JP7514202B2 - Construction Machinery - Google Patents

Description

This disclosure relates to construction machines, such as hydraulic excavators, and in particular to construction machines equipped with soil removal devices.

A hydraulic excavator, a typical example of construction machinery, is equipped with a self-propelled lower traveling body, an upper rotating body that is mounted on the lower traveling body so that it can rotate via a rotating device, and a working device provided in front of the upper rotating body. In small hydraulic excavators, a soil removal device is provided on the truck frame that constitutes the lower traveling body, and this soil removal device is used to perform work such as leveling the ground.

The soil removal device is comprised of an arm whose base end is rotatably attached to the truck frame using a pin, a blade attached to the tip end of the arm, and a blade lifting cylinder whose base end is rotatably attached to the truck frame and whose tip end is rotatably attached to the arm. Therefore, by raising and lowering the blade in response to the extension and retraction of the blade lifting cylinder, it is possible to perform leveling work, soil removal work, etc. (see Patent Document 1).

JP 2013-238107 A

The blade of the soil removal device is attached to the truck frame via an arm, and extends left and right (in the vehicle width direction of the hydraulic excavator) while protruding forward from the lower traveling body. For this reason, when performing leveling work in narrow spaces such as residential areas and urban areas in urban areas, there is a possibility that the end of the blade will interfere with obstacles around the work site, such as guardrails and standing trees, when the hydraulic excavator swings around the narrow work site. As a result, there is a problem in that the travelability (mobility) of the hydraulic excavator is reduced when performing leveling work in a narrow work site.

In particular, in soil removal devices equipped with angle cylinders, both ends of the blade in the longitudinal direction swing back and forth (angle movement) in response to the extension and contraction of the angle cylinder. For this reason, it is necessary to prevent interference between the shoe of the lower running body and the longitudinal end of the blade when the blade performs an angle movement. As a result, in hydraulic excavators equipped with soil removal devices equipped with angle cylinders, the blade is set to protrude further from the lower running body, which increases the possibility that the end of the blade will interfere with surrounding obstacles during turning.

The object of the present invention is to provide a construction machine that is equipped with an earth removal device and can ensure good drivability at each work site.

The present invention is a construction machine having a self-propelled vehicle body and an earth removal device provided on the vehicle body, the earth removal device comprising an arm whose base end is rotatably attached to a blade support member provided on the vehicle body using a pin, a blade attached to the tip end of the arm, and a blade lifting cylinder whose base end is rotatably attached to a cylinder support member provided on the vehicle body and whose tip end is rotatably attached to the arm, and which raises and lowers the blade relative to the blade support member in response to telescopic movement, characterized in that either one of the pin hole provided in the blade support member through which the pin is inserted and the pin hole provided on the base end of the arm is formed as a long slot into which the pin engages so as to be movable in the fore-and-aft direction of the vehicle body, and the blade is provided so as to be movable between a protruding position in which the pin protrudes in a direction away from the blade support member and a retracted position in which the blade is retracted toward the blade support member by the pin moving in the fore-and-aft direction of the vehicle body along the long slot.

According to the present invention, the blade can be moved from the extended position to the retracted position by moving the pin connecting the base end of the arm and the blade support member along a long groove formed in either the blade support member or the arm. This reduces the length of the blade that extends from the vehicle body, preventing the blade from interfering with surrounding obstacles when the vehicle body is turning, ensuring good driving performance.

FIG. 1 is a left side view showing a hydraulic excavator as a construction machine according to an embodiment of the present invention. FIG. 2 is a plan view of the hydraulic excavator with the upper rotating body removed, showing the lower traveling body, the soil removal device, etc., as viewed from above. FIG. 4 is a perspective view showing a lower traveling body with the soil removal device removed. FIG. 2 is a perspective view showing main parts of a truck frame of a lower traveling body, an earth removal device, etc. 3 is a cross-sectional view of the blade support member, the cylinder support member, the long groove hole, the soil removal device, etc., as viewed from the direction of the arrows VV in FIG. 2. 6 is a cross-sectional view taken from a position similar to that of FIG. 5, illustrating a state in which the blade lifting cylinder is extended while the blade is held in the extended position. FIG. 6 is a cross-sectional view taken from a position similar to that of FIG. 5, illustrating a state in which the blade has been moved to a retracted position. FIG. 6 is a cross-sectional view taken in a similar position to FIG. 5 and showing a second long groove according to a comparative example. FIG. 6 is a cross-sectional view of a modified earth removal device taken from a position similar to that of FIG. 5 .

The following describes in detail an embodiment of a construction machine according to the present invention as applied to a hydraulic excavator, with reference to the accompanying drawings. In the embodiment, the travel direction of the hydraulic excavator is defined as the front-rear direction, and the direction perpendicular to the travel direction is defined as the left-right direction.

A hydraulic excavator 1, a representative example of a construction machine, comprises a self-propelled crawler-type lower running body 2 and an upper rotating body 4 rotatably mounted on the lower running body 2 via a slewing wheel 3, and the lower running body 2 and upper rotating body 4 form the body of the hydraulic excavator 1. A swing-type working device 5 for performing work such as excavating earth and sand is provided in front of the upper rotating body 4. A soil removal device 12 for performing work such as ground leveling is provided in front of the lower running body 2.

The lower running body 2 is equipped with a track frame 6 that serves as a base. As shown in Figures 2 and 3, the track frame 6 is composed of a center frame 6A located in the center in the left-right direction, a left side frame 6B and a right side frame 6C arranged on either side of the center frame 6A, front and rear left legs 6D that connect the center frame 6A and the left side frame 6B, and front and rear right legs 6E that connect the center frame 6A and the right side frame 6C.

A large-diameter annular cylindrical body 6F is provided on the upper surface side of the center frame 6A. A slewing ring 3 is attached to the cylindrical body 6F, and an upper slewing body 4 is attached to the slewing ring 3, so that the upper slewing body 4 is supported so as to be rotatable relative to the lower running body 2. On the front side of the center frame 6A, a cylinder support member 24 (described below) is located in the center in the left-right direction, and a left blade support member 20 and a right blade support member 21 (described below) are located on both the left and right sides of the cylinder support member 24.

The left side frame 6B and the right side frame 6C each have a drive wheel 7A at their rear end and an idler wheel 7B at their front end. A track (crawler) 8 is wound around the drive wheel 7A and the idler wheel 7B on the left side frame 6B and the right side frame.

The upper rotating body 4 has a rotating frame 9 as a base, and the rotating frame 9 is attached to the lower traveling body 2 via a rotating ring 3 so that it can rotate. A swing post 5A of the working device 5 is attached to the front side of the rotating frame 9. A counterweight 10 that maintains the weight balance with the working device 5 is attached to the rear side of the rotating frame 9. An engine (neither shown) that drives a hydraulic pump is provided in front of the counterweight 10, and hydraulic oil discharged from the hydraulic pump is supplied to various hydraulic actuators mounted on the hydraulic excavator 1. A cab 11 is provided in front of the counterweight 10, and inside the cab 11, a driver's seat, a travel lever/pedal device, a working lever device, a blade operating device, etc. (none shown) are arranged.

The working device 5 is configured with a swing post 5A attached to the front side of the revolving frame 9, a boom 5B attached to the swing post 5A, an arm 5C attached to the tip of the boom 5B, a bucket 5D attached to the tip of the arm 5C, a boom cylinder 5E, an arm cylinder 5F, and a bucket cylinder 5G. In addition, a swing cylinder (not shown) is provided between the revolving frame 9 and the swing post 5A to swing the swing post 5A left and right.

Next, we will explain the soil removal device 12 installed on the lower running body 2.

The soil removal device 12 is mounted on the truck frame 6 of the lower traveling body 2 and performs tasks such as leveling the ground and removing soil. The soil removal device 12 includes an arm 13, a blade 16, a blade lifting cylinder 17, and an angle cylinder 19.

The arm 13 of the soil removal device 12 is formed in a V-shape that branches left and right from the tip side (blade 16 side) to the base side (truck frame 6 side), and has a left arm section 13A and a right arm section 13B. A pin hole 13A2 is provided on the base side 13A1 of the left arm section 13A, and the axial middle part of the pin 14 is attached to the pin hole 13A2. Both axial sides of the pin 14 protrude from the left arm section 13A and are inserted into the left blade support member 20. Similarly, a pin hole (not shown) is provided on the base side 13B1 of the right arm section 13B, and the axial middle part of the pin 14 is attached to this pin hole. Both axial sides of the pin 14 protrude from the right arm section 13B and are inserted into the right blade support member 21.

The tips of the left arm section 13A and the right arm section 13B are connected by a connecting member 13C extending in the left-right direction. A cylinder bracket 13D is provided in the middle of the connecting member 13C, and the tip 17B of a blade lifting cylinder 17 is attached to the cylinder bracket 13D. A blade 16 is attached to the tip 13E of the arm 13, which is forward of the connecting member 13C, via a swivel pin 15 extending in the up-down direction. An arm-side cylinder bracket 13F is provided in the middle of the left arm section 13A in the front-to-rear direction, and one end of an angle cylinder 19 is attached to this arm-side cylinder bracket 13F.

The blade 16 is attached to the tip 13E of the arm 13. The blade 16 is a rectangular plate extending in the left-right direction, and the center of the rear side of the blade 16 is attached to the tip 13E of the arm 13 via a swivel pin 15. A blade side cylinder bracket 16A is provided on the rear side of the blade 16, spaced to the left of the attachment part (swivel pin 15) to the arm 13.

The blade lift cylinder 17 is provided between the truck frame 6 and the arm 13. Specifically, the base end 17A of the blade lift cylinder 17 is rotatably attached to the cylinder support member 24 via the second pin 18, and the tip end 17B of the blade lift cylinder 17 is rotatably pin-connected to the cylinder bracket 13D of the arm 13. The blade lift cylinder 17 rotates the arm 13 up and down about the pin 14 in response to the extension and retraction operation, thereby raising and lowering the blade 16 attached to the tip end 13E of the arm 13 relative to the left blade support member 20 and the right blade support member 21. Therefore, by lowering the blade 16 while the hydraulic excavator 1 is traveling, soil can be pushed in the traveling direction to perform leveling work, soil removal work, etc.

The angle cylinder 19 is provided between the arm 13 and the blade 16. Specifically, one end of the angle cylinder 19 is rotatably attached to the arm side cylinder bracket 13F of the left arm section 13A, and the other end of the angle cylinder 19 is rotatably attached to the blade side cylinder bracket 16A of the blade 16. The angle cylinder 19 swings both ends of the length of the blade 16 back and forth (angles) around the swivel pin 15 in response to the extension and retraction movement. This allows the soil and sand pushed out by the blade 16 to be discharged all at once to the left or right side of the lower traveling body 2.

The left blade support member 20 is provided on the front left side of the center frame 6A, as shown in Figures 3 to 5. The left blade support member 20 is made up of two plate-shaped bodies that face each other in the left-right direction with a certain gap between them, and protrudes forward from the center frame 6A. The left blade support member 20 supports the base end side 13A1 of the left arm portion 13A that constitutes the arm 13 via a pin 14.

The right blade support member 21 is provided on the front right side of the center frame 6A, and is positioned symmetrically to the left and right side of the left blade support member 20. The right blade support member 21 has the same shape as the left blade support member 20. In other words, the right blade support member 21 is made up of two plate-like bodies that face each other in the left and right direction with a certain gap between them, and protrudes forward from the center frame 6A. The right blade support member 21 supports the base end side 13B1 of the right arm portion 13B that constitutes the arm 13 via the pin 14.

The long slots 22 are provided in the left blade support member 20 and the right blade support member 21, respectively, and form pin holes through which the pins 14 are inserted. The long slots 22 penetrate the left blade support member 20 and the right blade support member 21 in the plate thickness direction, and are formed as arc-shaped long slots extending in the front-rear direction. The front end of the long slot 22 is the protruding end 22A, and the rear end of the long slot 22 is the retracting end 22B. The long slot 22 is inclined obliquely upward from the protruding end 22A toward the retracting end 22B.

Both ends of the pin 14 attached to the base end side 13A1 of the left arm section 13A are inserted into a long slot 22 formed in the left blade support member 20. Therefore, the left arm section 13A is movable in the fore-and-aft direction of the vehicle body between the protruding end 22A and the retracting end 22B of the long slot 22. Both ends of the pin 14 attached to the base end side 13B1 of the right arm section 13B are inserted into a long slot 22 formed in the right blade support member 21. Therefore, the right arm section 13B is also movable in the fore-and-aft direction of the vehicle body between the protruding end 22A and the retracting end 22B of the long slot 22.

That is, as shown in FIG. 5, when the pin 14 attached to the left arm portion 13A and the pin 14 attached to the right arm portion 13B engage with the protruding end portion 22A of the long slot 22, the blade 16 attached to the tip 13E of the arm 13 is positioned in the protruding position. In this protruding position, the blade 16 protrudes away from the left blade support member 20 and the right blade support member 21, and the blade 16 is separated from the left blade support member 20 and the right blade support member 21 by a distance A. When the blade 16 is in the protruding position, even if the blade 16 is angled by the angle cylinder 19, the end of the blade 16 does not interfere with the crawler belt 8 of the undercarriage 2, and ground leveling work can be performed smoothly.

On the other hand, as shown in FIG. 7, when the pin 14 attached to the left arm portion 13A and the pin 14 attached to the right arm portion 13B engage with the retracted end 22B of the long slot 22, the blade 16 attached to the tip 13E of the arm 13 is positioned in the retracted position. In this retracted position, the blade 16 is retracted toward the left blade support member 20 and the right blade support member 21, and the distance B between the blade 16 and the left blade support member 20 and the right blade support member 21 is smaller than the distance A in the extended position (B<A). With the blade 16 in the retracted position, the blade 16 can be prevented from interfering with surrounding obstacles when the hydraulic excavator 1 is turning, improving maneuverability in narrow work sites.

In the left blade support member 20, a plurality of (e.g., two) protruding side bolt holes 20A are screwed around the protruding side end 22A of the long slot 22, and a plurality of (e.g., two) retracting side bolt holes 20B are screwed around the retracting side end 22B of the long slot 22. In the right blade support member 21, a plurality of protruding side bolt holes (not shown) are screwed around the protruding side end 22A of the long slot 22, similar to the left blade support member 20, and a plurality of retracting side bolt holes (not shown) are screwed around the retracting side end 22B of the long slot 22, similar to the left blade support member 20.

The blade stopper 23 is provided on the left blade support member 20 and the right blade support member 21. The blade stopper 23 is formed of an arc-shaped plate and is detachably attached to the left blade support member 20 and the right blade support member 21 using two bolts 23A. As shown in FIG. 5, when the pin 14 of the left arm portion 13A engages with the protruding end 22A of the long slot 22 and the blade 16 moves to the protruding position, the blade stopper 23 is fixed to the left blade support member 20 so as to close the long slot 22 by the bolt 23A screwed into the protruding bolt hole 20A of the left blade support member 20. Similarly, the blade stopper 23 is fixed to the right blade support member 21 so as to close the long slot 22. As a result, the pin 14 is fixed to the protruding end 22A of the long slot 22, and the blade 16 can be held in the protruding position.

On the other hand, as shown in FIG. 7, when the pin 14 of the left arm portion 13A engages with the retraction side end 22B of the long slot 22 and the blade 16 moves to the retracted position, the blade stopper 23 is fixed to the left blade support member 20 so as to block the long slot 22 by a bolt 23A that screws into the retraction side bolt hole 20B of the left blade support member 20. Similarly, the blade stopper 23 is fixed to the right blade support member 21 so as to block the long slot 22. As a result, the pin 14 is fixed to the retraction side end 22B of the long slot 22, and the blade 16 can be held in the retracted position.

The cylinder support member 24 is located between the left blade support member 20 and the right blade support member 21 and is provided at the front center of the center frame 6A. The cylinder support member 24 is made of two plate-shaped bodies that face each other in the left-right direction with a certain gap between them, and protrudes forward from the center frame 6A. The cylinder support member 24 supports the base end 17A of the blade lifting cylinder 17 via the second pin 18.

The second long slot 25 is provided in the cylinder support member 24 and constitutes a pin hole through which the second pin 18 is inserted. The second long slot 25 penetrates the cylinder support member 24 in the plate thickness direction and is formed as a long slot extending diagonally downward from the front end side to the rear end side. The front end of the second long slot 25 is the protruding side end 25A, and the rear end of the second long slot 25 is the retracting side end 25B.

That is, the second long slot 25 is formed as an arc-shaped long slot that extends continuously diagonally downward from the protruding end 25A to the retracting end 25B. Therefore, as shown in Figures 5 and 6, the distance C from the pin connection 26 between the tip 17B of the blade lifting cylinder 17 and the arm 13 (cylinder bracket 13D) to the second pin 18 increases continuously (gradually) as the second pin 18 moves from the protruding end 25A of the second long slot 25 to the retracting end 25B.

The second pin 18 attached to the base end 17A of the blade lift cylinder 17 has both ends inserted into the second long slot 25 formed in the cylinder support member 24. As a result, the base end 17A of the blade lift cylinder 17 is supported by the cylinder support member 24 via the second pin 18 and is movable between the protruding end 25A and the retracting end 25B of the second long slot 25. In the cylinder support member 24, a plurality of (e.g., two) protruding side bolt holes 24A are screwed around the protruding end 25A of the second long slot 25, and a plurality of (e.g., two) retracting side bolt holes 24B are screwed around the retracting end 25B of the second long slot 25.

The cylinder stopper 27 is provided on the cylinder support member 24. The cylinder stopper 27 is formed of an arc-shaped plate and is detachably attached to the cylinder support member 24 using two bolts 27A. As shown in FIG. 5, when the second pin 18 engages with the protruding end 25A of the second long slot 25, the cylinder stopper 27 is fixed to the cylinder support member 24 by the bolt 27A that screws into the protruding bolt hole 24A of the cylinder support member 24. As a result, the second long slot 25 is blocked by the cylinder stopper 27, and the base end 17A side of the blade lift cylinder 17 is held in the protruding position for setting the blade 16 in the protruding position.

On the other hand, as shown in FIG. 6, when the second pin 18 engages with the retraction side end 25B of the second long slot 25, the cylinder stopper 27 is fixed to the cylinder support member 24 by the bolt 27A that screws into the retraction side bolt hole 24B of the cylinder support member 24. As a result, the second long slot 25 is blocked by the cylinder stopper 27, and the base end 17A side of the blade lift cylinder 17 is held in a retraction preparation position for moving the blade 16 to the retraction position.

The hydraulic excavator 1 according to this embodiment is equipped with the soil removal device 12 as described above, and the operation of the hydraulic excavator 1 will be described below.

First, when performing leveling work on a relatively large work site, the blade 16 is held in the protruding position shown in Figure 5. In this case, the pins 14 attached to the left arm portion 13A and the right arm portion 13B of the arm 13 are fixed in a position where they engage with the protruding end portion 22A of the long slot 22 using the blade stopper 23. In addition, the second pin 18 attached to the blade lift cylinder 17 is fixed in a position where it engages with the protruding end portion 25A of the second long slot 25 using the cylinder stopper 27.

In this state, the operator gets into the cab 11 and operates the travel lever/pedal device (not shown) to travel the lower traveling body 2 and self-propel the hydraulic excavator 1 to the desired work site. When the hydraulic excavator 1 moves to the work site, the operator operates the operating lever device (not shown). This allows the upper rotating body 4 to rotate while the working device 5 is used to perform work such as excavating soil. The operator also operates the blade operating device (not shown) to ground the blade 16 on the ground and travels the lower traveling body 2 in this state. This allows the blade 16 to be used to perform leveling work at the work site.

In this case, the blade 16 is positioned in the protruding position, so a large gap A can be secured between the blade 16 and the left blade support member 20. Therefore, even if the blade 16 is angled by the angle cylinder 19 during ground leveling work, the end of the blade 16 does not interfere with the tracks 8 of the undercarriage 2, and ground leveling work can be performed smoothly.

On the other hand, when working in a narrow work site such as an urban area, if the hydraulic excavator 1 rotates with the blade 16 held in the extended position, the end of the blade 16 may interfere with surrounding obstacles. For this reason, in a narrow work site, the blade 16 is moved from the extended position shown in FIG. 5 to the retracted position shown in FIG. 7.

In this case, as shown in FIG. 6, the cylinder stopper 27 is removed from the cylinder support member 24 to allow the second pin 18 to move. In this state, by extending the blade lift cylinder 17, the second pin 18 moves from the protruding end 25A of the second long slot 25 and engages with the retracting end 25B. Then, by attaching the cylinder stopper 27 to the cylinder support member 24, the second pin 18 is fixed in a position where it engages with the retracting end 25B of the second long slot 25. This positions the base end 17A of the blade lift cylinder 17 in the retraction preparation position.

Next, as shown in FIG. 7, the blade stopper 23 is removed from the left blade support member 20 and the right blade support member 21, allowing the pin 14 of the left arm portion 13A and the right arm portion 13B to move. Then, by contracting the blade lift cylinder 17, the pin 14 moves from the protruding end 22A of the long slot 22 and engages with the retracted end 22B. In this state, the blade stopper 23 is attached to the left blade support member 20 and the right blade support member 21. As a result, the pin 14 is fixed in the position where it engages with the retracted end 22B of the long slot 22, allowing the blade 16 to be moved to the retracted position.

In this way, by moving the blade 16 from the extended position to the retracted position, the distance B between the blade 16 and the left blade support member 20 can be made smaller than the distance A in the extended position. As a result, when the blade 16 is positioned in the retracted position, it is possible to prevent the end of the blade 16 from interfering with surrounding obstacles when the hydraulic excavator 1 is turning, thereby improving maneuverability in narrow work sites.

In this embodiment, a second long slot 25 is formed in the cylinder support member 24, and a second pin 18 attached to the base end 17A of the blade lift cylinder 17 is movable along the second long slot 25 in the front-rear direction of the vehicle body. As a result, when the blade 16 is moved from the extended position to the retracted position, the blade lift cylinder 17 is extended and its base end 17A is moved to the retraction preparation position, so that the stroke S (see FIG. 6) when the blade lift cylinder 17 is retracted can be increased. As a result, the blade 16 can be retracted significantly toward the left blade support member 20 and the right blade support member 21, further improving the drivability of the hydraulic excavator 1 in a narrow work site.

In this embodiment, the second long slot 25 of the cylinder support member 24 is formed as an arc-shaped long slot extending obliquely downward from the protruding end 25A to the retracting end 25B. Therefore, the distance C from the pin connection portion 26 between the tip 17B of the blade lift cylinder 17 and the arm 13 to the second pin 18 increases continuously (gradually) as the second pin 18 moves from the protruding end 25A of the second long slot 25 to the retracting end 25B. Therefore, when the cylinder stopper 27 is removed from the cylinder support member 24 and the blade lift cylinder 17 is extended to move the base end 17A side of the blade lift cylinder 17 from the protruding position (position in FIG. 5) to the retraction preparation position (position in FIG. 6), the second pin 18 always abuts against the periphery of the second long slot 25. As a result, while the blade lift cylinder 17 is being extended, the load on the base end 17A side of the blade lift cylinder 17 can always be supported by the cylinder support member 24, preventing the base end 17A of the blade lift cylinder 17 from falling due to its own weight.

Here, the reason why in this embodiment, the distance C from the pin connection 26 between the tip 17B of the blade lifting cylinder 17 and the arm 13 to the second pin 18 is configured to continuously increase as the second pin 18 moves from the protruding end 25A of the second long slot 25 to the retracting end 25B will be explained based on a comparison with the comparative example shown in Figure 8.

Figure 8 shows the second long slot 101 according to the comparative example. In this comparative example, the same components as those in this embodiment are given the same reference numerals. The second long slot 101 according to the comparative example, like the second long slot 25 according to this embodiment, has the second pin 18 attached to the base end 17A side of the blade lifting cylinder 17 movably inserted therethrough. Like the second long slot 25 according to this embodiment, the second long slot 101 according to the comparative example has a protruding end 101A at its front end and a retracting end 101B at its rear end. However, the second long slot 101 has a horizontal groove 101C extending horizontally between the protruding end 101A and the retracting end 101B. Therefore, in the second long slot 101 of the comparative example, the distance C' from the pin connection 26 between the tip 17B of the blade lift cylinder 17 and the arm 13 to the second pin 18 does not increase continuously as it moves from the protruding end 101A to the retracting end 101B, but increases intermittently. In this respect, the second long slot 101 of the comparative example differs from the second long slot 25 of the present embodiment.

For this reason, in the comparative example, while the second pin 18 moves from the protruding end 101A of the second long slot 101 to the horizontal groove 101C, the distance C' from the pin connection 26 between the tip 17B of the blade lift cylinder 17 and the arm 13 to the second pin 18 is equal. Therefore, when the cylinder stopper 27 is removed from the cylinder support member 102 to move the base end 17A of the blade lift cylinder 17 to the retraction preparation position, the base end 17A of the blade lift cylinder 17 may suddenly fall from the protruding end 101A to the horizontal groove 101C due to its own weight.

In contrast, in this embodiment, the second long slot 25 of the cylinder support member 24 is formed as an arc-shaped long slot that extends obliquely downward from the protruding end 25A to the retracting end 25B. As a result, as described above, when the cylinder stopper 27 is removed from the cylinder support member 24 and the blade lift cylinder 17 is extended to move the base end 17A of the blade lift cylinder 17 from the protruding position (position in FIG. 5) to the retraction preparation position (position in FIG. 6), it is possible to prevent the base end 17A of the blade lift cylinder 17 from falling under its own weight, and the cylinder stopper 27 can be safely removed.

Thus, in the embodiment, the soil removal device 12 comprises an arm 13 having a left arm portion 13A whose base end side 13A1 is rotatably attached to the left blade support member 20 using a pin 14, and a right arm portion 13B whose base end side 13B1 is rotatably attached to the right blade support member 21 using a pin 14, a blade 16 attached to the tip 13E side of the arm 13, and a blade lifting cylinder 17 whose base end 17A side is rotatably attached to the cylinder support member 24 and whose tip 17B side is rotatably attached to the arm 13, and which raises and lowers the blade 16 relative to the left blade support member 20 and the right blade support member 21 in response to the extension and retraction operation. The pin holes of the left blade support member 20 and the right blade support member 21 through which the pin 14 is inserted are formed as long slots 22 into which the pin 14 engages so as to be movable in the fore-and-aft direction of the vehicle body, and the blade 16 is configured to be movable between a protruding position in which it protrudes away from the left blade support member 20 and the right blade support member 21, and a retracted position in which it is retracted toward the left blade support member 20 and the right blade support member 21, as the pin 14 moves along the long slots 22.

According to this configuration, the pins 14 connecting the base end side 13A1 of the left arm section 13A to the left blade support member 20 and the base end side 13B1 of the right arm section 13B to the right blade support member 21 can be moved along the long slots 22 formed in the left blade support member 20 and the right blade support member 21, thereby moving the blade 16 from the extended position to the retracted position. This reduces the length of protrusion of the blade 16 from the lower traveling body 2, preventing the blade 16 from interfering with surrounding obstacles when the hydraulic excavator 1 is rotating, ensuring good travelability.

In the embodiment, the left blade support member 20 is provided with a blade stopper 23 that fixes the pin 14 when the blade 16 moves to the extended or retracted position. With this configuration, the blade stopper 23 can be used to hold the blade 16 in the extended or retracted position.

In the embodiment, the base end 17A side of the blade lift cylinder 17 is rotatably attached to the cylinder support member 24 by using the second pin 18, and the pin hole of the cylinder support member 24 through which the second pin 18 is inserted is formed as a second long groove hole 25 into which the second pin 18 is engaged so as to be movable in the fore-aft direction of the vehicle body, and the base end 17A side of the blade lift cylinder 17 moves to a protruding position for putting the blade 16 in the protruding position and a retraction preparation position for moving the blade 16 from the protruding position to the retracted position by the second pin 18 moving in the fore-aft direction of the vehicle body along the second long groove hole 25. According to this configuration, for example, when moving the blade 16 from the protruding position to the retracted position, the base end 17A can be moved to the retraction preparation position by extending the blade lift cylinder 17. As a result, the stroke S when the blade lift cylinder 17 is contracted can be increased, and the blade 16 can be significantly retracted toward the left blade support member 20 and the right blade support member 21.

In the embodiment, the cylinder support member 24 is provided with a cylinder stopper 27 that fixes the second pin 18 when the base end 17A side of the blade lift cylinder 17 moves to the extended position or the retraction preparation position. With this configuration, the cylinder stopper 27 can be used to hold the base end 17A side of the blade lift cylinder 17 in the extended position or the retraction preparation position.

In the embodiment, the second long slot 25 formed in the cylinder support member 24 has a protruding end 25A with which the second pin 18 engages when the base end 17A side of the blade lift cylinder 17 is moved to the protruding position, and a retracting end 25B with which the second pin 18 engages when the base end 17A side of the blade lift cylinder 17 is moved to the retraction preparation position, and the distance C from the pin connection part 26 between the tip 17B of the blade lift cylinder 17 and the arm 13 to the second pin 18 increases continuously as the second pin 18 moves from the protruding end 25A to the retracting end 25B of the second long slot 25. With this configuration, the load on the base end 17A side of the blade lift cylinder 17 can be constantly received by the cylinder support member 24 while the blade lift cylinder 17 is extended, and the base end 17A of the blade lift cylinder 17 can be prevented from falling under its own weight.

In the embodiment, the pin holes of the left blade support member 20 and the right blade support member 21 are formed as long slots 22. However, the present invention is not limited to this, and may be configured as a modified example shown in FIG. 9. That is, the pin hole of the left arm portion 13A constituting the arm 13 may be formed as a long slot 22', and the pin 14 fixed to the left blade support member 20 may be inserted into this long slot 22', and the pin hole of the right arm portion 13B may be formed as a long slot (not shown), and the pin 14 fixed to the right blade support member 21 may be inserted into this long slot.

In the embodiment, the second long slot 25 formed in the cylinder support member 24 is illustrated as an arc-shaped long slot that extends continuously diagonally downward from the protruding end 25A to the retracting end 25B. However, the present invention is not limited to this, and the second long slot 25 may be formed as a straight line that extends diagonally downward at a constant inclination from the protruding end 25A to the retracting end 25B.

In addition, in the embodiment, an earth removal device 12 is illustrated in which an angle cylinder 19 is provided between the arm 13 and the blade 16. However, the present invention is not limited to this, and can also be applied to a hydraulic excavator equipped with an earth removal device that does not have an angle cylinder 19.

Furthermore, in the embodiment, the case where the invention is applied to a crawler-type hydraulic excavator 1 equipped with tracks 8 is illustrated. However, the invention is not limited to this, and can also be applied to, for example, a wheel-type hydraulic excavator.

2. Undercarriage (car body)
4. Upper rotating body (car body)
REFERENCE SIGNS LIST 12 Earth removal device 13 Arm 13A Left arm section 13B Right arm section 14 Pin 16 Blade 17 Blade lifting cylinder 18 Second pin 20 Left blade support member 21 Right blade support member 22, 22' Long slot 23 Blade stopper 24 Cylinder support member 25 Second long slot 26 Pin connection section 27 Cylinder stopper

Claims (5)

A self-propelled vehicle body and an earth removal device provided on the vehicle body,
The soil removal device is
an arm having a base end rotatably attached to a blade support member provided on the vehicle body by using a pin;
A blade attached to a tip side of the arm;
a blade lifting cylinder whose base end is rotatably attached to a cylinder support member provided on the vehicle body and whose tip end is rotatably attached to the arm, and which lifts and lowers the blade relative to the blade support member in response to an extension and retraction motion,
one of a pin hole provided in the blade support member through which the pin is inserted and a pin hole provided on a base end side of the arm is formed as a long slot into which the pin engages so as to be movable in the front-rear direction of the vehicle body;
a blade support member that supports the blade from the blade support member toward the blade support member; a retracted position in which the blade support member is retracted toward the blade support member; and a protruding position in which the blade support member is retracted toward the blade support member, by the pin moving in the fore-and-aft direction of the vehicle body along the long groove hole. The construction machine according to claim 1, characterized in that either the blade support member or the arm is provided with a blade stopper that fixes the pin when the blade moves to the extended position or the retracted position. a base end side of the blade lifting cylinder is rotatably attached to the cylinder support member by a second pin;
a pin hole of the cylinder support member through which the second pin is inserted is formed as a second long slot hole into which the second pin engages so as to be movable in the front-rear direction of the vehicle body;
2. The construction machine according to claim 1, characterized in that the base end side of the blade lifting cylinder can be moved between an extended position for placing the blade in the extended position and a retracted preparation position for moving the blade from the extended position to the retracted position by the second pin moving in the fore-and-aft direction of the vehicle body along the second long groove. The construction machine according to claim 3, characterized in that the cylinder support member is provided with a cylinder stopper that fixes the second pin when the base end side of the blade lifting cylinder moves to the extended position or the retraction preparation position. the second long slot formed in the cylinder support member has a protruding side end with which the second pin engages when the base end side of the blade lifting cylinder is moved to the protruding position, and a retracting side end with which the second pin engages when the base end side of the blade lifting cylinder is moved to the retraction preparation position,
4. The construction machine according to claim 3, wherein the distance from the pin connection between the tip of the blade lifting cylinder and the arm to the second pin continuously increases as the second pin moves from the protruding side end to the retracting side end of the second slot.

Images