JP7780370B2 - Work machinery - Google Patents

Description

The present invention relates to a work machine equipped with a hook and a quick hitch.

Patent Document 1 discloses a work machine that can perform lifting work by attaching a hook to the bucket link. This type of work machine can perform lifting work using the hook in addition to excavation work using the bucket.

Patent Document 2 also discloses a quick hitch that can be attached to the end of an arm to simplify the process of changing attachments depending on the work application. With such a work machine, attachments can be easily changed, making it possible to perform multiple types of work with a single machine.

Japanese Patent Application Laid-Open No. 2003-12267 Japanese Patent Application Laid-Open No. 2004-36635

Furthermore, by attaching the hook described in Patent Document 1 and the quick hitch described in Patent Document 2 to the end of the arm, the work machine can perform an even wider variety of tasks. However, when a quick hitch is attached to a work machine equipped with a hook, there is an issue in that the hook interferes with the quick hitch during lifting operations.

The present invention was made in consideration of the above-mentioned circumstances, and its purpose is to provide a work machine in which a hook and a quick hitch can be attached to the end of an arm without interfering with each other.

In order to achieve the above object, the present invention provides a work machine comprising a vehicle body, a boom connected to the vehicle body so as to be able to be raised and lowered, an arm rotatably connected to the tip of the boom, a quick hitch rotatably connected to the tip of the arm, an attachment detachably engaged with the quick hitch, a hook for suspending a load at the tip of the arm , and a pair of connecting links arranged opposite each other in the width direction of the vehicle body with the hook in between , wherein each of the pair of connecting links comprises a first connecting part rotatably connected to the tip of the arm, a second connecting part rotatably connected to the quick hitch, and a connecting part rotatably connected between the first connecting part and the second connecting part. and a third connecting part rotatably connected to the hook on the opposite side of the arm across the straight line connecting the connecting parts, the distance between the second connecting part and the third connecting part is longer than the overall length of the hook, each of the pair of connecting links comprises a first rod connecting the first connecting part and the second connecting part, a second rod connecting the second connecting part and the third connecting part, and a third rod connecting the first connecting part and the third connecting part, and a through hole penetrating each of the pair of connecting links in the thickness direction is formed in the area surrounded by the first rod, the second rod, and the third rod .

The present invention provides a work machine that allows a hook and a quick hitch to be attached to the end of an arm without interfering with each other. Issues, configurations, and advantages other than those described above will become clear from the description of the following embodiments.

1 is a side view of a work machine according to the present invention. FIG. 2 is an enlarged perspective view of the tip of the front working implement. FIG. 2 is an exploded perspective view of a hook and a triangular link. FIG. 10 is a side view showing the positional relationship between the quick hitch and the hook when the position of the arm is changed. FIG. 10 is a side view of a triangular link according to a modified example.

Embodiments of a work machine according to the present invention will be described with reference to the drawings. Figure 1 is a side view of a hydraulic excavator 1 according to the present invention. Note that, unless otherwise specified, the terms front, back, left, and right in this specification refer to the perspective of an operator who is riding on and operating the hydraulic excavator 1.

The hydraulic excavator 1 comprises a lower traveling body 2 and an upper rotating body 3 supported by the lower traveling body 2. The lower traveling body 2 and the upper rotating body 3 are an example of a vehicle body. The lower traveling body 2 comprises a pair of left and right crawlers. When the rotation of a traveling motor (not shown) is transmitted to rotate the pair of left and right crawlers, the hydraulic excavator 1 travels. However, the lower traveling body 2 may be wheeled instead of crawler-mounted.

The upper rotating body 3 is rotatably supported on the lower running body 2. The upper rotating body 3 mainly comprises a rotating frame 5 serving as a base, a cab (driver's seat) 7 located on the front left side of the rotating frame 5, a front work implement 10 attached to the center of the front end of the rotating frame 5 so that it can rotate up and down, and a counterweight 6 located at the rear of the rotating frame 5 to balance the weight of the front work implement 10.

The cab 7 has an interior space where the operator who operates the hydraulic excavator 1 sits. Inside the cab 7, there is a seat (not shown) where the operator sits, and operating devices (steering wheel, pedals, levers, switches, etc.) that the operator operates while seated in the seat. When the operator in the cab 7 operates the operating devices, the lower traveling body 2 travels, the upper rotating body 3 rotates, and the front working implement 10 operates.

The front work implement 10 is supported by the upper rotating body 3 and performs various tasks (e.g., excavation, demolition, and lifting). The front work implement 10 mainly comprises a boom 11, an arm 12, a quick hitch 13, a bucket 14 (attachment), a hook 15, a pair of triangular links 16 (connecting links), a straight link 17, a boom cylinder 18, an arm cylinder 19, and an attachment cylinder 20.

The boom 11 is connected to the upper rotating body 3 so that it can rotate (raise and lower) around a pin (not shown) that extends left and right (in the width direction of the upper rotating body 3). One end (cylinder tube side) of the boom cylinder 18 is rotatably supported by the upper rotating body 3, and the other end (cylinder rod side) is rotatably supported by the boom 11. The boom 11 is raised when the boom cylinder 18 extends, and lowered when the boom cylinder 18 retracts.

The arm 12 is connected to the tip of the boom 11 so as to be rotatable around a pin 21 extending in the left-right direction. One end (cylinder tube side) of the arm cylinder 19 is rotatably supported on the boom 11, and the other end (cylinder rod side) is rotatably supported on the arm 12. When the arm cylinder 19 extends, the tip of the arm 12 rotates in a direction away from the upper rotating body 3 (forward, upward), and when the arm cylinder 19 retracts, the tip rotates in a direction approaching the upper rotating body 3 (backward, downward).

The quick hitch 13 is rotatably connected to the tip of the arm 12 around a pin 22 extending in the left-right direction, and is rotatably connected to a pair of triangular links 16 around a pin 24 extending in the left-right direction. The quick hitch 13 also detachably engages the bucket 14. When the attachment cylinder 20 extends and retracts, the quick hitch 13 rotates integrally with the bucket 14 around the pin 22.

The bucket 14 is detachably supported by the quick hitch 13. Specific examples of the attachment are not limited to the bucket 14, but may include a grapple, cutter, breaker, etc. Here, "detachable" means that the bucket 14 can be easily attached and detached at the work site by extending and retracting the boom cylinder 18, arm cylinder 19, and attachment cylinder 20 in a predetermined order. More specifically, the quick hitch 13 has hooks that engage pins 14a and 14b that are attached to the bucket 14 and extend in the left-right direction. The structure for engaging the bucket 14 with the quick hitch 13 is already well known, so a detailed explanation will be omitted.

The hook 15 is connected to a pair of triangular links 16 so as to be rotatable around a pin 25 extending in the left-right direction. In other words, the hook 15 is rotatably supported at the tip of the arm 12 via the pair of triangular links 16. The hook 15 is configured so that it can hang cargo. The specific structure of the hook 15 is already well known, so a detailed description will be omitted.

A pair of triangular links 16 rotatably connect the arm 12, quick hitch 13, hook 15, linear link 17, and attachment cylinder 20. Furthermore, the pair of triangular links 16 support the hook 15 in a position that does not interfere with the quick hitch 13, regardless of the position of the boom 11, arm 12, and quick hitch 13.

Figure 2 is an enlarged perspective view of the tip of the front work implement 10. Figure 3 is an exploded perspective view of the hook 15 and triangular link 16. As shown in Figures 2 and 3, the hydraulic excavator 1 is equipped with a pair of left and right triangular links 16. More specifically, the pair of triangular links 16 are arranged opposite each other in the width direction of the upper rotating body 3, with the arm 12, quick hitch 13, and hook 15 between them. However, the left and right triangular links 16 have the same configuration. The same applies to the straight link 17.

When viewed from the left and right, the triangular link 16 has a generally triangular outer shape. The triangular link 16 is composed of a first connecting portion 31, a second connecting portion 32, a third connecting portion 33, a first rod 34, a second rod 35, and a third rod 36. The triangular link 16 may be integrally formed by casting, for example, or may be constructed by welding the components 31 to 36 together.

The first connecting portion 31, the second connecting portion 32, and the third connecting portion 33 are positioned at positions corresponding to the vertices of a triangle. Furthermore, the first connecting portion 31, the second connecting portion 32, and the third connecting portion 33 have an outer ring shape (cylindrical shape) into which the pins 23, 24, and 25 extending in the left-right direction are inserted. Specifically, the first connecting portion 31, the second connecting portion 32, and the third connecting portion 33 have through-holes 37 formed therethrough in the thickness direction (left-right direction).

As shown in FIG. 1, the first connecting portion 31 is rotatably connected to the linear link 17 and the attachment cylinder 20 via a pin 23. The second connecting portion 32 is rotatably connected to the quick hitch 13 via a pin 24. The third connecting portion 33 is rotatably connected to the hook 15 via a pin 25.

Here, the third connecting portion 33 is located on the opposite side of the arm 12, across the line connecting the first connecting portion 31 and the second connecting portion 32 (i.e., the first rod 34 described below). In other words, the third connecting portion 33 is located on the opposite side of the line connecting the first connecting portion 31 and the second connecting portion 32 from the pin 22 connecting the arm 12 and the quick hitch 13.

The attachment cylinder 20 has one end (cylinder tube side) rotatably supported by the arm 12, and the other end (cylinder rod side) rotatably connected to the first connecting part 31 around pin 23. Furthermore, the linear link 17 has one end rotatably connected to the first connecting part 31 around pin 23, and the other end supported by the arm 12 rotatably around pin 26.

In FIG. 1, when the attachment cylinder 20 is extended, the triangular link 16 and the linear link 17 rotate counterclockwise around the pin 26. As a result, the quick hitch 13 connected to the second connecting part 32 rotates counterclockwise around the pin 22 together with the bucket 14 (crowd). On the other hand, when the attachment cylinder 20 is retracted, the triangular link 16 and the linear link 17 rotate clockwise around the pin 26. As a result, the quick hitch 13 connected to the second connecting part 32 rotates clockwise around the pin 22 together with the bucket 14 (dump).

As shown in Figures 2 and 3, the first rod 34, second rod 35, and third rod 36 are arranged at positions corresponding to the sides of a triangle. More specifically, the first rod 34 connects the first connecting portion 31 and the second connecting portion 32. The second rod 35 connects the second connecting portion 32 and the third connecting portion 33. The third rod 36 connects the first connecting portion 31 and the third connecting portion 33.

The cross sections (cross sections perpendicular to the extension direction) of the first rod 34, second rod 35, and third rod 36 according to this embodiment are rectangular. However, the cross sections of the first rod 34, second rod 35, and third rod 36 may also be circular, elliptical, or other shapes. Furthermore, a through hole 37 that penetrates the triangular link 16 in the thickness direction (width direction of the upper rotating body 3) is formed in the area surrounded by the first rod 34, second rod 35, and third rod 36. When the triangular link 16 is viewed from the left and right, the shape of the through hole 37 according to this embodiment is triangular. However, the shape of the through hole 37 is not limited to the example described above.

In this embodiment, the relationship between the lengths of the first rod 34, second rod 35, and third rod 36 is as follows. Note that the length of the first rod 34 can be rephrased as the distance between the first connecting portion 31 and the second connecting portion 32, the length of the second rod 35 can be rephrased as the distance between the second connecting portion 32 and the third connecting portion 33, and the length of the third rod 36 can be rephrased as the distance between the first connecting portion 31 and the third connecting portion 33.

In this embodiment, the first rod 34 and the second rod 35 are the same length. Furthermore, the third rod 36 is shorter than the first rod 34 and the second rod 35. In other words, the triangular link 16 has the outer shape of a roughly isosceles triangle with the third rod 36 as its base. However, the relationship in length between the first rod 34, the second rod 35, and the third rod 36 is not limited to the example described above.

As another example, the second rod 35 and the third rod 36 may be the same length, and the first rod 34 may be shorter than the second rod 35 and the third rod 36, forming an isosceles triangle with the first rod 34 as the base. As yet another example, the second rod 35 may be longer than the first rod 34 and the third rod 36, forming a right triangle with the second rod 35 as the hypotenuse.

Furthermore, the second rod 35 (in other words, the distance between the first connecting portion 31 and the second connecting portion 32, or the distance between the pins 23 and 24) is longer than the overall length of the hook 15. This allows the hook 15 to rotate around the pin 25 between the working position and the storage position, which will be described later.

The working position is the position of the hook 15 with its tip on the opposite side of the second rod 35 (the straight line connecting the second connecting part 32 and the third connecting part 33) from the first connecting part 31. The working position is the position of the hook 15 when performing lifting work. On the other hand, the storage position is the position of the hook 15 along the second rod 35 with its tip facing the second connecting part 32. In other words, in the storage position, the hook 15 enters the inside of the pair of triangular links 16 so as to follow the second rod 35. The storage position is the position of the hook 15 when not performing lifting work (in other words, when performing work using an attachment).

Furthermore, as shown in FIG. 2, the pair of triangular links 16 are equipped with locking portions 38. The locking portions 38 lock the hooks 15 in the locked position. The locking portions 38 may be, for example, pins that engage the hooks 15, clips that clamp the hooks 15, or the like. The locking portions 38 are configured to be able to switch between locking and unlocking the hooks 15. The specific structure of the locking portions 38 is already well known, so a detailed description will be omitted.

Figure 4 is a side view showing the relative positions of the quick hitch 13 and hook 15 when the arm 12 is changed in position. As shown in Figure 4, lifting work using the hook 15 is performed with the bucket 14 in a crowding position (with the attachment cylinder 20 extended).

As shown in Figure 4(A), when the arm cylinder 19 is extended so that the tip of the arm 12 faces downward and forward, the distance between the quick hitch 13 and the hook 15 in the fore-and-aft direction increases. In other words, the angle that the second rod 35 makes with respect to the vertical direction increases. This prevents interference between the hook 15 and the load or wire suspended from the hook 15 during lifting operations. However, with the tip of the arm 12 facing downward and forward, the turning radius cannot be increased, and the lifting height of the load cannot be ensured.

To increase the turning radius and lifting height, the arm cylinder 19 is retracted so that the tip of the arm 12 faces forward. This narrows the distance between the quick hitch 13 and the hook 15 in the fore-and-aft direction, as shown in Figure 4(B). In other words, the angle that the second rod 35 makes with respect to the vertical direction becomes smaller.

However, in this embodiment, the triangular link 16 supports the hook 15 at the third connecting portion 33, which is on the opposite side of the line connecting the first connecting portion 31 and the second connecting portion 32 from the tip of the arm 12, thereby expanding the range of rotation of the arm 12 within which the hook 15 does not interfere with the quick hitch 13.

The above embodiment provides the following advantages, for example:

In the above embodiment, by attaching the hook 15 to the third connecting portion 33 of the pair of triangular links 16, it is possible to perform lifting operations while avoiding interference between the quick hitch 13 and the hook 15. In particular, the effect of avoiding interference between the quick hitch 13 and the hook 15 increases the longer the second rod 35, the longer the third rod 36, and the larger the angle between the first rod 34 and the second rod 35.

Furthermore, according to the above embodiment, by providing a through hole 37 in the center of each of the pair of triangular links 16, soil and sand that has entered between the pair of triangular links 16 during excavation work can be easily removed. As a result, it is possible to prevent soil and sand from getting stuck between the pair of triangular links 16, preventing the hook 15 from being able to rotate from the storage position to the working position. Furthermore, by providing the through hole 37, the weight of the pair of triangular links 16 can be reduced.

Furthermore, according to the above embodiment, by making the second rod 35 longer than the overall length of the hook 15, the hook 15 can be stored along the second rod 35. Furthermore, by pointing the tip of the hook 15 in the storage position toward the second connecting portion 32, the rotation angle of the hook 15 between the working position and the storage position is reduced, so even if the hook 15 unintentionally rotates from the storage position to the working position during excavation work, for example, the load on the components can be reduced.

Note that while lengthening the third rod 36 increases the interference avoidance effect, it may also reduce the lifting load due to a decrease in the rigidity of the pair of triangular links 16. Therefore, the thickness (cross-sectional area of the transverse cross section) of the third rod 36 may be made thicker than those of the first rod 34 and the second rod 35. This increases both the interference avoidance effect and the lifting load.

Furthermore, as shown in FIG. 1, when the hydraulic excavator 1 is in the transport posture (a posture in which the boom cylinder 18, arm cylinder 19, and attachment cylinder 20 are fully retracted), the third connecting portion 33 comes into contact with the ground. This becomes more pronounced as the third rod 36 is longer. Therefore, as shown in FIG. 5, the angle formed by the first rods 34A, 34B and the second rods 35A, 35B (in other words, the length of the third rods 36A, 36B) may be made variable. FIG. 5 is a side view of triangular links 16A, 16B according to a modified example.

As shown in Figure 5, the triangular links 16A and 16B according to the modified example are similar to the triangular link 16 according to the above embodiment in that they are composed of first connecting portions 31A and 31B, second connecting portions 32A and 32B, third connecting portions 33A and 33B, first rods 34A and 34B, second rods 35A and 35B, and third rods 36A and 36B.

On the other hand, the triangular links 16A, 16B according to the modified example differ from the triangular link 16 according to the above embodiment in that the angle between the first rods 34A, 34B and the second rods 35A, 35B is variable. The following methods, for example, can be considered to make the angle between the first rods 34A, 34B and the second rods 35A, 35B variable.

As one example, the triangular link 16A shown in Figure 5(A) includes an extendable third rod 36A. A specific example of the third rod 36A is a multi-stage cylinder that extends and retracts cylinders of different diameters. As another example, the triangular link 16B shown in Figure 5(B) includes a bendable third rod 36B. Although not shown, as another example, the triangular link may include a third rod made of a belt sling.

In the above modified example, the angle between the first rods 34A, 34B and the second rods 35A, 35B is increased when performing lifting operations, and the angle between the first rods 34A, 34B and the second rods 35A, 35B is decreased when transporting the hydraulic excavator 1. This avoids interference between the quick hitch 13 and the hook 15 during lifting operations and prevents the triangular links 16A, 16B from contacting the ground during transport.

The above-described embodiments are illustrative examples of the present invention and are not intended to limit the scope of the present invention to these embodiments. Those skilled in the art may implement the present invention in various other forms without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Hydraulic excavator 2 Undercarriage 3 Upper rotating body 5 Swing frame 6 Counterweight 7 Cab 10 Front work implement 11 Boom 12 Arm 13 Quick hitch 14 Bucket 15 Hook 16, 16A, 16B Triangular link 17 Straight link 18 Boom cylinder 19 Arm cylinder 20 Attachment cylinder 14a, 14b, 21, 22, 23, 24, 25, 26 Pin 31, 31A, 31B First connecting portion 32, 32A, 32B Second connecting portion 33, 33A, 33B Third connecting portion 34, 34A, 34B First rod 35, 35A, 35B Second rod 36, 36A, 36B Third rod 37 Through hole 38 Locking portion

Claims (4)

The car body and
a boom connected to the vehicle body so as to be able to be raised and lowered;
an arm rotatably connected to the tip of the boom;
a quick hitch rotatably connected to the tip of the arm;
an attachment detachably engaged with the quick hitch;
a hook for suspending a load at the tip of the arm ;
a pair of connecting links disposed opposite each other in a width direction of the vehicle body with the hook in between ,
Each of the pair of connecting links is
a first connecting portion rotatably connected to a tip end of the arm;
a second connecting portion rotatably connected to the quick hitch;
a third connecting portion rotatably connected to the hook on the opposite side of the arm across a straight line connecting the first connecting portion and the second connecting portion,
The distance between the second connecting portion and the third connecting portion is longer than the entire length of the hook,
Each of the pair of connecting links is
a first rod connecting the first connecting portion and the second connecting portion;
a second rod connecting the second connecting portion and the third connecting portion;
a third rod connecting the first connecting portion and the third connecting portion,
A work machine characterized in that a through hole penetrating each of the pair of connecting links in a thickness direction is formed in the area surrounded by the first rod, the second rod, and the third rod . 2. The work machine according to claim 1 ,
the second rod is longer than the entire length of the hook;
The hook is
a working position where a tip end of the second rod is located on the opposite side of the first connecting portion across the second rod;
a storage position along the second rod with a tip end facing the second connecting portion, and a third connecting portion rotatably connected to the third connecting portion;
A work machine characterized in that the pair of connecting links are provided with locking portions that lock the hooks in the stored position. 2. The work machine according to claim 1 ,
A work machine, wherein the third rod is thicker than the first rod and the second rod. 2. The work machine according to claim 1 ,
A work machine, characterized in that in each of the pair of connecting links, the angle formed by the first rod and the second rod is variable.