JPH07268908A - Counter weight mounting-demounting device for work machine - Google Patents

Abstract

PURPOSE:To simplify loading-unloading work of a counter weight, and eliminate nonconformity such as rotary arms interfere with an engine cover or the other obstacle by enlarging a hanging-up height when the counter weight is raised and lowered. CONSTITUTION:A raising lowering mechanism 23 to raise and lower a counter weight 22 to the rear end side of a turning frame 3 is composed of rotary arms 26 whose base end sides are joined to respective brackets 25 by pins through a connecting pin 27 and tip sides are connected to the counter weight 22 through a connecting pin 28 and respective connecting tools 29 or the like and raising-lowering cylinders 31 whose base end sides are joined to the respective brackets 25 by pins through a connecting pin 35 and tip sides are joined to the tip sides of the respective rotary arms 26 by pins through a connecting pin 33. Rods 31B of the raising-lowering cylinders 31 are extended and contracted from tubes 31A, and the counter weight 22 is hung up or hung down to the rear end side of the turning frame 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, a hydraulic excavator,
The present invention relates to a counterweight attaching / detaching device for a working machine, which is preferably used for attaching / detaching the counterweight to / from a working machine such as a hydraulic crane to remove the counterweight.

[0002]

2. Description of the Related Art Generally, in working machines such as hydraulic excavators and hydraulic cranes, working devices such as shovels and cranes are provided on the front side of the working machine body, and the working machines are balanced on the rear side of the working machine body. For this reason, a counterweight is detachably provided. Further, a counterweight attaching / detaching device is provided on the rear side of the frame of the working machine body, and when the counterweight is attached to or detached from the rear side of the working machine body, the counterweight is lifted by the counterweight attaching / detaching device. It is configured to be hung.

Therefore, FIGS. 8 to 10 show an example of a counterweight attaching / detaching device for a hydraulic excavator as a counterweight attaching / detaching device for a working machine according to this type of prior art.

In the drawings, 1 is a lower traveling body, 2 is an upper revolving body which constitutes a main body of a working machine mounted on the lower traveling body 1 so as to be revolvable, and the upper revolving body 2 is a revolving frame serving as a frame. A driver's cab 4, a machine room 5 and a counterweight 6 are provided on the counter 3, and the counterweight 6 balances the entire upper revolving structure 2 with respect to a working device 7 described later. Further, a prime mover, a hydraulic pump (neither shown), and the like are provided in the machine room 5.

Reference numeral 7 denotes a working device provided at the front part of the upper swing body 2, and the working device 7 is a boom 8 provided at the front part of the swing frame 3 so as to be able to lift and lower, and a tip end of the boom 8. The arm 9 is provided so as to be able to move up and down, and the backhoe type bucket 10 is provided at the tip side of the arm 9 so as to be rotatable. The boom 8, the arm 9 and the bucket 10 are provided with a boom cylinder 11 , The arm cylinder 12 and the bucket cylinder 13 respectively. Then, the working device 7 rotates the bucket 10 by the bucket cylinder 13 while raising and lowering the boom 8 and the arm 9 by the boom cylinder 11 and the arm cylinder 12 at the time of excavating earth and sand by the bucket 10. Is to be drilled.

Reference numeral 14 denotes an elevating mechanism for a counterweight 6 provided on the revolving frame 3 of the upper revolving structure 2 at the rear side of the machine room 5. The elevating mechanism 14 is, as shown in FIG. The brackets 15A and 15B that are integrally provided on the rear end side, the rotating arm 16 that is rotatably pin-coupled to the upper end side of the bracket 15B via a connecting pin 16A, and the rotating arm 16 It comprises a lifting cylinder 17 which is pin-coupled between the rotating arm 16 and the bracket 15A so as to rotate up and down, and lifts and lowers the counterweight 6, and a connecting pin 16B is provided on the tip side of the rotating arm 16. The counterweight 6 is connected via the connecting tool 18 and the like.

Here, as shown in FIG. 9, the lifting cylinder 17 is fixed to a tube 17A and a piston (not shown) whose base end side is slidably fitted in the tube 17A, and whose tip side is a tube. 17A Rod 17B protruding outside
And the projecting end side of the rod 17B has a rotating arm 1
6 is pin-connected via a connecting pin 17C or the like, and the proximal end side of the tube 17A is pin-connected to the bracket 15A via a connecting pin 17D or the like. Then, the elevating mechanism 14 extends and contracts the rod 17B of the elevating cylinder 17 from the tube 17A, and pivots the pivot arm 16 up and down along an arc a shown by an imaginary line in FIG. The counterweight 6 is hung up or hung down via the connecting tool 18.

In the prior art having such a structure, the lifting mechanism 14 is used to move the counterweight 6 to the swing frame 3
When hoisting to the rear end side, pressure oil is externally supplied to and discharged from the lifting cylinder 17 to extend the rod 17B from the tube 17A, whereby the rotary arm 16 is connected to the connecting pin 16
Rotate upward along an arc a centered on A,
The counterweight 6 placed on the support base 19 and the like is lifted onto the revolving frame 3 as indicated by a phantom line in FIG.

Then, in this state, the counterweight 6 is fixed to the rear side of the revolving frame 3 using a long bolt or the like, and the counterweight 6 balances the entire upper revolving structure 2 with respect to the working device 7 to excavate. It is designed to ensure stability when working.

When the counterweight 6 is loaded and unloaded from the swivel frame 3, pressure oil is discharged from the lifting cylinder 17 with the long bolts or the like for fixing the counterweight 6 removed from the swivel frame 3. 17B
While gradually reducing the inside of the tube 17A, the rotating arm 16 of the elevating mechanism 14 is rotated downward at a slow speed,
The counterweight 6 is slowly suspended from the position shown by the phantom line in FIG. 9 to the position shown by the solid line, and the counterweight 6 is lowered onto the ground G.

Assuming an xy coordinate centering on the base end side (connecting pin 16A) of the rotating arm 16 as shown in FIG. 10, the base end side of the lifting cylinder 17 (connecting pin 1).
7D) becomes coordinates (x1, y1), and the connecting pins 16A,
The dimension L1 between 17D is

[0012]

[Equation 1] Has become.

Further, the length dimension La from the base end of the rotating arm 16 to the tip (between the connecting pins 16A and 16B) is set to La, and from the base end of the rotating arm 16 to the pin connecting portion on the tip side of the rod 17B (connecting. When the dimension Lb between the pins 16A and 17C) is set, the rod 17B of the lifting cylinder 17 is extended with the stroke length S from the most contracted position, and the counterweight 6 is lifted when the counterweight 6 is lifted to the rear end side of the revolving frame 3. The height H1 is

[0014]

[Formula 2] H1 ≈ S × La / Lb, and the hoisting height H1 becomes the stroke length S by multiplying the stroke length S of the rod 17B by the link ratio (La / Lb) of the dimensions La and Lb. On the other hand (L
a / Lb) times the size.

[0015]

By the way, in the above-mentioned prior art, the lifting height H1 is set by extending and retracting the lifting cylinder 17 of the lifting mechanism 14 by the stroke length S.
Since the counterweight 6 is hoisted or hung, the stroke length S of the lifting cylinder 17 is kept constant and the hoisting height H1 is increased from the base end to the tip of the rotary arm 16. The length dimension La between the connecting pins 16A and 16B must be lengthened.

However, when the length dimension La of the rotating arm 16 is increased, the rod 17B of the lifting cylinder 17 is used.
Is greatly extended and the pivot arm 16 is pivoted upward, so that when the counterweight 6 is hung on the pivot frame 3 as indicated by an imaginary line in FIG. ) Side largely protrudes from the upper surface of the counterweight 6, and there arises a problem that the rotating arm 16 interferes with the engine cover of the machine room 5 and other obstacles.

As a result, in the prior art, the rotating arm 16
Since the length La of the can not be increased, the lifting height H1
It becomes difficult to increase the weight of the counterweight 6 and the counterweight 6 cannot be directly loaded and unloaded from the revolving frame 3 onto the ground G. Therefore, the support base 19 having the height H is placed on the ground G, and the counterweight 6 is placed on the ground. Since 6 is loaded and unloaded, there is a problem that the loading and unloading work of the counterweight 6 is troublesome.

The present invention has been made in view of the above-mentioned problems of the prior art. The present invention can surely increase the hoisting height when the counterweight is moved up and down, and can greatly simplify the loading and unloading work of the counterweight. Another object of the present invention is to provide a counterweight attaching / detaching device for a working machine, which is capable of solving the problem that the rotating arm interferes with the engine cover and other obstacles.

[0019]

In order to solve the above problems, the present invention provides a frame of a working machine main body, a counterweight detachably attached to the frame of the working machine main body, and the counterweight on the frame. It is applied to a counterweight attachment / detachment device for a working machine, which comprises an elevating mechanism provided on the frame so as to elevate and lower.

The feature of the construction adopted by the invention as claimed in claim 1 is that the lifting mechanism is connected to a bracket provided on the frame, the base end side is rotatably pin-coupled to the bracket, and the tip side is A rotating arm rotatably connected to the counterweight via a connecting tool, a tip side rotatably pin-coupled to a tip side of the rotating arm, and a base end side rotatably pinned to the bracket. When the counterweight is lifted to the frame side by including a lifting / lowering cylinder coupled to each other, and bringing a pin coupling portion between the lifting / lowering cylinder and the bracket close to a pin coupling portion between the rotating arm and the bracket. When the lifting cylinder is turned upward together with the turning arm and the counterweight is lowered, the lifting cylinder is turned downward together with the turning arm. In that the arrangement for rotating the.

In this case, in the invention according to claim 2, the pin connecting portion between the lifting cylinder and the bracket is arranged below the pin connecting portion between the rotating arm and the bracket, and the lifting and lowering is performed. The cylinder for rotation is rotated upward together with the rotary arm to raise the counterweight to the frame side when the rod is extended, and is rotated downward together with the rotary arm to lower the counterweight when the rod is contracted. I am trying.

According to a third aspect of the present invention, the pin connecting portion between the lifting cylinder and the bracket is disposed above the pin connecting portion between the rotating arm and the bracket, and the lifting cylinder is provided. Is configured to rotate upward together with the rotating arm to raise the counterweight toward the frame when the rod is contracted, and downwardly rotate together with the rotating arm to lower the counterweight when the rod is extended. There is.

Further, a feature of the structure adopted by the invention described in claim 4 is that the elevating mechanism is provided with first and second brackets provided on the frame, and the base end side is rotated to the first bracket. A pivot arm that is movably pin-coupled and whose tip side is rotatably coupled to the counterweight through a coupling tool; and a tip side that is rotatably pin-coupled to the tip side of the pivot arm. A lifting cylinder that is rotatably pin-coupled to the second bracket, and a pin coupling portion between the lifting cylinder and the second bracket is connected to the rotation arm and the first bracket. By bringing the counterweight closer to the pin coupling portion, the lifting cylinder is rotated upward together with the rotation arm when the counterweight is raised to the frame side, and the counterweight is lowered when the counterweight is lowered. The descending cylinder lies in where the structure is rotated downward with the rotation arm.

In the invention according to claim 5, the base end side of the rotating arm is located between the first and second brackets, and the pin is rotatably attached to the first and second brackets. It is configured to be combined.

[0025]

With the above construction, in the invention described in claim 1,
The counterweight is attached to the frame side by pin-connecting the lifting cylinder to the tip end side of the rotating arm, and bringing the pin-connecting portion between the lifting cylinder and the bracket close to the pin-connecting portion between the rotating arm and the bracket. When raising the lifting cylinder, the lifting cylinder can be turned upward together with the turning arm, and when lowering the counterweight, the lifting cylinder can be turned downward together with the turning arm. By making a large rotation together with it, the lifting height of the counterweight can be greatly increased.

According to the second aspect of the invention, the pin connecting portion between the lifting cylinder and the bracket is disposed below and closer to the pin connecting portion between the rotating arm and the bracket. , When the rod of the lifting cylinder is extended, the lifting cylinder can be turned upward together with the turning arm to lift the counterweight to the frame side, and when the rod is contracted, the lifting weight is lifted together with the turning arm. The counter cylinder can be rotated downward to load and unload the counterweight directly on the ground.

On the other hand, according to the third aspect of the present invention, the pin connecting portion between the lifting cylinder and the bracket is arranged closer to the pin connecting portion between the rotating arm and the bracket. When the rod of the lifting / lowering cylinder is contracted, the lifting / lowering cylinder can be turned upward together with the turning arm to lift the counterweight to the frame side, and when the rod is extended, the counterweight is lifted / lowered together with the turning arm. The counterweight can be pivoted downward to load and unload the counterweight directly on the ground.

Further, in the invention described in claim 4, it is possible to obtain substantially the same operation as in the invention described in claim 1, and in the invention described in claim 5, the base end side of the rotating arm is the above-mentioned. By being rotatably pin-coupled to the first and second brackets located between the first and second brackets, the first and second brackets can be shared as a bracket for a rotating arm, The second bracket can rotatably support the base end side of the lifting cylinder.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. In the embodiment, the same components as those of the prior art shown in FIGS. 8 and 9 described above are designated by the same reference numerals, and the description thereof will be omitted.

1 to 4 show the first embodiment of the present invention.

In the figure, reference numeral 21 denotes an abutment plate provided on the rear end side of the swivel frame 3, the abutment plate 21 forming a part of the swivel frame 3, and having a size corresponding to a counterweight 22 described later, the swivel frame 3 has a size. Extending in the width direction (left-right direction). Then, the back surface of the counterweight 22 abuts on the front surface side of the abutting plate 21, and the counterweight 22
Is positioned on the rear end side of the revolving frame 3 via a plurality of long bolts (not shown) and the like.

Reference numeral 22 denotes a counterweight detachably provided on the abutment plate 21 of the revolving frame 3, and the counterweight 22 is the counterweight 6 described in the prior art.
As shown in FIG. 3, a concave portion 22A is formed in the middle portion in the width direction (horizontal direction) on the back side thereof. The concave portion 22A is the counterweight 2
The counterweight 22 is prevented from hitting an elevating mechanism 23, which will be described later, when the abutting plate 21 is abutted with the abutting plate 21, and the elevating mechanism 23 is housed inside.
Further, a pair of mounting plates 22B, 22B are integrally provided on the counterweight 22 on the upper side of the concave portion 22A by using means such as welding or bolts, and each mounting plate 22B is illustrated in FIG. As described above, the pins are coupled to the lower ends of the respective connecting members 29, which will be described later, while being separated leftward and rightward.

Reference numeral 23 denotes a lifting mechanism provided on the rear end side of the revolving frame 3 for lifting and hanging the counterweight 22. The lifting mechanism 23 includes brackets 24 and 25, a rotating arm 26 and a rotating arm 26, which will be described later. Lifting cylinder 31
Etc.

Reference numerals 24 and 24 denote first brackets provided integrally with the abutment plate 21 on the rear end side of the revolving frame 3 by means such as welding, and each bracket 24 is a predetermined plate as shown in FIG. The abutting plate 21 is formed with a large thickness and is symmetrically arranged at a constant interval in the widthwise intermediate portion of the abutting plate 21. The brackets 24 project rearward from the abutment plate 21 and rotatably support the base end side of the rotary arms 26 at a height position close to the lower surface of the revolving frame 3.

Reference numerals 25 and 25 denote second brackets integrally provided on the abutment plate 21 by means such as welding so that the brackets 24 are symmetrical with each other.
5 is formed with a predetermined plate thickness, and is used for the lifting cylinder 31.
While sandwiching the base end side from both left and right sides, each bracket 2
It is arranged so that the base end side of each rotating arm 26 is sandwiched between them. The brackets 25 are attached to the abutment plate 21.
The rear end of the lifting cylinder 31 is rotatably supported while protruding rearward from the bracket 24 and protruding downward from each bracket 24. Further, the brackets 25 rotatably support the base end side of the rotary arms 26 between the brackets 24 and the brackets 24, and form a shared bracket for the rotary arms 26 and the lifting cylinder 31.

26, 26 are brackets 24 on the base end side,
25, and left and right turning arms that are rotatably pin-joined between the brackets 24 and 25 via connecting pins 27. The turning arms 26 are, for example, counterweights. A protrusion portion 26A having a length corresponding to the height dimension of 22 and having a substantially U-shape is integrally formed on the tip side thereof. Then, the protruding portion 26 of each rotating arm 26
A has a pair of left and right connecting members 29 via a connecting pin 28,
29 is rotatably pin-coupled, and each mounting plate 22B of the counterweight 22 is coupled to the lower end side of each coupling tool 29 via each support pin 30.

Further, each connecting tool 29 is connected to the left and right ends of the connecting pin 28 via the adjusting bolt 29A, and each connecting tool 2 is rotated by rotating the adjusting bolt 29A.
9 moves up and down relative to the connecting pin 28 to adjust the height position.

Reference numeral 31 denotes an elevating cylinder for rotating each rotating arm 26 up and down. The elevating cylinder 31 has a tube 31A and a base end side similar to the elevating cylinder 17 described in the prior art. The rod 31B is fixed to a piston (not shown) slidably fitted in the tube 31A and has a rod 31B whose tip end side projects outside the tube 31A. The protruding end side of the rod 31B is disposed on the tip end side of each rotating arm 26 via spacers 32, 32, and can be rotated to the tip end side of each rotating arm 26 by a connecting pin 33 extending in the left-right direction. Pin-coupled.

The base end side of the tube 31A is disposed between the brackets 25 via spacers 34, 34, and is rotatably pin-coupled to each bracket 25 by a connecting pin 35 extending in the left-right direction. . Then, the lifting mechanism 23
Attaches the rod 31B of the lifting cylinder 31 to the tube 31A.
From above and below, and by rotating the rotating arm 26 up and down along an arc b shown by an imaginary line in FIG. 3, the counterweight 22 can be hung up via each connecting tool 29,
It is configured to be hung.

Assuming the xy coordinates around the pin connecting portion (connecting pin 27) between the brackets 24 and 25 and the base end side of each rotating arm 26 as shown in FIG. The position of the pin connecting portion (connecting pin 35) between the base and the base end of the lifting cylinder 31 is the coordinate (x2, y2), and the dimension L2 between the connecting pins 27 and 35 is

[0041]

[Equation 3] Has become.

Then, the connecting pin 3 of the lifting cylinder 31
Reference numeral 5 denotes an angle α shown in FIG. 4 so that the rotation arm 26 is located below the connecting pin 27 and approaches the connecting pin 27.
The connecting pin 1 is arranged within the range (between the line segment m and the line segment n passing through the positions of the connecting pins 27 and 33) and described in the prior art.
This dimension L2 is made significantly smaller than the dimension L1 between 6A and 17D.

Further, even if the length dimension from the base end to the tip of the rotating arm 26 (between the connecting pins 27 and 28) is set to the same dimension La as that of the rotating arm 16 of the prior art, the rotating arm 26 will be described.
The dimension Lc from the pin coupling portion (coupling pin 28) of the coupling tool 29 to the pin coupling portion (coupling pin 33) of the lifting cylinder 31 is very small compared to the dimension La, and the coupling pins 28 and 33 are mutually Approaching Then, the lifting height H2 when the rod 31B of the lifting cylinder 31 is extended from the contracted position with the stroke length S and the counterweight 22 is lifted to the rear end side of the revolving frame 3,
The elevating cylinder 31 moves up almost like the rotating arm 26,
By making a large downward swing, the conventional lifting mechanism 1
It is significantly larger than the lifting height H1 according to No. 4.

In this case, when the elevating cylinder 31 is extended and contracted with the stroke length S, the tip end side (connecting pin 28) of each rotating arm 26 rotates along the arc b about the connecting pin 27. The tip end side (connecting pin 33) of the lifting cylinder 31 rotates along an arc c centered on the connecting pin 27. The arcs b and c at this time are located on a concentric circle centering on the connecting pin 27, and the rotation angle θ1 of the rotation arm 26 and the rotation angle θ2 of the lifting cylinder 31.
And are at almost the same angle.

The counterweight attaching / detaching device of the hydraulic excavator according to the present embodiment has the above-mentioned structure, and its basic operation is not particularly different from that of the prior art.

However, in the present embodiment, the lifting mechanism 23 for raising and lowering the counterweight 22 to the rear end side of the revolving frame 3 is integrally provided on the rear end side of the revolving frame 3 together with the abutment plate 21. , The second bracket 24, 2
5, and a pivot arm 26 whose base end side is pin-connected between the brackets 24 and 25 via each connecting pin 27 and whose front end side is connected to the counterweight 22 via the connecting pin 28 and each connecting tool 29. , A base end side is pin-coupled to each bracket 25 via a connecting pin 35, and a tip end side is pin-coupled to the tip side of each rotating arm 26 via a connecting pin 33. By extending and contracting the rod 31B of the cylinder 31 from the tube 31A, the counterweight 22 is hung or hung on the rear end side of the revolving frame 3.
The following operational effects can be obtained.

That is, the pin coupling portion (coupling pin 35) between each bracket 25 and the base end side of the lifting cylinder 31 is connected to the pin coupling portion (coupling pin) between each bracket 24, 25 and the proximal end side of each rotating arm 26. The pin 27) is brought close to the pin 27) with a dimension L2 as shown in FIG. 4, and the pin connecting portion (connecting pin 33) with the lifting cylinder 31 is connected with the connecting tool 29 (connecting pin) on the tip side of each rotating arm 26. 28), when the counterweight 22 is raised and lowered, the raising and lowering cylinder 31 can be pivoted up and down substantially similarly to the pivoting arms 26.

Then, the rod 31 of the lifting cylinder 31
When B is extended from the contracted position with the stroke length S, the lifting cylinder 31 can be largely pivoted upward substantially like each pivot arm 26, and when the counterweight 22 is lifted to the rear end side of the revolving frame 3. Lifting height H
2 can be made significantly larger than the lifting height H1 of the lifting mechanism 14 according to the prior art. In addition, in this state,
As shown in FIG. 5, the tip (upper end) side of each rotating arm 26 does not jump out from the upper surface of the counterweight 22, and the entire lifting mechanism 23 can be housed in the recess 22A of the counterweight 22 almost completely. .

On the other hand, the rod 31B of the lifting cylinder 31
Is contracted from the extended position shown in FIG. 1 as shown in FIG.
When the counterweight 22 is loaded and unloaded from the rear end side of the revolving frame 3 onto the ground G, the lifting cylinder 31 can be largely pivoted downward substantially like each pivot arm 26, and the counterweight 22 can be lifted by the lifting height H2. By greatly descending, the counterweight 22 can be directly loaded and unloaded onto the ground G from the rear end side of the revolving frame 3.

Therefore, in this embodiment, the hoisting height H2 when the counterweight 22 is lifted and lowered can be made significantly larger than the hoisting height H1 of the lifting mechanism 14 according to the prior art, so that the counterweight 22 is swung. When lowering the frame 3 to the ground G or the like, it is not necessary to use the support base 19 unlike the prior art, the loading and unloading work of the counterweight 22 can be simplified, and the workability can be greatly improved.

Further, when the counterweight 22 is lifted to the rear end side of the revolving frame 3, the tip (upper end) side of each rotating arm 26 does not protrude from the upper surface of the counterweight 22, and the counterweight 22 has a concave shape. Since the entire lifting mechanism 23 can be accommodated almost completely in the recess 22A, it is possible to eliminate the problem that the rotating arm 26 interferes with the engine cover of the machine room 5 and other obstacles, and to prevent soil and sand. The entire lifting mechanism 23 can be protected by the counterweight 22 during excavation work, and safety and reliability can be reliably improved.

Furthermore, the first and second brackets 24 and 25 of the lifting mechanism 23 are replaced with the bracket 15 described in the prior art.
It is not necessary to stand up to a high position of the revolving frame 3 as shown in B, and each of the brackets 24 and 25 can be miniaturized and can be accommodated almost completely in the concave portion 22A of the counterweight 22, thus saving space. As a result, various effects can be obtained such that the whole can be made compact.

Next, FIGS. 5 and 6 show a second embodiment of the present invention. The feature of this embodiment is that the counterweight is raised and the counterweight is lowered when the lifting cylinder is contracted. Occasionally, the lifting cylinder is extended. In this embodiment, the first
The same components as those of the embodiment are given the same reference numerals and the description thereof will be omitted.

In the figure, reference numeral 41 denotes an abutment plate provided on the rear end side of the revolving frame 3, and the abutment plate 41 is constructed in substantially the same manner as the abutment plate 21 described in the first embodiment,
A recess (not shown) is formed in the abutting plate 41 at the center in the width direction and extends vertically. Further, each recess 45 of the abutting plate 41 is integrally provided on the bottom side thereof with each bracket 45 described below, and allows a lift cylinder 46 described below to rotate up and down.

Reference numeral 42 denotes an elevating mechanism provided on the rear end side of the revolving frame 3 for hoisting and hanging the counterweight 22. The elevating mechanism 42 corresponds to the elevating mechanism 23 described in the first embodiment. The rotating arm 26, the connecting members 29, and the like have substantially the same structure, and have the same structure.

Reference numerals 43 and 43 denote first brackets (only one of which is shown) integrally provided on the rear end side of the revolving frame 3 together with the abutment plate 41 by means such as welding. The brackets 24 have substantially the same structure as the brackets 24 described in the above embodiment, and are symmetrically arranged at a constant interval so as to sandwich the recess in the widthwise intermediate portion of the abutting plate 41. The brackets 43 project rearward from the abutment plate 41 and rotatably support the base end side of the rotating arms 26 via the connecting pins 44.

Reference numerals 45, 45 are second brackets (only one is shown) integrally provided in the recess of the abutment plate 41 by means such as welding so as to be symmetrical between the brackets 43.
Each of the brackets 45 is formed with a predetermined plate thickness, and is arranged so as to sandwich the base end side of the lifting cylinder 46 from both the left and right sides. And each of the brackets 45
Is disposed in the height direction intermediate portion in the recess of the abutment plate 41, and rotatably supports the base end side of the lifting cylinder 46 in the recess.

Reference numeral 46 denotes an elevating cylinder for rotating each of the rotating arms 26 up and down. The elevating cylinder 46 is similar to the elevating cylinder 31 described in the first embodiment, and the tubes 46A and The rod 46B is configured by a rod 46B and the like, and the protruding end side of the rod 46B is rotatably pin-coupled to the tip end side of each rotating arm 26 via a connecting pin 47. Further, the base end side of the tube 46A is inserted into the recess of the abutting plate 41, and each of the brackets 4 is connected by the connecting pin 48.
5 is rotatably pin-coupled. Then, the lifting mechanism 42 connects the rod 46B of the lifting cylinder 46 to the tube 4
By extending and contracting from 6A and rotating the rotating arm 26 up and down along an arc d shown by an imaginary line in FIG.
The counterweight 22 is hung up or hung down via each connecting tool 29.

Assuming the xy coordinates around the pin connecting portion (connecting pin 44) between each bracket 43 and the base end side of each rotating arm 26 as shown in FIG. The position of the pin connecting portion (connecting pin 48) with the base end side of the working cylinder 46 becomes coordinates (x3, y3),
The dimension L3 between the connecting pins 44 and 48 is

[0060]

[Equation 4] Has become.

Then, the connecting pin 4 of the lifting cylinder 46
Reference numeral 8 indicates the angle β shown in FIG. 6 so as to approach the connecting pin 44 above the connecting pin 44 of the rotating arm 26.
The connecting pin 1 is arranged within the range (between the line segment p and the line segment q passing through the positions of the connecting pins 44 and 47) and described in the prior art.
This dimension L3 is made significantly smaller than the dimension L1 between 6A and 17D.

Further, even if the length dimension from the base end to the tip end (between the connecting pins 44 and 28) of the rotating arm 26 is set to the same dimension La as that of the rotating arm 16 of the prior art, the rotating arm 26 will be described.
The dimension Lc from the pin coupling portion of the coupling tool 29 (the coupling pin 28) to the pin coupling portion of the lifting cylinder 46 (the coupling pin 47) is very small compared to the dimension La, and the coupling pins 28 and 47 are mutually connected. Approaching Then, the lifting height H3 when the rod 46B of the lifting cylinder 46 is extended from the contracted position with the stroke length S and the counterweight 22 is lifted to the rear end side of the revolving frame 3,
The elevating cylinder 46 moves up almost like the rotating arm 26,
By making a large downward swing, the conventional lifting mechanism 1
It is significantly larger than the lifting height H1 according to No. 4.

In this case, when the elevating cylinder 46 is extended and contracted with the stroke length S, the tip end side (connecting pin 28) of each rotating arm 26 is rotated along the arc d about the connecting pin 44. The tip end side (connecting pin 47) of the lifting cylinder 46 rotates along an arc e centered on the connecting pin 44. The arcs d and e at this time are located on a concentric circle centered on the connecting pin 44, and the rotation angle θ3 of the rotation arm 26 and the rotation angle θ4 of the lifting cylinder 46.
And are at almost the same angle.

Thus, in this embodiment having the above-described structure, it is possible to obtain substantially the same operational effect as that of the first embodiment. However, particularly in this embodiment, the counterweight 2 is used.
When 2 is lifted to the rear end side of the revolving frame 3, the rod 46B of the lifting / lowering cylinder 46 is contracted from the extended position with the stroke length S, so that the lifting / lowering cylinder 46 is moved upwards in substantially the same manner as the rotating arms 26. It can rotate greatly. Further, when the counterweight 22 is loaded and unloaded from the rear end side of the revolving frame 3, the lifting cylinder 4
By extending the rod 46B of No. 6 from the contracted position, the lifting cylinder 46 can be largely rotated downward similarly to each rotating arm 26.

In the first embodiment, the base end side of the rotating arm 26 is arranged between the first and second brackets 24 and 25, and the rotating arm 26 can be rotated by the connecting pin 27. However, instead of this, as in the modified example shown in FIG. 7, for example, the proximal end side of the rotating arm 26 is rotatably connected to the bracket 25 using the connecting pin 27 ', The bracket 24 may be omitted.

In each of the above-described embodiments, the pivot arm 26 is rotatably supported by the first bracket 24 (43), and the lifting cylinder 31 (46) is supported by the second bracket 25 (45). Although it has been described that the brackets 24, 25 (43, 45) are rotatably supported and are configured by separate members, respectively, the present invention is not limited to this. For example, the first and second brackets may be provided. It may be configured by the same member, and the base end side of the rotating arm 26 and the base end side of the lifting cylinder 31 (46) may be pin-connected at different positions with respect to a single bracket member.

On the other hand, in the first embodiment, the connecting pin 35 of the lifting cylinder 31 is connected to the connecting pin 2 of the rotating arm 26.
Although it has been described that the connecting pin 27 is located closer to the lower side than 7, and the distance between the connecting pins 27 and 35 is set to the dimension L2, the present invention is not limited to this, and the lifting cylinder 31 is used.
4 may be arranged at any position within an angle α (between the line segment m and the line segment n passing through the positions of the connection pins 27 and 28) shown in FIG. Cylinder 31
It suffices to bring the connecting pin 35 close to the connecting pin 27 within a range in which does not contact the connecting pin 27.

The connecting pin 48 described in the second embodiment is also used.
6 may be arranged at any position within the range of the angle β (between the line segment p and the line segment q passing through the positions of the connecting pins 44 and 28) shown in FIG. 46
The connecting pin 48 may be brought close to the connecting pin 44 within a range in which does not contact the connecting pin 44.

Further, in each of the above-mentioned embodiments, the pair of rotating arms 26, is provided on both the left and right sides of the lifting cylinder 31 (46).
The lifting mechanism 23 (42) provided with 26 has been described as an example, but instead of this, a pair of lifting cylinders may be provided on the left and right sides of one rotating arm. Good. In addition, the connector 2 provided with the adjusting bolt 29A
Instead of 9, a cord such as a wire or a rope may be used as a connecting tool.

Furthermore, in each of the above-described embodiments, the counterweight attaching / detaching device of the hydraulic excavator has been described as an example, but the present invention is not limited to this, and the counterweight attaching / detaching device of various working machines such as a hydraulic crane, for example. Can also be applied to.

[0071]

As described in detail above, according to the invention of claim 1, the lifting cylinder is pin-coupled to the tip end side of the rotating arm, and the pin coupling portion between the lifting cylinder and the bracket is By bringing the counterweight closer to the pin coupling portion between the rotating arm and the bracket, the lifting cylinder is rotated upward together with the rotating arm when the counterweight is raised toward the frame side, and the lifting cylinder is lowered when the counterweight is lowered. Since the cylinder is rotated downward together with the rotating arm, the hoisting height when the counterweight is raised and lowered can be surely increased, and the loading and unloading work of the counterweight can be greatly simplified.
Further, since the rotating arm and the lifting cylinder are prevented from popping out from the upper surface of the counterweight, it is possible to improve the aesthetics and eliminate the work of removing an extra link and the like. Problems such as interference with obstacles can be eliminated.

According to the second aspect of the present invention, the pin connecting portion between the lifting cylinder and the bracket is disposed closer to and below the pin connecting portion between the rotating arm and the bracket. , When the rod of the lifting / lowering cylinder is extended, the lifting / lowering cylinder can be pivoted largely together with the pivot arm to lift the counterweight to the frame side, and when the rod is contracted, the counterweight is pivoted. The counterweight can be greatly rotated downward together with the arm to load and unload the counterweight directly on the ground, and workability can be greatly improved.

On the other hand, according to the third aspect of the present invention, the pin connecting portion between the lifting cylinder and the bracket is arranged closer to the pin connecting portion between the rotating arm and the bracket. When the rod of the lifting / lowering cylinder is contracted, the lifting / lowering cylinder can be largely rotated upward together with the rotating arm, and when the rod is extended, the lifting / lowering cylinder can be largely rotated downward together with the rotating arm. The counterweight can be directly loaded and unloaded on the ground, and the workability in raising and lowering the counterweight can be greatly improved.

Further, in the invention described in claim 4, substantially the same effect as that of the invention described in claim 1 can be obtained, and in the invention described in claim 5, the first and second inventions are provided. The bracket can be commonly used as a bracket for the rotating arm, and the second bracket can rotatably support the base end side of the lifting cylinder, so that the number of brackets can be reduced and the first and second brackets can be used. The bracket can be formed of the same member, and the base end side of the rotating arm and the base end side of the lifting cylinder can be rotatably pin-coupled to the single bracket member at different positions. it can.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a counterweight attaching / detaching device for a hydraulic excavator according to a first embodiment of the present invention, taken along line I-I in FIG.

FIG. 2 is a front view of the counterweight attaching / detaching device shown in FIG.

FIG. 3 is a vertical sectional view similar to FIG. 1, showing a state in which counterweights are loaded and unloaded on the ground.

FIG. 4 is an operation explanatory view of the rotating arm, the lifting cylinder, and the like shown in FIG.

FIG. 5 is a vertical sectional view similar to FIG. 3, showing a counterweight attaching / detaching device for a hydraulic excavator according to a second embodiment.

FIG. 6 is an operation explanatory view of the rotating arm, the lifting cylinder, and the like shown in FIG.

FIG. 7 is a front view similar to FIG. 2, showing a counterweight attaching / detaching device according to a modification.

FIG. 8 is an overall view showing a hydraulic excavator according to a conventional technique.

FIG. 9 is a partially cutaway external view showing a counterweight attaching / detaching device of the related art.

10 is an operation explanatory view of the rotating arm, the lifting cylinder, and the like shown in FIG.

[Explanation of symbols]

1 Lower Traveling Body 2 Upper Revolving Body (Work Machine Main Body) 3 Revolving Frame (Frame) 5 Machine Room 7 Working Device 21,41 Abutting Plate 22 Counterweight 23,42 Lifting Mechanism 24, 25, 43, 45 Bracket 26 Rotating Arm 27, 27 ', 28, 33, 35, 44, 47, 48
Connecting pin (pin connecting part) 29 Connecting tool 31,46 Lifting cylinder 31A, 46A Tube 31B, 46B Rod

Claims (5)

[Claims] 1. A frame of a working machine main body, a counterweight removably provided on the frame of the working machine main body, and an elevating mechanism provided on the frame for elevating the counterweight on the frame. In the counterweight attaching / detaching device for a working machine, the lifting mechanism is pivotally pinned to a bracket provided on the frame, the base end side of which is pivotally connected to the bracket, and the tip end side of which is pivoted to the counterweight via a connector. A pivoting arm movably connected to the pivoting arm, and a lifting cylinder pivotally connected to the tip end of the pivoting arm by a pivotal pin and pivotally pinned to the bracket at the proximal end. By bringing the pin connecting portion between the lifting cylinder and the bracket close to the pin connecting portion between the rotating arm and the bracket, the counter weight is flared. When raising to the arm side, the lifting cylinder is turned upward together with the turning arm,
A counterweight attaching / detaching device for a working machine, wherein the lifting cylinder is configured to rotate downward together with a rotating arm when lowering the counterweight. 2. The pin connecting portion between the lifting cylinder and the bracket is disposed below the pin connecting portion between the rotating arm and the bracket, and the lifting cylinder rotates when the rod extends. The working machine according to claim 1, wherein the counterweight is rotated upward together with the arm to raise the counterweight to the frame side, and when the rod is contracted, the counterweight is rotated downward together with the rotating arm to lower the counterweight. Counterweight desorption device. 3. The pin coupling portion between the lifting cylinder and the bracket is disposed above the pin coupling portion between the rotating arm and the bracket, and the lifting cylinder is configured to rotate the rotating arm when the rod is contracted. 2. The working machine according to claim 1, wherein the counterweight is rotated upward together with the counterweight to raise it toward the frame, and when the rod is extended, the counterweight is rotated downward together with the rotating arm to lower the counterweight. Counterweight desorption device. 4. A frame of a working machine main body, a counterweight removably provided on the frame of the working machine main body, and an elevating mechanism provided on the frame for elevating the counterweight on the frame. In a counterweight attaching / detaching device for a working machine, the elevating mechanism has first and second brackets provided on the frame, and a base end side of which is rotatably pin-coupled to the first bracket.
A rotating arm whose front end side is rotatably connected to the counterweight via a connecting tool, a front end side being rotatably pin-connected to the front end side of the rotating arm, and a base end side of the second bracket. A lifting cylinder that is rotatably pin-coupled, and a pin coupling portion between the lifting cylinder and the second bracket is brought close to a pin coupling portion between the rotation arm and the first bracket, When the counterweight is raised to the frame side, the lifting cylinder is turned upward together with the turning arm, and when the counterweight is lowered, the lifting cylinder is turned downward together with the turning arm. Counterweight attachment / detachment device for working machines. 5. The base of the rotating arm is located between the first and second brackets and is rotatably pin-coupled to the first and second brackets. Work machine counterweight desorption device.