JPH0752185Y2 - Suspending structure for hooks of earthworking machines - Google Patents

Description

[Detailed Description of the Invention] << Industrial Application Field >> This invention is applied to an earthmoving machine such as a power shovel with a crane in which a bucket for earthwork and a detachable hook for lifting work are provided at the tip of a boom. The present invention relates to a suspension structure for the hook.

<< Prior Art >> An earthworking machine is known in which a hook is attached to the tip end of a boom such as a power shovel that can be raised and lowered so that a simple lifting operation can be performed. In the lifting work by this type of earthworking machine, the lifting load is limited to a low value from the viewpoint of safety. But generally, earthmoving machines
Booms can usually be driven with a force far greater than this limited load, and even when the same load is lifted, the force that acts on the boom changes depending on the boom angle, so lifting work that exceeds the allowable load can be performed. It is often dangerous to be broken. Therefore, in order to avoid such a danger, a device for detecting the lifting load by detecting the hydraulic pressure of the boom lifting cylinder and a device for detecting the load with the load detector installed on the hook suspension line are provided. Excavators with cranes are provided.

<Problems to be solved by the invention> In the case where the lifting load is detected by the hydraulic pressure of the boom lifting cylinder, it is necessary to lift the suspended object with the boom at a predetermined constant angle to detect the hydraulic pressure. Yes, the load detection operation is troublesome and the error is large. On the other hand, the one equipped with a load detector can detect the lifting load accurately, but for that purpose, the suspension line of the hook must be vertical at all times, which improves operability and work safety. Also from above, it is necessary that the suspension line of the hook and the bucket do not interfere with each other during the slinging work. Therefore, the conventional structure has a drawback that the structure of the suspension and the load detector is complicated and the device is expensive.

Therefore, an object of the present invention is to provide a hook suspension structure that can provide the device at a lower cost, can detect the load by a simple operation, and can safely perform the lifting operation itself.

<< Means for Solving the Problems >> In the present invention, the bucket 4 is swingably provided at the tip of the boom 3, and the bucket 4 is swung through the connecting ring 7 by the bucket cylinder 15 provided substantially parallel to the boom 3. In the earthmoving machine 1 being driven, a hook 13 is suspended on the back side of the bucket 4 via an extension tool 9 and a load detector 11. The suspension 9 includes a first bracket 9a and a second bracket 9b,
The base end of the first bracket 9a is pivotally attached to the connecting link 6 at a position opposite to the bucket side from the pivot position of the second bracket 9b, and the base end of the second bracket 9b is closer to the bucket side than the pivot position of the first bracket 9a. Is pivotally attached to the connecting link 6 at the position.
The tip of the second bracket 9b is pivotally attached to an intermediate position of the first bracket 9a, and the hook 13 is attached to the tip of the first bracket 9a extending further from the pivotal attachment position of the second bracket 9b to the back side of the bucket 4. It is suspended. The load detector 11 is
A main body and a pressure sensor 34 are provided, and the main body includes an upper member 25 and a lower member.
It is divided into 17 and. The upper member 25 and the lower member 17 are relatively movable in the suspension direction of the hook, and a sealed area 29 in which a fluid is enclosed is formed between the two members 25 and 17, and the pressure sensor
34 detects the pressure of the fluid enclosed in the closed area 29.

<< Operation >> The lifting operation is performed in a state where the bucket 4 is swung to the boom 3 side. In this state, since the claws of the bucket 4 are not suitable for the slinging operator, there is less risk of injury to the worker due to contact with the bucket 4, and work safety is high. When the suspended object is hung on the hook 13 and lifted, the load acts on the fluid in the sealed region 29 to increase the pressure, which is detected by the pressure sensor 34. Since the fluid pressure in the closed region 29 is proportional to the load, the lifting load applied to the hook 13 can be immediately known from the detected value, and this can be digitally displayed on the panel 37 of the operator's cab 36.

Since the hook 13 is suspended at the tip of the suspending tool 9 that projects to the rear side of the bucket 4, it is possible to prevent the suspension line of the hook 13 and the bucket 4 from interfering with each other even when the boom 3 stands up. Moreover, the suspension 9 has a simple structure and is strong,
It can be easily attached to and detached from the boom 3. Further, since the hook 13 is suspended from the tip of the first bracket 9a extending obliquely from the side opposite to the bucket of the connecting link 6 to the side of the bucket, even when the boom 3 is erected, the load in the rod retracting direction is applied to the bucket cylinder 15 in the rod retracting direction. Does not hang. When a force in the rod retracting direction acts on the bucket cylinder 15 due to the load suspended on the hook 13, the bucket 4 swings and interferes with the suspension line of the hook 13, so that the load cannot be accurately detected, so that it is difficult to detect the load during slinging work. Operability and work safety are impaired.

<< Embodiment >> FIG. 3 is a side view of a power shovel having a hook suspension structure of the present invention, and FIG. 1 is an enlarged view of a main part of FIG. In the figure, 1 is a power shovel, 2 and 3 are booms, 4 is a bucket that is swingably attached to the tip of the boom 3, 6 is a connecting link pivotally attached to the bucket 4 by a pin 5, and 7 is a boom 3. A swing link pivotally attached, 8 is a pin connecting the links 6, 7. Reference numeral 9 denotes a suspending tool, which includes a first bracket 9a having a base end pivotally attached to an intermediate position of the connecting link 6 and a second bracket 9b having a base end pivotally attached to the bucket-side pin 5 of the connecting link 6, The tip of the two brackets 9b is connected to the tip of the intermediate portion of the first bracket 9a with a pin 9c to form a triangular shape.
The tip of the first bracket 9a extends to the back side of the bucket 4 beyond the pivot position of the second bracket 9b. 10 is a U-shaped hanging metal fitting which is detachably pivoted to the tip of the suspension 9 by a connecting pin 40, 41 is a joint, 11 is a load detector connected to the joint 41, and 12 is a load detector 11. The chain 13 is a hook attached to the tip of the chain 12. The boom 3 is swung by a hydraulic cylinder 14 provided on the boom 2, and the bucket 4 is swung by a hydraulic cylinder 15 provided on the boom 3 via a link 6.

FIG. 2 is a sectional view of the load detector. The main body of the load detector is formed by a bottomed cylindrical lower member 17 and a rectangular columnar upper member 25.The lower member 17 is formed by fastening a cylindrical member 17a and a cup-shaped member 17b with a screw ring 18. It is an integrated structure. Reference numeral 19 is a through hole formed in the bottom plate 20 of the lower member 17, 21 is a connecting tool fitted in the through hole 19, 22 is a bearing that supports the connecting tool 21 in a rotatable manner, and 23 is a connecting tool 21. A chain 12 is connected to the through hole formed at the tip. 24 is the lower member
An upper member 25 is a small-diameter portion projectingly provided on the upper inner peripheral surface of the upper member 17, and is fitted in the small-diameter portion 24 in an airtight and slidable manner. Reference numeral 26 is a through hole formed in the upper portion of the upper member 25, and the joint 41 is connected to this through hole. 27 is a large diameter part formed below the upper member 25,
This large-diameter portion 27 is a piston that is fitted in an inner diameter surface of the lower member 17 in an airtight and slidable manner. 28 is a stopper that regulates the movement stroke of the large diameter portion 27, 29 is a ring-shaped pressure oil chamber formed between the small diameter portion 24 and the large diameter portion 27, 30 and 31 are seal rings, and 32 is an upper portion. Vertical hole opened on the bottom surface of the member 25,
33 is a horizontal hole communicating the vertical hole 32 and the pressure oil chamber 29, 34 is a vertical hole
An electric pressure sensor mounted at the open end of 32, 35 is a cable of the pressure sensor 34, and 38 is a blind plug that closes the oil filling opening in the pressure oil chamber 29. The cable 35 is guided to the operator's cab 36 of the power shovel 1 along the suspension device 9 and the booms 2 and 3, and is connected to the digital display panel 37 of the operator's cab.

To lift the suspended object with the power shovel 1, swing the bucket 4 to the boom 3 side with the hydraulic cylinder 15 and connect the suspension metal fitting 10 with the connecting pin 40 to the suspending tool 9 on the back side of the bucket 4. Attach the hook 13. And hook 13
Hang a suspended object on the floor and raise the booms 2 and 3 to lift the suspended object. The moment the product is lifted, the weight of the suspended object is the load detector.
Since it is detected in 11 and displayed on the panel 37 of the cab 36,
If the displayed value is within the allowable load, continue the lifting work,
If the displayed value exceeds the allowable load, the lifting work should be stopped.

<Effect of device> As described above, the structure for suspending the hook of the present invention is one in which the hook is suspended through the load detector to the suspending tool extending to the back side of the bucket. The suspension line and the bucket do not interfere with each other, and when the boom is erected, the bucket cylinder is not subjected to a suspended load in the rod retraction direction and the bucket is not swung, so work can be performed smoothly and safely. it can. In addition, the load detector
Since the structure is such that the pressure change of the fluid enclosed in the sealed area formed inside is detected by the pressure sensor, the lifting load can be accurately detected and the device can be provided at a low cost, and the dangerous load exceeding the allowable load can be detected. Lifting work can be avoided.

[Brief description of drawings]

FIG. 1 is an enlarged side view of the hook suspension structure of the present invention, and FIG.
FIG. 3 is a sectional view of a load detector, and FIG. 3 is a side view of a power shovel having a suspension structure according to the present invention. In the figure, 1: Power shovel, 3: Boom 4: Bucket, 6: Connection link 9: Suspension tool, 9a: First bracket 9b: Second bracket, 11: Load detector 12: Chain, 13: Hook 15: Bucket cylinder, 17: Lower member 25: Upper member, 29: Pressure oil chamber 34: Pressure sensor

Claims (1)

[Scope of utility model registration request] 1. A boom (3) is provided with a swingable bucket (4), and the bucket is swingable through a connecting ring (6) in a bucket cylinder (15) provided substantially parallel to the boom. In the structure of the earthmoving machine (1) that is driven and has a hoisting hook (13) suspended at the end of the boom, the hoisting tool (9) that suspends the hook (13) is , A first bracket (9a) whose base end is pivotally attached to the side opposite to the bucket side of the second bracket (9b) of the connection link (6) below, and the first end of the connection link (6) above
A second bracket (9b) pivotally attached to the bucket side from the pivotal attachment position of the bracket (9a) and having its tip pivotally attached to an intermediate position of the first bracket (9a), and the hook (13) includes the second bracket ( The load detector (11) is suspended by a load detector (11) at the tip of a first bracket (9a) extending to the back side of the bucket (4) beyond the pivot position of the load detector (11).
Is an upper member (2 that can move relative to the suspension direction of the hook (13).
Sealed area (29) formed between 5) and the lower member (17)
And a hook suspension structure for an earthworking machine, comprising a pressure sensor (34) for detecting the pressure in the closed region.