Work machine

Abstract

Provided is a work machine in which the height of a rear cover can easily be changed.　A work machine (1) comprises: a machine frame (2); a work unit (3) that is supported by the machine frame and performs work on the ground; a rear cover (4) that covers the rear of the work unit and is pivotally supported by the machine frame so as to be vertically swingable; a downward spring device (5) that biases the rear cover in the grounding direction; and a support device (6) that supports the downward spring device with respect to the machine frame. The support device comprises: a first bracket (29) fixedly provided to the machine frame; a second bracket (30) having one side (37) pivotally supported on the first bracket via a pivotally supporting part (43) and having the downward spring device supported on the other side (38) opposite to the one side; and a lock mechanism (53) for locking the swing of the second bracket around the pivotally supporting part (43) at a plurality of positions, the lock mechanism including an operation member (54) to be swingingly operated and a lock member (55) for locking and unlocking by the swinging operation of the operation member.

Description

Work machine

[0001] The present invention relates to a work machine.

[0002] The rotary tiller disclosed in Patent Document 1 includes a tilling part as a working part supported by a machine frame and performing work on the ground. The rear of the tilling part is covered by a rear cover pivotally supported on the machine frame via a support shaft so as to be vertically swingable. The rear cover is urged in the grounding direction by a lowering device.

[0003] Japanese Patent Laid-Open Publication "JP-A-2002-233208"

[0004] By the way, there is a support device that supports a lowering device on a machine frame and can change the height position around the support shaft of a rear cover. However, depending on the structure (holding structure) for holding the height position, it takes time to change the height position around the support shaft of the rear cover. For example, when fastening members such as bolts and nuts are adopted as the holding structure, in order to release and perform the holding by the holding structure, the bolts must be removed or the bolts must be fastened to the nuts, and tools are required.

[0005] In view of the above problems, an object of the present invention is to provide a work machine that can easily change the height of a rear cover.

[0006] A work machine according to an aspect of the present invention includes a machine frame, a working part supported by the machine frame and performing work on the ground, and a rear cover covering the rear of the working part. The rear cover is pivotally supported on the machine frame so as to be vertically swingable, a lowering device that urges the rear cover in the grounding direction, and a support device that supports the lowering device with respect to the machine frame. The support device includes a first bracket fixedly provided on the machine frame, a second bracket pivotally supported on the first bracket via a pivot portion on one side, and the lowering device is supported on the other side opposite to the one side, and a locking mechanism that locks the swinging of the second bracket around the pivot portion at a plurality of positions. The locking mechanism includes an operation member that is swing-operated, and a locking member that releases and performs the locking by the swing operation of the operation member.

[0007] According to the above-described work machine, the locking member is configured to release and lock the swing of the second bracket by the swinging operation of the operating member, so the height of the rear cover can be easily changed.

[0008] This is a side view showing the overall configuration of the work machine. This is a perspective view of the work machine viewed from the rear. This is a perspective view of the support device and projectile release device viewed from the right side. This is a perspective view of the support device and projectile release device viewed from the left side. This is a plan view of the support device and projectile release device. This is an exploded perspective view of the support device. This is an enlarged side view of the main part. This is a plan cross-sectional view of the support device. This is a front cross-sectional view of the support device. This is a cross-sectional view showing the unlocked state of the second bracket. This is a perspective view of the main part according to another embodiment. This is a side view of the main part according to another embodiment. This is a perspective view of the main part according to another embodiment viewed from below. This is a side view of the main part when the rear cover is lifted according to another embodiment. This is a side view of the main part in the state with the rear cover lifted according to another embodiment.

[0009] The following describes one embodiment of the present invention with reference to the drawings as appropriate.

[0010] Figure 1 is a side view showing the overall configuration of the implement 1 according to this embodiment. Figure 2 is a perspective view of the implement 1 from the rear. The implement 1 is a machine that is connected to a movable vehicle and can perform work as the vehicle moves. A tractor can be an example of a vehicle, and the implement 1 is connected to the front or rear of the vehicle, such as a tractor. Hereinafter, the implement 1 of this embodiment will be described using a rotary tiller, which is detachably and vertically adjustable and mounted to the rear of a vehicle such as a tractor via a connecting mechanism such as a three-point linkage mechanism, and tills the field while moving. Note that the implement 1 is not limited to a rotary tiller, and may be other types of implements.

[0011] Furthermore, in this embodiment, the direction of arrow A1 in Figures 1 and 2 is described as the front, the direction of arrow A2 in Figures 1 and 2 is described as the rear, the front side in Figure 1, the direction of arrow B1 in Figure 2 is described as the left, the back side in Figure 1, and the direction of arrow B2 in Figure 2 is described as the right. The horizontal direction, which is perpendicular to the front-rear direction K1, is described as the machine frame width direction K2 (see Figure 2).

[0012] As shown in Figures 1 and 2, the implement 1 comprises a machine frame 2, a working section 3 (tilling section), a rear cover 4, a projectile lowering device 5, and a support device 6. The machine frame 2 is a structure connected to a linking mechanism (three-point linkage mechanism). The working section 3 is supported by the machine frame 2 and can perform work (for example, tilling) on ​​the ground (field). The rear cover 4 is a cover that covers the rear of the working section 3. The rear cover 4 is pivotally supported on the machine frame 2 so as to be able to swing up and down. The projectile lowering device 5 is a device that biases the rear cover 4 toward the ground. The support device 6 is a device that supports the projectile lowering device 5 relative to the machine frame 2.

[0013] As shown in Figures 1 and 2, the machine frame 2 includes a gear case 7, support arms 8L and 8R, a transmission case 9, a side frame 10, an upper cover 11, a frame member 12, and a mast 13. The gear case 7 is located in the center of the machine frame width direction K2.

[0014] Support arm 8L extends to the left from gear case 7, and support arm 8R extends to the right from gear case 7. The upper part of the transmission case 9 is connected to the left end of support arm 8L.

[0015] The side frame 10 is connected at its upper end to the right end of the support arm 8R. The upper cover 11 is positioned below the support arms 8L and 8R. The upper cover 11 is also provided across the space between the transmission case 9 and the upper part of the side frame 10.

[0016] The frame member 12 is positioned behind the upper cover 11. The mast 13 is provided projecting upward from the upper surface of the upper cover 11.

[0017] As shown in Figure 1, the gear case 7 has an input shaft 14 that protrudes forward. Power is transmitted to the input shaft 14 from the tractor's power take-off shaft (PTO shaft) via a joint shaft. The power transmitted to the input shaft 14 is then transmitted to the transmission mechanism in the transmission case 9. Specifically, the power transmitted to the input shaft 14 is transmitted to the transmission mechanism in the transmission case 9 via the transmission mechanism in the gear case 7 and the transmission shaft in the support arm 8L.

[0018] The upper part of the mast 13 has a top link connecting section 15 to which the coupling mechanism (top link of the three-point linkage mechanism) is connected. The front part of the machine frame 2 has a pair of left and right lower link connecting sections 16 to which the coupling mechanism (lower links of the three-point linkage mechanism) is connected.

[0019] The working section 3 is located at the lower part of the machine frame 2. More specifically, the working section 3 has a pivot shaft 17 and a plurality of tilling tines 18. The pivot shaft 17 is located between the transmission case 9 and the lower part of the side frame 10. The pivot shaft 17 has an axis that extends in the machine frame width direction K2. A plurality of tilling tines 18 are attached to the pivot shaft 17 along the machine frame width direction K2. The pivot shaft 17 is supported by the transmission case 9 and the side frame 10 so as to be rotatable around its axis. The pivot shaft 17 rotates due to the power transmitted to the transmission case 9. By rotating the pivot shaft 17 (for example, by rotating in the direction of arrow Y in Figure 1), the tilling tines 18 can till the field (ground). The upper part of the working section 3 is covered by an upper cover 11.

[0020] The rear cover 4 is provided behind the working section 3 (cultivating section), extending from the left end to the right end of the working section 3. The rear cover 4 is pivotally supported at the rear of the machine frame 2. More specifically, a support shaft 19 having an axis extending in the machine frame width direction K2 is provided at the rear of the machine frame 2 (behind the frame member 12). The upper part of the rear cover 4 is supported by the support shaft 19 so as to be rotatable around the axis of the support shaft 19. As a result, the rear cover 4 is able to swing freely in the vertical direction (up and down swinging).

[0021] The soil clumps tilled and thrown backward by the work unit 3 strike the rear cover 4 and are broken up. The lower part of the rear cover 4 has a leveling section 4a that makes contact with the field (ground) and levels the field. A handle member 20 (gripping member) is fixed to the lower rear of the rear cover 4.

[0022] The projectile lowering device 5 biases the rear cover 4 toward the ground using spring force. The projectile lowering device 5 also allows vertical oscillation of the rear cover 4 against the spring force around the pivot shaft 19. As shown in Figure 2, a pair of projectile lowering devices 5 are provided on the left and right sides of the machine frame 2. The projectile lowering devices 5 are located at the rear of the left and right sides of the machine frame 2.

[0023] As shown in Figures 1 to 4, the projectile lowering device 5 includes a rod member 21, biasing members 22A and 22B, and a holder 23. The rod member 21 is formed from a rod. The biasing members 22A and 22B are members that generate a biasing force to bias the rear cover 4 in the vertical direction. For example, the biasing members 22A and 22B are formed from coil springs. The rod member 21 is inserted into the holder 23 so as to be movable in the axial direction.

[0024] Specifically, the rod member 21 is positioned at the rear of the machine frame 2. Furthermore, the rod member 21 is positioned to extend vertically. A fixing member 24 is attached to the upper part of the rod member 21. The fixing member 24 is a member attached to the upper part of the rod member 21.

[0025] The fixing member 24 is, for example, a nut member. The nut member 24 is screwed onto the upper part of the rod member 21. More specifically, a male thread is formed on the upper part of the rod member 21, and the nut member 24 is screwed onto this male thread. A handle member 25 for rotating the nut member 24 is fixed to the nut member 24.

[0026] The lower part of the rod member 21 is pivotally connected to the rear cover 4. For example, the lower part of the rod member 21 is pivotally connected to the lower part of the rear cover 4. More specifically, a mounting piece 26 is fixed to the lower part of the rod member 21. On the other hand, a stay member 27 is fixed to the lower rear part of the rear cover 4. The mounting piece 26 is pivotally connected to the stay member 27. Specifically, the mounting piece 26 can be pivotally connected to the stay member 27 at two positions, upper and lower. A spring receiving member 28 is fixed to the lower part of the rod member 21 (below the holder 23). The spring receiving member 28 is formed, for example, from a washer.

[0027] The biasing members 22A and 22B include the upper biasing member 22A. The upper biasing member 22A is a member that generates a biasing force to bias the rear cover 4 in the opposite direction to the grounding direction. The upper biasing member 22A is externally fitted onto the rod member 21 between the holder 23 and the fixing member (nut member) 24.

[0028] Furthermore, the biasing members 22A and 22B include a downward biasing member 22B. The downward biasing member 22B is a member that generates a biasing force to bias the rear cover 4 toward the ground. The downward biasing member 22B is externally fitted onto the rod member 21 between the holder 23 and the spring receiving member 28.

[0029] The holder 23 is formed in a cylindrical shape with an internal hole that penetrates in the vertical direction. A spring seat is formed on the upper part of the holder 23, against which the upper biasing member 22A abuts. A spring seat is formed on the lower part of the holder 23, against which the lower biasing member 22B abuts.

[0030] The holder 23 has a pair of shaft portions 23a that protrude radially outward. The pair of shaft portions 23a have axes that extend in the machine frame width direction K2. The pair of shaft portions 23a are provided at radially symmetrical positions on the holder 23. As a result, the holder 23 is supported at the rear of the second bracket 30, which will be described later, so as to be rotatable around the axes of the shaft portions 23a.

[0031] As shown in Figure 2, the support device 6 is provided in pairs on the left and right, corresponding to the pair of left and right lowering devices 5. As shown in Figures 1 to 10, the support device 6 has a first bracket 29 and a second bracket 30. For example, the first bracket 29 is made of a plate material. The first bracket 29 is positioned on the upper side of the upper cover 11 such that the plate surface faces the machine frame width direction K2. The first bracket 29 is also fixedly attached to the machine frame 2.

[0032] Specifically, the front part of the first bracket 29 is fixed to a frame material provided at the front of the machine frame 2. The middle and rear parts of the first bracket 29 in the front-rear direction K1 are fixed to the upper surface of the upper cover 11. The second bracket 30 is pivotally supported at the rear of the first bracket 29 so as to be able to swing up and down. The rear part of the first bracket 29 is also designated as the bracket main part 31. The bracket main part 31 is a part that locks the swinging motion of the second bracket 30 so as to be released.

[0033] As shown in Figure 6, the main part of the bracket 31 has an insertion hole 32 and a plurality of locking holes 33. The insertion hole 32 is formed to penetrate through in the width direction K2 of the machine frame. The insertion hole 32 is formed in the lower part of the middle section of the main part of the bracket 31 in the front-rear direction K1.

[0034] The multiple locking holes 33 are formed in a through-shape in the width direction K2 of the machine frame. The multiple locking holes 33 are formed at intervals along an arc line R2 centered on the center line R1 of the insertion hole 32. The multiple locking holes 33 include multiple (three in this embodiment) height adjustment holes 33a, 33b, and 33c formed behind the insertion hole 32, and one inspection hole 33d formed above the insertion hole 32. In the example shown in Figure 6, the distance between the height adjustment holes 33c and the inspection hole 33d is greater than the distance between each of the height adjustment holes 33a, 33b, and 33c. The number of multiple locking holes 33 is not particularly limited.

[0035] As shown in Figure 6, a stopper member 34 is fixed to the main part 31 of the bracket. The stopper member 34 passes through a through hole 35 and is fixed to the main part 31 of the bracket. The through hole 35 is formed below a plurality of height adjustment holes 33a, 33b, and 33c. The through hole 35 is formed to penetrate in the machine frame width direction K2. The stopper member 34 is provided to protrude to the left and right from the main part 31 of the bracket.

[0036] As shown in Figures 3, 4, and 7, an engaging portion 36 is provided projecting upward from the upper part of the middle section of the main bracket portion 31 (above the insertion hole 32).

[0037] As shown in Figures 3 to 5 and Figure 7, the second bracket 30 has one side 37 (front) pivotally supported by the first bracket 29 (bracket main part 31) via a pivot 43, and the reel lowering device 5 is supported on the other side 38 (rear) opposite to the one side 37. For example, the second bracket 30 has a pair of left and right plate members 39. The pair of left and right plate members 39 are formed from long plate material in the front-rear direction K1. The second bracket 30 is constructed by connecting the pair of plate members 39 to each other.

[0038] Each of the pair of plate members 39 has an arm portion 40. The arm portions 40 are positioned to sandwich the first bracket 29. Each of the pair of plate members 39 has a holder support portion 41. The holder support portion 41 is positioned to sandwich the holder 23. Each of the pair of plate members 39 has a connecting portion 42. The connecting portion 42 connects the arm portions 40 and the holder support portion 41 on the same side on the left and right. Therefore, the second bracket 30 has a pair of arm portions 40, a pair of holder support portions 41, and a pair of connecting portions 42.

[0039] As shown in Figures 5 and 8, the pivot portion 43 that pivotally supports the front portion (one side 37) of the second bracket 30 has a collar 44 (cylindrical member), a bolt 45, and a nut 46. The collar 44 is inserted into the insertion hole 32 of the main part 31 of the bracket. The collar 44 is also positioned between a pair of arm portions 40.

[0040] The bolt 45 passes through one (right) arm portion 40R (one plate member 39R), inserts the collar 44 through it, and also passes through the other (left) arm portion 40L (the other plate member 39L). The nut 46 is screwed onto the tip side 45a (opposite the head 45b) of the bolt 45. The axis X1 of the collar 44 and the bolt 45 substantially coincides with the center line R1 of the insertion hole 32.

[0041] Therefore, the multiple locking holes 33 are formed at intervals along an arc line R2 centered on the pivot portion 43. Furthermore, the pair of arm portions 40 are pivotally supported on the first bracket 29 via the pivot portion 43. Specifically, one side 37 of the pair of arm portions 40 (second bracket 30) is pivotally supported on the first bracket 29 via the pivot portion 43 so as to be rotatable about a center line R1 extending in the machine frame width direction K2. As a result, the second bracket 30 is able to swing up and down about the pivot portion 43 (center line R1).

[0042] As shown in Figure 5, the second bracket 30 has a fixing portion 47. The pair of plate members 39 (a pair of arm portions 40) are connected by the fixing portion 47 at the rear of the first bracket 29. The fixing portion 47 is composed of a collar (contact portion) 48 interposed between the pair of arm portions 40, a bolt 49 inserted through one arm portion 40R and the collar 48 and the other arm portion 40L, and a nut 50 screwed onto the tip of the bolt 49. Therefore, the pair of plate members 39 are connected by the pivot portion 43 and the fixing portion 47.

[0043] As shown in Figures 3 to 5, the holder 23 is supported by the holder support portion 41. The holder support portion 41 supports the holder 23 via the shaft portion 23a. In other words, the holder 23 is supported by the holder support portion 41 so as to be rotatable about an axis that extends in the machine frame width direction K2. Therefore, the second bracket 30, the projectile lowering device 5, and the rear cover 4 are able to swing up and down about the pivot portion 43.

[0044] As shown in FIG. 8, the second bracket 30 has a support hole 51. The support hole 51 is formed so as to be communicable with the lock hole 33. The support hole 51 is formed to penetrate in the machine frame width direction K2. Specifically, the support hole 51 is formed to penetrate through one plate member 39R (one arm portion 40R). The relative position between the support hole 51 and each lock hole 33 can be changed by the second bracket 30 swinging around the pivot portion 43. Thereby, when the second bracket 30 swings around the pivot portion 43, the support hole 51 can communicate with any one of the plurality of lock holes 33. Therefore, the support hole 51 can communicate with each lock hole 33 when the second bracket 30 swings around the pivot portion 43.

[0045] As shown in FIGS. 6 to 9, a cylinder portion 52 is fixed to the right surface of one plate member 39R (one arm portion 40R). The cylinder portion 52 is a portion where the inner hole 52a of the cylinder portion 52 communicates with the support hole 51. The right portion of the cylinder portion 52 is cut (see FIG. 8) so that the protruding height of the cylinder portion 52 to the right from one plate member 39 is lower at the rear portion than at the front portion. That is, the right portion of the cylinder portion 52 is inclined so as to become lower as it moves from the front portion to the rear portion.

[0046] The support device 6 has a locking mechanism 53. The locking mechanism 53 can lock the swinging of the second bracket 30 around the pivot portion 43 at a plurality of positions. The locking mechanism 53 has an operating member 54 and a locking member 55. The operating member 54 is a member that can be swing-operated. Further, the locking member 55 releases and locks the second bracket 30 by the swing operation of the operating member 54. Also, as shown in FIGS. 8, 9, etc., the locking mechanism 53 has a guide 56.

[0047] In this embodiment, the lock member 55 is formed by a pin. As shown in FIGS. 8 and 9, the lock member 55 is inserted and supported in the support hole 51 and the inner hole 52a of the cylindrical portion 52 so as to be movable in the axial direction (machine frame width direction K2) and rotatable about the axis. Further, the lock member 55 is movable forward and backward (insertable and removable) with respect to the lock hole 33. Therefore, when the lock member 55 is inserted through the lock hole 33 and the support hole 51, the second bracket 30 is locked. Further, when the lock member 55 is removed from the lock hole 33 (see FIG. 10), the lock of the second bracket 30 is released.

[0048] If only the support hole 51 (only by the plate thickness of the plate member 39) is used to support the lock member 55 movably, it is conceivable that play or the like may occur in the lock member 55. Therefore, in this embodiment, the lock member 55 is supported by the support hole 51 and the cylindrical portion 52. Thereby, the support of the lock member 55 can be surely performed.

[0049] The operation member 54 is formed by an elastic rod member (bar member). As shown in FIG. 8, the operation member 54 has a first rod portion 54a, a second rod portion 54b, and a third rod portion 54c. One end of the first rod portion 54a is connected to the lock member 55. For example, one end of the first rod portion 54a is inserted into a hole formed in the lock member 55 and fixed to the lock member 55 by caulking or the like.

[0050] As shown in FIGS. 8 and 9, the second rod portion 54b is pivotally supported by a pivot support member 57 provided on the other plate member 39L (the other arm portion 40L). Specifically, the pivot support member 57 is formed by a stepped cylindrical body. The pivot support member 57 is a stepped cylindrical body having a small diameter portion 57a and a large diameter portion 57b.

[0051] The other plate member 39L has a retaining hole 58 formed concentrically with the support hole 51. Therefore, the pivot member 57 is provided on the other plate member 39L by inserting the small-diameter portion 57a ​​into the retaining hole 58. The second rod portion 54b has a shaft portion 54ba at one end. The shaft portion 54ba is formed by bending. The second rod portion 54b is pivotally supported on the pivot member 57 so that it can rotate around the pivot axis (oscillation center line) X2, which is the center of the support hole 51 and the retaining hole 58, by inserting this shaft portion 54ba into the inner hole 57c of the pivot member 57.

[0052] The third rod portion 54c connects the other ends of the first rod portion 54a and the second rod portion 54b.

[0053] As shown in Figure 7, the operating member 54 can be swung back and forth around the pivot axis X2. The operating member 54 is also pivotable around the pivot axis X2 between a locked position P1, where the second bracket 30 is locked (see Figure 8), and an unlocked position P2, where the second bracket 30 is unlocked (see Figure 10). Furthermore, in Figure 7, the direction of arrow D1, which swings the operating member 54 from the other side 38 to the one side 37, is the unlocking direction for unlocking the second bracket 30. The direction of arrow D2, which swings the operating member 54 from the one side 37 to the other side 38, is the locking direction for locking the second bracket 30.

[0054] As shown in Figures 3, 5, and 7, the guide 56 in this embodiment is formed from a plate. The guide 56 is fixed to one plate member 39R (one arm portion 40R) with its plate surface facing vertically. More specifically, the guide 56 is positioned on the right side of one plate member 39R (one arm portion 40R) (opposite the side where the main bracket portion 31 is located) and fixed to that right side. The guide 56 is also positioned above the locking member 55. Furthermore, the guide 56 is provided on one arm portion 40R so as to protrude in the protruding direction C1 (to the right, see Figure 5), which is in the machine frame width direction K2 and away from the first bracket 29.

[0055] In this embodiment, the guide 56 is formed separately from one of the plate members 39 and fixed to the plate member 39 by welding or the like. However, the embodiment is not limited to this, and the guide 56 may be integrally molded with the plate member 39 by casting or the like.

[0056] The guide 56 has a guide portion 59 (guide surface). The guide portion 59 guides the operating member 54 so that the locking member 55 moves forward and backward relative to the locking hole 33 by causing the first rod portion 54a to slide against the operating member 54 when the operating member 54 is oscillated (by elastically deforming the first rod portion 54a).

[0057] As shown in Figure 5, the guide portion 59 is formed in an inclined shape. Specifically, the guide portion 59 is formed in an inclined shape that transitions to a protruding direction C1 as it moves from the other side 38 (rear) to the one side 37 (front) (forward). Because the guide portion 59 is formed in an inclined shape, when the first rod portion 54a slides against the guide portion 59, the first rod portion 54a undergoes elastic deformation. Consequently, the locking member 55 moves forward and backward relative to the locking hole 33.

[0058] Furthermore, the guide 56 has a locking portion 60. The locking portion 60 restricts the operating member 54 from swinging from one side 37 to the other side 38 (to the point where the operating member 54 swings so that the locking member 55 is inserted into the locking hole 33) when the locking member 55 is disengaged from the locking hole 33. The locking portion 60 is a protrusion that protrudes in the protruding direction C1 more than the rest of the guide 56.

[0059] The locking mechanism 53 only needs to have at least an operating member 54 and a locking member 55, and it is sufficient that the locking member 55 can lock and release the swinging of the second bracket 30 by the swinging operation of the operating member 54.

[0060] In the above-described locking mechanism 53, when the operating member 54 is in the locked position P1 shown in Figure 7, the locking member 55 is inserted through the support hole 51 and the locking hole 33, as shown in Figures 8 and 9. In other words, the oscillation of the second bracket 30 around the pivot 43 is locked. From this state, when the operating member 54 is swung in the direction of arrow D1 shown in Figure 7, the first rod portion 54a slides against the guide portion 59 of the guide 56. As the first rod portion 54a slides on the guide portion 59 and moves towards one side 37 (forward), the operating member 54 (first rod portion 54a) elastically deforms so that the gap between the first rod portion 54a and the second rod portion 54b widens (the operating member 54 opens), as shown in Figure 10. When the operating member 54 is in the unlocked position P2 shown in Figure 7, the locking member 55 is removed from the locking hole 33, as shown in Figure 10. This releases the lock on the pivot 43 of the second bracket 30, allowing the second bracket 30, the projectile launcher 5, and the rear cover 4 to swing vertically.

[0061] Figures 3, 4, and 7 show the case where the locking member 55 is inserted into the height adjustment hole 33a, which is located at the lower end of the multiple height adjustment holes 33a, 33b, and 33c. When the locking member 55 is inserted into the height adjustment hole 33a at the lower end, the second bracket 30 is in contact with the stopper member 34, and downward swinging is restricted.

[0062] The multiple height adjustment holes 33a, 33b, and 33c are for adjusting the height of the rear cover 4 around the support shaft 19 (height of the leveling section 4a) when the work machine 1 is performing work (plowing). The height adjustment hole 33a at the lower end is for tightening the grip on the tilled soil. The height adjustment hole 33b at the middle is for tightening the grip on the tilled soil less than the height adjustment hole 33a at the lower end. The height adjustment hole 33c at the upper end is for tightening the grip on the tilled soil less than the height adjustment hole 33b at the middle end. The height of the rear cover 4 can be finely adjusted by changing the connection position of the mounting piece 26 to the stay member 27 and by tightening or loosening the nut member 24 of the lowering device 5.

[0063] The inspection hole 33d is for use when performing maintenance (maintenance inspection), such as cleaning the work section 3 or replacing the tilling tines 18. When the second bracket 30 is positioned so that the locking member 55 passes through the inspection hole 33d, the rear cover 4 is lifted up significantly. This opens up the rear of the implement 1, allowing the operator to perform maintenance and inspection from the rear of the implement 1.

[0064] Furthermore, when adjusting the height of the rear cover 4, with the swing lock of the second bracket 30 released (the second bracket 30 in a free state), grasp the handle member 20 and lift the rear cover 4, aligning the support hole 51 with one of the lock holes 33.

[0065] Furthermore, when the locking member 55 is dislodged from the locking hole 33 and the rear cover 4 and the second bracket 30 swing significantly upward, the upper part of the operating member 54 (third rod portion 54c) comes into contact with the engaging portion 36. When the operating member 54 comes into contact with the engaging portion 36, the operating member 54 swings so that the locking member 55 can be inserted into the locking hole 33. Specifically, when the operating member 54 comes into contact with the engaging portion 36, the operating member 54 disengages from the locking portion 60 and swings from one side 37 to the other side 38 (swinging in the locking direction D2), allowing the locking member 55 to be automatically inserted into the locking hole 33.

[0066] Therefore, when inserting the locking member 55 into the inspection hole 33d, the rear cover 4 is lifted with the swing lock of the second bracket 30 released (the locking member 55 removed from the locking hole 33), and the upper part of the operating member 54 is brought into contact with the engaging portion 36. This causes the operating member 54 to swing in the locking direction D2, and the locking member 55 can be automatically inserted into the inspection hole 33d.

[0067] Furthermore, even if the operator uses the implement 1 with the swing lock of the second bracket 30 released, the implement is configured to automatically lock the swing of the second bracket 30 if the rear cover 4 swings significantly. For this reason, if the swing lock of the second bracket 30 is released while driving on roads or fields over rough terrain, the rear cover 4 may swing up and down significantly, potentially causing noise, vibration, and durability issues. In such cases, the function described above, which automatically inserts the lock member 55 into the lock hole 33 when the implement is used with the lock member 55 detached from the lock hole 33, is effective.

[0068] Furthermore, in this embodiment, the rear cover 4 and the second bracket 30 are configured such that the collar 48 (contact portion) contacts the engaging portion 36 when the rear cover 4 swings upward significantly, so as not to lift the rear cover 4 and the second bracket 30 excessively. For this reason, the second bracket 30 has a contact portion 48 that contacts the engaging portion 36 when the rear cover 4 swings upward with the locking member 55 disengaged from the locking hole 33.

[0069] Furthermore, in this embodiment, as shown in Figure 8, the right side of the cylindrical portion 52 is cut diagonally, so that the connection position of the first rod portion 54a to the locking member 55 can be brought closer to one of the plate members 39 while supporting the locking member 55, allowing for a compact configuration and ensuring that the first rod portion 54a slides securely against the guide portion 59.

[0070] Figures 11 to 15 show other embodiments.

[0071] The following describes other embodiments, primarily focusing on the changes from the first embodiment described above. Configurations that are the same as those in the first embodiment are omitted from the illustration and description.

[0072] In this embodiment, as shown in Figure 11, an engaging member 71 is provided on the rear part (bracket main part 31) of the first bracket 29, and an engaging portion 36 is formed on this engaging member 71. The engaging member 71 is made of a plate material and is positioned on the upper part of the front part of the bracket main part 31 (in front of the inspection hole 33d) with the plate surface facing the machine frame width direction K2. In the illustrated example, the engaging member 71 is positioned on the right side of the bracket main part 31.

[0073] As shown in Figures 11 and 12, the engaging member 71 has an upper portion 72, a lower portion 73, and a contact portion 74. The upper portion 72 is formed so that its front-to-back width (width in the front-to-back direction) narrows as it goes upward. The upper part of the upper portion 72 (the upper part of the engaging member 71) is the engaging portion 36.

[0074] The upper portion 72 has an opening 72a formed in a through-shape in the machine frame width direction K2 (the plate thickness direction of the engaging member 71). The lower portion 73 is formed to have approximately the same front-to-back width as the lower end of the upper portion 72. The contact portion 74 is provided towards the rear of the lower end of the lower portion 73.

[0075] As shown in Figure 12, the engaging member 71 is rotatably supported by a pivot shaft 75 at the upper part of the rear of the engaging member 71 (the upper part of the rear of the lower portion 73) on the main bracket portion 31. The pivot shaft 75 has an axis (also called a pivot center) X3 that extends in the machine frame width direction K2. Therefore, the engaging member 71 is rotatable about the pivot center X3.

[0076] Furthermore, an arc-shaped elongated hole (arc hole) 76 is formed in the front part of the main bracket portion 31, centered on the pivot center X3. The contact portion 74 of the engaging member 71 is inserted into this elongated hole 76. In detail, as shown in Figure 13, the contact portion 74 is formed to extend downward from the lower end of the lower portion 73, and then extend to the left so as to be inserted into the elongated hole 76.

[0077] As shown in Figure 12, the engaging member 71 is positioned (held in a predetermined position) with its contact portion 74 in contact with one end (rear end, restricting portion) 76a of the elongated hole 76 in the longitudinal direction. Specifically, the lower portion 73 of the engaging member 71 is heavier than the upper portion 72, and the middle portion of the rear of the engaging member 71 in the vertical direction is supported so as to be rotatable around the pivot center X3. Therefore, a force acts on the engaging member 71 that causes the lower portion 73 to rotate backward (in the direction of arrow D3) around the pivot center X3 due to the weight of the engaging member 71. However, the contact portion 74 in contact with one end 76a of the elongated hole 76 restricts the rotation of the engaging member 71 in the direction of arrow D3, thereby defining the position of the engaging member 71.

[0078] Furthermore, when a force is applied to the engaging member 71 that rotates the engaging member 71 so that the upper portion 72 moves backward (in the direction of arrow D4, see Figure 12) from the state in which the contact portion 74 is in contact with one end 76a of the elongated hole 76, the contact portion 74 moves in the direction toward the other end 76b, which is the end of the elongated hole 76 opposite to the one end 76a (away from the one end 76a), thereby allowing the engaging member 71 to rotate in the direction of arrow D4.

[0079] Furthermore, in this embodiment, as shown in Figure 13, the cylindrical portion 52 is provided with a grease nipple 77 for injecting grease into the interior of the cylindrical portion 52. Correspondingly, the guide 56 has an opening 78 formed through it in the thickness direction to access the grease nipple 77.

[0080] Furthermore, in this embodiment, as shown in Figure 13, the locking portion 60 of the guide 56 (the locking portion 60 that locks the operating member 54 when the operating member 54 is in the unlocked position P2) is formed by cutting out a notch in the plate material constituting the guide 56 (see reference numeral 79 in Figure 13). In addition, the front portion 56a of the guide 56 protrudes in the protruding direction C1 from the locking portion 60, and when the operating member 54 is swung to the unlocked position P2, the first rod portion 54a comes into contact with the front portion 56a of the guide 56, thereby restricting the movement of the operating member 54 (first rod portion 54a) in the unlocked direction D1.

[0081] Furthermore, in this embodiment, as shown in Figure 13, the lower part 52b of the cylindrical portion 52 is cut out. If sand enters the inside of the cylindrical portion 52 (inner hole 52a) and accumulates inside the cylindrical portion 52, the locking member 55 will become difficult to rotate. Therefore, the lower part of the cylindrical portion 52 is cut out to allow the sand to fall out more easily.

[0082] Furthermore, in this embodiment, as shown in Figure 11, a pin insertion hole 81 for inserting a fixing pin 80 is formed above the fixing member (nut member) 24 on the rod member 21. The fixing pin 80 prevents the fixing member 24 from coming out of the rod member 21.

[0083] Next, we will describe the case where the rear cover 4 is lifted high and the locking member 55 is inserted into the inspection hole 33d (when the rear cover 4 is held in a high-lifted position).

[0084] First, the lock on the second bracket 30 is released. Specifically, as shown in Figure 12, the operating member 54 is swung from the locked position P1 to the unlocking direction D1 to the unlocked position P2, and the first rod portion 54a of the operating member 54 is engaged (hooked) with the locking portion 60 of the guide 56 to hold the locking member 55 in a state where it has been removed from the locking hole 33.

[0085] When the rear cover 4 is lifted high in this state, the second bracket 30 swings upward about the center line R1, and the operating member 54 (third rod portion 54c) comes into contact with the engagement portion 36. When the third rod portion 54c comes into contact with the engagement portion 36, the operating member 54 receives a reaction force from the engagement portion 36 (engagement member 71) and swings in the locking direction D2 (see Figure 14). As a result, the first rod portion 54a disengages from the locking portion 60 (the restriction on the swinging of the operating member 54 by the locking portion 60 is released), and the elastic restoring force of the first rod portion 54a causes the first rod portion 54a to slide on the guide portion 59 of the guide 56 in the locking direction D2, and the operating member 54 moves to the locked position P1. This makes it possible to insert the locking member 55 into the lock hole 33 (inspection hole 33d).

[0086] Furthermore, when the second bracket 30 swings upward and the locking member 55 aligns with the inspection hole 33d, the elastic restoring force of the first rod 54a automatically inserts the locking member 55 into the inspection hole 33d, and the second bracket 30 is locked in a state where the rear cover 4 is lifted significantly (the rear cover 4 is held in a significantly lifted position).

[0087] Next, we will describe the case where the rear cover 4 is lowered from a state where it is raised high. Figure 15 shows the state of the second bracket 30 when the rear cover 4 is raised high and the locking member 55 is inserted into the inspection hole 33d. In Figure 15, reference numeral F1 indicates the unlocked position P2 of the operating member 54 when the rear cover 4 is lowered.

[0088] When lowering the rear cover 4 from the state shown in Figure 15, first, the operating member 54, which is in the locked position P1, is moved to the unlocked position P2, and the first rod portion 54a of the operating member 54 is held in a state where it is engaged with the locking portion 60 (the locking member 55 is removed from the inspection hole 33d).

[0089] In this state, the rear cover 4 is lowered. Lowering the rear cover 4 lowers the second bracket 30, and the operating member 54 moves together with the second bracket 30. At this time, the upper part of the engaging member 71 (engaging portion 36) is on the movement path E1, which is the path that the third rod portion 54c of the operating member 54 moves along, so the third rod portion 54c comes into contact with the engaging member 71. When the third rod portion 54c comes into contact with the engaging member 71, the engaging member 71 rotates in the direction of arrow D4, and the engaging member 71 moves away from the movement path E1. As a result, the engaging member 71 does not obstruct the movement of the operating member 54, and the rear cover 4 can be lowered from a greatly raised position. After rotating in the direction of arrow D4, the engaging member 71 returns to its original position (the position where the contact portion 74 is in contact with one end 76a of the elongated hole) due to its own weight.

[0090] As described above, in this embodiment, the operations of holding the rear cover 4 in a greatly raised position and lowering the rear cover 4 from the greatly raised position can be easily performed.

[0091] A preferred embodiment of the present invention provides a work machine 1 as described in the following items.

[0092] (Item 1) A work machine 1 comprising a machine frame 2, a work section 3 supported by the machine frame 2 and used for working on the ground, a rear cover 4 covering the rear of the work section 3, the rear cover 4 being pivotally supported on the machine frame 2 so as to be able to swing up and down, a projectile lowering device 5 that biases the rear cover 4 toward the ground, and a support device 6 that supports the projectile lowering device 5 relative to the machine frame 2, wherein the support device 6 comprises a first bracket 29 fixedly provided on the machine frame 2, a second bracket 30 having one side 37 pivotally supported on the first bracket 29 via a pivot portion 43 and the projectile lowering device 5 supported on the other side 38 opposite to the one side 37, and a locking mechanism 53 that locks the swinging of the second bracket 30 around the pivot portion 43 in multiple positions, the locking mechanism 53 including an operating member 54 that is operated to swing, and a locking member 55 that releases and locks the lock by swinging the operating member 54.

[0093] According to the work machine 1 related to item 1, the locking member 55 is configured to release and lock the swing of the second bracket 30 by the swinging operation of the operating member 54, so that the height of the rear cover 4 can be easily changed.

[0094] (Item 2) The work machine 1 according to Item 1, wherein the first bracket 29 has a plurality of lock holes 33 formed at intervals on an arc line R2 centered on the pivot portion 43, the second bracket 30 has a support hole 51 formed to communicate with the lock holes 33, the lock member 55 locks by being inserted through the lock holes 33 and the support hole 51, and the lock is released by being removed from the lock holes 33, and the lock mechanism 53 has a guide 56 that guides the operating member 54 so that the lock member 55 moves forward and backward relative to the lock holes 33 by swinging the operating member 54.

[0095] According to the work machine 1 related to item 2, a locking mechanism 53 can be constructed with a simple structure. By inserting the locking member 55 through the locking hole 33 and the support hole 51, the swinging of the second bracket 30 can be locked easily and reliably. Furthermore, since the locking member 55 moves forward and backward relative to the locking hole simply by swinging the operating member 54, the burden on the operator can be reduced.

[0096] (Item 3) The work machine 1 according to Item 2, wherein the guide 56 has a locking portion 60 that restricts the swinging of the operating member 54 so that the locking member 55 is inserted into the locking hole 33 when the locking member 55 is dislodged from the locking hole 33.

[0097] According to the work device 1 related to item 3, the operating member 54 can be restricted from swinging to a position that locks the swing of the second bracket 30, regardless of the operator's intention. As a result, the unlocking of the swing of the second bracket 30 is properly maintained, allowing the operator to easily and reliably change the height of the rear cover 4.

[0098] (Item 4) The work machine according to Item 3, which is configured such that when the locking member 55 is dislodged from the locking hole 33 and the second bracket 30 swings upward around the pivot 43, the operating member 54 abuts against an engaging portion 36, and when the operating member 54 abuts against the engaging portion 36, the operating member 54 swings and the restriction on the swing of the operating member 54 by the locking portion 60 is released.

[0099] According to the work machine 1 related to item 4, for example, when the rear cover 4 is lifted high to lock the second bracket 30, the restriction on the swinging of the operating member 54 by the locking part 60 can be released by the action of lifting the rear cover 4.

[0100] (Item 5) The second bracket 30 has a pair of arm portions 40L and 40R that are positioned to sandwich the first bracket 29 and pivotally supported on the first bracket 29 via the pivot portion 43, with the support hole 51 formed in one of the arm portions 40R, and a pivot member 57 provided in the other arm portion 40L at a position corresponding to the support hole 51, and the operating member 54 is formed of a rod material, with one end of the first rod connected to the locking member 55 The work machine 1 according to any one of items 2 to 4, having a section 54a, a second rod section 54b with one end pivotally supported on the pivot member 57, and a third rod section 54c connecting the other ends of the first rod section 54a and the second rod section 54b, wherein the guide 56 has a guide section 59 that guides the first rod section 54a so that the locking member 55 moves forward and backward relative to the locking hole 33 when the first rod section 54a slides against the swinging operation of the operating member 54.

[0101] According to the work machine 1 related to item 5, the support device 6 can be constructed with a simple structure. Furthermore, because the first rod portion 54a and the guide portion 59 move in and out of the lock hole 33 of the lock member 55 due to a relatively simple structure of sliding contact, the maintainability and durability of the lock mechanism 53 can be improved.

[0102] (Item 6) The work machine 1 according to Item 5, wherein the guide portion 59 is formed in an inclined shape, and the first rod portion 54a slides against the guide portion 59, causing the first rod portion 54a to elastically deform, thereby causing the locking member 55 to move forward and backward relative to the locking hole 33.

[0103] According to the work machine 1 related to item 6, a structure for moving the locking member 55 forward and backward relative to the locking hole 33 can be easily constructed. Furthermore, as the operating member 54 is oscillated, the first rod portion 54a (operating member 54) elastically deforms, causing the locking member 55 to move forward and backward relative to the locking hole 33. This prevents the operating member 54 from being easily oscillated by vibrations, etc., and prevents the locking and unlocking from being switched unintentionally by the operator.

[0104] (Item 7) The work machine 1 according to Item 6, wherein the guide 56 is provided on the one arm portion 40R so as to protrude in a protruding direction C1 which is away from the first bracket 29, the guide portion 59 is inclined so as to move from the other side 38 toward the one side 37 toward the protruding direction C1, and the first rod portion 54a is elastically deformed so that the locking member 55 can be dislodged from the locking hole 33 by swinging the operating member 54 toward the other side 38 toward the one side 37.

[0105] According to the work machine 1 related to item 7, a locking mechanism 53 can be constructed with a simple structure. In particular, when the locking member 55 is removed from the locking hole 33 to release the lock, a biasing force acts on the first rod portion 54a in the opposite direction to the protruding direction C1 due to elastic deformation. Therefore, if the operator interrupts the swinging operation of the operating member 54 with the guide portion 59, the operating member 54 is swung by this biasing force in the direction from one side 37 to the other side 38. As a result, even if the operating member 54 is swung by vibration or the like, it is possible to prevent it from being released unintentionally by the operator.

[0106] (Item 8) The work machine 1 according to Item 3, wherein the second bracket 30 has a contact portion 48 that contacts the engaging portion 36 when the rear cover 4 swings upward while the locking member 55 is dislodged from the locking hole 33.

[0107] According to the work machine 1 related to item 8, the rear cover 4 can be prevented from being lifted excessively by a relatively simple structure.

[0108] (Item 9) The work machine 1 according to claim 5, wherein one of the arm portions 40R is a cylindrical portion 52 whose inner hole 52a communicates with the support hole 51, and which has a cylindrical portion 52 that supports the locking member 55.

[0109] According to the work machine 1 related to item 9, the support of the locking member 55 can be made more secure.

[0110] Having described the present invention above, the embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than the foregoing description, and all modifications within the meaning and scope of equivalents of the claims are intended to be included.

[0111] 1: Working machine 2: Machine frame 3: Working section 4: Rear cover 5: Bullet lowering device 6: Support device 29: First bracket 30: Second bracket 33: Locking hole 36: Engaging part 37: One side 38: Other side 40L: One arm section 40R: The other arm section 43: Pivot section 48: Contact section 51: Support hole 52: Cylinder section 52a: Inner hole 53: Locking mechanism 54: Operating member 54a: First rod section 54b: Second rod section 54c: Third rod section 55: Locking member 56: Guide 57: Pivot member 59: Guide section 60: Locking section C1: Protruding direction R2: Arc line

Claims

1. A work machine comprising: a machine frame; a work section supported by the machine frame for performing work on the ground; a rear cover covering the rear of the work section, the rear cover being pivotally supported on the machine frame so as to be able to swing up and down; a projectile lowering device for biasing the rear cover toward the ground; and a support device for supporting the projectile lowering device relative to the machine frame, wherein the support device comprises: a first bracket fixedly provided on the machine frame; a second bracket, one side of which is pivotally supported on the first bracket via a pivot, and the projectile lowering device being supported on the other side opposite to the first side; and a locking mechanism for locking the swinging of the second bracket around the pivot at multiple positions, the locking mechanism including an operating member that is operated to swing, and a locking member that releases and locks the lock by swinging the operating member.

2. The work machine according to claim 1, wherein the first bracket has a plurality of locking holes formed at intervals on an arc line centered on the pivot portion, the second bracket has a support hole formed to communicate with the locking holes, the locking member locks by being inserted through the locking holes and the support hole, and the lock is released by being removed from the locking holes, and the locking mechanism has a guide that guides the operating member so that the locking member moves forward and backward relative to the locking holes by swinging the operating member.

3. The work machine according to claim 2, wherein the guide has a locking portion that restricts the swinging of the operating member so that the locking member is inserted into the locking hole when the locking member is dislodged from the locking hole.

4. The work machine according to claim 3, which is provided with an engagement portion that the operating member contacts when the second bracket swings upward around the pivot portion while the locking member is dislodged from the locking hole, and is configured such that when the operating member contacts the engagement portion, the operating member swings and the restriction on the swinging of the operating member by the locking portion is released.

5. The work machine according to claim 2 or 3, wherein the second bracket has a pair of arm portions arranged to sandwich the first bracket and pivotally supported to the first bracket via the pivot portion, the support hole is formed in one of the arm portions, and a pivot member is provided in the other arm portion at a position corresponding to the support hole, the operating member is formed of a rod and has a first rod portion with one end connected to the locking member, a second rod portion with one end pivotally supported to the pivot member, and a third rod portion connecting the other ends of the first rod portion and the second rod portion, and the guide has a guide portion that guides the first rod portion so that the locking member moves forward and backward relative to the locking hole by the swinging operation of the operating member.

6. The work machine according to claim 5, wherein the guide portion is formed in an inclined shape, and the first rod portion slides against the guide portion, causing the first rod portion to elastically deform, thereby causing the locking member to move forward and backward relative to the locking hole.

7. The work machine according to claim 6, wherein the guide is provided on one arm portion so as to protrude in a direction away from the first bracket, the guide portion is inclined to transition to the protruding direction as it moves from the other side toward the one side, and the first rod portion is elastically deformed so that the locking member can be dislodged from the locking hole by swinging the operating member toward the one side.

8. The work machine according to claim 3, wherein the second bracket has a contact portion that contacts the engaging portion when the rear cover swings upward while the locking member is dislodged from the locking hole.

9. The work machine according to claim 5, wherein one of the arm portions is a cylindrical portion whose inner bore communicates with the support hole and has a cylindrical portion that supports the locking member.

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