is insufficient. Further, when the work operation lever is in the operation position, even if the travel speed change lever is erroneously switched to the reverse speed, the rotary device is driven to perform the reverse travel, which is the same as the case described above. There was a problem.

An object of the present invention is to provide a management machine which can ensure the safety of the worker when the vehicle is traveling in the reverse direction without traveling backward while the operating machine is driven.

[0005]

In order to achieve the above object, the present invention provides a traveling speed change mode in which a forward speed F1, F2 and a reverse speed stage R are switched through a traveling speed change shift shaft 41 by operating a traveling speed change lever 11. Machine 12 and PTO shaft switching device 17 for turning on and off power to PTO shaft 16 by operating work operation lever 15
In the management machine including the above-mentioned work operation lever 15, when the travel change gear shift shaft 41 is positioned at the reverse gear R, the work operation lever 15 is turned on and off when the work operation lever 15 is turned on. Interfering with traveling speed shift shaft 41
Is returned to the neutral position N and the work operation lever 15 is in the operation position, the operation operation lever 15 interferes with the work operation lever 15 by the operation of switching the travel speed change shift shaft 41 to the reverse gear R. A control body 80 for returning the work operation lever 15 to the off position is provided.

[0006]

With the above construction, when the traveling speed change lever 11 is used to move the traveling speed change shift shaft 41 to the reverse speed R and the vehicle is traveling in the reverse direction, the work operation lever 15 is erroneously operated to operate the PTO.
When attempting to drive a working machine that is interlocked with the shaft 16, the traveling body shift shift shaft 41 can be returned to the neutral position N by the control body 80 to stop the backward traveling, and the work operation lever 15 is operated. When the traveling gear shift lever 11 is erroneously switched to the reverse gear R by the traveling gear shift lever 11 in the operating position, the control body 80 returns the work operating lever 15 to the off position and the working machine. Therefore, it is possible to prevent the vehicle from traveling backward while driving the working machine, and to sufficiently secure the safety of the worker when traveling backward.

[0007]

FIG. 4 shows the overall structure of a management machine according to the present invention. This management machine has an engine 2 equipped with a cylinder head 21, a muffler 22 and the like mounted on the front upper part of the machine body 1 and 1, a mission case 3 is connected to the rear side of the mission case 3 to support mainly one traveling wheel 4 on the lower front side of the mission case 3, and a rotary device 5 on the lower rear side as an example of various working devices. A handle support frame 62 having a handle 61 is attached to the upper side of the case 3 through a handle attachment base 6 having an open U-shaped cross section and extending toward the upper rear side. Further, the traveling wheels 4 and the rotary device 5 are interlocked with the engine 2 via a transmission case 7 and a transmission mechanism 10 provided in the transmission case 3. That is,
As shown in FIG. 5, a transmission belt 3b is hung between a drive pulley 2a provided on the engine 2 and an input pulley 3a provided on the mission case 3, and power is transmitted to the inside of the mission case 3. The mechanism 10 is built in, and the rotational power input to the input pulley 3 a via the power transmission mechanism 10 is transmitted to the traveling wheels 4 and the rotary device 5.

As shown in FIGS. 5, 6 and 7, the power transmission mechanism 10 includes a traveling transmission 12 for switching between forward gears F1 and F2 and reverse gear R by operating a traveling gear shift lever 11. The auxiliary transmission 14 is operated by operating the auxiliary transmission lever 13 to switch between the high and low stages, and the work operating lever 15 is used to transfer power to the PTO shaft 16 to the normal high and low 2 stages and the reverse high and low 2 stage. P consisting of a work transmission that switches to and from position
TO-axis work switching device (hereinafter referred to as work transmission device) 17
And a PTO shaft on / off device 19 for turning on / off the power to the PTO shaft 16 by operating the work on / off lever 18, and the transmission case 3 includes a main shaft 20 to which the input pulley 3a is fixed, The intermediate shaft 21, the auxiliary shaft 22, the reduction shaft 23, and the PTO shaft 16 are rotatably supported.
In FIG. 6, the main shaft 20, the intermediate shaft 21, the auxiliary shaft 22, and the reduction shaft 23 are shown so that the structure of the power transmission mechanism 10 can be easily understood.
FIG. 3 is a cross-sectional view in which the PTO shaft 16 is irregularly developed, and a traveling transmission case 35, which will be described later, which is originally located in the front is unfolded in the rear.

In the main shaft 20, a spline portion 20a provided on one side of the input pulley side is provided with two large and small gears 2.
A work machine forward rotation transmission gear 24 having 4a, 24b and a shift hawk locking portion 24c is movably supported only in the axial direction, and a forward low speed first gear 25 is provided at an intermediate portion and forward forward high speed is provided on the other side portion. The second gear 26 is fixed.

The intermediate shaft 21 has a spline portion 21a provided on one side thereof and two large and small gears 27a which are selectively meshed with the first and second gears 25 and 26 of the main shaft 20, respectively.
A main transmission gear 27 having a shift fork engaging portion 27c and a shift fork 27c is provided so as to be movable only in the axial direction, a third gear 28 for high speed is provided in an intermediate portion of the intermediate shaft 21, and a low speed gear is provided on the other side portion. The fourth gear 29 is fixed.

A large gear 30a and a small gear 30b, which are constantly meshed with the large gear 24a of the working machine forward rotation transmission gear 24, are provided at a spline portion 22a provided on one side of the auxiliary shaft 22.
And a work machine reverse rotation speed change gear 30 having a shift hawk locking portion 30c so as to be movable only in the axial direction, a fifth reverse gear 31 is provided in an intermediate portion of the auxiliary shaft 22, and another auxiliary shaft 22 is provided. An auxiliary transmission gear 32 having two large and small gears 32a and 32b selectively meshing with the third and fourth gears 28 and 29 of the intermediate shaft and a shift hawk engaging portion 32c is attached to the spline portion 22b provided on the side. Supported so that it can move only in the direction,
Moreover, the other side end of the counter shaft 22 is extended outward from the mission case 3 and the drive sprocket 33 for the traveling wheel 4 is provided on the projecting portion, while the drive sprocket 33 is attached to the mission case 3 at one end. The traveling transmission case 35, which is internally mounted on the side and rotatably supports the axle 34 of the traveling wheel 4, is fixed to the other end, and the driven sprocket 36 facing the drive sprocket 33 is provided on the axle 34.
A chain 37 is hung between the drive sprocket 33 and the driven sprocket 36 to transmit the rotational power of the sub shaft 22 to the traveling wheels 4.

On the reduction shaft 23, two large and small gears 38a and 38b are selectively meshed with the large and small gears 24a and 24b of the work machine forward rotation transmission gear 24 or the large and small gears 30a and 30b of the work machine reverse rotation transmission gear 30. Is provided with a reduction gear body 38, and the spline portion 1 is attached to the PTO shaft 16.
A switching gear 39 having an interlocking gear 39a that meshes with a small gear 38b of the reduction gear body 38 and a shift fork locking portion 39b is supported on the 6a so as to be movable only in the axial direction, and the P
One end of the TO shaft 16 is projected to the outside of the mission case 3, and the cultivating shaft (not shown) of the rotary device 5 is attached to the projection.
A drive sprocket 40 that transmits power to the vehicle is provided.

Further, near the intermediate shaft 21 in the transmission case 3, a traveling shift shift shaft 41 operated by a traveling shift lever 11 is movably supported in the axial direction as shown in FIGS. 6 and 7. Then, the front end portion of the first shift fork 42 attached to the shift shaft 41 is locked to the locking portion 27c of the main transmission gear 27, and the shift shaft 41 is moved in the axial direction in accordance with the operation of the traveling speed change lever 27. The main transmission gear 27 is moved in the axial direction via the first shift fork 42,
The large gear 27a of the main transmission gear 27 meshes with the first forward gear 25 of the main shaft 20 to move to the first forward stage F1, and the small gear 27b of the main transmission gear 27 moves to the second forward gear 26 of the main shaft 20. The forward transmission F12 can be switched to the reverse gear R by meshing with the forward second gear F2 and by meshing the large gear 27a of the main transmission gear 27 with the reverse fifth gear 31 of the auxiliary shaft 22. I am configuring.

Secondary shaft 22 in the mission case 3
A sub-shift shift shaft 47 operated by the sub-shift lever 13 is movably supported in the axial direction in the vicinity of
The tip portion of the second shift fork 48 attached to the No. 7 is locked to the locking portion 32c of the auxiliary transmission gear 32, and the auxiliary transmission lever 1
By the axial movement of the auxiliary transmission shift shaft 47 in accordance with the operation of 3, the auxiliary transmission gear 32 is axially moved with respect to the auxiliary shaft 22 via the second shift fork 48, and the large and small gears 32a of the auxiliary transmission gear 32, By selectively engaging 32b with the third and fourth gears 28, 29 of the intermediate shaft 21, the rotational speed of the rotational power of the main shaft 20 transmitted from the auxiliary shaft 22 to the traveling wheels 4 via the intermediate shaft 21 is increased. Or, switch to low speed, and use the aircraft 1
The auxiliary transmission 14 is configured so that the traveling speed can be selected between high speed and low speed.

Further, above the main shaft 20 in the mission case 3, the work machine forward rotation shift shift shaft 49 and the work machine reverse rotation shift shift shaft 50 operated by the work operation lever 15 are provided.
Are arranged side by side so as to be movable in the axial direction, and the tip end portion of the third shift fork 51 attached to the forward rotation shift shaft 49 is locked to the locking portion 24c of the work machine forward rotation shift gear 24. By the axial movement of the work operation lever 13, the large gear 24a of the work machine forward rotation transmission gear 24 is passed through the third shift fork 51.
Is a forward rotation high speed position where the small gear 38b of the reduction gear body 38 meshes, a neutral position where the large and small gears 24b of the work machine forward rotation transmission gear 24 do not mesh with any of the reduction gear body 38, and the work machine forward rotation transmission gear 24. The small gear 24b can be shifted to the forward rotation low speed position in which the large gear 38a of the reduction gear body 38 is meshed, and the tip end portion of the fourth shift hawk 52 mounted on the reverse rotation shift shaft 50 is connected to the work machine reverse transmission gear. Locking part 3 of 30
0c, and the work operation lever 13 axially moves the large gear 30a of the working machine reverse rotation transmission gear 30 through the fourth shift fork 52 to the small gear 38 of the reduction gear body 38.
Reverse rotation high-speed position in which b and the work machine reverse rotation transmission gear 3
No. 0 large and small gears 30a and 30b do not mesh with any of the reduction gear bodies 38, and the work machine reverse rotation transmission gear 30.
Of the reduction gear body 38 so that the small gear 30b can be switched to the reverse rotation low speed position in which the small gear 30b meshes with the large gear 38a of the reduction gear body 38.
Make up 7.

Near the PTO shaft 16 in the mission case 3, a switching shift shaft 53 operated by a work on / off lever 18 is movably supported in the axial direction, and is mounted on the shift shaft 53. The leading end of the hawk 54 is locked to the locking portion 39b of the switching gear 39, and the on / off lever 1
By the axial movement of the shift shaft 53 for switching accompanying the operation of 8, the switching gear 39 is axially moved through the fifth shift fork 54, and the switching gear 39 is moved by the reduction gear body 3.
Working position where the small gear 38b of No. 8 meshes, and the switching gear 3
The work on / off device 18 is configured so that 9 can be selected to a work off position where it does not mesh with the small gear 38b of the reduction gear body 38.

Further, as shown in FIG. 8, the traveling speed change lever 11 has a V-shape having a vertical base 11a, and the traveling speed change lever 11 is provided on one side of the handle mount 6. The member 55 is swingably supported via the base portion 11a, and the base portion of the traveling speed change lever 11 is projected below the support member 55, and an operating piece 57 extending in the front-rear direction is provided on the protruding portion. , One side portion of the travel transmission shift shaft 41 on the input pulley side is projected outward from the transmission case 3, and an engaging body 55 having a U-shape in plan view having an engaging groove 55a is formed on the protruding portion of the shift shaft 41 upward. On the other hand, the distal end portion 57a of the operation piece 57 of the traveling speed change lever 11 is engaged with the engagement groove 55a of the engaging body 55, and the traveling speed change shift shaft is swung to move the traveling speed change shift shaft. 41 So that is moved in the axial direction. As shown in FIG. 9, between the traveling speed shift shaft 41 and the mission case 3, the traveling speed shift shaft 41 is provided.
Is provided with a position holding mechanism 43 that holds the position at a moving position of five stages in the axial direction. In this case, in the first stage shown in FIG. 9 in which the traveling speed shift shaft 41 is moved to the input pulley side by the position holding mechanism 43 to the maximum, the large gear 27a of the main speed gear 27 and the fifth gear of the auxiliary shaft 22 are moved. It is held in the reverse gear R where it meshes with the gear 31, and in the second gear, the main transmission gear 27 is held in the first neutral position N where it does not mesh with any gear.
At the first stage, the large gear 27a of the main transmission gear 27 is held at the first forward stage F1 which meshes with the first low speed forward gear 25 of the main shaft 20, and at the fourth stage, the main transmission gear 27 meshes with any gear. Not held at the second neutral position N, and at the fifth step, the small gear 27a of the main transmission gear 27 is held at the second forward step F2 that meshes with the second forward speed high gear 26 of the main shaft 20. As the position holding mechanism 43, five engagement recesses 41a are formed adjacent to each other on the traveling speed shift shaft 41, and the engagement recesses 41a are formed from the mounting side of the input pulley 3a to the reverse gear R and the first neutral position. The position N, the first forward step F1, the second neutral position N, and the second forward step F2 are provided, while the transmission case 3 is provided with one hole portion 44 corresponding to the engaging concave portion, and the hole portion 44 is provided with the ball 45 and the ball 45. Spring 4 for biasing ball 45 toward the engaging recess And interior and the pressing engagement by the spring 46 to the engaging recess 41a of the ball 46, and to hold the switching stage position.

As shown in FIGS. 1, 2 and 3, the work operation lever 15 has one side portion of the traveling speed shift shaft 41 opposite to the input pulley side projected to the outside of the mission case 3. The rotating cylinder 58 is rotatably supported by the projecting portion and is also provided on the mission case 3.
It is supported immovably in the axial direction by a, and a cylinder shaft 59 is fixed to the lower part of the outer periphery of the rotary cylinder 58 in a direction orthogonal to the rotary cylinder 58, and a pivot shaft 60 is attached to the cylinder shaft 59. While the work operation lever 15 is provided so as to freely swing, the other side of the working machine forward / reverse shift shafts 49, 50 opposite to the input pulley side is projected outward from the mission case 3, and 1 at which the work operation lever 15 can be engaged with the projecting end portion
By providing piece bodies 61 and 62 having a pair of flange portions 61a and 62b, the work operation lever 15 is swung in the circumferential direction of the traveling shift shift shaft 41, that is, in the machine front-rear direction via the rotary cylinder 58. Accordingly, one of the work machine forward rotation shift shaft 49 and the work machine reverse rotation shift shaft 50 is selected and engaged with the frame body, and the work operation lever 15 is moved from the engaged position.
By swinging in the circumferential direction of the cylinder shaft 59, that is, in the left-right direction of the machine body through the pivot shaft 60, either one of the forward and reverse shift shafts is moved in the axial direction to select either high speed or low speed. It is configured to do. In this case, a position holding mechanism 63 for holding the shift position of the forward and reverse rotation shift shafts 49 and 50 by the work operation lever 15 is provided between the work machine forward and reverse rotation shift shafts 49 and 50 and the mission case 3. Has been. As shown in FIG. 10, the position holding mechanism 63 includes the forward rotation shift shaft 49 and the reverse rotation shift shaft 5.
In the forward rotation shift shaft 49, three engaging recesses 49a and 50a are formed adjacent to each other. The position N is not the forward rotation high speed stage. Further, in the reverse rotation shift shaft 50, the three engagement recesses 50a are formed from the input pulley side to the reverse rotation low speed stage, the neutral position N, and the reverse rotation high speed stage, while the mission case 3 is used. Is provided with a through hole 64 corresponding to both the engaging recesses 49a, 50a of the forward and reverse shift shafts 49, 50, and a pair of balls 65, 66 and both balls 65 are provided in the through hole 64. , 66 are internally provided with springs 67 for urging the engagement recesses, and the gear positions are maintained by engaging the balls 65, 67 with arbitrary engagement recesses. In this case, when one of the forward and reverse shift shafts 49, 50 moves and one ball disengages from the engaging recess, the coil spring 67 is compressed so as to come into close contact with it. The close contact length is set so that the other shift shaft cannot move in this state, so that the forward and reverse shift shafts 49 and 50 are not moved at the same time to perform a gear shift operation. The work transmission 17 is prevented from being damaged.

The auxiliary shift lever 13 and the work on / off lever 18 are provided on the handle side of the handle 61, and as shown in FIGS. 8 and 11, one side of the shift shift shaft 47 and the switching shift shaft 53 on the input pulley side. Of the crank 68, 69 supported by the mission case 3 so as to be swingable, and the other end of each of the cranks 68, 69 is sub-shifted. Lever 1
3 and the work on / off lever 18 are interlockingly connected via the operation wires 70 and 71, and the shift shift shaft 47 or the switching shift via the cranks 68 and 69 is operated by operating the sub shift lever 13 or the work on / off lever 18. Auxiliary shift or P that shifts the shaft 53 in the axial direction to switch between the high and low stages described above.
The power of the TO shaft 16 can be turned on and off.

In FIG. 5, 72 is a work operation lever 15.
It is a guide plate provided with the shift guide groove 72a.

When the traveling speed shift shaft 41 of the traveling transmission 12 is positioned in the reverse gear R, the work operation lever 15 is operated to interfere with the traveling speed shift shaft 41 when the traveling speed shift shaft 41 is in the reverse gear R. Drive gear shift shaft 41
When the work operation lever 15 is returned to the neutral position N and the work operation lever 15 is in the operation position, the reverse gear R of the traveling speed change lever 11
There is provided a control body 80 which interferes with the work operating lever 15 by the switching operation to and returns the work operating lever 15 to the neutral position, in other words, the off position.

As shown in FIGS. 1, 2 and 3, the control body 80 includes a boss portion 81 which can be fitted into the other side protruding end portion of the traveling speed shift shaft 41, and the boss portion 81. A portion that extends in the vertical direction from the outer periphery of 81 and that is wider than the swing width when the work operation lever 15 is switched to the work machine forward / reverse shift shafts 49, 50 and that projects inward at both upper and lower end portions. And a control portion 82 having a U-shape in side view having contact portions 82a and 82b. The control body 80 is attached to the other side protruding end portion of the traveling speed change lever shaft 41, and the upper and lower contact portions 82a and 82a of the control portion 82. 8
2b is inserted and fixed via a boss 81 so that the outer side portion of the work operation lever 15 always faces, and as shown by the solid line in FIG. When the work operation lever 15 is in the neutral position at the closest reverse speed R, the vertical contact portions 82a, 82b of the control body 80 and the work operation lever 15 do not interfere with each other, and the traveling speed shift shaft 41 moves backward. At the stage R, when the work operation lever 15 is at the forward rotation high speed position or the reverse rotation high speed position,
The upper contact portion 82a of the control body 80 and the work operation lever 15
Interfere with each other, and the travel transmission shift shaft 41 moves to the reverse gear R
When the work operation lever 15 is in the normal rotation low speed position or the reverse rotation low speed position, as shown by the phantom line in FIG.
The lower contact portion 82b of 0 and the lower portion of the work operation lever 15 are arranged at a position where they interfere with each other. In this case, when the traveling gear shift shaft 41 is located at the first neutral position N,
Since the vertical contact portions 82a, 82b of the control body 80 are located away from the work operation lever 15 at the positions indicated by the phantom lines, the vertical contact portions 82a, 82b of the control body 80 are shown.
And the work operation lever 15 do not interfere with each other, and moreover, the vertical contact portion 82 is larger than in the case of the first neutral position N.
Also in the case where a and 82b are located at the first neutral position N, the forward first stage F1, the second neutral position N and the forward second stage F2, which are located away from the work operation lever 15, the control body 80
The upper and lower contact portions 82a and 82b do not interfere with the work operation lever 15.

Thus, when it is attempted to shift the work operation lever 15 to the forward rotation or the reverse rotation high speed position with the traveling speed shift shaft 41 positioned in the reverse gear R, the upper portion of the work operation lever 15 is moved to the above-mentioned position. It interferes with the upper contact portion 82a of the control body 80 and pushes the traveling speed shift shaft 41, that is, the traveling speed shift lever 11 back to the first neutral position N, and the traveling speed shift shaft 41 is positioned in the reverse gear R. In this state, when it is attempted to position the work operation lever 15 in the normal rotation or reverse rotation low speed position, the lower portion of the work operation lever 15 interferes with the lower contact portion 82b of the control body 80, and the traveling speed shift shaft 41 That is, the traveling speed change lever 11 is pushed back to the first neutral position N. As a result, when the rotary device 5 is erroneously attempted to be driven during reverse travel, the travel transmission lever 11 can be returned to the first neutral position N and the travel can be forcibly stopped.

On the other hand, when the work operation lever 15 is in the normal rotation or reverse rotation high speed position as shown by the phantom line in FIG. The upper contact portion 82a of 80 interferes with the upper portion of the work operation lever 15 and pushes the work operation lever 15 back to the neutral position N.
When the traveling speed change lever 11 is switched to the reverse gear R when the vehicle is in the normal rotation or reverse rotation high speed position, the lower contact portion 82b of the control body 80 interferes with the lower end portion of the work operation lever 15. The work operation lever 15 is pushed back to the neutral position N. As a result, even when the traveling speed change lever 11 is erroneously switched to the reverse gear R when the work operation lever 15 is in the operation position, the work operation lever 15 is returned to the neutral position and the rotary device 5 is moved. It can be stopped forcibly. As a result, it is possible to prevent the rotary device 5 from being driven during the backward traveling, and to prevent the worker from being caught in the rotary pawls of the rotary device 5 during the backward traveling. Sufficient safety can be ensured.

Further, in the above embodiment, the operation portion of the main speed change lever 11 and the operation portion of the work operation lever 15 are separately arranged on both sides of the mission case 3, and the swing fulcrum portion of the work operation lever 15 is arranged. As the traveling gear shift shaft 41 itself, and the traveling gear shift shaft 41 is used.
In addition, it is possible to control the backward traveling while the rotary device 5 is driven with a simple configuration in which the control body 80 that interlocks with the swinging operation of the work operation lever 15 to the entry position is provided at the reverse stage R position. Since the control mechanism is configured as described above, it is not necessary to specially provide a complicated control mechanism having a special external operation means, the structure thereof can be simplified, and the width dimension of the machine body 1 can be suppressed to be narrow.

In this embodiment, the handle support frame 62 provided with the handle 61 and the traveling speed change lever 11 are
It is attached so that it can change direction in the front-back direction of the machine body 1. In this case, as shown in FIG. 8, an annular spacer 83 having a through hole 83a in the center and a plurality of cutout holes 83b on the outer periphery is supported on the handle mount 61, and the spacer 83 is The handle support frame 62 is inserted into the outer periphery through a through hole 62a formed in the center of the bottom wall of the handle support frame 62, and an annular tightening plate 84 having a diameter larger than that of the spacer 83 is placed on the spacer 83. The tightening plate 84 is fixed to the handle mounting base 6 with a plurality of bolts 85 via a spacer 83, and the handle supporting frame 62 is
The handle support frame 62 with a plurality of engaging holes 62b, and the handle mounting base 6 with a pin 86 that engages with the engaging holes 62b. A lock mechanism 88 including an operating body 87 for engaging and disengaging the pin 86 with respect to the engaging hole 62a.
Is provided. As a through hole for the bolt 85 provided in the spacer 83, a cutout hole 8 opened to the outer periphery as shown in FIG.
Since it is 3b, the spacer 83 is larger than that in the case of forming a round hole.
The outer diameter of the handle support frame 62 can be kept small, and thus the lateral width dimension of the handle support frame 62 can be kept small and the size can be reduced.

As shown in FIG. 8, the structure for enabling the direction change of the traveling speed change lever 11 is such that the support member 56 rotatably supports the tubular body 89 and the lower end of the tubular body 89. To project below the support member 56,
An operation piece 57 extending in the front-rear direction is fixed to the projecting portion, and an inwardly projecting step portion 89a is provided at an intermediate portion in the longitudinal direction of the tubular body 89, and a spline groove is formed on an inner surface of the step portion 89a. While forming 89b, a small diameter portion 11b having a diameter smaller than that of the spline groove 89a is formed at the base end portion of the traveling speed change lever 11.
And the spline portion 1 engaging with the spline groove 89b.
1c and a large diameter portion 11d that engages with the step portion 89a, and a spring 91 is interposed between the washer 90 and the step portion 89a which are provided at the tip of the small diameter portion 11b via a screw. , The spline portion 11c is always provided with the spline groove 89.
It is engaged with b. Thus, the traveling speed change lever 11
When the direction of the lever 11 is changed, the base 11a of the lever 11 is lifted against the spring 91, so that the operation piece 5
The engagement between the spline portion 11c and the spline groove 89b is disengaged without rotating the tubular body 89 to which 7 is fixed, the traveling speed change lever 11 is rotated to an arbitrary position in such a state, and the hand is released at that position. The direction can be changed by engaging the spline portion 11c with the spline groove 89b.

Further, in this embodiment, as shown in FIGS. 5 and 8, a check mechanism 92 is provided for checking the switching of the traveling speed change lever 11 to the high speed stage, that is, the forward two stages F2. This restraint mechanism 92 fixes a generally Z-shaped mounting plate 93 in plan view to one side of the handle mounting base 6, and allows an L-shaped restraining rod 94 to move vertically inside the mounting plate 93. While supporting and urging the restraining rod 94 constantly downward via a spring 95, the upper end of one side wall 93a of the mounting plate 93 is engaged with the upper end of the restraining rod 94, and the restraining rod 94 is A first engaging portion 93b is formed to hold the rear end portion 57a of the operation piece 57 in a state where the rear end portion 57a is located at the time of two forward steps, and the upper end of the intermediate wall 93c is engaged with the upper end portion of the check rod 94. Then, the check rod 94 is attached to the rear end 5 of the operation piece 57.
2nd to hold in the upper restraint release position which does not engage with 7b
The engaging portion 93d is formed. Thus, when the machine body 1 travels in the normal state in which the handle support frame 62 is located on the rear side of the machine body 1, as shown by the solid line in FIG. By engaging the second engaging portion 93d of 93c, the restraint to the two forward stages by the restraining rod 94 is released, and the handle support frame 62 is turned to the front side of the machine body 1. When the machine body 1 is to be traveled while the vehicle is running, the travel speed change lever 11
When the gear is switched to the two forward gears F2, the risk is increased by backing at high speed toward the operator side, so the switching of the traveling speed change lever 11 to the two forward gears F2 is restrained.
In this case, the check rod 94 is lifted upward from the second engaging portion 93d to disengage it, and the upper end of the check rod 94 is brought into the first engaging portion 93b as shown by the phantom line in FIG. Change. As a result, the lower end portion of the check rod 9 projects to the position where the rear end portion 57b of the operation piece 57 is located at the second forward speed, and even if the traveling speed change lever 11 is operated to switch to the second forward speed, the operation is performed. The rear end of the piece 57 abuts on the lower end of the check rod 94 so that the travel speed shift shaft 41
Is prevented from moving to the second forward stage F2.

Further, in the above embodiment, the PTO shaft switching device 17 uses the work transmission device for switching the power to the PTO shaft 16 between the high and low stages of forward rotation, the high and low stages of reverse rotation, and the neutral position. The PTO switching device 17 is not limited to the work transmission device at all, and, for example, a work on / off device for simply turning on / off the power to the PTO shaft 16 may be used as the PTO shaft switching device. In this case, the control body 80 described above may be interposed between the work on / off lever of the work on / off device, that is, the work operation lever and the travel speed shift shaft 41.

[0030]

As described above, according to the present invention, when the traveling gear shift lever 41 is positioned in the reverse gear R and the vehicle is traveling in the reverse direction, the work operation lever 15 is erroneously turned on and off. When it is attempted to drive the working machine linked to the PTO shaft 16, the control body 80 provided on the traveling shift shaft 41 of the traveling transmission 12 returns the traveling shift shaft 41 to the neutral position N. When the reverse traveling can be stopped, and when the work operation lever 15 is in the operating position, the traveling shift lever 11 erroneously switches the traveling shift shaft 41 to the reverse stage R, the control body 80 is operated. The work operation lever 15 can be returned to the off position to stop the work machine. As a result, the work machine is not driven to move backward while the work machine is being driven. 5 can be prevented from or caught in the rotary nail, thereby it is possible to sufficiently ensure the operator's safety.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a main part of a management machine according to the present invention.

FIG. 2 is an explanatory view of a state where the work operation lever is operated to a normal rotation low speed position.

FIG. 3 is a vertical sectional side view of the main part.

FIG. 4 is a side view showing the overall structure of a management machine according to the present invention.

FIG. 5 is a partially omitted plan view of the machine body.

FIG. 6 is a cross-sectional explanatory view in which a power transmission mechanism is appropriately developed.

FIG. 7 is a schematic side sectional view of a power transmission mechanism.

FIG. 8 is a partially cutaway side view showing a mounted state of a traveling speed change lever.

FIG. 9 is a vertical cross-sectional view of a position holding mechanism for a travel shift shaft.

FIG. 10 is a vertical cross-sectional view of a position holding mechanism for the work machine forward and reverse shift shafts.

FIG. 11 is an explanatory diagram of an operation mechanism of a sub-shift shift shaft.

FIG. 12 is a plan view of a spacer.

[Explanation of symbols]

11: traveling speed change lever, 12: traveling speed changer, 15: work operation lever, 17; PTO shaft switching device, 41: traveling speed change shift shaft, 80: control body

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Eiji Yamazaki Inventor Eiji Yamazaki 5-32-7 Sendagaya, Shibuya-ku, Tokyo Ishi Kawashima Shibaura Machinery Co., Ltd.

Claims (1)

[Claims] 1. A travel transmission (12) for switching between a forward speed (F1, F2) and a reverse speed (R) through a travel speed shift shaft (41) by operating a travel speed shift lever (11), and a work operation. In a management machine provided with a PTO shaft switching device (17) for turning on and off power to a PTO shaft (16) by operating a lever (15), a travel speed shift shaft (41) of the travel transmission (12) is provided. When the travel speed shift shaft (41) is located in the reverse gear (R), the operation operation lever (15) is operated to interfere with the work operation lever (15) to move the travel speed shift shaft (41). When the work operation lever (15) is returned to the neutral position (N) and the work operation lever (15) is in the operation position, the travel speed change shift shaft (41) by the travel speed change lever (11).
A control machine (80) provided with a control body (80) for returning the work operation lever (15) to the cut position by interfering with the work operation lever (15) by a switching operation to the reverse gear (R). .