JPH0747390B2 - Steering device for passenger work machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement in a steering device for a riding work machine.

(Prior Art) Conventionally, as described in, for example, Japanese Patent Laid-Open No. 61-175173, as a steering device for a passenger work machine, it is connected to a steering shaft (27) so as to be interlocked with steering of a steering handle (19). The relay gear case (18) and the universal joint (3
Two relay steering shafts (3
2), (33) and the relay steering shafts (32), (3)
3) is connected to the relay gear case (18) so that the driving force of the relay gear case can be transmitted, and the front wheels disposed on both outer side portions in front of the frame (15) extending in the front-rear direction of the vehicle body can be steerably connected. A steering gear box (31) is also known.

Here, the relay gear case (18) is a frame (15).
The steering gear box (31) is arranged at an inner position of the frame (15) while the steering gear box (31) is arranged at an outer position in front of a mission system arranged at the rear of the frame. The steering shafts (32) and (33) project outward from one side of the frame (15).

(Problems to be solved by the invention) However, the two relay steering shafts (32),
If the configuration is such that (33) is projected outward from one side of the frame (15), the steering handle (19) can be moved in a predetermined direction.
That is, when the steering wheel is steered clockwise in FIG. 1 of the above-mentioned publication, one end portion of the front wheel (12) may interfere with the relay steering shafts (32), (33),
There was a problem that the maximum steering angle of the steering wheel (19) corresponding to the maximum allowable steering angle of the front wheels (12) could not be obtained.

Further, as described above, the relay steering shaft is made up of two members (32) and (33), and these image members (3
Since it is necessary to connect 2) and (33) with the universal joint (36), there is a problem that the number of parts increases.

(Means for Solving Problems) In order to solve the above problems, the present invention extends in the front-rear direction of the vehicle body, mounts the engine unit 5 substantially above the center, and rearwardly to the mission system. Frame 1 with 8
The relay gear case 14 connected to the steering shaft 13 so as to be interlocked with the steering of the steering handle 10, the relay steering shaft 15 connected to the relay gear case 14, and the relay gear case connected to the relay steering shaft 15. A steering gear box 17 which is connected to transmit the driving force of 14 and which steerably connects the front wheels 22, 22 'arranged on both outer side portions of the frame 1 to either the left or right side of the frame 1. It is characterized in that the steering wheel 10 is set at a position near one side along the front-rear direction of the vehicle body, and the maximum steering angle of the steering handle 10 can be set to be larger than that of the conventional configuration. Steering wheel for passenger working machine in which the relay steering shaft 15 connecting the steering gear box 17 and the steering gear box 17 can be constituted by one member. And its object is to provide a device.

(Operation) When the steering wheel 10 is steered, the driving force by the steering is transmitted via the steering shaft 13 to the relay gear case.
14 is transmitted to the relay gear case 14
Is transmitted to a steering gear box 17 via a relay steering shaft 15 having one end connected to the front wheels 22, 22 ′ according to the driving force transmitted to the steering gear box 17.
In this case, since the relay gear case 14, the relay steering shaft 15, and the steering gear box 17 are arranged inside the frame 1, at least in the range of the maximum steering angle of the steering handle 10. The front wheels 22, 22 'never come into contact with the relay gear case 14, the relay steering shaft 15 and the steering gear box 17.

(Embodiment) An embodiment of the present invention will be described below with reference to the accompanying drawings.

As shown in FIGS. 1 to 3, a frame 1 extends in the front-rear direction of the vehicle body. The frame 1 includes a front frame 2 to which a bumper (not shown) is attached, and left and right sides of the front frame 2. The left side frame 3 and the right side flume 3 ′, which are connected and fixed to both ends and are formed in a substantially U-shaped cross section so that the concave portions face each other, and the rear ends of the left and right side side frames 3, 3 ′. The rear frame 4 is connected and fixed to form a hollow box.

An engine section 5 is mounted substantially above the center of the frame 1, that is, above the center of the rear section between the left and right side frames 3, 3 ', and the engine section 5 and the side frames 3, 3'are separated from each other. Engine part 5 and both end frames 3,
Brackets 43, ... Formed integrally with 3 ', respectively, and cushioning mount rubber 4 provided between the brackets 43 ,.
It is connected through 4, ... Further, behind the frame 1, there is a main mission case 6 fitted into the rear frame 4 from the rear side thereof, and the main mission case 6
A mission case 8 including a sub-mission case 7 that is connected to the rear end of the rear frame 4 and is fixed to the rear end of the rear frame 4.
Are arranged, these engine part 5 and mission case 8
Are connected to each other in the rear frame 4 via a connecting shaft 9. A main clutch 6a is housed in the front part of the main mission case 6.

On the other hand, above the rear frame 4, there is arranged a steering handlebar 10 which is inclined at an angle where the driver can easily steer the steering wheel. The upper end of the steering shaft 13 is connected via a universal joint 12. Further, a rear end portion of the steering shaft 13 is connected to a rear end portion of the relay steering shaft 15 via a relay gear case 14 which is disposed in the rear frame 4 and accommodates a bevel gear mechanism therein. The front end portion of is connected to a worm shaft 18 of a steering gear box 17 via a universal joint 16.

The relay gear case 14 is arranged near the left side portion of the rear frame 4 at the front end position in the rear frame 4, and is fixed to a plate 4'provided to cover the front end of the rear frame 4. On the other hand, the steering gear box 17 is disposed in front of the engine unit 5 and in the vicinity of the inner side portion of the left side frame 3,
These relay gear case 14 and steering gear box 17
The relay steering shaft 15 that connects to and is located near the inner side of the left side frame 3 and extends along the extending direction of the left side frame 3. That is, the relay gear case 14, the relay steering shaft 15, and the steering gear box 17 are arranged at substantially the same vehicle height position inside the frame 1. In order to set a so-called play of the steering handle 10 by a predetermined amount, a universal portion is provided at a connecting portion between the steering shaft 13 and the relay gear case 14 or a connecting portion between the relay steering shaft 15 and the relay gear case 14. Joints can be installed.

A pitman arm 20 is attached to the sector shaft 19 of the steering gear box 17, and one end of a first tie rod 21 is attached to the tip of the pitman arm 20 so as to be swingable with respect to the pitman arm 20. The other end of the first tie rod 21 supports the left front wheel 22 arranged on the outer side portion of the left side frame 3 so as to be rotatable and steerable left and right, and a knuckle and reduction case. It is connected to a first knuckle arm 24 formed at the upper part of the front end of 23. Further, a second knuckle arm 25 is formed below the first knuckle arm 24 in the knuckle / reduction case 23, and the second knuckle arm 25 supports the right front wheel 22 '. The knuckle arm 25 'formed at the front end of the combined reduction case 23' is connected to the second tie rod 26.

In the rear frame 4, the mission case 8
The output shaft 30 of the propulsion shaft 31 protrudes obliquely forward from the vicinity of the front of the rear frame 4 to the output shaft 30.
Is connected to the input shaft 33 of the front differential case 32 via. The front differential case 16 includes the steering gear box 17, the pitman arm 20, the first
The left and right axle shafts 34, 34 ′ of the front differential case 32 are disposed substantially inwardly of the center of the frame 1 behind the respective positions of the second tie rods 21, 26. One end of each of them penetrates through the inside of an axle housing 35, 35 ', and further, both axle shafts 34, 34' are
The left and right front wheels 21, 21 'are respectively passed through reduction mechanisms (not shown) housed in the left and right knuckle and reduction cases 23, 23' arranged at the other ends of the axle housings 35, 35 ', respectively. Wheel shaft of 36,36 ′
Are connected to each.

In addition, the axle housings 35 and 35 'and the knuckle and reduction case 23 and 23' are fitted in the knuckle portions (bevel gear case portions) 37 and 37 'formed in the knuckle and reduction cases 23 and 23', respectively. The knuckle and reduction case 23,23 'and the front wheels 21,21' are connected to each other by the kingpins 38,38 '.
It is possible to steer left and right with 38 and 38 'as the center of rotation.

On the other hand, the front diff case 32 has a pair of axle brackets 40, 40 having upper and lower ends 39, the left and right end portions being fixed to the lower end portions of the left and right side frames 3, 3 ', and facing each other in the front-rear direction. As shown in FIG. 1, the upper end portion 39 is swingably supported by an axle pin 41 installed between the upper and lower end portions of the left and right side frames 3, 3'and the vertical direction of the vehicle body. Are overlapped by.

Next, the operation of this embodiment will be described.

When the steering wheel 10 is steered from the neutral position to the left, for example, to the maximum steering angle, the driving force by the steering is transmitted to the steering gear box 17 through the steering wheel shaft 11, the steering shaft 13, the relay gear case 14 and the relay steering shaft 15 in sequence. The steering gear box 17
The pitman arm 20 moves the first tie rod 21 to the left outside of the vehicle body, and the knuckle / reduction case 23 and the front wheel 22 move from the position of arrow A in FIG. Turn counterclockwise to the position,
The front wheel 22 steers fully to the left. Further, the rotation of the knuckle and reduction case 23 causes the second tie rod to be rotated.
25 is moved to the left, and the knuckle / reduction case 23 ′ and the front wheel 22 ′ located on the right side of the vehicle body are rotated counterclockwise around the kingpin 38 ′, like the knuckle / reduction case 23 and the front wheel 22. Turn to the front wheel
22 'runs to the left all the way.

At this time, since the relay steering shaft 15 extends inward of the frame 1, that is, in the vicinity of the inner side of the left side frame 3, it extends substantially along the extending direction of the left side frame 3, The front wheels 22 and 22 'are the relay steering shaft 1
Steer in the desired direction without interfering with 5.

Since the steering gear box 17, the pitman arm 20, and the first and second tie rods 21 and 26 are arranged in front of the front differential case 32 and inside the frame 1, mainly the pitman arm 20 and the 1
It is not necessary to provide a space for driving the tie rods 21 above the front differential case 32, and further, the upper end portion 39 of the front differential case 32 and the lower end edges of the left and right side frames 3, 3'are provided on the vehicle body. It can be overlapped vertically. Therefore, while it is possible to set the vehicle height of the entire vehicle body lower by the amount that the space need not be provided, if the frame has substantially the same height as the conventional one, the front differential case 32 is moved upward due to the overlap. The minimum ground clearance of the lower part of the vehicle body can be set higher than the previous one by the amount of positioning.

Further, since the engine portion 5 is installed above the center of the frame 1 with a cushioning mount rubber 43 ,.
The influence of the vibration of the engine unit 5 on the steering system is reduced.

(Effects of the Invention) As described above, according to the present invention, the relay gear case, the relay steering shaft, and the steering gear box are respectively located inside the frame, and the relay gear case, the relay steering shaft, and the steering gear box are respectively disposed near either one of the left and right sides of the frame. Since the steering wheels are arranged along the front-rear direction of the vehicle body, even if the steering wheel is steered at a large angle, the front wheels do not interfere with the relay steering shaft, so that the maximum steering angle of the steering wheel can be set large.

Moreover, since the relay gear case and the steering gear box are arranged near the left or right frame side portion in the inner position of the frame along the front-rear direction of the vehicle body, respectively, the relay gear case and the steering gear box are connected. Since the relay steering shaft can be configured by one member, the number of parts can be reduced and the manufacturing cost can be reduced.

By arranging the relay gear case at the same vehicle height position as the relay steering shaft and the steering gear box and in a substantially straight line in the front-rear direction, the relay gear case, the relay steering shaft, and the steering gear box are extended in the frame. Since it can be arranged substantially along the existing direction, this frame can be used as a protection member for the relay gear case, the relay steering shaft, and the steering gear box, and the wheel base can be simply changed by changing the length of the relay steering shaft 15. Can be changed easily.

Further, in the case where the main clutch is built in the front part of the transmission case, a space is created between the engine part and the main transmission case, and if this relay gear case is arranged in this space, this space is covered. Not only is the rear frame not expanded laterally of the vehicle body, but also the width of the rear frame can be narrowed, so that the step circumference can be widened, while the steering shaft is arranged in the longitudinal direction of the vehicle body. Since it can be erected substantially vertically toward the part, it is possible to secure a sufficient space around the driver's feet and knees.

[Brief description of drawings]

FIG. 1 is a schematic side view of an embodiment according to the present invention, FIG. 2 is a schematic plan view of FIG. 1, and FIG. 3 is a schematic front view of FIGS. 1 and 2. 1 ... Frame, 5 ... Engine part, 8 ... Mission case (mission system), 10 ... Steering handle, 13 ... Steering shaft, 14 ... Relay gear case, 15 ... Relay steering shaft, 17 ... Steering Gearbox, 22,22 '…… Front wheel.

Claims (3)

[Claims] 1. A steering system that extends in the front-rear direction of a vehicle body, has an engine section mounted substantially above the center thereof, and has a mission system arranged rearward at an inner position of a frame so as to be interlocked with steering of a steering wheel. A relay gear case coupled to the shaft, a relay steering shaft coupled to the relay gear case, a relay steering shaft coupled to the relay steering shaft so that the driving force of the relay gear case can be transmitted, and both outer side portions of the frame. A steering device for a passenger work machine, characterized in that a steering gear box for operably connecting the front wheels arranged therein is disposed in the vicinity of either one of the left and right sides of the frame along the longitudinal direction of the vehicle body. . 2. The riding work according to claim 1, wherein the relay gear case is arranged at substantially the same vehicle height position as the relay steering shaft and the steering gear box and in a substantially straight line in the front-rear direction. Machine steering device. 3. The steering apparatus for a passenger work machine according to claim 1, wherein the relay gear case is arranged in a space portion of a frame formed between the engine portion and the mission system.