JPH0662095B2 - Steering device for mobile agricultural machinery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, a hydraulic cylinder is operated via a solenoid valve by a lever operation or a pedal operation, and a clutch and a brake connected to a piston rod of the hydraulic cylinder are connected and disconnected to operate a traveling direction of a machine base. The present invention relates to a steering device for an agricultural machine.

Mobile agricultural machines such as combine harvesters and binders have left and right traveling devices that travel by connecting traveling clutches.
These left and right traveling devices are respectively driven to travel from the respective left and right traveling drive shaft sides that are separately drive-coupled to the driving side. That is, on each of the left and right traveling drive shafts, a clutch and a brake connected to the piston rod of the hydraulic cylinder that moves forward and backward by opening and closing the solenoid valve are provided adjacent to each other, and while the machine base is moving straight, The left and right piston rods are retracted, the left and right clutches are connected, and the left and right brakes are disconnected. When turning the machine base, the solenoid valve on the turning side is opened by operating the lever or the pedal, and the piston rod of the hydraulic cylinder is advanced so that the clutch on the turning side is disconnected and the brake is connected continuously. As a result, the traveling device on the turning side is decelerated or stopped, and the machine base is rotated around the stopping traveling device.

Therefore, conventionally, a device shown in Japanese Patent Laid-Open No. 53-138829 has been proposed as a steering device having a braking force adjusting mechanism. This is because a relief valve with a pressure regulator is provided in the pressure oil supply passage to the hydraulic cylinder, and an operation tool such as a pedal is connected to the pressure control tool, and the brake pressure is adjusted by adjusting the relief valve by operating this operation tool. It is possible to adjust and obtain turning characteristics from a slow turn to a sharp turn.

However, such a conventional steering device is provided with a relief valve and a pressure adjusting tool for the relief valve in the pressure oil supply path between the solenoid valve and the hydraulic cylinder, so that the hydraulic pressure of the hydraulic cylinder and the spring pressure of the spring are increased. Since the clutch is cut and the brake is pressed continuously while adjusting the pressure in a balanced state, not only is it difficult to set the pressure and brake pressure when operating only the clutch,
When it is desired to make the connecting / disconnecting pressure of the clutch larger than the pressing force of the brake, there is a drawback in that the spring force of the spring must be increased more than necessary.

The present invention has been made in view of the above points, and the pressure oil discharge passage is opened after the piston stroke from the clutch entering to the cutting of the hydraulic cylinder for continuously cutting the clutch and pressing the brake. By installing a pressure adjustment device that adjusts the pressure by operating means in the oil discharge passage, it is possible to set the contact pressure of the clutch and the pressing force of the brake separately, improving operability and slow turning. The steering device for a mobile agricultural machine is proposed, which is designed to improve the turning characteristics from turning to sudden turning. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 to 4 show an example in which the steering apparatus according to the present invention is applied to a combine, and FIG. 1 is a schematic side view thereof, and FIG.
The figure is also a vertical cross-sectional view of the main part in the gear box, FIG. 3 is a cross-sectional view of the hydraulic cylinder block, FIG. 4 is a vertical cross-sectional view of the relief valve, and FIG. 5 is a hydraulic piping diagram. In the drawing, a center gear 3 that meshes with a gear 2 that is rotationally driven from the prime mover is fixed to a clutch shaft 1 that is rotatably supported in a gear box of the combine.
Clutch surfaces 3a and 3b are provided. Similarly, on the clutch shaft 1, a pair of left and right clutch gears 4 and 5 are slidably provided on both sides of the center gear 3 so as to be slidable.
Clutch surfaces 4a and 5a which mesh with a and 3b are formed, respectively. In the gear box, each clutch gear 4,
One end of a pair of left and right traveling drive shafts 8 and 9 to which gears 6 and 7 that mesh with 5 are fixed, respectively, and the other end of each traveling drive shaft 8 and 9 is attached to the machine frame traveling frame side. It is supported. The drive wheels of the left and right traveling crawlers are attached to the traveling drive shafts 8 and 9, respectively, and the clutch surfaces 4a and 5a of both clutch gears 4 and 5 mesh with the clutch surfaces 3a and 3b of the center gear 3. Thus, the left and right traveling crawlers are both driven via the gears 6 and 7 and the traveling drive shafts 8 and 9 so that the machine base moves straight. Also,
Outside the left and right clutch gears 4 and 5, the braking surface 4
B and 5b are formed respectively, and further, on the gear box side, brake discs 10 and 11 are provided with brake faces 10a and 11a facing the respective brake faces 4b and 5b.
Is fixed. Then, the respective clutch gears 4, 5 are slid on the clutch shaft 1 to disengage the clutch surfaces 4a, 5a from the clutch surfaces 3a, 3b, whereby the left and right traveling crawlers are decelerated or slowly stopped, and the clutch gears 4, 5 are stopped. 5 is further slid in the same direction, the braking surfaces 4b, 10a and 5b, 11a are engaged with each other to brake the rotation of the clutch gears 4, 5 and the left and right traveling crawlers are further decelerated or steeper than when the clutch is cut. It is configured to stop. By decelerating or stopping one of the left and right traveling crawlers, the machine base is steered so as to turn in the stopping direction. Therefore, a drive device for sliding the clutch gears 4 and 5 of this steering device will be described below. In the following description, the traveling drive shaft 8 side, which is the left side of FIG. 2, is the left side with respect to the machine traveling direction, and the traveling drive shaft 9 side is the right side.

A hydraulic cylinder block generally designated by reference numeral 12 is provided with a left side cylinder 13 and a right side cylinder 14, and on the head end side of each cylinder 13, 14, a port 15,
16 is opened. Reference numeral 17 denotes a three-way switching type solenoid valve, both ports 17a, 17b of which are ports 15, 16
And a hydraulic pump 21 which is driven by a motor 20 to rotate and is connected by a pipe 22. 23 is the tank 2
4 is a relief valve that adjustably regulates the upper limit pressure of the pressure oil sent to the solenoid valve 17 by the hydraulic pump 21 and is provided in the pipe between the pipe 22 and the tank 24. On the other hand, as shown in FIG. 1, a pair of left and right L-shaped levers 25 are pivotally attached to the operating box of the machine base, and a weak spring is attached to the upper free end of each L-shaped lever 25. A pair of left and right operation levers 26, which are urged by a member to rotate in the counterclockwise direction in the drawing, are pivotally mounted with the stoppers 27 having their rotational limits restricted. A switch 28 is supported by the L-shaped lever 25 through a bracket 29, and the contacts are closed by slightly rotating the operating levers 26 in the clockwise direction against the elastic force of the spring members. When the operation lever 26 is further rotated in the same direction after closing the contacts, the L surface lever 25 is rotated to press the push pin 56 described later. Reference numeral 30 and 31 in FIG. 5 denotes a pair of solenoids attached to the solenoid valve 17, which are connected to the respective switches 28 by wiring, and one of the two switches 28 is selected. The solenoid 30 (31) corresponding to this moves the sleep of the solenoid valve 17 to open the port 17a (17b), and the pressure oil is sent to either the cylinder 13 or the cylinder 14. Is configured to.

The cylinders 13 and 14 have a bottomed cylindrical piston 32,
33 is a port 15 due to the compression coil springs 34 and 35.
The piston rods 36, 37 are inserted into the inner holes of the pistons 32, 33 by being urged toward the 16 side so as to move back and forth.
Are each involved. Reference numeral 38 in FIG. 1 denotes a pair of left and right foot pedals located below the machine control box and pivotally supported. The foot pedals 38 act on the piston rods 36 and 37. Each end is pivoted and each foot pedal 38
The rods 39 and 40 pivotally connected to each other extend in the gear box direction. The rods 39 and 40 are pivotally attached to the gear boxes, and one ends thereof are pivotally attached to the other ends of the shifters 41 and 42 engaged with the grooves of the clutch gears 4 and 5, respectively, and together with the pistons 32 and 33, the piston rods 36 and 40. As the 37 moves forward and backward, the foot pedal 38,
The clutch gears 4 and 5 are configured to slide via the rods 39 and 40 and the shifters 41 and 42. Further, when pressure oil is not fed to the cylinders 13 and 14 due to a failure of the hydraulic system or the like, the left and right clutch gears 4 and 5 are individually advanced and retracted by depressing the foot pedals 38.

In each of the cylinders 13 and 14 of the hydraulic cylinder block 12 thus configured, the pressure oil discharge ports 43 and 44 are opened at the stroke intermediate portions of the pistons 32 and 33, and the pressure oil discharge ports 43 and 44 are It is connected to the tanks 47 and 48 by pipelines 45 and 46. Note that FIG. 3 shows a state in which the right piston 32 is also retracted, and half of the left piston 33 starts opening the pressure oil discharge port 44 and half opens the pressure oil discharge port 44. Each of them is shown in a closed state. Reference numerals 49 and 50 are relief valves provided in the respective pipe lines 45 and 46, and are a block 51 and a stepped outer cylinder 52 screwed into the block 51.
An inner cylinder 53 having a stepped inner hole is screwed into the inner hole of the outer cylinder 52 and fixed by a nut 54. A conical valve 55 is seated on a valve seat 52a provided inside the outer cylinder 52, and a push pin 56 is mounted on the inner cylinder 53 upward by the engagement of the flange with the inner hole step. It is prevented from coming off and is slidably fitted. 45a is an inlet of the pipe 45 passing through the block 51,
Similarly, b is an exit, which is an entrance 45a and an exit 45b.
Are communicated with each other through the inner hole 52b, the inner chamber 52c, the communication hole 52d, and the passage 51, and the pressure oil flowing toward the tank 47 through the pipe line 45 passes through these passages. A compression coil spring 57 is interposed between the push pin 56 and the valve 55. The compression coil spring 57 is set so as to float the valve 55 with an extremely light pressure unless the push pin 56 is operated. There is. By pressing the push pin 56, the compression coil spring 57 is compressed, the valve 55 is pressed against the valve seat 52a, and the upper limit pressure of the pressure oil passing through the valve portion is regulated according to the pressing force of the push pin 56. It is configured to be. The pushing operation mechanism of the push pin 56 will now be described with reference to FIG. 1. The other free ends of the left and right L-shaped levers 25 and a pair of left and right pivotally mounted on the bracket 58 near the relief valves 49, 50. The free end of each L-shaped lever 59 is connected by a rod 60, an L-shaped lever 61 and a rod 62, respectively, and the other end of each L-shaped lever 59 faces above each push pin 56. When any one of the operation levers 26 is further rotated in the same direction after pressing the switch 28, the L-shaped lever 25 is rotated and the push pin 56 is pressed through the path, whereby the relief pressure is adjusted. It The positions of the pressure oil discharge ports 43 and 44 are set so that the clutch ends cutting when the pistons 32 and 33 start to open. The pressure of the pressure oil discharged is adjusted by the relief valves 49 and 50.

The operation of the steering apparatus configured as above will be described. While the machine base is moving straight, the left and right operation levers 26 are upright, the clutch surfaces 4a, 5a of both clutch gears 4, 5 and the clutch surfaces 3a, 3b of the center gear 3 are meshed, and the left and right traveling crawlers are at the same speed. Are running in. When it is desired to turn the machine base to the right, for example, when the right operation lever 26 is turned, first, the contact point of the switch 28 is closed at the initial stage of turning, and the right solenoid 31 connected thereto is connected. Sucks the sleeve and opens the right port 17b. Therefore, the pressure oil whose upper limit pressure is regulated by the main relief valve 23 passes through the port 16 on the right side and the cylinder 14 on the right side.
It is pressed in. This hydraulic pressure causes the piston 33 to move against the elastic force of the compression coil spring 35, and the piston rod 37 is pushed to rotate the foot pedal 38, so that the right clutch 3b, via the rod 40 and shifter 42,
5a is cut, and the piston 33 begins to open the pressure oil discharge port 44. By opening the pressure oil discharge port 44,
Since the pressure oil flows so as to escape toward the tank 47 through the pipe line 46 and the relief valve 50, the movement of the piston 33 stops momentarily, but if the operation lever 26 on the right side continues to rotate at this time, Since the operating lever 26 and the L-shaped lever 25 are integrally rotated, the L-shaped lever 59 presses the push pin 56. As a result, the valve 55 moves the valve seat 52a.
Since the passage of the pressure oil is regulated by being pressed to, the relief pressure is adjusted in proportion to the rotation angle of the operation lever 26. During this time, the pressure oil is continuously fed into the cylinder 14, so that the piston 33 continues to move again due to the restriction of the relief pressure, and the clutch gear 5 further moves to cause the braking surface 5b to move.
Is pressed against the brake surface 11a of the brake disk 11. Therefore, the rotation of the clutch gear 5 is braked, and the traveling crawler on the right side is decelerated or stopped via the gear 7 and the traveling drive shaft 9, so that the machine base turns to the right. Since the pressing force of the braking surfaces 5b and 11a at this time is proportional to the relief pressure, the machine base is swung according to the turning angle of the operating lever 26 with a free turning characteristic from a gentle turning to a sharp turning. be able to. The above description is for the right turn, but the same operation is performed for the left turn. When the hydraulic system fails or is otherwise necessary, the left and right foot pedals 38 can be operated to individually operate the left and right clutches and brakes.

6 to 9 show another embodiment of the present invention.
1 is a schematic side view shown in correspondence with FIG. 1, FIG. 7 is a sectional view of a hydraulic cylinder block shown in correspondence with FIG. 3, and FIG. 8 is a longitudinal sectional view of a relief valve shown in correspondence with FIG. FIG. 9 and FIG. 9 are hydraulic piping diagrams shown corresponding to FIG. The internal structure of the gear box is exactly the same as that shown in FIG. 2 of the above embodiment. The main difference between this embodiment and the above embodiment is that the relief valve provided for each cylinder 13 and 14 in the above embodiment is one relief valve shared by both cylinders 13 and 14 in this embodiment. Only the number is provided, but the difference that accompanies this will be described below. The components designated by the same reference numerals as those in the above-described embodiment have the same configuration, and the description thereof will be omitted. The left and right cylinders 13 and 14 of the hydraulic cylinder block 12A are connected to the pressure oil discharge ports 43 and 44 of the above-described embodiment at locations axially in phase by a pressure oil discharge passage 63. The outer cylinder 52 of the relief valve 49 is screwed into the central portion of the passage 63, and the space 64 below the outer cylinder 52 communicates with the pressure oil discharge pipe 63. 6
Reference numeral 5 is a pipe line that penetrates the inside of the hydraulic cylinder block 12A and connects the inner chamber 52c of the relief valve 49 and the pipe line 45 toward the tank 47. On the other hand, in the present embodiment, only one operating lever 26 is provided, which is provided in the left and right pair in the above embodiment, and the L-shaped levers 25, 61 and the rod 60 are also provided in one. A pair of switches 28A, 28B are provided on both sides of the operating lever 26 and are provided with brackets 28A, 29B.
And a lever 66 pivotally attached to the bracket 58 on the relief valve 49 side.
A pair of rods 6 are provided between the upper and lower ends of the L-shaped lever 61.
It is connected by 2A and 62B. Both the lever 66 and the rods 62A and 62B are pivotally attached by the engagement of the elongated hole and the pin. A pusher 67 is provided integrally with the support shaft of the lever 66 and pushes the push pin 56.

With this configuration, the operation lever 26
When the switch is turned clockwise in FIG. 6, first the switch 2
The contact of 8A is closed, the solenoid 31 on the right side operates, and the pressure oil is sent to the cylinder 14 on the right side to cause the piston 3 to move.
3 moves. When the piston 33 corresponds to the pressure oil discharge passage 63, the pressure oil is discharged to the tank 47 via the relief valve 49 and the pipe 45. At this time, if the operation lever 26 is further rotated in the same direction, the L-shaped lever 25 is integrally rotated and rotated clockwise, so that the rod 60, the L-shaped lever 61,
The lever 66 is rotated counterclockwise via the rod 62B and the pusher 67 pushes the push pin 56. By doing so, the machine base turns to the right, and the pressing force of the brake is adjusted by the relief valve 49, as in the previous embodiment. Even if the rod 62B is stretched and the lever 66 is rotated, the rod 62A is not stretched because the other rod 62A and the lever 66 are engaged with each other by the long holes. When the operation lever 26 is rotated counterclockwise in FIG. 6, the contact of the switch 28B is closed and the pressure oil is sent to the left cylinder 13. When the operation lever 26 is further rotated, the rod 62A pushes the lever 66 via the L-shaped lever 61 to rotate it in the counterclockwise direction, so that the pusher 67 pushes the push pin 56. As a result, the machine base turns to the left, and the pressing force of the brake is adjusted by the relief valve 49. Thus, even if one relief valve 49 is provided, the relief valve 49 operates in the same manner as in the case of two relief valves 49.

In each of the above embodiments, the switches 28, 28A, 28
Although the operation lever 26 is illustrated as an operation means of B and the relief valves 49 and 5, an operation means such as a foot pedal or a push button may be used. Further, in each of the above-mentioned embodiments, a combine harvester was exemplified as a mobile agricultural machine, but the same can be applied to other mobile agricultural machines such as a binder and a cultivator.

As is clear from the above description, according to the present invention, in the steering device for the mobile agricultural machine, the piston stroke from the clutch engagement to the clutch disengagement of the hydraulic cylinders 13 and 14 that continuously performs the cutting of the clutch and the pressing of the brake. After that, a pressure oil discharge passage is opened, and a pressure adjusting device for adjusting the pressure by operating means is provided in the pressure oil discharge passage, and the solenoid valve is opened by the operation of the operating means to send the pressure oil to the hydraulic cylinder 13 (14). After inserting and cutting the clutch, hydraulic cylinder 1
The pressure oil in 3 (14) is discharged from the pressure oil discharge port 43 (44), and the brake is pressed while adjusting the pressure with the relief valve. Since the pressure can be adjusted regardless of the pressure, the pressure setting between the clutch and the brake can be facilitated to improve the operability, and extremely excellent turning characteristics can be obtained that can be arbitrarily adjusted from a slow turn to a sharp turn. .

[Brief description of drawings]

1 to 9 show an embodiment of a steering apparatus for a mobile agricultural machine according to the present invention, FIG. 1 is a schematic side view of the same, and FIG. 2 is a longitudinal sectional view of an essential part of the gear box, and FIG. Is a sectional view of a hydraulic cylinder block, FIG. 4 is a vertical sectional view of a relief valve, FIG. 5 is a hydraulic piping diagram, FIGS. 6 to 9 show other embodiments of the present invention, and FIG. 1 is a schematic side view shown in correspondence with FIG. 1, FIG. 7 is a sectional view of a hydraulic cylinder block shown in correspondence with FIG. 3, and FIG. 8 is a longitudinal sectional view of a relief valve shown in correspondence with FIG. FIG. 9 is a hydraulic piping diagram shown corresponding to FIG. 3,4 …… Crutch gears 3a, 3b, 4a, 5a ……
Brake surface, 13, 14 ... Cylinder, 17 ... Solenoid valve, 26 ... Operating lever, 32, 33 ... Piston, 4
3,44 ... Pressure oil discharge port, 45,46 ... Pipe line, 47 ...
… Tanks, 49, 50… Relief valves, 55… Valves, 5
6 ... Pushpin.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Kenji Takahashi, No. 1 Hachikura, Tobe-cho, Iyo-gun, Ehime Prefecture, Engineering Department, Iseki Agricultural Machinery Co., Ltd. (56) 24616 (JP, Y2)

Claims (1)

[Claims] 1. A steering apparatus for a mobile agricultural machine, wherein hydraulic oil is sent to a hydraulic cylinder by opening an electromagnetic valve to continuously cut a clutch and press a brake to operate a traveling direction of a machine base. In the mobile agricultural machine, the pressure oil discharge passage is opened after the piston stroke from the clutch entry to the cut of the hydraulic cylinder and the pressure adjustment device for adjusting the pressure by operating means is provided in the pressure oil discharge passage. Steering device.