JPH0637459Y2 - Speed change operation device in agricultural work machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to the structure of an operating device for a transmission in an agricultural work machine or the like.

[Conventional technology and problems to be solved]

When transmitting power from a drive shaft such as an engine in a farming machine such as a rice transplanter or a tractor to a driven shaft such as a mission case, the driven shaft is switched between high speed and low speed,
As a means for connecting and disconnecting power to the driven shaft, in a mission case incorporating a conventionally known gear type speed change mechanism, a clutch for connecting and disconnecting power is generally provided between the engine and the mission case or in the mission case. Even in the gear shifting operation in this mission case, it is normal to operate the gear shifting operation lever with the clutch temporarily turned off, and it requires two operating systems: clutch ON / OFF and gear shifting operation. Yes, shifting operation is troublesome,
There was also the problem that the structure became complicated.

As means for solving this problem, there is a so-called double tension method disclosed in Japanese Utility Model Publication No. 53-50381 and Japanese Utility Model Publication No. 62-36650.

That is, a high-speed belt and a low-speed belt are wound around the drive shaft and the driven shaft in two rows, and a rotating arm having a tension roller at its tip is attached to each belt. One operating lever and each of the above-mentioned rotations are provided so that the moving arms can be respectively rotated so that the two belts are not tensioned, the high-speed belt is tensioned, and the low-speed belt is tensioned. According to this configuration, when the speed is switched from low speed to high speed, or when switching to the opposite direction, the two rotating belts are temporarily not tensioned and then one of the rotation arms is tensioned. As the belt tension clutch is turned on and off, there is little shock itself when turning the belt tension clutch on and off, but during gear shifting operations, the state in which power transmission to the driven shaft is once turned off is turned on. Because switched on, the switching shock occurs in relation to the load of the driven shaft side during, there is a problem that can not be smooth shifting.

In order to eliminate this inconvenience, the present applicant has previously filed an application 60
-23027, by rotating one operating lever in a straight line, one operating lever and a rotating arm of a tension roller for tensioning the endless belt are rotated in one direction. For switching the power transmission to OFF, and interlockingly connecting via the first connecting body so as to turn ON the power transmission when rotating in the other direction, while switching the operating lever and the speed change mechanism to high or low. When the operation shaft is interlocked via the second connecting body and the power transmission is turned on, the operation shaft is positioned on the low speed side, and the operation lever is further rotated in the other direction, It has been proposed that the operating shaft is configured to rotate to the high speed side.

In this structure, a clutch cam plate and a gear shift cam plate that are rotatable about their respective proximal end pivots are arranged side by side, and the first connecting body and the second connecting body are provided at one end of each cam plate. A support bracket provided with a rotator that is connected to each other and engages and disengages with the end surface cam portion of each cam plate is provided so as to rotate integrally with the rotation of the operation lever. The rotation phase angle between the child and the end face cam portions of the two cam plates is deviated so as to be displaced.

By the way, in this prior application (see the specification and drawings of Japanese Patent Application No. 60-23027), when the clutch petal is pushed down, the clutch for transmitting the power is disengaged so that it is connected to the rotating arm of the tension roller. Although it is connected to the base of the clutch petal via, even if this petal operation is performed,
Since the operation lever has no biasing means (spring or the like) for restoring the posture to the neutral position side, the rotational position of the operation lever does not change. Therefore, when the clutch lever is released again with the operating lever in the high speed position, the operation such as high speed running is suddenly started, the engine load increases, and the engine stops.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a gear shift operation device in an agricultural work machine in which the operability of the operation lever is improved.

[Means for Solving the Problems]

For this reason, the present invention provides a speed change device configured to transmit power to an input shaft to the mission case via an endless belt while providing a speed change mechanism for switching between high speed and low speed in a mission case mounted on an agricultural work machine. In, a single operation lever can be held in at least three positions from one direction to the other direction via a locking rotator that rotates integrally with the operation lever and a detent fitting that engages with and disengages from the operation lever. And a rotation arm of a tension roller for tensioning the endless belt, the first connection body and the swing arm. By interlockingly connecting via a biasing spring, the trochanter in the swing arm and the cam part of the cam plate that rotates integrally with the operation lever can be engaged and disengaged to rotate the operation lever in one direction. Power transmission to OFF , O power transmission in rotation in the other direction
On the other hand, the cam plate of the operation lever and the operation shaft for switching the transmission mechanism between high and low are interlockingly connected via the second connecting body while the power transmission is performed.
In the ON state, the operating shaft is positioned on the low speed side, and when the operating lever is further rotated in the other direction, the operating shaft is rotated on the high speed side so that An engagement / disengagement phase with the cam portion of the cam plate is set, the clutch petal and the detent metal fitting are wire-connected, and the engagement with the locking trochanter is released by pressing down the clutch petal to operate the operation lever. Is configured so that the rotational posture of the at least returns to the low speed side.

[Function and effect of device]

In this way, one operation lever is positioned at at least three positions from one direction to the other direction through the locking rotator that rotates integrally with the operation lever and the detent fitting that engages with and disengages from the operation lever. A swinging arm configured to be rotatable so as to be held, and swingable coaxially with a rotation fulcrum of the detent fitting,
A tension roller rotating arm for tensioning the endless belt is interlockingly connected via a first connecting body and an urging spring, and a trochanter in the swinging arm and a cam plate that rotates integrally with the operation lever. By engaging and disengaging with the cam part, the power transmission is turned off by turning the operation lever in one direction, and the power transmission is turned on by turning in the other direction. A cam plate of the lever and an operation shaft for switching the transmission mechanism between high and low, interlockingly linked via a first connecting body, and with the power transmission turned on, position the operation shaft on the low speed side; When the operation lever is further rotated in the other direction, the operation shaft is rotated to a high speed side,
Since the engagement / disengagement phase between the trochanter of the swing arm and the cam portion of the cam plate is set, in order to start driving the farm work machine from the stopped state, be sure to pass the low speed stage from the neutral position where power transmission is OFF. Since the vehicle shifts to the high speed, the shifting work can be smoothly and naturally executed without suddenly shifting from the stopped state to the high speed.

Also, during a gear shift operation between the low gear and the high gear by the operation lever, it is possible to shift to either the high gear or the low gear without passing through the neutral position (the clutch OFF position).
In other words, since the gear shift operation can be performed while power is being transmitted, shock is less likely to occur when the power transmission from the transmission case to the load side is changed.

Then, since the clutch petal and the detent metal fitting are wire-connected and configured to release the engagement with the locking trochanter by pressing the clutch petal, power transmission is once performed by pressing the clutch petal. If the foot is released from the clutch petal to transmit power again after the cutoff, the rotating posture of the operating lever returns to at least the low speed side, so there is no danger of suddenly running at high speed, and the engine is not overloaded. This has the remarkable effect that the gear shifting operation becomes extremely easy without giving the change.

〔Example〕

An embodiment in which the present invention is applied to a rice transplanter will be described below. In the figure, a traveling machine body 1 of the rice transplanter includes a front frame 3 having an engine 2 mounted thereon, a mission case 4 connected to the rear portion thereof, and a front view gate. It is composed of a mold frame 5 and upper and lower left and right sides of the gate frame 5 and upper and lower frames 6 and 7 connected to the side surfaces of the mission case 4, and the front wheels 8 and 8 are attached to the side of the mission case 4 and rear. The wheels 9 and 9 are gearboxes 10 and 10 provided on the lower left and right sides of the gate frame 5, respectively.
Attach to.

The power of the rear wheels 9 and 9 is transmitted via transmission shafts 11 and 11 extending to the side of the transmission case 4 and the outer surface of the lower frame 7 to a gear box 10, and the front wheels 8 and 8 are also transmitted to the transmission case 4. It is driven via an internal speed change mechanism (not shown).

Reference numeral 12 is a seedling planting device that can be moved up and down largely via a parallel link mechanism 13 at the rear of the traveling machine body 1.
The plurality of planted transmission cases 15 on the bottom surface of which the float 14 is disposed, a seedling planting mechanism 16 that rotates up and down laterally of each planted transmission case 15, and a seedling mounting table 17, The seedling planting device 12 can be largely moved up and down through a hydraulic cylinder 18 having a lower end attached to the rear end of the mission case and a lift arm 19 having a triangular shape in a side view.

On the upper surface of the machine body 1, a steering handle 23 for a steering shaft inserted in the steering column 22 is attached to an upper end of a steering column 22 standing upright behind the engine 2, and a turning operation of the steering handle 23 is performed. Due to
It is configured to steer both front wheels 8,8,
A seat 24 is provided at a rear position of the steering handle 23 on a top surface of a cover body 25 that covers the gate-shaped frame 5 to the mission case 4.

The power of the engine 2 in the front part of the traveling vehicle body 1 is transmitted to the mission case 4 via an endless belt 20 such as a belt, and then from the mission case 4, the front wheels 8 and 8 and the rear wheels 9 and 9 are transmitted. The vehicle is configured to travel by transmitting power to the seedling planting device 12 via the PTO shaft 21.

An operation lever 26, which is disposed so as to be rotatable forward and backward on the side of the steering column 22, connects and disconnects power from the engine 2 to the transmission mechanism in the transmission case 4 by the endless belt 20 via an interlocking mechanism 27 described in detail later. The operation and the transmission mechanism (not shown) in the mission case 4 are operated.

That is, the endless belt 20 is wound around the pulley 29 of the output shaft 28 on the side surface of the engine 2 and the pulley 31 of the input shaft 30 on the side surface of the mission case 4, and is pivotally attached to the side surface of the mission case 4 so as to be vertically rotatable. Tension roller 33 at the tip of rotating arm 32
Is arranged between the shafts 28 and 30 so as to be pressed against the outer surface of the endless belt 20.

Reference numeral 34 is a first connecting body in which a middle portion is formed in a coil-shaped spring portion 35, one end of the first connecting body 34 is pivotally attached to the rotating arm 32, and the other end of the first connecting body 34 is A swing arm 38 is pivotally supported at its base end on a support shaft 37 between the frames 36, 36 'so that its length is adjustable.

The cam plate 39 whose end face is always in contact with the trochanter 40 provided in the middle of the swing arm 39 is fixed to the rotary support shaft 41 so as to rotate integrally with the operating lever 26. In the convex portion of the end face cam portion of the plate 39, the operation lever 26 is provided with the traveling body 1
When it is rotated in the front direction of the rocking arm 38, the rocking arm 38 is rocked in the direction away from the endless belt 20 at the low speed position (L) and the high speed position (H) rotated further forward. The rotating arm 32 is pulled through the first connecting body 34 attached to 38, and the tension roller 33 tensions the endless belt 20.

On the contrary, at the neutral position (N) in which the operation lever 26 is rotated to the rear of the traveling machine body 1, the trochanter 40 falls into the recess 42 in the end cam portion of the cam plate 39 and is mounted via the swing arm 38. The rotating arm 32 is rotated by the first connecting body 34 so that the endless belt 20 is in a relaxed state (see FIG. 3).

The inner wire 4 slidably mounted on the outer sleeve 46a of the second connecting body 46 is attached to the engaging pin 45 at the end of the arm portion 44 that rotates integrally with the operation lever 26 and the cam plate 39.
An arm fixed to an operation shaft 49 protruding from the outer surface of the mission case 4 by engaging a link 48 with a long groove 47 attached to one end of 6b, and the other end of the inner wire 46b in the second connecting body 46.
It is connected to 50.

A transmission mechanism (not shown) for sub-transmission, which switches between the high speed side and the low speed side by the rotation of the operation shaft 49, is built in the mission case 4. This transmission mechanism is a conventionally known one-way clutch. A normally meshed gear type speed change mechanism or the like is used, and reference numeral 51 is an urging spring that constantly urges the arm 50 to the low speed side.

Reference numeral 52 designates a detent fitting whose pivotal end is rotatably supported by the support shaft 37, and the tip of the detent fitting 52 has a swing arm 38.
Is arranged so as to extend in the same direction as the detent metal fitting 52
A plurality of recessed grooves 54 are formed at appropriate intervals on the lower surface of the cam plate 39 to engage with the locking rotator 53 projecting from the portion that rotates integrally with the operation lever 26. 52
The operation lever 26 can be held in position while being rotated in each of the (N) position, the (L) position and the (H) position against the force of the spring 55 attached thereto.

Reference numeral 56 is a wire for detent release, one end of the wire 56 is attached to the detent metal fitting 52, and the other end of the wire 56 is a foot petal 57 with a return spring 59 for a clutch or brake device (not shown). It is connected to the arm 58 and the like.

Therefore, when the wire 56 is pulled against the force of the spring 55 by the stepping on of the foot petal 57, the engagement between the locking rotator 53 in the cam plate 39 and the like and the recessed groove 54 of the detent fitting 52 is released, and the operating lever 26 Is configured to automatically return to the direction biased by the force of the springs 35 and 51 [(H) position to (L) position or (L) position to (N) position]. is there.

With this structure, as shown in FIG. 3, when the upper end of the operation lever 26 is rotated from the (L) position to the (N) position,
The trochanter 40 of the swing arm 32 is fitted in the recess 42 on the end face of the cam plate 39 that rotates integrally with the operation lever 26.

Therefore, in the (N) position, the rotating arm 32 with the tension roller 33 is separated via the first connecting body 35 connected to the swinging arm 32 so as to loosen the endless belt 20 (see the chain double-dashed line), and the mission Power transmission to the driven shaft 30 of case 4 is OF
While becoming F, the engagement pin 45 of the arm portion 44 also becomes the second connecting body 46.
The inner wire 46b is moved in the long groove 47 of the link 48 (see the chain double-dashed line), and the urging spring 51 force of the arm 50 causes the operation shaft 49 of the mission case 4 to rotate to the low speed side.

On the contrary, when the operating lever 26 is positioned at the low speed position (L), as shown by the solid line in FIG. 3, the protrusion 40 on the end surface of the cam plate 39 pushes up the trochanter 40, and the swing arm 32 is used. As a result, the first connecting body 34 is pulled, and the tension roller 33 of the rotating arm 32 presses the endless belt 20 so that the endless belt 20 is tensioned, so that the power from the engine 2 can be transmitted to the transmission mechanism in the mission case 4. On the other hand, the engagement pin 45 of the arm 44 is only located near the upper end of the long groove 47 in the link 48 of the second connecting body 46, and the inner wire 46b is not pulled, and the operation shaft 49 of the mission case 4 is held at the low speed position. To do.

Therefore, when the operation lever 26 is rotated from the (N) position to the (L) position, the output shaft from the transmission case 4 can obtain a low-speed rotation output from the stopped state.

When the operating lever 26 is rotated from the (L) position to the (H) position, the trochanter 40 is on the convex portion of the end face of the cam plate 39, which is the first connecting body 34 at the (L) position. Since it is the same as the state of No. 2, from engine 2 to mission case 4
Power transmission continues inside. Then, as shown by the alternate long and short dash line in FIG.
44 The inner wire 46 of the second connector 46 is engaged with the engaging pin 45 at the tip.
A shift operation of pulling b and rotating the operation shaft 49 of the mission case 4 to the high speed side is executed.

When returning from the (H) position to the (L) position or returning from the (L) position to the (N) position, it is easily understood that each part moves opposite to the above description.

Further, in order to return from the (H) position to the (L) position or to return from the (L) position to the (N) position, the foot petal 57 is pushed in instead of rotating the operation lever 26 by hand. Thus, the engagement between the detent fitting 52 and the cam plate 39 may be released.

As described above, according to the present invention, at least three operation levers are moved from one direction to the other direction through the locking rotator that rotates integrally with the operation lever and the detent fitting that engages with and disengages from the operation lever. It is configured to be rotatable so that it can be held in one position,
A swinging arm that is rotatable coaxially with the rotation fulcrum of the detent fitting and a swinging arm of a tension roller that tensions the endless belt are interlockingly coupled via a first coupling body and a biasing spring. , The power transmission is turned off by rotating the operation lever in one direction by engaging and disengaging the trochanter in the swing arm and the cam portion of the cam plate that rotates integrally with the operation lever.
While the power transmission is turned on by turning in the other direction, the cam plate of the operation lever and the operation shaft for switching the transmission mechanism between high and low are interlocked via the second connecting body. When the operation shaft is connected, the operation shaft is positioned on the low speed side with the power transmission turned on, and when the operation lever is further rotated in the other direction, the operation shaft is rotated to the high speed side, Since the engagement / disengagement phase between the trochanter of the swing arm and the cam portion of the cam plate is set, in order to start driving the farm work machine from the stopped state, be sure to pass the low speed stage from the neutral position where power transmission is OFF. Since the vehicle shifts to the high speed, the shifting work can be smoothly and naturally executed without suddenly shifting from the stopped state to the high speed.

In addition, during a gear shift operation between a low-speed gear and a high-speed gear, it is possible to shift to either a high-low gear or a low-speed gear without passing through the neutral position (position where the clutch is OFF). Less shock when changing.

Further, since the clutch petal and the detent metal fitting are wire-connected and configured to release the engagement with the locking trochanter by pressing the clutch petal, the power transmission is once performed by pressing the clutch petal. If the foot is released from the clutch petal to transmit power again after the cutoff, the rotating posture of the operating lever returns to at least the low speed side, so there is no danger of suddenly running at high speed, and the engine is not overloaded. It is possible to perform the intermittent operation of the power and the shift operation at the same time with a single operating lever without giving them, and the operation work is extremely simple and convenient.

If the first connecting body and the second connecting body are composed of the outer sleeve and the inner wire, the installation positions of the operation lever, the rotating arm, and the operation shaft are restricted as in the case of the link mechanism. And the degree of freedom in design is increased.

[Brief description of drawings]

The drawings show an embodiment of the present invention. Fig. 1 is a plan view of a riding-type rice transplanter, Fig. 2 is a side view, Fig. 3 is a side view of main parts, and Fig. 4 is a view taken along line IV-IV of Fig. 3. FIG. 1 ... Traveling vehicle, 2 ... Engine, 5 ... Gate frame, 4 ... Mission case, 8,9 ... Wheels, 12 ... Seedling planting device, 20 ... Endless belt, 22 ... Steering column, twenty four
…… Seat, 26 …… Operating lever, 27 …… Interlocking mechanism, 28 ……
Output shaft, 30 …… input shaft, 29,31 …… pulley, 32 …… rotating arm, 33 …… tension roller, 34 …… first connected body,
46 …… Second connecting body, 35 …… Spring part, 37 …… Spindle, 38 ……
Swing arm, 39 ... Cam plate, 40 ... Rotor, 41 ... Rotating support shaft, 42 ... Recess, 48 ... Link, 45 ... Engaging pin, 49 ...
… Operation shaft, 51 …… Biasing spring, 55,59 …… Spring, 56 …… Wire, 57 …… Foot petal, 52 …… Detent metal fitting.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroshi Kitagawa, Hiroshi Kitagawa 1-32, Chaya-cho, Kita-ku, Osaka City, Osaka Takayuki Chima (56) Bibliography Sho 61-138726 ( JP, U)

Claims (1)

[Scope of utility model registration request] 1. A transmission comprising a transmission case mounted on an agricultural work machine, wherein a transmission mechanism for switching between high speed and low speed is provided, and power is transmitted to an input shaft to the transmission case via an endless belt. A locking lever that rotates the one operating lever integrally with the operating lever,
It is configured to be rotatable so that it can be held in at least three positions from one direction to the other direction through a detent metal fitting that is engaged with and disengaged from this, and is rotatable coaxially with the rotation fulcrum of the dedent metal fitting. A swing arm and a swing arm of a tension roller that tensions the endless belt are interlocked via a first connecting body and an urging spring, and a trochanter in the swing arm,
By engaging and disengaging the cam part of the cam plate that rotates integrally with the operation lever, power is transmitted by rotating the operation lever in one direction.
It is configured to switch to OFF and to turn on power transmission by turning in the other direction, while the cam plate in the operation lever and the operation shaft for switching the transmission mechanism to high or low,
When the operation shaft is positioned on the low speed side while the power transmission is turned on and the operation lever is further rotated in the other direction, the operation shaft is operated at a high speed by interlocking connection through the second connecting body. The engagement / disengagement phase between the trochanter of the swing arm and the cam portion of the cam plate is set so as to rotate to the
Wire connection between the clutch petal and the detent metal fitting,
A gear shift operating device for an agricultural working machine, characterized in that the engagement with the locking trochanter is released by pressing the clutch petal, and the rotational posture of the operating lever is returned to at least the low speed side.