Patent Description:
In the related art, in a work vehicle, a method is known in which an engine is mounted on a hood portion, and an output rotation of the engine is transmitted to rear wheels or a work machine such as a mower deck supported by a lower portion of the work vehicle so as to be movable up and down, thereby driving the work vehicle (see <CIT>).

In addition, in a work vehicle, a method is known in which a battery is mounted on a rear portion of the work vehicle, electric power of the battery is supplied to an electric motor, and an output rotation of the electric motor is transmitted to rear wheels or a work machine such as a mower deck supported by a front portion of the work vehicle so as to be movable up and down, thereby driving the work vehicle (see <CIT>).

However, in the method in <CIT>, since the configuration of a transmission device that transmits the output rotation of the engine to the rear wheels or the work machine is complicated and the number of components is large, a weight of the work vehicle may be heavy.

Further, in the method in <CIT>, since the battery is mounted on the rear portion of the work vehicle, a weight balance in a front-rear direction of the work vehicle may be deteriorated, and maneuverability may be deteriorated.

<CIT> shows a generic work vehicle according to the preamble of claim <NUM>, comprising: a pair of left and right front wheels provided at a front portion of a traveling vehicle body; a pair of left and right rear wheels provided at a rear portion of the traveling vehicle body; and a work machine provided on a lower surface of the traveling vehicle body, wherein a hood is provided at the front portion of the traveling vehicle body, and a control portion on which an operator rides is provided at a rear side of the hood, a first electric motor configured to drive the rear wheels and a second electric motor configured to drive the work machine are provided on a lower rear side of a control seat of the control portion, a battery configured to store electric power supplied to the first electric motor and the second electric motor is provided in a space formed by the hood, and a first output shaft of the first electric motor is provided along a left-right direction, and a second output shaft of the second electric motor is provided along a front-rear direction.

A further work vehicle according to prior art is shown in <CIT>.

It is the object of the invention to further develop a work vehicle according to the preamble of claim <NUM> such that a space formed below a first electric motor can be effectively utilized.

The object of the invention is achieved by a work vehicle having the features of claim <NUM>.

Further advantageous developments according to the invention are defined in the dependent claims.

It is an advantage of the invention to provide a work vehicle in which a weight of the work vehicle is reduced, and a weight balance in a front-rear direction of the work vehicle is improved, thereby improving maneuverability.

According to the invention, a hood in which a predetermined space is formed is provided on a front side of an upper surface of a traveling vehicle body, a control portion on which an operator rides is provided on a rear side of the hood, a first electric motor configured to drive rear wheels and a second electric motor configured to drive a work machine are provided on a lower rear side of a control seat of the control portion, and a battery configured to store electric power to be supplied to the first electric motor and the second electric motor is provided on the hood. Therefore, a weight balance of the traveling vehicle body can be improved. The space formed in the hood can be effectively utilized. Further, the first output shaft of the first electric motor is provided along the left-right direction, and the second output shaft of the second electric motor is provided along the front-rear direction. The number of components of a transmission mechanism between the first electric motor and the rear wheels and a transmission mechanism of the second electric motor and the work machine can be reduced to further reduce a load applied to the traveling vehicle body. Here, the gear box for decelerating the output rotation of the first output shaft and switching a rotation direction is provided on one side of the first electric motor, the rear wheels and the gear box are coupled by the drive shaft extending in the left-right direction, the first electric motor is provided above the second electric motor, and the second output shaft is provided above the drive shaft. Therefore, a space formed below the first electric motor can be effectively utilized.

Preferably, the second electric motor is provided below the first electric motor, and the second output shaft is provided above the drive shaft so as to intersect with the drive shaft in the plan view. Therefore, a space formed below the first electric motor can be more effectively utilized.

Preferably, the first electric motor and the second electric motor are provided to be shifted to one side in the left-right direction, and the chute is provided on the other side of the first electric motor) and the second electric motor. Therefore, a large chute can be provided on an opposite side of the first electric motor and the second electric motor.

As shown in <FIG>, a work vehicle such as a riding lawn mower includes a traveling vehicle body <NUM>, a pair of left and right front wheels <NUM> provided at a front portion of the traveling vehicle body <NUM>, a pair of left and right rear wheels <NUM> provided at a rear portion of the traveling vehicle body <NUM>, and a work machine <NUM> for mowing lawn or the like provided between the front wheels <NUM> and the rear wheels <NUM> on a lower side of the traveling vehicle body <NUM>. Further, a hood <NUM> is provided at a front portion of an upper side of the traveling vehicle body <NUM>, a control portion <NUM> on which an operator rides is provided at a rear side of the hood <NUM>, a safety frame (ROPS) <NUM> for protecting the operator is provided at a rear side of the control portion <NUM>, and a grass collection container <NUM> for storing lawn or the like mowed by the work machine <NUM> is provided at a lower portion of the safety frame <NUM>.

As shown in <FIG> and <FIG>, the hood <NUM> is provided with a battery <NUM> for storing electric power to be supplied to a first electric motor <NUM> and the like for driving the rear wheels <NUM>, and the battery <NUM> is covered with a hood cover <NUM>. The hood cover <NUM> is supported by a support shaft (not shown) provided at a front portion of the traveling vehicle body <NUM> and extending in a left-right direction. Accordingly, a space formed in the hood <NUM> can be effectively utilized, and a difference in a weight balance in a front-rear direction of the work vehicle can be prevented.

An electrical component <NUM> is provided on a lower side of a control seat <NUM> of the control portion <NUM>. Accordingly, a space formed on the lower side of the control seat <NUM> can be effectively utilized.

The safety frame <NUM> includes a left pillar portion <NUM> extending in an up-down direction, a right pillar portion 8R extending in the up-down direction, and an inverted U-shaped coupling portion 8A coupling upper portions of the left pillar portion <NUM> and the right pillar portion 8R.

As shown in <FIG>, the first electric motor <NUM> such as a synchronous electric motor or an induction electric motor operated by a three-phase AC voltage waveform for driving the rear wheels <NUM> is provided below the electrical component <NUM>. A first output shaft 30A formed to extend in the left-right direction of the first electric motor <NUM> is coupled to an upper portion of a gear box <NUM> that decelerates an output rotation transmitted from the first output shaft 30A to increase an output torque or reverse a rotation direction. The first electric motor <NUM> is provided at a position shifted to a left side from a center in the left-right direction.

The output rotation accelerated or decelerated by the gear box <NUM> is transmitted to a drive shaft <NUM> extending in the left-right direction via a differential gear <NUM> provided in a lower portion of the gear box <NUM> and formed by a differential gear or the like. The output rotation transmitted to the drive shaft <NUM> is transmitted to the rear wheels <NUM> supported by both end portions of the drive shaft <NUM>.

A second electric motor <NUM> such as a synchronous electric motor or an induction electric motor operated by a three-phase AC voltage waveform for driving the work machine <NUM> is provided below the first electric motor <NUM>. A second output shaft 40A formed to extend in the front-rear direction of the second electric motor <NUM> is coupled to a rear portion of a universal joint <NUM> provided to extend in the front-rear direction. The second output shaft 40A is provided above the drive shaft <NUM> so as to be orthogonal to the drive shaft <NUM>. Accordingly, a space formed below the first electric motor <NUM> can be effectively utilized. Since a transmission path between the second electric motor <NUM> and the work machine <NUM> can be shortened, the output rotation of the second electric motor <NUM> can be efficiently transmitted to the work machine <NUM>. The second electric motor <NUM> is provided at a position shifted to the left side from the center in the left-right direction.

A front portion of the universal joint <NUM> is coupled to a gear box <NUM> that decelerates an output rotation transmitted from the universal joint <NUM> to increase an output torque. The output rotation transmitted to the gear box <NUM> is transmitted to a left cutting blade (not shown) provided in a left discharge passage <NUM> of the work machine <NUM> via an output shaft formed to extend in the up-down direction of the gear box <NUM>.

A coupling member <NUM> extending in the left-right direction is coupled to a right portion of the gear box <NUM>, and a right portion of the coupling member <NUM> is coupled to a gear box <NUM>. The output rotation transmitted to the gear box <NUM> is transmitted to a right cutting blade (not shown) provided in a right discharge passage 45R of the work machine <NUM> via an output shaft formed to extend in the up-down direction of the gear box <NUM>. A rotation speed of the output rotation of the output shaft of the gear box <NUM> and a rotation speed of the output rotation of the output shaft of the gear box <NUM> are the same, and rotation directions are opposite to each other, that is, in a plan view, the output shaft of the gear box <NUM> rotates in a clockwise direction, and the output shaft of the gear box <NUM> rotates in a counterclockwise direction.

Outlet ports of the left discharge passage <NUM> and the right discharge passage 45R are coupled to an inlet port of a chute <NUM> for conveying cut lawn or the like to the grass collection container <NUM>. An outlet port of the chute <NUM> is coupled to an inlet port of the grass collection container <NUM>.

In the plan view, a front portion of the chute <NUM> is provided on a right side of the universal joint <NUM>, a rear portion of the chute <NUM> is provided on a right side of the gear box <NUM>. In a rear view, the chute <NUM> and the grass collection container <NUM> are provided between the gear box <NUM> and the right rear wheel <NUM>. Accordingly, the large chute <NUM> can be provided in a space formed on the right side of the universal joint <NUM> and the gear box <NUM>, and the lawn or the like mowed by the work machine <NUM> can be efficiently conveyed to the grass collection container <NUM>.

In a side view, an upper wall of the chute <NUM> is formed to be inclined rearward and upward, and the rear portion of the chute <NUM> is provided to extend downward on a lower side of the electrical component <NUM>. Accordingly, the rear portion of the chute <NUM> can be enlarged to prevent the inside of the chute <NUM> from being clogged with lawn or the like.

As shown in <FIG> and <FIG>, the traveling vehicle body <NUM> includes a traveling vehicle body main body <NUM> that supports the front wheels <NUM> and the rear wheels <NUM>, and a steering post <NUM> that supports a steering shaft <NUM>.

A left front and rear frame <NUM> and a right front and rear frame 10R extending in the front-rear direction are formed in the traveling vehicle body main body <NUM>, and a left coupling portion <NUM> and a right coupling portion 11R extending forward are formed in a lower portion of the steering post <NUM>.

The left coupling portion <NUM> is fixed to the left front and rear frame <NUM> by a fastening member such as bolts, and the right coupling portion 11R is fixed to the right front and rear frame 10R by a fastening member such as bolts, so that the traveling vehicle body main body <NUM> and the steering post <NUM> are integrated to form the traveling vehicle body <NUM>.

A left support member <NUM> is provided at a front portion of the left front and rear frame <NUM>, and a coupling portion of the left support member <NUM> is formed to be inclined upward to the left. A right support member 12R is provided at a front portion of the right front and rear frame 10R, and a coupling portion of the right support member 12R is formed to be inclined upward to the right. The left support member <NUM> and the right support member 12R are formed of a channel steel material.

A left support member <NUM> is provided at a front portion of the left coupling portion <NUM>, and a coupling portion of the left support member <NUM> is formed to be inclined upward to the left. A right support member 13R is provided at a front portion of the right coupling portion 11R, and a coupling portion of the right support member 12R is formed to be inclined upward to the right. The left support member <NUM> and the right support member 13R are formed of a channel steel material.

Protruding portions <NUM> are formed at a lower portion of the steering post <NUM> so as to protrude to the front side at a predetermined interval in the left-right direction. A buffer member <NUM> formed of a rubber member or the like is provided at a tip end of each of the protruding portions <NUM>.

A left up and down frame <NUM> extending upward is provided at a rear portion of the left front and rear frame <NUM>, a right up and down frame 20R extending upward is provided at a rear portion of the right front and rear frame 10R. Upper portions of the left up and down frame <NUM> and the right up and down frame 20R are coupled to a left and right frame <NUM> extending in the left-right direction.

A left coupling portion <NUM> to which a lower portion of the left pillar portion <NUM> of the safety frame <NUM> is coupled is provided at a left portion of the left and right frames <NUM>. A right coupling portion 22R to which a lower portion of the right pillar portion 8R of the safety frame <NUM> is coupled is provided at a right portion of the left and right frame <NUM>.

As shown in <FIG>, a lower portion of the battery <NUM> provided in the hood <NUM> is fitted into an inner peripheral portion of a battery bracket <NUM>. The battery <NUM> is formed by connecting a plurality of lithium ion batteries having a high energy density in series and in parallel. Accordingly, a space formed in the hood <NUM> can be utilized. Further, since the lithium ion battery has a high energy density, the work vehicle can travel for a long distance by one full charge.

As shown in <FIG>, the battery bracket <NUM> includes a left front and rear frame <NUM> and a right front and rear frame 52R extending in the front-rear direction, a front left and right frame 52A coupling front portions of the left front and rear frame <NUM> and the right front and rear frame 52R, and a rear left and right frame 52B coupling rear portions of the left front and rear frame <NUM> and the right front and rear frame 52R. The left front and rear frame <NUM> and the right front and rear frame 52R are formed of an angle steel material. The front left and right frame 52A and the rear left and right frame 52B are formed of a channel steel material.

A coupling portion of the left front and rear frame <NUM> is formed to be inclined upward to the left. A coupling portion of the right front and rear frame 52R is formed to be inclined upward to the right. In the rear view, the coupling portion of the left support member <NUM>, the coupling portion of the left support member <NUM>, and the coupling portion of the left front and rear frame <NUM> are inclined upward to the left at the same inclination angle. The coupling portion of the right support member 13R, the coupling portion of the right support member 12R, and the coupling portion of the right front and rear frame 52R are inclined upward to the right at the same inclination angle.

Circular left vibration isolating members <NUM> are provided on a lower surface of the coupling portion of the left front and rear frame <NUM> at a predetermined interval in the front-rear direction. Circular right vibration isolating members 53R are provided on a lower surface of the coupling portion of the right front and rear frame 52R at a predetermined interval in the front-rear direction.

The left front and rear frame <NUM> is coupled to the left support member <NUM> of the left front and rear frame <NUM> and the left support member <NUM> of the left coupling portion <NUM> via the left vibration isolating members <NUM>. The right front and rear frame 52R is coupled to the right support member 12R of the right front and rear frame 10R and the right support member 13R of the right coupling portion 11R via the right vibration isolating members 53R. Accordingly, it is possible to prevent the vibration of the traveling vehicle body main body <NUM> generated during traveling of the work vehicle from being transmitted to the battery <NUM>, and it is possible to prevent damage or the like on the battery <NUM>.

As shown in <FIG>, the coupling portion of the left front and rear frame <NUM> is provided perpendicular to a left imaginary line <NUM> connecting a center of the left vibration isolating member <NUM> and a center of the left front wheel <NUM>. The coupling portion of the right front and rear frame 52R is provided perpendicular to a right imaginary line 55R connecting a center of the right vibration isolating member 53R and a center of the right front wheel 2R. Accordingly, it is possible to prevent large vibration caused by unevenness of a traveling surface via the front wheels <NUM> and the rear wheels <NUM>, and to prevent damage or the like on the battery <NUM>. A reference numeral <NUM> denotes a front wheel support frame that supports the left and right front wheels <NUM>. A reference numeral <NUM> denotes a coupling portion between the front wheel support frame and the traveling vehicle body main body <NUM>, and denotes a swing shaft of the front wheel support frame.

Tip end portions of the buffer members <NUM> of the steering post <NUM> are pressed against a rear surface of the rear left and right frames 52B of the battery bracket <NUM>. Accordingly, it is possible to prevent a rearward movement of the battery <NUM> at the time of starting the work vehicle, and to prevent damage or the like on the battery <NUM>.

As shown in <FIG>, a battery charger <NUM> for the battery <NUM> and a storage case <NUM> for storing a charging cable <NUM> are provided on a front side of the battery <NUM>. Accordingly, when a charge amount of the battery <NUM> is equal to or less than a predetermined value, the work vehicle can be moved to a nearby warehouse or the like without being moved to a charging station, and the battery <NUM> can be charged by connecting a household outlet provided in a warehouse or the like and the charger <NUM> by the charging cable <NUM>. An input voltage of the charger <NUM> is formed so as to correspond to an AC voltage of <NUM> to <NUM> V.

As shown in <FIG>, the charger <NUM> is provided at a lower portion of a front surface of a rectangular support member <NUM> detachably provided to the front left and right frame 52A of the battery bracket <NUM> by a fastening member such as bolts. The storage case <NUM> is provided at an upper portion of the front surface of the support member <NUM>. Accordingly, after the hood cover <NUM> is opened, the charging cable <NUM> having one end connected to the household outlet can be inserted from a lower side to an upper side in a space defined by the traveling vehicle body main body <NUM> and the charger <NUM>, and the other end of the charging cable <NUM> can be connected to the charger <NUM>. Therefore, a charging operation can be performed without moving the work vehicle to the vicinity of the household outlet.

A fan 75A is formed on a left front portion of the charger <NUM>, and a plurality of fins 75B are formed on an outer peripheral portion of the charger <NUM>. Accordingly, heat generated during charging of the charger <NUM> can be efficiently released to an outside, and temperature rise of the charger <NUM> during the charging can be reduced.

As shown in <FIG> and <FIG>, a rear surface of the charger <NUM> is mounted on the support member <NUM> via extending portions 77A formed in a lower portion of the front surface of the support member <NUM> and extending forward. Accordingly, a space is formed between the charger <NUM> and the support member <NUM>, the heat generated during the charging of the charger <NUM> can be more efficiently released to the outside, and the temperature rise of the charger <NUM> during the charging can be further reduced. The support member <NUM> is preferably formed of a member in which a plurality of openings are formed, such as punching metal.

As shown in <FIG>, a plug 78A to be connected to the household outlet is formed at one end of the charging cable <NUM>, and a plug 78B to be connected to a connection terminal of the charger <NUM> is formed at the other end of the charging cable <NUM>.

As shown in <FIG>, instead of the storage case <NUM> for storing the charging cable <NUM>, a hook <NUM> for locking the charging cable <NUM> may be provided on an upper portion of the support member <NUM>. Accordingly, a large opening 77B is formed between the hook <NUM> and the charger <NUM> in the support member <NUM>, air is blown toward the front portion of the battery <NUM>, and the temperature rise of the battery <NUM> during the charging and discharging can be reduced. The rear surface of the charger <NUM> is mounted on the support member <NUM> via the extending portions 77A which are formed at left and right ends of the support member <NUM> and extend forward, and a large space is formed on an upper side of the charger <NUM>. When the hood cover <NUM> is opened, external air is efficiently blown toward the charger <NUM>, and the temperature rise of the charger <NUM> during the charging can be further reduced.

The hook <NUM> includes a left round bar portion <NUM> that extends forward from the front surface of the support member <NUM> and then extends upward, a right round bar portion 79R that extends forward from the front surface of the support member <NUM> and then extends upward, and a left and right round bar portion 79A that couples upper portions of the left round bar portion <NUM> and the right round bar portion 79R and extends in the left-right direction.

As shown in <FIG> and <FIG>, a protection frame <NUM> extending along an outer peripheral portion of the battery <NUM> is provided at an intermediate portion of the battery <NUM> in the front-rear direction. Accordingly, it is possible to prevent the battery <NUM> from being damaged when the work vehicle falls down.

The protection frame <NUM> includes a left pillar portion <NUM> extending upward from the left front and rear frame <NUM>, a right pillar portion 58R extending upward from the right front and rear frame 10R, and an inverted U-shaped coupling portion ("second coupling portion") 58A coupling upper portions of the left pillar portion <NUM> and the right pillar portion 58R.

In the side view, an imaginary line ("third imaginary line") <NUM> coupling a base portion of the coupling portion 58A of the protection frame <NUM> and a top portion of the coupling portion ("first coupling portion") 8A of the safety frame <NUM> is formed so as to be positioned above a steering wheel <NUM>. Accordingly, a large protection space is formed below the imaginary line <NUM>, and it is possible to prevent the operator from colliding with a branch or the like of an external tree when the work vehicle is traveling, thereby improving work safety.

As shown in <FIG> and <FIG>, the steering wheel <NUM> is provided on a front side of the control seat <NUM> of the control portion <NUM>, and the steering wheel <NUM> is supported by an upper portion of the steering shaft <NUM> extending in the up-down direction.

A left fender <NUM> on a left side of the control seat <NUM> is provided with a cleaner lever <NUM> for operating, for example, conveying mowed grass remaining in the chute <NUM> to the grass collection container <NUM> on the rear side. A right fender 64R on a right side of the control seat <NUM> is provided with an operation lever <NUM> for operating an up and down movement of the work machine <NUM>. Further, a brake pedal <NUM> is provided at a left front portion of a floor <NUM> on which an operator places his/her feet at the time of steering, and a forward accelerator pedal <NUM> and a reverse accelerator pedal <NUM> are provided side by side at a right front portion of the floor <NUM>.

As shown in <FIG>, the electrical component <NUM> provided in a space formed between the chute <NUM> of the work machine <NUM> and the control seat <NUM> includes an inverter device <NUM> that converts a DC voltage supplied from the battery <NUM> into an AC voltage to generate a three-phase AC voltage waveform for operating the first electric motor <NUM> and the like, a battery monitoring device <NUM> that monitors a temperature, a charging state, a voltage protection, and each cell short circuit state of the battery <NUM>, an auxiliary battery <NUM> such as a lead storage battery that stores a battery to be supplied to a meter panel (not shown) that is provided on a front side of the control seat <NUM> and displays a traveling speed and the like, and a converter device <NUM> that changes the DC voltage supplied from the battery <NUM> to a DC voltage to be supplied to a sensor that detects an operation position of the cleaner lever <NUM> and the like.

Provided is a work vehicle in which deterioration in a weight balance of the work vehicle in a front-rear direction is prevented and maneuverability is improved.

Claim 1:
A work vehicle comprising:
a pair of left and right front wheels (<NUM>) provided at a front portion of a traveling vehicle body (<NUM>);
a pair of left and right rear wheels (<NUM>) provided at a rear portion of the traveling vehicle body (<NUM>); and
a work machine (<NUM>) provided on a lower surface of the traveling vehicle body (<NUM>), wherein
a hood (<NUM>) is provided at the front portion of the traveling vehicle body (<NUM>), and a control portion (<NUM>) on which an operator rides is provided at a rear side of the hood (<NUM>),
a first electric motor (<NUM>) configured to drive the rear wheels (<NUM>) and a second electric motor (<NUM>) configured to drive the work machine (<NUM>) are provided on a lower rear side of a control seat (<NUM>) of the control portion (<NUM>),
a battery (<NUM>) configured to store electric power supplied to the first electric motor (<NUM>) and the second electric motor (<NUM>) is provided in a space formed by the hood (<NUM>), and
a first output shaft (30A) of the first electric motor (<NUM>) is provided along a left-right direction, and a second output shaft (40A) of the second electric motor (<NUM>) is provided along a front-rear direction,
characterized in that
a gear box (<NUM>) configured to transmit an output rotation of the first output shaft (30A) to a lower drive shaft (<NUM>) is provided on one side of the first electric motor (<NUM>),
the rear wheels (<NUM>) and the gear box (<NUM>) are coupled by the lower drive shaft (<NUM>), and the second electric motor (<NUM>) is provided below the first electric motor (<NUM>), and
the second output shaft (40A) is provided above the lower drive shaft (<NUM>).