Work vehicle

Patent metadata

Field	Value
Publication number	US-11458790-B2
Application number	US-202017111242-A
Country	US
Kind code	B2
Filing date	Dec 3, 2020
Priority date	Jun 25, 2020
Publication date	Oct 4, 2022
Grant date	Oct 4, 2022

Abstract

Provided is a work vehicle including a wheel support member including an axle that supports a pair of left and right travel wheels; a link mechanism that is provided spanning between a vehicle body and the wheel support member, and that supports the wheel support member such that the wheel support member can be raised and lowered; and a suspension mechanism that is provided spanning between a suspension support section formed on the vehicle body and the wheel support member, and that elastically supports the wheel support member.

First claim

What is claimed is:

1. A work vehicle comprising:
a wheel support member including an axle that supports a pair of left and right travel wheels
a link mechanism that is provided spanning between a vehicle body and the wheel support member, and that supports the wheel support member such that the wheel support member can be raised and lowered; and
a suspension mechanism that is provided spanning between a suspension support section formed on the vehicle body and the wheel support member, and that elastically supports the wheel support member,
wherein a lower end of the suspension mechanism is arranged substantially directly above the axle, and
Expression (1) is satisfied:
Sin(θ+α)·cos θ>0  (1)

wherein 0 is an angle formed by the suspension mechanism and a vertical line, and a is an angle formed by a straight line passing through a supporting location of the suspension mechanism for the wheel support member and the axle and a vertical line.

2. The work vehicle according to claim 1 , wherein one end of the suspension mechanism is supported by the suspension support section so as to be swingable about a first axis, and another end of the suspension mechanism is supported by the wheel support section so as to be swingable about a second axis.

3. The work vehicle according to claim 1 , wherein the suspension mechanism includes a suspension spring, and a damper that is passed through the suspension spring, and
wherein one end of the damper is supported by the suspension support section so as to be swingable about a first lateral axis, and another end of the damper is supported by the wheel support section so as to be swingable about a second lateral axis.

4. The work vehicle according to claim 3 , wherein Expression (4) below is satisfied:
α=tan−1{( Ws 2·tan θ2− Ws 1·tan θ1)/( Ws 1− Ws 2)}  (4)

wherein Ws1 is a reaction force of the suspension spring under a first loading condition, θ1 is a value of θ under the first loading condition, Ws2 is a reaction force of the suspension spring under a second loading condition in which a load weight is larger than the first loading condition, and θ2 is a value of θ under the second loading condition.

5. The work vehicle according to claim 4 , wherein Expression (5) below is satisfied:
L=lw·Wu/Ws 1×( Ws 1− Ws 2)/{ Ws 2·tan θ2− Ws 1·tan θ1+( Ws 1 −Ws 2)·sin α}   (5)

wherein L is a distance between the first axis and the axis of the axle, lw is a horizontal distance between the axis of the axle and a center of gravity of a spring lower portion that is a portion suspended from the suspension mechanism, and Wu is the weight of the spring lower portion.

6. The work vehicle according to claim 1 , wherein the link mechanism includes:
an upper link having a front end portion supported so as to be swingable up and down about an upper pivotal support axis by a link support section formed on the vehicle body, and a rear end portion coupled to the wheel support member so as to be swingable about an upper coupling axis relative to the wheel support member; and
a lower link having a front end portion supported by the link support section so as to be swingable up and down about a lower pivotal support axis, and a rear end portion coupled to the wheel support member so as to be swingable about a lower coupling axis relative to the wheel support member.

7. The work vehicle according to claim 1 , wherein an upper link is supported by the link support section via a first elastic member, and
wherein a lower link is supported by the link support section via a second elastic member.

8. The work vehicle according to claim 1 , wherein an upper link is supported by the wheel support member via a first elastic member, and
wherein a lower link is supported by the wheel support member via a second elastic member.

Assignees

• Kubota Kk

Inventors

• Azuma Masahiro

Classifications

• B60G11/58

  arranged coaxially · CPC title

• B60G2204/148

  on the unsprung part of the vehicle, e.g. wheel knuckle or rigid axle · CPC title

• B60G2300/124

  Quads · CPC title

• B60G2204/143

  on the vehicle body or chassis · CPC title

• B60G2200/13

  with longitudinal arms only · CPC title