JPH07110609B2 - Steering system frame layout - Google Patents

Description

The present invention relates to a structure for arranging a steering system in a frame in a passenger work vehicle or the like, for example.

[Prior art and its problems]

In the conventional structure of the steering system inside the frame of a passenger work vehicle, for example, in the mounting structure of a steering unit in a passenger agricultural machine (No. Shokai 61-5335), a rectangular main frame is used to However, the front differential case (upper end portion) is not configured to face the space portion of the main frame. In addition, the steering drive device for the tractor (No. Shokai 61-175173) is similar to the former in that it uses a rectangular main frame, but it is relayed with the steering gear box installed in the main frame. A relay steering shaft that connects the gear cases is arranged so as to face the lower side portion of the main frame at an oblique angle. Also in this latter steering drive device,
The front differential case (upper end) is not configured to face the inside of the main frame. Therefore, the vehicle height is generally inevitably high in the above-mentioned structure in which both steering systems are arranged in the frame. Moreover, if the relay steering shaft is arranged obliquely from the lower side of the main frame as in the latter case, the main frame Since it is largely exposed to the lower side of the vehicle, there are various inconveniences in the arrangement structure of the steering system of the passenger work vehicle which is apt to be damaged from the outside and performs a predetermined work in a place where the undulation is severe. Further, according to the structure as described above, the strength of the frame is weak, and therefore, there is an inconvenience that the reinforcing member needs to be specially attached.

[Means and Actions for Solving Problems]

The present invention is made in view of the above problems, and at least a steering gear box is provided in front of the front axle.
In a steering system in-frame arrangement structure in which a tie rod, a sector shaft, a pitman arm, and the like are arranged, the steering gear box is arranged in a front space portion of a frame extending in the front-rear direction of the vehicle body and having a rectangular shape as a whole. The upper end of the front differential case is inserted into the rear space of the frame from below, and the oil pan on the bottom of the engine is inserted from above to be arranged in the space of the frame behind the steering gear box and the oil pan. A relay gear case is arranged, and a relay steering shaft connecting the relay gear case and the steering gear box is arranged substantially horizontally along a frame space on the same side as the side on which the steering gear box is arranged.

As a result, the vehicle height of a passenger work vehicle or the like can be made as low as possible and the front view can be widened. Further, the strength of the frame can be strengthened by effectively utilizing the space portion of the rectangular frame. Moreover, since the relay steering shaft disposed between the steering gear box and the relay gear case is guarded by the frame to prevent contact with the outside, damage or the like does not occur.

〔Example〕

The in-frame arrangement structure of the steering system according to the present invention will be described in detail with reference to FIGS. 1, 2, and 3.

In the figure, reference numeral 1 denotes a frame, which extends in the front-rear direction of the vehicle body. The frame 1 includes a front frame 1a to which a bumper (not shown) is attached, and left and right end portions of the front frame 1a. Left and right frames that are connected and fixed to each other and have a U-shaped cross section so that the recesses face each other.
1b and a rear frame 1c connected to the rear ends of the left and right frames 1b.

An engine section 2 is mounted substantially above the center of the frame 1, that is, in the rear center between the left and right frames 1b. The engine unit 2 and the left and right frames 1b are connected via brackets 3 provided on the engine unit 2 and the left and right frames 1b, respectively, and a cushion mount rubber 4 arranged between the brackets 3. The oil pan 2a at the bottom of the engine unit 2 is arranged by being inserted from above into a space behind the left and right frames 1b.
Further, the rear frame 1c is provided behind the frame 1.
The main mission case 5 that is inserted from the rear inside,
A mission case 7 is arranged, which is composed of a sub mission case 6 that is continuously provided at the rear end of the main mission case 5 and is fixedly provided at the rear end of the rear frame 1c. The engine portion 2 and the mission case 7 are connected via a connecting shaft 8 in the rear frame 1c. A main clutch 5a is housed in the front part of the main mission case 5.

On the other hand, above the rear frame 1c, there is arranged a steering handlebar 9 that is inclined at an angle that makes it easy for the driver to steer. At the lower end of the handlebar shaft 10 that forms the rotation shaft of the steering handlebar 9, a universal handle is provided. Joint 11
The upper end of the steering shaft 12 is connected via. A relay gear case 13, which is arranged inside the rear frame 1c and accommodates a bevel gear mechanism, is connected to the lower end of the steering shaft 12. A rear end portion of the relay steering shaft 14 is connected to the relay gear case 13, and a front end portion of the relay steering shaft 14 is connected to a worm shaft 17 of a steering gear box 16 via a universal joint 15.

The relay gear case 13 is arranged near the left side of the rear frame 1c at the front end position in the rear frame 1c, and is fixed to a plate 1d provided so as to cover the front end of the rear frame 1c. . The relay steering shaft 14 that connects the relay gear case 13 and the steering gear box 16 is located in the vicinity of the side portion of the left side frame 1b inside the left and right frames 1b and extends substantially horizontally along the left side frame 1b. It is set up. That is, the relay gear case 13
And relay steering shaft 14 and steering gear box 16
Are arranged at substantially the same vehicle height position inside the frame 1. The steering shaft is set so that the so-called play of the steering handle 9 can be set by a predetermined amount.
A universal joint can be provided at the connecting portion between 12 and the relay gear case 13 and at the connecting portion between the relay steering shaft 14 and the relay gear case 13.

Further, a sector shaft 18 is vertically hung in the steering gear box 16, and a pitman arm 19 is attached to the sector shaft 18. One end of a first tie rod 20 is swingably attached to the tip of the pitman arm 19, and the other end of the first tie rod 20 is located outside the left and right frames 1b. Is connected to a first knuckle arm 23 formed at the upper front end of a knuckle / reduction case 22 that supports the left front wheel 21 rotatably and steerably left and right. A second knuckle arm 24 is provided below the first knuckle arm 23 of the knuckle / reduction case 22. The second knuckle arm 24 is the right front wheel 21.
The knuckle arm 24 provided at the front end of the knuckle / reduction case 22 that supports the knuckle is connected to the tie rod 25.

The output shaft 26 of the mission case 7 projects into the rear frame 1c.
It is connected to an input shaft 29 of a front differential case 28 via a propulsion shaft 27 extending obliquely forward from the vicinity of the front of 1c.
Further, the front differential case 28 includes the frame 1 behind the steering gear box 16, the pitman arm 19, and the first and second tie rods 20 and 25, respectively.
It is located approximately in the center of the inside. The left and right axle shafts 30 of this front differential case 28 are the front differential case.
One end of each of the left and right sides of 28 penetrates through an axle housing 31 that is integrally mounted. Left and right knuckle / reduction cases 22 are arranged at the other ends of the axle housings 31, respectively. The left and right axle shafts 30 are connected to the left and right front wheels 21 through the reduction mechanisms housed in the left and right knuckle and reduction cases 22, respectively.
Are connected to the respective wheel shafts 32 of.

The axle housing 31 and the knuckle / reduction case 22 are connected by a king pin 34 mounted in a knuckle portion (bevel gear case portion) 33 formed in the knuckle / reduction case 22, respectively. As a result, the knuckle / reduction case 22 and the front wheel 21 can be steered left and right with the kingpin 34 as the center of rotation of each.

On the other hand, the upper end portion 35 of the front differential case 28 is the left and right frames.
Both left and right end portions are fixed to the lower end portion of 1b, and are swingably supported by an axle pin 37 provided between a pair of axle brackets 36 facing each other in the front-rear direction. As shown in FIG. 1, the upper end portion 35 overlaps the lower end edges of the left and right frames 1b in the vertical direction of the vehicle body.

Next, the operation of this embodiment will be described.

Since the relay steering shaft 14 is located inward of the frame 1, that is, in the vicinity of the inner portion of the left frame 1b, and extends substantially horizontally along the extending direction of the left frame 1b,
The front wheels 21 are steered in a desired direction without interfering with the relay steering shaft 14.

Further, since the steering gear box 16, the pitman arm 19, and the first and second tie rods 20 and 25 are arranged in front of the front differential case 28 and inside the frame 1, the pitman arm 19 and the first tie rod are mainly arranged. A space for driving the tie rod 20 of the front differential case
It does not need to be provided above 28. Further, the upper end portion 35 of the front differential case 28 is inserted into the space portion of the frame 1 from below the frame 1, and the oil pan 2a of the engine portion 2 is inserted.
Are arranged by being inserted into the space of the frame 1 from above the frame 1, so that the upper end portion 35 of the front diff case 28 and the oil pan 2a of the engine portion 2 are vertically overlapped with each other at the lower end portions of the left and right frames 1b. It can be wrapped and the space in the frame 1 can be effectively used. The vehicle height of the entire vehicle body can be set lower by the amount of effective use, and the structure can be robust in terms of strength.
On the other hand, the minimum ground clearance at the lower part of the vehicle body can be set higher than the conventional one by the amount that the front differential case 28 is positioned above by the overlap as described above.

Further, since the engine unit 2 is installed above the center of the frame 1 via the cushioning mount rubber 4, the influence of the vibration of the engine unit 2 on the steering system is mitigated.

〔The invention's effect〕

As described in detail above, the present invention has a structure in which a steering gear box, a tie rod, a sector shaft, a pitman arm, and the like are arranged in front of the front axle in a frame of a steering system. The steering gear box is arranged in the front space of the frame formed in a rectangular shape, and the upper end of the front differential case is inserted from below in the rear space of this frame, and the oil pan at the bottom of the engine is inserted from above. And a relay gear case is disposed in a space portion of the frame behind the steering gear box and the oil pan, and a relay steering shaft connecting the relay gear case and the steering gear box is disposed with the steering gear box. Along with the frame space on the same side Because disposed in a substantially horizontal Te may widen the front sight and as low as possible in vehicle height in passenger work vehicle and the like. Moreover, the strength of the frame can be strengthened by effectively utilizing the space portion of the rectangular frame. Moreover, since the relay steering shaft arranged between the steering gear box and the relay gear box can be guarded by the frame, no inconvenience due to contact with the outside occurs.

[Brief description of drawings]

1 to 3 show an embodiment of a structure for disposing a steering system in a frame according to the present invention. FIG. 1 is a schematic side view of the whole, and FIG. 2 is a plan view showing a main part thereof. FIG. 3 is likewise a vertical cross-sectional view showing the main part. 1 ... frame, 1a ... front frame, 1b ... left and right frame, 1c ... rear frame, 2 ... engine part, 3 ...
Bracket, 4 ... Mount rubber, 2a ... Oil pan,
5 ... Main mission case, 6 ... Sub mission case, 7 ... Mission case, 8 ... Connecting shaft, 5a ... Main clutch, 9 ... Steering handle, 10 ... Steering wheel shaft, 11 ... Universal joint, 12 ... Steering shaft, 13 ... Relay gear case, 14 ... Relay steering shaft, 15 ... Universal joint, 16 ... Steering gear box, 17 ... Worm shaft, 18 ... Sector shaft, 19 ... Pitman arm, 20 …… First tie rod, 21 …… Front wheel, 22 …… Knuckle and reduction case, 23 …… First knuckle arm, 24 …… Second knuckle arm, 25 …… Second tie rod, 26 …… Output shaft, 27
…… Propulsion shaft, 28 …… Front differential case, 29 …… Input shaft, 30 …… Axle shaft, 31 …… Axle housing, 32 …… Wheel shaft, 33 …… Knuckle part (bevel gear case part), 34 …… King pin , 35 …… Upper end, 36
…… Axle bracket, 37 …… Axle pin.

Claims (1)

[Claims] 1. A steering system in-frame arrangement structure in which at least a steering gear box, a tie rod, a sector shaft, a pitman arm, and the like are arranged in front of a front axle, and is extended in the front-rear direction of a vehicle body to be entirely rectangular. The steering gear box is arranged in the front space of the frame, the upper end of the front differential case is inserted into the rear space of the frame from below, and the oil pan at the bottom of the engine is inserted from above to dispose the steering gear box. A relay gear case is arranged in the space of the frame behind the gear box and the oil pan, and the relay steering shaft connecting the relay gear case and the steering gear box is on the same side as the side on which the steering gear box is arranged. It is arranged almost horizontally along the space. Frame arrangement of a steering system characterized by.