JPS6353113B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sequential operating device for a multi-stage boom, such as a crane or an aerial work vehicle, in which the multi-stage boom can be extended and contracted in a predetermined order.

Cranes and aerial work vehicles generally employ multi-stage booms, and it is preferable that these multi-stage booms operate one after another according to a certain 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 sequential operation device for a multi-stage boom that can reliably extend and retract the multi-stage boom sequentially with an extremely simple configuration.

To explain an embodiment of the present invention with reference to the drawings, as shown in FIG. 2, and a third boom 3 that slides within the second boom and extends and contracts with respect to the second boom 2.
The piston rod tip of a hydraulic cylinder 4 is pivotally supported at the inner base end of the first boom 1, and the cylinder tip of the hydraulic cylinder 4 is pivotally supported at the inner base end of the second boom 2. The cylinder base end of a hydraulic cylinder 5 is pivotally supported at the inner base end of the second boom 2, and the piston rod tip of the hydraulic cylinder 5 is connected to the third boom 3.
It is pivoted on the inner tip of the. Therefore, expansion and contraction of the hydraulic cylinder 4 is accompanied by expansion and contraction of the second boom 2 with respect to the first boom 1, and expansion and contraction of the hydraulic cylinder 5 is accompanied by expansion and contraction of the third boom 3 with respect to the second boom 2.

On the other hand, guide grooves 6R and 6L are bored in the left and right side walls of the base of the second boom 2, and the periphery thereof is reinforced with a reinforcing plate 7. Lifting members 8R and 8L are provided. These elevating members 8R, 8L are the second boom 2
It is composed of a connecting member 9 that protrudes to the outside across guide grooves 6R and 6L bored in the side wall, and a guide member 10 and an abutting member 11 that are respectively fixed to the outer ends of the connecting member 9. The guide grooves 6R and 6L can be moved up and down. Note that the guide member 10 is preferably constructed of a ball bearing or the like.

By the way, a guide 12R is fixed to the inner surface of the right side wall at the tip of the first boom 1, and
An inclined surface is formed so as to be able to engage with the guide member 10 of the elevating member 8R when the elevating member 8R is extended. On the other hand, a stopper 13R is fixed to the outer surface of the right side wall at the base of the third boom 3, and comes into contact with the abutting member 11 of the elevating member 8R when the third boom 3 is retracted.

Further, a guide 12L is fixed to the outer surface of the left side wall at the base of the third boom 3, and has an inclined surface so that it can engage with the guide member 10 of the elevating member 8L along the inclined surface when the third boom 3 is contracted. is formed. A stopper 13L is fixed to the inner surface of the left side wall at the tip of the first boom 1, and comes into contact with the abutting member 11 of the elevating member 8L when the third boom 3 is extended.

FIG. 5 shows the hydraulic system of the aforementioned hydraulic cylinders 4 and 5. Two oil passages 14 and 15 pass through the piston rod of the hydraulic cylinder 4 in its length direction, and each oil passage 14 and 15 is connected to an oil tank 17 or inside the oil tank 17 via a main switching valve 16. The hydraulic pumps 18 are alternately connected to hydraulic pumps 18 that pump hydraulic fluid.

The oil passage 14 is connected to a pipe line 19 via a piston back pressure side oil chamber of the hydraulic cylinder 4, and the pipe line 19 is connected to a piston back pressure side oil chamber of the hydraulic cylinder 5.

The oil passage 15 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 5 are connected by a pipe line 20.

Next, to explain the operation of the present invention, when the hydraulic pump 18 is operated and the main switching valve 16 is switched to the left position, pressure oil is transferred to the piston back pressure side oil chamber of the hydraulic cylinder 4 and the hydraulic cylinder through the oil passage 14. 5
The oil is supplied to the back pressure side oil chamber of the piston, and both try to expand. At this time, the stopper 13R fixed to the outer surface of the side wall of the third boom 3
It is in contact with the abutment member 11 of R, and the second boom 2
Since the relative position between the third boom 3 and the third boom 3 does not change, the hydraulic cylinder 4 expands first. That is, the second boom will extend first more than the first boom 1.
When the hydraulic cylinder 4 is fully extended, the second
When the boom 2 is fully extended, the lifting member 8 is placed on the inclined surface of the guide 12R fixed to the inner surface of the side wall of the first boom 1.
Since the guide member 10 of R rides on and the elevating member 8 moves above the guide groove 6R, the contact relationship between the stopper 13R fixed to the third boom 3 and the abutting member 11 of the elevating member 8R is released. . As a result, the second
Since the fixation between the boom 2 and the third boom 3 is released, the hydraulic cylinder 5 is extended by the pressure oil that has flowed into the piston back pressure side oil chamber of the hydraulic cylinder 5 via the pipe 19. Therefore, the third boom 3 is extended more than the second boom 2.

At this time, the pressure oil in the piston rod side oil chamber of the hydraulic cylinder 4 is directly supplied to the oil passage 15, and the pressure oil in the piston rod side oil chamber of the hydraulic cylinder 5 is supplied to the pipe 20.
The oil returns to the tank 17 from the oil passage 15 via the piston rod side oil chamber of the hydraulic cylinder 4.

After the crane work is completed, to return to the stored state, operate the switching valve 17 to the right position to close the hydraulic cylinders 4,
Pressure oil from the hydraulic pump 18 may be supplied to the piston rod side oil chamber of No. 5. At this time, the first boom 1 and the second boom 2 are in contact with the stopper 13L fixed to the inner surface of the side wall of the first boom 1 and the abutment member 11 of the elevating member 8L, so the relative positions of both booms do not change. First, the reduction starts from the third boom 3.
When the third boom 3 reaches the most retracted position, the inclined surface of the guide 12L fixed to the outer surface of the side wall of the third boom 3 lifts the guide member 10 of the elevating member 8L upward, and the stopper 13L and the abutment member 11 come into contact with each other. The relationship is canceled. Therefore, the lashing relationship between the first boom 1 and the second boom 2 is released, and the hydraulic cylinder 4
is contracted, and therefore, the second boom 2 is contracted into the first boom 1 while holding the third boom in the contracted state.

As described above, the present invention includes guide members provided on the left and right sides of the second boom side wall, stoppers provided on the first boom and third boom corresponding to the guide members, and in contact with the guide members. With a simple configuration consisting of a guide that raises and lowers the guide member, it is possible to automatically move the stopper that does not come into contact with the guide member by simply switching the hydraulic switching valve of the hydraulic cylinder connected between each boom. It is something that can be reliably expanded or reduced sequentially.

[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 multistage boom, FIG. 2 is a partial cross-sectional view showing the positional relationship of the elevating member, guide, and stopper on one side, and FIG. The figure is a sectional view taken along the line in Figure 2 with the lifting member in the lowered position, Figure 4 is a perspective view of the lifting member, Figure 5 is a hydraulic circuit diagram, Figure 6a,
b and c are side views showing the multistage boom in an extended operating state, and FIG. 7 is a side view showing the multistage boom in a contracting operating state. DESCRIPTION OF SYMBOLS 1...First boom, 2...Second boom, 3...Third boom, 4, 5...Hydraulic cylinder, 6(R,L)...Guide groove, 8(R,L)...Elevating member, 12(R,L)... )
...Guide, 13 (R, L)...Stopper.

Claims (1)

[Claims] 1. A first boom, a second boom slidably inserted into the first boom, and a third boom slidably inserted into the second boom, In the multistage boom including hydraulic cylinders disposed between the respective booms, a guide member located on the outer surface of the side wall and a shock absorber located on the inner surface of the side wall are provided on one side of the guide groove formed on both side walls of the second boom base. An elevating member made of a mating member is disposed to be movable up and down, while an elevating member made of a mating member located on the outer surface of the side wall and a guide member located on the inner surface of the side wall is disposed on the other side of the guide groove so as to be movable up and down. Further, a guide that engages with a guide member of the one side elevating member and guides the elevating member in the vertical direction is provided on the inner surface of the one side wall of the first boom tip, and a guide is provided on the outer surface of the one side wall of the third boom base. A stopper that can come into contact with the abutting member of the one side lifting member is fixed to each of the stoppers, and a stopper that can come into contact with the abutting member of the other side lifting member is fixed to the inner surface of the other side wall of the first boom tip. A stopper is fixed to the outer surface of the other side wall of the third boom base to engage with a guide member of the other elevating member and guide the elevating member in the vertical direction. A sequential operating device for a multi-stage boom, characterized in that the stoppers that are not in contact with the mating members are sequentially extended and contracted from the fixed boom. 2. The multistage boom sequential actuation device according to claim 1, wherein the guide member of the elevating member is a roller or a bearing.