JP5456334B2 - Front work machine - Google Patents

Description

  The present invention relates to a front work machine that is mounted on a work vehicle such as a tractor and performs various operations in front of the work vehicle.

  As is well known, a working vehicle such as a tractor may be equipped with a so-called front working machine such as a dozer that performs leveling or snow removal in front of the work vehicle, or a loader that performs agricultural work, cargo handling, transporting work, or the like. As this type of front work machine, for example, a construction shown in FIG. 8 is known. The front work machine 51 shown in the figure includes a lift arm 52 that is rotatably supported with respect to the work vehicle 50, a work attachment 53 such as a bucket attached to the tip of the lift arm 52, and a lift cylinder 54. A hydraulic actuator is provided. A hydraulic pipe (not shown) extending from the main body of the work vehicle 50 is connected to the lift cylinder 54, and the cylinder rod of the lift cylinder 54 is extended and shortened by the hydraulic oil supplied to the oil chamber of the lift cylinder 54 via the hydraulic pipe. To do. The lift arm 52 is rotated (lifted / lowered) with respect to the work vehicle 50 by the extension and shortening operations of the cylinder rod of the lift cylinder 54.

  As described above, since this type of front work machine rotates with respect to the work vehicle, the hydraulic piping extending from the main body of the work vehicle and having the tip connected to the hydraulic actuator should follow the operation of the front work machine. Need to be rotated. Accordingly, the hydraulic piping is configured by a bendable hydraulic hose and is often fixed to the lift arm by a fixture such as a binding band or a fixture (see, for example, Patent Document 1).

JP-A-8-226138

  In the above-described conventional configuration, when the front work machine is mounted on the work vehicle, the hydraulic piping must be fixed to the lift arm using a fixing tool such as a binding band, while the front work machine is detached from the work vehicle. To fix it, the fixture must be cut. For this reason, there is a problem that the piping work of the hydraulic piping, and consequently the attaching / detaching work of the front working machine is complicated.

  Moreover, with the traveling operation of the work vehicle, earth and sand, snow, and the like are scattered particularly on the lift arm adjacent to the work attachment. At this time, as described above, if the hydraulic piping is fixed to the lift arm and exposed to the outside, the hydraulic piping may be damaged by scattered materials such as earth and sand. In addition, even if the hydraulic piping is not directly damaged by the scattered matter, the scattered matter accumulates on the hydraulic piping, and the hydraulic piping is likely to be deteriorated or damaged by receiving such an external load. There's a problem.

  An object of the present invention is to provide a front work machine that simplifies the piping work of hydraulic piping and can be easily attached to and detached from a work vehicle.

In order to solve the above-described problems, the present invention includes a lift arm having a work attachment attached to the tip thereof, and a hydraulic actuator that pivots the lift arm up and down relative to the agricultural tractor . The hydraulic actuator includes the agricultural tractor. in front work machine hydraulic pipe is connected extending from the lift arm is a cylindrical body formed by performing plastic working on a single metal pipe, wherein the hydraulic pipe can be inserted Provide front work equipment.

  If said structure is employ | adopted, the part extended along a lift arm among hydraulic piping extended from a work vehicle can be penetrated in a lift arm. Therefore, since the operation range of the hydraulic piping can be regulated by the inner wall surface of the lift arm, at least a portion extending along the lift arm of the hydraulic piping is lifted by using a fixture such as a binding band as in the prior art. There is no need to fix it to the arm. Accordingly, the piping work of the hydraulic piping can be simplified.

  Also, if the hydraulic piping is inserted into the lift arm, even if dirt or the like is scattered or accumulated in the lift arm with the traveling operation of the work vehicle, at least the portion of the hydraulic piping that is inserted into the lift arm is There is no external load. Thereby, the possibility that the hydraulic piping is deteriorated or damaged can be reduced, and the labor required for the maintenance of the hydraulic piping can be reduced.

  Due to the characteristics of this type of front work machine, a vertical bending load acts mainly on the lift arm. Therefore, it is desirable that the lift arm has an oval cross section in which a long axis is arranged along the vertical direction (vertical direction) of the work vehicle. This is because the rigidity with respect to the bending load can be increased and the reliability of the front working machine can be improved. The term “oval” as used herein means a closed curve that is not a perfect circle and has at least one line-symmetric part. For example, an oval, a rounded rectangle (two parallel lines of two equal lengths and two It is a concept including an ellipse.

  Although the cylindrical (hollow) lift arm can be composed of a plurality of cylinders joined together by welding or the like, in this case, welding marks are formed in a protruding shape inside the lift arm. . This may hinder the insertion work of the hydraulic piping and may damage the hydraulic piping during insertion. In view of such a situation, it is desirable that the cylindrical lift arm is made of a single pipe material.

  The lift arm of the front work machine can be detachably attached to a rotation support portion provided on the work vehicle. At this time, if the lift arm is attached to the rotation support portion using a connection pin for connecting the lift arm to the rotation support portion and a retaining pin for preventing the connection pin from coming off, the two pins are inserted. By doing so, it is possible to complete the attachment of the lift arm to the rotation support portion (work vehicle) while preventing the lift arm from being detached from the rotation support portion. On the contrary, the lift arm can be detached from the swinging support portion simply by removing the connecting pin after removing the retaining pin. Therefore, it is not necessary to use a tool when attaching / detaching the lift arm to / from the work vehicle, and the attaching / detaching work of the front work machine to / from the work vehicle can be simplified.

  In addition, the mounting structure of the lift arm with respect to the rotation support portion described above is not only a front work machine having a cylindrical lift arm (a lift arm having a hollow portion) but also a plate-like lift arm (having a hollow portion). It can also be suitably used for a front working machine having a non-lifting arm.

  In order to solve the above-described problem, the present invention provides a front work machine that is rotatably attached to a work vehicle, and the front work machine includes a lift arm having a work attachment attached to a tip. A hydraulic actuator for rotating the lift arm relative to the work vehicle; and a hydraulic pipe for supplying hydraulic oil to the hydraulic actuator, wherein the lift arm and the hydraulic pipe are detachable from the work vehicle. Provide a front working machine.

  According to this configuration, the lift arm and the hydraulic piping can be handled as a set of assemblies. This eliminates the need for fixing and detaching the hydraulic piping from the lift arm each time the front work machine is attached or detached as in the prior art. Accordingly, the piping work, and hence the attaching / detaching work of the front work machine with respect to the work vehicle can be simplified.

  An agricultural tractor can be mentioned as a work vehicle which mounts the front work machine concerning the present invention described above.

  As described above, according to the front working machine of the present invention, it is possible to simplify the piping work of the hydraulic piping, and consequently the attaching / detaching work to the work vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a left side view of a front side of a work vehicle equipped with a front work machine according to an embodiment of the present invention. It is the same front view. It is the same top view. (A) The figure is the A section enlarged arrow view in FIG. 1, (b) The figure is the B section enlarged arrow view in FIG. (A) The figure is the partial front view which shows the state just before attaching the front work machine which relates to this invention to the work vehicle, (b) the figure which (a) figure saw from X1 direction, (c) figure Is a perspective view showing the second pin, (d) is an enlarged view of portion C in FIG. 1, (e) is a view of (d) from the X2 direction. It is a front side left view of the working vehicle which mounts the front working machine which concerns on other embodiment of this invention. (A) A figure is the D section expanded arrow figure of FIG. 6, (b) A figure is a top view of (a) figure. It is a side view which shows an example of a well-known front work machine.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. FIG. 1 is a left side view showing a state in which a front work machine 10 according to an embodiment of the present invention is mounted on an agricultural tractor 1 (hereinafter simply referred to as “tractor 1”) as a work vehicle. FIG. 2 is a front view of FIG. 2, and FIG. 3 is a top view of the same. In the following, the terms “width direction”, “vertical direction”, and “front-rear direction” may be used to indicate directionality, which are respectively the width direction of the tractor 1, the vertical direction of the tractor 1, And the front-back direction of the tractor 1 is meant.

  The tractor 1 is provided with a hydraulic circuit including a driver's seat, an engine, and a hydraulic pump driven by the engine on the vehicle body, and hydraulic piping extends from the hydraulic circuit (all are not shown). A support frame 2 for supporting the front work machine 10 is fixedly provided at the front portion of the tractor 1. The support frame 2 is spaced apart in the width direction and extends along the front-rear direction, the front stays 3, 3, the front holder 4 extending upward from the front end of each front stay 3, 3, and the front stays 3, 3 The main parts are brackets 5 and 5 as rotation support portions provided at the rear end portion. The front holder 4 includes a pair of left and right column portions 4a and 4a extending in the vertical direction, and a width direction portion 4b extending in the width direction between the upper ends of both the column portions 4a and 4a.

  The front work machine 10 includes a pair of left and right lift arms 11, a work attachment 12 attached to the tip of the lift arm 11, and a lift cylinder 13 as a hydraulic actuator that rotates the lift arm 11 relative to the tractor 1. Is attached to the support frame 2 of the tractor 1 in a detachable manner. The work attachment 12 in the illustrated example is called a blade (or a grader), extends along the width direction, and mainly performs leveling work and snow removal work. The front working machine 10 including this type of work attachment 12 is also referred to as a front dozer.

  The work attachment 12 is attached to the tip of the lift arm 11 via the connecting member 14. The connecting member 14 is provided with a stand mechanism 15 for holding the front work machine 10 in a self-standing (standing) state when the front work machine 10 is detached from the tractor 1. The base mechanism of the stand mechanism 15 is fixed to the connecting member 14 so as to be rotatable with respect to the lift arm 11, and can be accommodated along the longitudinal direction of the lift arm 11 when the front work machine 10 is in use. It has become.

  As shown in FIGS. 1 and 2, one lift cylinder 13 is provided along the vertical direction at a substantially central portion in the width direction of the tractor 1, and its upper end (the tip of the cylinder rod 13a) is the front. While being fixed to the width direction part 4b of the holder 4, the lower end part is fixed to the back side of the working attachment 12. Although not shown in detail, the oil chamber of the lift cylinder 13 is connected to the tip of a hydraulic pipe extending from a hydraulic circuit provided on the vehicle body of the tractor 1. The lift cylinders 13 can be provided at a plurality of locations in the width direction of the tractor 1.

  The lift arm 11 is disposed between the vehicle body of the tractor 1 and the front wheel 6, and in order to avoid interference with an axle or the like that supports the front wheel 6, the lift arm 11 has an arcuate shape whose middle portion in the longitudinal direction is curved upward. . The lift arm 11 is formed of a cylindrical body, more specifically, a cylindrical body having an oval cross section in which a long axis is arranged in the vertical direction (see dotted lines in FIGS. 4A and 4B). The cross-sectional shape of the lift arm 11 in the present embodiment is a so-called rounded rectangle formed by two parallel lines of equal length and two arcs. The lift arm 11 having such a configuration is obtained by, for example, pressing and bending a single round pipe made of SS400 (rolled steel) or bending a single oval pipe. Can do.

  4 (a) and 4 (b), the rear end side and the front end side opening of the lift arm 11 having a cylindrical shape are closed by lid members 16 and 17, respectively. Thereby, it is possible to prevent as much as possible dirt and snow from entering the cylindrical lift arm 11 with the traveling operation of the tractor 1. However, as will be described later, either one of the lift arms 11, 11 (left side in the present embodiment; lower side in FIG. 3) is provided on the vehicle body of the tractor 1. A hydraulic pipe (not shown) extending from the hydraulic circuit is inserted. Therefore, the cover members 16 and 17 that close the opening of the left lift arm 11 are provided with holes 16a and 17a, respectively, through which hydraulic piping can be passed. In this embodiment, the hole 16a of the lid member 16 fixed to the rear end side is a square hole of 50 mm length × 30 mm width, and the hole 17a of the lid member 17 fixed to the tip side is 30 mm × 40 mm width. It is said to be a square hole. Of course, the shape and size of the holes 16a and 17a are not particularly limited as long as the hydraulic piping can be passed therethrough, and the holes 16a and 17a are lid members for closing the opening portions at both ends of the right lift arm 11. 16 and 17 may be provided.

  The lift arm 11 is rotatably attached to the tractor 1 (strictly, the bracket 5 as a rotation support portion) via a connection portion 18 provided at the rear end thereof. When the cylinder rod 13a of the lift cylinder 13 is shortened, the lift arm 11 and the work attachment 12 are integrally rotated upward with the connecting portion 18 and the connecting portion of the bracket 5 as a fulcrum. On the other hand, when the cylinder rod 13a is extended, the lift arm 11 and the work attachment 12 are integrally rotated downward. During the rotation of the lift arm 11, the posture of the lift cylinder 13 does not change.

  Next, the attachment structure of the front work machine 10 according to this embodiment to the tractor 1 will be described focusing on the attachment structure of the lift arm 11 to the bracket 5 and the piping structure of the hydraulic piping.

  As shown in FIGS. 5A and 5D, the lift arm 11 is attached to the bracket 5 after the connecting portion 18 provided at the rear end of the lift arm 11 and the bracket 5 are connected by the connecting pin 21. Then, the retaining pin 22 is inserted into the connecting pin 21 to prevent the connecting pin 21 from coming off. In more detail, it is as follows.

  As shown in FIG. 5 (a), the bracket 5 has a pair of side plates 5a and 5b that are spaced apart from each other in the width direction. Is provided. The bracket 5 has a first through hole 5d extending in the width direction through the center of the thick part 5c, and a direction passing through the thick part 5c in the vertical direction and orthogonal to the extending direction of the first through hole 5e. A second through hole 5f extending in the direction is provided. On the other hand, at the lower end of the connecting portion 18 of the lift arm 11, a bearing portion 18a having a through hole 18a1 extending in the width direction is provided. And after arrange | positioning the bearing part 18a of the lift arm 11 between the side plates 5a and 5b of the bracket 5 so that the through-hole 18a1 may become concentric with the 1st through-hole 5d of the bracket 5, it is set to each through-hole 5d and 18a1. The connecting pin 21 is inserted. Accordingly, the lift arm 11 is connected to the bracket 5 and the lift arm 11 can be rotated with respect to the bracket 5.

  Here, the connecting pin 21 has a through hole 21a that penetrates the pin portion in the radial direction and a handle portion 21b that extends outward in the radial direction of the pin portion. The through hole 21 a is arranged concentrically with the second through hole 5 d of the bracket 5 when the connecting pin 21 is inserted into the first through hole 5 d of the bracket 5 and the through hole 18 a 1 of the bearing portion 18 a of the lift arm 11. Thus, the connecting pin 21 is formed at a predetermined position in the insertion direction. The handle portion 21b is provided behind the through hole 21a in the insertion direction so as to extend along the extending direction of the through hole 21a (see FIG. 5B).

  The connecting pin 21 is inserted into the bracket 5 and the lift arm 11 as described above, and the second through hole 5e provided in the bracket 5 and the through hole 21a of the connecting pin 21 are inserted as shown in FIG. After matching the directivity, the retaining pin 22 is inserted into the through holes 5e and 21a. Thereby, the movement of the connecting pin 21 is restricted, and the connecting pin 21 is prevented from coming off from the bracket 5 (see FIG. 5D). Since the connecting pin 21 is provided with a handle portion 21b extending along the extending direction of the through hole 21a, as shown in FIG. 5B, the handle portion 21b is formed along the vertical direction. The alignment of the direction of both through holes 5e and 21a can be completed only by arranging them.

  As shown in FIG. 5 (c), the retaining pin 22 used in the present embodiment has a substantially semicircular handle portion 22c that can be rotated on the head portion 22b, and the handle portion 22c includes: When this is rotated in the direction approaching the pin portion 22a, a slit portion 22c1 having a width that allows the pin portion 22a to pass therethrough is provided. Accordingly, when the retaining pin 22 is inserted into the through holes 5e and 21a, the grip portion 22c is not interfered with the thick portion 5c of the bracket 5, while after the retaining pin 22 is completely inserted, The handle 22c is rotated so that the tip of the handle 22c is disposed at a position that is approximately 180 ° out of phase with the head 22a (see FIG. 5E). Thereby, the grip portion 22c of the retaining pin 22 engages with the thick portion 5c of the bracket 5, so that the retaining pin 22 itself is prevented from being detached.

  As described above, the attachment of the lift arm 11 to the bracket 5 is completed. If the attachment structure shown above is employ | adopted, the attachment operation | work of the lift arm 11 with respect to the bracket 5 of the tractor 1 can be performed simply, without using a tool etc. On the other hand, when the lift arm 11 is detached from the bracket 5, the handle portion 22 c of the retaining pin 22 is rotated to release the engaged state between the handle portion 22 c and the thick portion 5 c of the bracket 5, and then come off. The stop pin 22 may be extracted and the connecting pin 21 may be extracted. Since the grip portions 21b and 22c provided on these pins 21 and 22 can be gripped, the pins 21 and 22 can be easily extracted without using a tool or the like.

  Although not shown in detail, the mounting structure of the cylinder rod 13a of the lift cylinder 13 to the width direction portion 4b of the front holder 4 is the same as the mounting structure of the lift arm 11 to the bracket 5.

  As described above, after the front work machine 10 is mounted on the tractor 1, the hydraulic work is performed so that the front work machine 10 can be used. The piping operation of the hydraulic piping in the present embodiment is performed by fixing the hydraulic piping to the hole 16 a of the lid member 16 fixed to the base end portion of the left lift arm 11 → the left lift arm 11 → the distal end portion of the left lift arm 11. After the holes 17a of the lid member 17 are inserted in this order, the hydraulic piping is disposed along the back surface of the work attachment 12, and the tip of the hydraulic piping is connected to the oil chamber of the lift cylinder 13 to complete.

  As described above, in the present invention, the lift arm 11 is formed in a cylindrical shape, and the hydraulic piping can be inserted into the lift arm 11. Therefore, the hydraulic piping extending from the tractor 1 extends along the lift arm 11. The portion can be inserted into the lift arm 11. In this case, since the operation range of the hydraulic piping can be regulated by the inner wall surface of the lift arm 11, at least a portion extending along the lift arm 11 in the hydraulic piping is provided with a fixing tool such as a binding band as in the conventional case. It is not necessary to use and fix to the lift arm 11. Therefore, the piping work of hydraulic piping can be simplified.

  Further, if hydraulic piping is inserted into the lift arm 11, even if dirt or the like is scattered or accumulated on the lift arm 11 as the tractor 1 travels, at least the lift arm 11 is inserted in the hydraulic piping. The portion is not subjected to an external load due to accumulated earth and sand. Thereby, the possibility that the hydraulic piping is deteriorated or damaged can be reduced, and the labor required for the maintenance of the hydraulic piping can be reduced. In particular, as in the present embodiment, if the lift arm 11 is formed in an arc shape whose middle portion in the longitudinal direction is curved upward, for example, the lift arm 11 passes under the axle (a member that supports the front wheel 6). As compared with the above, it is possible to reduce the possibility that earth and sand are scattered and accumulated on the lift arm 11 as the tractor 1 travels. Therefore, the possibility of damage to the hydraulic piping can be reduced more effectively.

  However, if the cylindrical lift arm 11 is formed of a plurality of cylindrical bodies connected by welding or the like, welding marks are formed in a protruding shape inside the lift arm 11. This may hinder the insertion work of the hydraulic piping, and may damage the hydraulic piping at the time of insertion. On the other hand, if the lift arm 11 is obtained from a single pipe material as described above, a projection-like weld mark is not formed, so that the above-described problems are effectively prevented. be able to.

  Further, since the cylindrical lift arm 11 is formed in a cross-sectional oval shape in which the long axis is arranged in the vertical direction, it is possible to increase the rigidity against the bending load and improve the reliability of the front work machine 10. it can.

  FIG. 6 is a left side view of the front portion of the tractor 1 to which the front work machine 10 according to another embodiment of the present invention is mounted. The front work machine 10 shown in the figure differs from the above-described embodiment in that the lift cylinder 13 (hydraulic actuator) is attached to the tractor 1 in a different manner.

  Specifically, the lift cylinder 13 (the main body) is fixed to the lift arms 11 and 11 via a fixing member 19 extending in the width direction as shown in FIGS. The tip of the rod 13a is fixed to a fixed shaft 20 (see FIG. 6) extending in the width direction in front of the tractor 1. As a result, the support frame 2 of the tractor 1 omits the front holder 4. When such a configuration is adopted, the lift arm 11 and the work attachment 12 are rotated with respect to the tractor 1 integrally with the lift cylinder 13 with the tip of the cylinder rod 13a as a support point in accordance with the extension and shortening operations of the cylinder rod 13a. To do. More specifically, when the cylinder rod 13a extends, the lift arm 11 and the work attachment 12 rotate upward as shown by a two-dot chain line in FIG. 6, while when the cylinder rod 13a shortens, the lift arm 11 and The work attachment 12 rotates downward (returns to the origin).

  Since other configurations are substantially the same as those in the above-described embodiment, detailed description thereof is omitted.

  Although the case where the lift arm 11 is configured by a cylindrical body having a rounded rounded rectangular shape has been described above, the lift arm 11 is configured by a cylindrical body having another oval cross section such as an oval shape or an oval shape. It is also possible (not shown).

  Further, the mounting structure of the front work machine 10 described in detail with reference to FIG. 5 is not only used when the cylindrical lift arm 11 is mounted on the bracket 5 of the tractor 1 (the rotation support part of the work vehicle). The plate-like lift arm 11 that does not have a hollow portion can also be suitably used when attached to the bracket 5 of the tractor 1.

  In the above, the front working machine is configured to supply hydraulic oil to the lift cylinder 13 for rotating the lift arm 11 and the work attachment 12 with respect to the tractor 1 through the hydraulic pipe extending from the main body of the tractor 1. In the present invention, the front work machine 10 in which the lift arm 11 and the hydraulic piping are detachable from the tractor 1, in other words, the lift cylinder 13 to which the hydraulic piping is connected in advance is provided. A front work machine 10 is also provided. With the front working machine 10 having such a configuration, the lift arm 11 and the hydraulic piping can be handled as a set of assemblies. Therefore, it is not necessary to fix and remove the hydraulic piping from the lift arm 11 every time the front work machine 10 is attached / detached as in the prior art. Accordingly, the piping work, and thus the attaching / detaching work of the front work machine 10 to the tractor 1 can be simplified.

  When such a configuration is adopted, the lift arm 11 may be configured by a cylindrical body having a hollow portion as described above, or may be configured by a plate-shaped body having no hollow portion. Even in the front working machine 10 having such a configuration, the structure for attaching the lift arm 11 to the tractor 1 (the rotation support portion thereof) described with reference to FIG. 5 can be adopted.

1 Agricultural tractor (work vehicle)
2 Support frame 5 Bracket (Rotating support part)
10 Front working machine 11 Lift arm 12 Work attachment 13 Lift cylinder (hydraulic actuator)
15 Stand mechanism 16, 17 Lid member 21 Connecting pin 22 Retaining pin

Claims (4)

A lift arm having a work attachment attached to the tip thereof and a hydraulic actuator for rotating the lift arm up and down with respect to the agricultural tractor are connected to a hydraulic pipe extending from the agricultural tractor. In front work machine,
The lift arm is a cylindrical body formed by performing plastic working on a single metal pipe, front attachment, characterized in that the hydraulic pipe can be inserted. 2. The front work machine according to claim 1, wherein the lift arm has an oval cross section in which a long axis is disposed along a vertical direction of the agricultural tractor . The front work machine according to claim 1 or 2, wherein the lift arm is detachably attached to a rotation support portion provided on the agricultural tractor .   4. The lift arm is detachably attached to the rotation support portion by a connection pin for connecting the lift arm to the rotation support portion and a retaining pin for preventing the connection pin from coming off. The listed front work machine.

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