JPS632879B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an extension/retraction device for a multi-stage boom, such as a crane, in which the multi-stage boom can be extended and retracted in a predetermined order.

Generally, cranes and the like employ multi-stage booms, and it is preferable that these multi-stage booms operate one after another according to a fixed order. For this purpose, devices that hydraulically control sequential operation are used, but they have the disadvantage that sequential operation cannot be maintained if abnormally high pressure is generated due to frictional resistance, etc., and the overall cost is high. .

The present invention has been made in view of the above drawbacks.
To provide a multi-stage boom extension/retraction device that can reliably perform sequential extension/retraction operations of the multi-stage boom with an extremely simple configuration.

To explain the first embodiment of the present invention with reference to the drawings, as shown in FIG. It consists of a second boom (intermediate boom) 2 that extends and retracts, and a third boom (tip boom) 3 that slides within the second boom 2 and extends and contracts with respect to the second boom 2. The tip of the piston rod 5 of the hydraulic cylinder 4 is pivoted 5' at the end, and the tip of the cylinder barrel 6 of the hydraulic cylinder 4 is pivoted 6' to the inner base end of the second boom 2. 2. A cylinder barrel 8 base end of a hydraulic cylinder 7 is pivotally supported 8' at the inner base end of the boom 2.
The tip of the piston rod 9 is pivoted 9' to the inner tip of the third boom 3. Therefore, the expansion and contraction of the hydraulic cylinder 4 is caused by the expansion and contraction of the first boom 1 of the second boom 2.
The expansion and contraction of the hydraulic cylinder 7 is accompanied by the expansion and contraction of the third boom 3 with respect to the second boom 2.

By the way, the upper wall of the base of the second boom 2 has a first boom/second boom locking device 10 (hereinafter referred to as the first locking device) and a second boom/third boom locking device 11 (hereinafter referred to as the second locking device). ) are provided respectively.

First, the first locking device 10 will be explained.
A guide 12 is fixed to the base of the upper wall of the second boom 2 through the upper wall, and a shaft 13 is inserted into the guide 12 slightly beyond the upper and lower ends of the guide 12. A locking arm 15 having a locking portion 14 at its upper portion and an abutment arm 16 at its lower portion are fixed to this shaft 13, respectively. On the other hand, a stopper 17 is fixed to a suitable position on the outer surface of the upper wall of the second boom, and the locking arm 15 and the colliding arm are biased by a spring 18 stretched between the end of the locking arm 15 and the second boom 2. 16 is restricted from rotating clockwise relative to the guide 12. By the way, a locking roller 19 that can be locked to the locking portion 14 of the locking arm 15 described above is fixed to the tip of the inner surface of the upper wall of the first boom 1. An abutment roller 20 that can abut against the aforesaid abutment arm 16 is fixed to the base of the outer surface of the wall. Therefore,
When the multi-stage boom is in the contracted state, the abutting roller 20 abuts the abutting arm 16 and rotates the abutting arm 16 and the locking arm 15 counterclockwise against the spring 18.

Next, the second locking device 11 will be explained. A guide 21 is fixed to the base of the upper wall of the second boom 2 through the upper wall, and a shaft 2 is inserted into the guide 21.
2 is inserted slightly beyond the upper and lower ends of the guide 21. A locking arm 24 having a locking portion 23 at its lower portion and an abutting arm 25 at its upper portion are fixed to the shaft 22, respectively. On the other hand, a stopper 26 is fixed to a suitable position on the inner surface of the upper wall of the second boom 2, and a spring 27 is stretched between the end of the locking arm 24 and the second boom 2.
The clockwise rotation of the locking arm 24 and the abutting arm 25, which are biased by the guide 21, is restricted. By the way, on the outer surface of the upper wall of the third boom 3 and at its base, there is the above-mentioned locking arm 24.
A locking roller 28 that can be locked to the locking portion 23 of the first boom 1 is fixed to the locking roller 28, and a locking roller 28 that can be locked to the locking portion 23 of the first boom 1 is attached to the inner surface of the upper wall of the first boom 1, at the tip of which a locking roller 28 can be locked to the locking portion 23 of the first boom 1. A roller 29 is fixed. Therefore, when the multistage boom is in the contracted state, the locking roller 28 is locked to the locking portion 23 of the locking arm 24.

FIG. 3 shows the hydraulic system of the aforementioned hydraulic cylinders 4 and 7. Two oil passages 30 and 31 pass through the piston rod 5 of the hydraulic cylinder 4 in its length direction, and each oil passage 30 and 31 is connected to the main switching valve 32.
They are alternately connected to an oil tank 33 or a hydraulic pump 34 that pumps the hydraulic oil in the oil tank 33 via.

The oil passage 30 is connected to a pipe line 35 via a piston back pressure side oil chamber of the hydraulic cylinder 4, and the pipe line 35 is connected to a piston back pressure side oil chamber of the hydraulic cylinder 7.

The oil passage 31 is connected to the piston rod side oil chamber of the hydraulic cylinder 4, and the piston rod side oil chamber of the hydraulic cylinder 4 and the piston rod side oil chamber of the hydraulic cylinder 7 are connected by a pipe line 36.

Next, to explain the operation of the present invention, when the hydraulic pump 34 is operated and the main switching valve 32 is switched to the left position, the pressure oil flows through the oil passage 30 to the piston back pressure side oil chamber of the hydraulic cylinder 4 and to the pipe line. 35 to reach the piston back pressure side oil chamber of the hydraulic cylinder 7. At this time, the first locking device 10 releases the engagement between the first boom 1 and the second boom 2, while the second locking device 11 locks the second boom 2 and the third boom 3. .

That is, in the second locking device 11, the locking roller 28 is locked to the locking portion 23 of the locking arm 24, so that the third boom 3 cannot be extended further than the second boom 2. There is.

Therefore, by first extending the hydraulic cylinder 4, the second boom 2 will extend further than the first boom 1 while holding the third boom 3.

When the hydraulic cylinder 4 is fully extended, that is, the second
When the boom 2 is fully extended, the abutting roller 29 of the second locking device 11 fixed to the inner surface of the upper wall of the tip of the first boom 1 comes into abutting contact with the abutting arm 25, and the abutting arm 25 is moved by the spring 27. The locking portion 23 of the locking arm 24 is disengaged from the locking roller 28 in order to rotate the locking arm 24 counterclockwise.

Therefore, the binding between the second boom 2 and the third boom 3 is released, pressure oil is supplied through the pipe 35, the hydraulic cylinder 7 is extended, and the third boom 3 is moved from the second boom 2. It will expand. By the way, when the second boom 2 is extended to the maximum than the first boom 1, the locking arm 15 of the first locking device 10
It faces the locking roller 19 fixed to the tip of the boom 1, and as described above, when the third boom 3 starts to extend more than the second boom 2, the colliding roller 20
is detached from the abutment arm 16. Therefore, the locking arm 15 is urged by the spring 18 and rotates clockwise, and the locking portion 14 locks the locking roller 19. That is, the first boom 1 and the second boom 2 are tied together.

Also, when the multi-stage boom is retracted, if the main switching valve 32 is switched to the right position, the pressure oil will flow through the oil path 3.
1 to the piston rod side oil chamber of the hydraulic cylinder 4, and to the piston rod side oil chamber of the hydraulic cylinder 7 via the conduit 36. At this time, in the first locking device 10, the locking roller 19
5, and the first boom 1
and the second boom 2 are secured, and in the second locking device 11, the abutting roller 29 is connected to the locking arm 25.
Since the locking roller 28 is disengaged from the locking portion 23 of the locking arm 24 due to the rotation of the third boom 3 counterclockwise and further extension of the third boom 3, the hydraulic cylinder 7
Then, the third boom 3 starts to contract. When the third boom 3 is maximally contracted, the abutting roller 20 of the first locking device 10 abuts against and rotates the abutting arm 16, causing the locking roller 19 and the locking arm 1 to rotate.
5 from the locking part 14. Therefore, the binding between the second boom 2 and the first boom 1 is released, so the hydraulic cylinder 4 operates to contract, and the second boom 2 moves the first boom 1 while holding the third boom 3.
Shrink within. At this time, when the third boom 3 is contracted to the maximum, the locking roller 28 of the second locking device 11 is facing the locking part 23 of the locking arm 24, and when the second boom 2 is contracted, the abutting arm 25 is in collision. Matching roller 29
As a result, the locking arm 24 rotates clockwise due to the urging force of the spring 27, and the locking portion 23 of the locking arm 24 locks the locking roller 28, and the third boom 3 and the second Boom 2 will be secured.

In addition, even for multi-stage booms of four-stage booms or more, it is possible to sequentially operate any three consecutive booms among the multi-stage booms, and it can also be applied to the sequential operation of all multi-stage booms. However, other embodiments in combination with the device of the present invention will be described below.

FIG. 4 shows the first boom 1 shown in FIG.
In addition to the second boom 2 and the third boom 3, a fourth boom 37 is slidably inserted into the third boom 3. As for the first boom 1, the second boom 2, and the third boom 3, first and second locking devices 10 and 11 are provided as in the first embodiment.

Next, the expansion and contraction mechanism of the fourth boom 37 will be described.
A connecting member 38 of an appropriate length extends from the tip, and a pin hole 40 that matches the pin hole 39 drilled at the tip of the third boom 3 is provided at the tip of the connecting member 38.
and a pin hole 43 corresponding to the pin hole 42 drilled in the boom head 41 fixed to the tip of the fourth boom 37.
is provided, and when the pin 44 is inserted, the connecting member 38 and the third
The boom 3 or boom head 41 is fixedly connected to the boom 3 or the boom head 41. 45 is a lashing device for preventing simultaneous extension of the second boom 2 and third boom 3 when the fourth boom 37 is extended; The pin hole 49 drilled in the protruding piece 48 of No. 3 and the first
A protruding piece 50 of the boom 1 is aligned with a pin hole 51 formed therein, and a pin 44 is inserted through the pin hole 51 to secure the boom.
Note that the fourth boom 37 includes the fourth boom 3
When the fourth boom 37 is extended, a pin hole 52 is formed in the base of the fourth boom, which matches the pin hole 39 of the third boom 3 and into which the pin 44 is inserted. Pin hole 4 drilled in connecting member 38
0 and 43, pin holes 53 and 54 into which the pin 44 is inserted are bored in the fourth boom tip.
Reference numeral 55 is a fixing member fixed to the boom head 41, to which the above-mentioned connecting member 38 is engaged and detached.

Next, the extension and contraction operation of the second embodiment will be explained. First, when extending the multi-stage boom, as shown in FIG. and insert it into the pin hole 49 of the third boom 3, and
The second boom 2 and the third boom 3 are secured. Here, the pressure oil from the hydraulic pump 34 is pumped into the hydraulic cylinder 4.
When the hydraulic cylinder 4 is supplied to the piston backpressure side oil chamber at 7 and 7, the second boom 2 and the third boom 3 are secured by the pin 44 as described above, so the hydraulic cylinder 4 cannot be extended.

On the other hand, as for the hydraulic cylinder 7, its piston rod 9 is not secured in any way, so it extends.
In the end, only the fourth boom 37 is extended via the connecting member 38 and the fixing member 55.

When the fourth boom 37 is completely extended beyond the third boom 3, the switching valve 32 is switched and pressure oil is supplied to the piston rod side oil chamber of the hydraulic cylinder 7, and the fourth boom 37 is maintained in the extended state by the friction. Therefore, only the hydraulic cylinder 7 is reduced. When the hydraulic cylinder 7 is fully compressed, the pin 44 is inserted into the pin hole 4.
9, 47, and 51, and insert it into the pin hole 39 of the third boom 3, the pin hole 52 of the fourth boom 37, and the pin hole 40 of the connecting member 38, the first boom 1, the second boom 2, and the third boom At the same time as the lashing between the booms 3 is released, the fourth boom 37 is extended from the third boom 3, while the second boom 2 is inside the first boom 1, and the third boom 3 is inside the second boom. 2 and the hydraulic cylinder 7 is disposed between the second boom 2 and the third boom 3, so if the main switching valve 32 is switched to the left position again, As described in the first embodiment, the second boom 2 and the third boom 3 are extended in this order by the first locking device 10, and are in the working state.

On the other hand, when the work is completed and the store is to be stored, the main switching valve 32 is switched to the right position, and the second locking device 11
Accordingly, the third boom 3 and the second boom 2 are contracted in this order. In order to contract the fourth boom 37 into the third boom 3, the procedure described above may be reversed. That is, after pulling out the pins 44 from the pin holes 40, 52 and 39 and inserting them into the pin holes 49, 47 and 51, the main switching valve 32 is switched to the left position to extend the hydraulic cylinder 7 and the connecting member 38 is fixed. Material 55
bring it into contact with. Next, the pin 44 is pulled out from the plurality of pin holes described above and inserted into the pin hole 42 of the boom head 41, the pin hole 54 of the fourth boom 37, and the pin hole 43 of the connecting member 38, and then the main switching valve 32 is inserted.
When the fourth boom 37 is switched to the right position, the hydraulic cylinder 7 is contracted and the fourth boom 37 is contracted into the third boom 3. Thereafter, the pins 44 are transferred to the pin holes 49, 47, and 51 as shown in FIG. 4, and the vehicle is in a traveling and retracted state.

As described above, the present invention provides a locking arm having a locking portion and a collision arm coaxially disposed on an intermediate boom, and a collision roller on one of the booms at appropriate positions on the outer boom and the inner boom. In addition, locking rollers are arranged on the other boom, respectively, so that the multi-stage boom can be reliably extended and contracted in a fixed order.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and Fig. 1 is a cross-sectional side view showing the entire multi-stage boom, and Fig. 2 a and b.
3 is an enlarged plan view and a side view showing the first and second locking devices arranged on the intermediate boom, FIG. 3 is a hydraulic circuit diagram, and FIG. 4 is a cross-sectional side view of the multi-stage boom showing the second embodiment, FIG. 5 is an exploded sectional view showing the main parts of the second embodiment. 1...First boom, 2...Second boom, 3...
Third boom, 4,7...Hydraulic cylinder, 10,1
1...Locking device, 15, 24...Locking arm, 1
6, 25... Collision arm.

Claims (1)

[Scope of Claims] 1. A multi-stage boom in which one or more intermediate booms and tip booms are slidably inserted in sequence into a base end boom, and a hydraulic cylinder is disposed between the adjacent booms, A pair of locking devices are rotatably disposed at the base of the intermediate boom, and each of the locking devices includes a locking arm having a locking portion and an abutment arm integrated with the locking arm. the locking arm and the abutment arm of the other locking device are arranged on the outer surface of the intermediate boom, and the abutment arm of one locking device and the locking arm of the other locking device are respectively arranged on the inner surface of the intermediate boom; A locking roller and a collision arm that can be locked to the locking portion of the locking arm are provided on the inner surface of the tip of the boom adjacent to the outside corresponding to the locking arm and the collision arm located on the outer surface of the intermediate boom. A buttable abutment roller is secured, and a locking arm located on the inner surface of the intermediate boom and an abutment capable of abutting the abutment arm are attached to the outer surface of the base of the boom adjacent to the inner side corresponding to the abutment arm. A locking roller that can be locked is fixed to a locking portion of a mating roller and a locking arm, and the locking arm is configured to be biased in a direction to lock the locking roller, and the locking arm is configured to be biased in a direction to lock the locking roller. A multi-stage boom extension/retraction device characterized in that a boom that is not locked with a locking arm expands and contracts sequentially. 2. The multi-stage boom telescoping device according to claim 1, wherein the locking device is disposed on the upper wall or side wall of the intermediate boom.