JPH0350141Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a double-opening gripping fork device used as an attachment for a power shovel.

(Prior art) As a conventional double-opening type grasping fork device of this type, there is a Japanese Utility Model Application No. 61-49779 filed by the present applicant.
A device described in the above publication is known.

In this conventional device, as a structure for synchronizing the opening and closing of both gripping forks, a sliding guide groove is formed along the opening/closing center line of both gripping forks in the base part, and a slider is inserted into the sliding guide groove. was provided in a slidable manner, and the slider and points on the inside of the pivot points of both gripping forks were rotatably connected by synchronized links.

In addition, with the above-mentioned tuning structure, there is no risk of an inoperable state due to tooth loss or foreign matter getting caught, unlike in conventional gear type tuning structures.
Moreover, since only compressive or tensile loads are applied to the tuning link in its longitudinal direction, there is no bending or deformation of the tuning link, resulting in a simple structure and high durability. There are advantages.

(Problems to be solved by the invention) However, it has been found that the conventional tuning structure also has the following problems.

That is, in the conventional tuning structure, compressive stress acting on one tuning link and tensile stress acting on the other tuning link cause the slider to pull toward the tuning link side in the sliding guide groove. Since the slide is strongly pressed against the sliding surface of the slider, there is a problem in that the sliding surface on the pressing side is likely to wear out and cause backlash. However, it is necessary to use a thick steel plate to provide sufficient strength to the base, which increases the weight of the device and increases costs.

(Means for solving the problems) The present invention was made with the aim of solving the problems of the conventional device as described above. It is equipped with a base section that is removably attached to the tip, and a pair of front and rear gripping forks that are separately pivotally supported on the tip side of the base section, and a hydraulic cylinder is connected to one of the gripping forks via a push rod. A double-opening gripping fork device in which the piston rods of the gripping forks are connected to each other, and an opening/closing synchronization means is interposed between both gripping forks, and the opening/closing tuning means is freely moved approximately along the opening/closing center line of both gripping forks. A rotating arm is pivotally supported on the base so that the end side thereof can rotate, and one end is pivotally supported on the free end side of the rotating arm, and the other end is attached to the inner side of the pivot point of each gripping fork. It consists of two tuning links each pivoted at a point.

(Function) In the gripping fork device for a power shovel of the present invention, as described above, the opening/closing adjustment means of both gripping forks are mounted on the base so that the free end side rotates approximately along the opening/closing center line of both gripping forks. A pivotally supported rotating arm, and two synchronizers each having one end pivoted on the free end side of the pivoting arm and the other end pivoted at a point inside the pivot point of each gripping fork. By composing the synchronizing link with the piston rod of the hydraulic cylinder via the push rod, a compressive load acts on the synchronized link on the gripping fork side in its longitudinal direction, and the load on the other gripping fork side Only a tensile load is applied to the tuning link in the longitudinal direction, and therefore, no excessive force such as bending or deformation is applied to the tuning link, resulting in excellent durability. Become.

In addition, instead of using a sliding guide groove and a slider, a rotating arm is used to swingly support the shaft support between both tuning links, which prevents play from occurring due to wear and tear on the sliding parts. At the same time, there is no need to reinforce the base to create a sliding guide groove.
Accordingly, it is possible to reduce the weight and cost of the device.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

First, the configuration of the embodiment will be explained.

As shown in FIGS. 1 and 2, the gripping fork device A for a power shovel according to this embodiment mainly includes a base portion 1, a pair of front and rear gripping forks 2, 3, and opening/closing synchronization means 4. ing.

The base part 1 serves as a mounting base part for removably attaching the gripping fork device A in place of the bucket of the power shovel. a connecting plate 1b that connects the mounting plates at both front and rear edges;
1b, and on the front edge side of both mounting plates 1a, 1a, there is a shaft hole 1 for connecting with the tip of the intermediate boom 5 of the power shovel inserted.
0 and 11 have been established.

The pair of front and rear gripping forks 2 and 3 are provided facing each other on the tip side (lower end side) of the base portion 1, and in this embodiment, each of the gripping forks 2 and 3
The base side of the front gripping fork 2 is formed to be wide in the front and rear direction, and the front end of the front gripping fork 2 and the rear end of the rear gripping fork 3 are connected to pivot shafts 20 and 30 on both front and rear sides of the lower end of the base portion 1, respectively. It is rotatably supported on the shaft.

In this embodiment, the front gripping fork 2
has two claws in parallel, and rear gripping fork 3 has three claws.
The books are arranged side by side.

In addition, on the outer surface of the middle part of the front gripping fork 2,
A bearing piece 21 for rotatably connecting the tip side of the push rod 61 is provided in a protruding shape.

The opening/closing synchronizing means 4 is a means for synchronizing the gripping forks 2 and 3 so as to open and close them at approximately the same opening angle in the front and rear directions around the opening/closing center line m thereof, and includes a rotating arm 40 and a rotating arm 40. , and two tuning links 41 and 42.

The rotating arm 40 has both gripping forks 2 and 3.
Its base side is pivotally supported by the base part 1 so that its free end side can rotate approximately along the opening/closing center line m, and in this embodiment, the rear connecting plate 1b
The base side of the rotating arm 40 is rotatably supported by bearing pieces 12, 12 protruding from both sides of the opening with a pivot 40a.

Further, the two tuning links 41 and 42 are links for connecting both the gripping forks 2 and 3, and in this embodiment, one pivot shaft 40b provided on the free end side of the rotating arm 40 Its upper end side is pivotally supported, and its lower end side is supported by the base side rear end of the front gripping fork 2 and the rear gripping fork 3.
The front end of the proximal side is separately supported by pivots 41a and 42a, respectively.

Next, the operation of this embodiment will be explained.

Since this embodiment has the above configuration, the tip of the intermediate boom 5 with the bucket removed is inserted between the left and right mounting plates 1a, 1a of the base 1, and the shaft holes 50, 51 of the intermediate boom 5 and the base 1 shaft hole 10,1
1 and the piston rod 60 in the hydraulic cylinder 6.
A strap 62 is interposed between the tip of the piston rod 60 and the inner bolt/nut 7, and the tip of the piston rod 60 and the bearing piece 21 of the front gripping fork 2 are rotatably connected by a push rod 61. The hydraulic cylinder 6 is interlocked with the hydraulic cylinder 6.

Therefore, when the hydraulic cylinder 6 is operated in the pulling direction, the push rod 61 is moved as shown in FIG.
As the front gripping fork 2 moves upward, it rotates clockwise forward about its pivot, and at the same time, the pivot 41a that pivotally supports the front tuning link 41 rotates downward clockwise about the pivot 20. The downward pulling action of the front tuning link 41 caused by this rotation causes the free end side of the rotating arm 40 to rotate downward in the counterclockwise direction. Supported rear tuning link 4
Due to the downward pushing action of 2, the pivot 42a and the rear gripping fork 3 rotate rearward and counterclockwise around the pivot 30, so that both the front and rear gripping forks 2 and 3 are synchronized. It will open both front and back at the same time.

Next, when the hydraulic cylinder 6 is operated in the pushing direction, as shown in FIG. It is activated, and rocks etc. can be held between both gripping forks 2 and 3.

As explained above, in the gripping fork device A for a power shovel according to the present embodiment, as described above, the opening/closing tuning means 4 of both gripping forks 2 and 3 is
A rotating arm 40 is pivotally supported on the base part 1 so that the free end side rotates approximately along the opening/closing center line m of both gripping forks 2 and 3, and a rotating arm 40 is attached to the free end side of the rotating arm 40. It is composed of two synchronized links 41 and 42, each of which has one end pivoted and the other end pivoted at a point inside the pivots 20 and 30 that serve as pivot points for each gripping fork 2 and 3. As a result, a compressive load acts on the tuning link 41 on the side of the gripping fork 2 connected to the piston rod 60 of the hydraulic cylinder 6 via the push rod 61 in the longitudinal direction, and a load on the side of the other gripping fork 3 is applied. Only a tensile load is applied to the tuning link 42 in its longitudinal direction, and therefore, no excessive force such as bending or deformation is applied to the tuning links 41 and 42, which improves durability. It will be excellent.

In addition, by using the rotating arm 40 instead of the sliding guide groove and the slider to slidably support the shaft support between the two tuning links 41 and 42, the occurrence of backlash due to wear and tear of the swinging part can be avoided. In addition, it becomes unnecessary to reinforce the base portion 1 to create the sliding guide groove, and the weight and cost of the device can be reduced accordingly.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention may be modified without departing from the gist of the present invention. include.

For example, in the embodiment, the upper end side of both tuning links is
Although the case is shown in which the free end side of the rotating arm is pivotally supported by the pivot of the book, it may be pivoted separately.

Further, the shape and number of claws of each gripping fork are also arbitrary.

(Effect of the invention) As explained above, in the gripping fork device for a power shovel of the invention, the opening/closing synchronization means of both gripping forks is rotated on the free end side approximately along the opening/closing center line of both gripping forks. As shown in FIG. By constructing the synchronization link with two synchronized links, a compressive load acts on the synchronization link on the gripping fork side, which connects the piston rod of the hydraulic cylinder via the push rod, in the longitudinal direction. , only a tensile load is applied to the tuning link on the other gripping fork side in its longitudinal direction, and therefore, no excessive force such as bending or deformation is applied to the tuning link, and the durability is improved. Becomes excellent in sex.

In addition, instead of using a sliding guide groove and a slider, a rotating arm is used to swingly support the shaft support between both tuning links, which prevents play from occurring due to wear and tear on the sliding parts. At the same time, there is no need to reinforce the base to create a sliding guide groove.
Effects such as making it possible to reduce the weight and cost of the device accordingly can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a gripping fork device for a power shovel according to an embodiment of the present invention in an open state, and FIG. 2 is a side view showing the same in a closed state. 1: Base part, 2: Front gripping fork, 3: Rear gripping fork, 4: Opening/closing synchronization means, 5: Intermediate boom, 6: Hydraulic cylinder, 40: Rotating arm, 4
1: Front tuning link, 42: Back tuning link,
m: Opening/closing center line.

Claims (1)

[Claims for Utility Model Registration] A power shovel comprising a base section that is removably attached to the tip of an intermediate boom, and a pair of front and rear gripping forks that are separately pivotally supported on the tip side of the base section, A double-opening gripping fork device in which a piston rod of a hydraulic cylinder is connected to one of the gripping forks via a push rod, and an opening/closing synchronization means is interposed between both gripping forks, the opening/closing tuning means being interposed between the two gripping forks. , a rotating arm pivotally supported on a base so that the free end side rotates substantially along the opening/closing center line of the both gripping forks, and one end pivotally supported on the free end side of the rotating arm, and A gripping fork device for a power shovel, characterized in that the gripping fork device comprises two synchronized links each having the other end pivotally supported at a point inside the pivot point of each gripping fork.