Work vehicle

Abstract

To provide a connection mechanism that connects pipes whose ends in a longitudinal direction are opposed to each other, and that facilitate avoiding the center of gravity of an entire ROPS structure from rising or avoiding inviting the complexity of the structure.SOLUTION: A connection mechanism 5 that connects ends of a first pipe 11 and second pipe 12 includes: a tabular first joint member 51 disposed at an end of the first pipe 11; a tabular second joint member 52 disposed at an end of the second pipe 12; and a coupling bolt 53 that couples the first joint member 51 and second joint member 52. The first joint member 51 and second joint member 52 are provided with coupling holes 51a and 52a, into which coupling bolts 53 can be inserted, at positions where the first joint member and second joint member are exposed from the first pipe 11 and second pipe 12 respectively. The first joint member 51 and second joint member 52 are coupled to each other with the coupling bolts 53 inserted into the coupling holes 51a and 52a with the tabular parts of the first joint member and second joint member superposed on each other.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a work vehicle having a rope equipped with a plurality of pipes and a connection mechanism that connects the longitudinal ends of the pipes together. [Background technology]

[0002] Patent Document 1 discloses a work vehicle equipped with a rope. In this structure, a pipe member is bent to form a rope that is U-shaped in side view. The rope of this work vehicle is connected at its lower end to a cross member fixed to the driver's seat frame of the vehicle body via a connecting member made of a casting (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-59696 Summary of the Invention [Problem to be solved by the invention]

[0004] The technique described in Patent Document 1 is useful in that the connecting member made of a cast has fittings and threaded portions for the pipe members constituting the ROPS, allowing for strong fastening and fixing. However, the need for expensive molds to manufacture the castings poses a cost problem. Furthermore, when adopting a ROPS with a long longitudinal structure to accommodate a work vehicle with multiple rows of seats, it may be necessary to connect the pipe members in the longitudinal direction of the ROPS or to connect the frame members that support it in the lateral and vertical directions. In this case, the heavy cast connecting member tends to be located at the top of the ROPS, raising the center of gravity of the ROPS and the center of gravity of the vehicle. Furthermore, to enable ROPS to be connected in multiple directions other than the longitudinal direction, such as the lateral and vertical directions, the structure of the connecting member itself becomes complex, which requires a larger and heavier mold. Furthermore, there is room for improvement in that the design becomes more complex, taking into account factors such as the punching direction, which increases the cost.

[0005] The present invention aims to provide a connection mechanism for connecting pipes whose longitudinal ends face each other, which can easily avoid an increase in weight or a complicated structure at the connection point. [Means for solving the problem]

[0006] The work vehicle of the present invention comprises: The first pipe, A second pipe; a connecting mechanism for connecting the longitudinal ends of the first pipe and the second pipe to each other; The connection mechanism includes a plate-shaped first joint member provided at an end of the first pipe so as to protrude from the end of the first pipe toward the second pipe, a plate-shaped second joint member provided at the end of the second pipe so as to protrude from the end of the second pipe toward the first pipe, and a connecting bolt that connects the first joint member and the second joint member, Each of the first joint member and the second joint member is provided with a connecting hole through which the connecting bolt can be inserted at a portion exposed from the first pipe and the second pipe, The first joint member and the second joint member are connected by the connecting bolt inserted into the connecting hole in a state in which the plate surface portions of the first joint member and the second joint member are overlapped. 、 The rope includes a lower pipe at a lower portion of the rope, the first pipe is connected to the front upper end of the lower pipe; The second pipe is connected to the rear upper end of the lower pipe. It has the following characteristics:

[0007] According to the present invention, the connection mechanism includes a plate-shaped first joint member protruding from the end of the first pipe, a plate-shaped second joint member protruding from the end of the second pipe toward the first pipe, and a connecting bolt. The first joint member and the second joint member are connected by bolts with their plate surfaces overlapping at the locations exposed from the first pipe and the second pipe. Since the connection mechanism is primarily constructed from plate material, it can be manufactured at lower cost and lighter than castings that require molds. This avoids situations where the weight of the connection mechanism increases at the point where the upper part of the ROP is connected, raising the center of gravity of the entire ROP. Furthermore, because it can be constructed using a simple connecting structure of plate material and bolts, it has the advantage of being easy to simplify the structure and assemble and disassemble.

[0008] In one preferred embodiment of the present invention, the connection mechanism includes a first mounting base plate fixed to an end of the first pipe, the first mounting base plate having a surface intersecting the longitudinal direction, and a second mounting base plate fixed to an end of the second pipe, the second mounting base plate having a surface intersecting the longitudinal direction, The first joint member is attached to the first pipe via the first mounting seat plate, and the second joint member is attached to the second pipe via the second mounting seat plate.

[0009] According to this means, the first coupling member and the second coupling member are attached to the first pipe and the second pipe via a first mounting base plate having a surface that intersects with the end of the first pipe, and a second mounting base plate having a surface that intersects with the end of the second pipe. Therefore, the cross-sectional shapes of the first coupling member and the second coupling member do not need to match the cross-sectional shapes of the first pipe and the second pipe, and can be freely formed into cross-sectional shapes that are completely unrelated to the cross-sectional shapes of the first pipe and the second pipe. This allows the cross-sectional shapes of the first coupling member and the second coupling member to be formed into any shape while taking into consideration a structure that makes them easy to connect to each other.

[0010] In one preferred embodiment of the present invention, The rope is provided with a cross frame connected to the first pipe and the second pipe in a direction crossing the first pipe and the second pipe, The first pipe and the second pipe are provided at an interval from each other in the longitudinal direction, an end of a connection target portion of the cross frame is disposed within the interval width in the longitudinal direction; The connection mechanism includes a branch joint portion provided in each of the first joint member and the second joint member, the branch joint portion extending in a direction in which the cross frame is located, The cross frame is connected to the branch joint.

[0011] According to this means, the branch joint portions extending from the first joint member and the second joint member can be connected to the cross frame that is connected in a direction crossing the first pipe and the second pipe. Therefore, the first joint member and the second joint member can be utilized not only as a means for simply connecting the first pipe and the second pipe, but also as a means for connecting to the cross frame by utilizing the branch joint portion.

[0012] In one preferred embodiment of the present invention, the cross frame is a vertical support frame connected to the first pipe and the second pipe so as to cross the first pipe and the second pipe in a direction along the up-down direction.

[0013] According to this means, when setting up a vertical support frame that supports the middle of the long part of the rope, the connection mechanism that connects the first pipe and the second pipe can also be used as a connection means when setting up the vertical support frame.

[0014] In one preferred embodiment of the present invention, the cross frame is a horizontal frame connected to the first pipe and the second pipe so as to cross the first pipe and the second pipe in a direction along the horizontal direction.

[0015] According to this means, when a cross frame is installed to support the middle of the long part of the rope, the connection mechanism that connects the first pipe and the second pipe can also be used as a connection means when installing the cross frame.

[0016] In one preferred embodiment of the present invention, The vertical support frame is made of square pipe material with a rectangular cross section, a cylindrical boss formed of a cylindrical member that penetrates the square pipe material in the radial direction; a fixing bolt inserted into the cylindrical boss, The branch joint portion is configured to be fixed by being brought into contact with the end face of the cylindrical boss as the fixing bolt is tightened.

[0017] With this method, the tightening force of the fixing bolt is received by the end face of the cylindrical boss and does not act on the square pipe material, so that the branch joint section and the vertical support frame can be connected strongly by tightening the fixing bolt.

[0018] In one preferred embodiment of the present invention, The cross-bridge frame is formed in a downwardly open channel shape having an upward surface along a horizontal direction and hanging side surfaces bent downward from both sides of the upward surface, The branch joint portions of the first joint member and the second joint member are provided to overlap on an upper side of the upward surface, a bolt insertion hole is formed in the upward surface and in each of the branch joint portions of the first joint member and the second joint member; The upward surface, the first joint member, and the second joint member can be connected and fixed together by an upper connecting bolt inserted into the bolt insertion hole.

[0019] According to this means, the first joint member, the second joint member, and the upward surface of the cross frame can be fastened and fixed together by the upper connecting bolt.

[0020] In one preferred embodiment of the present invention, the cross frame includes a vertical support frame connected to the first pipe and the second pipe so as to cross in a direction along the up-down direction, and a horizontal frame connected to the first pipe and the second pipe so as to cross in a direction along the horizontal direction, The vertical support frame is made of square pipe material with a rectangular cross section, a cylindrical boss formed of a cylindrical member that penetrates the square pipe material in the radial direction; a fixing bolt inserted into the cylindrical boss, The branch joint portion is configured to be fixed by being brought into contact with the end surface of the cylindrical boss as the fixing bolt is tightened, The horizontal frame is formed in a downwardly open channel shape having an upward surface along a horizontal direction and hanging side surfaces bent downward from both sides of the upward surface, The branch joint portions of the first joint member and the second joint member are provided to overlap on an upper side of the upward surface, a bolt insertion hole is formed in the upward surface and in each of the branch joint portions of the first joint member and the second joint member; an upper connecting bolt inserted into the bolt insertion hole can connect and fix three components: the upward surface, the first joint member, and the second joint member; The horizontal frame has a hanging end face bent downward from the upward surface at the end closer to the vertical support frame than the bolt insertion hole, and the hanging end face has a connection target surface portion facing the end face opposite the end face of the tubular boss, and the fixing bolt inserted into the tubular boss is inserted into the connecting hole formed in the connection target surface portion, so that the hanging end face is abutted against the opposite end face of the tubular boss as the fixing bolt is tightened.

[0021] According to this means, the vertical support frame and the horizontal frame are connected to the connection point between the first pipe and the second pipe, so that the long rope can be firmly supported in the vertical and horizontal directions at the middle position in the fore-and-aft direction. Furthermore, the hanging end faces at the ends of the horizontal frame are also effectively used as a means of connecting the vertical support frame and the horizontal frame, so that a ROPS with a simple yet strong structure can be obtained.

[0022] In one preferred embodiment of the present invention, the first pipe and the second pipe are non-circular pipes having a cross-sectional shape.

[0023] This method provides a suitable connection mechanism that is easy to apply to locations where the first pipe and second pipe are made of irregular pipes, such as when an irregular pipe with a seal receiving surface is used in an LOP that has front or rear doors equipped with seals. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. [Figure 2] FIG. 1 is a perspective view showing the entire ROPS. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 5. DETAILED DESCRIPTION OF THE INVENTION

[0025] An example of an embodiment of a work vehicle according to the present invention will be described below with reference to the drawings. Unless otherwise specified, the front-rear direction and left-right direction in the description of this embodiment are described as follows: In other words, when a multipurpose work vehicle, which is an example of a work vehicle to which the present invention is applied, is traveling, the forward traveling direction (see arrow F in FIG. 2) is "forward," the backward traveling direction (see arrow B in FIG. 2) is "rear," the direction corresponding to the right side based on the forward posture in the front-rear direction (see arrow R in FIG. 2) is "right," and similarly the direction corresponding to the left side (see arrow L in FIG. 2) is "left." Furthermore, arrow U in the figures indicates the "up" direction, and arrow D indicates the "down" direction.

[0026] [Overall structure] FIG. 1 shows the entirety of a multipurpose work vehicle, which is an example of a work vehicle according to the present invention. As shown in Figure 1, the multipurpose work vehicle has a running body 1 in which the front of the body frame 2 is supported by steerable left and right front wheels 1F, 1F, and the rear of the body frame 2 is supported by non-steerable left and right rear wheels 1R, 1R. At the rear of the body frame 2, the body frame 2 comprises an upper frame 21 on which the loading platform 20 is mounted, and a lower frame 22 below which supports a drive unit 23 such as an engine. Power from the drive unit 23 is transmitted to the rear wheels 1R, 1R and is also branched and transmitted to the front wheels 1F, 1F, allowing the traveling vehicle body 1 to be configured as a four-wheel drive vehicle. The loading platform 20 is configured to be able to swing in a dump manner with its rear end as a swing fulcrum.

[0027] A passenger section 3 equipped with a rope 4 is provided on the body frame 2 behind a front hood 24 and in front of the luggage bed 20. The passenger section 3 is divided into a front compartment 3F and a rear compartment 3R, with a steering wheel 30 and a front seat 31 provided in the front compartment 3F, and a rear seat 32 provided in the rear compartment 3R. The passenger section 3 equipped with the ROPS 4 has a windshield 33 at the front and a rear glass 34 at the rear, with a roof 35 located above the ROPS 4. Right and left front doors 36 are provided on the right and left sides at the front of the ROPS 4, and right and left rear doors 37 are provided on the right and left sides at the rear of the ROPS 4.

[0028] [ROPS] As shown in Figures 1 and 2, the ROPS 4 is provided with right and left lower pipes 10 that are channel-shaped when viewed from the side, right and left upper front pipes 11 (corresponding to the first pipes) that are angle-shaped when viewed from the side, right and left upper rear pipes 12 (corresponding to the second pipes) that are angle-shaped when viewed from the side, right and left vertical support frames 13, 13 (corresponding to the cross frames), and a cross frame 14 (corresponding to the cross frame). The front upper end of the lower pipe 10 and the lower end of the upper front pipe 11 are connected via upper and lower joint members 17. The front cross frame 15 is connected across the right and left upper and left joint members 17, and a flat connecting plate 19F is connected across the right and left upper front pipes 11.

[0029] The rear upper end of the lower pipe 10 and the lower end of the upper rear pipe 12 are connected via a rear upper and lower joint member 18. A flat connecting plate 19R is connected to the rear horizontal frame 16 across the right and left upper rear pipes 12. The rear end of the upper front pipe 11 and the front end of the upper rear pipe 12 are arranged so that the rear end and the front end, which are longitudinal ends, face each other, and are connected via a connection mechanism 5, which will be described later.

[0030] The right and left vertical support frames 13, 13 are provided along the vertical direction, spanning a location corresponding to the middle in the fore-and-aft direction of the lower pipe 10 and a connection location between the rear end of the upper front pipe 11 and the front end of the upper rear pipe 12. The lower ends of these vertical support frames 13, 13 are connected by bolts to a support base member (not shown) of the front seat 31 that stands upright from the body frame 2, and the upper ends are connected to the upper front pipe 11 and the upper rear pipe 12 via a connection mechanism 5, which will be described later.

[0031] The lateral frame 14 is connected in the left-right direction across the connection point between the rear end of the right upper front pipe 11 and the front end of the right upper rear pipe 12, and the connection point between the rear end of the left upper front pipe 11 and the front end of the left upper rear pipe 12. In other words, the rear end of the upper front pipe 11 and the front end of the upper rear pipe 12 are connected via a connection mechanism 5, which will be described later, and both ends of this lateral frame 14 are also connected to the upper front pipe 11 and the upper rear pipe 12 via the connection mechanism 5, which will be described later.

[0032] The lower pipe 10, upper front pipe 11, and upper rear pipe 12 that make up the ROPS 4 are made of irregularly shaped pipes with non-circular cross sections. The reason for using irregularly shaped pipes in this way is to form a flat or concave surface on the seal receiving surface on the ROPS 4 side that abuts against the rubber seal members 36a, 37a attached to the periphery of the front door 36 and rear door 37, making it easier to prevent rainwater from entering, etc.

[0033] As shown in Figs. 3 and 4, the right and left vertical support frames 13, 13 are made of square pipe material with a rectangular cross section that is wider in the front-to-rear direction. As shown in Figures 6 and 7, the upper part of each vertical support frame 13, which is the end of the connection target point, is positioned so as to be located at a position corresponding to the space between the rear end of the upper front pipe 11 and the front end of the right upper rear pipe 12 in the front-to-back direction, and also in the left-to-right direction, at a position corresponding to the width between the rear end of the upper front pipe 11 and the front end of the right upper rear pipe 12.

[0034] Two cylindrical bosses 13a, each made of a cylindrical member that penetrates the square pipe material in the radial direction (left-right direction), are welded to the top and bottom of the upper part of each vertical support frame 13. The cylindrical bosses 13a have an inner diameter that allows the insertion of fixing bolts 13b of the connection mechanism 5, which will be described later, and each vertical support frame 13 can be connected to the connection mechanism 5 by tightening the fixing bolts 13b inserted therein. Of both end faces 13c, 13d of the tube boss 13a, the outer end face 13c in the left-right direction abuts against the branch joint portion 51B of the connection mechanism 5, and the opposite end face 13d abuts against a connection target surface portion 14e of a hanging end face 14d (described later) of the horizontal frame 14. With the branch joint portion 51B and the connection target surface portion 14e abutting against these both end faces 13c, 13d, the fixing bolt 13b is inserted and tightened, thereby connecting the vertical support frame 13, the horizontal frame 14, and the connection mechanism 5.

[0035] As shown in Figures 3, 4, and 7, the horizontal frame 14 has an upward surface 14a extending horizontally and two hanging side surfaces 14b, 14b bent downward from both sides of the upward surface 14a. The upward surface 14a near both lateral ends has a bolt insertion hole 14c through which a connecting bolt 14g for connecting to the connection mechanism 5 (described later) is inserted. A hanging end surface 14d is bent downward from the upward surface 14a at an end closer to the vertical support frame 13 than the bolt insertion hole 14c. This hanging end surface 14d is provided with a connection target surface 14e that faces the opposite end surface 13d of the tubular boss 13a. The connection target surface 14e is located at a height approximately the same as the tubular boss 13a located at the top of the vertical support frame 13 and has a bolt insertion hole 14f through which the fixing bolt 13b can be inserted.

[0036] [Connection mechanism] The connection mechanism 5 that connects the longitudinal ends of the upper front pipe 11 corresponding to the first pipe and the upper rear pipe 12 corresponding to the second pipe is configured as follows. The connection mechanism 5 includes a first mounting seat plate 50A welded to the rear end of the upper front pipe 11 and having a surface that intersects with the longitudinal direction of the upper front pipe 11, a plate-shaped first joint member 51 welded to the surface (rear surface) of the first mounting seat plate 50A opposite to the side welded to the upper front pipe 11, a second mounting seat plate 50B welded to the front end of the upper rear pipe 12 and having a surface that intersects with the longitudinal direction of the upper rear pipe 12, a plate-shaped second joint member 52 welded to the surface (front surface) of the second mounting seat plate 50B opposite to the side welded to the upper rear pipe 12, and a connecting bolt 53 that overlaps and connects the first joint member 51 and the second joint member 52.

[0037] The first joint member 51 is located rearward of a first mounting seat plate 50A that is welded to the rear end of the upper front pipe 11, and the second joint member 52 is located forward of a second mounting seat plate 50B that is welded to the front end of the upper rear pipe 12. In other words, the first joint member 51 and the second joint member 52 are both located in positions that are exposed from the upper front pipe 11 and the upper rear pipe 12, and connecting holes 51a, 52a through which connecting bolts 53 can be inserted are provided in these exposed positions. As a result, rather than connecting the upper front pipe 11 and the upper rear pipe 12 by applying a tightening force from the radial direction to the upper front pipe 11 and the upper rear pipe 12, the plate-shaped first joint member 51 and the second joint member 52 can be tightened in the thickness direction of the plate at the locations exposed from the upper front pipe 11 and the upper rear pipe 12, so that the upper front pipe 11 and the upper rear pipe 12 can be connected without deformation due to tightening.

[0038] 3, 4, and 7, the plate-like first joint part 51 and second joint part 52 have a channel-like cross section, and the connecting holes 51a, 52a are provided at locations corresponding to the bottom of the channel. The channel-like cross section increases the second moment of area of ​​the plate-like first joint part 51 and second joint part 52, making them less susceptible to deformation. Of the connecting holes 51a, 52a, a fixing weld nut 52b is welded and fixed so as to be concentric with the connecting hole 52a of the second joint member 52 that is located on the innermost side. Therefore, the connecting bolt 53 can be tightened from the outside.

[0039] 3 to 7, the first mounting seat plate 50A and the second mounting seat plate 50B have an outer diameter larger than the outer diameters of the upper front pipe 11 and the upper rear pipe 12. By welding and fixing the first mounting seat plate 50A and the second mounting seat plate 50B, which have such large diameters, to the ends of the upper front pipe 11 and the upper rear pipe 12, flange portions are formed at the ends of the upper front pipe 11 and the upper rear pipe 12. This suppresses deformation of the upper front pipe 11 and the upper rear pipe 12 at the connection points, effectively improving strength.

[0040] [Branch joint] As shown in Figures 3 to 7, the connection mechanism 5 has branch joint portions 51A, 51B, and 52A that extend from the first joint member 51 and the second joint member 52 toward the vertical support frame 13 and the horizontal frame 14, which serve as intersecting frames.

[0041] The first joint member 51, which is integrally attached to the upper front pipe 11, has branch joint portions 51A, 51B extending in the direction in which the vertical support frame 13 is located, and these branch joint portions are formed integrally with the plate material that constitutes the first joint member 51. Of the branch joints 51A, 51B, the branch joint 51A extending horizontally toward the cross frame 14 is provided with a hole 51Aa through which a connecting bolt 14g can be inserted. The branch joint portion 51B extends downward in the direction in which the vertical support frame 13 exists, and is provided with a hole 51Ba through which the fixing bolt 13b can be inserted.

[0042] The second joint member 52, which is integrally attached to the upper rear pipe 12, has a branch joint portion 52A that extends horizontally toward the direction in which the cross frame 14 exists, but is not provided in the direction in which the vertical support frame 13 exists. The branch joint portion 52A is provided with a hole 52Aa at the same position as the branch joint portion 51A of the first joint member 51, through which the connecting bolt 14g can be inserted. As a result, the connecting bolt 14g passes through the hole 51Aa and the hole 52Aa, and can fix the branch joint portion 51A of the first joint member 51 and the branch joint portion 52A of the second joint member 52 in a co-fastened state to the upward surface 14a of the cross frame 14. A weld nut 14h that screws onto the connecting bolt 14g is welded and fixed to the back side of the upward surface 14a of the cross frame 14.

[0043] As shown in Figures 4 and 7, a hanging end face 14d provided at the end of the horizontal frame 14 closer to the vertical support frame 13 than the bolt insertion hole 14c, and a connection target surface portion 14e formed at the bottom of the hanging end face 14d enable the horizontal frame 14 and the vertical support frame 13 to be connected to each other. In other words, the hanging end face 14d and the connection target surface portion 14e do not correspond to the branch joint portions 51A, 51B, 52A, but are provided with a bolt insertion hole 14f through which the fixing bolt 13b can be inserted at a position facing the opposite end face 13d of the tubular boss 13a, and therefore are used as a means for connecting the cross frame 14 and the vertical support frame 13 in cooperation with the branch joint portion 51B of the first joint member 51.

[0044] [Another embodiment] Other embodiments will be described below. The following other embodiments may be combined and applied to the above-described embodiment, provided no contradictions arise. The scope of the present invention is not limited to the contents of these embodiments.

[0045] (1) In the above-described embodiment, the work vehicle is driven by the drive unit 23 equipped with an engine, but the present invention is not necessarily limited to this structure. For example, the present invention is not limited to a gasoline engine or a diesel engine, but may also be a hybrid engine, or an engine equipped with a battery and using an electric motor as a drive source. The other configurations may be the same as those of the above-described embodiment.

[0046] (2) In the above-described embodiment, the first joint member 51 and the second joint member 52 are attached to the first pipe and the second pipe via the first mounting seat plate 50A and the second mounting seat plate 50B, respectively. However, the present invention is not necessarily limited to this structure. For example, the first joint member 51 and the second joint member 52 may be attached directly to the first pipe and the second pipe without using the first mounting seat plate 50A and the second mounting seat plate 50B. The other configurations may be the same as those of the above-described embodiment.

[0047] (3) In the above-described embodiment, the first joint member 51 and the second joint member 52 are provided with two branch joint portions, i.e., the branch joint portion 51A and the branch joint portion 51B, as an example. However, the present invention is not necessarily limited to this structure. For example, the structure may include only one of branch joint portion 51A and branch joint portion 51B, or may include three or more branch joint portions, or may include no branch joint portions at all. The other configurations may be the same as those of the above-described embodiment.

[0048] (4) In the above-described embodiment, an example was given of a structure that uses two cross frames, a vertical support frame 13 and a horizontal frame 14, as the cross frame, but this structure is not necessarily limited to this. For example, the structure may have only one of the vertical support frame 13 and the horizontal frame 14, or it may have a structure with three or more cross frames, or it may have no cross frames at all. The other configurations may be the same as those of the above-described embodiment.

[0049] (5) In the above-described embodiment, a structure in which the connection mechanism 5 is provided only at one location in the middle of the ROPS 4 in the fore-and-aft direction is exemplified, but the present invention is not necessarily limited to this structure. For example, a structure in which the connection mechanism 5 is provided at multiple locations in the middle of the ROPS 4 in the fore-and-aft direction may also be used. The other configurations may be the same as those of the above-described embodiment.

[0050] (6) In the above embodiment, the connection mechanism 5 is exemplified as a means for connecting pipes in the ROPS 4, but it may be used as a means for connecting pipes other than the ROPS 4. The other configurations may be the same as those of the above-described embodiment. [Industrial Applicability]

[0051] The present invention is not limited to multipurpose work vehicles, but can also be applied to agricultural work vehicles such as riding mowers and tractors, civil engineering work vehicles such as wheel loaders, forklifts, transport vehicles, etc. [Explanation of symbols]

[0052] 4 Rops Frame 5 Connection mechanism 10 Lower Pipe 11 First Pipe 12 Second Pipe 13 Vertical support frame 13a Tube boss 13b Fixing bolt 13c End face 13d Another end face 13,14 Intersection Frame 14 Horizontal frame 14a Upward facing 14b Hanging Side 14c Bolt insertion hole 14d Hanging end face 14e Connection target surface 14f connection hole 14g Upper connecting bolt 14c, 51Aa, 52Aa Bolt insertion holes 50A First mounting plate 50B Second mounting plate 51 First joint member 51a,52a connection hole 51A, 51B, 52A Branch joint 52 Second joint member 53 Connecting bolt

Claims

1. The first pipe, A second pipe; a connecting mechanism for connecting the longitudinal ends of the first pipe and the second pipe to each other; The connection mechanism includes a plate-shaped first joint member provided at an end of the first pipe so as to protrude from the end of the first pipe toward the second pipe, a plate-shaped second joint member provided at the end of the second pipe so as to protrude from the end of the second pipe toward the first pipe, and a connecting bolt that connects the first joint member and the second joint member, Each of the first joint member and the second joint member is provided with a connecting hole through which the connecting bolt can be inserted at a portion exposed from the first pipe and the second pipe, the first joint member and the second joint member are connected by the connecting bolt inserted into the connecting hole in a state in which plate surface portions of the first joint member and the second joint member are overlapped with each other, The rope includes a lower pipe at a lower portion of the rope, the first pipe is connected to the front upper end of the lower pipe; The second pipe is connected to the rear upper end of the lower pipe.

2. The connection mechanism includes a first mounting base plate fixed to an end of the first pipe, the first mounting base plate having a surface intersecting the longitudinal direction, and a second mounting base plate fixed to an end of the second pipe, the second mounting base plate having a surface intersecting the longitudinal direction, 2. A work vehicle according to claim 1, wherein the first coupling member is attached to the first pipe via the first mounting seat plate, and the second coupling member is attached to the second pipe via the second mounting seat plate.

3. The rope is provided with a cross frame connected to the first pipe and the second pipe in a direction crossing the first pipe and the second pipe, The first pipe and the second pipe are provided at an interval from each other in the longitudinal direction, an end of a connection target portion of the cross frame is disposed within the interval width in the longitudinal direction; The connection mechanism includes a branch joint portion provided in each of the first joint member and the second joint member, the branch joint portion extending in a direction in which the cross frame is located, 2. A work vehicle according to claim 1, wherein said cross frame is connected to said branch joint.

4. 4. The work vehicle according to claim 3, wherein the cross frame is a vertical support frame connected to the first pipe and the second pipe so as to cross the first pipe and the second pipe in a direction along the vertical direction.

5. 4. The work vehicle according to claim 3, wherein the cross frame is a horizontal frame connected to the first pipe and the second pipe so as to cross the first pipe and the second pipe in a direction along the horizontal direction.

6. The vertical support frame is made of square pipe material with a rectangular cross section, a cylindrical boss formed of a cylindrical member that penetrates the square pipe material in the radial direction; a fixing bolt inserted into the cylindrical boss, 5. A work vehicle according to claim 4, wherein the branch joint portion is fixed by being pressed against the end face of the cylindrical boss as the fixing bolt is tightened.

7. The cross-bridge frame is formed in a downwardly open channel shape having an upward surface along a horizontal direction and hanging side surfaces bent downward from both sides of the upward surface, The branch joint portions of the first joint member and the second joint member are provided to overlap on an upper side of the upward surface, a bolt insertion hole is formed in the upward surface and in each of the branch joint portions of the first joint member and the second joint member; 6. A work vehicle according to claim 5, wherein the upward surface, the first joint member, and the second joint member can be connected and fixed together by an upper connecting bolt inserted into the bolt insertion hole.

8. the cross frame includes a vertical support frame connected to the first pipe and the second pipe so as to cross in a direction along the up-down direction, and a horizontal frame connected to the first pipe and the second pipe so as to cross in a direction along the horizontal direction, The vertical support frame is made of square pipe material with a rectangular cross section, a cylindrical boss formed of a cylindrical member that penetrates the square pipe material in the radial direction; a fixing bolt inserted into the cylindrical boss, The branch joint portion is configured to be fixed by being brought into contact with the end surface of the cylindrical boss as the fixing bolt is tightened, The cross-bridge frame is formed in a downwardly open channel shape having an upward surface along a horizontal direction and hanging side surfaces bent downward from both sides of the upward surface, The branch joint portions of the first joint member and the second joint member are provided to overlap on an upper side of the upward surface, a bolt insertion hole is formed in the upward surface and in each of the branch joint portions of the first joint member and the second joint member; an upper connecting bolt inserted into the bolt insertion hole can connect and fix three components: the upward surface, the first joint member, and the second joint member; The work vehicle of claim 3, wherein the horizontal frame has a hanging end surface bent downward from the upward surface at an end closer to the vertical support frame than the bolt insertion hole, the hanging end surface has a connection target surface portion that faces the end surface of the tubular boss opposite the end surface, the fixing bolt that is inserted into the tubular boss is inserted into a connecting hole formed in the connection target surface portion, and the hanging end surface is abutted against the opposite end surface of the tubular boss as the fixing bolt is tightened.

9. The work vehicle according to any one of claims 1 to 8, wherein the first pipe and the second pipe are irregular pipes having a non-circular cross section.

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