JPS621328Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a retractable boom for an excavator. In the past, various types of extendable booms have been proposed in which the length of the boom is increased using a hydraulic cylinder, etc., in order to deepen the depth of grooves, holes, etc. that can be dug with a single excavator. However, they all have the disadvantage of being expensive to produce.

In order to provide a telescopic boom at a low cost, the present invention consists of a boom for an excavator consisting of an intermediate boom and a telescopic boom slidably fitted into the intermediate boom. A connecting rod that is fixed to the intermediate boom with a set pin in the adjustment position and that pivotally connects the piston rod of the hydraulic cylinder for bucket operation mounted on the intermediate boom and the back of the bucket that is pivotally attached to the tip of the telescopic boom. Each time the telescopic boom is adjusted, it is replaced with a length corresponding to the adjusted length.

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. In the figure, reference numeral 1 denotes an extendable boom for an excavator, which is composed of an intermediate boom 2 and an extendable boom 3 slidably fitted into the intermediate boom 2. At the base of the intermediate boom 2, a bucket operating hydraulic cylinder 5 equipped with a piston rod 4 is swingably mounted on a mounting shaft 6. At the tip of the intermediate boom 2, there are 1
A pair of set pin insertion holes 7 and 8 are provided. The telescopic boom 3 is provided with two pairs of adjustment holes 9 and 10 and 11 and 12 in the longitudinal direction, and the interval between each pair of adjustment holes is the same as the interval between the set pin insertion holes 7 and 8. be. Buckets 1 are attached to both ends of the pivot shaft 13 that protrudes from both sides of the tip of the telescopic boom 3.
Bearings 15, 15 on both sides of the rear edge of 4 are pivotally connected. Reference numeral 16 denotes a set pin which also serves as a pivot, and is adapted to be removably attached to the set pin insertion hole 7 and the adjustment hole 9 or 11 selectively facing the hole 7. Reference numeral 17 denotes a set pin, which is removably attached to the set pin insertion hole 8 and the adjustment hole 10 or 12 selectively facing the hole 8. The bases of the links 18, 18 are pivotally connected to both ends of a set pin 16 which also functions as a pivot joint and which protrudes from both sides of the tip of the intermediate boom 2.
A connecting pin 19 is removably attached to the tip of 18. The hydraulic cylinder 5 is connected to the connecting pin 19.
The tip of the piston rod 4 is pivotally connected,
When the hydraulic cylinder 5 is actuated, the piston rod 4
The links 18, 18 are adapted to rotate around the set pin 16, which also serves as a pivot joint, through the connecting pin 19 and the connecting pin 19. Bearing part 2 at the center of the back of bucket 14
0 and 20, pivot pins 21 are removably attached. Reference numerals 22 and 23 are exchangeable connecting rods having different lengths, and each time the telescopic boom 3 is adjusted, either end of the connecting rods 22 and 23 is connected to the connecting pin 19 depending on the length of the adjustment. and a pivot pin 21. 24,
24 is an auxiliary link pivotally connected to the pivot shaft 13 and the pivot pin 21. Auxiliary link 24 and link 1
8, and the lengths of the connecting rods 22 and 23 are such that when the hydraulic cylinder 5 is actuated, the auxiliary link 24 remains parallel to the link 18 and rotates around the pivot shaft 13. It is designed to. 25,
26 are mounting holes, respectively. Although the drawing shows an embodiment with two pairs of adjusting holes and two connecting rods, it goes without saying that the number of pairs of adjusting holes and the number of connecting rods may be increased as appropriate. .

The extendable and retractable boom for an excavator of the present invention is constructed as described above, and the mounting hole 25 is attached to the tip of the main boom of the excavator using the pivot shaft, and the mounting hole 26 is attached to the tip of the main boom of the excavator. It is attached to the tip of the piston rod of the hydraulic cylinder for boom operation using a pivot shaft. During normal excavation, as shown in FIG. 1, the telescopic boom 3 is fitted into the intermediate boom 2 at its deepest position, and the boom 1 is at its shortest position. When the hydraulic cylinder 5 is actuated to reciprocate the piston rod 4, the link 18,
Reference numeral 18 reciprocates around a set pin 16 which also serves as a pivot. At the same time, the connecting pin 19 and the connecting rod 2
2 and the auxiliary link 24, 2 via the pivot pin 21.
4 is kept parallel to the links 18, 18 and reciprocated around the pivot shaft 13, and the bucket 14 is reciprocated around the pivot shaft 13, thereby making it possible to carry out excavation work. It is. To increase the length of the boom 1, remove the pivot set pin 16, set bin 17, connection pin 19, pivot pin 21, and connection rod 22 in FIG. 1, and then remove the telescopic boom 3 as shown in FIG. As shown in the figure, pull out the intermediate boom 2 from inside and attach the connecting rod 22 to the connecting rod 2.
After replacing the pins 16, 17, 19,
21 is attached as shown in FIG. After adjusting the telescopic boom 3, link 18
Since the auxiliary link 24 is parallel to the auxiliary link 24, digging can be performed in the same manner as before adjustment.

As is clear from the above description, the present invention comprises a boom for an excavator including an intermediate boom and a telescoping boom slidably fitted into the intermediate boom. A connecting rod that is fixed to the intermediate boom with a set pin in the adjustment position and that pivotally connects the piston rod of the hydraulic cylinder for bucket operation mounted on the intermediate boom and the back of the bucket that is pivotally attached to the tip of the telescopic boom. Each time the telescoping boom is adjusted, it is replaced with a length corresponding to the adjustment length, and a hydraulic cylinder is not used to adjust the length of the boom, so the structure is To provide a boom for an excavator that is simple and easy to manufacture, is extendable and retractable at low cost, and allows the length of the boom to be adjusted without being affected by failure of a hydraulic system. Furthermore, in the present invention, when adjusting the length of the boom, the connecting rod is replaced and the bucket is operated by a parallel link mechanism both before and after adjusting the length of the boom. Therefore, the excavation work can be carried out smoothly regardless of the adjustment of the boom.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a partially cutaway side view showing the normal state, Fig. 2 is a partially cutaway side view showing the extended state, and Fig. 3 shows the main parts. The perspective view and FIG. 4 are cross-sectional views taken along line A-A in FIG. 1. 1...Boom for excavator, 2...Intermediate boom, 3
...Telescopic boom, 4...Piston rod, 5...
... Hydraulic cylinder, 6 ... Mounting shaft, 7, 8 ... Set pin insertion hole, 9, 10, 11, 12 ... Adjustment hole, 13 ... Pivot shaft, 14 ... Bucket, 15
... Bearing part, 16 ... Pivot combination set pin, 17
... Set pin, 18 ... Link, 19 ... Connection pin, 20 ... Bearing section, 21 ... Pivot pin, 2
2, 23...Connection rod, 24...Auxiliary link,
25, 26...Mounting holes.

Claims (1)

[Scope of utility model registration request] A boom for an excavator is composed of an intermediate boom and a telescopic boom slidably fitted into the intermediate boom, and a hydraulic cylinder for bucket operation is attached to the base of the intermediate boom, and a hydraulic cylinder for bucket operation is attached to the base of the intermediate boom. is provided with a pair of set pin insertion holes at intervals in the longitudinal direction, and the telescoping boom is provided with a plurality of pairs of adjustment holes with the same spacing as the pair of set pin insertion holes, and a distal end thereof. A bucket belt is rotatably pivotally mounted on both sides of the bucket belt, and a pivot-mounted set pin and a set pin are removably mounted in the pair of set pin insertion holes and any one pair of adjustment holes,
The base of the link is pivotally connected to both sides of the intermediate boom by the pivot and set pin, and the connecting pin removably attached to the tip of the link connects the tip of the piston rod of the hydraulic cylinder to one end of the connecting rod. The other end of the connecting rod is pivotally connected with a pivot pin removably attached to the central part of the back of the bucket, and the connecting rod is adjusted according to the adjustable length of the telescopic boom. An extendable boom for a digging machine, characterized in that it can be exchanged for a longer boom.