Front loader

Abstract

To provide a front loader capable of improving visibility.SOLUTION: The present invention comprises a boom 30 in which an internal space S30 is formed, and a side frame 20 that swingably supports the boom 30 and is formed with a first opening 23 through which a pipe portion 90 for forming a hydraulic oil flow path can be inserted. The first opening 23 is formed on one side surface of the side frame 20 in the left-right direction. A second opening 24 through which the pipe portion 90 can be inserted is formed in the surface of the side frame 20 facing the boom 30.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present invention relates to the technology of a front loader in which a working tool connected to a boom can be operated by hydraulic oil.

Background Art

[0002] Conventionally, the technology of a front loader in which a working tool connected to a boom can be operated by hydraulic oil has been known. For example, it is as described in Patent Document 1.

[0003] The front loader described in Patent Document 1 includes a sub-frame (side frame), a lift arm (boom) swingably supported by the sub-frame, and hydraulic hoses for guiding the hydraulic oil used in various hydraulic cylinders.

[0004] The hydraulic hose described in Patent Document 1 is provided along one side surface on the left and right of the sub-frame and the lift arm in order to guide the hydraulic oil to the hydraulic cylinder provided at the front part of the lift arm. However, in this case, since the hydraulic hose is exposed on the side of the sub-frame or the lift arm, there is a possibility that the hydraulic hose may block the operator's field of vision and the visibility may deteriorate.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] One aspect of the present disclosure has been made in view of the above situation, and the problem to be solved is to provide a front loader capable of improving visibility.

Means for Solving the Problems

[0007] The problem that one aspect of this disclosure aims to solve is as described above, and the means for solving this problem will now be explained.

[0008] That is, in one embodiment of the present disclosure, the system comprises a boom and a side frame that pivotably supports the boom and has a first opening through which a pipe for forming a flow path for hydraulic fluid can be inserted. Furthermore, the boom is capable of being fitted with a posture maintenance mechanism that operates in accordance with the swinging of the boom to maintain the posture of a work tool connected to the boom, and the boom comprises a boom frame formed in a hollow shape having an internal space surrounded by a top surface, side surfaces and a bottom surface, a mounting portion which is at least a part of which is located in the internal space of the boom frame and is for attaching the posture maintenance mechanism, and a guide portion which is at least a part of which is located in the internal space of the boom frame and guides the pipe portion passing through the internal space of the boom frame so as to avoid the mounting portion, and the guide portion is provided in the internal space of the boom frame so as to extend between the mounting portion and the bottom surface of the boom frame. It is. According to one aspect of this disclosure, the pipe section can be placed within the side frame, thereby preventing the pipe section from obstructing the worker's view. Furthermore, by using the guide section to guide the pipe section, it can be easily positioned within the boom.

[0009] In one embodiment of the present disclosure, the first opening is formed on one side of the side frame in the left-right direction. According to one aspect of this disclosure, the pipe section can be introduced into the side frame from the left and right outer sides of the side frame.

[0010] In one embodiment of the present disclosure, a second opening is formed on the side frame facing the boom, through which the pipe portion can be inserted. According to one aspect of this disclosure, a pipe section can be led out from inside the side frame toward the boom.

[0011] In one embodiment of the present disclosure, the boom is formed on the surface facing the side frame and through which the pipe portion can be inserted, and a fourth opening different from the third opening is formed. According to one aspect of this disclosure, visibility can be effectively improved because the pipe portion can effectively suppress obstruction of the worker's view.

[0012] In one embodiment of the present disclosure, the invention further comprises a connecting frame that connects the left and right booms, and a tubular section that is led out from inside the boom through the fourth opening onto the connecting frame, branches on the connecting frame, and is connected to the left and right boom cylinders and the left and right bucket cylinders. According to one aspect of the present disclosure, the branched portions of the pipe parts can be aggregated on the connecting frame, making the assembly and maintenance of the pipe parts easier.

[0013] In one aspect of the present disclosure, it further includes a first cover that covers the pipe parts on the connecting frame. According to one aspect of the present disclosure, the pipe parts on the connecting frame can be hidden by the first cover, improving the aesthetic appearance.

[0014] In one aspect of the present disclosure, an opening is formed in the first cover. According to one aspect of the present disclosure, hydraulic pressure can be utilized through the opening.

[0015] In one aspect of the present disclosure, it further includes a second cover that covers the fourth opening. According to one aspect of the present disclosure, the fourth opening and the pipe parts led out from the fourth opening can be hidden by the second cover, improving the aesthetic appearance.

Effects of the Invention

[0017] According to one aspect of the present disclosure, visibility can be improved.

Brief Description of the Drawings

[0018] [Figure 1] A side view showing the overall configuration of a tractor equipped with a front loader according to an embodiment of the present invention. [Figure 2] A perspective view showing the front loader. [Figure 3] Similarly, a left side view. [Figure 4] Similarly, a right side cross-sectional view. [Figure 5] A front view showing the connecting frame and the pipe parts. [Figure 6] (a) A left side view showing the side frame. (b) A left side view showing the inside of the side frame. [Figure 7] An exploded perspective view of the boom. [Figure 8] Right side cross-sectional view showing the side frame and boom. [Figure 9] Cross-sectional view taken along A1 - A1. [Figure 10] Right side cross-sectional view of the front loader schematically showing the pipe portion. [Figure 11] (a) Front cross-sectional view schematically showing the first pipe portion on the connecting frame. (b) Front cross-sectional view schematically showing the second pipe portion on the connecting frame. [Figure 12] Cross-sectional view taken along A2 - A2. [Figure 13] Rear partial cross-sectional view schematically showing the first pipe portion and the third pipe portion. [Figure 14] Right side cross-sectional view of the front loader schematically showing the third pipe portion. [Figure 15] (a) Front view showing the cover. (b) Cross-sectional view taken along A3 - A3.

Embodiments for Carrying out the Invention

[0019] Hereinafter, the directions indicated by the arrows U, D, F, B, L, and R in the figures will be defined as the upward, downward, forward, rearward, leftward, and rightward directions respectively for the description.

[0020] Hereinafter, the overall configuration of the tractor 1 equipped with the front loader 10 according to an embodiment of the present invention will be described.

[0021] As shown in FIG. 1, the tractor 1 mainly includes a body frame 2, an engine 3, a transmission case 4, front wheels 5, rear wheels 6, a bonnet 7, a cabin 8, a steering wheel 9, and a front loader 10.

[0022] The aircraft frame 2 is a frame-shaped member formed by appropriately combining multiple plate materials. The aircraft frame 2 is formed in a roughly rectangular shape in plan view. The aircraft frame 2 is positioned with its longitudinal direction oriented in the front-rear direction. The engine 3 is fixed to the rear of the aircraft frame 2. The transmission case 4 is fixed to the rear of the engine 3. The front of the aircraft frame 2 is supported by a pair of front wheels 5 via a front axle mechanism (not shown). The rear of the transmission case 4 is supported by a pair of rear wheels 6 via a rear axle mechanism (not shown). The engine 3 is covered by a bonnet 7.

[0023] The power from engine 3 is shifted by a transmission (not shown) housed in a transmission case 4, and then transmitted to the front wheels 5 via the front axle mechanism, and also to the rear wheels 6 via the rear axle mechanism. The power from engine 3 rotates the front wheels 5 and the rear wheels 6, allowing the tractor 1 to move.

[0024] A cabin 8 is located behind the engine 3. Inside the cabin 8 is a living space for the worker. This living space is equipped with a steering wheel 9 for adjusting the steering angle of the front wheels 5, various controls, and a seat for the worker.

[0025] A front loader 10 is mounted on the front of tractor 1. The configuration of the front loader 10 will be briefly explained below with reference to Figures 2 to 5.

[0026] As shown in Figures 2 and 3, the front loader 10 mainly comprises a side frame 20, boom 30, connecting frame 40, bucket 50, stand 60, boom cylinder 70, bucket cylinder 80, pipe section 90, cover 100, and attitude maintenance mechanism 110, etc.

[0027] The side frames 20 support the boom 30, which will be described later, in a swingable manner. The side frames 20 are detachably attached to the body of the tractor 1 (body frame 2 and transmission case 4). The side frames 20 are provided on both the left and right sides of the body. The detailed configuration of the side frames 20 will be described later.

[0028] The boom 30 is pivotably supported by the left and right side frames 20. The boom 30 is positioned to extend from the top of the side frames 20 toward the front and downward. The detailed configuration of the boom 30 will be described later.

[0029] The connecting frame 40 connects the left and right booms 30. The connecting frame 40 is formed in a substantially cylindrical shape with its axis oriented to the left and right. The connecting frame 40 is installed so as to span the left and right booms 30.

[0030] The bucket 50 is formed to open forward. The bucket 50 is pivotably connected to the front end of the boom 30.

[0031] The stand 60 is used to allow the front loader 10, which has been removed from the tractor 1, to stand on its own. One stand 60 is provided on the front underside of each of the left and right booms 30 (a pair). The stand 60 can be switched between a storage position where it is stowed in the boom 30 and a support position where it is on the ground and can support the weight of the front loader 10. The drawing shows the stand 60 in the storage position.

[0032] The boom cylinder 70 is used to pivot the boom 30 relative to the side frame 20. The boom cylinder 70 is pivotably connected to the side frame 20 and the boom 30. A pair of boom cylinders 70 are provided, one on each side.

[0033] The bucket cylinder 80 is used to swing the bucket 50 relative to the boom 30. The bucket cylinder 80 is pivotably connected to the boom 30 and the bucket 50. In this embodiment, the bucket cylinder 80 is pivotably connected to the boom 30 via the second link member 113 of the attitude maintenance mechanism 110, which will be described later. A pair of bucket cylinders 80 are provided, one on the left and one on the right.

[0034] The pipe section 90 shown in Figures 3 to 5 is for forming a flow path for hydraulic fluid. The pipe section 90 connects a hydraulic pump (not shown) driven by engine 3 to a boom cylinder 70, etc. The cover 100 is a component that covers the pipe section 90 (see Figure 2). The detailed configuration of the pipe section 90 and the cover 100 will be described later.

[0035] The posture maintenance mechanism 110 shown in Figures 2 and 3 maintains the posture of the bucket 50 (work tool) by operating in response to the swinging of the boom 30. A pair of posture maintenance mechanisms 110 are provided, one on the left and one on the right. Since the left and right posture maintenance mechanisms 110 have substantially the same configuration, the configuration of the posture maintenance mechanism 110 will be explained below using the left posture maintenance mechanism 110 as an example, and the explanation of the configuration of the right posture maintenance mechanism 110 will be omitted. The posture maintenance mechanism 110 comprises a fixing member 111, a first link member 112, and a second link member 113.

[0036] The fixing member 111 is fixed to the upper part of the side frame 20 and is a member that supports the rear part of the first link member 112.

[0037] The first link member 112 is a member provided between the fixed member 111 and the second link member 113. The first link member 112 is formed in a longitudinal shape that extends substantially in the front-rear direction. The rear end of the first link member 112 is pivotably connected to the fixed member 111. In this way, the first link member 112 can pivot with respect to the fixed member 111 with the left-right direction as the axial direction. The pivot point of the first link member 112 relative to the fixed member 111 is located at a different position from the pivot point of the boom 30 when viewed from the side.

[0038] The second link member 113 is a member that connects to the bucket cylinder 80 and the first link member 112. The second link member 113 is formed in a plate shape with its plate surface oriented approximately left to right. The second link member 113 is formed in a roughly triangular shape when viewed from the side. The lower end of the second link member 113 is pivotably supported on the boom 30 via a roughly cylindrical connecting portion 113a with its axis oriented left to right. The second link member 113 is also connected to the first link member 112 and the bucket cylinder 80 via roughly cylindrical connecting portions 113b and 113c with their axes oriented left to right.

[0039] As described above, the boom 30 of the front loader 10 is swung relative to the side frame 20 in accordance with the extension and retraction of the boom cylinder 70. In this way, the boom 30 is raised and lowered. The first link member 112 and the second link member 113 are swung along with the raising and lowering of the boom 30. The posture maintenance mechanism 110 allows the operator to maintain the posture of the bucket 50 without extending or retracting the bucket cylinder 80 by the swung of these link members 112 and 113.

[0040] The details of the left and right side frames 20 will be described below with reference to Figures 6 and 7. First, the right side frame 20 will be described. The right side frame 20 comprises a side portion 21, a connecting portion 22, a first opening 23, and a second opening 24.

[0041] The side sections 21 form the left and right sides of the side frame 20. The side sections 21 are formed in a plate shape with their surface oriented approximately left to right. The side sections 21 are arranged with a gap between them on the left and right sides.

[0042] The connecting portion 22 connects the left and right side portions 21. The connecting portion 22 is formed in a roughly rectangular ring shape when viewed from the side. The space enclosed by the side portions 21 and the connecting portion 22 becomes the internal space S20 of the side frame 20.

[0043] The first opening 23 is a portion through which the pipe section 90, described later, can be inserted. The first opening 23 is formed to penetrate the left side portion 21 from left to right. Thus, the first opening 23 is formed on the left side of the side frame 20. The first opening 23 communicates with the internal space S20 of the side frame 20. The first opening 23 is formed in a roughly rectangular shape when viewed from the side.

[0044] The second opening 24 shown in Figure 6(b) is a portion through which the pipe section 90 can be inserted. The second opening 24 is formed to penetrate the upper part of the connecting section 22. The second opening 24 is formed above the first opening 23 (towards the boom 30). The second opening 24 communicates with the internal space S20 of the side frame 20.

[0045] The left side frame 20 is configured similarly to the right side frame 20, except that it does not have a first opening 23 and a second opening 24.

[0046] The details of the left and right booms 30 will be described below with reference to Figures 3 and 7 to 9. First, the right boom 30 will be described. As shown in Figures 3 and 7, the boom 30 comprises a boom frame 31, a boss portion 32, a guide portion 33, a closing portion 34, and a side plate 35.

[0047] The boom frame 31 constitutes the main structure of the boom 30. As shown in Figures 8 and 9, the boom frame 31 is formed in a hollow shape having an internal space S30 surrounded by an upper surface 31a, left and right side surfaces 31b, and a bottom surface 31c. The lower ends of the left and right side surfaces 30b are formed to protrude downward from the bottom surface 30a of the boom 30. Thus, a space is formed at the bottom of the boom frame 31, surrounded by the left and right side surfaces 31b and the bottom surface 31c. Hereinafter, this space will be referred to as the "storage space S31". The storage space S31 is formed to extend across both ends in the longitudinal direction of the boom frame 31. As shown in Figures 7 to 9, the boom frame 31 is equipped with a third opening 31d, a through hole 31e, a slit 31f, a fourth opening 31g, and a notch 31h.

[0048] The third opening 31d shown in Figure 8 is a portion through which the pipe section 90 can be inserted. The third opening 31d is formed at the rear end of the bottom surface 31c. The third opening 31d connects the outside of the boom frame 31 with the internal space S30.

[0049] The through-holes 31e shown in Figures 7 and 8 are holes that penetrate the upper surface 31a of the boom frame 31. The through-holes 31e are formed in the middle of the upper surface 31a, from front to back.

[0050] The slit 31f is a horizontally elongated hole that penetrates the boom frame 31 from left to right. The slit 31f is formed on the left and right side surfaces 31b. The slit 31f is formed below the through hole 31e.

[0051] The fourth opening 31g is a portion through which the pipe section 90 can be inserted. The fourth opening 31g is formed to penetrate the left side surface 31b from left to right. The fourth opening 31g is formed in a roughly elliptical shape when viewed from the side. The fourth opening 31g is formed in front of and below (towards the bucket 50) the through hole 31e. The fourth opening 31g is also formed above and behind the connecting frame 40 when viewed from the side.

[0052] The notches 31h shown in Figures 8 and 9 are formed on the left side surface 31b. The notches 31h are formed in a concave shape, as if the end of the side surface 31b has been cut out. The notches 31h are formed on the rear and front of the side surface 31b. In a side view, the rear notch 31h is formed between the third opening 31d and the slit 31f. In a side view, the front notch 31h is formed below the fourth opening 31g and behind the connecting frame 40.

[0053] As described above, the rear end of the boom frame 31 is positioned between the side portions 21 of the side frame 20 and connected to the side portions 21, as shown in Figures 7 and 8. Thus, the boom frame 31 is supported by the side frame 20. The bottom surface 31c of the boom frame 31 faces the connection portion 22 of the side frame 20. In this way, the second opening 24 of this embodiment is formed on the side of the side frame 20 facing the boom 30 (connection portion 22). The third opening 31d is formed on the side of the boom 30 facing the side frame 20 (bottom surface 31c).

[0054] The boss portion 32 is for attaching the second link member 113 of the attitude maintenance mechanism 110. The boss portion 32 is formed in a substantially cylindrical shape with its axis oriented left to right. The length of the boss portion 32 in the axial direction is formed to be longer than the left-right width of the boom frame 31. The boss portion 32 is provided so as to penetrate the left and right side surfaces 31b. In this way, the boss portion 32 is provided so as to traverse the internal space S30 of the boom 30. The boss portion 32 is fixed to the side surfaces 31b of the boom frame 31 by welding or the like.

[0055] A connecting portion 113a, which connects the boom frame 31 and the second link member 113, is inserted through the boss portion 32. In this embodiment, the second link member 113 is supported by the boss portion 32 which crosses the internal space S30 of the boom 30. This allows the second link member 113 to be positioned at a relatively low position. Therefore, it is possible to suppress the second link member 113 from protruding significantly upward from the boom 30 and to prevent the second link member 113 from obstructing the operator's view.

[0056] The guide section 33 is for guiding the pipe section 90, which will be described later. The guide section 33 is formed in the shape of a plate with its plate surface oriented approximately vertically. The left-right width of the guide section 33 is formed to be approximately the same as the left-right width of the boom frame 31. The guide section 33 is fixed to the left and right slits 31f by welding or the like. In this way, the guide section 33 is positioned almost entirely inside the boom 30. The guide section 33 is also provided so as to extend between the boss section 32 and the bottom surface 31c of the boom frame 31. More specifically, the guide section 33 is provided so as to guide the pipe section 90 above the boss section 32, extending rearward from near the top of the boss section 32 and approaching the bottom surface 31c of the boom frame 31, with its rear end positioned near the bottom surface 31c.

[0057] The closing portion 34 is a plate-shaped member that closes the through hole 31e of the boom frame 31. The closing portion 34 is fixed to the boom frame 31 after the boss portion 32 and guide portion 33 are fixed to the boom frame 31. This allows the boss portion 32 and guide portion 33 to be easily welded to the inside of the boom frame 31 through the through hole 31e.

[0058] The side plates 35 are formed in a plate shape with their surface oriented roughly in the left-right direction. The side plates 35 are provided on the left and right sides of the boom frame 31. The left and right side plates 35 are fixed to the front and rear intermediate parts of the boom frame 31.

[0059] The left boom 30 is configured similarly to the right boom 30, except that it does not have a third opening 31d, a slit 31f, a fourth opening 31g, a rear notch 31h, and a guide portion 33.

[0060] The configuration of the pipe section 90 will be described below with reference to Figures 4, 5, and 10 to 14. For convenience, Figures 10 to 14 show the pipe section 90 schematically. The pipe section 90 is formed by appropriately connecting metal pipes and flexible hoses. As shown in Figures 4 and 5, the pipe section 90 comprises a first pipe section 91, a second pipe section 92, and a third pipe section 93.

[0061] The first pipe section 91 connects the hydraulic pump, driven by the engine 3, to the boom cylinder 70. The boom cylinder 70 in this embodiment is provided with two ports (a first port and a second port). The first pipe section 91 connects these two ports to the hydraulic pump. That is, the first pipe section 91 includes a total of two pipe sections: one connecting the hydraulic pump to the first port, and another connecting the hydraulic pump to the second port. As shown in Figures 10 and 11(a), the first pipe section 91 passes through the internal spaces S20 and S30 of the side frame 20 and boom 30 before connecting to the boom cylinder 70. A detailed explanation follows. Note that in Figures 10 to 12, the two first pipe sections 91 are shown as a single line.

[0062] As shown in Figure 10, the first pipe section 91 is introduced into the side frame 20 from the hydraulic pump via the first opening 23. The first pipe section 91 is led out of the side frame 20 through the second opening 24 from the internal space S20 of the side frame 20 and introduced into the boom frame 31 via the third opening 31d. The first pipe section 91 introduced into the boom frame 31 extends through the internal space S30 of the boom 30 toward the fourth opening 31g.

[0063] Here, the boom 30 is provided with a boss portion 32 that crosses the internal space S30. Therefore, when assembling the first pipe portion 91, there is a concern that the boss portion 32 will get in the way when the first pipe portion 91 is fed from the third opening 31d toward the fourth opening 31g, making it difficult to assemble the first pipe portion 91. In this embodiment, a guide portion 33 is provided so that the pipe portion 90 can be guided above the boss portion 32. The guide portion 33 allows the first pipe portion 91 and the second pipe portion 92 to be guided toward the fourth opening 31g so as to avoid the boss portion 32 (pass above the boss portion 32). This suppresses the boss portion 32 from getting in the way when installing the first pipe portion 91, and allows the first pipe portion 91 to be easily positioned inside the boom 30.

[0064] The first pipe section 91, having passed through the boss section 32, is led out from the internal space S30 of the boom frame 31 onto the connecting frame 40 via the fourth opening 31g, as shown in Figures 10 to 12.

[0065] As described above, the first pipe section 91 of this embodiment is positioned within the side frame 20 and boom frame 31, extending from the first opening 23 to the fourth opening 31g. This prevents the first pipe section 91 from obstructing the worker's view, thereby improving visibility. Improved visibility also makes it easier to operate the front loader 10, thus improving work efficiency. Furthermore, the first pipe section 91 can be concealed by the side frame 20 and boom frame 31, improving aesthetics. In addition, even if the first pipe section 91 is damaged, it prevents the hydraulic fluid from scattering over a wide area.

[0066] In particular, in this embodiment, the first pipe section 91 is introduced into the side frame 20 from the first opening 23. This makes it difficult for the hose to be exposed on the sides of the side frame 20 and boom frame 31, and effectively prevents the first pipe section 91 from obstructing the worker's view.

[0067] Furthermore, as in this embodiment, if a posture maintenance mechanism 110 (see Figure 3) that operates in accordance with the swinging of the boom 30 is provided, arranging the first pipe section 91 within the side frame 20 and boom 30 prevents the posture maintenance mechanism 110 from interfering with and being damaged by the first pipe section 91.

[0068] As shown in Figure 11(a), the first pipe section 91, which is led onto the connecting frame 40, is branched by branch sections 91a provided on the connecting frame 40. Although not shown in Figure 11(a), there are two branch sections 91a (the same number as the first pipe section 91). These branch sections 91a are positioned offset from each other in the left-right direction.

[0069] The first pipe section 91, branched at the branching section 91a, extends toward the left and right boom frames 31. As shown in Figures 12 and 13, the first pipe section 91 is introduced into the storage space S31 via the front notch 31h. As shown in Figures 10 and 13, the first pipe section 91 extends upward and rearward through the storage space S31. In this way, the first pipe section 91 is guided from the connecting frame 40 to the vicinity of the left and right boom cylinders 70. The first pipe section 91 is connected to the left and right boom cylinders 70.

[0070] Thus, in this embodiment, the first pipe section 91 is arranged within the storage space S31, extending from the front notch 31h to the vicinity of the boom cylinder 70. This configuration allows the first pipe section 91 to be hidden within the storage space S31, making it difficult to see and improving visibility. Furthermore, even if the first pipe section 91 is damaged, it prevents the hydraulic fluid from scattering over a wide area.

[0071] Furthermore, the first pipe section 91, which is branched off at the branching section 91a, is composed of metal piping 91b, with some exceptions. Specifically, the first pipe section 91 is composed of metal piping 91b, except for the area near the left and right boom cylinders 70 (from below the boss section 32 to above the front end of the boom cylinder 70 in a side view). The part of the first pipe section 91 other than the metal piping 91b (near the boom cylinder 70) is composed of flexible hose 91c.

[0072] By constructing the first pipe section 91 with metal piping 91b, with a few exceptions, the length of the hose 91c can be shortened, thereby suppressing the sagging of the first pipe section 91. This prevents the first pipe section 91 from being exposed to the outside, thus preventing it from looking unsightly.

[0073] The second pipe section 92 connects the hydraulic pump and the bucket cylinder 80. The bucket cylinder 80 in this embodiment is provided with two ports (a first port and a second port). The second pipe section 92 connects these two ports to the hydraulic pump. That is, the second pipe section 92 includes a total of two pipe sections: one connecting the hydraulic pump to the first port, and another connecting the hydraulic pump to the second port. As shown in Figures 10 and 11(b), the second pipe section 92, like the first pipe section 91, is led onto the connecting frame 40 via the internal spaces S20 and S30 of the side frame 20 and boom 30. In Figures 10 to 13, the two second pipe sections 92 are shown as a single line.

[0074] As shown in Figure 11(b), the second pipe section 92 is branched by branch sections 92a provided on the connecting frame 40. Although not shown in Figure 11(b), there are two branch sections 92a (the same number as the second pipe section 92). These branch sections 92a are positioned offset from each other in the left-right direction. Furthermore, the branch sections 92a are positioned offset from the branch section 91a of the first pipe section 91 in the left-right direction. Thus, in this embodiment, all branch sections 91a and 92a are positioned offset from each other in the left-right direction.

[0075] The second pipe section 92, which branches off at the branching section 92a, extends toward the left and right boom frames 31. The second pipe section 92 extends substantially upward along the side surface 31b of the boom frame 31 and connects to the left and right bucket cylinders 80 (see Figures 2 and 13).

[0076] The third pipe section 93 is for connecting equipment other than the boom cylinder 70 and bucket cylinder 80 (e.g., snow blower, snow blade, and sweeper) to the hydraulic pump. Like the first pipe section 91, the third pipe section 93 includes two pipe sections. Note that in Figures 13 and 14, the two third pipe sections 93 are shown as a single line.

[0077] As shown in Figure 14, the third pipe section 93 extends from the hydraulic pump along the left side of the side frame 20 and boom 30. The third pipe section 93 is introduced into the storage space S31 through the rear notch 31h. The third pipe section 93 extends forward and downward through the storage space S31.

[0078] As shown in Figures 13 and 14, the third pipe section 93 within the storage space S31 is led onto the connecting frame 40 via the front notch 31h. In this way, by positioning the third pipe section 93 in the storage space S31 from the rear notch 31h to the front notch 31h, the third pipe section 93 can be hidden by the boom 30.

[0079] Furthermore, the third pipe section 93 is made of a metal pipe 93a extending at least from the front notch 31h to the rear notch 31h. This prevents the third pipe section 93 from sagging and being exposed to the outside.

[0080] The third pipe section 93, which is led onto the connecting frame 40, extends to the left along the connecting frame 40. The third pipe section 93 is exposed to the outside of the cover 100 through the opening 101a of the first cover 101, which will be described later (see Figure 15).

[0081] The configuration of the cover 100 will be described below with reference to Figures 11 to 13 and 15. The cover 100 is a hollow member that covers the pipe section 90, etc. As shown in Figure 15, the cover 100 comprises a first cover 101, a second cover 102, and a third cover 103.

[0082] The first cover 101 covers the tubular section 90 on the connecting frame 40. The first cover 101 is formed longitudinally along the axial direction of the connecting frame 40. The first cover 101 is formed in a substantially inverted U-shape with the opening facing downwards in a side (longitudinal) cross-sectional view. The first cover 101 is provided on the upper part of the connecting frame 40. The first cover 101 has an opening 101a.

[0083] The opening 101a is a portion through which the third pipe section 93 can be inserted. The opening 101a is formed on the front surface of the first cover 101. The opening 101a is covered by a stay 101b whose plate surface is oriented approximately in the front-to-back direction. The third pipe section 93 is provided so as to penetrate the stay 101b from front to back. In this way, the third pipe section 93 is exposed from the first cover 101.

[0084] As described above, in this embodiment, all branch sections 91a and 92a are arranged with their positions offset from each other in the left-right direction. This makes it possible to reduce the height of the first cover 101 that covers the branch sections 91a and 92a, and to miniaturize the cover 100.

[0085] The second cover 102 covers the fourth opening 31g, etc. The second cover 102 is formed in a roughly box shape with an opening on the right side. The second cover 102 is formed in a vertically elongated shape with a height greater than that of the first cover 101. As shown in Figure 11(a), the second cover 102 is provided with a first cutout 102a and a second cutout 102b.

[0086] The first cutout 102a is formed on the upper surface of the second cover 102. The first cutout 102a is formed appropriately so as not to interfere with the second pipe section 92. The second notch 102b is formed on the rear surface of the second cover 102. As shown in Figures 12 and 13, the second notch 102b is formed appropriately so as not to interfere with the first pipe section 91 and the third pipe section 93.

[0087] The second cover 102, configured as described above, is provided between the right boom frame 31 and the first cover 101. The second cover 102 covers the fourth opening 31g and the pipe section 90 near the fourth opening 31g. The second pipe section 92, which is branched at the branching section 92a, is led out to the outside of the cover 100 via the first notch 102a (see Figure 11(b)). The first pipe section 91, which is branched at the branching section 91a, is introduced from the cover 100 into the storage space S31 via the second notch 102b and the front notch 31h. The third pipe section 93 is introduced from the storage space S31 into the cover 100 via the second notch 102b and the front notch 31h.

[0088] The third cover 103 shown in Figure 15(a) covers the first pipe section 91 and the second pipe section 92. The third cover 103 is formed in a shape that is substantially symmetrical to the second cover 102. The third cover 103 has a first cutout 103a and a second notch 103b that are formed substantially the same as those of the second cover 102 (see Figure 11). The third cover 103 is provided between the left boom frame 31 and the first cover 101. The third cover 103 covers the first pipe section 91 and the second pipe section 92 that extend from the branching sections 91a and 92a to the left boom frame 31. The first pipe section 91 and the second pipe section 92, which are branched at branching section 92a, are led out to the outside of the cover 100 via the first cutout 103a and the second notch 103b.

[0089] As described above, the front loader 10 according to this embodiment comprises a boom 30 and a side frame 20 that pivotably supports the boom 30 and has a first opening 23 through which pipe sections 90 (first pipe section 91 and second pipe section 92 in this embodiment) for forming a flow path for hydraulic fluid can be inserted.

[0090] This configuration allows the pipe section 90 to be positioned within the side frame 20, thus preventing the pipe section 90 from obstructing the worker's view. This improves visibility. Furthermore, the pipe section 90 can be concealed by the side frame 20, improving the aesthetic appearance.

[0091] Furthermore, the first opening 23 is formed on one side of the side frame 20 in the left-right direction (the left side in this embodiment) (see Figure 7).

[0092] This configuration allows the pipe section 90 to be introduced into the side frame 20 from the left and right outer sides of the side frame 20.

[0093] Furthermore, a second opening 24 is formed on the side frame 20 facing the boom 30, through which the pipe portion 90 can be inserted (see Figure 8).

[0094] This configuration allows the pipe section 90 to be led out from inside the side frame 20 toward the boom 30.

[0095] Furthermore, the boom 30 has a third opening 31d formed on the surface facing the side frame 20 through which the pipe portion 90 can be inserted, and a fourth opening 31g that is different from the third opening 31d.

[0096] By configuring it in this way, the pipe section 90 can effectively prevent obstructing the worker's view, thereby effectively improving visibility.

[0097] Furthermore, the front loader 10 comprises a connecting frame 40 that connects the left and right booms 30, and a pipe section 90 that is led out from inside the boom 30 through the fourth opening 31g onto the connecting frame 40, branches on the connecting frame 40 and connects to the left and right boom cylinders 70 and the left and right bucket cylinders 80 (see Figures 4 and 5).

[0098] This configuration allows the branch sections 91a and 92a of the pipe section 90 to be consolidated onto the connecting frame 40. This makes it easier to assemble and maintain the pipe section 90.

[0099] Furthermore, the front loader 10 is further provided with a first cover 101 that covers the pipe section 90 on the connecting frame 40.

[0100] By configuring it in this way, the pipe section 90 on the connecting frame 40 can be hidden by the first cover 101, thereby improving the aesthetic appearance.

[0101] Furthermore, the first cover 101 has an opening 101a (see Figure 15).

[0102] By configuring it in this way, hydraulic pressure can be utilized through the opening 101a.

[0103] Furthermore, the front loader 10 is further provided with a second cover 102 that covers the fourth opening 31g.

[0104] By configuring it in this way, the fourth opening 31g and the pipe section 90 leading out from the fourth opening 31g can be hidden by the second cover 102, thereby improving the aesthetic appearance.

[0105] Furthermore, the boom 30 can be fitted with a posture maintenance mechanism 110 that operates in accordance with the swinging of the boom 30 to maintain the posture of the bucket 50 (work tool) connected to the boom 30. The boom 30 is provided with a boss portion 32 (mounting portion) for which the posture maintenance mechanism 110 is attached, at least a portion of which is located inside the boom 30, and a guide portion 33 for which the pipe portion 90 is guided to avoid the boss portion 32, at least a portion of which is located inside the boom 30.

[0106] This configuration allows the pipe section 90 to be easily positioned within the boom 30.

[0107] The bucket 50 according to this embodiment is one form of a work tool according to the present invention. Furthermore, the boss portion 32 according to this embodiment is one form of the mounting portion according to the present invention.

[0108] Although embodiments of the present invention have been described above, the present invention is not limited to the above configuration, and various modifications are possible within the scope of the invention as described in the claims.

[0109] For example, although the first opening 23 is formed on the left side of the side frame 20, the location where the first opening 23 is formed is not particularly limited and can be changed as desired. For example, the first opening 23 may be formed on the bottom surface or the right side surface 21 of the right side frame 20. Alternatively, the first opening 23 may be formed on the left side frame 20 instead of the right side frame 20.

[0110] Furthermore, although the second opening 24 is formed on the upper part of the connection portion 22 of the side frame 20, the location where the second opening 24 is formed is not particularly limited and can be changed as desired. For example, the second opening 24 may be formed in a location other than the upper part of the connection portion 22.

[0111] Furthermore, although the third opening 31d is formed on the bottom surface 31c of the boom frame 31, the location where the third opening 31d is formed is not particularly limited and can be changed as desired.

[0112] Furthermore, although the fourth opening 31g is formed on the left side of the boom frame 31, the location where the fourth opening 31g is formed is not particularly limited and can be changed as desired.

[0113] Furthermore, although the opening 101a of the first cover 101 is formed on the front side surface of the first cover 101, the location where the opening 101a is formed is not particularly limited and can be changed as desired.

[0114] Furthermore, although the boss portion 32 is shown with both left and right ends protruding from the boom 30, this is just one example, and it is sufficient if at least a part of it is located within the boom 30.

[0115] Furthermore, although the guide section 33 is shown to be almost entirely located within the boom 30, this is just one example, and it is sufficient if at least a part of it is located within the boom 30.

[0116] Furthermore, although the first pipe section 91 and the second pipe section 92 are provided to pass above the boss section 32, this is just one example, and the location where the first pipe section 91, etc., pass over the boss section 32 is not particularly limited. For example, the first pipe section 91, etc., may be provided to pass below the boss section 32. In this case, the guide section 33 may be provided to guide the first pipe section 91, etc., below the boss section 32, for example, extending from the boss section 32 to the upper surface 31a of the boom frame 31.

[0117] Furthermore, although the pipe section 90 is provided with a third pipe section 93, this is just one example, and the third pipe section 93 does not need to be installed if hydraulic equipment such as a snow blower is not provided.

[0118] Furthermore, while the front loader 10 is equipped with a posture maintenance mechanism 110, this is merely an example, and the present invention is also applicable to front loaders that do not have a posture maintenance mechanism 110. [Explanation of Symbols]

[0119] 10 Front Loader 20 Side Frames 23 First opening 30 Boom 90 Pipe section

Claims

1. The boom and A side frame that swingably supports the boom and has a first opening through which a pipe for forming a flow path for hydraulic fluid can be inserted, It is equipped with, The aforementioned boom included, A posture maintenance mechanism can be attached that operates in accordance with the swinging of the boom, thereby maintaining the posture of the work tool connected to the boom. The aforementioned boom, A boom frame formed in a hollow shape, having an internal space enclosed by the top, sides, and bottom, At least a portion of the boom frame is located in the internal space of the boom frame and includes a mounting portion for attaching the attitude maintenance mechanism, At least a portion of the guide portion is located in the internal space of the boom frame and guides the pipe portion through the internal space of the boom frame so as to avoid the mounting portion, It is equipped with, The aforementioned guide section is Within the internal space of the boom frame, a portion is provided that extends between the mounting portion and the bottom surface of the boom frame. Front loader.

2. The first opening is, Formed on one side surface in the left-right direction of the side frame, The front loader according to claim 1.

3. On the side of the side frame facing the boom, A second opening is formed through which the aforementioned pipe portion can be inserted. The front loader according to claim 2.

4. The aforementioned boom included, A third opening is formed on the surface facing the side frame, through which the pipe portion can be inserted, A fourth opening different from the third opening, Formed A front loader according to any one of claims 1 to 3.

5. A connecting frame that connects the left and right booms, The pipe section is led out from inside the boom through the fourth opening onto the connecting frame, branches on the connecting frame and is connected to the left and right boom cylinders and the left and right bucket cylinders, It further possesses, The front loader according to claim 4.

6. The connecting frame further comprises a first cover that covers the pipe portion on the aforementioned connecting frame, The front loader according to claim 5.

7. The first cover includes, An opening is formed. The front loader according to claim 6.

8. The system further comprises a second cover that covers the fourth opening, A front loader according to any one of claims 5 to 7.

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