Structure for attaching rear work machine to tractor

A structure for attaching a rear work machine to a tractor is provided. The tractor has a vehicle body which is provided with right and left rear work machine connection bodies, each having upper and lower connection portions. The rear work machine includes a base frame with an operator's seat, which is provided with right and left attaching plates, each having upper and lower engagement portions. The rear work machine can be attached to the tractor by connecting the upper and lower engagement portions to the upper and lower connection portions, respectively. The attaching structure includes: a rear work machine attaching spacer disposed between the rear work machine connection body and the corresponding attaching plate, the rear work machine attaching spacer including: a fixing portion for fixing to the attaching plate; and the upper and lower spacer engagement portions for removably connecting the upper and lower connection portions, respectively.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a structure for attaching a rear work machine to a tractor.

2. Description of the Related Art

As a rear work machine attaching structure, which is for attaching a rear work machine, such as backhoe, to the tractor, the following structure has been known. Specifically in this rear work machine attaching structure, a vehicle body of the tractor is provided on lateral sides thereof with a pair of right and left rear work machine connection bodies protruding rearward, each of which has an upper connection portion and a lower connection portion, while a base frame of the rear work machine is provided with a pair of right and left attaching plates, each of which has an upper engagement portion and a lower engagement portion. By respectively connecting the upper engagement portion and the lower engagement portion of the attaching plate to the upper connection portion and the lower connection portion of the corresponding attaching frame, the rear work machine is coupled to the tractor (see, for example, Japanese unexamined patent applications No. 2008-201328 and No. 2007-261323).

When a rear work machine, such as backhoe, is attached to the tractor having a cabin mounted on a rear portion of the tractor vehicle body, the following problem may arise. Specifically, since the cabin has a rear wall, it is difficult to make the orientation of the front-facing seat inside the cabin switchable to rear-facing, for the purpose of using the same seat also for an operation of the rear work machine. Accordingly, it is necessary to mount a separate operator's seat facing rearward on a front portion of the base frame of the rear work machine.

In order to prevent the rear wall of the cabin from interfering with the operator's seat for the rear work machine, it is necessary to attach the rear work machine, such as a backhoe, rearward away from the tractor vehicle body to a large degree, as compared with a case where the rear work machine is attached to a tractor having a ROPS or the like, instead of the cabin, in the rear portion of the tractor vehicle body. In this case, special members have been conventionally used as the right and left attaching plates each having the upper and lower engagement portions, which extend frontward to a large degree from the base frame of the rear work machine.

Therefore, conventionally, there has been a necessity to use the special attaching plate or the like in the rear work machine, such as backhoe, and thus the conventional rear work machine or the attaching plate thereof with the rear-facing operator's seat to be attached to the tractor with the ROPS or the like cannot be used as-is for the tractor with the cabin, resulting in poor cost efficiency. Accordingly, it would be desirable to provide a structure for attaching a rear work machine to a tractor that can solve the above-mentioned problem.

SUMMARY OF THE INVENTION

The present invention provides a structure for attaching a rear work machine a tractor, the tractor including: a tractor vehicle body; and a cabin mounted on a rear portion of the tractor vehicle body, the tractor vehicle body being provided with a pair of right and left rear work machine connection bodies protruding rearward, each of which has an upper connection portion and a lower connection portion, the rear work machine including: a base frame; and an operator's seat mounted on a front portion of the base frame, the base frame being provided with a pair of right and left attaching plates, each of which has an upper engagement portion and a lower engagement portion, and the rear work machine being configured to be attached to the tractor by respectively connecting the upper engagement portion and the lower engagement portion of the attaching plate to the upper connection portion and the lower connection portion of the corresponding rear work machine connection body, the structure including: a rear work machine attaching spacer disposed between the rear work machine connection body and the corresponding attaching plate, the rear work machine attaching spacer including: a fixing portion configured to be fixed to the attaching plate; an upper spacer engagement portion configured to be removably connected to the upper connection portion of the rear work machine connection body; and a lower spacer engagement portion configured to be removably connected to the lower connection portion of the rear work machine connection body.

In the configuration described above, it is preferable that, in the rear work machine attaching spacer, a positional relationship among the fixing portion, the upper spacer engagement portion and the lower spacer engagement portion is set so that, when the fixing portion is fixed to the attaching plate, the upper spacer engagement portion is positioned frontward of the upper engagement portion of the attaching plate, and at the same time the lower spacer engagement portion is positioned frontward of the lower engagement portion of the attaching plate.

In the configuration described above, it is preferable that the fixing portion in a form of a plate is overlapped with and fastened to the attaching plate with fastening means, the lower connection portion is shaped as a recess with an upward opening, the lower spacer engagement portion is formed of a connecting shaft configured to be removably engaged with the lower connection portion from above, in a manner similar to that for the lower engagement portion of the rear work machine, and the upper spacer engagement portion is formed of a boss into which a connecting pin can be inserted, in a manner similar to that for the upper engagement portion of the rear work machine, and the upper connection portion and the upper spacer engagement portion are removably connected to each other by the connecting pin inserted into the upper connection portion and the upper spacer engagement portion.

In the configuration described above, it is preferable that the fixing portion includes: an upper spacer connection portion positioned rearward of the upper spacer engagement portion; and a lower spacer connection portion positioned rearward of the lower spacer engagement portion, and the fixing portion is fixed to the attaching plate by connecting the upper spacer connection portion to the upper engagement portion of the attaching plate, and connecting the lower spacer connection portion to the lower engagement portion of the attaching plate.

According to the present invention, the spacer for attaching a rear work machine is disposed between the rear work machine connection body and the attaching plate. The spacer for attaching a rear work machine includes: the fixing portion configured to be fixed to the attaching plate; the upper spacer engagement portion configured to be removably connected to the upper connection portion of the rear work machine connection body; and the lower spacer engagement portion configured to be removably connected to the lower connection portion of the rear work machine connection body. Therefore, the conventional rear work machine or the attaching plate thereof configured to be attached to the tractor with no cabin can be used as-is, so that a rear work machine, such as backhoe, having a rear-facing operator's seat can be applied to a tractor having the cabin. As a result, there is no need to use a special attaching plate in the rear work machine, such as backhoe, and the backhoe or the attaching plate can be used as-is, leading to cost saving. Moreover, since the rear work machine attaching spacer is connected to the rear work machine connection body, the rear work machine connection body can be conveniently used as-is, and since the rear work machine attaching spacer is fixed to the attaching plate of the rear work machine, the attaching plate can be conveniently used as-is.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIG. 1, a work vehicle1is what is called a tractor, front loader and backhoe (TLB). A tractor vehicle body2is reinforced with a pair of right and left attaching frames3, and to a portion frontward of an intermediate portion of the frame3, a front loader4as a front work machine is removably attached, while to a rear portion of the tractor vehicle body2, a backhoe7as a rear work machine is removably attached.

The tractor vehicle body2includes an engine9, a clutch housing10, a connection case11, and a transmission case12, all connected in series in a front-rear direction. A front wheel frame15configured to suspend a front axle case of the front wheels13protrudes frontward from the engine9, and a rear axle case16protrudes laterally outward from a rear portion of the transmission case12. Rear wheels20are supported by a rear axle18protruding laterally outward from the rear axle case16.

Though not shown, on an upper portion of the transmission case12, a hydraulic power unit for elevating the work machine is mounted. When the work machine, such as rotary tiller, is attached instead of the backhoe (rear work machine)7to a rear portion of the tractor vehicle body2, the work machine elevating hydraulic power unit lifts and lowers the work machine. Above the hydraulic power unit, a front-facing driver's seat and operation unit are provided, and from an area below the driver's seat to the operation unit, a floor sheet is provided, to whose lateral sides are attached rear wheel fenders22. On the rear portion of the tractor vehicle body2, a cabin24is mounted so as to surround the driver's seat and the operation unit.

The front loader (front work machine) includes a pair of right and left masts26, a pair of right and left booms27and a bucket28. A base portion of the boom27is supported vertically swingably by an upper portion of the corresponding mast26, and the bucket28is pivotally supported by end portions of the right and left booms27in such a manner that the bucket28can perform scooping and dumping. The boom27is configured to be actuated hydraulically by a boom cylinder29, and the bucket28is configured to be actuated hydraulically by a bucket cylinder30.

The mast26is fitted from above into a mast receiving member31of a front loader attaching body33to thereby engage a lower portion of the mast26with the mast receiving member31, and an intermediate portion of the mast26is locked to the mast receiving member31with a lock pin32. Accordingly, the front loader4not in use can be removed from the attaching body33by pulling out the lock pin32.

In addition to the mast receiving member31, the attaching body33includes a pair of right and left mounting members34and a support tube36. The pair of right and left mounting members34are attached to members forming the tractor vehicle body2, such as the engine9and the clutch housing10, the support tube36is protruding laterally outward from the mounting member34, and the mast receiving member31is protruding upward from the support tube36.

The attaching frame3is formed of a pair of right and left plates whose thickness is oriented in a lateral direction, and longwise arranged in the front-rear direction on the corresponding right and left lateral sides of the tractor vehicle body2. Each of the right and left attaching frames3has a front attaching portion39and a rear attaching portion40, with the former being connected and fixed by bolts or the like to a bracket41or the like of the attaching body33for attaching the front loader4, and the latter being fixed to the tractor vehicle body2by bolts or the like, in the vicinity of the rear axle18.

Rearward of the rear attaching portion40of each of the right and left attaching frames3, a rear work machine connection body43is provided. The rear work machine connection body43has an upper connection portion45and a lower connection portion46, protruding rearward from the tractor vehicle body2.

As shown inFIGS. 2-4, the upper connection portion45is formed of a boss having an insertion hole, provided in a rear upper portion of the attaching frame3, into which a connecting pin48can be inserted. To a rear lower portion of the attaching frame3is fixed a receiving member50having a recess with an upward opening, providing the lower connection portion46.

Referring toFIGS. 1-4, the backhoe (rear work machine)7includes: a pair of right and left attaching plates53vertically standing frontward of a base frame51; a top panel54which is connected to upper end portions of the right and left attaching plates53and serves as a step oriented rearward; and a lower plate55connected to lower end portions of the right and left attaching plates53. By a rear portion of the base frame51, a swing bracket57is supported swingably about a vertical shaft. On a front portion of the top panel54, a rear-facing operator's seat59is provided and an operating device60is mounted rearward of the operator's seat59. On right and left sides of the base frame51, outriggers (stabilizers)61hydraulically driven are provided.

The swing bracket57is laterally swingable by a single swing cylinder64, and by the swing bracket57, base portions of a boom65and boom cylinder66are pivotally supported. The boom65is vertically swingable by the boom cylinder66. An arm67is pivotally supported by an end portion of the boom65and is vertically swingable by an arm cylinder68. A bucket69is pivotally supported by an end portion of the arm67with a bucket cylinder70in such a manner that the bucket69can perform scooping and dumping.

As shown inFIGS. 2-4, in upper and lower portions of each of the pair of right and left attaching plates53of the backhoe7, there are provided an upper engagement portion71and a lower engagement portion72, which are removably connected to the upper connection portion45and the lower connection portion46, respectively, of the corresponding rear work machine connection body43in a rear end portion of the attaching frame3. With this configuration, the backhoe7can be attached to and removed from the tractor vehicle body2.

The upper engagement portion71is formed of a member having a squared U-shape as seen from above, which is fixed to both the attaching plate53and the top panel54by welding and has a boss with an insertion hole. By concentrically arranging the insertion holes of the upper engagement portion71and the upper connection portion45and inserting the connecting pin48thereinto, the upper engagement portion71and the upper connection portion45can be connected.

The lower engagement portion72is formed of a connecting shaft penetrating through and fixed to the attaching plate53, and configured to be removably engaged with the lower connection portion46from above. For connection, first the lower engagement portion72is engaged with the lower connection portion46, the base frame51is rotated about the lower engagement portion72, the upper engagement portion71and the upper connection portion45are faced to each other (the insertion holes are concentrically arranged), and then the connecting pin48is inserted into the through holes.

Between the right (left) rear work machine connection body43and the right (left) attaching plate53, a right (left) spacer75for attaching the rear work machine is disposed. Each of the rear work machine attaching spacers75includes: a fixing portion77configured to be fixed to the attaching plate53; an upper spacer engagement portion78configured to be removably connected to the upper connection portion45of the rear work machine connection body43; and a lower spacer engagement portion79configured to be removably connected to the lower connection portion46of the rear work machine connection body43.

More specifically, as shown inFIGS. 5-8, the rear work machine attaching spacer75includes: an outer plate75a; an inner plate75b; a connection body75cconnecting the plates75a,75b; a support75din a squared U-shape fixed to upper end portions of the plates75a,75b; and a lower support plate75eprotruding from the inner plate75b. A rear portion of the inner plate75bis shaped into a plate which serves as the fixing portion77. The support75dis provided with the upper spacer engagement portion78which is formed of a boss into which the connecting pin48can be inserted, like the upper engagement portion71. The lower spacer engagement portion79is provided between the outer plate75aand the lower support plate75eat lower end portions thereof, and is formed of a connecting shaft configured to be removably engaged with the lower connection portion46, like the lower engagement portion72of the backhoe7.

The fixing portion77is overlapped with and removably fastened to the attaching plate53with fastening means, such as bolts. The upper connection portion45and the upper spacer engagement portion78are arranged in such a manner that the insertion holes thereof are contiguously aligned, into which the connecting pin48is inserted. In this manner, the upper connection portion45and the upper spacer engagement portion78are removably connected to each other. The lower spacer engagement portion79is removably engaged with the lower connection portion46from above.

A positional relationship among the fixing portion77, the upper spacer engagement portion78and the lower spacer engagement portion79are set in such a manner that, when the fixing portion77is fixed to the attaching plate53, the upper spacer engagement portion78is positioned frontward of the upper engagement portion71of the attaching plate53, and at the same time the lower spacer engagement portion79is positioned frontward of the lower engagement portion72of the attaching plate53.

It should be noted that the support75dof the rear work machine attaching spacer75is provided with a pin holding portion80configured to engage with a retaining pin inserted into an end portion of the connecting pin48.

According to the above-described embodiment, the rear work machine attaching spacer75disposed between the rear work machine connection body43on a tractor vehicle body2side and the attaching plate53on a backhoe7side has: the fixing portion77configured to be fixed to the attaching plate53; the upper spacer engagement portion78configured to be removably connected to the upper connection portion45of the rear work machine connection body43; the lower spacer engagement portion79configured to be removably connected to the lower connection portion46of the rear work machine connection body43. When the fixing portion77is fixed to the attaching plate53, the upper spacer engagement portion78is positioned frontward of the upper engagement portion71of the attaching plate53, and at the same time the lower spacer engagement portion79is positioned frontward of the lower engagement portion of the attaching plate53. Therefore, by connecting the upper spacer engagement portion78of the rear work machine attaching spacer75fixed to the attaching plate53to the upper connection portion45of the rear work machine connection body43, and at the same time by connecting the lower spacer engagement portion79of the rear work machine attaching spacer75fixed to the attaching plate53to the lower connection portion46of the rear work machine connection body43, the attaching position of the backhoe7can be make much rearward relative to the tractor as compared with a case where the backhoe7is attached to the tractor vehicle body2by directly connecting the attaching plate53of the backhoe7to the rear work machine connection body43of the tractor vehicle body2. Accordingly, even when the cabin24is mounted on the tractor and the rear-facing operator's seat59is mounted on the backhoe7, the cabin24is prevented from being interfered with the operator's seat59. Therefore, the conventional backhoe7or the attaching plate53thereof configured to be attached to the tractor having a ROPS or the like instead of the cabin24can be used as-is, and the rear work machine, such as the backhoe7, having the rear-facing operator's seat59can be applied to the tractor having the cabin24. As a result, there is no need to use a special attaching plate53in the rear work machine, such as the backhoe7, and the backhoe7or the attaching plate53can be used as-is, leading to cost saving. Moreover, since the rear work machine attaching spacer75is connected to the rear work machine connection body43, the upper connection portion45and the lower connection portion46of the rear work machine connection body43can be conveniently used as-is, and since the rear work machine attaching spacer75is fixed to the attaching plate53of the rear work machine, the attaching plate53can be conveniently used as-is.

FIGS. 9 to 12show another embodiment of the present invention, in which the right (left) rear work machine attaching spacers75between the right (left) rear work machine connection body43and the right (left) attaching plate53includes: the fixing portion77configured to be fixed to the attaching plate53; the upper spacer engagement portion78configured to be removably connected to the upper connection portion45of the rear work machine connection body43; and the lower spacer engagement portion79configured to be removably connected to the lower connection portion46of the rear work machine connection body43. The fixing portion77of the rear work machine attaching spacer75includes: an upper spacer connection portion81positioned rearward of the upper spacer engagement portion78; and a lower spacer connection portion82positioned rearward of the lower spacer engagement portion79.

More specifically, the rear work machine attaching spacer75includes: the outer plate75a; the inner plate75b; the connection body75cconnecting the plates75a,75b; the support75din a squared U-shape fixed to the upper end portions of the plates75a,75b; and the lower support plate75eprotruding from the inner plate75b. Each of the rear portions of the outer plate75aand the inner plate75bis shaped into a plate which serves as the fixing portion77. The support75dis provided with the upper spacer engagement portion78which is formed of a boss into which the connecting pin48can be inserted, like the upper engagement portion71. The lower spacer engagement portion79is provided between the outer plate75aand the lower support plate75eat lower end portions thereof, and is formed of a connecting shaft configured to be removably engageable with the lower connection portion46, like the lower engagement portion72of the backhoe7.

A rear upper portion of the outer plate75ais provided with the upper spacer connection portion81which is formed of a boss having an insertion hole into which the connecting pin48can be inserted, like the upper connection portion45of the rear work machine connection body43. The lower spacer connection portion82is provided between the plates75a,75bat lower rear end portions thereof, and is formed of a boss having an insertion hole into which the lower engagement portion (shaft portion)72of the attaching plate53can be inserted. The lower engagement portion72of the attaching plate53is configured to be removably connected to the upper spacer connection portion81, through the insertion of the lower engagement portion72into the lower spacer connection portion82. In addition, the fixing portion77is configured to be removably fixed to the attaching plate53, through the connection of the upper engagement portion71of the attaching plate53to the upper spacer connection portion81as well as the connection of the lower engagement portion72of the attaching plate53to the lower spacer connection portion82.

Other features are the same as those in the embodiment described above, and likewise, the conventional backhoe7or the attaching plate53thereof configured to be attached to the tractor having a ROPS or the like instead of the cabin24can be used as-is, and the rear work machine, such as the backhoe7, having the rear-facing operator's seat59can be applied to the tractor having the cabin24. As a result, there is no need to use a special attaching plate53in the rear work machine, such as the backhoe7, and the backhoe7or the attaching plate53can be used as-is, leading to cost saving. Moreover, since the rear work machine attaching spacer75is connected to the rear work machine connection body43, the rear work machine connection body43can be conveniently used as-is, and since the rear work machine attaching spacer75is fixed to the attaching plate53of the rear work machine, the attaching plate53can be conveniently used as-is.

It should be noted that, in the embodiments described above, the present invention is applied to the work vehicle called a tractor-front loader-backhoe (TLB). However, the work vehicle to which the present invention can be applied is not limited to the TLB, and alternatively, it is applicable to a work vehicle in which the tractor vehicle body has only a backhoe attached to a rear portion, or to a work vehicle in which a rear work machine other than the backhoe is attached to a rear portion of the tractor vehicle body.