JPH0912278A - Counter weight attaching and detaching device - Google Patents

Abstract

PURPOSE: To provide a counter weight attaching and detaching device, by which a counter weight having the weight and the shape suitable for crane performance can be easily and safely attached and detached. CONSTITUTION: When a rod 20a is extended, an upper arm 12 is turned upward centered on a pin 13, and a cutout part 12a is engaged with a pin 32. Moreover, a lower arm 14 is turned downward centered on a pin 15, and a cutout part 14a is engaged with a pin 33. Since the length of an arm of moment for turning the upper arm 12 upward is long, the moment is larger than that for turning the lower arm downward, and counter weights 31a to 31d are lifted when the rod 20a is further extended. When the rod 20a is further extended, respective links 16, 18 are linearly connected to each other, turned beyond the linear state, bent in the opposite direction to the state, and the connecting part is brought in contact with a stopper 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a counterweight attaching / detaching apparatus for attaching / detaching a counterweight mounted on a construction machine such as a crane or a hydraulic shovel by itself.

[0002]

2. Description of the Related Art In self-propelled cranes, a counterweight is attached to the rear end of an upper revolving structure in order to improve the stability of the body and increase the lifting capacity. The counterweight needs to be detached when the lifting capacity is adjusted according to the work or when the body is disassembled and transported. Attachment / removal of the counterweight was initially inconvenient because it was performed with the help of another auxiliary crane. For this reason, the counterweight has conventionally been detached and attached only by the crane to be detached and attached as follows.

First, in the first prior art, one end of a wire rope is connected to the tip of a basic boom, and this wire rope is wrapped around a sheave provided on an A-frame at the rear of the fuselage. The other end is connected to the counterweight. The attachment and detachment of the counterweight is performed by itself by raising and lowering the basic boom and pulling the wire rope.

In the second prior art, a cylinder is provided as a detachable device above the rear part of the fuselage, and a rod end of the cylinder is connected to a counterweight. The attachment and detachment of the counterweight is performed by itself by expanding and contracting the rod of the cylinder.

The third prior art is disclosed in Japanese Patent Publication No. 3-754.
In the attaching and detaching device disclosed in Japanese Patent Publication No. 78 and 78, an arm is attached to the rear portion of the swivel base vertically separated from each other, and a hydraulic cylinder is stretched between the arms. The counterweight is detached and attached by itself by the expansion and contraction of the hydraulic cylinder. That is, the arms connected to the cylinder are rotated by the extension of the cylinder, and the receiving portions of the arms are engaged with the engaging portions provided on the counterweight. The moment force from the cylinder is transmitted to the counterweight via this arm, and the counterweight is lifted.

[0006]

However, each of the conventional counterweight attaching / detaching structures described above has the following problems.

That is, in the first and second conventional structures, it is necessary to suspend the center of gravity of the counterweight by a wire rope or a cylinder in order to raise and lower the counterweight in a well-balanced manner.
For this reason, in the above-mentioned conventional attachment / detachment structure, the counterweight must be manufactured so that the center of gravity of the counterweight is directly below the lifting point by the wire rope or the cylinder. Therefore, it is necessary to consider the position of the center of gravity when manufacturing the counterweight, and the counterweight cannot be easily manufactured. In addition, since the position of the center of gravity is determined in advance, the shape of the counterweight itself is restricted, and the counterweight cannot be manufactured in a desired shape.

When the counterweight is made heavy, it is necessary to stack the counterweight before mounting the counterweight on the body. In such a case,
In the above-described conventional counterweight detachable structure for lifting the center of gravity, even if the stacking position of the counterweights is slightly displaced, the lifting balance is greatly disturbed when the counterweights are detached and attached, resulting in instability. For this reason, the work of stacking the counterweights requires caution, and the workability is poor and dangerous.

In the third conventional detachable structure, the load of the counterweight is directly applied to the hydraulic cylinder via the arm. For this reason, as described in the publication, in order to prevent the hydraulic cylinder from inadvertently sagging due to oil leakage of the hydraulic cylinder, the arm is moved to the swivel with a pin or the like while the counterweight is raised. Need to be fixed. Therefore, in the third conventional structure, it is necessary to hit a fixing pin after mounting the counterweight.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and has a base end pivotally supported at an upper portion of a rear end of a revolving frame and an upper engagement portion provided at a tip end. Upper arm, a lower end having a base end pivotally supported by a lower rear end of the turning frame and a lower engagement portion provided at a distal end, and one end pivotally supported by the upper arm and the lower arm, respectively. A first link and a second link, the other ends of which are connected to each other.
And a cylinder pivotally supported by the revolving frame for pushing and pulling the connecting portion of the first link and the second link, and an upper side provided on a counterweight portion facing the rear end of the revolving frame. The upper engaging portion engaged by the engaging portion and the lower engaging portion provided on the counterweight portion below the upper engaging portion and engaged by the lower engaging portion are linearly connected. On the opposite side of the cylinder with the first link and the second link interposed therebetween, there is provided a stopper provided at a counterweight portion where the connecting portion of each link abuts. The distance from the pivot between the first link to the pivot between the lower arm and the pivot frame is set longer than the distance from the pivot between the lower arm and the pivot between the lower arm and the second link. You configure the device.

[0011]

When the cylinder extends, the lower arm pivots downward about the pivot between the pivot frame and the lower arm by the pressing force from the cylinder via the second link, and the lower arm provided on the counterweight is rotated. Engage with the locking part. The upper arm pivots upward about a pivot axis between the upper frame and the turning frame by a pressing force from the cylinder via the first link,
Engage with the upper locking portion provided on the counterweight.

The distance between the pivot between the upper arm pivot frame and the first link and the pivot between the lower arm pivot frame and the second link are different from each other. It is set longer than the distance to the Axis. For this reason, the moment for rotating the upper arm upward is greater than the moment for rotating the lower arm downward, and when the cylinder is further extended, the counterweight is lifted by this difference in moment. At this time, since the lower arm is engaged with the lower locking portion of the counterweight, even if the center of gravity of the counterweight is located behind the upper arm, the counterweight is centered on the upper arm. It does not rock.

Further, when the cylinder is extended, the first link and the second link are connected linearly. When the cylinder further extends, each link rotates beyond this linear state and bends in the direction opposite to the previous state, and the connecting portion of each link comes into contact with the stopper provided on the counterweight, and The rotation stops. Since this stopper is provided on the opposite side of the cylinder across the links connected linearly, in this state, the load of the counterweight is applied to each link and does not apply to the cylinder.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a description will be given of a case where the counterweight detaching device according to one embodiment of the present invention is applied to an all terrain crane.

FIG. 4 shows a side view of the all terrain crane, in which an upper revolving unit 2 is mounted on a truck type traveling unit 1. The main boom 3 is raised and lowered by a raising and lowering cylinder 4, and a main hook 5 is suspended from a tip of the main boom 3. The counterweight attaching / detaching device 6 according to the present embodiment is configured at the rear end of such an upper swing body 2.

FIG. 1 is an enlarged cross-sectional view of the counterweight attaching / detaching device 6, showing a state before the counterweight is attached.

All the mechanisms of the upper revolving unit 2 are mounted on the revolving frame 11, and an upper arm 12 is pivotally supported on the upper rear end of the revolving frame 11. That is, the base end of the upper arm 12 is rotatably supported by the pin 13 above the rear end of the turning frame 11. A semicircular notch 12a opening upward is formed at the tip of the upper arm 12, and constitutes an upper engaging portion. A base end of a lower arm 14 is pivotally supported by a pin 15 at a lower rear end of the turning frame 11. The lower arm 14 rotates about the pin 15 as a pivot. At the tip of the lower arm 14, a notch 14a in the form of a semicircular arc that opens downward is formed to form a lower engaging portion.

The upper arm 12 has one end of a first link 16 pivotally supported by a pin 17, and the lower arm 14 has one end of a second link 18 pivotally supported by a pin 19. The other end of each of the first link 16 and the second link 18 is connected to a rod 20 of the hydraulic cylinder 20.
The pin is connected to the end of “a” by a pin 21. Each link 16,
Reference numeral 18 rotates around the pin 21 as a pivot. The base end of the tube 20b of the hydraulic cylinder 20 is pivotally supported by a bracket 11a provided in front of the turning frame 11 from the rear end, and the hydraulic cylinder 20 rotates about the pin 22 as a pivot.

The counterweights 31a to 31d are stacked on the truck chassis 1a of the truck-type traveling body 1 behind the traveling cab. A groove is formed in the lowermost counterweight 31a in a portion facing the rear end of the revolving frame 11. Revolving frame 1 in this groove
A pin 32 is provided at a portion facing the rear end of 1.
The notch 12a of the upper arm 12 is engaged with the pin 32 from below, and the pin 32 forms an upper locking portion.
Further, a pin 33 is provided in a counterweight portion below the pin 32. The pin 33 constitutes a lower locking portion, and the notch 14a of the lower arm 14 is engaged from above. In the above-mentioned groove of the counterweight 31a,
A stopper 34 is provided on the surface facing the rear end of the revolving frame 11.
Are formed. When the first link 16 and the second link 18 are connected linearly, the stopper 34
On the opposite side of the cylinder 20 with these links 16 and 18 connected linearly interposed therebetween, the link 20 is provided at a position where the connecting portions of the links 16 and 18 abut.

A distance A from a pin 13 which is a pivot between the upper arm 12 and the revolving frame 11 to a pin 17 which is a pivot between the upper arm 12 and the first link 16.
From the pin 15 which is the pivot between the lower arm 14 and the pivot frame 11 to the lower arm 14 and the second link 1
It is set longer than the distance B to the pin 19 which is the pivot between the eight.

The width of the counterweights 31a to 31d is substantially equal to the width of the truck chassis 1a.
The above-described counterweight attaching / detaching mechanism including the components 2 and 14, the links 16 and 18, the hydraulic cylinder 20, the stopper 34, and the like is configured as a pair on the right and left rear ends of the turning frame 11.

In such a structure, the mounting of the counterweights 31a to 31d is performed as follows.

First, the upper swing body 2 swings, and the rear end of the upper swing frame 11 is opposed to the counterweight 31a. Next, pressure oil is supplied to the hydraulic cylinder 20,
The rod 20a is extended. When the rod 20a extends,
The connecting portion between the first link 16 and the second link 18 is pressed, and the connecting state of each link 16, 18 tends to approach the linear state from the bent state. Therefore, the lower arm 14
The pin 1 which is a pivot between the turning frame 11 and the pin 1 is pressed by the pressing force from the rod 20a through the second link 18.
5 is pivoted downward. Therefore, the notch 14a of the lower arm 14 is engaged with a pin 33 provided on the counterweight 31a, as shown in FIG. In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. Also, the upper arm 12 has a first
With the pressing force from the rod 20a via the link 16 of the above, the pin 20 is pivoted upward about the pin 13 which is a pivot between the pivot frame 11 and the pivot frame 11. Therefore, the notch 12a of the upper arm 12 engages with the pin 32 provided on the counterweight 31a.

The distance A corresponding to the arm length of the moment for driving the upper arm 12 upward is, as described above, the distance B corresponding to the arm length for the moment for driving the lower arm 14 downward. Is also set long. For this reason,
The moment for rotating the upper arm 12 upward is larger than the moment for rotating the lower arm downward, and when the rod 20a is further extended, the counterweights 31a to 31d are lifted by this difference in moment. At this time, the lower arm 14 is in a state of being engaged with the pin 33 of the counterweight 31a, and this lower arm 14 It has the function of stopping the rotation of ~ d. Therefore, the counter weight 31
Even if the center of gravity of a to d is located behind the lifting portion of the upper arm 12, the counterweights 31a to 31d do not swing around the upper arm 12.

When the rod 20a further extends, the first link 16 and the second link 18 are connected linearly. When the rod 20a further extends, each link 16, 1
8 rotates beyond this linear state and bends in the opposite direction to the previous state. The connecting portions of the links 16 and 18 abut against the stopper 34 as shown in FIG. In this figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted. As a result, the rotation of each of the links 16 and 18 is stopped, and the counterweights 31a to 31d are held at that position. Since the stopper 34 is provided on the opposite side of the hydraulic cylinder 20 across the links 16 and 18 connected linearly, in this holding state, the load of the counterweights 31a to 31d is reduced. And does not start on the hydraulic cylinder 20.

On the other hand, when removing the counterweights 31a to 31d, the hydraulic cylinder 20 in the extended state is contracted. When the rod 20a is contracted, each link 1
6 and 18 operate in the reverse of the above-described manner, and the counterweights 31a to 31d are mounted on the truck chassis 1a.

According to the counterweight attaching / detaching apparatus according to the present embodiment, as described above, regardless of the center of gravity of the counterweights 31a to 31d, the counterweight 31a can be used.
~ D can be desorbed. Therefore, it is not necessary to suspend and lower the center of gravity of the counterweights 31a to 31d when detaching and attaching the counterweights. Therefore, it is not necessary to consider the position of the center of gravity when manufacturing the counterweight, and the counterweight can be easily manufactured. In addition, there is no restriction on the shape of the counterweight, and the counterweight can be manufactured in a desired shape. Further, even when the stacking position is slightly shifted during the stacking of the counterweights and the center of gravity position changes, the counterweights 31a to 31d can be detached without breaking the lifting balance. For this reason, the work of stacking the counterweights, which has conventionally required carefulness, can be easily performed, and the workability is improved. Moreover, the work can be performed safely.

Further, according to the counterweight attaching / detaching apparatus according to the present embodiment, the counterweight 31
The loads a to d are not applied to the hydraulic cylinder 20 at the time of mounting. For this reason, even if a hydraulic pressure leak occurs in the hydraulic cylinder 20, the load of the counterweights 31a to 31d is supported by the above-described link mechanism (toggle mechanism). That is, when the hydraulic pressure leaks, the links 16 and 18 try to rotate in the opposite direction to the direction at the time of mounting, but cannot rotate by the stopper 34, so that the counterweights 31a to 31d are held at that position. Accordingly, in order to prevent the hydraulic cylinder from inadvertently sagging due to a hydraulic leak as in the related art, there is no need to perform an operation of hitting a fixing pin to the arm after the counterweight is mounted. Therefore, according to the present embodiment, labor for attaching and detaching the counterweight can be omitted, and labor can be saved.

In the above embodiment, the case where the present invention is applied to an all terrain crane has been described. However, the present invention may be applied to other construction machines, and the same effects as in the above embodiment can be obtained.

[0030]

As described above, according to the present invention, it is not necessary to suspend the center of gravity of the weight when attaching and detaching the counterweight, so that the counterweight having the optimum weight and shape for crane performance can be easily and safely attached and detached. It becomes possible. Further, after the counterweight is attached, the work of hitting the fixing pin, which has been conventionally required, becomes unnecessary, and the labor of the attaching and detaching work can be saved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state before a counterweight is mounted by a counterweight attaching / detaching device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state where the counterweight is being mounted by the counterweight attaching / detaching device according to the present embodiment.

FIG. 3 is a cross-sectional view showing a state in which the counterweight is attached by the counterweight attaching / detaching device according to the present embodiment.

FIG. 4 is a side view of an all terrain crane provided with a counterweight attaching / detaching device according to the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Upper turning frame 11a ... Bracket 12 ... Upper arm 12a ... Notch (upper engagement part) 13, 15, 17, 19, 21, 22 ... Pin 14 ... Lower arm 14a ... Notch (lower engagement) 16) First link 18 ... Second link 20 ... Hydraulic cylinder 20a ... Rod 20b ... Tube 31a-d ... Counterweight 32 ... Pin (upper locking part) 33 ... Pin (lower locking part) 34 ... Stopper

Claims (1)

[Claims] 1. An upper arm having a base end pivotally supported at an upper rear end of a revolving frame and an upper engaging portion provided at a distal end, and an upper arm having a base end pivotally supported at a lower rear end of the revolving frame. A lower arm provided with a lower engaging portion, a first link having one end pivotally supported by the upper arm, and a first link having one end pivotally supported by the lower arm and the other end being the first link. A second link connected to the other end of the first link, a cylinder pivotally supported by the revolving frame for pushing and pulling a connecting portion between the first link and the second link, and a rear end of the revolving frame An upper engaging portion provided with the upper engaging portion provided on the counter weight portion to be engaged, and a lower engaging portion provided with the lower engaging portion provided on the counter weight portion below the upper engaging portion. The first link and the second link linearly connected to a side locking portion And a stopper provided on a counterweight portion where a connecting portion of the first link and the second link abuts on the opposite side of the cylinder with respect to the upper arm and a pivot provided between the upper arm and the turning frame. The distance from the pivot between the arm and the first link is set longer than the distance from the pivot between the lower arm and the pivot frame to the pivot between the lower arm and the second link. A counterweight removal / attachment device.