JPH08252002A - Operation part structure of hydraulic mobile farm working machine - Google Patents

Abstract

PURPOSE: To provide a structure capable of smoothly performing the steering and speed-changing operations of a machine body. CONSTITUTION: A pair of variable flow control pumps are provided with a swash plate angle controlling means 136 for controlling the swash plate of each variable flow control pump. The, base end part of a spool control lever 100 is connected to a servo-spool 141 attached to the swash plate angle controlling means 136. An end of a connection rod of a pump acceleration and deceleration mechanism is connected to the tip end of the spool control lever 100. The middle part of the spool control lever 100 is pivoted with a pivoting shaft 144 directing its axis in a direction perpendicular to the axial line of the serve-spool. The axial line of the serve-spool 141 connected with the base end part of the spool control lever 100 and the axial line of the connection rod connected to the tip end part are positioned on the same imaginary straight line nearly perpendicular to the pivot of the spool control lever 100.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operating section structure of a hydraulic traveling agricultural working machine provided with a crawler type traveling section.

[0002]

2. Description of the Related Art Conventionally, as a hydraulic traveling agricultural working machine provided with left and right independent crawler type traveling parts, there is a combine, for example, in which a left and right traveling hydraulic motor is provided to each of a pair of left and right crawler type traveling parts. A variable flow control pump is connected to each traveling hydraulic motor via a closed circuit oil passage, and each traveling hydraulic motor can be driven by each variable flow control pump. The trunnion lever of each variable flow control pump is provided. In addition, two rod-shaped operation levers provided independently on the left and right are interlocked and linked, and the steering operation can be performed by rotating each operation lever in the front-rear direction.

[0003]

However, in the case where the pair of variable flow rate control pumps are pivotally operated by the independent left and right operation levers like the above-mentioned combine, when the operation lever is short, the operation load is large. On the other hand, when the operation levers are long, there is a problem that the range of rotation operation of each operation lever becomes large, and a smooth turning operation cannot be performed in any case.

[0004]

Therefore, in the present invention, the left and right traveling hydraulic motors are respectively provided in the pair of left and right crawler type traveling portions, and a pair of variable flow rate control pumps are provided in each of the traveling hydraulic motors. In the hydraulic traveling agricultural work machine, which is connected via a road, and the operating parts are interlockingly connected to both variable flow rate control pumps, and the operating parts can be operated to steer and shift the steering operation. A steering box for accelerating and decelerating a pair of pump accelerating / decelerating mechanisms provided between the pair of variable flow rate control pumps in association with the mechanism and the speed change operation mechanism is provided. The swash plate angle control means for controlling the swash plate of the flow rate control pump is provided, and the base end side of the spool control lever is connected to the servo spool provided in the swash plate angle control means. One end of the connecting rod of the pump acceleration / deceleration mechanism is connected to the tip end side of the lever lever, and the middle portion of the spool control lever is pivotally supported by a pivot shaft whose axis is orthogonal to the axial direction of the servo spool. The axis line of the servo spool connecting the base end side of the spool control lever and the axis line of the connecting rod connected to the tip end side are positioned on a virtual collinear line substantially orthogonal to the pivot axis of the spool control lever. The operating structure of the hydraulic traveling agricultural working machine is provided.

[0005]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 is an agricultural tractor as a hydraulic traveling agricultural working machine equipped with an operating portion M according to the present invention. The agricultural tractor A has a rotary tiller working machine B at the rear. Lifting mechanism C of three-point link type
It is connected so that it can be moved up and down so that various work machines can be used.

As shown in FIG. 1 and FIG. 2, the agricultural tractor A has a body frame 3 which is horizontally mounted between the traveling frames 2 and 2 of a pair of left and right crawler type traveling portions 1 and 1 to form the same body frame. 3 is provided with a prime mover portion 4 on the front portion thereof, while an integral support machine frame 5 is mounted on the rear portion thereof via front and rear vibration isolator (not shown), and the cabin 8 and the fuel are mounted on the same body support machine frame 5. A tank 9 and a hydraulic oil tank 10 are provided.

As shown in FIGS. 1 and 2, the prime mover section 4 is arranged in this order from the front end of the machine body frame 3 toward the rear, and includes a condenser 13, an oil cooler 14, a radiator 15, an engine 16, a muffler 17, and a main cleaner 18. , And a pre-cleaner 19 are arranged, and an air cut plate 20 is erected from the machine body frame 3 between the engine 16 and the main cleaner 18, and the prime mover part 4 and the bonnet 21 are the same. The front end edge of the bonnet (21) is covered with a front grille (22) that is openably and closably attached to the front through a pivot bracket (23).

As shown in FIGS. 1 and 2, a cabin 8 is mounted on the integrated support frame 5, and an operating section M is provided on a floor F in the cabin 8 and the operating section is provided. By using M, the rotation ratio of the left and right traveling hydraulic motors ML and MR, which will be described later, is changed, and the left and right traveling variable flow control pumps PL and PR are controlled to synchronize and accelerate the left and right traveling hydraulic motors ML and MR. In addition, the operating unit Q is configured by enabling the steering and gear shifting operation of the machine body and disposing the seat 26 at a position immediately behind the operation unit M via the seat support 27.

Next, the operating portion M, which is the subject matter of the present invention, will be described with reference to FIGS.

That is, as shown in FIGS. 3 to 6, the operating section M includes a stay box 40 that extends between the pair of left and right machine body frame forming bodies 3a, 3a and extends in the left-right width direction.
The steering box 40 allows the pair of pump accelerating and decelerating mechanisms N, N to be accelerated and decelerated by interlocking with a steering operating mechanism 33 and a gear shift operating mechanism 37 which will be described later.

On the steering box 40,
As shown in FIGS. 3 to 5, the handle column 28 is erected,
A circular handle 29 that forms a part of the steering operation mechanism 33 is attached to the upper end of the handle column 28, and a forward / backward speed adjustment lever that forms a part of the speed change operation mechanism 37 near the left side of the handle 29. While the 30 is mounted, an accelerator lever 81 is attached at a position near the right side, a PTO on / off lever 82 is attached at a position directly below the accelerator lever 81, and a brake pedal 31 is provided at an upper left position of the steering box 40. Reference numeral 85 is a brake pedal lock mechanism, 85a is a lock hook, and 85b is a lock hook rotation operation lever.

The steering operation mechanism 33 described above is shown in FIGS.
As shown in Fig. 5, the lower end of the lower half transmission shaft 33a extending in the vertical direction is connected to the pinion shaft 46a protruding upward from the front center of the ceiling wall of the steering box 40 by the interlocking coupling body 33.
An upper half transmission shaft that extends upward and rearward at the upper end of the lower half transmission shaft 33a that is interlockingly connected vertically via b
The lower end of 33c is interlockingly connected via a universal joint 33d, and the center part of the circular handle 29 is attached to the upper end of the upper half transmission shaft 33c, and the upper half transmission shaft 33c is the transmission shaft. Insert into the insertion tube 33e to insert the same transmission shaft.
33e is supported by a support frame 32 mounted in the handle column 28.

In this way, by rotating the handle 29, the upper half transmission shaft 33c → the universal joint 33d → the lower half transmission shaft 33a → the interlocking coupling body 33b → the pinion shaft 46a of the steering box 40 is rotated. The dynamic operating force is transmitted, and the steering box 40 → a pair of pump acceleration / deceleration mechanisms N, N → a pair of variable flow rate control pumps PL, PR → a left / right traveling hydraulic motor ML, MR → a crawler type left / right traveling section 1, 1 The steering operation of is made possible.

At this time, the pinion shaft 46a of the steering box 40 attached to the machine body frame 3 and the steering operation mechanism 33.
The lower half of the lower half of the transmission shaft 33a is interlocked with the interlocking link 33b to absorb the vibration of the machine frame 3 generated during traveling by the interlocking link 33b, and the vibration to the steering wheel 29. To prevent the spread of.

Therefore, it is possible to prevent an erroneous operation of the operator who carries out the steering operation by gripping the handle 29 and to improve the operability of the machine body.

Moreover, by operating the circular handle 29, a pair of variable flow rate control pumps PL, PR are provided via the steering box 40 and the pair of pump acceleration / deceleration mechanisms N, N.
Since it is possible to accelerate and decelerate, the operating load can be reduced, and smooth and reliable steering operation can be performed even in muddy wetlands, which also improves the operability of the aircraft. Can be made.

As shown in FIGS. 3 and 5, the speed change operation mechanism 37 includes a shaft support pipe extending in the lateral width direction of the support frame 32.
The lower end of the forward / backward speed adjusting lever 30 that extends 65 horizontally and inserts a lever support shaft 66 that extends in the left-right width direction into the coaxial support pipe 65 and extends upward to the left end of the lever support shaft 66. Is connected via a connecting body 34, an operating arm 67 is projected forward in the middle of the lever support shaft 66, and the upper end of the connecting rod 68 is connected to the front end of the operating arm 67. A boss portion 69 having an axis lined in the left-right width direction is attached to the left side portion of the front wall of the steering box 40 via a mounting bracket 70, and a support shaft 71 extending in the left-right width direction is inserted into the boss portion 69, and the support shaft is attached. 71
The base end of the arc-shaped arm 72 is attached to the right end of the arm 72, the lower end of the connecting rod 68 is connected to the tip of the arc-shaped arm 72, and the base end of the arm 73 is bossed to the left end of the support shaft 71. A connecting portion 75, one end of a connecting rod 75 is connected to the tip of the arm 73, and the other end of the connecting rod 75 is a boss portion provided on the left end portion of the speed change shaft 41 of the steering box 40 described later. It is connected to an arm 77 protruding from 76.

In this way, the forward / backward speed adjusting lever 30
When the lever is rotated forward on the forward operation side or backward on the reverse operation side, the turning force of the lever 30 causes the lever support shaft to rotate.
66-> operating arm 67-> connecting rod 68-> arcuate arm 72-> spindle 71-> boss 74-> arm 73-> connecting rod 75-> arm 77->
The transmission shaft 41 is transmitted to the transmission shaft 41 to rotate the transmission shaft 41.

Moreover, the gear shift operating mechanism 37 is provided with lever operating position holding means 78 as shown in FIGS. 3 and 5, and the lever operating position holding means 78 is provided on the left end surface of the shaft support pipe 65. A ring-shaped friction plate receiver 79 is attached, and a ring-shaped friction plate 80 is interposed between the friction plate receiver 79 and the operating arm 67, while the lever support shaft is inserted into the shaft support pipe 65.
A spring support protrusion 66a is provided at the right end of the shaft 66 so as to protrude outward from the right end of the shaft support pipe 65, and a spring receiver 66 is attached to the outer end of the spring support protrusion 66a.
The spring 84 is provided between the shaft support pipe 65 and the spring support 66c provided on the right end surface of the shaft support pipe 65.
It is wound around and intervened.

In this way, the lever operation position holding means
In 78, the friction plate 80 is clamped by the friction plate receiver 79 and the operating arm 67 by the pressing force of the spring 84, and the forward / backward speed adjusting lever 30 is rotated in the forward / backward direction by the friction plate 80. When you release your hand, the friction plate 80
It allows the 30 to be held in its operating position.

Further, as shown in FIGS. 3 and 5, the forward / reverse speed adjusting lever 30 is provided with a lever restricting body 110 capable of adjusting the range between the lever neutral restriction and the lever speed changing operation restriction and the speed changing operation mechanism 37. Are connected by another route.

That is, as shown in FIGS. 3 and 5, the lever restricting body 110 has a boss portion 111 having an axis lined in the left-right width direction attached to the supporting machine frame 32, and a swinging support shaft in the boss portion 111. 11
2 is swingably supported, and the middle part of the slide guide cylinder 113 extending vertically is integrally attached to the left end of the rocking support shaft 112 so that the middle part of the slide guide cylinder 113 swings together with the middle part. Neutral regulation ball accommodating portions 114 and 115 are formed in the support shaft 112, respectively, and the neutral regulation balls are biased in the accommodating portions 114 and 115 by springs 116 and 116 in opposite directions.
While housing 117, 117, a slide rod 118 having an upper end connected to the operating arm 67 is vertically slidably inserted into the slide guide cylinder 113, and a neutral regulation ball engaging groove 118a is formed on the peripheral surface of the slide rod 118 in the middle thereof. The forward speed limiter 119 and the reverse speed limiter at the upper and lower ends, respectively.
120 and 120 are screwed in the axial direction of the slide rod 118 so that the forward and backward positions can be adjusted.

In this way, the forward / backward speed adjusting lever 30
Is in the neutral position, the neutral restriction balls 117, 117 are engaged in the neutral restriction ball engaging groove 118a, and when the lever 30 is operated to switch to the forward side or the reverse side, the spring 11
Since it is necessary to disengage the neutral restriction balls 117, 117 from the neutral restriction ball engaging groove 118a by sliding the slide rod 118 against the pressing biasing force of the 6,116, the operator moves the lever 30 to the neutral position. By doing so, it is possible to easily experience the fact that the neutral position is switched to either of the forward and backward movements to prevent erroneous operation.

Then, when the forward / backward speed adjusting lever 30 is rotated forward to the forward operation side, the slide guide cylinder 11
The forward speed regulator 119 comes into contact with the upper end surface of 3 and
When the lever 30 is rotated rearward, which is the backward operation side, while the forward operation of the lever 30 is restricted, the reverse speed regulator 120 comes into contact with the lower end surface of the slide guide cylinder 113, and the backward operation of the lever 30 is prevented. I am trying to regulate it.

At this time, the forward / rearward travel speed regulating members 119, 120 are adjusted in advance / retreat positions in the axial direction of the slide rod 118 so that the forward / backward travel restriction range can be appropriately adjusted according to the operator's preference. There is.

Moreover, the lever restricting body 110 is provided on a different path from that of the speed change operation mechanism 37 in which the connecting rod interposed between the tip end of the actuating arm 67 swinging in the vertical direction and the arcuate arm 72 makes an elliptic motion, that is, Since the slide guide cylinder 113 swings in the front-rear direction about the swing support shaft 112, it is interposed between the actuating arm 67 that swings in the vertical direction and the fixed swing support shaft 112. Nevertheless, the slide rod 118 slides smoothly in the slide guide cylinder 113, so that the neutral regulation and the forward / reverse regulation of the forward / backward speed adjusting lever 30 can be surely performed.

Further, the forward / backward speed adjusting lever 30 for adjusting the forward / backward speed of the left and right traveling parts 1, 1 is provided with a handle.
By arranging it near the left side of 29, and by arranging the tip gripping part 30a of the forward / backward speed adjusting lever 30 close to the gripping part of the handle 29, the operator can handle with the right hand.
The operator can easily operate the forward / backward speed adjusting lever 30 with his / her left hand while gripping 29 and performing a steering operation. Therefore, a safe and reliable steering operation can be performed even in a work that requires frequent forward / reverse switching operations, and the operability of the machine body can be improved.

The brake pedal 31 is shown in FIGS. 4 and 5.
As shown in, the pedal arm 31c is attached to the pedal support shaft 31a protruding from the support frame 32 in the left-right width direction via the boss portion 31b, and the operating arm 31d is attached to the front lower portion of the boss portion 31b. Projecting toward, and connecting rod to the actuating arm 31d.
While connecting the upper end of 31e, a pilot oil passage switching valve 94 is attached to the front wall of the steering box 40 via a stay 40b, and the connecting rod is connected to the spool 94a of the valve 94.
The lower end of 31e is connected. 31f is a pedal restoring spring In this way, by depressing the brake pedal 31, the boss portion 31b → the operating arm 31d → the connecting rod 31e → the spool 94a can be operated to switch the pilot oil passage. I am trying.

Here, in the embodiment of the present invention, as shown in FIGS. 3 and 7, a two-pump / two-motor type HST is used as a continuously variable transmission, and the left and right traveling sections 1 and 1 travel separately. It is drivable, and the handle 29 is of a rotary type, and by changing the number of rotations and the direction of rotation of each crawler of the left and right traveling units 1 and 1 in accordance with the amount of rotation, the aircraft can be turned, and at the same time. By rotating the forward / backward speed adjustment lever 30, the left and right hydraulic motors ML, MR
The number of rotations and the direction of rotation can be changed.

The forward / backward speed adjusting lever 30 and the handle 29 are constructed so that they can be operated separately, and are linked to a pair of left and right pump accelerating / decelerating mechanisms N, N in the steering box 40 to accelerate and decelerate both pumps. As shown in FIG. 7, the mechanisms N and N are linked to the left and right swash plates 98 and 99 of the variable flow control pumps PL and PR of the HST, and the left and right traveling hydraulic motors ML and MR are respectively connected to the pumps PL and PR. By connecting them, the left and right swash plates 101 and 102 of the hydraulic motors ML and MR are controlled, respectively, so that the left and right traveling parts 1 and 1 can be moved forward, backward and stopped, respectively.

Next, the hydraulic circuit K will be described with reference to FIG. That is, the hydraulic circuit K connects the HST hydraulic circuit 90 to the hydraulic tank T, connects the left side traveling unit driving hydraulic circuit 91 and the right side traveling unit driving hydraulic circuit 92 to the HST hydraulic circuit 90, respectively. The working machine lifting hydraulic pump P1 linked to the pair of variable flow control pumps PL and PR of the circuit 90 is connected to the working machine lifting hydraulic circuit 93, while the charge pump linked to the variable flow control pumps PL and PR is linked. Connect the brake devices 95 and 96 provided in the left and right side drive hydraulic circuits 91 and 92 to P2 via the pilot oil passage 135,
A pilot oil passage switching valve 94 is attached in the middle of the pilot oil passage 135. 97 is a bypass operation switching valve.

The brake pedal 31 is interlocked with the pilot oil passage switching valve 94, and the pilot oil passage switching valve 94 is switched in association with the depression operation of the brake pedal 31, and the brake device 95, The 96 is configured to brake.

That is, the brake devices 95, 96 are provided with piston rods 95c, 96c urged in the extension direction by springs 95b, 96b in cylinders 95a, 96a, respectively, and a pressure contact member is provided at the tip of each piston rod 95c, 96c. 95d, 96d are attached, and each pressure contact body 95d, 96d is connected to the drive wheel 1a, 1a of each traveling section 1, 1.
By supplying pilot oil into each cylinder 95a, 96a, the piston rods 95c, 96c are shortened against the bias of the springs 95b, 96b, and the pressure contact body is pressed.
By separating 95d and 96d from the drive wheels 1a and 1a so that they can be brought into a non-brake operating state, by discharging pilot oil from each cylinder 95a and 96a,
The urging force of the springs 95b, 96b causes the piston rod 95c,
96c is extended to drive the pressure contact bodies 95d and 96d to drive wheels 1a and 1a.
It is possible to bring the brakes into operation by putting them in pressure contact with each other.

In this way, by depressing the brake pedal 31, the driving of the left and right running parts 1, 1 can be stopped at the same time by the left and right brake devices 95, 96. Brake depressing operation can be performed with the same feeling as depressing operation, and good safety can be ensured.

In the middle of the pilot oil passage 135,
As shown in FIG. 7, a branch pilot oil passage 137 is connected via a pilot oil passage switching valve 94. The branch pilot oil passage 137 has its tip bifurcated and the tip branch oil passages 137a, 137a. On the other hand, the pair of variable flow rate control pumps PL and PR are provided with swash plate angle control means 136 and 136, respectively, and the swash plate angle control means 136 and 136 are provided with the tip branch oil passages 137a and 137a.
Are connected.

The swash plate angle control means 136, as shown in FIG.
The middle part of the servo cylinder 140 extending in a direction substantially orthogonal to the extending direction of the trunnion arm 139 is pivotally connected to the tip of the 139, and is inserted into the servo cylinder 140 so as to penetrate the servo spool 141. And servo spool
The base end of the spool control lever 100 is pivotally connected to one end of the 141, and the middle part of the spool control lever 100 is connected to the lever support part 143 formed on the machine frame of the variable flow control pump PL. It is pivotally supported by a pivot 144 whose axis is oriented in a direction orthogonal to the axial direction.
145 are neutral biasing springs for restoring the servo cylinder 140 to the neutral position, which are arranged on both sides of the servo cylinder 140 in the sliding direction. Reference numerals 146 and 147 are connecting pins.

Then, the oil passage 141a formed on the peripheral surface of the servo spool 141 and the tip branch oil passage 137a of the branch pilot oil passage 137 are communicatively connected, and the oil passage of the servo spool 141 is connected from the tip branch oil passage 137a. Servo cylinder 14 through 141a
A fixed amount of pilot oil is supplied to the inside of 0, and the servo cylinder 140 can be slid by a fixed amount along the servo spool 141 according to the supply amount of the pilot oil.

In this way, when the steering wheel 29 and the forward / backward speed adjusting lever 30 are operated to perform the steering / shift operation, the steering operation mechanism 33, the shift operation mechanism 37, the steering box 40, the pump The spool control lever 100 is oscillated through the speed increasing / decreasing mechanism N, and the servo spool 141 is pushed and pulled in one of the directions by interlocking with the spool control lever 100.
A certain amount of pilot oil is supplied from the end branch oil passage 137a into the servo cylinder 140 according to the sliding amount of 1, and the servo cylinder 140 slides in either direction according to the supplied pilot oil amount. Linked trunnion arm
139 is rotated by a certain angle, and the trunnion arm 139
The swash plate operating shaft 138 is rotated by a fixed angle in accordance with the rotation angle of the swash plate 138, the angle of the swash plate 98 linked to the swash plate operating shaft 138 is changed, and the flow rate of the variable flow rate control pump PL is controlled. I am trying to do it.

At this time, when the brake pedal 31 is stepped on, the pilot oil passage switching valve 94 is switched in conjunction with the stepping operation, and as described above, the brake device 95 of the left and right traveling parts 1, 1 is operated. , 96 brakes, the pilot oil in the branch pilot oil passage 137 is drained, the pilot oil supplied in the servo cylinder 140 is also drained, and the servo cylinder 140 is neutrally returned by the neutral return springs 145,145. In conjunction with the servo cylinder 140, the trunnion arm 139 → swash plate angle operating shaft 138 → swash plate 98 is returned to the neutral position, and the variable flow control pump
Closed circuit oil passage between PL and hydraulic motor ML for left driving
The hydraulic fluid in 148 is stopped flowing.

Here, the other variable flow rate control pump PR
Also has swash plate angle control means 136 so that the same swash plate angle control as described above can be performed, and a closed circuit oil is provided between the variable flow rate control pump PR and the right traveling positive hydraulic motor MR. The passage 149 is provided so that the hydraulic oil in the closed circuit oil passage 149 also stops flowing when the brake pedal 31 is depressed.

Therefore, the braking by the brake devices 95, 96 and the stoppage of the flow of the hydraulic oil by the pair of variable flow rate control pumps PL, PR in which the swash plate angles 98, 99 are in a neutral posture cooperate with each other, It is possible to smoothly and reliably stop the driving of the left and right traveling parts 1 and 1, and it is possible to prevent the generation of vibration and noise by stopping the flow of hydraulic oil.

Further, the handle 29 and the forward / backward speed adjusting lever
By operating 30, the servo cylinders 140,140 are slid by the pilot pressure by the servo spools 141,141, and the trunnion arms 139,139 are operated in synchronism with the servo cylinders 140,140. Flow control pump
Since the PL and PR swash plates 98 and 99 can be controlled, it is possible to reduce the operational load of the forward / backward speed adjusting lever 30 using pilot pressure. It can be shortened to be compactly arranged in the vicinity of the handle 29, and the lever operation can be performed smoothly and reliably.

Moreover, since the operating position of the forward / backward speed adjusting lever 30 is held by the lever operating position holding means 78, the brake pedal 31 is depressed to stop the driving of the left and right traveling parts 1, 1. In this case, the pilot oil passage switching valve 94 shuts off the pilot oil passage, that is, the pilot oil is drained, and the servo cylinder 140,
140 is returned to the neutral position by the neutral biasing springs 145 and 145, and the swash plates 98 and 99 are set to the neutral position via the trunnion arms 139 and 139.However, when the depression operation of the brake pedal 31 is released, the forward / backward speed adjustment lever 30 Since the servo spools 141, 141 that are linked and linked to each other are held in their original lever operating positions, pilot oil flows into the servo cylinders 140, 140 through the pilot oil passages, and the swash plates 98, 99 return to their original swash plate angles. Thus, the aircraft can be run at the original set speed, and the steering operation can be efficiently performed.

Here, the spool control lever 100
As shown in FIG. 9, the stepped portion 100a is formed by bending it upward or downward from the middle portion, and one end of a second connecting rod 89 of a pump acceleration / deceleration mechanism N, which will be described later, is attached to the tip end side of the rod connecting shaft. 89a, and the axis of servo spool 141 that connects the base end side of spool control lever 100 with the second connecting rod 89 that connects to the tip end side.
Axis of the spool control lever 100
It is located on a virtual collinear line L substantially orthogonal to 4. 89
b is a rod connecting nut.

In this way, when the steering section and the speed change operation are performed by the operation section M, the flow rate control of the variable flow rate control pumps PL, PR can be smoothly performed through the swash plate angle control means 136, 136. The left and right traveling hydraulic motors ML and MR can surely accelerate and decelerate the left and right traveling parts 1 and 1, so that the steering and gear shifting operations can be smoothly performed, and the operability of the aircraft can be improved. I am able to do it.

Moreover, the spool control lever 100
Is formed with a stepped portion 100a between the base end side and the tip end side, and the axis of the servo spool 141 connecting the base end side and the second connecting rod 89 connected to the tip end side. Axis and
Since the spool control lever 100 is positioned on a virtual straight line L that is substantially orthogonal to the pivot 144, the spool control lever 100 that operates the servo spool 141 when the second connecting rod 89 slides has a moment in the twisting direction. The servo spool 141 can be smoothly and reliably slid without any action, and the swash plate angle control can be smoothly and surely performed, which also improves the operability of the machine body. I'm trying to come.

Next, the internal structure of the steering box 40 will be described. Since the steering box 40 is structured substantially symmetrically, one side will be described.

That is, in the internal structure of the steering box 40, as shown in FIGS. 10 to 12, a slide shaft 44 is horizontally installed in parallel with the transmission shaft 41 in front of the transmission shaft 41 having a triangular sectional shape. ing. A pair of left and right slide bodies 43, 43 are fitted onto the transmission shaft 41 so as to be slidable in the axial direction, and a slide acting body 45 interlockingly connected to the handle 29 is arranged between the slide bodies 43, 43. , Each slide body 43, 43 and a pair of variable flow rate control pumps PL, PR spool control lever 10
A pair of pump acceleration / deceleration mechanisms N, N are provided between 0 and 100, and each pump acceleration / deceleration mechanism N includes a guide body 50, a rotor 51, a rotor support arm 52, and a swash plate operating arm 55. And the first connecting rod 56, the first arm 86, the intermediate shaft 87, and the second arm 88.
And a second connecting rod 89.

The slide acting body 45 includes a base portion 45a attached to the slide shaft 44 so as to be slidable in the axial direction, and a main body 45b integrally attached to the base portion 45a and arranged immediately in front of the slide shaft 44. The main body 45b is shaped like a gate in a front view, and a rack 45c formed by extending in the left-right width direction is fixed to the upper surface of the main body 45b.

A pinion gear 46 meshes with the rack 45c. The pinion gear 46 is fixed to the pinion shaft 46a, and the pinion shaft 46a is interlockingly connected to the lower end of the lower half transmission shaft 33a of the handle 29 arranged above through the interlocking coupling body 33b. Therefore, when the handle 29 is rotated, the pinion gear 46 rotates, the rack 45c interlocks and slides in the left-right width direction, and the slide action body 45 slides accordingly, and the left and right sides of the slide action body 45. One of the slide bodies 43, 43 engaged with the ends is pulled.

Here, while the rack 45c is detachably attached to the main body 45b of the sliding action body 45, the pinion gear 46 is detachably attached to the pinion shaft 46a so that the gear ratio of the rack 45c and the pinion gear 46 can be changed. It is also possible to obtain the responsiveness of the turning operation adapted to the operator's preference.

An arm support portion 47a of a guide support arm 47 is loosely fitted to the outside of the outer peripheral surface of the slide body 43, and a detent body 47b is provided from the rear outer peripheral surface portion of the arm support portion 47a toward the transmission shaft 41. The same rotation stop body 47b is loosely fitted to the speed change shaft 41 via the interlocking slide body 48 so as to be slidable in the left and right axial directions. On the other hand, a boss portion 47d is formed on the rear portion of the arm support portion 47a, and a pivot pin whose axis is vertically oriented to the boss portion 47d.
The upper end of 47e is pivotally supported, and the center of the upper wall of the guide body 50 is rotatably attached to the lower end of the pivotally supported pin 47e. The guide body 50 extends in the left-right direction and has a U-shaped cross-section when the lower surface is opened.

Further, a swing arm 48a extends downward from the lower portion of the outer peripheral surface of the interlocking slide body 48, and a rear end of a swing link 48c, which is adjustable in expansion and contraction, is connected to a lower end of the swing arm 48a by a connecting pin 48b. The front end of the swing link 48c is pivotally supported on the one end of the upper wall of the guide body 50 via a connecting pin 48d. 48e is a neutral return spring interposed between the pair of left and right interlocking slide bodies 48, 48.

A rotatable rotor 51 is inserted in the recess of the guide body 50 and is slidably fitted in the left-right direction. The shaft center of the rotor 51 is in the left-right width direction. Is attached to one end of the rotor support arm 52 extending to the other side, and the other end of the rotor support arm 52 is attached to the steering box 40.
A boss portion 53 fixed to the bottom wall of the steering box 40 is pivotally supported by an arm support shaft 54 having an axis oriented in the vertical direction so that the arm support shaft 54 can swing left and right.
The end of the swash plate actuating arm 55 extending in the left-right width direction is fixed to the end of 54 by a fixing bolt 55a, and the other end is connected to one end of a first connecting rod 56 via a connecting pin 56a. The tip end of the first arm 86 is connected to the other end of the one connecting rod 56, and the base end of the first arm 86 is attached to the upper end of the intermediate shaft 87 attached to the HST via the stay 130 with its axis extending vertically. The base end of the second arm 88 is attached to the lower end of the intermediate shaft 87, and the second connecting rod is attached to the tip of the second arm 88.
One end of 89 is connected, and the other end of the second connecting rod 89 is HS.
It is connected to the T spool control lever 100.

Moreover, the pair of left and right first connecting rods 56, 56
Have substantially the same length, and the pair of left and right second connecting rods 89, 89 also have substantially the same length.

In this way, when the steering operation is performed by the handle 29, the operation amounts of the pair of first connecting rods 56, 56 and second connecting rods 89, 89 can be evenly secured, The flow rate of the pair of variable flow rate control pumps PL, PR can be smoothly controlled through both connecting rods 56, 56 and 89, 89, and the left and right traveling parts 1, 1 can be increased or decreased by the left and right traveling hydraulic motors ML, MR. I'm trying to make sure I can do it fast. Therefore, it is possible to smoothly carry out the steering and gear shifting operations of the machine body and improve the operability of the machine body.

In such a structure, the rotation of the handle 29 causes the slide action body 45 to slide, and one of the slide bodies 43, 43 is pulled along the slide shaft 44 and the speed change shaft 41, so that the slide body 43 and The guide body 50 provided integrally is slid.

When the speed change shaft 41 is rotated by the forward / reverse speed adjusting lever 30, the guide body 50 is moved forward and backward around the pivot pin 47e via the swing link 48c connected to the slide body 43. The arm 55 for rocking is swung around the arm support shaft 54.

Next, the state of the guide body 50 when the handle 29 and the forward / backward speed adjusting lever 30 are operated is shown in FIGS.
Will be described with reference to.

That is, when the forward / reverse speed adjusting lever 30 is set to the neutral state and the rotary handle 29 is also set to the neutral state at the same time, the left and right guide bodies 50, 50 and the rotor support arm 5 are
2, 52 and the swash plate actuating arms 55, 55 are shown in FIG.
As shown in, it maintains a horizontal posture.

When the forward / reverse speed adjusting lever 30 is operated to shift to the forward shift position from this state, the shift shaft 41 is rotated, and the left and right slide bodies 43, 43, swing arms 48a, 48a, swing links 48c, 48c is interlocked, and the left and right guide bodies 50, 50 are pivotally supported pins.
Rotate around 47e, 47e, and then rotate the left and right rotors 51, 5
1 through rotor support arm 52,52, arm support shaft 54,54
, The swash plate actuating arms 55, 55 are, as shown in FIG.
Be inclined. In this case, the left and right traveling hydraulic motor M
The left and right swash plates 101 and 102 that control L and MR have the same inclination angle, the left and right traveling units 1 and 1 travel forward at the same speed, and the aircraft travels straight.

Next, when the handle 29 is rotated counterclockwise by turning counterclockwise from the straight-ahead state, the pinion shaft 46a rotates, and the rack 45c meshing with the pinion gear 46 moves to the right to move the rack 45a. At the same time, the slide acting body 45 pulls and slides the left slide body 43 to the right side.

Then, the guide body 50 on the left side is the slide body 43.
Together with this, the guide body 50 slides rightward while the guide body 50 slides to the right while maintaining the tilted posture. Then, as shown in FIG. 15, the rotor 51, which has been fitted to the right guide body 50, is pushed downward to be fitted to the substantially central position of the left guide body 50. The left rotor support arm 52 and the swash plate actuating arm 55 are rotated to approach a horizontal posture, and the left swash plate 98 for controlling the left traveling hydraulic motor ML is brought close to a neutral state. In this case, the left traveling unit 1 decelerates or stops from the straight traveling state, and the right traveling unit 1 continues forward traveling, so that the aircraft slowly turns to the left.

Next, in the left turning state, the handle
When 29 is further rotated leftward, the left guide body 50 slides further to the right with the tilted posture, and the left rotor 51 moves to the left side portion of the guide body 50 as shown in FIG. In the mated state, the rotor support arm 52
The swash plate operating arm 55 has a left high tilted right low tilted posture,
The left swash plate 98 is tilted to the reverse control side. In this case, the traveling unit 1 on the left side travels in the reverse direction, while the traveling unit 1 on the right side moves in the forward direction, so that the body makes a spin turn.

FIG. 17 shows a pump acceleration / deceleration mechanism N as another embodiment, in which flexible feedback wires 140, 140 are respectively provided between the swash plate actuating arms 55, 55 and the spool control levers 100, 100. It is installed.

That is, the feedback wire 140 is
The outer wire stay 141 is provided near the swash plate actuating arm 55 at the bottom of the steering box 40, and the outer wire stay 142 is provided near the spool control lever 100 at the side wall of the HST. An outer wire 143 is provided between 141 and 142, and the inner wire 144 is slidably inserted into the outer wire 143 to connect one end of the inner wire 144 to the tip of the swash plate actuating arm 55. The other end is connected to the tip of the spool control lever 100. 145 and 146 are connecting pins, respectively.

In this way, the swash plate operating arms 55, 55
In addition, since the spool control levers 100, 100 are interlockingly connected by the flexible feedback wires 140, 140, respectively, the space for disposing the feedback wires 140, 140 can be made compact and the swash plate actuating arms 55, 55 can be operated. The amount can be reliably transmitted to the spool control levers 100, 100, and the variable flow rate control pumps PL, PR can be accurately accelerated and decelerated.

[0069]

According to the present invention, the following effects can be obtained.

That is, according to the present invention, while the swash plate angle control means for controlling the swash plates of the pair of variable flow rate control pumps is connected to the servo spool at the base end side of the spool control lever, the spool control lever is connected. Since one end of the connecting rod of the pump acceleration / deceleration mechanism is connected to the tip end side of the, and the middle part of the spool control lever is pivotally supported by a pivot axis oriented in a direction orthogonal to the axial direction of the servo spool, When a steering / shift operation is performed by the operation unit, the flow rate control of each variable flow rate control pump can be smoothly performed through the swash plate angle control means, and the left and right traveling units can be increased or decreased by the left and right traveling hydraulic motors. It is possible to reliably carry out speed and smoothly perform steering and gear shifting operations of the machine body, and improve operability of the machine body.

Moreover, the spool control lever has a stepped portion formed between the base end side and the tip end side, and is connected to the front end side with the axis of the servo spool connecting the base end side. Since the axis of the connecting rod is located on a virtual collinear line that is substantially orthogonal to the pivot axis of the spool control lever, a twisting moment acts on the spool control lever that operates the servo spool when the connecting rod slides. Without doing so, the servo spool can be smoothly and reliably slid, and the swash plate angle control can be smoothly and reliably performed. From this point as well, the operability of the machine body can be improved.

[Brief description of drawings]

FIG. 1 is a side view of an agricultural tractor including an operating portion structure according to the present invention.

FIG. 2 is a plan view of the agricultural tractor.

FIG. 3 is a side view of an operation unit.

FIG. 4 is a side view of the operation unit.

FIG. 5 is a front view of the operation unit.

FIG. 6 is a plan view of the operation unit.

FIG. 7 is a hydraulic circuit diagram.

FIG. 8 is a partially cutaway plan view of swash plate angle control means.

FIG. 9 is a partially cutaway front view of a servo spool control lever.

FIG. 10 is a sectional plan view showing the internal structure of the steering box.

FIG. 11 is a sectional front view showing the internal structure of the steering box.

FIG. 12 is a sectional side view showing the internal structure of the steering box.

FIG. 13 is a partial front view of the steering box in a neutral state.

FIG. 14 is a partial front view of the steering box in a straight traveling state.

FIG. 15 is a partial front view of the steering box in a right turning state.

FIG. 16 is a partial front view of the steering box at the time of pivot turn.

FIG. 17 is a plan view of a pump speed increasing / decreasing mechanism as another embodiment.

[Explanation of symbols]

 A Agricultural tractor 1 Travel part 2 Travel frame 3 Airframe frame 4 Motor part

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Takanobu Shimada 428 Enami, Okayama City, Okayama Prefecture Seirei Industry Co., Ltd.

Claims (1)

[Claims] 1. A pair of left and right crawler-type traveling units are provided with left and right traveling hydraulic motors, respectively, and a pair of variable flow rate control pumps are connected to each traveling hydraulic motor via a closed circuit oil passage. In a hydraulic traveling agricultural work machine in which an operating section is linked to a control pump and the operating section can be operated to steer and shift, the operating section is linked to the steering operation mechanism and the shift operation mechanism. A steering box for accelerating and decelerating a pair of pump accelerating / decelerating mechanisms provided between the pair of variable flow rate control pumps is provided, and the pair of variable flow rate control pumps are provided with a swash plate for controlling the swash plate of each variable flow rate control pump. A plate angle control means is provided, and the base end side of the spool control lever is connected to the servo spool provided in the swash plate angle control means, while the pump increase is provided at the tip end side of the spool control lever. By connecting one end of the connecting rod of the speed mechanism, the midway part of the spool control lever is pivotally supported by a pivot axis oriented in a direction orthogonal to the axial direction of the servo spool, and the base end side of the spool control lever is The operating portion of the hydraulic traveling agricultural working machine characterized in that the axis line of the connected servo spool and the axis line of the connecting rod connected to the tip end side are positioned on a virtual collinear line substantially orthogonal to the pivot axis of the spool control lever. Construction.