Patent Description:
A work vehicle such as an agricultural tractor having a front ROPS member is known (see, for example, <CIT>).

In <CIT> there is mention of a front attachment plate fixed to a (trans) -mission case of a tractor with bolts. This document is considered closest prior art.

Document <CIT> (D2) also mentions mounting of a support frame at a transmission casing is mentioned. The support frame shall be easily demountable and serves to support a cabin consisting of easy-to-fit panels. When these panels are not mounted, the frame serves as protection for the driver i.e. as a ROPS member.

In the document, two alternatives for mounting at the sides or below the transmission case are shown.

According to <CIT>, a ROPS unit is arranged at (a rear side of) a transmission case. The problem described here is that the arrangement restricts working capabilities at a driving unit.

As a solution, according to this teaching, a ROPS frame is disposed at a front portion of the driving unit. The ROPS frame is mounted at the transmission case.

Document <CIT> discloses another generic work vehicle.

However, in the work vehicle such as the agricultural tractor in the related art as described above, attachment of the ROPS member is not always sufficiently firm.

The object of the invention is to provide a work vehicle on which a ROPS member can be more firmly attached in consideration of the above-described problem in the related art.

The object of the invention is achieved by a work vehicle according to claim <NUM>. Advantageous embodiments are carried out according to the dependent claims.

According to the invention, a work vehicle includes: a front frame configured to support a front wheel; a transmission mechanism configured to transmit power; and a front ROPS member, the front ROPS member is fixed to a front ROPS left plate and a front ROPS right plate, and each of the front ROPS left plate and the front ROPS right plate is attached to the front frame and the transmission mechanism.

Accordingly, a simple attachment configuration of the ROPS member can be implemented.

According to the invention, a left spacer plate can be inserted between a front portion of the front ROPS left plate and the front frame, and a right spacer plate can be inserted between a front portion of the front ROPS right plate and the front frame.

Accordingly, since the left spacer plate is inserted and the right spacer plate is inserted, a flexible configuration can be implemented.

According to the invention, in the front ROPS member, a front ROPS left pillar member and a front ROPS right pillar member can be obtained by dividing a U-shaped pipe member in the vicinity of a center of the U shape.

Therefore, the front ROPS left pillar member and the front ROPS right pillar member are obtained by dividing the U-shaped pipe member in the vicinity of the center of the U shape, and thus an inexpensive configuration can be implemented.

According to the invention, the work vehicle further can include a rear ROPS member attached to a rear wheel axle housing and the transmission mechanism.

According to the invention, a first plate and a second plate can be fixed to the rear ROPS member, the first plate can be attached to the transmission mechanism, and the second plate can be attached to the rear wheel axle housing.

Accordingly, since the rear ROPS member can be attached to the rear wheel axle housing and the transmission mechanism, the rear ROPS member can be more firmly attached.

According to the invention, it is possible to provide a work vehicle on which a ROPS member can be more firmly attached.

An embodiment of the invention will be described in detail with reference to the drawings.

Some components may not be illustrated in the drawings or may be transparently illustrated or omitted, and the same applies hereinafter.

Here, <FIG> is a left side view of the agricultural tractor according to the embodiment of the invention, <FIG> is a perspective view of the vicinity of a front ROPS member <NUM> and the vicinity of a rear ROPS member <NUM> of the agricultural tractor according to the embodiment of the invention, <FIG> is a left side view of the vicinity of the front ROPS member <NUM> of the agricultural tractor according to the embodiment of the invention, <FIG> is a left side view of the vicinity of the rear ROPS member <NUM> of the agricultural tractor according to the embodiment of the invention, and <FIG> is a front view illustrating a part of the front ROPS member <NUM> and a part of the rear ROPS member <NUM> of the agricultural tractor according to the embodiment of the invention.

The agricultural tractor according to the present embodiment is an example of a work vehicle in the invention.

An engine <NUM> is provided inside a bonnet <NUM> at a front portion of a vehicle body <NUM>.

Rotational power of the engine <NUM> is transmitted via various clutches inside a transmission case provided below a floor <NUM> of an operation unit <NUM>. More specifically, the rotational power speed-changed by a main transmission and an auxiliary transmission is transmitted to a pair of left and right front wheels 40f and a pair of left and right rear wheels 40b.

A steering wheel <NUM> is provided behind the engine <NUM> together with a dashboard cover, a meter panel, and a forward-reverse lever.

A driver seat <NUM> is provided behind the steering wheel <NUM>.

A brake pedal disconnection pedal and a clutch pedal are disposed on a left side of the floor <NUM>. A pair of left and right pedals including a brake pedal and an accelerator pedal are disposed on a right side of the floor <NUM>.

A work machine is mounted on a rear portion of the vehicle body <NUM> using, for example, a three-point link mechanism.

A front frame <NUM> attached to the engine <NUM> which generates power using fuel is a frame that supports the front wheels 40f.

For example, the front frame <NUM> includes a front side frame attached to the engine <NUM>, and the front side frame supports a front wheel axle housing functioning as a front wheel axle case that incorporates an axle of the front wheels 40f and supports a front-portion load of the vehicle body <NUM>.

The transmission mechanism <NUM> attached to the engine <NUM> is a mechanism that transmits the power generated by the engine <NUM> to the rear wheels 40b.

For example, the transmission mechanism <NUM> includes the transmission case attached to the engine <NUM>. The transmission case incorporates a power transmission device that transmits the power of the engine <NUM> to driving wheels.

(<NUM>) Next, the configuration and the operation of the agricultural tractor according to the embodiment of the invention will be described more specifically mainly with reference to <FIG>.

Here, <FIG> is a perspective view of the vicinity of the front ROPS member <NUM> of the agricultural tractor according to the embodiment of the invention, <FIG> is a plan view of the vicinity of the front ROPS member <NUM> of the agricultural tractor according to the embodiment of the invention, and <FIG> is a front view illustrating a part of the front ROPS member <NUM> of the agricultural tractor according to the embodiment of the invention.

The front ROPS member <NUM> is attached to the front frame <NUM> and a front portion 70f of the transmission mechanism <NUM>.

For example, the front ROPS member <NUM> includes a front ROPS central arch member 80C which serves as an upper frame, and front ROPS left pillar member <NUM> and front ROPS right pillar member 80R which serve as lower frames, and the rear ROPS member <NUM> includes a rear ROPS central arch member 90C which serves as an upper frame and a rear ROPS left pillar member <NUM> and a rear ROPS right pillar member 90R which serve as lower frames.

The front ROPS member <NUM> in front of the driver seat <NUM> is erected between the front wheels 40f and the rear wheels 40b as a safety frame capable of securing a survival space to protect a driver in the driver seat <NUM> even when the vehicle body <NUM> overturns.

Of course, the rear ROPS member <NUM> whose ROPS base portion is attached to a rear wheel axle housing 41b functioning as a rear wheel axle case incorporating an axle of the rear wheels 40b for firmly supporting an entire load of the vehicle body <NUM> and which is erected behind the driver seat <NUM> is also effective as a safety frame, which is required to maintain a frame shape by preventing frame deformation even when the rear ROPS member <NUM> bears an entire weight of the vehicle body <NUM> due to overturning. However, when the agricultural tractor travels in a narrow space such as an orchard and a cultivation greenhouse, it is often desirable for the driver to perform a traveling operation while monitoring that the safety frame does not come into contact with trees in the orchard and a ceiling of the cultivation greenhouse, and thus a demand for the front ROPS member <NUM> erected in front of the driver seat <NUM> is not low.

The front ROPS member <NUM>, which is attached not only to the front frame <NUM> but also to the front portion 70f of the transmission mechanism <NUM>, has a firm vehicle body attachment and fixing configuration from the front frame <NUM> to the transmission mechanism <NUM>, and thus, similarly to the rear ROPS member <NUM>, a frame shape can be maintained by preventing frame deformation even when the front ROPS member <NUM> bears the entire weight of the vehicle body <NUM> due to the overturning.

The front ROPS member <NUM> includes the front ROPS left pillar member <NUM> and the front ROPS right pillar member 80R that are erected on a left side and a right side in a vehicle body left-right direction, respectively.

A front ROPS left plate <NUM> is fixed to a lower end of the front ROPS left pillar member <NUM>, a front portion 81Lf of the front ROPS left plate <NUM> is attached to the front frame <NUM>, and a rear portion 81Lb of the front ROPS left plate <NUM> is attached to the front portion 70f of the transmission mechanism <NUM>.

More specifically, fastening of three bolts in which a bolt shaft direction is the vehicle body left-right direction is used in attachment of the front portion 81Lf of the front ROPS left plate <NUM>, and fastening of four bolts in which a bolt shaft direction is the vehicle body left-right direction is used in attachment of the rear portion 81Lb of the front ROPS left plate <NUM>.

By using the front frame <NUM> that functions as a front wheel axle bracket and the front portion 70f of the transmission mechanism <NUM> that functions as a clutch housing, a configuration is adopted in which the front ROPS left plate <NUM> in the front ROPS left pillar member <NUM> of the front ROPS member <NUM> which is also referred to as a center ROPS, is attached at two positions, and thus strength is improved along with load distribution.

A front ROPS right plate 81R is fixed to a lower end of the front ROPS right pillar member 80R, a front portion 81Rf of the front ROPS right plate 81R is attached to the front frame <NUM>, and a rear portion 81Rb of the front ROPS right plate 81R is attached to the front portion 70f of the transmission mechanism <NUM>.

More specifically, fastening of three bolts in which a bolt shaft direction is the vehicle body left-right direction is used in attachment of the front portion 81Rf of the front ROPS right plate 81R, and fastening of four bolts in which a bolt shaft direction is the vehicle body left-right direction is used in attachment of the rear portion 81Rb of the front ROPS right plate 81R.

By using the front frame <NUM> that functions as the front wheel axle bracket and the front portion 70f of the transmission mechanism <NUM> that functions as the clutch housing, a configuration is adopted in which the front ROPS right plate 81R in the front ROPS right pillar member 80R of the front ROPS member <NUM> which is also referred to as the center ROPS, is attached at two positions, and thus the strength is improved along with the load distribution.

Left spacer plates <NUM> each having a thickness corresponding to a gap between the front portion 81Lf of the front ROPS left plate <NUM> and the front frame <NUM> are inserted.

By simply changing thicknesses of the two left spacer plates <NUM> between the front ROPS left plate <NUM> functioning as an attachment portion of the front ROPS member <NUM> which is also referred to as the center ROPS, and the front frame <NUM> functioning as the front wheel axle bracket, a flexible measure against a width of the front wheel axle bracket in the vehicle body left-right direction, which varies depending on a tractor model, is implemented, and thus sharing of the center ROPS is promoted. By attaching the front ROPS left plate <NUM>, the left spacer plates <NUM>, and the front frame <NUM> by bolt fastening without directly affecting the engine <NUM>, generation of a large load on the engine <NUM> is prevented. Of course, the front ROPS left plate <NUM> may be attached, by bolting, to the left spacer plates <NUM> fixed to the front frame <NUM> by welding or the like.

Right spacer plates 82R each having a thickness corresponding to a gap between the front portion 81Rf of the front ROPS right plate 81R and the front frame <NUM> are inserted.

By simply changing thicknesses of the two right spacer plates 82R between the front ROPS right plate 81R functioning as an attachment portion of the front ROPS member <NUM> which is also referred to as the center ROPS, and the front frame <NUM> functioning as the front wheel axle bracket, a flexible measure against the width of the front wheel axle bracket in the vehicle body left-right direction, which varies depending on the tractor model, is implemented, and thus sharing of the center ROPS is promoted. By attaching the front ROPS right plate 81R, the right spacer plates 82R, and the front frame <NUM> by bolt fastening without directly affecting the engine <NUM>, generation of a large load on the engine <NUM> is prevented. Of course, the front ROPS right plate 81R may be attached, by bolting, to the right spacer plates 82R fixed to the front frame <NUM> by welding or the like.

The front ROPS left pillar member <NUM> and the front ROPS right pillar member 80R are members obtained by dividing a U-shaped pipe member M in the vicinity of a center C of the U shape.

More specifically, the front ROPS left pillar member <NUM> and the front ROPS right pillar member 80R serving as the lower frames of the front ROPS member <NUM> are in a shape in which a U-shaped steel pipe bent at one position is divided into a left side and a right side. The bending of the lower frames is only performed once, and thus a processing cost and the like are reduced.

In this manner, since the front ROPS left pillar member <NUM> and the front ROPS right pillar member 80R that function as the lower frames of the center ROPS are collectively implemented by using the steel pipe with a large bending degree, an unnecessary portion of the pipe member M in the vicinity of the center C, which is a portion removed along with the division, is reduced.

(<NUM>) Next, the configuration and the operation of the agricultural tractor according to the embodiment of the invention will be described further more specifically mainly with reference to <FIG>.

<FIG> is a perspective view of the vicinity of the rear ROPS member <NUM> of the agricultural tractor according to the embodiment of the invention, and <FIG> and <FIG> are left side views (part <NUM> and part <NUM>) of the vicinity of the rear ROPS member <NUM> of the agricultural tractor according to the embodiment of the invention.

The rear ROPS member <NUM> is attached to the rear wheel axle housing 41b and a rear portion 70b of the transmission mechanism <NUM>.

The rear ROPS member <NUM> includes the rear ROPS left pillar member <NUM> and the rear ROPS right pillar member 90R that are erected on the left side and the right side in the vehicle body left-right direction, respectively.

A rear ROPS left L-shaped plate <NUM> and a rear ROPS left I-shaped plate <NUM> are fixed to a lower end of the rear ROPS left pillar member <NUM>, a left portion of the rear ROPS left L-shaped plate <NUM> and the rear ROPS left I-shaped plate <NUM> are attached to the rear wheel axle housing 41b, and a rear portion of the rear ROPS left L-shaped plate <NUM> is attached to the rear portion 70b of the transmission mechanism <NUM>.

More specifically, fastening of two bolts in which a bolt shaft direction is the vehicle body left-right direction is used in attachment of the left portion of the rear ROPS left L-shaped plate <NUM>, fastening of two bolts in which a bolt shaft direction is a vehicle body front-rear direction is used in attachment of the rear portion of the rear ROPS left L-shaped plate <NUM>, and fastening of three bolts in which a bolt shaft direction is the vehicle body left-right direction is used in attachment of the rear ROPS left I-shaped plate <NUM>.

The rear ROPS left pillar member <NUM> functioning as the lower frame of the rear ROPS member <NUM> which is also referred to as a rear ROPS, is attached to the rear wheel axle housing 41b functioning as a rear axle housing at one position in the vicinity of a brake mechanism by using the rear ROPS left L-shaped plate <NUM>, and is not only attached to the rear portion 70b of the transmission mechanism <NUM> functioning as a rear transmission case at one position in the vicinity of an outer wall of the case, but also attached to the rear wheel axle housing 41b at one position in the vicinity of a wheel shaft through hole by using the rear ROPS left I-shaped plate <NUM>. In this manner, a configuration is adopted in which the rear ROPS left L-shaped plate <NUM> and the rear ROPS left I-shaped plate <NUM> are attached at three positions in total, and thus the strength is improved along with the load distribution.

A rear ROPS right L-shaped plate 91R and a rear ROPS right I-shaped plate 92R are fixed to a lower end of the rear ROPS right pillar member 90R, a right portion of the rear ROPS right L-shaped plate 91R and the rear ROPS right I-shaped plate 92R are attached to the rear wheel axle housing 41b, and a rear portion of the rear ROPS right L-shaped plate 91R is attached to the rear portion 70b of the transmission mechanism <NUM>.

More specifically, fastening of two bolts in which a bolt shaft direction is the vehicle body left-right direction is used in attachment of the right portion of the rear ROPS right L-shaped plate 91R, fastening of two bolts in which a bolt shaft direction is the vehicle body front-rear direction is used in attachment of the rear portion of the rear ROPS right L-shaped plate 91R, and fastening of three bolts in which a bolt shaft direction is the vehicle body left-right direction is used in attachment of the rear ROPS right I-shaped plate 92R.

The rear ROPS right pillar member 90R functioning as the lower frame of the rear ROPS member <NUM> which is also referred to as the rear ROPS, is attached to the rear wheel axle housing 41b functioning as the rear axle housing at one position in the vicinity of the brake mechanism by using the rear ROPS right L-shaped plate 91R, and is not only attached to the rear portion 70b of the transmission mechanism <NUM> functioning as the rear transmission case at one position in the vicinity of the outer wall of the case, but also attached to the rear wheel axle housing 41b at one position in the vicinity of the wheel shaft through hole by using the rear ROPS right I-shaped plate 92R. In this manner, a configuration is adopted in which the rear ROPS right L-shaped plate 91R and the rear ROPS right I-shaped plate 92R are attached at three positions in total, and thus the strength is improved along with the load distribution.

Claim 1:
A work vehicle comprising:
a front frame (<NUM>) configured to support a front wheel (40f);
a transmission mechanism (<NUM>) configured to transmit power; and
a front ROPS member (<NUM>), wherein
the front ROPS member (<NUM>) is fixed to a front ROPS left plate (<NUM>) and a front ROPS right plate (81R), characterised in that
each of the front ROPS left plate (<NUM>) and the front ROPS right plate (81R) is attached both to the transmission mechanism (<NUM>) and to the front frame (<NUM>).