JPS6132819Y2 - - Google Patents

Description

[Detailed description of the invention] As shown in Fig. 2, the axle 2' that drives the front wheels of a conventional four-wheel drive agricultural tractor or the like can swing around king pins 5' and 6' by an angle corresponding to the steering angle. In addition, since it is necessary to obtain uniform rotation of the wheels during steering, a cross universal joint or a constant velocity universal joint 1' is used as the steering joint of the drive shaft. In addition, since agricultural tractors require sufficient ground clearance and a large traction force, a final reduction gear using gears 3' and 4' is installed between the universal joint 1' and the axle 2'.
Generally, the height of the axle body 7' above the ground is determined by the axial distance C between the two gears, and the strength of each part is ensured by appropriately selecting the reduction ratio.

However, even if either a cruciform universal joint or a constant velocity universal joint is used as the drive shaft joint of the steering section, the maximum steering angle is about 40 degrees, and beyond that, constant speed rotation of the axle cannot be obtained and small turns cannot be achieved. There is a drawback.

It is already known that a group of bevel gears around the vertical axis is used as a power transmission means to solve this drawback. Simply connecting the movable cases of the steering system so that they can be steered around the vertical king pin axis interposed between the opposing surfaces of both cases would cause the movable cases to become distorted and smooth steering would not be possible. It has been proposed that the fixed case be connected to a king pin on the upper part of the fixed case via a connecting member, thereby supporting it via two king pins, upper and lower.

However, when installing the connecting member, if the facing surface of the connecting member is brought close to the outer wall of the fixed case in a parallel state so as to move away from the wheels, the mud that has entered the space facing the connecting member and the outer wall of the fixed case is compressed and becomes movable. The problem of obstructing steering of the case is a new drawback in that it is always located inside the wheels and is steered along with the wheels, making visual inspection difficult.

In order to eliminate these drawbacks, the present invention is designed to connect the movable case of the steering system that supports the wheel mounting shaft to the upper part of the fixed case that is spaced apart in the height direction via a connecting member, allowing stable operation of the movable case without any difficulty. In addition, a space is formed on the facing surface of the connecting member to prevent the movable case from prying and the outer wall of the fixed case, which is narrow at the top and wide at the bottom, to prevent compaction of mud in the facing space. When the connecting member that prevents the movable case from being twisted faces the outer wall of the fixed case,
Furthermore, it is an object of the present invention to provide a steering device for an agricultural four-wheel drive vehicle which also serves to prevent mud from being compressed in the opposing space, and which allows the movable case to be easily steered without mud clogging. be.

Now, the construction of the present invention will be described with reference to an embodiment shown in the drawings. Reference numeral 1 denotes a drive shaft which is rotatably supported horizontally within an axle body 8 by bearings 11 and other structures (not shown). Reference numeral 2 indicates a wheel mounting shaft, and this wheel mounting shaft 2 is attached to a bearing case 10 that projects so as to mesh with a bevel gear 5 of the intermediate shaft 7 on the wheel side with respect to the center of the vertical intermediate shaft 7, which will be described later. It is rotatably suspended horizontally via bearings 14 and 15. Reference numeral 3 denotes a bevel gear which is attached to the drive shaft 1 by means of splines or the like so as to be capable of transmitting power, and 4 denotes a bevel gear that engages with the bevel gear 3 and is formed integrally with the axle body 8 at both ends of the axle body 8. The intermediate shaft 7 is installed with a spline or the like on the upper part of the intermediate shaft 7 which is vertically mounted in the fixed case 22 with the upper part tilted inward and away from the wheel side. It is provided so as to share the same axis as the king pins 30 and 31 protruding from the upper and lower ends, respectively.

Reference numeral 5 denotes a transmission case 9 rotatably connected to a king pin 31 protruding from the lower part of the fixed case 22 by fitting a support provided at the upper part thereof, and an opening formed on the wheel side of the transmission case 9. A bevel gear for driving a wheel mounting shaft is attached to the lower part of the intermediate shaft 7 by a spline or the like in a movable case 23 consisting of a bearing case 10 that is installed so as to close the bearing case 10. It engages with the driven bevel gear 6 fixed to the mounting shaft 2 with a spline, a washer 20, and a nut 21 to form a pair. 1
2 and 13 are bearings that support the intermediate shaft 7; 16 are thrust bearings that support the weight of the vehicle on the axle; 17;
Reference numeral 18 indicates a king pin bearing, and reference numeral 19 indicates an oil seal for preventing leakage of lubricating oil stored inside the transmission case 9.

The movable case 23 is located below the fixed case 22 and rotates around the axis of the king pin 31.
Further, the bearing case 10 is located below the king pin 31 position and is located substantially on the axis of the wheel mounting shaft 2 that protrudes toward the wheel side from the axis of the intermediate shaft 7.
The intermediate part is formed integrally with the outer wall of the intermediate shaft 7.
A king pin support portion provided at the upper end of the connecting member 24 is inserted into the king pin 30 above the fixed case 22 spaced apart in the height direction via the connecting member 24 which is inclined approximately along the axial direction of the inclined axis. At the very least, the bearing case 10 and the transmission case 9 are integrally assembled with bolts or the like so that they are supported by the fixed case 22 at two locations, upper and lower, which are widely separated in the vertical direction. The wheel mounting shaft 2 is configured to be able to swing integrally with the movable case 23.

The connecting member 24 that connects the fixed case 22 and the movable case 23 has an intermediate portion at the upper and lower ends inclined approximately along the inclination direction of the intermediate shaft 7, and the wheels of the fixed case 22 that the connecting member 24 faces. The side outer wall is formed as an inclined wall surface that approaches the axis of the intermediate shaft 7 as it goes downward, and a space is formed on the opposing surface between the connecting member 24 and the wheel side outer wall of the fixed case 22, which is narrow at the top and wide at the bottom. Configure Y.

Therefore, even if the wheels are steered, the wheel side of the fixed case 22 is always separated from the wheels by the connecting member 24, and mud scattered by the rotation of the wheels can enter the fixed case 22 side. prevent this from happening. Furthermore, even if mud that could not be prevented by the connecting member 24 invades the fixed case 22 side, this space Y prevents the mud that has invaded into the space Y from being prevented by the narrow upper space. This combination of the fact that the fall into the space is promoted and the large space below allows for easy escape and prevention of compaction prevents the compaction of the mud across the opposing front surfaces in the vertical direction, allowing the connection to move even further. Member 24
As the mud is scraped off by the rotation of the
The movable case 23 can be easily steered due to the absence of compressed mud in the space Y facing the two, so it is always located inside the wheel and is blocked by the wheel and cannot be seen from the outside of the wheel. By preventing mud from clogging between the connecting member 24, which is steered along with the wheels on the outside and is difficult to see from inside the wheels, and the fixed case 22, the opposing spaces between the two are arranged in parallel with narrow intervals. The problem with this method is that the mud that has entered a narrow space is compressed in the space because there is no space for it to escape, and the opposite space is clogged with compressed mud that makes it difficult to maneuver the movable case. It can be prevented.

Therefore, the power and angular velocity transmitted to the drive shaft 1 are transmitted to the intermediate shaft 7 via the bevel gears 3 and 4, and further transmitted to the wheel mounting shaft 2 via the bevel gears 5 and 6. In this device, bevel gears 3, 4 and bevel gear 6,
By appropriately selecting the tooth number ratio of 6, the necessary reduction ratio can be obtained.

Further, by appropriately selecting the crossing angle of the bevel gears 3 and 4, the necessary kingpin angle can be obtained, and if the same thing is done for the bevel gears 5 and 6, the necessary camber angle can be obtained. Also, the drive shaft 1 and the wheel mounting shaft 2
The required ground clearance can be easily obtained by changing the axial center spacing h.

To explain the swinging of the movable case 23 and the power transmission when the movable case 23 swings, the movable case 23 on which the wheel mounting shaft 2 is supported is connected to the fixed case 22 at a distance in the height direction. Although the fixed case 22 is unstable due to
Since the wheel is supported at two locations, upper and lower, which are spaced apart in the height direction, the wheel can be swung by any desired angle around the king pins 30 and 31 without being twisted, and the wheel mounting shaft 2 will come to the position 2a. However, the meshing conditions do not change at all, power and angular velocity can be transmitted, and a constant wheel rotational speed can be obtained regardless of the magnitude of the steering angle.

In short, the present invention disposes a vertical intermediate shaft between a horizontal drive shaft and a wheel mounting shaft, and drives the wheel mounting shaft from the drive shaft via bevel gears fixed to each shaft. In the steering device, a movable case for supporting the lower part of the intermediate shaft is connected below a fixed case for supporting the upper part of the intermediate shaft so as to be steerable around the axis of the intermediate shaft, the movable case comprising: The wheel mounting shaft that meshes with the bevel gear of the intermediate shaft is protruded toward the wheel side so as to support the wheel mounting shaft on the wheel side from the center of the intermediate shaft, and the high The space is connected to the center axis of the upper part of the fixed case that is spaced apart in the horizontal direction, and a space is formed on the opposing surface between the connecting member and the outer wall on the wheel side of the fixed case, which is narrow at the top and wide at the bottom. The movable case is connected to the upper part of the fixed case that is spaced apart in the height direction by using a connecting member located above the wheel mounting shaft that protrudes toward the wheel side from the axis around the vertical axis, and the movable case itself can be moved up and down. By supporting the movable case in two places, stable steering can be performed without twisting, but the connecting member that prevents twisting of the movable case is a partition between the wheels and the fixed case. This prevents mud scattered by the wheels from entering the fixed case side.
Furthermore, by forming a space that is narrow at the top and wide at the bottom on the facing surface of the connecting member and the fixed case outer wall in a configuration facing the outer wall of the fixed case, it is possible to promote the fall of mud into the wide space below. In addition to preventing the compression of mud in the space, it also serves to prevent the compression of mud over the entire opposing surface in the vertical direction when mud enters the fixed case side beyond the connecting member.
By preventing mud from clogging between the fixed case and the connecting member, which is normally located inside the wheels and is steered along with the wheels, making visual inspection difficult, the movable case can be easily steered without mud clogging. It has many practical effects.

[Brief explanation of the drawing]

Figure 1 is a schematic side view of a conventional agricultural four-wheel drive vehicle.
Fig. 2 is a cutaway side view of the wheel mounting shaft of the four-wheel drive steering device, Fig. 3 is a cutaway side view of the wheel mounting portion of the four-wheel drive steering device according to the present invention, and Fig. 4 is a cutaway side view of the wheel mounting shaft of the four-wheel drive steering device. FIG. 3 is a plan view showing a swing range. 1' is a constant velocity universal joint, 2' is an axle, 3', 4' are reduction gears, 5', 6' are king pins, 1 is a drive shaft, 2
is the wheel mounting shaft, 3, 4, 5, 6 are bevel gears, 7 is the intermediate shaft, 8 is the axle body, 9 is the transmission case, 10 is the bearing case, 11, 12, 13, 14, 15 are the bearings, 16 is the Thrust bearing, 17 and 18 are king pin bearings, 19 is an oil seal, 20 is a washer, 21
is a nut, 22 is a fixed case, 23 is a movable case, 24 is a connecting member, 30 and 31 are king pins,
Y is space.

Claims (1)

[Scope of utility model registration request] A longitudinal intermediate shaft is disposed between the horizontal drive shaft and the wheel mounting shaft, and the drive shaft drives the wheel mounting shaft via bevel gears fixed to each shaft. A steering device in which a movable case supporting a lower part of an intermediate shaft is connected below a fixed case supporting an upper part of the intermediate shaft so as to be steerable around the axis of the intermediate shaft,
A connection in which the movable case is positioned above the wheel mounting shaft of the movable case by protruding toward the wheel side so as to support a wheel mounting shaft meshing with a bevel gear of the intermediate shaft on the wheel side with respect to the axis of the intermediate shaft. The upper part of the fixed case is connected to the center axis of the intermediate shaft separated in the height direction via a member, and a space is formed on the opposing surface between the connecting member and the wheel-side outer wall of the fixed case, which is narrow at the top and wide at the bottom. A steering device for agricultural four-wheel drive vehicles featuring: