JP2001108094A - Forward/backward changeover mechanism of working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forward/backward changeover mechanism of a working machine that can change from the forward side to the backward side, vice versa, and perform speed increase and reduction in an operation direction substantially to one way without folding the operation direction of an operation lever over an entire range from the forward side to the backward side. SOLUTION: An operation lever 16 is engaged with a forward side transmission member 17 by moving a grabbing portion 16a to a forward operation range side of a neutral operation range, and the operation lever 16 is engaged with a backward side transmission member 18 by moving the grabbing portion to a backward operation range side of the neural operation range to engage the operation lever with the forward or backward side transmission member. This grabbing portion is moved and operated in the forward or backward operation range while keeping the engagement, and a moving amount of this grabbing portion is transmitted to a transmission mechanism 9 through mutually independent transmission routes in the forward operation range or the backward operation range via transmission means 19, 20 connected to respective transmission members.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forward / backward switching mechanism for a working machine such as a snow blower or a cultivator.

[0002]

2. Description of the Related Art A snow plow having a friction disk type continuously variable transmission is disclosed in Japanese Patent Application Laid-Open No. Hei 10-68108. In the snowplow described in this publication, a traveling speed change lever is moved along a guide groove provided substantially in the front-rear direction, and a friction plate (pressed against a disk to which engine rotation is transmitted) is moved. The shift and forward / reverse switching are performed by sliding on the spline shaft and moving the disk in the diameter direction (one side outer peripheral part → center part → other side outer peripheral part) on the disk.

In such a forward / reverse switching structure, the transmission is composed of a disk, a friction plate, or the like, and the friction plate is merely moved diametrically from one outer peripheral side to the other outer peripheral side on the disk. , It is possible to switch from forward high speed → forward low speed → neutral position → reverse low speed → reverse high speed. In connection with this, the movement operation of the travel shift lever can be performed simply by moving the travel shift lever forward and backward. The movement can be easily transmitted to the friction plate via the link mechanism (traveling lever → link → friction plate connection arm → connection ring → friction plate). In the operation of moving the traveling speed change lever in the front-rear direction, the direction and the traveling direction coincide with each other.

[0004]

However, in the forward / reverse switching mechanism using the friction disk type continuously variable transmission mechanism described above,
Since the rotational operation of the traveling speed change lever is transmitted to the friction plate via the same transmission path (traveling speed lever → link → friction plate connection arm → connection ring → friction plate) on both the forward and reverse sides, the traveling speed change is performed. The transmission characteristics of the rotation operation of moving the friction plate in accordance with the amount of rotation operation of the lever become exactly the same on the forward side and the reverse side (if the forward side lever ratio characteristic is determined, the reverse side lever ratio characteristic is inevitable). Will be determined). For this reason, for example, the forward and reverse lever ratios are arbitrarily set independently of each other so that the reverse side travels at a lower speed than the forward side with the same operation amount of rotation of the traveling speed change lever, and both are optimally set. It is difficult to obtain transfer characteristics.

On the other hand, as a single transmission for various vehicles, a gear transmission or a V-belt automatic transmission is used in combination with a shift switching device. In such a transmission, the shift switching device is switched to forward, reverse, or neutral by a shift lever, and in the switched state, the rotation is operated to change the gear ratio with the same shift lever. In this case, the shift lever operation for changing the transmission ratio from the low speed side to the high speed side in the state where the neutral state is switched to the forward or reverse direction is the same direction on both the forward side and the reverse side. Therefore, when switching from forward high speed → forward low speed → neutral position → reverse low speed → reverse high speed by the shift lever, when the shift operation direction of the shift lever shifts from the forward side to the reverse side, it is turned back from the neutral position. It will be turned in the opposite direction. Generally, from the viewpoint of driving operation, the operation path of the shift lever is moved backward by moving the shift lever on the forward side backward to decrease the speed, moving it in the same direction as it is, switching to the reverse side, and turning further in the same direction to reverse. It is preferable that the movement is a one-way forward movement in which the speed increases on the side. However, a conventional gear-type transmission or V-belt automatic transmission is known in which a lever path does not perform a reversing operation to be a reciprocating path and such a one-way forward rotation operation in the same direction drives a forward / reverse drive. It was difficult.

The present invention has been made in consideration of the above-mentioned prior art, and when switching the forward / backward movement and driving the speed change mechanism by the operation lever, the operation direction of the operation lever is folded over the entire range from the forward side to the reverse side. It is an object of the present invention to provide a forward / backward switching mechanism of a working machine capable of switching from a forward side to a reverse side and vice versa in an operation direction substantially in one direction without returning, and capable of increasing / decreasing operation.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an operation lever for switching between forward and backward movement and shifting, and a traveling mechanism which is connected to the operating lever to switch between forward and backward movement and a speed change mechanism. (A): a first operating range in which the operating lever is moved left and right to switch the traveling drive device of the working machine to either the forward side or the reverse side; ): The grip portion of the operation lever is moved from one end of the first operation range to one side substantially orthogonal to the first operation range, and the forward speed increases as the distance from the first operation range increases in accordance with the amount of the movement. And (c) moving the grip of the operating lever from the other end of the first operating range to the other side substantially orthogonal to the first operating range. And the amount of movement A third operation range in which the reverse speed of the work machine is increased or decreased so as to increase the reverse speed as the distance from the first operation range increases. The operating lever is engaged with the forward shifting member by moving the gripping portion to the second operating range side of the operating range, and the gripping portion is moved to the third operating range side of the first operating range to operate. After the lever is engaged with the reverse-side transmission member, and the operation lever is engaged with the forward-side or reverse-side transmission member, the grip is moved within the second or third operation range while maintaining the engagement. , The amount of movement of the gripping portion is controlled by the transmission means connected to each transmission member in the second operation range and the third operation range through independent transmission paths. Shifting Providing forward-reverse switching mechanism of the working machine, characterized in that transmitted to 構部.

According to this configuration, the forward-side transmission member and the reverse-side transmission member for connecting the operation lever to the transmission mechanism are provided, and these forward-side and reverse-side transmission members are constituted by separate members. Since the operation lever is selectively engaged with any one of the transmission levers and the amount of movement of the operation lever is transmitted to the transmission mechanism via independent transmission paths on the forward side and the reverse side, for example, By changing the size and connecting position of the transmission member (the member constituting the transmission path) with respect to the member between the forward side and the reverse side, the transmission characteristic when transmitting the operation amount of the operation lever to the speed change mechanism is changed to the forward side. The reverse side is independent of each other, and can be set arbitrarily and set under optimum conditions for each.

Further, when a transmission such as a gear transmission or an automatic V-belt transmission is used, the transmission or the switching device moves forward and backward in a switching operation of forward high speed → forward low speed → neutral position → reverse low speed → reverse high speed. Even in the case of reciprocating operation at the time of switching, the operation lever can be configured with a simple structure of forward / reverse switching and speed change by one-way forward operation from one side to the other side.

In a preferred embodiment, the forward and reverse transmission members are rotatable about one axis extending in the lateral direction of the machine, and the operation lever is provided on another axis substantially coaxial with the axis. It is characterized in that it is rotatable about a center and is rotatable about another axis extending in a direction substantially perpendicular to the axis.

According to this construction, when the operating lever is engaged with the forward shifting member or the reverse shifting member and then the operating lever is rotated, the engaging portion is rubbed against the engaging portion. Resistance is generated, and accordingly, the rotation operation force does not become heavy and the engaging portion does not wear unevenly. That is, when the operation lever is rotated, the operation lever is not substantially formed as a reciprocating path for returning the operation direction to the opposite direction on the way (including a left-right operation at a neutral position in the middle). The driving operation from the forward side to the reverse side can be performed in the range from one end to the other end by a certain one-way forward movement in the front-rear direction.

When the operating lever is provided so as to protrude in the vertical direction with respect to the body of the work machine, the rotating operation direction is in the front-rear direction with respect to the machine body of the work machine, and horizontally from the wall surface of the machine body. When it is made to protrude, its rotating operation direction is up and down with respect to the machine body of the working machine.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a main part configuration view of the entire snowplow according to the embodiment of the present invention as viewed from the side.

The snow removing machine 1 has a body driving pulley 2 and a snow removing pulley 3 on the output shaft of the engine E. The body driving pulley 2 is connected to a driving pulley 5 via a belt 4, and drives the body through traveling switching and a speed change mechanism as described later. The snow removing pulley 3 is connected to a snow engulfing pulley 7 through a belt 6, scrapes in snow from the front of the fuselage, ejects the snow from a discharge port 8 and discharges the snow.

The drive pulley 5 connected to the engine E is mounted on a drive shaft 59 and drives it to rotate. The drive shaft 59 is connected to a forward / reverse switching device 10 via a continuously variable transmission 9 as will be described later, and drives the drive wheel 11 to rotate so that the truck is wound between the drive wheel 11 and the driven wheel 13. 1
2 to drive the aircraft.

A handle 14 and a control panel 15 are provided at the rear of the aircraft. The control panel 15 has a grip 16 at its tip.
An operation lever 16 provided with a protrudes upward. A substantially fan-shaped forward-side transmission member 17 and a reverse-side transmission member 18 are locked to the lower end of the operation lever 16 as described later. Transmission rods 19 and 20 are separately connected to the forward and reverse transmission members 17 and 18, respectively, and are connected at their lower ends via a shaft 27 and are connected to a common transmission drive link mechanism 21.

The operating lever 16 further includes a switching drive wire 22 for switching the forward / reverse switching device 10.
Are connected as described below.

FIG. 2 is a view of the working machine 1 as viewed from the rear. The operation lever 16 is rotatable around the shaft 24 in the left-right direction as indicated by an arrow A. In conjunction with this operation, the inner wire (not shown) of the switching drive wire 22 is pushed / pulled to switch back and forth. Drive device 10 and drive wheel 1 in the forward or reverse direction via drive shaft 23.
1 (see FIGS. 6 and 8 described later).

The forward and reverse transmission members 17 and 18 are engaged with the operating lever 16 via bent engagement pieces 17a and 18a at the ends thereof. Each locking piece 17a, 18
In FIG. 3A, slits 25 and 26 are formed as shown in FIG. By rotating the operation lever 16 in the lateral direction of the machine as indicated by an arrow A, the operation lever 16 fits into one of the slits 25 or 26. In the fitted state, the forward or reverse transmission member 17 on the fitted side
Alternatively, the transmission device 9 is driven by rotating the transmission 18 in the front-rear direction. In this case, the operation of the transmission rods 19 and 20 and the link mechanism 21 causes the forward and reverse transmission members 1
7 and 18 move in the opposite directions. For example, when the operation lever 16 is locked to the forward-side transmission member 17 and moved forward as shown by the arrow B, the reverse-side transmission member 18 (To be described later).

Transmission rods 19 and 20 are connected to the forward and reverse transmission members 17 and 18, respectively. These transmission rods 19 and 20 are connected at their lower ends and are connected to a speed change drive link mechanism 21. This connection structure will be described in detail with reference to FIG.

FIG. 4 is a plan view of the control panel 15 and FIG. 5 is an explanatory view of the operation range of the operation lever 16.
As shown in FIG. 4, a guide groove 39 of the operation lever 16 is formed substantially at the center of the control panel 15. As shown in FIG. 5, the guide groove 39 includes a first operation range 39a extending in the left-right direction at the center, a second operation range 39b extending forward from the left end of the first operation range 9a, and a first operation range. 3
9a is formed by a third operation range 39c extending rearward from the right end of 9a. The first operation range 39a at the center is a neutral position. The second operation range 39b is an operation range on the forward side, and the speed is increased in the forward direction as the operation lever 16 moves forward (in a direction away from the neutral position). The third operation range 39c is a reverse operation range, and the operation lever 16
Increases in the reverse direction as it moves backward (in a direction away from the neutral position).

FIG. 6 is a detailed structural view of the operation lever 16 portion. The operation lever 16 is rotatable as indicated by an arrow D about an axis 40 extending in the left-right direction of the machine (perpendicular to the drawing) at the lower end thereof. The forward and reverse transmission members 17 and 18 are also rotatable around the shaft center 40 as indicated by arrows F and G. A transmission rod 19 is pivotally attached to the forward shifting member 17 so as to be rotatable around a shaft 17b. Similarly, the transmission rod 20 is connected to the
It is pivotally connected around b. Transmission rods 17, 18
The shafts 17b and 18b are pivotally mounted on opposite sides of the shaft core 40 with the shaft core 40 interposed therebetween. These transmission rods 19, 20 are rotatably connected at their lower ends via a shaft 27 (FIG. 1).

Accordingly, when the operating lever 16 is engaged with one of the transmission members, for example, the forward-side transmission member 17 and is rotated as shown by the arrow F, the transmission rod 19 is moved substantially in the longitudinal direction as shown by the arrow H. Move up and down along. As a result, the shaft 27 at the lower end rotates around the shaft 29 (FIG. 8) fixed to the machine body via the lever 28 (FIG. 8) as shown by an arrow K (FIG. 8), and the transmission on the reverse side is performed. Arrow 20 with rod J
The transmission rod 1 on the forward side substantially along the longitudinal direction as shown in FIG.
Move up and down in the same direction as 9. The vertical movement of the reverse transmission rod 20 is transmitted to the reverse transmission member 18 via the shaft 18b at the upper end thereof, and the reverse transmission member 18 on the opposite side to the forward transmission member 17 with respect to the shaft 40 moves forward. The rotation operation is performed symmetrically with the side transmission member 17 as shown by the arrow G. As a result, as described with reference to FIG.
a and 18a move in mutually opposite directions. When the operating lever 16 is engaged with one of the locking pieces and is moved, the other locking piece is automatically moved in the opposite direction. Moving.

The operation lever 16 is rotatable about an axis 40 extending in the lateral direction of the machine as described above.
It is rotatable around an axis 24 that extends perpendicular to the axis 40 and extends in a direction intersecting the direction in which the operation lever 16 extends. Thus, the operation lever 16 can move in the left-right direction within the first operation range 39a (FIG. 5) in the neutral position.
The shaft 24 is rotatably fitted around and held in a sleeve 42 fixed to a frame 43 on the body side. The lever 4 is attached to the shaft 24 protruding from the sleeve 42.
5 is fixed. The inner wire 22a of the switching drive wire 22 is attached to the end of the lever 45. Thus, by turning the operation lever 16 right and left at the neutral position, the push-pull operation of the inner wire 22a switches the switching device 10 (FIG. 1) to the forward side or the reverse side as described later.

FIG. 7 is a detailed block diagram of the switching device 10. The end of the inner wire 22a of the switching drive wire 22 is connected to the upper end of the vertical piece 46c of the link lever 46 provided on the upper surface of the switching device 10 and having an L-shape in side view.
The shaft 46b is integrally joined to the lower end of the vertical piece 46c. The shaft portion 46b is rotatably supported on the switching device 10 by the holding plate 56 (see FIG. 9 described later). The end 46a of the shaft 46b contacts the upper end of the switching shaft 47. The switching shaft 47 is always urged upward by a spring 48.
By rotating the operation lever 16 in the lateral direction of the machine, the inner wire 22a performs a push-pull operation as indicated by an arrow P. Thereby, the link lever 46 is
The pivot 46 rotates around the shaft portion 46b through which the holding plate 56 is inserted, and the end 46a rotates as shown by the arrow Q to move the switching shaft 47 upward or downward.

The switching shaft 47 is mounted in the sleeve shaft 54 so as to be slidable up and down. The switching shaft 47 has a large-diameter portion 47a having an outer diameter substantially equal to the inner diameter of the sleeve shaft 54 at a substantially central portion thereof and small-diameter portions 47 formed on both upper and lower sides thereof.
b, 47c. The shaft 5 is located below the sleeve shaft 54.
5 is press-fitted and integrated. A pinion 55a of a bevel gear is provided at the lower end of the shaft 55, and the drive wheel 11
The drive shaft 23 is rotated by meshing with a counterpart bevel gear (not shown) mounted on the drive shaft 23 (FIG. 1).

On the sleeve shaft 54, three balls 49 and 50 (one each in the upper and lower parts in the figure)
(Shown individually) are inserted so as to protrude outward. When the switching shaft 47 moves upward, the large diameter portion 47a pushes the upper ball 49 outward. Conversely, when the switching shaft 47 moves downward, the large-diameter portion 47a moves to the lower ball 50.
Extrude outward.

The upper and lower balls 49, 5 are provided on the sleeve shaft 54.
0, separated from the sleeve shaft 54 (ie, rotatable with respect to the sleeve shaft 54) at two upper and lower positions corresponding to 0.
Bevel gears 52 and 53 are mounted. These bevel gears 52,
The gear 53 meshes with a pinion 51a at an end of a transmission shaft 51 driven from the engine via a transmission, and rotates in mutually opposite directions.

For example, the switching shaft 47 is moved upward by the operation lever via the wire 22 so that the upper ball 4 is moved.
9 is pushed out, the ball 49 is moved to the upper bevel gear 5.
2 and a sleeve shaft 54 and an integral shaft 55
Is integrally connected to the upper bevel gear 52, and the shaft 55 is rotated together with the upper bevel gear 52 in the same direction (for example, the forward direction). Conversely, when the switching shaft 47 is moved downward to push the lower ball 50 outward, the ball 50 engages with the lower bevel gear 53 and the sleeve shaft 54 and the shaft 55 integral therewith. Is integrally connected to the lower bevel gear 53, and the shaft 55 is rotated together with the lower bevel gear 53 in the same direction (reverse direction).

In this manner, the switching device 10 can be switched to the forward side or the reverse side by rotating the operation lever 16 in the left-right direction within the first operation range 39a (FIG. 5) in the neutral position. it can. FIG. 7 shows a state in which the upper and lower balls 49 and 50 are both retracted into the sleeve shaft 54 and are not engaged with any of the upper and lower bevel gears 52 and 53.

FIG. 8 is a configuration diagram of a link mechanism 21 for connecting the operation lever and the transmission 9. FIG. 9 is a plan view of the transmission 9 and the switching device 10, and FIG.
0 is a view on the arrow AA.

As shown in FIG. 8, a shaft 27 for connecting the lower ends of the transmission rods 19 and 20 on the forward side and the reverse side is connected.
Is connected to one end of a shaft 29 via a lever 28.
The shaft 29 is rotatably held on the body frame 30 side.
The upper end of the lever 38 is fixed to the other end of the shaft 29 (see FIG. 2). The link rod 3 is provided at the lower end of the lever 38.
1 is pivoted. The link rod 31 is connected to a driving member 33 via a connection frame 32 made of sheet metal. An opening 37 is formed on a side surface of the connection frame 32. A part of the drive pulley 36 of the transmission 9 projects outward through the opening 37 (see FIGS. 2 and 9). Accordingly, the connection frame 32 can be provided to be closer to the inside of the body, and the entire link mechanism 21 can be compactly housed in the body frame.

The drive member 33 is connected to the right side of a drive frame 34 for operating the transmission 9. This drive frame 3
Reference numeral 4 is attached to an airframe (not shown) so as to be rotatable around an axis 35 as indicated by an arrow R (FIG. 9). In the middle part of the drive frame 34, long holes 58 are formed at two positions above and below the position of the drive shaft 59. In this long hole 58, two upper and lower pressing bolts 5 fixed to the pressing member 62 of the transmission are provided.
7 is movably inserted along the long hole. This allows
The drive frame 34 rotates around the shaft 35 in accordance with a reciprocating operation (arrow R) of the operation lever via the link mechanism 21.
The rotation is transmitted to the drive shaft 59 from the engine via the pulley 5 (see FIG. 1).

The transmission 9 has a drive shaft 59 (FIGS. 2, 9,
The drive pulley 36 is mounted on the drive pulley 36 and the driven pulley 60 is connected to the drive pulley 36 via a V-belt 61 (FIG. 10). The drive pulley 36 includes a pair of conical fixed pulleys 36a and a movable pulley 36b that form a V-shaped groove facing each other. The fixed pulley 36a is connected to the drive shaft 5
9, the movable pulley 36b is slidable on the drive shaft 59 in the axial direction. The movable pulley 36b is pressed and driven by the pressing member 62 connected to the operation lever, and slides on the drive shaft 59. Thereby, the fixed pulley 36a
, The width of the V-groove changes, and the position of the V-belt 61 attached to this V-groove in the pulley radial direction changes. As a result, the gear ratio continuously changes continuously.

The driven pulley 60 comprises a fixed pulley 60a and a movable pulley 60b mounted on the transmission shaft 51. The shift transmission shaft 51 is connected to the switching device 1 as described above.
0 (see FIG. 7). The fixed pulley 60a is fixed to the transmission shaft 51, and the movable pulley 60b is slidable on the transmission shaft 51 in the axial direction. A driving pulley 36 is provided between the fixed pulley 60a and the movable pulley 60b.
A V-groove is formed in the same manner as described above, and the V-belt 61 is wound.
In this case, in the drive pulley 36 and the driven pulley 60, the positions of the fixed pulley and the movable pulley in the axial direction are reversed.
That is, as shown in FIG. 9, in the drive pulley 36, the fixed pulley 36a is arranged on the shaft rear side (left side in the figure), and the movable pulley 36b is arranged on the shaft front side (right side in the figure). On the other hand, in the driven pulley 60, the fixed pulley 60a is disposed on the front side of the shaft (right side in the figure), and the movable pulley 60b is disposed on the rear side of the shaft (left side in the figure). With this arrangement, on the drive pulley 36 side, the V-groove width is reduced by being pressed by the pressing member 62 and the V-belt 61 moves toward the outside of the pulley toward the rear of the shaft along the inclined surface 36c of the fixed pulley 36a. Moving. Correspondingly, on the driven pulley 60 side, the V-belt 61 of a fixed length moves inward. At this time, since the fixed pulley 60a is arranged on the front side of the shaft, V
The belt 61 is driven along the inclined surface 60c by the driving pulley 36.
Move to the same axis rear side as. Thereby, the driving pulley 3
The position of the V groove of the driven pulley 60 is always aligned with the position of the V groove of the driven pulley 60, so that the V belt 61 can transmit rotation without distortion.

The movable pulleys 36b and 60b of the driving pulley 36 and the driven pulley 60 have reaction force damping mechanisms 63, respectively.
Is provided. This reaction force buffering mechanism 63 includes a compression spring 67 provided on the back side of each of the movable pulleys 36b and 60b.
, A spiral inclined guide 64, and a roller 65 rolling on the inclined guide 64. When the movable pulleys 36b and 60b of the continuously variable transmission 9 are driven by the operation lever, the reaction force is transmitted from the movable pulley side to the operation lever via the V-belt. In this case, the reaction force is applied to the roller 65 via the inclined guide 64 together with the spring 67.
, The reaction force is decomposed into component forces in two directions, a radial direction and an axial direction. Therefore, the axial component force acting on the operation lever is reduced. By providing such a reaction damping mechanism 63 on both the driving pulley 36 and the driven pulley 60, the pressing member 62 by the operation lever is provided.
Can be greatly reduced, the operation can be easily performed, the operation feeling can be improved, and the components of the driving means can be reduced in size and weight. In order to enhance the compatibility and versatility of the movable pulley and the fixed pulley constituting the driving pulley and the driven pulley, the inclined guide 64 is provided on the rear side of the fixed pulleys 36a and 60a as well as the movable pulley. ing.

FIGS. 11A and 11B show the structure of the speed change member for further reducing the reaction force to the operation lever. FIG. 11A is a front view and FIG. 11B is a side view. A pin 68 is provided on the forward shifting member 17 and a tension spring 70
Lock one end of A pin 69 is provided on the body frame 71 (FIG. (B)), and the other end of the spring 70 is locked. The spring 70 is disposed at a position that is aligned with the shaft 40 of the transmission members 17 and 18 when the operation lever 16 is in the neutral position (the state shown in the drawing). In this case, it is desirable that the position of the pin 69 on the body frame 71 can be adjusted as indicated by the arrow S. As a configuration for this position adjustment, for example, a long hole (not shown) is provided on the body frame 71 side, and a pin 69 is mounted in the long hole so as to be position-adjustable as shown by an arrow S, and a screw or the like is adjusted at the adjusted position. And the like.

In the neutral position where the spring 70 passes through the shaft core 40, the spring 70 does not apply a tensile force to the transmission member 17. When the operation lever 16 is rotated around the axis 40 and driven in the forward or reverse direction,
The pin 68 rotates, and the position of the spring 70 deviates from the position of the shaft center 40. As a result, the tensile force of the spring 70 acts on the speed change member 17 and urges the speed change member 17 to further rotate in the same driving direction. Therefore, the operation force of the operation lever 16 is reduced against the reaction force from the transmission. As described above, since the forward-side and reverse-side transmission members 17 and 18 are interlocked, the acting force of the spring 70 that resists the reaction force regardless of whether the operation lever 16 is rotated in either the forward side or the reverse side. And the operating force can be reduced. In this case, it is desirable to determine the mounting positions of the pins 68 and 69 so that the tension of the spring 70 increases as the operation amount of the operation lever 16 increases.

In the embodiment described above, the configuration using the V-belt type continuously variable transmission is shown, but the present invention is also applicable to a gear type transmission. Also, the above embodiment is a snow blower, but the present invention is not limited to this,
The present invention is applicable to cultivators, weeders, construction vehicles such as bulldozers and excavators, and other various working machines.

[0040]

As described above, according to the present invention, the forward-side transmission member and the reverse-side transmission member for connecting the operation lever to the transmission mechanism are provided, and these forward-side and reverse-side transmission members are separate members. So that the operation lever is selectively engaged with any one of these, and the moving operation amount of the operation lever is transmitted to the speed change mechanism unit through independent transmission paths on the forward side and the reverse side, respectively. Therefore, for example, by changing the dimensions and mounting positions of the members constituting the transmission path such as the transmission rod between the forward side and the reverse side, the transmission characteristics when transmitting the operation amount of the operation lever to the transmission mechanism can be improved. The forward side and the reverse side are independent of each other, and can be set arbitrarily and set under optimum conditions.

When a transmission such as a gear transmission or an automatic V-belt transmission is used, the transmission or the switching device moves forward and backward in the switching operation of forward high speed → forward low speed → neutral position → reverse low speed → reverse high speed. Even in the case of reciprocating operation at the time of switching, the operation lever can be configured with a simple structure of forward / reverse switching and speed change by one-way forward operation from one side to the other side.

[Brief description of the drawings]

FIG. 1 is a main part configuration diagram of an entire snowplow according to an embodiment of the present invention as viewed from a side.

FIG. 2 is a configuration diagram of the snow blower of FIG. 1 as viewed from behind.

FIG. 3 is a perspective view of an operation lever base of the snow blower of FIG. 1;

FIG. 4 is a plan view of a control panel portion of the snow blower of FIG. 1;

FIG. 5 is an explanatory view of a guide groove for an operation lever of the control panel of FIG. 4;

FIG. 6 is an explanatory diagram of a configuration and an operation of a transmission member of the snow blower of FIG. 1;

FIG. 7 is a configuration diagram of a switching device of the snow blower of FIG. 1;

FIG. 8 is a side view of a link mechanism of the transmission of the snow blower of FIG. 1;

FIG. 9 is a plan view of a transmission and a switching device of the snowplow of FIG. 1;

FIG. 10 is a view in the direction of arrows AA in FIG. 9;

FIG. 11 is a configuration explanatory view showing an example of a reaction force reducing structure of the snow blower in FIG. 1;

[Explanation of symbols]

1: Snow remover, 2: Body pulley, 3: Snow pulley, 4: Belt, 5: Drive pulley, 6: Belt, 7: Snow pulley, 8: Discharge port, 9: Continuously variable transmission, 1
0: forward / reverse switching device, 11: drive wheel, 12: truck, 13: driven wheel, 14: handle, 15: control panel, 16: operation lever, 16a: gripping part, 17: forward-side transmission member, 17a, 18a : Locking pieces, 17b, 18b:
Shaft, 18: reverse-side transmission member, 19, 20: transmission rod,
21: Link mechanism, 22: Switching drive wire, 22a:
Inner wire, 23: drive shaft, 24: shaft, 25, 2
6: slit, 27: shaft, 28: lever, 29: shaft, 3
0: body frame, 31: link rod, 32: connection frame, 33: drive member, 34: drive frame, 35: shaft, 36:
Driving pulley, 36a: fixed pulley, 36b: movable pulley, 37: opening, 38: lever, 39: guide groove, 39
a: first operation range, 39b: second operation range, 39c: third operation range, 40: shaft center, 42: sleeve, 43: frame, 45: lever, 46: link lever, 46a: end, 46b: Shaft, 46c: vertical piece, 47: switching axis, 4
7a: large diameter portion, 47b, 47c: small diameter portion, 48: spring, 49, 50: ball, 51: transmission shaft, 51
a: pinion, 52, 53: bevel gear, 54: sleeve shaft, 55: shaft, 55a: pinion, 56: holding plate, 5
7: pressing bolt, 58: slot, 59: drive shaft, 60: driven pulley, 60a: fixed pulley, 60b: movable pulley,
60c: inclined surface, 61: V-belt, 63: reaction force buffering mechanism, 64: inclined guide, 65: roller, 67: compression spring, 68, 69: pin, 70: tension spring,
71: Airframe

Claims (2)

[Claims] An operating lever for switching between forward and backward movement and shifting;
A traveling drive unit that constitutes a forward / backward switching and speed change mechanism connected to the operation lever; and a grip portion of the operation lever includes: (a): the traveling drive unit of a working machine that is operated to move in a lateral direction of a machine body. To switch between forward and reverse
Operation range, (b): moving the grip portion of the operation lever from one end of the first operation range to one side substantially orthogonal to the first operation range, and moving away from the first operation range according to the amount of movement. A second operating range in which the forward speed of the working machine is increased or decreased so as to increase the forward speed, and (c): an operating lever extending from the other end of the first operating range to the other side substantially orthogonal to the first operating range. A third operation range in which the reverse speed of the working machine is increased or decreased so as to increase the reverse speed as the distance from the first operation range increases, in accordance with the amount of movement of the grip portion. A forward / backward switching mechanism of the machine, wherein an operating lever is engaged with a forward shifting member by moving a grip portion to a second operation range side of the first operation range; and a third operation range of the first operation range Grip on the side After the operation lever is moved, the operation lever is engaged with the reverse-side transmission member.After the operation lever is engaged with the forward-side or reverse-side transmission member, while maintaining the engagement, 2
Alternatively, by moving within the third operation range,
The amount of movement of the grip portion is transmitted to the transmission mechanism of the traveling drive device via transmission means connected to each transmission member through independent transmission paths in the second operation range and the third operation range. A forward / backward switching mechanism for a working machine. 2. The forward-side and reverse-side transmission members are rotatable about one axis extending in the lateral direction of the machine, and the operation lever is rotated about another axis substantially coaxial with the axis. 2. The forward / backward switching mechanism for a working machine according to claim 1, wherein the mechanism is rotatable and rotatable about another axis extending in a direction substantially perpendicular to the axis.