Front loader attitude maintenance mechanism and front loader

Abstract

To provide an attitude maintenance mechanism for a front loader capable of improving visibility.SOLUTION: An attitude maintaining mechanism 100 for a front loader 10 that maintains the attitude of a bucket 50 connected to a boom 30 by operating in response to swinging of the boom 30 having a pair of left and right boom frames 31 comprises a first link member 102 swingable with respect to a side frame 20 of the front loader 10, and a second link member 104 that is swingably provided with respect to the boom frame 31 and that is connected to the first link member 102 and a bucket cylinder 80. A pair of the first link member 102 and the second link member 104 are provided on both sides of the boom frame 31.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a posture maintaining mechanism for a front loader that maintains the posture of a working tool connected to a boom and the technology of a front loader.

Background Art

[0002] Conventionally, the technology of a posture maintaining mechanism for a front loader that maintains the posture of a working tool connected to a boom has been known. For example, it is as described in Patent Document 1.

[0003] The posture maintaining mechanism described in Patent Document has a link rod and a connecting body. The link rod is swingably supported by a sub-frame (side frame) and is arranged at an interval above the boom. The connecting body is swingably supported by the boom. The connecting body is connected to the link rod and the working machine cylinder respectively. The link rod and the connecting body are swung according to the raising and lowering of the boom. By this swinging, the posture of the bucket is maintained when the boom is raised and lowered.

[0004] However, in the posture maintaining mechanism described in Patent Document 1, the link rod and the like arranged above the boom may block the operator's view, resulting in a possible deterioration in visibility.

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 posture maintaining mechanism for a front loader and 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, a posture maintenance mechanism for a front loader that maintains the posture of a work tool connected to a boom by operating in accordance with the swinging of a boom having a pair of left and right boom frames, comprising: a first link member that is swingable with respect to the side frame of the front loader; and a second link member that is swingably provided with respect to the boom frame and connected to the first link member and a bucket cylinder, wherein the first link member and the second link member are provided as a pair on the left and right sides of the boom frame, and the insertion portion through which the swing axis of the second link member is inserted is formed to be longer than the width of the boom frame and is provided to penetrate the side surface of the boom frame and cross the internal space of the boom frame. Furthermore, the first link member is provided with a recess formed by cutting out the lower end of the first link member so that the first link member does not interfere with the pivot axis of the boom frame. It is. According to one aspect of this disclosure, the posture maintenance mechanism can suppress obstruction of the worker's field of vision, thereby improving visibility.

[0009] In one embodiment of the present disclosure, the first link member is arranged so as not to overlap with the boom frame in a plan view. According to one aspect of this disclosure, the first link member can be prevented from interfering with the boom frame, thereby improving design flexibility.

[0010] In one embodiment of the present disclosure, the first link member and the second link member are arranged such that at least a portion of them overlap with respect to the boom in a side view, regardless of the swing angle of the boom. According to one aspect of this disclosure, the posture maintenance mechanism can effectively suppress obstruction of the worker's field of vision, thereby effectively improving visibility.

[0011] In one embodiment of this disclosure, the left and right pair of first link members are provided with bent portions that are bent inward from each other. According to one aspect of this disclosure, the strength of the first link member can be improved by the bending portion.

[0012] In one embodiment of the present disclosure, the bent portion is formed to extend from the pivot axis of the first link member to the connecting portion between the first link member and the second link member. According to one aspect of this disclosure, the strength of the first link member can be effectively improved.

[0013] In one embodiment of the present disclosure, the second link member comprises a first member and a second member fixed to one side of the first member. According to one aspect of this disclosure, one of the first member and the second member can be moved away from the boom frame to secure a gap with the boom frame.

[0014] In one embodiment of this disclosure, the pivot axis of the first link member, the connecting portion between the first link member and the second link member, and the connecting portion between the second link member and the bucket cylinder are located substantially on the same straight line in a side view. According to one aspect of this disclosure, the posture maintenance mechanism can effectively suppress obstruction of the worker's field of vision, thereby effectively improving visibility.

[0015] In one embodiment of this disclosure, the left and right pair of first link members are formed symmetrically with respect to each other, and the left and right pair of second link members are formed symmetrically with respect to each other. According to one aspect of this disclosure, a sense of unity can be achieved between the pair of left and right first link members and the pair of left and right second link members, thereby improving aesthetics.

[0016] In one embodiment of this disclosure, the front loader is equipped with the attitude maintenance mechanism. According to one aspect of this disclosure, the height position of the posture maintenance mechanism can be lowered, and visibility can be improved by suppressing the obstruction of the worker's field of view by the posture maintenance mechanism.

[0017] In one aspect of the present disclosure, the swing axis of the second link member is provided so as to cross the internal space of the boom. According to one aspect of the present disclosure, the swing axis of the second link member can be arranged at a relatively low position, and it is possible to suppress the second link member from blocking the operator's view.

[0018] In one aspect of the present disclosure, it includes the boom and a pipe portion disposed inside the boom, and the boom includes a support portion that supports the swing axis of the second link member, and at least a part of the pipe portion is disposed inside the boom, and a guiding portion that guides the pipe portion so as to avoid the support portion. According to one aspect of the present disclosure, by guiding the pipe portion by the guiding portion, the pipe portion can be easily arranged in the boom.

Effect of the Invention

[0019] According to one aspect of the present disclosure, visibility can be improved.

Brief Description of the Drawings

[0020] [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 a front loader. [Figure 3] Similarly, a left side view. [Figure 4] Similarly, a right side cross-sectional view. [Figure 5] A perspective view showing a side frame, a boom, a boom cylinder, and a posture maintaining mechanism. [[ID=3​​​​​​​​​​​​​ [Figure 11] Left side view showing the boom in the raised position. [Figure 12] Left side view showing the boom raised to its maximum height. [Figure 13] Left side view showing the front loader with the attitude maintenance mechanism removed. [Modes for carrying out the invention]

[0021] The following describes the overall configuration of a tractor 1 equipped with a front loader 10 according to one embodiment of the present invention.

[0022] As shown in Figure 1, the tractor 1 mainly consists of a machine frame 2, engine 3, transmission case 4, front wheels 5, rear wheels 6, bonnet 7, cabin 8, steering wheel 9, and front loader 10.

[0023] 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.

[0024] 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.

[0025] 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 control devices, and a seat for the worker.

[0026] A front loader 10 is mounted on the front of tractor 1. The detailed configuration of the front loader 10 will be described below with reference to Figures 2 through 10.

[0027] 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, and attitude maintenance mechanism 100, etc.

[0028] The side frames 20 shown in Figures 2 and 3 support the boom 30, which will be described later, in a swingable manner. The side frames 20 are formed in a hollow shape. 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. As shown in Figures 4 and 5, the right-side side frame 20 is equipped with a first opening 21 and a second opening 22.

[0029] The first opening 21 and the second opening 22 are portions through which the pipe section 90, described later, can be inserted. The first opening 21 is formed on the left side of the side frame 20. The second opening 22 is formed on the upper surface of the side frame 20.

[0030] The boom 30 is pivotably supported by the left and right side frames 20. The boom 30 is positioned to extend forward and downward from the top of the side frames 20. As shown in Figures 4 and 10, the boom 30 comprises a boom frame 31, a pivot shaft 32, a boss portion 33, a guide portion 34, a closing portion 35, and a side plate 36. The boom frame 31, pivot shaft 32, boss portion 33, closing portion 35, and side plate 36 are provided in pairs, one on the left and one on the right. The guide portion 34 is provided on the right boom frame 31. The configuration of the boom frame 31, etc., will be described below, using the right boom frame 31, etc., as an example.

[0031] The boom frame 31 forms the main structure of the boom 30. The boom frame 31 is formed in a hollow shape. The right boom frame 31 is equipped with a third opening 31a, a fourth opening 31b, a through hole 31c, and a slit 31d. The left boom frame 31 is configured similarly to the right boom frame 31, except that it does not have the third opening 31a and the fourth opening 31b.

[0032] The third opening 31a and the fourth opening 31b are portions through which the pipe section 90 can be inserted. The third opening 31a is formed at the rear end of the boom frame 31. The fourth opening 31b is formed at the front lower part of the boom frame 31. The through hole 31c is a hole that penetrates the boom frame 31 vertically. The through hole 31c is formed in the middle of the front-to-rear part of the upper surface of the boom frame 31 (forward of the third opening 31a and above the fourth opening 31b). The slit 31d is a horizontally elongated hole that penetrates the boom frame 31 horizontally. The slit 31d is formed below the through hole 31c.

[0033] The pivot shaft 32 supports the boom frame 31 so that it can pivot relative to the side frame 20. The pivot shaft 32 is formed in a cylindrical shape with its axis oriented left to right. In this embodiment, the pivot shaft 32 is an axial member that is longer than the left-right width of the side frame 20 and the boom frame 31. The pivot shaft 32 is inserted through the side frame 20 and the boom frame 31.

[0034] The boss portion 33 is for attaching the second link member 104 of the attitude maintenance mechanism 100, which will be described later. The boss portion 33 is formed in a substantially cylindrical shape with its axis oriented left to right. The length of the boss portion 33 in the axial direction is formed to be longer than the left-right width of the boom frame 31. The boss portion 33 is provided so as to penetrate both the left and right sides of the boom frame 31. In this way, the boss portion 33 is positioned to cross the internal space S30 of the boom 30. The boss portion 33 is fixed to both the left and right sides of the boom frame 31 by welding or the like.

[0035] The guide section 34 is for guiding the pipe section 90, which will be described later. The guide section 34 is formed in the shape of a plate with its plate surface oriented approximately vertically. The left-right width of the guide section 34 is formed to be approximately the same as the left-right width of the boom frame 31. The guide section 34 is fixed to the slit 31d of the right boom frame 31 by welding or the like. In this way, the guide section 34 is positioned almost entirely inside the boom 30. The guide section 34 is also provided so as to extend between the boss section 33 and the bottom surface of the boom frame 31. More specifically, the guide section 34 is formed to extend approximately in the front-rear direction in a side view from near the top of the boss section 33 to the bottom surface of the boom frame 31 so as to guide the pipe section 90 above the boss section 33.

[0036] The closing portion 35 is a plate-shaped member that closes the through hole 31c of the boom frame 31. The closing portion 35 is fixed to the boom frame 31 after the boss portion 33 and guide portion 34 are fixed to the boom frame 31. This allows the boss portion 33 and guide portion 34 to be easily welded into the boom frame 31 through the through hole 31c.

[0037] The side plates 36 are formed in a plate shape with their surface oriented approximately left to right. The side plates 36 are provided on the left and right sides of the boom frame 31. The side plates 36 are equipped with boss portions 36a.

[0038] The boss portion 36a shown in Figure 10 is a part that can be connected to the bucket cylinder 80, which will be described later. The boss portion 36a is formed in a substantially cylindrical shape with its axis oriented left and right. The boss portion 36a is formed to protrude from the side surface of the side plate 36 to one side on the left or right (outward on the left or right side when the boom frame 31 located between the side plates 36 is used). The boss portion 36a is used when the attitude maintenance mechanism 100 is not provided on the front loader 10. In this case, the boss portion 36a is connected to the bucket cylinder 80 via the connecting shaft 81 (see Figure 13).

[0039] The connecting frame 40 shown in Figures 2 and 3 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.

[0040] The bucket 50 is formed to open forward. The bucket 50 is pivotably connected to the front end of the boom 30.

[0041] 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 lower part of each of the left and right boom frames 31 (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.

[0042] 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.

[0043] 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. The bucket cylinder 80 shown in Figures 2 and 3 is pivotably connected to the boom 30 via the second link member 104 of the attitude maintenance mechanism 100. A pair of bucket cylinders 80 are provided, one on the left and one on the right.

[0044] The pipe section 90 shown in Figures 2 and 4 is for forming a flow path for hydraulic fluid. The pipe section 90 includes a first pipe section connecting the tractor 1's pump (not shown) to the boom cylinder 70, and a second pipe section connecting the pump to the bucket cylinder 80. The pipe section 90 is introduced into the side frame 20 through a first opening 21, and then introduced into the boom 30 from the side frame 20 through a second opening 22 and a third opening 31a. The pipe section 90 is also led out from inside the boom 30 onto the connecting frame 40 through a fourth opening 31b, and connected to the boom cylinder 70 and the bucket cylinder 80.

[0045] The posture maintenance mechanism 100 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 100 are provided, one on the left and one on the right. Since the left and right posture maintenance mechanisms 100 have substantially the same configuration, the configuration of the posture maintenance mechanism 100 will be explained below using the right posture maintenance mechanism 100 as an example, and the explanation of the configuration of the left posture maintenance mechanism 100 will be omitted. As shown in Figures 5 and 6, the posture maintenance mechanism 100 comprises a fixed member 101, a first link member 102, a first swing shaft 103, a second link member 104, a second swing shaft 105, a first connecting shaft 106, and a second connecting shaft 107.

[0046] The fixing members 101 shown in Figures 5, 6, and 8 are members that are fixed to the upper part of the side frame 20. The fixing members 101 are formed in the shape of a plate with the plate surface oriented in a substantially left-right direction. A pair of fixing members 101 are provided, one on the left and one on the right. The fixing members 101 are also formed symmetrically to each other. The left and right fixing members 101 are connected to each other by substantially cylindrical boss portions 101a with their axes oriented left and right. The left and right fixing members 101 are fixed to the sides of the side frame 20. The fixing members 101 are provided with recesses 101b.

[0047] The recess 101b shown in Figures 6, 8, and 9 is for avoiding interference with the pivot shaft 32. The recess 101b is formed in a roughly inverted U-shape when viewed from the side. The recess 101b is formed to extend from the lower end to the upper part of the fixing member 101.

[0048] The first link member 102 is a member provided between the fixing member 101 and the second link member 104, which will be described later. The first link member 102 is formed in the shape of a plate with its plate surface oriented substantially in the left-right direction. The first link member 102 is also formed to extend substantially in the front-rear direction. A pair of first link members 102 are provided, one on the left and one on the right. The first link members 102 are also formed symmetrically to each other. The first link member 102 is equipped with a bent portion 102a and a recess 102b.

[0049] The bent portion 102a is a portion formed by bending the plate surface of the first link member 102. The bent portion 102a is formed at the upper end of the first link member 102. In this embodiment, the bent portion 102a is formed by bending the plate surfaces of the left and right first link members 102 so that they are close to each other (inward). The bent portion 102a is also formed to extend from the rear end to the front end of the first link member 102 (see the range R102 of the bent portion 102a shown in Figure 8).

[0050] The recess 102b is designed to avoid interference with the pivot shaft 32. The recess 102b is formed in an upwardly convex concave shape. The recess 102b is formed at the rear lower end of the first link member 102.

[0051] The first link members 102, configured as described above, are positioned on the left and right sides of the boom frame 31 and the fixing member 101. Thus, a pair of first link members 102 are provided, one on each side of the boom frame 31. The left and right first link members 102 overlap with the boom frame 31 and the fixing member 101 in a side view (see Figure 3). Also, as shown in Figure 7(a), the left and right first link members 102 do not overlap with the boom frame 31 in a plan view.

[0052] The first pivot shaft 103 shown in Figures 6, 8, and 9 is for pivotally supporting the first link member 102 relative to the side frame 20. The first pivot shaft 103 is formed in a substantially cylindrical shape with its axis oriented left and right. The first pivot shaft 103 is inserted through the rear ends of the left and right first link members 102 and the boss portion 101a of the fixing member 101. The first pivot shaft 103 is positioned above and behind the pivot shaft 32.

[0053] The second link member 104 is a member that connects the bucket cylinder 80 and the first link member 102. The second link member 104 is formed in the shape of a plate with its surface oriented approximately left to right. The second link member 104 is formed in the shape of a roughly triangular shape when viewed from the side. A pair of second link members 104 are provided, one on the left and one on the right. The second link members 104 are also formed symmetrically to each other. As shown in Figures 6 and 8, the second link member 104 comprises a first member 104a and a second member 104b.

[0054] The first member 104a is a member that forms the rear part of the second link member 104. The first member 104a is formed in a substantially plate shape. The second member 104b is a member that forms the front part of the second link member 104. The second member 104b is formed in a substantially plate shape. The second member 104b is fixed to one side of the first member 104a. In this way, the second member 104b is formed integrally with the first member 104a.

[0055] As described above, the second link members 104 are positioned on the left and right sides of the boom frame 31 and side plates 36, as shown in Figures 6 and 7. Thus, a pair of second link members 104 are provided, one on each side of the boom frame 31. The left and right second link members 104 overlap with the boom frame 31 and side plates 36 in a side view (see Figure 3). Also, as shown in Figure 7(a), the left and right second link members 104 do not overlap with the boom frame 31 in a plan view.

[0056] As shown in Figure 7(b), the second member 104b is positioned to the left and right outer sides of the first member 104a, with respect to the boom frame 31. Therefore, the gap between the second member 104b and the side plate 36 is larger than the gap between the first member 104a and the side plate 36. In this embodiment, the second member 104b prevents interference with the boss portion 36a of the side plate 36 (see Figures 7(b) and 8).

[0057] The second pivot shaft 105 shown in Figures 4, 6, and 8 is for supporting the second link member 104 so that it can pivot relative to the boom 30. The second pivot shaft 105 is formed in a substantially cylindrical shape with its axis oriented left and right. The second pivot shaft 105 is inserted through the lower ends of the left and right second link members 104 and the boss portion 33 of the boom 30, and is supported by the boss portion 33. In this way, the second pivot shaft 105 is positioned at a relatively low height (to the extent that it crosses the internal space S30 of the boom 30). This allows the second link member 104 to be supported at a relatively low position, thus preventing the second link member 104 from obstructing the operator's view.

[0058] The first connecting shaft 106 shown in Figures 6 and 8 is for connecting the first link member 102 and the second link member 104. The first connecting shaft 106 is formed in a substantially cylindrical shape with its axis oriented left and right. In this embodiment, the first connecting shaft 106 is an axial member that is longer than the left-right width of the first link member 102. The first connecting shaft 106 is fixed to the rear upper end of the second link member 104 and connected to the front end of the first link member 102.

[0059] The second connecting shaft 107 is for connecting the second link member 104 and the bucket cylinder 80. The second connecting shaft 107 is formed in a substantially cylindrical shape with its axis oriented left and right. In this embodiment, a bolt that can be inserted through the left and right second link members 104 is used as the second connecting shaft 107. The second connecting shaft 107 connects the front upper end of the second link member 104 and the bucket cylinder 80 without being inserted through the boss portion 36a of the side plate 36.

[0060] As shown in Figure 8, the second connecting shaft 107 is positioned in the vicinity of a straight line L1 passing through the first pivot shaft 103 and the first connecting shaft 106 in a side view. The first connecting shaft 106, the first pivot shaft 103, and the second connecting shaft 107 are also positioned in a direction that slopes downwards towards the front. In this way, when the bucket 50 is in contact with the ground, the first pivot shaft 103, the first connecting shaft 106, and the second connecting shaft 107 are positioned in approximately the same straight line, allowing the connection portion (second connecting shaft 107) between the second link member 104 and the bucket cylinder 80 to be positioned at a relatively low position.

[0061] 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, as shown in Figures 3, 11, and 12. In this way, the boom 30 is raised and lowered. The first link member 102 and the second link member 104 are swung along with the raising and lowering of the boom 30. The posture maintenance mechanism 100 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 102 and 103.

[0062] In this embodiment, the posture maintenance mechanism 100 has a first link member 102 and a second link member 104 positioned on either side of the boom frame 31. This configuration makes it less likely for the first link member 102 and the second link member 104 to interfere with the boom frame 31, thereby improving the design freedom of the posture maintenance mechanism 100. As a result, for example, the height position of the first link member 102, etc. can be lowered to the extent that it overlaps with the boom frame 31 in a side view. This reduces the obstruction of the operator's view by the first link member 102, etc., and improves visibility. Furthermore, the improved visibility makes it easier to perform work with the front loader 10, thus improving work efficiency.

[0063] In particular, the first link member 102 and the second link member 104 in this embodiment are arranged so as not to overlap with the boom frame 31 in a plan view. As a result, no matter how much the height of the first link member 102, etc., is lowered, it will not interfere with the boom frame 31, thereby effectively improving the degree of design freedom.

[0064] Furthermore, the first link member 102 and the second link member 104 overlap with the boom 30 almost seamlessly in a side view, regardless of the boom 30's swing angle. More specifically, the first link member 102 and the second link member 104 overlap with the boom 30 without gaps in a side view, regardless of the boom 30's swing angle, except for the recess 102b. This configuration suppresses the protrusion of the first link member 102 and the second link member 104 from the boom 30, effectively improving visibility. It also suppresses the unsightly appearance of the attitude maintenance mechanism 100, improving aesthetics.

[0065] As shown in Figure 4, the pipe section 90 is positioned inside the side frame 20 and boom 30. This prevents interference between the pipe section 90 and the attitude maintenance mechanism 100, and prevents damage to the pipe section 90 caused by interference between the attitude maintenance mechanism 100 and the pipe section 90. Furthermore, the pipe section 90 can be hidden by the side frame 20, etc., improving the aesthetics. In addition, even if the pipe section 90 is damaged, it is possible to prevent the hydraulic fluid from scattering over a wide area.

[0066] Here, the boom 30 is provided with a boss portion 33 that crosses the internal space S30. Therefore, when assembling the pipe portion 90, if the pipe portion 90 is fed from the third opening 31a toward the fourth opening 31b, the boss portion 33 will get in the way, raising concerns that it will be difficult to assemble the pipe portion 90. In this embodiment, a guide portion 34 is provided so that the pipe portion 90 can be guided above the boss portion 33. The guide portion 34 allows the pipe portion 90 to be guided toward the fourth opening 31b so as to avoid the boss portion 33 (pass above the boss portion 33). This suppresses the boss portion 33 from getting in the way when installing the pipe portion 90, and makes it easy to position the pipe portion 90 inside the boom 30.

[0067] As described above, the bucket cylinder 80 is connected to the second link member 104 at a relatively low position (near the straight line L1). With this configuration, as shown in Figures 3 and 13, a common bucket cylinder 80 can be used regardless of whether the attitude maintenance mechanism 100 is present or not. This makes it easy to retrofit the attitude maintenance mechanism 100.

[0068] As described above, the posture maintenance mechanism 100 according to this embodiment is a posture maintenance mechanism 100 for a front loader 10 that maintains the posture of a bucket 50 (work tool) connected to a boom 30 by operating in accordance with the swinging of a boom 30 having a pair of left and right boom frames 31, and comprises a first link member 102 that is swingable with respect to the side frame 20 of the front loader 10, and a second link member 104 that is swingably provided with respect to the boom frame 31 and connected to the first link member 102 and the bucket cylinder 80, and the first link member 102 and the second link member 104 are provided as a pair on the left and right sides of the boom frame 31.

[0069] By configuring it in this way, the height position of the posture maintenance mechanism 100 can be lowered, which reduces the obstruction of the worker's field of view and improves visibility.

[0070] Furthermore, the first link member 102 is positioned so as not to overlap with the boom frame 31 in a plan view (see Figure 7).

[0071] This configuration allows for increased design flexibility.

[0072] Furthermore, the first link member 102 and the second link member 104 are arranged so that at least a portion of them overlap with the boom 30 in a side view, regardless of the swing angle of the boom 30 (see Figures 3, 11, and 12).

[0073] This configuration effectively improves visibility. It also helps to prevent the design from becoming unsightly, thereby enhancing its aesthetic appeal.

[0074] Furthermore, the pair of left and right first link members 102 are each provided with bent portions 102a that are bent inward from each other (see Figure 9).

[0075] By configuring it in this way, the strength of the first link member 102 can be improved by the bent portion 102a.

[0076] Furthermore, the bent portion 102a is formed to extend from the pivot axis of the first link member 102 (rear end, first pivot axis 103) to the connecting portion between the first link member 102 and the second link member 104 (front end, first connecting axis 106) (see Figure 8).

[0077] By configuring it in this way, the strength of the first link member 102 can be effectively improved.

[0078] Furthermore, the second link member 104 comprises a first member 104a and a second member 104b fixed to one side of the first member 104a (see Figure 7(b)).

[0079] By configuring it in this way, one of the first member 104a and the second member 104b (the second member 104b in Figure 7(b)) can be moved away from the boom frame 31, thereby securing a gap between it and the boom frame 31.

[0080] Furthermore, the pivot axis of the first link member 102 (first pivot axis 103), the connecting portion between the first link member 102 and the second link member 104 (first connecting axis 106), and the connecting portion between the second link member 104 and the bucket cylinder 80 (second connecting axis 107) are located substantially on the same straight line when viewed from the side (see Figure 8).

[0081] By configuring it in this way, the height position of the connection portion (second connecting shaft 107) between the second link member 104 and the bucket cylinder 80 can be lowered.

[0082] Furthermore, the pair of left and right first link members 102 are formed symmetrically with respect to each other, and the pair of left and right second link members 104 are formed symmetrically with respect to each other.

[0083] This configuration allows for a sense of unity between the pair of left and right first link members 102 and the pair of left and right second link members 104, thereby improving aesthetics. Furthermore, the first link members 102 and the second link members 104 can be attached to either the left or right side frames 20 or the left or right boom frames 31 (parts can be shared). In addition, the strength balance between the left and right link members 102 and 104 is improved, preventing malfunctions (such as deformation of the link members 102 and 104).

[0084] Furthermore, the front loader 10 according to this embodiment is equipped with the attitude maintenance mechanism 100.

[0085] By configuring it in this way, the height position of the posture maintenance mechanism 100 can be lowered, which reduces the obstruction of the worker's field of view and improves visibility.

[0086] Furthermore, the pivot axis (second pivot axis 105) of the second link member 104 is provided so as to cross the internal space S30 of the boom 30 (see Figure 4).

[0087] By configuring it in this way, the pivot axis (second pivot axis 105) of the second link member 104 can be positioned at a relatively low position, thereby preventing the second link member 104 from obstructing the worker's view.

[0088] Furthermore, the apparatus comprises a boom 30 and a pipe section 90 disposed inside the boom 30, wherein the boom 30 includes a boss section 33 (support section) that supports the pivot axis (second pivot axis 105) of the second link member 104, and a guide section 34 which at least a portion of which is disposed inside the boom 30 and guides the pipe section 90 so as to avoid the boss section 33.

[0089] This configuration allows the pipe section 90 to be easily positioned within the boom 30.

[0090] The bucket 50 according to this embodiment is one form of a work tool according to the present invention. Furthermore, the boss portion 33 according to this embodiment is one form of the support portion according to the present invention.

[0091] 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.

[0092] For example, the first link member 102 is provided with a bent portion 102a and a recess 102b, but the configuration of the first link member 102 is not limited to this and can be changed as desired.

[0093] Furthermore, although the first link member 102 is designed not to overlap with the boom frame 31 in a plan view, the positional relationship between the first link member 102 and the boom frame 31 in a plan view is not particularly limited. For example, a part of the first link member 102 may overlap with the boom frame 31 in a plan view.

[0094] Furthermore, although the second link member 104 comprises a first member 104a and a second member 104b, the configuration of the second link member 104 is not limited to this and can be changed as desired. For example, the second link member 104 may be made of a single plate-like member. Alternatively, the second link member 104 may be formed so as to avoid interference with the boss portion 36a by appropriately bending the plate surface.

[0095] Furthermore, although the first link member 102 and the second link member 104 overlap with the boom 30 in a side view, the positional relationship between the first link member 102, etc. and the boom frame 31 in a side view is not particularly limited. For example, of the first link member 102 and the second link member 104, only the second link member 104 may overlap with the boom 30 in a side view.

[0096] Furthermore, the first pivot shaft 103, the first connecting shaft 106, and the second connecting shaft 107 are positioned approximately on the same straight line when viewed from the side, but the relative positions of the first pivot shaft 103, the first connecting shaft 106, and the second connecting shaft 107 can be arbitrarily changed.

[0097] Furthermore, although the first link member 102 is formed symmetrically, it is not limited to this, and may, for example, be formed asymmetrically.

[0098] Furthermore, although the second link member 104 is formed symmetrically, it is not limited to this and may be formed asymmetrically, for example.

[0099] Furthermore, although the boss section 33 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.

[0100] Furthermore, although the guide section 34 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.

[0101] Furthermore, although the pipe section 90 is provided to pass above the boss section 33, this is just one example, and the location where the pipe section 90 passes above the boss section 33 is not particularly limited. For example, the pipe section 90 may be provided to pass below the boss section 33. In this case, the guide section 34 is appropriately provided to guide the pipe section 90 below the boss section 33.

[0102] Furthermore, although at least a portion of the pipe section 90 is positioned within the side frame 20 and boom 30, this is merely an example, and the arrangement of the pipe section 90 is not particularly limited. [Explanation of Symbols]

[0103] 10 Front Loader 20 Side Frames 30 Boom 31 Boom Frame 50 buckets 80 Bucket Cylinder 100 Posture maintenance mechanism 102 First link member 103 Second link member

Claims

1. A posture maintenance mechanism for a front loader, which operates in response to the swinging of a boom comprising a pair of left and right boom frames, thereby maintaining the posture of a work tool connected to the boom, A first link member that is pivotable relative to the side frame of the front loader, A second link member is provided so as to be swingable relative to the boom frame and is connected to the first link member and the bucket cylinder, It is equipped with, The first link member and the second link member are, A pair of these are provided on either side of the aforementioned boom frame, The insertion portion through which the pivot shaft of the second link member is inserted is formed to be longer than the width of the boom frame, and is provided to penetrate the side surface of the boom frame and traverse the internal space of the boom frame. The first link member is provided with a recess formed by cutting out the lower end of the first link member so that the first link member does not interfere with the pivot axis of the boom frame. Front loader attitude maintenance mechanism.

2. The first link member is, The following arrangements are positioned so as not to overlap with the boom frame in a plan view: The posture maintenance mechanism for a front loader according to claim 1.

3. The first link member and the second link member are, At least a portion of it is positioned so as to overlap the boom in a side view, regardless of the swing angle of the boom. The posture maintenance mechanism for a front loader according to claim 1 or claim 2.

4. The pair of left and right first link members are, It has bent portions that are curved inward from each other, A posture maintenance mechanism for a front loader according to any one of claims 1 to 3.

5. The aforementioned bent portion is Formed to extend from the pivot axis of the first link member to the connecting portion between the first link member and the second link member, The posture maintenance mechanism for a front loader according to claim 4.

6. The second link member is First component and A second member fixed to one side of the first member, Equipped with, A posture maintenance mechanism for a front loader according to any one of claims 1 to 5.

7. The pivot shaft of the first link member, the connecting portion between the first link member and the second link member, and the connecting portion between the second link member and the bucket cylinder are They are located on approximately the same straight line when viewed from the side. A posture maintenance mechanism for a front loader according to any one of claims 1 to 6.

8. The pair of left and right first link members are, They are formed symmetrically to each other, The pair of left and right second link members are, Formed symmetrically on both sides, A posture maintenance mechanism for a front loader according to any one of claims 1 to 7.

9. A front loader comprising the posture maintenance mechanism described in any one of claims 1 to 8.

10. The pivot axis of the second link member is It is provided so as to cross the internal space of the boom, The front loader according to claim 9.

11. The aforementioned boom and, A pipe section is arranged inside the boom, It is equipped with, The aforementioned boom, A support portion that supports the pivot axis of the second link member, A guide portion is positioned inside the boom, at least in part, to guide the pipe portion so as to avoid the support portion, Equipped with, The front loader according to claim 10.

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