JPS6216470Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a crane such as a truck crane that has a jib on its boom, and particularly to a jib device for extending and folding the jib.

Cranes such as truck cranes are generally equipped with a jib device. This jib device has shafts protruding from both sides of the tip of the boom of the crane, and is configured such that both fork recesses at the base end of the jib can be fitted into these shafts. By fitting the concave portions and rotating the jib around the axis, the jib can be extended toward the tip of the boom, or conversely folded along the underside of the boom.

Therefore, with the above-mentioned jib device, by extending the jib to the tip of the boom when in use, the boom length of the boom can be compensated for, and a large working range of the crane and a large lifting height of the load can be secured. On the other hand, when not in use, the above-mentioned jib can be folded under the boom and then stored under or to the side, so that there is no hindrance to crane work using only the boom.

By the way, when it comes to the jib of the jib device, it is desirable to make the length as long as possible in order to expand the working range and lifting height. However, if the jib is too long,
When folded, the tip of this jib comes into contact with the undulation cylinder that makes up and down the boom. For this reason, in the past, the length of the jib was limited to the range from the tip of the boom to the tip of the luffing cylinder.
There was a problem that it was not possible to secure a longer length.

For this reason, the inventor made it possible to tilt the jib to the side of the boom by loosely fitting one of the fork recesses with respect to its axis, thereby making it possible to tilt the jib to the side of the boom. I thought about folding the jib in this tilted state. Therefore, in such a folded posture of the jib, the tip side of the jib does not come into contact with the undulating cylinder, and a sufficient length of the jib can be ensured.

However, in the above configuration, one of the fork recesses is loosely fitted to its shaft, so when the jib is suspended from both shafts, the jib is tilted due to its own weight. Therefore, the jib is rotated around the axis while remaining in this position and folded onto the lower surface of the boom. For this reason, when the jib is to be rotated, the hook suspended from the tip of the boom via a wire becomes an obstacle, making it difficult to rotate the jib easily.

This idea was made based on these circumstances, and its purpose is to provide a crane jib device that allows the jib to rotate without the boom hook getting in the way. .

In other words, this invention allows the jib to be tilted to the side of the boom by loosely fitting one of the fork recesses with respect to its shaft, and when the jib is suspended from the shaft, the jib can be tilted to the side of the other fork recess. It is characterized in that a weight for holding the jib vertically is detachably attached to the tip of the side surface of the jib.

An embodiment of this invention will be described below based on the drawings.

Figure 1 shows a truck crane, 1 is the car body,
2 is a swivel base, 3 is an extendable boom, 4 is a hook for this boom 3, 5 is a undulating cylinder for the boom 3, 6 is a driving cab for traveling, and 7 is a cab for crane work.

A jib 8 is stored in the lower surface of the boom 3, and the jib 8 is detachably supported by supports 9 and 10 attached to the lower surface of the boom 3. In addition, 12 is an auxiliary wire 13 for the jib 3.
The stopper 14 is also a guide for the auxiliary wire 13.

Therefore, shafts 15a and 15b are provided protruding from both sides of the tip 3a of the boom 3,
These shafts 15a, 15b are used for extending and folding the jib 8. That is, the proximal end 16 of the jib 8 is connected to the distal end 3 of the boom 3.
The jib 8 is configured so that the jib 8 can be loosely fitted.
Fork recesses 17a and 17b are formed at both base ends of the fork recesses 17a and 17b, respectively. These fork recesses 17a,
17b is removably fitted to the shafts 15a, 15b, respectively, and therefore the fork recesses 17a, 1 are fitted to these shafts 15a, 15b.
The jib 8 is extended and folded by rotating the jib 8 around the shafts 15a and 15b in a state in which the jib 7b is fitted. Note that 21 is a single rope boom at the tip of the boom 3.

Further, in both fork recesses 17a and 17b, for example, retaining pins 19 and 19 are provided as retaining devices.
is now available for installation. These retaining pins 1
9 and 19 are removably inserted into pin holes 20 and 20 formed in the fork recesses 17a and 17b, thereby preventing the shafts 15a and 15b from coming off when the jib 8 is rotated.

In this embodiment, one of the fork recesses 1
7a is configured to be loosely fit onto the shaft 15a. That is, in the fork recess 17a, as shown in FIG.
The distance l ₁ from the bottom of the fork to the pin hole 20 is set larger than the distance l ₂ at the other fork recess 17b, thereby making it possible to tilt the jib 8 to the side of the boom 3. . Note that a notch A is formed in the bottom surface of the other fork recess 17b to facilitate tilting of the jib 8.

Further, as shown in FIG. 4, a weight 22 can be attached to the tip side of the side surface of the jib 8 on the side of the other fork recess 17b. This weight 22 has a threaded portion 23
When the weight 22 is attached and the jib 8 is suspended from the shafts 15a and 15b, the weight of the weight 22 holds the jib 8 vertically. It is set to the possible weight.

Next, the operation of one embodiment with the above configuration will be explained. First, when extending and folding the jib 8, both fork recesses 17a and 17 of the jib 8 are
b is fitted onto each shaft 15a, 15b, and retaining pins 19, 19 are inserted into pin holes 20, 20, respectively, to prevent these shafts 15a, 15b from coming off. As a result, one of the fork recesses 1
7a, the shaft 15a is loosely fitted, and the jib 8 is suspended from the side of the boom 3 so as to be tiltable. Therefore, in this state, the shafts 15a,
When the jib 8 is rotated around 15b and folded, the jib 8 can be tilted with its own weight against the boom 3, and as shown in FIG. Can be folded.
Therefore, as is clear from FIG. 2, even if the jib 8 is long, the tip side of the jib 8 is connected to the luffing cylinder 5
It does not come into contact with the cylinder 5, and can be folded while avoiding the undulation cylinder 5. As a result, a sufficient length of the jib 8 can be ensured, and the working performance of the crane can be greatly improved.

Further, in this embodiment, the other fork recess 17
Since the weight 22 can be attached to the tip side of the side surface of the jib 8 on the b side, when the jib 8 is suspended from the shafts 15a and 15b as shown in FIG. By attaching the jib 8, the jib 8 can be held vertically as shown in FIG. 6 even if one of the fork recesses 17a is loosely fitted. Therefore, if the jib 8 is rotated in this position, the hook 4 of the boom 3 can be automatically passed through the center opening on the base end side of the jib 8, and the jib 8 can be rotated. The hook 4 does not get in the way when rotating the handle 8. Therefore, when rotating the jib 8, there is no need for a separate worker to pass the hook 4, and the jib 8 can be easily rotated by one worker. Note that, as shown in FIG. 5, the rotation of the jib 8 is controlled by the auxiliary wire 1.
3, and the above-mentioned hook 4
By removing the weight 22 after passing the
This jib 8 can be tilted diagonally by its own weight.

Although the above embodiment shows an example in which the invention is applied to a truck crane, it goes without saying that this invention can be applied not only to this truck crane but also to a vehicle-type crane having a dual-purpose operator's cab for both crane work and traveling. This can also be applied to various cranes equipped with jibs, such as tower cranes.

As explained above, this invention allows the jib to be tilted to the side of the boom by loosely fitting the recessed part of one fork with respect to its axis, and when the jib is suspended from the boom axis, the other fork The present invention is characterized in that a weight for holding the jib vertically is detachably attached to the tip of the side surface of the jib on the side of the recess. Therefore, since one of the fork recesses is loosely fitted to its shaft, the jib can be tilted diagonally when folded. Therefore, a sufficient length of the jib can be ensured without the tip side of the jib interfering with the luffing cylinder, and the performance of the crane can be improved. Further, when the jib is suspended from the shaft, the jib can be held vertically by attaching a weight to the jib. Therefore, when rotating the jib, the hook at the tip of the boom can be passed through the center of the jib, so that the jib can be rotated without the hook getting in the way.

[Brief explanation of the drawing]

The drawings show one embodiment of this invention, in which Fig. 1 is a side view of the truck crane, Fig. 2 is a bottom view of the boom, Fig. 3 is a bottom view showing a partial cross section of the base end of the jib, and Fig. FIG. 4 is a bottom view partially sectionally showing the tip of the jib, FIG. 5 is a side view of the boom, and FIG. 6 is a view taken from the direction of the arrow in FIG. 3...Boom, 4...Hook, 5...Luffing cylinder, 15a, 15b...Axle, 17a, 17b...
...Fork recess, 22... weight.

Claims (1)

[Scope of utility model registration request] A boom is provided which is raised and lowered by a hoisting cylinder, and shafts are provided respectively protruding from both sides of the tip of this boom, and both fork recesses at the base end of the jib are fitted to these shafts to rotate the jib around the above-mentioned shafts. In a crane jib device, the jib is extended toward the tip of the boom and folded along the bottom surface of the boom by the movement of the fork. The jib is configured to be tiltable to the side of the boom, and when the jib is suspended from the shaft, a weight that holds the jib vertically is detachably attached to the tip of the side of the jib on the side of the other fork recess. A crane jib device that is characterized by the following: