JP2560439Y2 - Forward / backward switching device for agricultural work machine - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an agricultural work machine such as a garden tractor.
The present invention relates to a device for switching the traveling direction between forward and backward.

[Conventional technology]

As a switching means for switching the traveling direction of the agricultural working machine between forward and backward by operating the lever, a prior art Japanese Utility Model Publication No. 53-105229 discloses a method of switching between an engine and a transmission. A counter box having a forward rotation shaft for forward rotation of the power from the engine and a reverse rotation shaft for reverse rotation is provided, and a forward belt is wound around a pulley between the forward rotation shaft and the input of the transmission, Wrap the reversing belt between the pulley between the reverse rotation shaft and the input of the transmission,
The work pulley is wound around the other pulley of the positive rotation shaft and the pulley of the input shaft to the work unit, and the respective belts are tensioned by three tension pulleys to transmit power,
The transmission is cut off when it is loosened, and the three tension pulleys are simultaneously turned by one operating lever, so that the power of the working unit is turned on when moving forward and the power is turned off when moving backward. Is disclosed.

[Problems to be solved by the invention]

However, in order to rotate the three tension pulleys simultaneously with one operation lever to execute the predetermined operation, the arrangement relationship of the three belts, the arrangement relationship of the tension pulleys, and the operation lever The relationship between the rotation angles and the like must be extremely limited, so that there is a problem that the forward / backward switching operation device becomes large.

An object of the present invention is to provide a forward / backward switching device that solves the above-mentioned problems.

[Means for solving the problem]

In order to achieve this object, the present invention provides a belt transmission unit that transmits power from an engine mounted on the body of an agricultural work machine to a traveling unit, a tension arm that switches between forward and backward movement of the body, and a sub swing arm. PT from the belt transmission
While the working unit clutch is provided in the middle of the O-axis, one operating lever and a horizontal axis are provided on a bracket provided on the outer periphery of a cylindrical body rotatably fitted on the horizontal axis. When the operating lever is rotated in the front-rear direction by connecting one operating lever to the pin in a direction perpendicular to the axis, and rotating the operating lever in the front-rear direction, the horizontal axis is rotated around the axis. Only the operation lever is connected so as to be rotatable in the left-right direction on the outer peripheral side of the first rotation lever. The moving plate and the tension arm and the working unit clutch are connected, the second turning plate and the sub-oscillating arm are connected, and the two turning plates are connected to each other according to the selection of the front and rear turning of the operation lever. A selecting means for selectively rotating the first rotating plate and the second rotating plate; Operate the operating lever in the left and right direction during the swinging rotation range in which the operation lever is operated from the vehicle forward side to the reverse side so that the power transmission to the PTO shaft is switched from on to off before switching to the vehicle rearward direction. It has a section to be moved.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings.
In the drawing, reference numeral 1 denotes a walking type agricultural work machine provided with a vehicle body 3 supported by a pair of left and right wheels 2. The vehicle body 3 incorporates an engine 4 in a front part and a transmission mechanism in a rear part. A transmission case 6 having a PTO shaft 5 protruding from a side surface is provided, and power from the engine 4 is transmitted to an axle 8 via a traveling transmission and a chain transmission mechanism 7, while a transmission case 6 is provided on an upper surface of the transmission case 6 in a rearward direction. A pair of left and right steering handles 9 are provided.

Further, a hitch 10 for connecting various working machines is provided at a rear portion of the vehicle body 3, and a rotary cultivator 11 as an example of a working machine is detachably connected to the hitch 10, 11, the power from the PTO shaft 5 is transmitted via chain transmission mechanisms 12 and 13. Reference numeral 14 denotes the engine 4
Reference numeral 15 denotes a driven shaft protruding from a side surface of the transmission case 6 in a direction parallel to the drive shaft 14, and a drive pulley fixed to the drive shaft 14.
16 and a main pulley 17 fixed to the driven shaft 15 and a main endless belt.
It is assumed that both shafts 14 and 15 are rotated in the same direction by winding 18 in parallel.

Reference numeral 19 denotes a sub-pulley to be attached to the drive shaft 14.
Are fixed with screws 21 and 22 via a disc-shaped mounting member 20.

Reference numeral 23 denotes a sub-oscillating arm that is rotatably mounted on the sub-pulley 19 via a bearing 24 and a pivot 25.
A sub-endless belt 28 is wound around an intermediate pulley 27 rotatably supported on a tip shaft 26 and the sub-pulley 19 in parallel. Reference numeral 29 denotes a drum fixed to the driven shaft 15 by bolts 30 adjacent to the main pulley 17, and the outer periphery of the intermediate pulley 27 on the tip side thereof approaches the outer peripheral surface of the drum 29 by the rotation of the sub-oscillating arm 23. At this time, the outer peripheral surface of the sub-endless belt 28 is pressed against the outer peripheral surface of the drum 29 to transmit power.

Reference numeral 31 denotes a tension arm to which a tension roller 32 to be brought into contact with the outer periphery of the main endless belt 18 is attached via a shaft 33, and a base end side of the tension arm 31 and a distal end side of the sub swing arm 23 extend. The tension arm 31 extends in substantially the same direction as the direction, and pivotally supports a middle part of the tension arm 31 on a support shaft 34 projecting from the vehicle body such as the traveling transmission case 6.

Reference numeral 35 denotes the tip side of the sub swing arm 23 and the tension arm.
The link mechanism that connects the base end of the
A first link piece 36 rotatably attached to the distal end shaft 26 of the 23, and a second link piece 36 rotatably attached to the first link piece 36 via the connecting shaft 37.
The second link piece 38 is provided with a vertically long guide groove 39, and an engagement pin 40 projecting from the base end side of the tension arm 31 is slidable in the guide groove 39. Is fitted.

Reference numeral 41 denotes a first wire connected to one end for rotating the tension arm 31, and reference numeral 42 denotes a second wire connected to one end to the first link piece 36, and an operation lever 43 provided on the operation handle 9. By operating this, the first wire 41 or the second wire 42 is selectively pulled to switch between the forward and backward movements of the agricultural machine described below.

That is, when the first wire 41 is pulled, the tension arm 31 is rotated to cause the tension roller 32 to rotate the main endless belt 18.
Press the outer peripheral surface on the loose side. At this time, the engagement pin 40 on the base end side of the tension arm 31 is fitted into the vertically long guide groove 39 of the second link piece 38 and pushes the second link piece 38 downward, so that the first link piece 36 is The outer end of the intermediate pulley 27 is separated from the outer periphery of the drum 29, and the auxiliary swing arm 23 is interlocked with the outer periphery of the drum 29 so that the contact between the sub endless belt 28 and the outer periphery of the drum 29 is released ( The driven shaft 15 rotates in the same direction as the drive shaft 14, and the agricultural work machine 1 moves forward (see the two-dot chain line in FIG. 3).

On the contrary, when the second wire 42 is pulled, the sub swing arm
The outer periphery of the intermediate pulley 27 attached to the tip of the sub-oscillating arm 23 approaches the outer periphery of the drum 29, and the outer surface of the sub endless belt 28 at the outer periphery of the intermediate pulley 27 is driven. Since the driven shaft 15 is pressed against the outer peripheral surface of the drum 29 fixed to the shaft 15, the rotation direction of the driven shaft 15 is opposite to that of the drive shaft 14, while the guide groove 39 and the engagement pin 40 of the second link piece 38 are provided.
The base end side of the tension arm 31 is rotated upward through the tension arm 32 to be attached to the tension arm 31.
Tension arm 31 so that the
Work together.

A cover A covers the entire drive pulley to the main pulley together with the link mechanism.

The operation lever 43 is a case 44 fixed to the operation handle 9.
(F direction and B direction) through a cylindrical body 50 fitted on the horizontal shaft 45 fixed to the cylindrical body 51, and a bracket 51 and a pin 52 attached to the cylindrical body 51.
Direction) and rotatable left and right (L and R directions). The operation lever 43 is turned upward from a substantially Z-shaped guide hole 46 formed in a top surface of the case 44 in a plan view. To protrude.

On the other hand, a first rotary plate 47 and a second rotary plate 48 are rotatably fitted on the horizontal shaft 45 on both sides of the operation lever 43, respectively.
A pin 47a that can contact the front surface of the operation lever 43 is provided on the upper end of the rotation plate 47, and a pin 48a that can contact the rear surface of the operation lever 43 is provided on the upper end of the second rotation plate 48. When the operating lever 43 is turned forward, only the first turning plate 47 can be turned, and when the operating lever 43 turns backward, only the second turning plate 48 can be turned. Selection means.

The other end of the first wire 41 is connected to the lower end of the first rotating plate 47, and the other end of the second wire 42 is connected to the lower end of the second rotating plate 48. The two wires 41 and 42 are selectively pulled by the rotation operation.

At the lower end of the second rotary plate 48, a wire 49 for disconnecting and operating a working unit clutch 53 (having a conventionally well-known structure) provided on the PTO shaft 5 is connected, and the operation lever 43 is connected. The working unit clutch 53 with respect to the PTO shaft 5 is configured to be turned on and off by the forward and backward tilting. In this case, as shown in FIG. 12, a substantially halfway position of the rear half of the Z-shaped guide hole 46 is provided. When the operation lever 43 is located at the position, the tension roller 32 is separated from the main endless belt 18 and the outer surface of the sub endless belt 28 on the outer periphery of the intermediate pulley 27 is separated from the outer peripheral surface of the drum 29, that is, it does not advance or retreat. Neutral position. When the vehicle is further inclined backward in the direction B, the outer surface of the sub-endless belt 28 on the outer periphery of the intermediate pulley 27 is pressed against the outer periphery of the drum 29, and the driven shaft 15 rotates in the reverse direction, so that the vehicle body moves backward.

When the operation lever 43 is rotated in the forward direction (F direction) from the neutral position, the tension roller 32 is rotated by the main endless belt due to the relationship between the play guide groove 39 and the engagement pin 40 in the link mechanism 35. Although it is pressed against the outer peripheral surface of 18, in the middle of the guide hole 46, once the operation lever 43 is not rotated in the left and right direction, a section where further forward and backward movement is not possible is provided, as shown in FIG. During the swinging rotation range in which the operation lever 43 is operated from the vehicle forward side to the backward side (during the forward section)
Further, a section is provided for turning the operation lever 43 in the left-right direction so that the power transmission to the PTO shaft is switched from on to off before switching to the backward movement of the vehicle body.

In this way, when the operating lever 43 is pivoted in the retreating direction (direction B), power transmission to the working unit is shut off before the retraction of the vehicle body is started, which is safe. Power transmission to the working unit can be shut off even during forward movement.

If the operation lever 43 is biased to rotate in the direction F from the neutral position, the operation lever 43 is rotated in the direction B to slightly retract the vehicle body, and then the hand is released from the operation lever 43. Then, the operation lever 43 can be tilted forward so as to automatically advance.

FIG. 6 shows that a flat band annular friction material 60 having a large friction coefficient is adhered and fixed to the outer peripheral surface of the drum 29, and the outer peripheral surface of the sub-endless belt 28 is brought into contact with the friction material 60. Communication can be ensured.

FIG. 7 shows a case where the cross section of the sub-endless belt 51 wound around the sub-pulley 19 and the intermediate pulley 27 is formed in a hexagonal shape. In this case, the sub-endless belt 51 is attached to the outer peripheral surface of the drum 52 attached to the driven shaft 15. By forming the substantially V-shaped groove 53 so that the outer peripheral surface of the endless belt 51 contacts in a wide range, power transmission can be ensured.

FIG. 8 shows an embodiment not directly related to the present invention, in which a sub-endless belt 5 is provided between two intermediate pulleys 54 and 54 and a sub-pulley 19.
5, a supporting member 57 is slidably configured to press the outer peripheral surface of the sub-endless belt 55 located on the outer periphery of the two intermediate pulleys 54, 54 toward the outer periphery of the drum 56. A state in which the pair of intermediate pulleys 54 approaches the drum 56 to rotate the driven shaft 15 in the reverse direction with respect to the drive shaft 14;
If the power can be switched from 16 to the main pulley 19 via the main endless belt 18 to rotate the main pulley 19 in the same direction, the outer peripheral surface of the sub endless belt 55 contacts over a wide range on the outer peripheral surface of the drum 56. Therefore, in the case of the reverse rotation, the power transmission can be reliably performed.

[Effect of the invention]

As described above, according to the present invention, the tension transmitting arm and the sub-oscillating arm for switching between forward and backward movement of the vehicle body are provided in the belt transmission section for transmitting the power from the engine mounted on the vehicle body of the agricultural work machine to the traveling section. , PTO from the belt transmission
A working unit clutch is provided in the middle of the shaft, and a pin is attached to a bracket provided on the outer periphery of a cylindrical body in which one operating lever and a horizontal shaft are rotatably fitted on the horizontal shaft. When the operation lever is rotated in the front-rear direction by rotating the operation lever in the front-rear direction by rotating the operation shaft in the front-rear direction, the horizontal axis is rotated around its axis. The first rotation of the two rotation plates which are connected so that only the operation lever is rotatable in the left-right direction on the outer peripheral side, and are rotatably supported on a horizontal axis with the one operation lever interposed therebetween. Connecting the plate, the tension arm and the working unit clutch,
A second pivoting plate and a sub-oscillating arm are connected, and the first pivoting plate and the second pivoting plate are selected as the two pivoting plates in accordance with a selection of the forward / backward rotation of the operation lever. Is provided with a selection means for rotating the main body, so that the sub-oscillation arm for retreating the vehicle body and the tension roller for forward movement are linked by one operating lever, and work is performed only during forward movement. Switching work can be performed so as to turn on the part clutch, and operation of the agricultural work machine can be extremely simplified.

Then, only the first turning plate is turned by turning the operating lever in the forward direction to turn on the forward and the working unit clutch, and only the second turning plate is turned when the other operating lever is turned backward. The two rotating plates are selectively rotated by the forward and backward rotation of the operation lever so that the operating lever is moved backward.
In addition, during the swing range in which the operating lever is operated from the vehicle forward side to the reverse side, the operating lever is moved in the left-right direction so that the power transmission to the PTO shaft is switched from on to off before switching to the backward movement of the vehicle body. Since the rotating section is provided, the conventional three tension pulleys are simultaneously rotated by one operating lever to perform the predetermined operation. It is not necessary to set the arrangement relationship of the tension pulley and the rotation angle relationship of the operation lever, etc., and the forward / backward switching operation device of the operation lever, the horizontal shaft and the two rotation plates provided at both ends thereof is provided at an appropriate position. This has the effect of being compact and compact.

[Brief description of the drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a side view of an agricultural working machine, FIG. 2 is a plan view, FIG. 3 is an enlarged side view of a main part, and FIG. 4 is an IV-IV output cross section of FIG. FIG. 5 is a perspective view of a link mechanism, FIG. 6 is a cross-sectional view of another embodiment of a drum portion, and FIG.
Fig. 8 is a sectional view showing another embodiment of the sub-endless belt, Fig. 8 is a schematic side view of another embodiment, Fig. 9 is a perspective view showing attachment of a lever, Figs. FIG. 12 is an explanatory view of a guide hole. 1 ... agricultural working machine, 2 ... wheels, 3 ... body, 4 ... engine, 5 ... PTO shaft, 6 ... mission case, 9 ...
Steering handle, 14 ... Drive shaft, 15 ... Driven shaft, 16 ... Drive pulley, 17 ... Main pulley, 18 ... Main endless belt, 23 ...
… Sub-oscillation arm, 27 …… Intermediate pulley, 28,51 …… Sub-endless belt, 29,52 …… Drum, 35 …… Link mechanism, 43 ……
Operation lever, 46: guide hole, 47: first rotating plate, 47a,
48a: Pin, 48: Second rotating plate, 60: Friction material.

Claims (1)

(57) [Scope of request for utility model registration] 1. A belt transmission unit for transmitting power from an engine mounted on a vehicle body of an agricultural work machine to a traveling unit is provided with a tension arm for switching between forward and backward movement of the vehicle body and a sub-oscillation arm. While the working unit clutch is provided in the middle of the PTO shaft, one operating lever and the horizontal shaft
A pin is arranged in a direction perpendicular to the axis of the horizontal shaft on a bracket provided on the outer periphery of the cylindrical body rotatably fitted on the horizontal shaft, and one operation lever is connected to the pin so as to be rotatable left and right. When the operation lever is rotated in the front-rear direction, the horizontal shaft is rotated around its axis, and only the operation lever is connected to the outer peripheral side of the horizontal shaft so as to be rotatable in the left-right direction. 2 rotatably supported on a horizontal axis with the operation lever of
A first rotating plate of the two rotating plates is connected to the tension arm and the working unit clutch, a second rotating plate is connected to the sub-oscillating arm, and both of the rotating plates are provided with an operation lever. Selecting means for selectively rotating the first rotating plate and the second rotating plate in accordance with the selection of forward and backward rotation of the vehicle, and operating the operation lever from the vehicle body forward side to the backward side. Agricultural work in which a section for turning the operation lever in the left-right direction so that power transmission to the PTO shaft is switched from on to off before switching to the backward movement of the vehicle body in the swing rotation range. Forward / backward switching device in the machine.