JPH07257414A - Supporting structure for steering cylinder - Google Patents

Abstract

PURPOSE:To simplify fitting structure of a steering cylinder and make it compact and provide a simple assembling in a power steering disposed a both rod type steering cylinder in a front axle case. CONSTITUTION:A front axle case is adapted to be a trisected structure comprising a center case 1M and left and right axle cases 1L.1R and a steering cylinder is enclosed in the center case and a cyclic projecting portion 25 is fixed on an outer periphery of a cylinder tube of the steering cylinder and its opposing two inside faces 25a is contacted on an outside face of the center case and faucet holes 1b.1b are mounted in the left and right axle cases 1L.1R and the cyclic projecting portions 25.25 are inserted and supported. A rotational movement of the cylinder tube is prevented by adapting the faucet holes being larger diameter larger than a projecting circumscribing circle of an hydraulic passage boss 10d mounted axially at both sides of the cylinder tube and providing a boss 24 having a holding hole in an outer periphery portion of the steering cylinder and engaging with the holding tool 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for mounting a cylinder for power steering in a tractor.

[0002]

2. Description of the Related Art Conventionally, a power steering system has been known in which a double rod type steering cylinder is supported by a front axle case, and a steering rod is rotated by sliding a piston rod of the steering cylinder. For example, it is a technique described in Japanese Patent Laid-Open No. 4-358964.

[0003]

In such a conventional power steering cylinder mounting structure, since the steering cylinder is not completely housed and mounted in the axle case, there are many irregularities and gaps in the appearance, which results in dust. It is easy to attach dirt, mud, etc., and it causes rust, so maintenance is poor and it took time to wash the car. Furthermore,
When the steering cylinder fixed part is not sealed, foreign matter such as dust and mud adheres to the operation, so that each fixed part is easily worn, the play of the steering link part increases, and the steering operability deteriorates. Safety was reduced. Also, if the steering cylinder is provided outside the axle case, a gap with the wall of the case is created, and the axle case becomes large, and the front-rear length of the support portion becomes long.

[0004]

The present invention uses the following means in order to solve the above problems. That is, in a power steering in which a steering system of both rod type is supported by a front axle case for steering, the front axle case has a three-part structure of a center case and left and right axle cases, and a steering cylinder is included in the center case. An annular convex portion is fixedly provided on the outer circumference of the cylinder tube of the steering cylinder, and two inner side surfaces of the annular convex portion that face each other are brought into contact with the outer surface of the center case to position them in the axial direction. An inlay hole is provided, and an annular convex portion is inserted into and supported by the inlay hole for positioning and fixing in a direction perpendicular to the axis of the steering cylinder, and the inlay hole is provided on both sides of the cylinder tube in the axial direction of an oil passage boss. The diameter is larger than the projected circumscribed circle, and it is included in the center case. A boss having a locking hole in the steering cylinder outer peripheral portion provided that is obtained by preventing the rotation of the cylinder tube engaging the locking member into the locking hole of the boss.

[0005]

By using such means, when the steering cylinder 10 is incorporated in and supported by the front axle case, the inner side surfaces 25a, 25 of the annular projections 25, 25 fixed to the cylinder tube 10b are opposed to each other.
The a is in contact with the side surfaces on both sides of the center case 1M to be positioned in the left-right (axial center) direction.
5 is a spigot hole 1b for the left and right axle cases 1L and 1R
・ It is inserted and fixed in 1b, and the steering cylinder 10 is positioned in the front-back direction.
The cylinder tube 10b is prevented from rotating by inserting the locking tool 21 into the locking hole 24a of the boss 24 fixed to the outer periphery of the cylinder tube 10b from the outside of the vehicle, and the outer periphery of the steering cylinder 10 is covered by the front axle case 1. To be done.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the structure of one embodiment of the present invention will be described in the case of a tractor as a traveling vehicle shown in the accompanying drawings. Fig. 1 is a front view of front wheels and front axle case, Fig. 2
2 is a front sectional view of the front axle case, FIG. 3 is a sectional view taken along the line XX in FIG. 2, and FIG. 4 is a sectional view taken along the line YY in FIG.

In FIG. 1, a front axle case 1
Is divided into three parts, and is composed of a center case 1M in the center, a left axle case 1L and a right axle case 1R protruding to both sides of the center case 1M, which are fixed on both sides of the center case 1M by bolts 6 ... The axle case 1 is supported so as to be able to swing left and right with respect to an axle frame 2 which constitutes a body frame, and as shown in FIG. 4, a pivot pin 1a is provided at a center front end of a center case 1M.
And a rear portion of the center case 1M is rotatably supported by a bracket 4 depending from the axle frame 2 via a bearing 7.

In the center case 1M, a steering cylinder 10 for power steering, which will be described later, is installed horizontally in the left and right directions.
Is a double-acting double-rod cylinder in which the piston rods 10a and 10a are projected to both sides.
The tip ends of 0a and 10a are connected to tie rods 12 and 12 through spherical joints 11 and 11, respectively.
The other end of 12 is connected to the knuckle arm 13. The knuckle arms 13, 13 are connected to a rotating case 20 that pivotally supports the front wheels 9, 9 and are rotatable about a kingpin that supports the rotating case 20 by sliding the piston rods 10a, 10a left and right. The front wheels 9, 9 can be turned to the left and right to be steered.

The center case 1M also serves as a front differential case. As shown in FIGS. 2 and 4, a front wheel drive shaft protruding forward from a rear transmission case (not shown) is connected to the center case 1M via a universal joint. Power is transmitted to the input shaft 14 that is rotatably supported, and a pinion gear 14a is formed at the front end of the input shaft 14. The pinion gear 14a is rotatably mounted on the left and right axle cases 1R via bearings. The ring gear 15 is meshed with the supported ring gear 15, and the ring gear 15 is fixedly mounted on the differential gear case 16. In the ring gear 15 and the differential gear case 16, two sets of bevel gears 17, 17, 18, 18 are provided.
Are rotatably meshed and housed to form a differential device, and the left and right front transmission shafts 19, 19 are connected to the left axle case 1L,
The bevel gears 18 and 18 are fixedly installed at one end of the right axle case 1R, and the other end is inserted into the rotating case 20 and 20 to drive the front wheels 9 and 9 via gears or the like. It is possible.

As shown in FIGS. 2, 3 and 4, the steering cylinder 10 of the present invention is provided horizontally on the front part of the front axle case 1, and the steering cylinder 1
0 is configured symmetrically, cylinder tube 1
A boss 24 is fixed to the center of the outer periphery of 0b.
4. A locking hole 24a is provided at the center, while an insertion hole is opened in the central upper surface of the center case 1M in alignment with the position of the locking hole 24a, and the locking tool 21 fits the sealing material 22 onto the outside. From the center case 1M to the center (radial direction)
The cylinder tube 10b is fixed by being inserted into the locking hole 24a. In this embodiment, the locking tool 21 is a bolt and is screwed and fixed to the center case 1M. In addition, although the boss 24 is one in this embodiment, two or more bosses 24 may be formed so as to be fixed at several places, and even the positions of the boss 24 and the insertion hole of the locking tool 21 are the same. The position is not limited to the left and right center position.

Ring-shaped annular projections 25, 25 are fixedly installed on the outer circumference of the cylinder tube 10b at symmetrical positions in conformity with the positions of both side surfaces of the center case 1M, and the annular projections 25, 25 oppose each other. At the time of assembly, the inner side surfaces 25a, 25a are brought into contact with the outer side surface of the center case 1M for axial positioning. And
A sealing material insertion groove is formed on the outer periphery of the annular projections 25, 25, and the sealing materials 23, 23 are fitted to the annular projections 2.
5.25 is inserted and fixed in the spigot holes 1b and 1b of the left and right axle cases 1L and 1R, positioned in the direction perpendicular to the axis, and sealed.

Oil passage bosses 10d and 10d are provided on both ends of the cylinder tube 10b so that the circumscribed circle diameter of the oil passage boss 10d is shorter than the diameter of the inlay hole 1b, that is, the axial center. The circumscribed circle of the projected shape in the direction is made smaller than the pilot hole 1b, and the left and right axle cases 1b
The steering cylinder 10 is supported by L and 1R. Then, the oil passage bosses 10d, 10d are connected to a steering control valve through a pipe (not shown), and when pressure oil is sent to one of the oil passage bosses 10d, the piston 1
0c is pushed to slide the piston rods 10a and 10a.
Is slid to the left and right.

In such a structure, when the steering handle of the machine is rotated during traveling, the steering control valve is switched and pressure oil is sent to one side, so that the oil passage boss 10 is supplied.
Oil is fed into the cylinder tube 10b from d and pushes the piston 10c to slide the piston rod 10a, and the spherical joint 11, the tie rod 12, the knuckle arm 1
Steering is performed by rotating the front wheels 9 and 9 through 3.

[0014]

The present invention having the above-mentioned structure has the following effects. That is, since it is configured as in claim 1, by fixing the central part of the steering cylinder by enclosing and fixing it in the axle case, unevenness on the outer shape is reduced, dust and dirt are less likely to adhere, and durability is improved. The safety and reliability of the steering operation can be improved, the maintainability can be improved, and the car can be easily washed. Also, just by fixing the annular convex part to the cylinder tube,
Left and right positioning is possible and the increase in parts is minimized, so the increase in weight is minimal, the front-rear length of the axle case can be shortened, and the size can be reduced at the same time.

According to the second aspect of the present invention, the steering cylinders can be supported by the left and right axle cases while positioning in the front-rear direction, and the inlay hole serving as the supporting portion is an obstacle when the oil passage boss is inserted and assembled. do not become. Further, according to the third aspect of the invention, since the locking tool can be locked by simply inserting the locking tool from the outside of the center case into the locking hole of the boss on the steering cylinder, the boss is exposed to the outside of the axle case. Since it is not present, the appearance was also clean, and the detent could be constructed at a low cost with a simple configuration.

[Brief description of drawings]

FIG. 1 is a front view of front wheels and a front axle case.

FIG. 2 is a plan sectional view of a front axle case.

FIG. 3 is a sectional view taken along the line XX in FIG.

FIG. 4 is a sectional view taken along the line YY in FIG.

[Explanation of symbols]

 1 Front Axle Case 1M Center Case 1L Left Axle Case 1R Right Axle Case 1b Inlay Hole 10 Steering Cylinder 10a Piston Rod 10b Cylinder Tube 10d Oil Path Boss 21 Locking Tool 24 Boss 24a Locking Hole 25 Annular Convex 25a Inner Side

Claims (3)

[Claims] 1. In a power steering system in which a steering system of a double rod type is supported by a front axle case for steering, the front axle case has a three-part structure of a center case and left and right axle cases, and a steering cylinder is provided in the center case. It is characterized in that an annular convex portion is fixedly provided on the outer circumference of the cylinder tube of the steering cylinder, and two inner side surfaces of the annular convex portion that oppose each other are brought into contact with the outer surface of the center case for axial positioning. Steering cylinder support structure. 2. Right and left axle cases are provided with spigot holes, and annular convex portions are inserted into and supported by the spigot holes for positioning and fixing in a direction perpendicular to the axis of the steering cylinder, and the spigot holes are provided on both sides of the cylinder tube. The support structure for a steering cylinder according to claim 1, wherein a diameter of the oil passage boss provided is larger than a projected circumscribing circle in the axial direction. 3. A boss having a locking hole is provided on an outer peripheral portion of a steering cylinder included in a center case, and a locking tool is engaged with the locking hole of the boss to prevent rotation of the cylinder tube. The support structure for a steering cylinder according to claim 1 or 2, characterized in that.