JP2006089034A - Tractor steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tractor steering device capable of omitting a hydraulic hose to couple a hydraulic cylinder with a valve and simplifying the configuration by integrating the hydraulic cylinder and a solenoid valve with a metal, and providing the metal on one side of a vehicle body on the same side as a brake pedal. <P>SOLUTION: Brake pedals 40L, 40R are arranged on one of the right and left sides of a vehicle body, and a hydraulic cylinder 14 to operate right and left brake devices 10L, 10R and a solenoid valve 13 to feed the hydraulic pressure to the hydraulic cylinder 14 are integrally constituted on a metal 48. The metal 48 is provided on one side of the vehicle body on the same side as the brake pedals 40L, 40R, and a piston 49 of the hydraulic cylinder 14 constituted on the metal 48 and the right and left brake devices 10L, 10R are mechanically and interlockingly coupled with each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a structure of a steering device for a tractor that activates a steering-side rear wheel brake during steering turning.

  Conventionally, the brake device for independently braking the left and right rear wheels and the left and right brake pedals are interlocked and connected via a rod member, and the hydraulic cylinder is driven by energizing the solenoid valve when steering the vehicle body to A tractor for operating a brake device is known.

These conventional tractor steering devices are configured such that a single-action cylinder is incorporated in each of the left and right steering brake interlocking systems, and the steering brake brakes when the cylinder is pulled. In such a configuration, the cylinders are required on the left and right sides of the vehicle body, and the hydraulic hose connecting each cylinder and the switching valve becomes long and the configuration is complicated.
Japanese Patent Laid-Open No. 4-25334

  In the present invention, the brake device (10L, 10R) for independently braking the left and right rear wheels (18, 18) and the left and right brake pedals (40L, 40R) are interlocked and connected via rod members (41L, 41R). In the steering device for a tractor that drives the hydraulic cylinder (14) by energizing the solenoid valve (13) during steering of the vehicle body and operates the braking device (10L, 10R) inside the steering, the brake pedal (40L , 40R) are arranged side by side on the left and right sides of the vehicle body, and a hydraulic cylinder (14) for operating the left and right brake devices (10L, 10R) and a solenoid valve (13) for sending hydraulic pressure to the hydraulic cylinder (14) are integrated. In general, the metal (48) is formed on one side of the vehicle body and on the same side as the brake pedal (40L, 40R). A tractor steering device characterized in that a piston (49) of a hydraulic cylinder (14) constituted by the metal (48) is mechanically linked to left and right brake devices (10L, 10R). And

  In the tractor configured as described above, when the vehicle body is steered, the hydraulic cylinder (14) is driven by energizing the solenoid valve (13), and the brake device (10L, 10R) inside the steer is operated. Further, the brake devices (10L, 10R) are operated by stepping on the left and right brake pedals (40L, 40R), respectively, regardless of the automatic operation.

  In the steering device for a tractor according to the invention, a hydraulic cylinder (14) for operating the left and right brake devices (10L, 10R) and a solenoid valve (13) for sending hydraulic pressure to the hydraulic cylinder (14) are integrated. Since the metal (48) is provided on one side of the vehicle body and on the same side as the brake pedal (40L, 40R), a hydraulic hose for connecting the cylinder and the valve is not required and the configuration is simple. Can be

  1 to 10, the tractor vehicle body can be integrated with the engine body 15, the clutch housing 16, the transmission case 17, and the like from the front, and can travel by transmitting the front wheels 4 and the rear wheels 18. It is configured. 19 is a steering handle located on the steering post 20, 21 is a cockpit, 22 is a hydraulic case for accommodating a hydraulic cylinder or the like for raising and lowering the lift arm 1 on the mission case 17, and 23 is on both left and right sides of the mission case 17. It is a rear axle housing that is positioned and integrally connected. A rear axle 24 that is interlocked with the differential of the transmission case 17 is mounted on the rear axle 24 and is transmitted to the rear wheel 18 at the outer end.

  A steering sensor 26 that detects the operating angle of the steering handle 19 is provided on the steering post 20 that supports the steering shaft 25. The steering sensor 26 includes a limit switch, and an auto brake switch 27 for automatically braking the steering brake 10, an auto lift switch 28 for automatically raising the lift arm 1, and the front wheel 4. The automatic speed increasing 4WD switch 29 and the like for automatically increasing the speed of the transmission.

  A screw portion 30 is formed on the steering shaft 25, and a screw cylinder 32 having a switch cam 31 formed thereon is screwed to the screw portion, and the switch cam 31 is moved downward by the left and right rotations of the steering shaft 25. Configured to move up. The switch cam 31 is fitted in a cam groove 33 formed along the axial direction of the steering post 20, and stops the rotation of the screw cylinder 32 to guide the vertical movement.

  The auto post brake switch 27, the auto lift switch 28, and the like are attached to the steering post 20 via a bracket 34 so that the vertical movement can be adjusted by a long hole 35 and a tightening bolt 36 inserted therethrough. Of these, the autolift switch 28 also serves as the automatic double speed four-WD switch 29.

  The auto brake switch 27 includes a left brake switch 27L (hereinafter, the components provided in a pair of left and right are described with the left side being L and the right side being R, respectively), but below the auto lift switch 28. Yes, when the right brake switch 27R is in an upper position symmetrical to this, and the switch roller 37 is positioned on the convex portion of the switch cam 31, the switch is turned on, and the concave portion is turned off. Among these, in the recess 38 in the middle of the switch cam 31, an appropriate interval is formed between the steering sensor 26 and the switch roller 37, and this cam interval portion K becomes a play for turning the steering shaft 25. The steering operation at the interval K does not reach the turning operation area.

  These switches 27L, 27R, 28 may be arranged on the same axial direction line, but may be arranged by shifting the phase around the axis to form a switch cam 31 for each switch. Each switch 27L, 27R, 28 is moved up and down within the range of the long hole 35 with respect to the bracket 34 by loosening the bolt 36, thereby adjusting the switch ON position, the ON interval between the switches, and the like. Can do.

  Each of the auto brake switches 27L and 27R and the auto lift switch 28 operate the solenoid valves 13L and 13R of the hydraulic circuit through the controller 39. The solenoid valves 13L and 13R of the hydraulic circuit can push and pull the push-pull cylinder 14 to brake the left steering brake 10L or the right steering brake 10R. 40L and 40R are petals for operating the left and right steering brakes 10L and 10R. 41L and 41R are brake rods interlocking with the left and right steering brakes 10L and 10R. The brake rods 41L and 41R are connected to the brake arms 43L and 43R on the arm shaft 42 so that the brake rods 41L and 41R can be operated by the brake petal 40L (40R), and also can be operated by the push-pull cylinder 14. Yes.

  The rod-shaped arm shaft 42 is rotatable with respect to a pipe 44 penetrating the clutch housing 16, and a pair of left and right brake arms 43L and 43R are mounted on one end thereof. The brake arm 43L for braking and interlocking the left steering brake 10L can be rotated integrally with the arm shaft 42 and the pin 45, and a brake petal 40L provided on the coaxial 44 so as to be rotatable is in contact with the brake arm 43L. Accordingly, the pin 46L of the brake arm 43L can be engaged and rotated. Reference numeral 47 is an arm integrated with the tip of the arm shaft 42 and connects the left rod 41L.

  Further, the right brake arm 43R and the brake petal 40R are rotatable with respect to the arm shaft 42. By stepping on the right brake petal 40R, the pin 46R is engaged to rotate the brake arm 43R, and the rod 41R is moved. The steering brake 10R is interlocked with the brake.

  The solenoid valve 13 and the push-pull cylinder 14 are provided on an integrally configured metal 48 and attached to the side surface of the clutch housing 16. The piston 49 of the push-pull cylinder 14 is integrally provided with bifurcated arms 50L and 50R, and the brake arms 43L and 43R are brought into contact with the adjustment bolts 51L and 51R at the tips of these arms 50L and 50R. At the neutral position N of the piston rod 49, both the left and right brake arms 43L, 43R are not rotated and are in the non-braking position. When the piston rod 49 is pushed out from the neutral position N, the bolt 51R is moved to the right brake arm. 43R can be pushed and rotated to brake the right steering brake 10R. When the piston rod 49 is retracted from the neutral position N, the bolt 51L pulls the left brake arm 43L and the left steering brake 10L. Brake.

  The push-pull cylinder 14 and the piston 11 for braking the steering brake 10 are composed of large-diameter and small-diameter pistons 51 and 52 and cylinders 53 and 54 for fitting them, and the small-diameter piston 52 is a piston. The rod 49 is integrated, and the head 55 is fitted into the center of the large-diameter donut-shaped piston 51, and the arm 50 is attached to the tip. The cylinder 53 on the head side of the push-pull cylinder 14 has a port 12R for interlocking the right steering brake 10R, and the cylinder 54 on the opposite side is interlocked with the left steering brake 10L. The tank port T is formed at the step between the cylinders 53 and 54.

  The solenoid valve 56 performs expansion / contraction control of the lift cylinder 57 in the hydraulic case 22, and thereby the lift arm 1 that connects the work implements is raised and lowered. The solenoid valve 6 switches the front wheel transmission clutch 5 provided in the middle of the transmission shaft that is linked from the transmission case 17 to the differential device 58 of the front wheel 4 through the clutch housing 16 and rotates the front wheel 4. It is possible to change gears by switching between constant-speed four-wheel drive that is transmitted at substantially the same speed as the rear wheel 18 and speed-up four-wheel drive that speeds up the rotation of the front wheel 4 approximately twice that of the rear wheel 18.

  By switching the solenoid valves 56 and 6 almost simultaneously by turning on the auto lift switch 28, the lift arm 1 is raised, and the constant speed four-wheel drive is switched to the four-speed four-wheel drive to speed up the transmission of the front wheels 4. To. At the same time or after the auto lift switch 28 is turned on, the auto brake switch 27L or 27R is turned on, and the steering brakes 10L and 10R are braked on the rear wheel 18 on the steering side.

  Reference numeral 59 denotes a sensitivity adjustment dial, which adjusts the detection sensitivity of the switches 27 and 28. A steering speed sensor 60 detects the rotational speed of the steering shaft 25 by the steering handle 19.

  In the hydraulic circuit for controlling the lift cylinder 57, the push-pull cylinder 7, the push-pull cylinder 14, the rolling cylinder 61 and the like of the front wheel transmission clutch 5, the steering sensor 19 is operated by turning the steering handle 19 as described above. 26, the work machine is raised, the front wheel 4 is accelerated, and the steering brake 10L or 10R is braked, and the pressure reducing valve 3 is provided to switch the solenoid valve 6 of the front wheel transmission clutch 5. When the steering brakes 10L and 10R are operated by operating the pressure-compensated secondary pressure to the steering push-pull cylinder 14 and the solenoid valves 13L and 13R, the front wheel transmission clutch 5 is disconnected due to a decrease in oil pressure, Also, the steering brakes 10L and 10R and the front wheel shift clutch are driven by the oil pressure increase. But there is no malfunction, such as work at the same time.

  The operation of the piston 11 in the push-pull cylinder 14 will be described with reference to FIGS. 1 and 8 to 10. In the piston 11, assuming that the effective cross-sectional area is set such that the large-diameter piston 51> the small-diameter piston 52> the head 55, the total pressure is applied to both the ports 12 </ b> L and 12 </ b> R by turning off the solenoid valve 13. As shown in FIG. 8, the piston 51 is pushed and locked to the stepped portion, and the piston 52 is pushed and locked to the piston 51 side to be in the neutral position. Reference numeral 67 denotes a clip ball for locking the neutral position N.

  When the solenoid valve 13R is turned ON, the port 12R becomes full pressure and the port 12L becomes no pressure. For this reason, as shown in FIG. 9, the piston 51 is pushed until it is locked to the step portion, and the head portion 55 is pushed in the same direction, so that the right steering brake 10R is interlocked and braked.

  Further, when the solenoid valve 13L is turned ON and the port 12L becomes full pressure and the port 12R becomes no pressure, the piston 52 is pushed toward the cylinder 53 side while the piston 51 is engaged as shown in FIG. Press against the cylinder cap 66. This interlocks the right steering brake 10L.

  In the hydraulic circuit, P1 is a main pump, P2 is a sub pump, and T is a tank port. 62 is a relief valve, 63 is a flow dividing valve, and 64 is a rolling control valve for the rolling cylinder 61 that performs rolling control of the work machine. Reference numeral 65 denotes a power steering hydraulic circuit, which increases the rotational force operated from the steering shaft 25 by the hydraulic pressure to interlock the steering of the front wheels 4.

  The hydraulic circuit shown in FIG. 11 shows the configuration of another embodiment of the present application, in which the pressure oil supplied to the push-pull cylinder 14 is replaced with the solenoid valve 13 of the push-pull cylinder 14 that interlocks the steering brake 10. Normal open type proportional pressure reducing valves 68L and 68R to be controlled are provided. When no current is passed through both of these proportional pressure reducing valves 68L and 68R, the left and right ports 12L and 12R are at the same pressure and are forced to the neutral position N.

  When the left or right proportional pressure reducing valve 68L or 68R is energized, the oil pressure changes according to the current value, and the piston 11 is shifted to the left and right. Since the oil pressure at this time can be changed and adjusted, the braking force corresponding to the traveling speed can also be controlled.

  The side views shown in FIGS. 12 and 13 show another embodiment around the arm shaft 42, and the steering brakes 10L and 10R are interlocked by the brake petals 40L and 40R and the piston rod 49 of the push-pull cylinder 14. In order to simplify the mechanism, a pin 69 is fixed instead of the arm 50 in FIGS. 6 and 7, and the brake arm 43R and the arm 76 pivotally supported around the arm shaft 42 are opposed to the front and rear of the pin 69, Between the brake arm 43R and the arm 76, pivots 77, 75 are supported by links 74, 75 pivotally supported by pins 73 fitted in guide grooves 71 formed on a bracket 70 fixed to the side surface of the clutch housing 16. 78. The steering brakes 10L and 10R by the brake petals 40L and 40R and the push-pull cylinder 14 can be braked independently.

Hydraulic circuit diagram. The side view of a steering shaft part. A partial enlarged side view and a block diagram thereof. The top view of a tractor. The side view. The disassembled perspective view and top view of the operation mechanism of a steering brake. The side view. The expanded sectional view of the push pull cylinder part for steering brakes. The operation diagram. The operation diagram. FIG. 6 is a hydraulic circuit diagram showing a part of another embodiment. The side view of the operation mechanism of the steering brake which shows a partially different Example. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lift arm 2 Main hydraulic circuit 3 Pressure reducing valve 4 Front wheel 5 Front wheel transmission clutch 6 Solenoid valve 7 Push cylinder 8 Front wheel transmission hydraulic circuit 9 Secondary pressure circuit 10 Steering brake 11 Piston 12 Port 13 Solenoid valve 14 Push pull cylinder 18 Rear Wheel 40L Brake pedal 40R Brake pedal 41L Rod member 41R Rod member 48 Metal 49 Piston

Claims (1)

The brake devices (10L, 10R) for independently braking the left and right rear wheels (18, 18) and the left and right brake pedals (40L, 40R) are interlocked and connected via rod members (41L, 41R), and the vehicle body is controlled. In the steering device for a tractor that drives the hydraulic cylinder (14) by energizing the solenoid valve (13) during operation and operates the brake device (10L, 10R) inside the steering, the brake pedal (40L, 40R) is Provided side by side on the left and right sides of the vehicle body, a hydraulic cylinder (14) for operating the left and right brake devices (10L, 10R) and a solenoid valve (13) for sending hydraulic pressure to the hydraulic cylinder (14) are integrally made of metal ( 48) and this metal (48) is provided on one side of the vehicle body on the same side as the brake pedal (40L, 40R), Tal (48) to the piston (49) and the respective right and left brake device for a hydraulic cylinder (14) configured (10L, 10R) and the steering device of a tractor, characterized in that the mechanically interlocking connecting.

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