JPH0518372Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial field of application) This invention is a device for tensioning a jib on a boom, and in particular, a jib tensioning device for a boom that is capable of adjusting the tension angle for a telescopic boom such as a truck crane. This relates to a tensioning device.

(Prior art) A telescoping boom in which a jib is attached to the boom head of a telescoping boom such as a conventional truck crane, and the jib is provided to adjust the tension angle (tilt angle) with respect to the telescoping boom. The jib tensioning device is such that both sides of the lower part of the jib are pivoted to the lower part of the boom head of a telescoping boom, and the ends of the jib and the upper part of the boom head are connected by a telescoping cylinder and a tension member.
The extension angle of the jib relative to the telescopic boom can be adjusted by extending and retracting the telescopic cylinder, and the lower part of the base of the jib is pivoted to the lower part of the boom head of the telescopic boom, and the upper part of the base of the jib and the upper part of the boom head are attached to the lower part of the boom head of the telescopic boom. It is known that a hydraulic cylinder is provided between the boom and the boom, and the tension angle of the jib relative to the telescopic boom can be adjusted by expanding and contracting the hydraulic cylinder.

In addition, an auxiliary jib is rotatably attached to the top of the telescopic boom, and the auxiliary jib is attached to a hydraulic cylinder as an actuator, one end of which is pivoted to a horizontal shaft on the auxiliary jib, and the end of the piston rod of the hydraulic cylinder. The connected tilt angle adjustment rope is stretched over the boom head of the telescopic boom via a guide sheave provided at a suitable position on the auxiliary jib, and pressure oil is supplied and discharged from the hydraulic cylinder to extend and retract the auxiliary jib. Some models have already been proposed in which the tilt angle relative to the boom can be adjusted (for example,
(Refer to Utility Model Publication No. 100390/1983).

(Problem to be solved by the invention) However, in the conventional jib tensioning device for a telescopic boom as described above, the tensioning angle of the jib with respect to the longitudinal direction of the telescopic boom is controlled by the expansion and contraction of a hydraulic cylinder. Although it can be adjusted, the axial direction of the mounting pin of the hydraulic cylinder provided directly or via a tension member between the end of the jib whose lower side of the base is pivoted to the boom head or the upper side of the base of the jib is Because it was installed horizontally in the same direction as the mounting axis of the jib base, for example, the hook at the lower end of the sub-rope hanging from the sheave at the tip of the jib could be used to prevent the telescopic boom from moving slightly to the left or right from the vertical plane containing the longitudinal center line. When carrying out cargo handling work by suspending a misaligned load or other object using the hook at the end of the sub-rope, the weight of the object is applied to the end of the jib in the vertical direction, as well as in the length direction of the telescopic boom. From the vertical plane passing through the center line of
A component force similar to W2) is simultaneously applied to the end of the jib, and this thrust forces the jib against the telescopic boom.

For this reason, the prying force acts on the hydraulic cylinder that supports the jib (specifically, its outer jib) against the telescopic boom, and the piston rod end of the hydraulic cylinder that supports the outer jib is forced to move against the cylinder body of the hydraulic cylinder that supports the outer jib. The piston may be twisted, causing wear and tear on the piston and cylinder body, and in extreme cases, a gap may be created between the piston periphery and the inner circumferential surface of the cylinder body.
There was a problem in that the pressure oil on the pressurizing side could leak to the opposite side.

Further, in the variable tilt device for the auxiliary jib in the telescopic boom with an auxiliary jib described in the above-mentioned Japanese Utility Model Publication No. 100390/1983, the auxiliary jib is swingably provided on the boom head of the telescoping boom, and
The tilt angle of the auxiliary jib with respect to the telescopic boom can be adjusted by expanding and contracting a hydraulic cylinder, and the center line of the piston rod of the hydraulic cylinder is aligned with a tangent to the first guide sheave on which the tilt angle adjustment rope is stretched. By selecting the setting position of the first guide sheep at an appropriate location on the auxiliary jib so that the first guide sheep matches the auxiliary jib, if a horizontal force is generated between the boom and the auxiliary jib, the force in the horizontal direction is The component force is absorbed by the tilt angle adjustment rope between the boom head and the first guide sheave, and no prying force is generated on the hydraulic cylinder, at least the hydraulic cylinder or its piston rod described in this publication. Since there is no consideration given to a structure that absorbs the prying force generated between the two and the tilt angle adjustment rope, it is assumed that the direction of the first guide sheave and the piston rod of the hydraulic cylinder is If the jib is misaligned for some reason, or if a hydraulic cylinder like the one described above is installed between the boom head and the top of the jib to connect them, the prying force generated between the hydraulic cylinder and the pair of tension members can be reduced. , which acts directly on the hydraulic cylinder section and impairs its oil-tightness, which poses a problem in that its applicability is limited.

In view of such conventional examples, this invention has the foot parts on both sides of the base of the jib supported by support shafts on both sides of the lower part of the boom head, and the top of a hydraulic cylinder is connected to the top of the jib. The tops of a pair of tension members whose bases are pivoted to both sides of the upper part of the boom head are connected to the lower part, and at least one of the two connection parts at the top and bottom of the hydraulic cylinder is movable in the horizontal direction. By connecting via a vertical axis, if an external force including a horizontal component force is applied to the end of the jib, the connection part will be swung horizontally about the vertical axis, and the It is an object of this invention to provide a device for tensioning a jib on a boom by absorbing horizontal component forces and thereby avoiding the above-mentioned problems.

(Means for Solving the Problems) In order to solve the problems in the conventional example as described above, this invention has been developed by attaching the top of the hydraulic cylinder to the top of the jib, in which the foot parts on both sides of the base are supported on the bottoms of both sides of the boom head. Connect the lower part of the hydraulic cylinder,
The base is connected to the tops of a pair of tension members pivoted on both sides of the upper part of the boom head, and at least one of the connections between the top and bottom of the hydraulic cylinder and the top of the jib and the top of the tension members is horizontal. They are connected via a vertical shaft that can swing in any direction.

(Function) Since this device has the above-mentioned configuration,
The tension angle of the jib relative to the telescopic boom can be adjusted by expanding and contracting the hydraulic cylinder, but if an external force including some lateral force is applied to the top of the jib, the top of the jib and the top of the hydraulic cylinder may and the connection between the lower part of the hydraulic cylinder and the top of a pair of tension members whose bases are pivoted on both sides of the upper part of the boom head, at least one of which is connected in a horizontal direction around the vertical axis of the connection. By swinging, the horizontal component of the external force is absorbed, and no unreasonable lateral force is applied to the hydraulic cylinder, thereby allowing the jib to perform smooth cargo handling operations.

(Embodiment) Hereinafter, an embodiment of a jib tensioning device for a boom according to this invention will be described with reference to the drawings.

In the figure, reference numeral 1 denotes a telescopic boom whose base is rotatably pivoted to a swivel platform of a crane vehicle (not shown), etc.;
2 and 3 are the base boom and end boom of the telescopic boom 1, 4 is the boom head at the end of the end boom 3, and 5
is a support shaft provided on both sides of the lower part of the boom head 4, and the support shaft 5 also serves as a support shaft for the sheave 7 for the main rope. 6 is a pin on both sides of the upper part of the boom head; 10 is a telescoping jib stretched over the boom head 4 of the telescoping boom 1; the telescoping jib 10 has a fork-like leg portion 12 as a foot portion below the base of the outer jib 11; It is supported by support shafts 5 on both sides of the boom head 4 of the telescopic boom 1, and its supported state is ensured by pins 13.

Note that the fork-shaped leg portion 12 at the base of the outer jib 11 may be configured as a foot portion with a hole structure (not shown) into which the support shaft 5 is directly inserted, instead of being divided into fork shapes as in the illustrated example. You can also do it.

14 is a protrusion that stands up from both the left and right (FIG. 4) sides of the top (left side in FIG. 2) of the outer jib 11; 15 is a mounting bolt for the concave seat 16 arranged between the protrusions 14;
17 is a bracket fixed to both ends of the outer jib 11, 18 is a horizontal support shaft for the bracket 19 to the upper part of the bracket 17, and 20 is a protrusion that projects from the center of the bracket 19 to the front of the outer jib 11 (left side in FIG. 2). A sheave 21 is supported by a shaft 22 on the projecting piece 20.

23 is a pin inserted into the hole at the end of the shaft 22; 24 is a guide for the sub-rope 45; 25 is a vertical shaft; the vertical shaft 25 is connected to the cylinder body 27 of the hydraulic cylinder 26;
28 is a piston rod, the vertical shaft 29 is a vertical shaft in the same direction as the vertical shaft 25, and the vertical shaft 29 is connected to a bracket 30 so as to be swingable in the horizontal direction. .

30 is a crank, 31, 31 are tension rods as tension members, 32 is an end piece, 33 is a pin, 34 is an end piece, and 35 is an elongated hole that engages with the pin 6. 40 is an inner jib, 41 is a jib head, 42 is a sheave, 43 is a shaft, and 46 is a hook.

(Function of the Embodiment) First, the hawk-like leg 12 on the lower side of the base (lower right side in Figure 1) of the outer jib 11 of the jib 10 is connected to the support shafts 5, 5 on both sides of the lower part of the boom head 4 of the telescopic boom 1. The supporting state is ensured by the pin 13.

Next, one end of the cylinder main body 27 of the hydraulic cylinder 26 is pivoted by the vertical shaft 25 to the bracket 19 which is pivoted to the upper part of the bracket 17 at the top of the outer jib 11 by the horizontal shaft 18, while the A bracket 30 is pivotally attached to the piston rod 28 so as to be able to swing in the horizontal direction by a vertical shaft 29, and a pair of tension rods 31, 31 are provided between both sides of the bracket 30 and the boom head.
The tops of the tension rods 31, 32 are connected to the tops of the tension rods 31,
Long holes 35, 35 in the end pieces 34, 34 of the base of 31
After inserting and assembling the pins 6, 6 on the boom head 4, the cylinder body 27 of the hydraulic cylinder 26 is assembled.
Pressure oil is introduced into either side of the piston rod 28 to extend and retract the piston rod 28 with respect to the cylinder body 27, and the tension angle of the jib 10 with respect to the telescopic boom 1 is adjusted appropriately.

Thereafter, the sub-rope 45 is wound in or unwound by a sub-winch (not shown), thereby carrying out the cargo handling operation using the jib 10.

According to this embodiment, as shown in FIG.
The telescopic boom 1 is attached by a hook 46 at the lower end of the sub rope 45 hanging from the sheave 42 at the tip of the jib 10.
The sub rope 45
When carrying out cargo handling work using the hook 46 at the end, the load of the object W is applied vertically to the end of the jib 10, as in the case of a normal jib 10.
Component force in the left-right (lateral) direction (W2) corresponding to the amount of displacement from the vertical plane passing through the longitudinal center line of
A thrust equivalent to 1 is simultaneously applied via the sub-rope 45, and this component force W2 forces the jib 10 against the telescopic boom 1, and the hydraulic cylinder 26 that supports the outer jib 11 against the telescopic boom 1 is also subjected to this prying force. Power tries to work.

However, in this case, the bracket 30, which connects the top of the tension rod 31, is arranged between the boom head 4 and the top of the outer jib 11.
and the piston rod 28 of the hydraulic cylinder 26 are connected via the brackets 19, 30, and their connecting portions are pivoted by vertical shafts 25, 29 so as to be swingable in the horizontal direction.
The prying force in the left and right (horizontal) direction that is about to be applied to the hydraulic cylinder 26 is absorbed by the horizontal rocking of this connection part around the vertical axes 25 and 29, and the force between the cylinder body 27 and the piston rod 28 is reduced. Not communicated.

Note that the brackets 19 and 30, the cylinder body 27 of the hydraulic cylinder 26, and the piston rod 2
Regarding the connection structure using horizontally swingable vertical shafts 25 and 29 that connect the ends of 8, by allowing the horizontal swings at the vertical shafts 25 and 29, it is possible to The vertical shaft 25,
Even if only one of the parts 29 is used, the prying force generated in the same part can be absorbed, and therefore,
Either one of the connection structures using the vertical shafts 25 and 29 does not swing in the horizontal direction other than the vertical axis, instead of the connection structure that can swing in the horizontal direction using the vertical shafts as in the illustrated example. It can also be configured as a connected structure (not shown).

The fork-shaped base 12 of the outer jib 11 of the jib 10 is supported by the support shaft 5 of the boom head 4, and the top side (the left side in FIG. 1) is always lowered due to its own weight, and the tension rod 31 is always Since a tension acts, this tension rod 31 can also be constructed instead of a wire rope (not shown).

However, when the tension member is constituted by a wire rope in this way, for example, the effect of suppressing the tilting that occurs in the jib 10 due to the swirl of the auxiliary wire rope 45 (the tension rod 31
However, we cannot expect the same effect even though we have set up a system.

Next, embodiments of this invention will be summarized and described.

(a) a bracket 19 that is pivotally attached to the top of the jib 10 so as to be able to swing vertically via a horizontal shaft 18;
A jib tensioning device for a boom in which the top of the hydraulic cylinder 27 is pivoted by a vertical shaft 25 that can swing in the horizontal direction.

(b) A pair of tension members whose bases are attached to shafts 6, 6 on both sides of the upper part of the boom head 4 on both sides of a bracket 30 which is attached to the lower part of the hydraulic cylinder 27 by a vertical shaft 29 that can swing horizontally. A jib tensioning device for a boom with pins 33, 33 attached to the tops of 31, 31.

(c) A bracket 19 is pivotally attached to the top of the jib 10 so as to be swingable in the vertical direction by a horizontal shaft, and the top of the hydraulic cylinder 27 is pivotably attached to the top of the jib 10 by a vertical shaft 25 that is pivotable in the horizontal direction. , a pair of tension members 3 whose bases are attached to shafts 6, 6 on both sides of the upper part of the boom head 4 are attached to both sides of a bracket 30 which is pivoted to the lower part of the hydraulic cylinder 27 by a vertical shaft 29 that can swing horizontally.
A jib tensioning device for a boom with pins 33 and 33 attached to the tops of 1 and 31.

(d) The tension member is a tension rod 3
A jib tensioning device for the boom consisting of 1 and 31.

(Effects of the invention) Since this invention has the above-mentioned configuration and functions, the following effects can be obtained.

(1) A pair of tension members in which the top of a hydraulic cylinder is connected to the top of a jib whose foot parts on both sides of the base are pivoted on both sides of the boom head, and the lower part of the hydraulic cylinder is pivoted to the base on both sides of the top of the boom head. and at least one of the connection parts between the top and bottom of the hydraulic cylinder and the top of the jib and the top of the tension member is connected via a vertical shaft that is horizontally swingable; If an external force including a lateral component of force acts on the jib, at least one of the connecting parts will swing horizontally around its vertical axis, thereby absorbing the horizontal component of the external force. Therefore, there is no risk of generating prying forces between the hydraulic cylinder, in particular its piston rod and the cylinder body.

(2) At least one of the top and bottom connections of the hydraulic cylinder is connected via a horizontally swingable vertical shaft, and no prying force is generated between the piston rod and the cylinder body;
There is no risk of pressure oil leaking from the hydraulic cylinder, and furthermore, there is no risk of the tension angle of the jib relative to the telescopic boom changing inadvertently.

(3) If the bracket, which is attached to the top of the jib so that it can swing up and down with a horizontal shaft, is connected to the top of the hydraulic cylinder through the vertical shaft that can swing horizontally, the bracket can be attached to the top of the jib. The stored hydraulic cylinder can be moved to its operating position by simply swinging the hydraulic cylinder upward by a slight angle from its stored position. As such, there is no need for extensive rotation such as moving it from the vertical direction along the boom head (Fig. 1) to the position where it connects with the tension rod.
Its mounting structure and operability are improved.

(4) If the tops of the pair of tension members are connected to both sides of the bracket, and the bracket and the lower part of the hydraulic cylinder are connected via a vertical shaft that can swing in the horizontal direction, the pair of tension members To provide a jib tensioning device for a boom, which allows the top of a tension member and the bottom of a hydraulic cylinder to swing in the horizontal direction, and has a simple connection structure without impairing its assemblability.

(5) If the top of the hydraulic cylinder is connected to the top of the hydraulic cylinder by a vertical shaft that can swing in the horizontal direction, the bracket, which is attached to the top of the jib so that it can swing vertically by a horizontal shaft, can be connected to the top of the hydraulic cylinder and the top of the hydraulic cylinder. A connection structure that can swing vertically and horizontally to the top of the jib is constructed around the bracket, and the upper end of the hydraulic cylinder can be easily attached to the top of the jib.

(6) A bracket mounted on the top of the jib so as to be able to swing in the vertical direction by a horizontal shaft, a connection portion between the top of the hydraulic cylinder, a lower part of the hydraulic cylinder, and the top of the pair of tension members. If both the brackets and the connection parts connected on both sides are connected by vertical shafts that can swing horizontally, even if a lateral external force is applied to the jib, both the upper and lower ends of the hydraulic cylinder This is effectively absorbed by both horizontally swingable vertical shafts disposed at the connection of the hydraulic cylinder, and the generation of prying forces between the hydraulic cylinder and its piston rod is more effectively prevented.

(7) If a hydraulic cylinder is fastened near the top of the jib and the bases of tension rods are provided on both sides of the upper part of the boom head, the spiral of the auxiliary wire rope for cargo handling can be controlled by cooperation with the tension rod connected to the hydraulic cylinder. The occurrence of tilting of the jib due to the above-mentioned hydraulic cylinder stops swinging due to contact with the upper side of the jib (see the same figure) after a slight swing, and there is an interposition between the end of this hydraulic cylinder and the boom head. It is quickly and effectively stopped by the tension rod.

(8) If the tension member is constituted by a tension rod, during cargo handling using this jib, if the cargo hits the lower end of the jib (the left side in Figure 1) due to the swirl of the auxiliary cargo handling wire rope, etc. The tension rod and the hydraulic cylinder prevent the jib from rotating excessively in the clockwise direction (Fig. 1) about the spindle on the boom head. Based on this, accidents can be prevented from occurring.

[Brief explanation of the drawing]

The drawings show an embodiment of a jib tensioning device for a boom according to this invention. Fig. 1 is a partially cutaway side view of the jib section, and Fig. 2 is a plan view of the main part thereof. , FIGS. 3 and 4 are sectional views taken along lines - and - in FIG. 1, and FIG. 5 is an explanatory view of its operation, showing its essential parts in a bottom view. 4...Boom head, 5...Spindle, 6,33...
...Pin, 10...Jib, 12...Leg, 17,1
9, 30... Bracket, 18... Horizontal support shaft, 2
2...Axis, 26...Hydraulic cylinder, 25, 29...
...Vertical axis, 31...Tension rod.

Claims (1)

[Claims for Utility Model Registration] (1) The top of a hydraulic cylinder is connected to the top of a jib whose foot parts on both sides of the base are supported on both sides of the bottom of the boom head, and the bottom of the hydraulic cylinder is connected to the top of the jib, and the base is connected to the top of the jib on both sides of the top of the boom head. and at least one of the connection parts between the top and bottom of the hydraulic cylinder and the top of the jib and the top of the tension member is vertically movable in the horizontal direction. A tensioning device for a jib on a boom, characterized in that it is connected via an axle. (2) A bracket mounted on the top of the jib so as to be swingable in the vertical direction via a horizontal shaft and the top of the hydraulic cylinder are connected via a vertical shaft that is swingable in the horizontal direction. A jib tensioning device for a boom according to claim 1 of the utility model registration claim. (3) The tops of a pair of tension members whose bases are pivoted on both sides of the upper part of the boom head are connected to both sides of the bracket, and the bracket and the lower part of the hydraulic cylinder are connected to each other by a vertical member that can swing in the horizontal direction. A jib tensioning device for a boom according to claim 1, characterized in that the device is connected via a shaft. (4) A bracket mounted on the top of the jib so as to be able to swing in the vertical direction by a horizontal shaft, a connection portion between the top of the hydraulic cylinder, a lower part of the hydraulic cylinder, and the top of the pair of tension members. The tensioning of a jib to a boom according to claim 1 of the utility model registration claim, characterized in that the connection parts with the brackets connected on both sides are connected via vertical shafts that can swing in the horizontal direction. Elevating equipment.