Patent Grant
9970178
The present invention relates to a construction machine including an earth removing implement.
Some construction machines such as hydraulic excavators include an earth removing implement disposed at at least either a front or a rear of a track structure (see, for example, WO 2013/051694). The earth removing implement is utilized to, for example, stop earth and sand such that the earth and sand are not stagnant under a vehicle body during work, in addition to earth removing operations.
The earth removing implement includes a cylinder and a linkage mechanism and is configured so as to be capable of raising and lowering a blade according to use. The earth removing implement is configured such that the blade can be raised to a stowed position away from a ground surface when the earth removing implement is not in use. With the earth removing implement disclosed in WO 2013/051694, in particular, the cylinder and other parts are protected by a sub-cover and a main cover. The sub-cover covers upper sides of the cylinder and other parts. The main cover covers a gap between the sub-cover and the blade. The main cover has a side surface in which a slot that is engaged by a guiding bolt provided in a link is formed. As the blade moves up and down, the slot is guided by the bolt to thereby cause the main cover to tilt in an anterior-posterior direction to change posture, while moving in a vertical direction. More specifically, when the blade is lowered to a ground position at which the blade contacts the ground, the main cover lowers while standing upright to thereby cover a front side of the cylinder and other parts. When the blade is raised up to the stowed position, the main cover goes up to take a lying down posture above the sub-cover and the blade.
In the earth removing implement disclosed in WO 2013/051694, however, the guiding bolt is provided on the link, thereby the bolt goes up with the link when the blade is to be stowed. At this time, the bolt moves upward relative to the slot in the side surface of the main cover. The bolt is positioned at an upper end in the slot when the blade reaches the stowed position. As a result, under a condition in which the blade is raised to be disposed at the stowed position, the slot in the side surface of the main cover extends below the guiding bolt (see FIG. 4 of WO 2013/051694). Thus, the main cover cannot be constrained against a force to raise the main cover by the engagement between the bolt and the slot. Should an external force be applied, therefore, the main cover can be raised. The earth removing implement is also configured such that the main cover lies down by its own weight when the blade is raised to the stowed position. Should a foreign object be wedged in a pivot about which the main cover rotates or should the pivot be deformed, therefore, the main cover may fail to lie flat due to improper pivotal motion of the main cover. Because the main cover is brought close to a swing structure during stowage of the blade, the dislocated main cover may interfere with the swing structure, resulting in a damage to the main cover or the like.
It is an object of the present invention to provide a construction machine including an earth removing implement that can prevent interference with a swing structure.
To achieve the foregoing object, the present invention provides, in one aspect, a construction machine that includes: a track structure; a swing structure provided swingably at an upper portion of the track structure; and an earth removing implement provided at at least either a front portion or a rear portion of the track structure. The earth removing implement includes: a base portion frame mounted on the track structure; a blade mounted on the base portion frame by using a linkage mechanism and a cylinder such that the blade can be raised and lowered; a fixed cover supported on the base portion frame and positioned above the linkage mechanism; a movable cover that covers a gap between the fixed cover and the blade; and a guide pin that guides the movable cover while the blade is being raised and lowered. In the construction machine, the guide pin is supported on the base portion frame; the movable cover includes a main surface portion having a lower end connected rotatably with the blade and having an upper portion leaning on the fixed cover, the movable cover further including a side surface portion having a slot with which the guide pin engages; and the slot is formed along positions of the side surface portion of the movable cover facing the guide pin when the movable cover rotates by having the upper portion of the main surface portion sliding over the fixed cover in accordance with a raising/lowering operation of the blade, the slot being configured such that the guide pin engages with the slot at a lower end position therein when the blade is raised to a highest position.
The present invention can prevent interference with the swing structure.
The embodiment of the present invention will be described below with reference to the accompanying drawings.
1. Construction Machine
The track structure 1 includes wheels 4 with tires. The track structure 1 further includes, though not shown in
The swing structure 2 is connected swingably with an upper portion of the track structure 1 via a swing device 5. A cab 6 is disposed at a front portion of the swing structure 2 on a first side in a lateral direction (left side in the embodiment). An engine, a hydraulic pump, a fuel tank, a hydraulic fluid tank, and various other types of tanks (not shown) are mounted in a rear portion of the cab 6 and are covered in a covering member 7. Additionally, a counterweight 8 is provided at a rear end of the swing structure 2. The counterweight 8 balances weight of the work implement 3 in an entire vehicle body.
The work implement 3 is provided on a second side in the lateral direction (right side in the embodiment) at a front portion of the cab 6. The work implement 3 includes a boom 11, an arm 12, and a bucket 13. Specifically, the boom 11 has a base portion connected with the swing structure 2. The arm 12 has a base portion connected with the boom 11. The bucket 13 is connected with the arm 12.
2. Earth Removing Implement
The earth removing implement 20 is provided at at least either one of the front portion and a rear portion of the track structure 1. Specifically, although
The earth removing implement 20 shown in
The base portion frame 21 serves as a plate with which the earth removing implement 20 can be mounted on an end face facing the anterior-posterior direction, of a frame of the track structure 1. The base portion frame 21 is fixed to the frame of the track structure 1 by, for example, a bolt. The blade 22 has an earth removing face that faces a direction opposite to the track structure 1. With this earth removing face, the blade 22 performs an earth removing operation and stops earth and sand, for example, to prevent the earth and sand from being stagnant under the vehicle body during work. The earth removing face is recessed toward the side of the track structure 1 at a center in the vertical direction and generally stands upright in the vertical direction. The blade 22 extends in the lateral direction in a posture in which the earth removing face faces the direction opposite to the track structure 1 (facing the front for the earth removing implement 20 disposed at the front side). Specifically, the blade 22 has a longitudinal direction that extends in a width direction of the track structure 1.
The linkage mechanism 23 includes brackets 28 and 29, an upper link 31, and a lower link 32. The linkage mechanism 23 thereby connects the blade 22 with the base portion frame 21 such that the blade 22 can be raised and lowered. The bracket 28 is fixed to a front surface (surface on the side opposite to the track structure 1) of the base portion frame 21 in a posture in which the bracket 28 extends vertically. The bracket 29 is fixed to a back surface (surface on the side adjacent to the track structure 1) of the blade 22 in a posture in which the bracket 29 extends vertically. As shown in, for example,
The cylinder 24 has both ends connected with the base portion frame 21 and the linkage mechanisms 23 (the lower links 32 in the present embodiment) via shafts 37 and 38. The shafts 37 and 38 each have a central axis extending laterally. The cylinder 24 extends and contracts to thereby achieve a function of raising and lowering the blade 22 with respect to the base portion frame 21. More specifically, the cylinder 24 includes a tube 41 disposed at a proximal end side thereof and a rod 42. The cylinder 24 has the tube 41 side connected with the base portion frame 21 via the shaft 37 and the bracket 28 at a position higher than the shaft 33. The cylinder 24 has the rod 42 side connected with an intermediate portion of the lower link 32 via the shaft 38. Thus, when the cylinder 24 contracts, the lower links 32 are pulled upward. This causes the linkage mechanisms 23 to rotate upwardly, thus raising the blade 22. When the cylinder 24 extends, the linkage mechanisms 23 rotates downwardly and the blade 22 is thereby lowered.
The guide pin 25 guides the movable cover 27 when the blade 22 is raised and lowered. The guide pin 25 is supported on the base portion frame 21 via a bracket 43. The bracket 43 extends toward the blade 22 and is attached by a plurality of (two in the present embodiment) bolts 45 to the base portion frame 21 (specifically, brackets 44 thereof positioned on the outside in the lateral direction of the brackets 28 of the linkage mechanisms 23). The bracket 43 has through holes (not shown), each having a diameter larger than a thread diameter of the bolts 45 and smaller than a bolt head. The bolts 45 are passed through the through holes and threaded into threaded holes in the bracket 44. This procedure fixes the bracket 43 to the bracket 44.
The fixed cover 26 is a protective member positioned above the linkage mechanisms 23 and the cylinder 24. The fixed cover 26 is fixed to the brackets 28 of the linkage mechanisms 23 via a bracket 46 and supported on the base portion frame 21 via the brackets 28 and 46. The fixed cover 26 includes a top plate portion 47 and side plate portions 48. The top plate portion 47 has a proximal end portion positioned at upper portions of the linkage mechanisms 23, specifically, upper portions of the brackets 28. The top plate portion 47 is inclined downwardly from the proximal end portion toward the blade 22 side, and has a distal end portion bent downwardly (vertically in the present example) via a rounded portion. The side plate portions 48 are disposed on the outside in the lateral direction of the linkage mechanisms 23. The fixed cover 26, being configured as described above, covers upper portions of the cylinder 24 and the right and left linkage mechanisms 23.
Reference is made to
The movable cover 27 is a protective member that covers a gap between the fixed cover 26 and the blade 22. The movable cover 27 includes a main surface portion 51 and side surface portions 52. The main surface portion 51 has a lower end rotatably connected with an upper surface of the blade 22 via bearing stands 53. The main surface portion 51 has an upper portion leaning on to overlap the outer wall surface of the fixed cover 26, so that the main surface portion 51 slides over the outer wall surface of the fixed cover 26 when the blade 22 is raised and lowered. The side surface portions 52 are formed by being bent from both lateral side edges of the main surface portion 51 toward the base portion frame 21 side. The side surface portions 52 each has a slot 54 with which the guide pin 25 engages. The slot 54 is formed to follow along a trajectory described by the guide pin 25 on the side surface portion 52 of the movable cover 27, when the movable cover 27 rotates by having the upper portion of the main surface portion 51 sliding over the seats 49 of the fixed cover 26 in accordance with the raising/lowering operation of the blade 22. Thus, the slot 54 has a shape that is necessarily established under a condition in which the movable cover 27 is displaced to follow the fixed cover 26. In addition, the slot 54 has a length established not to exceed the trajectory of the guide pin 25. The slot 54 is set to have a length such that the guide pin 25 engages with the slot 54 at an upper end position in the slot 54 when the blade 22 is lowered to the lowest position and that the guide pin 25 engages with the slot 54 at a lower end position in the slot 54 when the blade 22 is raised to the stowed position.
Additionally, the movable cover 27 is configured such that, when the guide pin 25 engages with the slot 54, a center of gravity thereof is positioned at all times on the side closer to the base portion frame 21 than to a pivotal point (lower end portion) connected to the blade 22. The movable cover 27 is brought down as the blade 22 is raised. The side surface portion 52 of the movable cover 27 thus has a cutout 55 provided in a lower portion thereof for avoidance of interference with an upper surface rear edge portion of the blade 22 (see
It is noted that the lower guard member 57 is required only to have a cross-sectional shape having slopes extending downwardly toward the front and rear from the apex. Thus, for example, a pipe cut into a semi-circular half may substitute for the angle member.
3. Operation
To perform an earth removing operation or stop earth and sand such that the earth and sand are not stagnant under the vehicle body during such an earth removing operation, the cylinder 24 is extended from the stowed position (see
When the blade 22 is not to be used, the cylinder 24 contracts to thereby raise the blade 22 up to the stowed position (see, for example,
4. Effects
(1) Prevention of Interference of Movable Cover with Swing Structure
As described previously, the guide pins 25 supported on the base portion frame 21 engage with the slots 54 provided in the side surface portions 52 of the movable cover 27. The guide pins 25, because of their being supported on the stationary base portion frame 21, are not displaced even when the blade 22 is raised or lowered. In contrast, the movable cover 27 is raised or lowered with the blade 22, so that the movable cover 27 is also raised when the blade 22 is raised toward the stowed position. As a result, the movable cover 27, and the slots 54 in the side surface portions 52 are raised to face the guide pins 25 and, when the blade 22 reaches the stowed position, the guide pins 25 arrive at the lower ends of the slots 54. Thus, should an external force act to lift the movable cover 27, the engagement between the guide pins 25 and the slots 54 restricts upward movement of the movable cover 27 at the stowed position, so that the movable cover 27 can be prevented from being lifted. Additionally, even when improper pivotal motion occurs in the movable cover 27, the slots 54 are raised to face the guide pins 25 during movement to the stowed position. This motion of the slots 54 forces the movable cover 27 into the lying down posture, so that the movable cover 27 can be smoothly stored in a space between the track structure 1 and the swing structure 2. The prevention of the movable cover 27 from being lifted at the stowed position enables interference between the movable cover 27 and the swing structure 2 to be prevented and damage of, for example, the movable cover 27 to be prevented.
(2) Prevention of Forward Tilt of Movable Cover
The guide pins 25 are disposed at upper positions in the slots 54 at the ground position. Under a condition in which the guide pins 25 are disposed in the slots 54, the center of gravity of the movable cover 27 is disposed at all times on the side closer to the base portion frame 21 than to the lower end portion as the pivotal point. This feature can prevent the movable cover 27 from tilting to the side opposite to the base portion frame 21.
(3) Prevention of Wedging by Pivotal Portion of Movable Cover
The earth removing implement 20 lowered to the ground position is included in a movable range of the bucket 13. The pipe 56 that assumes the pivotal point for the movable cover 27 is, however, disposed at a position retracted from the front edge of the blade 22, so that deformation, for example, caused by interference with the bucket 13 during, for example, a scooping operation can be prevented. Meanwhile, the upper surface of the blade 22 is exposed in areas on the side closer to the work implement 3 with respect to the movable cover 27. As a result, earth and sand tend to be stagnant on the surface of the blade 22 in areas near the lower end portion of the movable cover 27.
The earth removing implement 20 in the present embodiment thus includes the lower guard member 57 provided on the upper surface of the blade 22. The pipe 56 is disposed close to the lower guard member 57 that serves as a gate. The lower guard member 57 stops earth and sand that scatter and fly over to the upper surface of the blade 22. Because the gap between the lower guard member 57 and the pipe 56 is narrow, earth and sand hardly pass therethrough. Should earth and sand be wedged in the gap between the lower guard member 57 and the pipe 56, the area of contact between the wedged earth and sand and the lower guard member 57 is minimal because of the apex of the lower guard member 57 facing the pipe 56. Thus, the wedged earth and sand do not tend to be stagnant in the gap. The wedged earth and sand thus fall down due to, for example, machine vibrations or other external force and fall over the slopes of the lower guard member 57 to be eventually discharged. Should the wedged earth and sand not fall down during operations, an outer peripheral surface of the pipe 56 that is in contact with the wedged earth and sand is opposed to the wedged earth and sand and rotates toward the side opposite to the base portion frame 21 during stowing of the blade 22. Thus, the earth and sand wedged during operations fall down onto the side opposite to the base portion frame 21 while the blade 22 is being stowed. This prevents entry of earth and sand from below the movable cover 27. Together with the prevention of wedging of earth and sand, the foregoing can prevent smooth operation of the movable cover 27 from being degraded.
(4) Assemblability
As described previously, the slot 54 in the movable cover 27 is formed to follow along the trajectory described by the guide pin 25 that faces the movable cover 27 displaced as the blade 22 is raised and lowered. The movable cover 27 is connected rotatably with the blade 22 and displaced to follow the fixed cover 26. As a result, due to deviation in the trajectory of the blade 22 arising from a manufacturing error or assembly error of the linkage mechanism 23 and the blade 22 or from a manufacturing error or assembly error of the fixed cover 26, it is difficult to perfectly match the trajectory described by the guide pin 25 with respect to the movable cover 27 with engineering data. It is not easy to match the slot 54 in the movable cover 27 that makes a combined operation of rotary motion and tilting motion with the trajectory of the guide pin 25. Thus, in the present embodiment, the bracket 43 that supports the guide pin 25 is fixed to the base portion frame 21 by the bolts 45. Because of a difference in diameter existing between the bolt holes provided in the bracket 43 and the bolts, the angle of the bracket 43, or the position of the guide pin 25 can be easily adjusted by simply loosening the bolts 45. Thus, the guide pin 25 can be readily adjusted to the trajectory of the slot 54 being displaced. This achieves assemblability of the earth removing implement 20.
(5) Miscellaneous
The side surface portion 52 of the movable cover 27 normally has the cutout 55 formed therein for avoidance of the interference with the blade 22. Earth and sand that may scatter and fly past the cutout 55 thus can collide with the linkage mechanism 23 and the cylinder 24. In the present embodiment, however, the cutout 55 is covered in the bearing stands 53 that serve as the side surface guard members, so that the linkage mechanism 23 and the cylinder 24 can be reliably protected from the earth and sand that scatter and fly from lateral directions of the movable cover 27. In the present embodiment, in particular, the bearing stands 53 that support the movable cover 27 are configured to serve also as the side surface guard members. This arrangement yields merits, including a reduced number of parts used and a simplified structure. It should, however, be noted that, for the purpose of simply covering the cutout 55, the bearing stands 53 do not necessarily have to serve also as the side surface guard members. Specifically, the earth removing implement 20 may include the side surface guard members separately from the bearing stands.
Although the construction machine to which the earth removing implement 20 is applied is not limited only to the wheel type hydraulic excavator as described previously, the present embodiment has been described for a case in which the earth removing implement 20 is applied to the wheel type hydraulic excavator. With the wheel type hydraulic excavator, it is important to raise the blade 22 to the stowed position close to the swing structure 2 to thereby allow a distance between the blade 22 and the ground surface in order to gain a departure angle. Thus, the earth removing implement 20 that allows the blade to be raised up to the stowed position can be desirably applied to the wheel type hydraulic excavator.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2016-071514 | Mar 2016 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4384620 | Uchida | May 1983 | A |
| 5046565 | Purcell | Sep 1991 | A |
| 20060108309 | Sato | May 2006 | A1 |
| 20140318818 | Nakata | Oct 2014 | A1 |
| Number | Date | Country |
|---|---|---|
| 1922746 | Nov 1969 | DE |
| 2 765 241 | Aug 2014 | EP |
| 10-219732 | Aug 1998 | JP |
| 2010-104302 | May 2010 | JP |
| 2011-157702 | Aug 2011 | JP |
| 10-2010-0101908 | Sep 2010 | KR |
| WO 2013051694 | Apr 2013 | WO |
| Entry |
|---|
| Extended European Search Report issued in counterpart European Application No. 16202573.8 dated Jun. 27, 2017 (Seven (7) pages). |
| Number | Date | Country | |
|---|---|---|---|
| 20170284065 A1 | Oct 2017 | US |
