JPS63212693A - Semiautomatic expansion device for most head boom in simultaneous expansion multistage boom - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a semi-automatic extension and retraction device for the most advanced boom in a multi-stage boom of a truck-mounted crane.

(Prior Art) When pulling out and retracting the most advanced boom of a multi-stage boom, a method of manually extending and retracting the most advanced boom has been used in the simultaneous extension method. However, the more multi-stage it becomes, the more difficult it becomes to extend and retract it with two manual operations, and one method has been taken as a countermeasure.

There was an inconvenience when pulling in and out of the trunk due to the difference in effectiveness, such as not being able to work on the cargo bed of the trunk.

(Problem to be solved by the invention) In recent years, the booms of truck-mounted cranes have also been trending toward multi-tiered booms. , users are now being forced to make choices such as whether to manually pull out the tip boom or not. However, as it becomes difficult to pull out the tip boom manually, people are starting to think about whether there is a semi-automatic solution between the former and the latter.

(Means for solving the problem) Assuming that the fourth stage boom is the most advanced boom, the second and third stage booms are simultaneously telescopic booms (the second stage boom extends by the stroke of the cylinder). , the third stage boom extends twice the cylinder stroke), and the most advanced boom (fourth stage boom) can be set and stored semi-automatically via a cam mechanism etc.
I device.

(Structure of the Invention) As described above, the drawings of the embodiments of the present invention are illustrated with a four-stage boom, but it should be noted at the outset that a three-stage or a long boom may also be used.

About the drawings 1 is the first stage boom, 2 is the second stage boom, 3
is the third stage boom, 4 is the fourth stage boom, 5 is the telescopic cylinder, 6 is the storage (iil small) cam, 7 is the extension cam, 8 is the storage pin, 9 is the extension pin 1O is the cam switching lever , 10a is a round bar, 11 is a wire lobe for withdrawal, 12 is a wire lobe for retraction, 13 is a tension spring, 14 is a hole for cam switching, 15 is a stopper for a storage cam, 16 is a stopper for an extension cam,
18 is the shaft, 19 is the spring, 20 is the pin, 21,
22 and 23 are respective pin holes.

In FIG. 1, a first stage boom 1 and a second stage boom 2 are connected by a telescopic cylinder 5, and a first stage boom 1. The second-stage boom 2 and the third-stage boom 3 are connected via a pull-out wire robe 11 and a retraction wire robe 12, so that the second-stage boom 2. Third stage boom 3
forms a simultaneous telescopic multi-stage boom. Fourth stage boom 4
is connected to the third stage boom 3 by a pin 20 in the retracted state. This fourth stage boom has an extension bin 9 for extension and storage. A cam switching lever 10 is attached to the tip of the third boom 3 to which a storage pin 8 is attached, and an extension cam 7 and a storage cam 6 are attached to the tip of the telescopic cylinder 5 for extending and storing the fourth boom 4. are attached to each.

The round bar 10a is fixed to a lever lO, is able to slide up and down using a shaft 18 as a guide, and is biased downward by a spring. Hole 21 in the third stage boom 3. Since the boom 4 is provided with holes 22 and 23, the lever 10 can be attached even when the boom 4 is stored in the boom 3 or when it is extended.
When pushed in, the round bar 10 is inserted into the hole 14 of the cam 6 in Fig. 6.
A can be inserted and the cam can be rotated to extend and retract the boom 4.

(Operation of the invention) First, let us explain from the time when the fourth stage boom 4 (the most advanced boom) is extended. As shown in Fig. 2, the pin 20
Remove the boom 4 to make it free. A cam switching lever 10 attached to the third stage boom 3 switches the extension cam 7 and the storage cam 6 to the fourth stage boom extension state. (Figure 7) When the telescopic cylinder 5 is extended, the boom 2 will be extended by the stroke of the cylinder, and the boom 3 will be extended twice as much as the stroke of the cylinder. When the telescopic cylinder 5 is completely extended from the state shown in FIG. 8, the extension bin 9 installed on the fourth stage boom 4 becomes the state shown in FIG. 9.

Next, when the telescopic cylinder 5 is retracted, the boom 2 is retracted at the same speed as the telescopic cylinder 5, and the boom 3 is retracted at twice the speed. At this time, as shown in FIG. 9, the extension cam 7 attached to the tip of the cylinder and the extension bin 9 fixed to the boom 4 are in pressure contact with each other, so the boom 4 can only be retracted at the same speed as the telescopic cylinder 5. Therefore, the telescopic cylinder A contraction difference (shift) occurs between the boom 3 and the boom 3, which is contracting at twice the speed of the boom 5, resulting in the state shown in the fourth figure.

When the cylinder is completely retracted, the boom 4 will be extended more than the boom 3 by the stroke of the cylinder (this refers to the part of the fourth stage boom exposed from the third stage boom). (Illustrated) Next, insert the pin 20 and the center is completed.

To explain the case when the fourth-stage boom is stored, as shown in FIG. 5, the storage cam 6 is switched by the cam switching lever 10 with only the fourth-stage boom 4 extended. At this time, the extension cam 7 remains in contact with the extension bottle 9. (
10) When the telescopic cylinder 5 is extended, the second stage boom 2. The third stage boom 3 extends simultaneously. At this time, a storage cam 6 installed at the tip of the telescopic cylinder 5
Since the storage pin 8 installed in the fourth stage boom 4 is in contact with the fourth stage boom 4, the extension speed of the fourth stage boom 4 is the same as the extension speed of the telescopic cylinder 5 and the second stage boom 2. Therefore, the boom 4 is gradually retracted into the boom 3.

When the telescopic cylinder 5 is fully extended, the fourth stage boom is in a retracted state. (Fig. 3) When the telescopic cylinder is extended, when the retraction cam 6 and the retraction pin 8 come into contact, a gap is created between the extension cam 7 and the extension pin 9. Rotate counterclockwise until it hits the extension cam stopper 16.

Next, when the telescopic cylinder 5 is contracted, the second stage poom 2 and the third stage boom 3 are simultaneously contracted.

When the telescopic cylinder 5 completes its contraction, the boom is retracted as shown in the second figure. FIG. 12 shows the relationship between the extension cam 7, the storage cam 6, the extension pin 9, and the storage pin 8 immediately after the telescopic cylinder is contracted at this time.
Since the cam 7 and the extension pin 9 are in a position where they do not come into contact with each other, it becomes as shown in Fig. 2.

Insert the pin 20 and storage is completed.

As can be seen from the above results, by extending the second and third stage booms in the state shown in Fig. 5, that is, the state in which the most advanced boom 4 is extended, the longest boom length can be achieved in the state shown in Fig. 3. (with the fourth stage boom pulled out).

As explained above, the embodiment of the present invention is just one example, and 2. For example, a cam is used in the boom telescoping switching mechanism, but it is not limited to the cam mechanism. Also, although this mechanism is set inside the boom, it may also be installed outside (it is intended to include various possible mechanisms within the scope of the present invention).

(Effects of the invention) Based on the above configuration, as mentioned above, it is cheaper compared to creating a fully automatic type with a complicated structure, and compared to a manual type where the boom cannot be pulled out on the loading platform. The semi-automatic type according to the proposed method not only reduces labor, but also has the advantage of being able to be operated on the loading platform with a simple task of replacing pins.

[Brief explanation of the drawing]

The drawings are an example of the implementation of the present invention. Figure 1 is a sectional view of the entire boom retracted, and Figures 2 to 5 are the fourth stage boom 4.
6 is an explanatory diagram showing the operating state of each boom during extension and retraction (retraction). FIG. 6 is an explanatory diagram showing the cam 6 and pin 7 in FIG. FIG. 6 is an explanatory diagram showing the operations of the extension cam 7, the storage cam 6, the extension pin 9, and the storage pin 8 when the stage boom 4 is extended and retracted. 1...First stage boom 2...Second stage boom
3...Third stage boom 4...Fourth stage (the most advanced)
Boom 5...Telescopic cylinder 6.7...Cam 15.16...Cam stopper Patent applicant Maeda Manufacturing Co., Ltd. 1 Inkei '3I! i21 Insertion I4- Sensou 5 Figure Tato et al.
*-1 and 4 costs to Kaede

Claims (1)

[Claims] 1. In a multi-stage telescopic boom in which the front two stages of the most advanced boom are simultaneous telescopic booms, the most advanced boom is provided with a locking piece for telescoping, a boom telescopic switching mechanism is attached to a cylinder that interlocks the simultaneous telescopic boom, and A semi-automatic extension/retraction device for the most advanced boom in a simultaneous telescoping multi-stage boom, which is characterized by creating an expansion/contraction difference (shift) between the most advanced boom and the previous boom when the most advanced boom is extended/retracted.