JP6604818B2 - Jib hoisting device for work equipment - Google Patents

Description

  The present invention relates to an improvement in a jib hoisting device for a work machine in which the jib is swung out to the tip of a boom by extending the entire length of the jib by an extension operation of the jib hoisting cylinder.

As this type of jib hoisting device, for example, the jib hoisting telescopic device disclosed in Patent Document 1 is already known.
As shown schematically in FIG. 9, the jib undulating and expanding device 100 disclosed in Patent Document 1 includes a plurality of jib components 104 and 105 attached to a base jib 103 pivotally attached to the tip of a boom 102 of a work machine 101. A telescopic jib body 106 having a telescopic structure fitted in order is used for raising and lowering, and a fixed-length cord (tension rod) 107 pulled out from the tip of the boom 102 is adjacent to the base jib 103. The jib body 106 is swung out by utilizing the tension of the rigging 107 by extending the entire length of the jib body 106 by the operation of the jib hoisting cylinder in a state where the movement of the jib component 104 is constrained on the 104. In the jib body 106, a jib component 104 adjacent to the base jib 103 is removed from the base jib 103. The jib hoisting cylinder for swinging out the jib body 106 while extending the entire length of the jib body 106 and the jib component 105 closer to the tip than the jib component 104 adjacent to the base jib 103 are advanced and retracted to extend the jib body 106. It has a built-in jib telescopic cylinder for expanding and contracting the entire length.
Specifically, the swing-out operation of the jib body 106 in this kind of jib hoisting device is performed as follows.
First, the base jib 103 is pivotally attached to the tip of the boom 102, and the rope 107 pulled out from the top surface of the boom 102 is fixed to the jib component 104 adjacent to the base jib 103 to restrain the movement of the jib component 104. In this state, when the jib hoisting cylinder in the jib body 106 is operated, the jib component 104 adjacent to the base jib 103 extends so as to protrude from the base jib 103, and the jib component 104 with the rigging 107 fixed thereto A jib body 106 extends between the base jib 103 and the base jib 103.
At this time, the pulling position (the position T1 in FIG. 9) of the rigging 107 on the upper end surface of the boom 102 is located above the pivot position (the position T2 in FIG. 9) of the base jib 103 at the distal end of the boom 102 In addition, the distance between the fastening position of the rigging element 107 (position T3 in FIG. 9) in the jib component 104 and the rigging pull-out position (position T1 in FIG. 9) on the top surface of the boom 102 is Since the jib main body 106 extends between the jib component 104 to which the cord 107 is fixed and the base jib 103, the jib main body 106 pivotally attached to the tip of the boom 102 is 9 oscillates in the vertical plane around the pivot position (position T2 in FIG. 9) of the base jib 103 at the tip of the boom 102 by the tension of the rigging 107, and the two-dot chain line in FIG. It is swung to the position of the jib body 106 'shown.
In the jib undulating and extending device 100 disclosed in Patent Document 1, the jib undulating cylinder and the jib extending and retracting cylinder are arranged in a straight line in the jib main body 106 along the longitudinal direction of the jib main body 106. Although the size of the jib body 106 is inevitably reduced, the jib body 106 is inevitable to increase in weight, and the jib undulation cylinder and the jib telescopic cylinder are arranged in a straight line. There is a concern that heavy weight distribution may adversely affect the strength of the jib body 106 and the boom 102 when the jib body 106 is extended, and the lifting performance (strength range performance) of the jib body 106.
Further, in the jib undulating and expanding device 100 disclosed in Patent Document 1, the internal structure of the jib main body 106 is constituted by two cylinders (jib undulating cylinder and jib expanding and contracting cylinder) arranged in a straight line in the jib main body 106. In addition, as the two cylinders are installed, the size of the space that can be used for arranging parts within the jib body 106 is limited. For this reason, a wire rope wound around a sheave provided at each end of a plurality of jib components is pushed and pulled by a jib telescopic cylinder in the jib body 106 to be more distal than the jib component 104 adjacent to the base jib 103 There arises a disadvantage that it is difficult to apply a wire rope type expansion / contraction mechanism that expands / contracts the adjacent jib component 105.
In particular, in the structure of the jib undulating and stretching device 100 disclosed in Patent Document 1, since the jib telescopic cylinder and the jib component 105 are connected to each other at the tip surface of the jib component 105, the jib component There is an inconvenience that another jib component is attached in a plug-in form on the tip side of 105 and cannot be further multistaged.
In the jib undulating expansion / contraction device 100 disclosed in Patent Document 1, the multi-stage jib expansion / contraction cylinder is used to make the stroke of the jib expansion / contraction cylinder, that is, the jib component 105 closer to the tip than the jib component 104 adjacent to the base jib 103. The extension stroke is guaranteed to be long enough, but the multistage jib extension cylinder itself is expensive, and even if a multistage jib extension cylinder is used, the wire rope is used together with the jib extension cylinder. Thus, there is a problem in that a long expansion / contraction stroke comparable to an expansion / contraction mechanism (hereinafter referred to as a wire rope type expansion / contraction mechanism) that expands and contracts a plurality of jib components cannot be obtained.

  As a wire rope type expansion / contraction mechanism for expanding / contracting a telescopic structure columnar body, for example, a boom structure as disclosed in Patent Document 2 is already known, and this technique is applied to a work machine including a telescopic structure columnar body. It is easy for those skilled in the art to use it as a jib expansion / contraction mechanism.

As a method of securing a space for installing a jib telescopic cylinder or a wire rope type telescopic mechanism inside the jib, for example, a jib hoisting cylinder may be arranged outside the jib body. If installed on the upper surface of the main body, there is a risk that the supplementary wire rope that spans from the boom to the jib may come into contact with the jib hoisting cylinder, and if the jib hoisting cylinder is installed on the lower surface of the jib main body, Inconveniences such as hooks and suspended loads coming into contact with the jib hoisting cylinder will occur.
In addition, even if the jib undulation cylinder is installed on any of the upper, lower, left, and right sides of the jib body, the force that pushes the jib component adjacent to the base jib out of the base jib is biased, so a bending moment that curves the jib body occurs. The stress acting on the jib body increases. Furthermore, the jib body is bent by this stress, and the tip of the jib moves from the jib neutral axis to either the top, bottom, left or right (radial direction about the jib neutral axis), and the lifting load applied to the jib tip becomes an eccentric load. Since a bending moment is generated, excessive stress is applied to the jib body, which may cause damage to the jib body. In addition, the force acting on one side of the jib body causes galling in the sliding part between the jib component adjacent to the base jib and the base jib, or the bending of the jib body becomes resistance and the undulation capability of the jib body decreases. There is a possibility.

Since the jib hoisting device disclosed in Patent Document 3 functions as a jib foot member provided on the left and right of the base of the jib, in a broad sense, a structure in which the jib hoisting cylinders are installed on the left and right of the jib. However, in the jib hoisting device disclosed in Patent Document 3, the jib foot member constituting a part of the base jib itself is a cylinder, and the bending load acting on the jib body is used as the jib foot member. It must be received by the cylinder. Although the cylinder can withstand the load in the compression direction, the cylinder is not structured to receive the load in the lateral direction, and receiving the load in the lateral direction may cause an oil seal or the like to be deformed to cause oil leakage or damage the cylinder.
In addition, since the jib foot member is a cylinder, there is a drawback in that when the expansion difference occurs between the left and right cylinders, the left and right inclinations are directly generated in the jib body by the difference in expansion.

  When swinging out the jib in the retracted state, the jib held on the lower surface of the boom of the work implement is swung out as it is, and the jib held on the side of the boom of the work implement is moved to the lower surface of the boom. The jib held on the lower surface of the boom of the work equipment may be swung out to the tip of the boom as it is, the swiveling work, and the side of the boom. The structure (twist mechanism) required for pivoting the base of the base jib to the tip of the boom so that the held jib can be moved to the lower surface of the boom and swingable in the vertical plane, and its mounting work Is already known from Patent Document 4 and the like.

  In addition, a technical idea that eliminates inconveniences such as torsion that occur in an object to be driven by communicating the oil chambers of two cylinders provided in parallel with each other to synchronize the operating states of the two cylinders, and a counter balance valve The prevention of inadvertent shortening of the piston rod, which is performed by using the back pressure control by means of, is already known from Patent Document 5 and the like.

JP 2013-43706 A (paragraphs 0023, 0006, 0009, 0028, FIG. 5, FIG. 9, FIG. 10, paragraphs 0022 to 0023, FIG. 6 to FIG. 7) Japanese Utility Model Publication No. 60-64991 (Fig. 1) Japanese Utility Model Publication No. 4-32398 (page 2, right column, lines 3 to 7; page 2, left column, lines 19 to 21; FIG. 1) JP 2011-131975 (paragraphs 0019 to 0021, FIGS. 1A to 1H) Japanese Utility Model Publication No. 60-22076 (page 2, left column, lines 41 to 43, page 2, right column, line 42 to page 2, left column, lines 34 to 36, FIG. 2)

  The object of the present invention is not to increase the weight of the jib, which causes a decrease in the strength of the jib or a decrease in lifting performance, but in various types including a multistage jib expansion cylinder and a wire rope type expansion mechanism. Ensuring sufficient space inside the jib to install the jib expansion and contraction mechanism to facilitate multi-stage and long strokes of the jib, as well as the occurrence of interference between the auxiliary winding wire rope and hook and the jib hoisting cylinder, In addition, the generation of force bias when pushing out the jib component adjacent to the base jib from the base jib and the resulting damage to the jib body, and the occurrence of galling in the sliding part between the jib component adjacent to the base jib and the base jib An object of the present invention is to provide a jib hoisting device for a working machine that can prevent the lowering of the hoisting ability of the jib main body due to the resistance caused by the curvature of the jib main body.

A jib hoisting device for a working machine according to the present invention includes a jib main body in which a plurality of jib components including a base jib pivotally attached to the tip of a boom are connected to each other by a telescopic structure, and one end to a jib component adjacent to the base jib. And the other end of the jib undulation cylinder attached to the base jib, and extending the adjacent jib component from the base jib by the extension operation of the jib undulation cylinder. A jib hoisting device for a working machine that swings out to the tip of a boom.
The jib hoisting cylinder is disposed on the left and right sides of the base jib and has one end attached to the adjacent jib component and the other end attached to the base jib.

The base jib is pivotally attached to the tip of the boom, and the rigging pulled out from the top end of the boom is fixed to the jib component adjacent to the base jib, and the movement of this jib component is restrained. When the two jib hoisting cylinders on the left and right of the base jib are attached to the jib component adjacent to the base jib and the other end is attached to the base jib, the jib components adjacent to the base jib will protrude from the base jib. The jib extends between the base jib and the jib component with the rigging secured.
The routing position of the rigging on the top surface of the boom tip is located above the pivot position of the base jib at the tip of the boom, and the anchoring position of the rigging and the tip of the boom in the jib component to which the rigging is secured The separation distance between the upper surface of the rigging and the position of the rigging is kept constant by the rigging, so that when the jib extends between the jib component that fastens the rigging and the base jib, it pivots to the tip of the boom. The worn jib swings in a vertical plane around the pivot position of the base jib at the tip of the boom due to the tension of the rigging, and is swung out toward the tip of the boom.
Since the two jib hoisting cylinders are installed on the left and right sides of the jib body, when the jib components adjacent to the base jib are projected from the base jib, it is the same as the case where the jib hoisting cylinder is arranged inside the base jib. The jib component adjacent to the base jib can be pushed out without any deviation in any direction with respect to the central axis of the jib body. Therefore, a bending moment for bending the jib body does not occur, and the jib body does not bend due to stress acting on the jib body. Therefore, due to the curvature of the jib, the jib tip moves from the jib neutral axis to either the top, bottom, left, or right (radial direction around the jib neutral axis), causing the lifting load applied to the jib tip to become eccentric, Inconvenient in that the jib body is damaged due to excessive stress, and that the sliding force between the jib components adjacent to the base jib and the base jib is caused by the force acting on one side of the jib body Occurrence of problems such as bending of the jib body and resistance of the jib body being lowered is prevented.
In addition, since the jib undulation cylinder is arranged on the left and right of the jib body having a telescopic structure in which a plurality of jib components are connected to be extendable, a sufficient space is secured inside the jib, and a multistage jib expansion cylinder Various types of jib expansion / contraction mechanism including a wire rope type expansion / contraction mechanism can be arranged inside the jib, and the jib component closer to the tip than the base jib, that is, the jib configuration fitted inside the base jib Since the element does not interfere with the jib hoisting cylinder, it is easy to increase the extension stroke by using multiple stages of jib, especially by using new stages of jib components inserted into the tip of the jib. Is possible.
Although it is configured to use two jib hoisting cylinders, the installation location is on the left and right sides of the base jib, so the jib body as a whole will be the front heavy weight distribution or excessive weight increase may occur. There will be no adverse effects on the strength of the jib body and boom when the jib body is extended, and the lifting performance (strength performance) of the jib body, and the installation location of the jib hoisting cylinder should be on the left and right sides of the base jib Therefore, interference between the auxiliary winding wire rope or hook and the jib hoisting cylinder is also prevented.
Since the bending load acting on the jib body is supported by the base jib configured independently of the jib hoisting cylinder and the jib components adjacent to the base jib, the lateral load and the bending load act on the jib hoisting cylinder, and oil seals etc. Problems such as oil leakage and damage to the jib hoisting cylinder due to deformation of the jib are also prevented, and the tilting of the jib body to the left and right due to the difference in elongation between the left and right jib hoisting cylinders is also eliminated.

  Furthermore, it is good also as a structure provided with the tuning apparatus which synchronizes the operating state of the jib hoisting cylinder arrange | positioned at the right and left of a base jib.

  When such a configuration is applied, it is possible to synchronize the operating states of the left and right jib hoisting cylinders, so that a difference in pressure between the oil chambers in the left and right jib hoisting cylinders and a dimensional difference due to the cylinder protrusion amount occur. Can be prevented.

  This tuning device can be constituted by, for example, an equalizer link interposed between one end of each jib hoisting cylinder and a jib component adjacent to the base jib or between the other end of each jib hoisting cylinder and the base jib. it can.

  When such a configuration is applied, it is possible to synchronize the operating state of the left and right jib undulation cylinders by changing the posture of the equalizer link. Is prevented from occurring.

As an equalizer link that functions as a tuning device, an equalizer link provided with a cylinder mounting portion at each of two positions that are symmetrical with respect to the center line is particularly suitable. When this type of equalizer link is used, the center portion of the equalizer link is pivotally mounted along the central axis of the jib body on the jib component adjacent to the base jib or on the base jib so as to be rotatable in a horizontal plane. One end or the other end of each jib hoisting cylinder is attached to a jib component or base jib adjacent to the base jib via an equalizer link.
In other words, when attaching an equalizer link to a jib component adjacent to the base jib, the center portion of the equalizer link can be rotated in a horizontal plane on the jib component adjacent to the base jib along the central axis of the jib body. The left and right jib undulation cylinders are pivotally attached to each of the two cylinder mounting portions on the equalizer link, and the ends of the left and right jib undulation cylinders are connected to each other via the equalizer link. When attaching an equalizer link to the base jib while attaching to the jib component adjacent to the base jib, the center of the equalizer link can be rotated in a horizontal plane on the base jib along the central axis of the jib body. The other ends of the left and right jib hoisting cylinders are connected to the two series on the equalizer link. And pivotally connected to each of the da attaching portion is that attaching the other end of the left and right of the jib derricking cylinder via the equalizer link Besujibu.

Even if the equalizer link is attached to the jib component adjacent to the base jib or the equalizer link is attached to the base jib, the effect that this equalizer link has is the same. The operation of the equalizer link will be described by taking as an example the case where the equalizer link is attached.
First, if the projections of the left and right jib undulation cylinders cannot be synchronized when the jib is swung out or expanded, the overall length of either the left or right jib undulation cylinder will be relatively long, and the total length of the other jib undulation cylinder will be relatively In that case, the equalizer link attached to the base jib at the position along the central axis of the jib body with the other end of each of the left and right jib hoisting cylinders pivoted, The cylinder mounting part pivoting the jib undulation cylinder on the side where the overall length is relatively long is moved away from the base jib tip and approaches the base part of the base jib and the overall length is relatively short. The left and right jib undulating cylinders are rotated by rotating the cylinder mounting part pivotally attached to the jib undulating cylinder away from the base part of the base jib and approaching the tip of the base jib. To absorb the dimensional difference, smoothing the pressing load acting on the left and right of the jib derricking cylinder. The pressure load acting on the left and right jib hoisting cylinders is smoothed because the cylinder attachment part pivotally attaches the other end of the left and right jib hoisting cylinders to each of two symmetrical positions across the center line of the equalizer link. By extending the equalizer link horizontally along the central axis of the jib body, the equalizer link extends from the line of action of the force along the axis of the right jib undulating cylinder toward the center that is the center of rotation of the equalizer link. The length of the vertical foot (the length of the arm of the moment) and the length of the vertical foot extended from the line of action of the force along the axis of the left jib undulation cylinder toward the center that is the center of rotation of the equalizer link This is because the (moment arm length) is made equal in the neutral state.
Therefore, even when a situation occurs in which the protruding amounts of the left and right jib undulation cylinders cannot be synchronized when the jib is swung out and extended, there is no imbalance in the pressing load acting on the left and right jib undulation cylinders. Damage to the jib hoisting cylinder due to an excessive load acting on one side and bending of the jib in the left-right direction due to variations in the protruding amount of the left and right jib hoisting cylinders are prevented in advance.
Also, even when an external force that swings the tip of the jib to the left or right due to the tilt of the chassis during the lifting work using the swinging jib, the force is evenly distributed to the left and right jib hoisting cylinders. Even when an external force that swings the tip of the jib from side to side is applied during lifting work using the swinging jib, there is no significant imbalance in the pressing load acting on the left and right jib undulation cylinders. Damage to the jib undulation cylinder due to a heavy load is prevented.

Here, each of the two cylinder mounting portions in the equalizer link is preferably arranged so as to be offset from the center portion of the equalizer link along the center line of the jib body toward the direction away from each jib hoisting cylinder. .
In other words, when the equalizer link is attached to the jib component adjacent to the base jib, the two cylinder mounting portions are offset toward the tip side of the jib body, while the equalizer link is attached to the base jib. That is, the two cylinder mounting portions are offset toward the base side of the base jib.

Even if the equalizer link is attached to the jib component adjacent to the base jib or the equalizer link is attached to the base jib, the effect that this equalizer link has is the same. The operation of the equalizer link to which this offset structure is applied will be described by taking as an example the case where the equalizer link is attached to.
Even when such a configuration is applied, as in the case described above, when the situation in which the protruding amounts of the left and right jib hoisting cylinders cannot be synchronized during jib swinging and expansion / contraction, the total length of either the left or right jib hoisting cylinder is It becomes relatively long and the overall length of the other jib hoisting cylinder becomes relatively short. As a result, the equalizer link mounted on the base jib with the other ends of the left and right jib hoisting cylinders pivoted is the jib hoisting on the side where the overall length is relatively longer with the center as the center of rotation. The cylinder mounting part pivotally attached to the cylinder moves away from the tip of the base jib and approaches the base part of the base jib, and the cylinder mounting part pivotally attached to the jib hoisting cylinder on the side where the overall length is relatively short is separated from the base part of the base jib. Rotate in the direction approaching the tip of the base jib.
However, in this case, each of the two cylinder mounting portions in the equalizer link is offset from the center portion of the equalizer link along the central axis of the jib body toward the base portion of the jib, so that the tip of the base jib The cylinder mounting part moved away from the base jib in the direction approaching the base jib base moves inward, i.e., in the direction approaching the central axis of the jib body, and moved away from the base jib base in the direction approaching the base jib tip. The cylinder mounting portion moves outside, that is, in a direction away from the central axis of the jib body.
The reason for this is that, under such an offset condition, each of the two cylinder mounting portions has a center portion of the equalizer link out of a circular trajectory passing through each of the two cylinder mounting portions around the center portion of the equalizer link, that is, It moves only along the arc trajectory of the portion closer to the base of the base jib than the center of rotation, and in the section of this arc trajectory, the closer the cylinder mounting part is to the base side of the base jib, the closer to the central axis of the jib body, This is because the closer the cylinder mounting portion is to the tip side of the base jib, the farther from the central axis of the jib body.
Therefore, the length of the foot of the perpendicular line (the length of the arm of the moment) that extends from the line of action of the force along the axis of the jib hoisting cylinder on the relatively long side toward the center that is the center of rotation of the equalizer link Is the length of the leg of the perpendicular (arm of moment) extending from the line of action of the force along the axis of the jib hoisting cylinder on the side where the overall length is relatively shortened toward the center that is the center of rotation of the equalizer link The length).
Here, since the magnitude of the pressing force acting along the axis of the left and right jib undulation cylinders is basically the same, the rotational force acting on the equalizer link is the jib undulation on the side where the overall length is relatively long. Jib undulation on the side where the overall length is relatively short in the opposite direction compared to the rotational force (rotational force applied via the arm of the shorter moment) from the cylinder mounting part on the side where the cylinder is connected The rotational force (rotational force applied through the arm of the longer moment) applied from the cylinder mounting portion on the side where the cylinder is connected becomes larger.
Therefore, the equalizer link is located on the side where the cylinder mounting part pivoting the jib hoisting cylinder on the side where the overall length is relatively short is spaced from the tip of the base jib and approaches the base part of the base jib and the overall length is relatively long The cylinder mounting part pivotally attached to the jib hoisting cylinder is rotated away from the base part of the base jib so as to approach the tip of the base jib. The rotation of the equalizer link causes the jib on the side whose overall length is relatively short. A correction is made to extend the undulation cylinder and to reduce the jib undulation cylinder on the side where the overall length is relatively long, and the deviation of the projection amounts of the left and right jib undulation cylinders is automatically eliminated.

  Further, in the two jib hoisting cylinders, the oil chambers on the side to which the working oil is supplied when the jib components adjacent to the base jib protrude from the base jib may be connected to each other by a connecting pipe.

By applying such a configuration, the magnitude of the pressing force acting along the axes of the left and right jib undulation cylinders can be reliably equalized.
In particular, when used in combination with a configuration in which each of the cylinder mounting portions at the two positions in the equalizer link is offset toward the direction away from each jib undulation cylinder, along the axis of the left and right jib undulation cylinders As a result, the size of the jib hoisting cylinder on the side with the shorter overall length is extended to reduce the size of the jib hoisting cylinder on the side with the longer overall length. The correction to be performed is performed with high accuracy, and the synchronization deviation of the protrusion amounts of the left and right jib undulation cylinders can be eliminated at a higher level.

  Further, as the tuning device, a flow divider that supplies hydraulic oil evenly to the two jib hoisting cylinders may be used instead of the equalizer link described above.

  Since the hydraulic oil is evenly supplied to the left and right jib undulation cylinders, the occurrence of synchronization deviation of the protruding amounts of the left and right jib undulation cylinders can be prevented.

  Furthermore, in addition to the configuration in which the equalizer link is used as a tuning device, a flow divider that supplies hydraulic oil equally to the two jib hoisting cylinders may be used in combination.

  Since hydraulic oil is evenly supplied to the left and right jib hoisting cylinders, it is possible to prevent out-of-sync deviations in the protruding amounts of the left and right jib hoisting cylinders, and the tip of the jib is left and right. Even when a shaking external force is applied, the equalizer link prevents imbalance of the pressing load acting on the left and right jib undulation cylinders, so damage to the jib undulation cylinder due to excessive load acting on one side of the jib undulation cylinder Can be prevented in advance.

In the jib hoisting device of the working machine according to the present invention, the jib hoisting cylinder is arranged on the left and right of the base jib, and one end thereof is attached to the jib component adjacent to the base jib, and the other end is attached to the base jib. The jib component adjacent to the base jib can be pushed out without any deviation in any direction with respect to the central axis of the jib body. Therefore, a bending moment for bending the jib body does not occur, and the jib body does not bend due to stress acting on the jib body. Therefore, due to the curvature of the jib, the jib tip moves from the jib neutral axis to either the top, bottom, left, or right (radial direction around the jib neutral axis), causing the lifting load applied to the jib tip to become eccentric, Inconvenient in that the jib body is damaged due to excessive stress, and that the sliding force between the jib components adjacent to the base jib and the base jib is caused by the force acting on one side of the jib body Occurrence of problems such as bending of the jib body and resistance of the jib body being lowered is prevented.
In addition, since the jib undulation cylinder is arranged on the left and right of the jib body having a telescopic structure in which a plurality of jib components are connected to be extendable, a sufficient space is secured inside the jib, and a multistage jib expansion cylinder Various types of jib expansion / contraction mechanism including a wire rope type expansion / contraction mechanism can be arranged inside the jib, and the jib component closer to the tip than the base jib, that is, the jib configuration fitted inside the base jib Since the element does not interfere with the jib hoisting cylinder, it is easy to increase the extension stroke by using multiple stages of jib, especially by using new stages of jib components inserted into the tip of the jib. Is possible.
Although it is configured to use two jib hoisting cylinders, the installation location is on the left and right sides of the base jib, so the jib body as a whole will be the front heavy weight distribution or excessive weight increase may occur. There will be no adverse effects on the strength of the jib body and boom when the jib body is extended, and the lifting performance (strength performance) of the jib body, and the installation location of the jib hoisting cylinder should be on the left and right sides of the base jib Therefore, interference between the auxiliary winding wire rope or hook and the jib hoisting cylinder is also prevented.
Since the bending load acting on the jib body is supported by the base jib constructed independently of the jib hoisting cylinder and the jib components adjacent to the base jib, the lateral load and bending load act on the jib hoisting cylinder and the oil Problems such as oil leakage and damage to the jib hoisting cylinder due to deformation of the seal and the like are also prevented, and the tilting of the jib body to the left and right due to the difference in elongation between the left and right jib hoisting cylinders is eliminated.

  Furthermore, in the case of a configuration provided with a tuning device that synchronizes the operating state of the jib hoisting cylinders arranged on the left and right of the base jib, it becomes possible to synchronize the operating state of the left and right jib hoisting cylinders. It is possible to prevent the pressure difference between the oil chambers in the left and right jib hoisting cylinders and the dimensional difference in the cylinder protrusion amount.

  For example, when a tuning device is configured by an equalizer link interposed between one end of each jib hoisting cylinder and a jib component adjacent to the base jib or between the other end of each jib hoisting cylinder and the base jib. Therefore, the change in the posture of the equalizer link prevents the dimensional difference due to the pressure difference and the protruding amount in the oil chamber in the left and right jib hoisting cylinders.

In particular, in the case of using an equalizer link that has a cylinder mounting portion at each of two positions that are symmetric with respect to the center line of the equalizer link, the amount of protrusion of the left and right jib undulating cylinders is synchronized when the jib is extended and extended. If the overall length of the left or right jib undulation cylinder is relatively long and the other jib undulation cylinder is relatively short, the equalizer link is connected to the side of the jib undulation cylinder whose length is relatively long. The cylinder mounting part pivotally attached to the base jib is separated from the base jib tip and approaches the base jib base, and the cylinder mounting part pivotally attached to the jib hoisting cylinder on the side where the overall length is relatively short is separated from the base jib base. Rotate in a direction approaching the tip of the base jib (when an equalizer link is attached to the base jib) or all The cylinder mounting part that pivots the jib hoisting cylinder on the side where the relative length is longer is separated from the base of the jib body, and the cylinder mounting part that pivots the jib hoisting cylinder on the side where the overall length is relatively shorter is the base jib. By rotating in the direction approaching the base of the base (when the equalizer link is attached to the jib component adjacent to the base jib), the dimensional difference between the left and right jib hoisting cylinders is absorbed, and the pressure load acting on the left and right jib hoisting cylinders is absorbed. Smooth. Therefore, even when a situation occurs in which the protruding amounts of the left and right jib undulation cylinders cannot be synchronized when the jib is swung out and extended, there is no imbalance in the pressing load acting on the left and right jib undulation cylinders. It is possible to prevent the jib bending in the left-right direction due to the damage of the jib hoisting cylinder due to the excessive load acting on one side and the variation in the protruding amount of the left and right jib hoisting cylinders.
Also, even when an external force that swings the tip of the jib to the left or right due to the tilt of the chassis during the lifting work using the swinging jib, the force is evenly distributed to the left and right jib hoisting cylinders. Even when an external force that swings the tip of the jib from side to side is applied during lifting work using the swinging jib, there is no significant imbalance in the pressing load acting on the left and right jib undulation cylinders. Damage to the jib undulation cylinder due to a heavy load is prevented.

  In particular, when each of the two cylinder mounting portions in the equalizer link is offset from the center portion of the equalizer link along the center line of the jib body toward the direction away from each jib undulating cylinder, the total length is relatively The length of the leg of the perpendicular (the length of the arm of the moment) extending from the line of action of the force along the axis of the jib undulation cylinder on the longer side to the center that is the center of rotation of the equalizer link is Compared to the length of the leg of the perpendicular (the length of the arm of the moment) extending from the line of action of the force along the axis of the jib undulation cylinder on the relatively shortened side toward the center that is the center of rotation of the equalizer link Become shorter. Since the magnitude of the pressing force acting along the axis of the left and right jib hoisting cylinders is basically the same, as a result, the rotational force acting on the equalizer link is the jib on the side where the overall length is relatively long. The jib hoisting cylinder on the side whose overall length is relatively short in the opposite direction compared to the rotating force (rotating force given through the shorter arm) applied from the cylinder mounting part on the side where the hoisting cylinder is connected The rotational force (rotational force applied through the longer arm) applied from the cylinder mounting portion on the side to which is connected becomes larger. Therefore, the equalizer link is located on the side where the cylinder mounting part pivoting the jib hoisting cylinder on the side where the overall length is relatively short is spaced from the tip of the base jib and approaches the base part of the base jib and the overall length is relatively long The cylinder mounting part that pivots the jib undulation cylinder of the cylinder rotates away from the base jib base and approaches the tip of the base jib (when the equalizer link is attached to the base jib), or the overall length is relatively short The cylinder mounting part pivoting the jib hoisting cylinder on the other side is separated from the base part of the base jib, and the cylinder mounting part pivoting the jib hoisting cylinder on the side where the overall length is relatively long approaches the base part of the base jib. Rotates (when an equalizer link is attached to the jib component adjacent to the base jib). The rotation of the equalizer link makes a correction to extend the jib undulation cylinder on the side having a relatively short overall length and to reduce the jib undulation cylinder on the side having a relatively long overall length. Therefore, the deviation of the protrusion amount of the jib undulation cylinder is automatically eliminated.

Further, in the two jib hoisting cylinders, when the jib components adjacent to the base jib are protruded from the base jib, the oil chambers on the side to which the hydraulic oil is supplied are connected to each other by connecting pipes. The magnitude of the pressing force acting along the axis of the jib hoisting cylinder can be surely equalized.
In particular, the left and right jibs should be used in combination with a configuration in which each of the two cylinder mounting portions of the equalizer link is offset from the center portion of the equalizer link in a direction away from each jib hoisting cylinder. As a result of surely equalizing the amount of pressing force acting along the axis of the undulation cylinder, the side where the overall length is relatively long by extending the jib undulation cylinder on the side where the overall length is relatively short The correction for reducing the size of the jib undulation cylinder is performed with high accuracy, and the synchronization deviation of the protrusion amounts of the left and right jib undulation cylinders can be eliminated at a higher level.

  Further, as a tuning device, instead of the equalizer link described above, a flow divider that supplies hydraulic oil evenly to the left and right jib undulation cylinders may be used. Therefore, the hydraulic oil is supplied evenly, so that it is possible to prevent occurrence of synchronization deviation of the protrusion amounts of the left and right jib undulation cylinders.

  Furthermore, in addition to the configuration using the equalizer link as a tuning device, a flow divider that supplies hydraulic oil evenly to the left and right jib undulation cylinders may be used in combination. Even when the hydraulic oil is supplied evenly, it is possible to prevent the out-of-synchronization of the protruding amount of the left and right jib hoisting cylinders, and even when an external force that shakes the tip of the jib to the left and right acts. Since the equalizer link prevents imbalance between the pressing loads acting on the left and right jib undulating cylinders, it is possible to prevent damage to the jib undulating cylinder due to an excessive load acting on one side of the jib undulating cylinder.

It is the top view shown in the state where the jib component adjacent to a base jib was stored in the base jib about the jib raising and lowering device of the working machine in one embodiment to which the present invention is applied. It is the perspective view shown in the state which accommodated the jib component adjacent to a base jib about the jib raising / lowering apparatus of the working machine in the embodiment in the base jib. It is the perspective view shown in the state which made the jib component adjacent to a base jib protrude from the base jib about the jib raising / lowering apparatus of the working machine in the embodiment. It is the perspective view which expanded and showed a part of jib raising / lowering apparatus of the working machine in the embodiment. It is sectional drawing which expanded and showed a part of jib raising / lowering apparatus of the working machine in the embodiment. FIG. 6 is an operation principle diagram showing the configuration and mounting state of the equalizer link that constitutes a part of the jib undulation device of the working machine according to the embodiment, and the operation principle diagram thereof, among which the equalizer link is neutral in FIG. FIG. 6B shows a state when the equalizer link is rotated in the counterclockwise direction from the neutral position. It is the hydraulic circuit figure which showed the outline | summary of the hydraulic circuit of the jib raising / lowering apparatus of the working machine in the embodiment. It is the hydraulic circuit figure which showed the outline | summary of the hydraulic circuit of the jib raising / lowering apparatus of the working machine in other one embodiment. This is an operation principle diagram showing the general configuration of the jib hoisting device of the working machine that extends the full length of the jib by extending the jib hoisting cylinder and swinging out the jib to the tip of the boom and the operating principle of the jib swinging. is there.

  Next, several embodiments to which the present invention is applied will be specifically described with reference to the drawings.

FIG. 1 is a plan view showing a jib undulation device for a working machine according to an embodiment to which the present invention is applied in a state in which jib components adjacent to the base jib are housed in the base jib, and FIG. FIG. 3 is a perspective view showing a state in which the jib components adjacent to the base jib are housed in the base jib, and FIG. 3 is a state in which the jib components adjacent to the base jib are projected from the base jib in the working machine jib hoisting device in the same embodiment. 4 is an enlarged perspective view showing a part of the jib undulation device of the working machine in the embodiment, and FIG. 5 is an enlarged view of a part of the jib undulation device of the working machine in the embodiment. It is sectional drawing shown.
FIG. 6 is an operation principle diagram showing the configuration, attachment state, and operation principle of the equalizer link that constitutes a part of the jib undulation device of the working machine according to the embodiment. Of these, FIG. FIG. 6 shows the state when the equalizer link is in the neutral position, and FIG. 6B shows the state when the equalizer link rotates counterclockwise from the neutral position.
The attachment of the jib to the boom of the working machine is the same as that of the conventional example shown in FIG. 9, and therefore the attachment of the jib to the boom and the swinging operation of the jib will be described with reference to FIG.

The main part of the jib 1 of this embodiment is, as shown in FIGS. 1 to 3, a boom 102 (hereinafter referred to as the following) of a work machine as illustrated in FIG. 9 so as to be swingable in a vertical plane. Base jib 2 pivotally mounted at its base 2a, 2a at the tip of boom 102), jib component 3 adjacent to base jib 2 (hereinafter simply referred to as jib component 3), and adjacent jib component 3 The tip end side jib component 4 and the tip end side jib component 4 ′ adjacent to the jib component 4 are connected to each other in a telescopic manner so as to be telescopically structured.
Among these, on the upper surface of the distal end portion of the jib component 3 adjacent to the base jib 2, a base portion 2a that is pulled out from the distal upper surface side of the boom 102 and attached to the pivot position (position T2 in FIG. 9) of the base jib 2; A fixed-length cord 107 (hereinafter simply referred to as the cord 107) as shown in FIG. 9 led to the jib component 3 via a position above the position 2a (position T1 in FIG. 9) is fixed. Rigging attachment portions 6 and 6 are provided integrally with the jib component 3.

In this embodiment, the drive source for expanding and contracting the jib component 3 adjacent to the base jib 2 relative to the base jib 2 is a jib hoisting cylinder 7L disposed on the left and right sides of the base jib 2 so as to sandwich it. And a jib hoisting cylinder 7R.
Then, one end (the left end in FIGS. 1 to 3) of the jib hoisting cylinders 7L and 7R is placed in a horizontal plane via brackets 8L and 8R that are provided on the left and right of the central portion of the jib component 3 adjacent to the base jib 2. The jib hoisting cylinders 7 </ b> L and 7 </ b> R are attached to the center of the jib component 3 in a freely rotatable state, while the other ends (right ends in FIGS. 1 to 3) are jib hoisting cylinders arranged on the left and right of the base jib 2. The base jib 2 is attached to the left and right of a substantially central portion via an equalizer link 9 that functions as a tuning device for synchronizing the operating states of 7L and 7R.

  In this embodiment, the piston rod side of the jib hoisting cylinders 7L and 7R is attached to the jib component 3 adjacent to the base jib 2 as one end, and the tube side of the jib hoisting cylinders 7L and 7R is attached to the base jib 2 as the other end. However, on the contrary, the tube side of the jib hoisting cylinders 7L and 7R is attached to the jib component 3 adjacent to the base jib 2 with the tube side as one end and the piston rod side of the jib hoisting cylinders 7L and 7R is used as the other end. You may make it attach to the base jib 2. FIG.

  As shown in FIG. 6A, the equalizer link 9 is for pivotally attaching the other ends of the jib undulating cylinders 7L and 7R to each of two positions that are symmetrical with respect to the center line Lx1 of the equalizer link 9. Cylinder mounting portions 10L and 10R.

  In particular, in the equalizer link 9 of this embodiment, the cylinder mounting portions 10L and 10R are arranged along the central axis Lx2 of the jib body 5 from the center portion Q common to the rotation center of the equalizer link 9. They are arranged offset in the direction away from 7L and 7R, that is, in the direction toward the right in FIG. 1 and FIG.

The equalizer link 9 is pivotally attached to the center portion Q in the longitudinal direction on the base jib 2 so as to be rotatable on the base jib 2 in a horizontal plane, and is a center common to the center of rotation. The part Q is located along the central axis Lx2 of the jib body 5 as shown in FIG.
Then, as shown in FIG. 1, the other end of the jib hoisting cylinder 7L is pivotally attached to the cylinder mounting portion 10L of the equalizer link 9 so that the other end of the jib hoisting cylinder 7L is rotatable in the horizontal plane, and the other end of the jib hoisting cylinder 7R is in the horizontal plane. Is pivotally attached to the cylinder mounting portion 10R of the equalizer link 9 so as to be rotatable.
In this embodiment, as shown in FIGS. 2 and 3, the equalizer link 9 is installed in the vicinity of the center of the base jib 2 in the thickness direction (vertical direction when the jib is laid down), and is formed into a cylindrical shape having a rectangular cross section. The left and right side walls of the formed base jib 2 are provided with slits that allow the left and right end portions to change as the equalizer link 9 rotates, and the left and right end portions of the equalizer link 9 having the cylinder mounting portions 10L and 10R Although it is made to protrude from the slit to the left and right sides of the base jib 2, the equalizer link 9 can be externally attached to the upper surface and the lower surface of the base jib 2.

In this embodiment, rectangular frame-shaped supporters 12L and 12R for holding the jib hoisting cylinders 7L and 7R are further provided on both the left and right sides of the base jib 2 at a position slightly shifted to the base side. .
As shown in FIG. 5, the supporters 12 </ b> L and 12 </ b> R are, for example, a combination of an L-shaped metal plate 13 and two flat metal plates 14 and 15 facing each surface of the metal plate 13. A main body portion 16 formed by screwing four resin plates 17 having both wear resistance and sliding property on the inner side of the four wall surfaces of the formed cylindrical body, and formed on the main body portion 16. A decorative frame 18 having a rectangular opening having a size substantially equal to the inner dimension of the opening is fixed to each other, and the leg portions 16a and 16a of the main body 16 and one side of the decorative frame 18 are configured. It is fixed to the side wall portion of the base jib 2 through the portion 18a, and is arranged so as to face these tube portions with a certain gap between the tube portions of the jib hoisting cylinders 7L and 7R. Due to the four resin plates 17 Jib derricking cylinder 7L, jib hoist cylinder 7L without interfering axial movement of 7R, so as to prevent holds 7R, its bending.
The vicinity of the other end of the jib hoisting cylinders 7L and 7R moves slightly in and out with the base jib 2 sandwiched by the rotation of the equalizer link 9, and changes its position in the left-right direction in FIG. The separation distance between 17 is slightly larger than the separation distance between the resin plates 17 and 17 facing vertically.
Thus, the supporters 12L and 12R are provided, and the jib hoisting cylinders 7L and 7R are supported at three points, that is, the jib component 3 side attachment portion (one end), the base jib 2 side attachment portion (the other end), and the central portion. As a result, the apparent buckling strength of the jib undulation cylinders 7L and 7R can be improved. Therefore, it is possible to make a measurement design in which the substantial buckling strength of the jib undulation cylinders 7L and 7R is relatively lowered. Therefore, the jib hoisting cylinders 7L and 7R can be reduced in weight.
The supporters 12L and 12R that hold the intermediate portions of the jib hoisting cylinders 7L and 7R may be omitted, but in that case, it is necessary to give sufficient buckling strength to the jib hoisting cylinders 7L and 7R themselves. Since the secondary moment of the cross section needs to be increased due to an increase in the tube thickness or the like, the jib hoisting cylinders 7L and 7R are relatively larger and heavier than those of the embodiment.

  The jib hoisting device 11 in this embodiment is generally constituted by jib hoisting cylinders 7L and 7R and an equalizer link 9.

  FIG. 7 is a hydraulic circuit diagram showing an outline of the hydraulic circuit 19 in the jib hoisting device 11 of the working machine according to the embodiment.

  P1 and P2 are input / output ports of the hydraulic circuit 19, and are connected to two input / output ports of a three-way switching valve (not shown) (hereinafter simply referred to as a three-way switching valve) installed on the work machine side.

  A pipe S1 connected to the input / output port P1 is connected to the piston rod side oil chamber 7Lp of the jib hoisting cylinder 7L via a pipe extending in the axial direction inside the piston rod of the jib hoisting cylinder 7L and exiting outside in front of the piston. The pipe S1 ′ branched from the pipe S1 is connected to the piston rod of the jib hoisting cylinder 7R via a pipe extending in the axial direction inside the piston rod of the jib hoisting cylinder 7R and exiting outward before the piston. It is connected to the side oil chamber 7Rp.

  On the other hand, the pipe line S2 connected to the input / output port P2 is the anti-piston rod of the jib hoisting cylinder 7R through the counter balance valve 20R of the jib hoisting cylinder 7R and the pipe line passing through the piston rod of the jib hoisting cylinder 7R in the axial direction. The pipe S2 ′ connected to the side oil chamber 7Rr and branched from the pipe S2 is connected to the counter balance valve 20L of the jib hoisting cylinder 7L and the pipe passing through the piston rod of the jib hoisting cylinder 7L in the axial direction. It is connected to the anti-piston rod side oil chamber 7Lr of the jib hoisting cylinder 7L.

The counter balance valve 20R of the jib hoisting cylinder 7R is a piston which is an oil chamber on the side to which hydraulic oil is supplied when the jib component 3 adjacent to the base jib 2 is drawn into the base jib 2 and the jib body 5 is contracted and turned back. By detecting the pressure rise of the hydraulic oil supplied to the rod side oil chamber 7Rp, that is, the pressure rise of the hydraulic oil in the pipe line S1 ′, the hydraulic oil is projected when the jib component 3 adjacent to the base jib 2 is projected from the base jib 2. This is a counter balance valve that opens the pipeline S2 that supplies hydraulic oil to the oil chamber 7Rr, which is the oil chamber to which oil is supplied, and allows discharge of the hydraulic oil from the oil chamber 7Rr. The counter balance valve 20R is in a state where the pressure in the pipe line S1 ′ is lower than a specified value, that is, positively enters the piston rod side oil chamber 7Rp of the jib hoisting cylinder 7R by an explicit switching operation of the three-way switching valve. In a situation where the hydraulic oil is supplied and the swing-back operation of the jib body 5 is not performed, for example, in a situation where the three-way switching valve is held in the neutral position, the anti-piston rod side oil chamber of the jib hoisting cylinder 7R It prevents the hydraulic oil from leaking from 7Rr and ensures the posture of the jib body 5 during the load hanging work.
Similarly, the counter balance valve 20L of the jib hoisting cylinder 7L is provided with an oil chamber on the side to which hydraulic oil is supplied when the jib component 3 adjacent to the base jib 2 is drawn into the base jib 2 and the jib body 5 is reduced and swung back. When the jib component 3 adjacent to the base jib 2 is projected from the base jib 2 by detecting the pressure rise of the hydraulic oil supplied to the piston rod side oil chamber 7Lp, that is, the pressure rise of the hydraulic oil in the pipe line S1. This is a counter balance valve that opens the pipeline S2 ′ that supplies the hydraulic oil to the oil chamber 7Lr, which is the oil chamber to which the hydraulic oil is supplied, and allows the hydraulic oil to be discharged from the oil chamber 7Lr. The counter balance valve 20L is activated in the piston rod side oil chamber 7Lp of the jib hoisting cylinder 7L in a state where the pressure in the pipe line S1 is lower than a predetermined value, that is, by an explicit switching operation of the three-way switching valve. In a situation where oil is supplied and the swing-back operation of the jib body 5 is not performed, for example, in a situation where the three-way switching valve is held in the neutral position, the anti-piston rod side oil chamber 7Lr of the jib hoisting cylinder 7L This prevents the hydraulic oil from leaking out of the cylinder and secures the posture of the jib body 5 during the load lifting operation.

In addition, the anti-piston rod side oil chamber 7Rr of the jib hoisting cylinder 7R and the anti-piston rod side oil chamber 7Lr of the jib hoisting cylinder 7L are connected to a pipe passing through the piston rod of the jib hoisting cylinder 7R and the piston rod of the jib hoisting cylinder 7L. The pipes that pass through are connected to each other by connecting with a connecting pipe S3.
When the connecting pipe S3 is damaged at the connecting part between the pipe passing through the piston rod of the jib hoisting cylinder 7R and the connecting pipe S3, the anti-piston rod side oil chamber 7Rr of the jib hoisting cylinder 7R is damaged. When a fuse valve 21R for preventing leakage of hydraulic oil is installed and the connecting line S3 is damaged at the connecting part between the connecting line S3 and the pipe passing through the piston rod of the jib hoisting cylinder 7L. A fuse valve 21L for preventing leakage of hydraulic oil from the anti-piston rod side oil chamber 7Lr of the jib hoisting cylinder 7L is provided.
The fuse valve 21L is provided with a throttle (small passage hole), and when the flow rate passing through the fuse valve 21L is equal to or less than the set value, the pressure in the anti-piston rod side oil chamber 7Lr of the jib hoisting cylinder 7L and the communication line S3 is reduced. The deviation does not exceed the spring force of the fuse valve 21L, and the fuse valve 21L is held open. If the flow rate passing through the fuse valve 21L exceeds the set value due to the breakage of the communication line S3, the pressure between the anti-piston rod side oil chamber 7Lr of the jib hoisting cylinder 7L and the communication line S3 is reduced by the flow resistance caused by the restriction. When a deviation occurs and the pressure deviation exceeds the spring force of the fuse valve 21L, the fuse valve 21L is closed to prevent leakage of hydraulic oil from the anti-piston rod side oil chamber 7Lr of the jib hoisting cylinder 7L. Similarly, the fuse valve 21R is also provided with a throttle, and when the flow rate passing through the fuse valve 21R is equal to or less than the set value, the pressure deviation between the anti-piston rod side oil chamber 7Rr of the jib hoisting cylinder 7R and the connecting pipe line S3. Does not exceed the spring force of the fuse valve 21R, and the fuse valve 21R is held open. When the flow rate passing through the fuse valve 21R exceeds the set value due to the breakage of the communication line S3, the pressure between the anti-piston rod side oil chamber 7Rr of the jib hoisting cylinder 7R and the communication line S3 is caused by the flow resistance caused by the throttle. When a deviation occurs and the pressure deviation exceeds the spring force of the fuse valve 21R, the fuse valve 21R is closed to prevent leakage of hydraulic oil from the anti-piston rod side oil chamber 7Rr of the jib hoisting cylinder 7R.

  The actual mounting state of the counter balance valve 20L, the counter balance valve 20R, the communication line S3, the fuse valve 21R, and the fuse valve 21L is as shown in FIG.

  Next, the function and operation of the jib hoisting device 11 in this embodiment will be specifically described.

  When swinging out the jib body 5 in the contracted state, the bases 2a and 2a of the base jib 2 are first pivotally attached to the tip of the boom 102 so that the jib body 5 can swing within a vertical plane, as in the prior art. Then, a fixed-length rigging composed of two left and right tension rods drawn out from the upper surface of the tip of the boom 102 and guided from above the pivot positions 2a, 2a of the base jib 2 with respect to the boom 102 ( The tension rod 107 is fixed to the right and left rigging attachments 6 and 6 provided at the tip of the jib component 3 adjacent to the base jib 2, and the movement of the jib component 3 is the length of this rigging element 107. (See FIG. 9).

  Next, a three-way switching valve (not shown) on the work machine side is operated to start supplying hydraulic oil to the input / output port P2 of the hydraulic circuit 19, and at the same time, the input / output port P1 is opened.

Then, the hydraulic oil supplied to the input / output port P2 passes through the pipe S2, the counter balance valve 20R, and the piston rod of the jib hoisting cylinder 7R in the axial direction, and the anti-piston rod side of the jib hoisting cylinder 7R. The jib hoisting cylinder enters the oil chamber 7Rr and projects the piston rod of the jib hoisting cylinder 7R through the pipe S2 ′, the counter balance valve 20L, and the pipe rod passing through the piston rod of the jib hoisting cylinder 7L in the axial direction. It enters the 7L anti-piston rod side oil chamber 7Lr, and projects the piston rod of the jib hoisting cylinder 7L.
Further, the hydraulic oil in the piston rod side oil chamber 7Rp of the jib hoisting cylinder 7R whose volume has been reduced by the protrusion of the piston rod extends in the axial direction inside the piston rod of the jib hoisting cylinder 7R, and is outside in front of the piston. The piston of the jib hoisting cylinder 7L, which is collected in an oil tank (not shown) on the work machine side via the pipe line S1 'and the input / output port P1, and whose volume is reduced by the protrusion of the piston rod The hydraulic oil in the rod-side oil chamber 7Lp extends through the piston rod of the jib hoisting cylinder 7L in the axial direction and exits to the outside in front of the piston via the pipeline S1 and the input / output port P1. Are collected in an oil tank (not shown).

In this way, the jib component 3 of the base jib 2 with respect to the boom is guided by the rigging device 107 guided via the upper side (point T1 in FIG. 9) above the pivot positions 2a, 2a (position T2 in FIG. 9). The left and right jib hoisting cylinders 7L, one end of which is attached to the center of the jib component 3 adjacent to the base jib 2 and the other end of which is attached to the base jib 2 via the equalizer link 9 in a state where the movement is constrained. , 7R is activated, the jib component 3 adjacent to the base jib 2 protrudes from the base jib 2, and the jib body 5 extends between the jib component 3 and the base jib 2 with the rigging 107 fixed thereto. The expanded state of FIG. 2 changes from the contracted state as shown in FIGS. 1 and 2 to the extended state as shown in FIG.
At this time, the pulling position (position T1 in FIG. 9) of the rigging 107 on the top surface of the tip of the boom 102 is located above the pivot positions 2a and 2a (position T2 in FIG. 9) of the base jib 2 at the tip of the boom. In addition, the position of the rigging attachment portions 6 and 6 (position T3 in FIG. 9) in the jib component 3 to which the rigging element 107 is fixed, and the drawing position of the rigging element 107 on the top surface of the tip of the boom 102 (FIG. 9). Since the distance between the middle position T1) is held constant by the rigging element 107, the jib body 5 extends between the jib component 3 and the base jib 2 to which the rigging element 107 is fixed, The jib body 5 pivotally attached to the tip of the boom swings in the vertical plane around the pivot attachment positions 2a and 2a (position T2 in FIG. 9) of the base jib 2 at the tip of the boom 102 by the tension of the rigging 107. Shi It will be swung towards the end of the boom 102.

The two jib hoisting cylinders 7L and 7R are installed on the left and right sides of the jib body 5 so that when the jib component 3 adjacent to the base jib 2 is projected from the base jib 2, the jib is placed inside the base jib 2. As in the case where the undulating cylinder is disposed, the jib component 3 adjacent to the base jib 2 can be pushed out without causing any deviation in any direction with respect to the central axis Lx2 of the jib body 5. Therefore, a bending moment for bending the jib body 5 is not generated, and the jib body 5 is not bent due to the stress acting on the jib body 5. Therefore, the lifting load applied to the tip of the jib body 5 as the tip of the jib body 5 moves from the jib neutral axis to the top, bottom, left or right (radial direction about the jib neutral axis) due to the curvature of the jib body 5. The inconvenience that the jib body 5 is damaged due to the eccentricity of the jib body 5 and the jib body 5 is damaged, and the jib component 3 adjacent to the base jib 2 and the base jib by the force acting on one side of the jib body 5 The occurrence of inconvenience such as galling in the sliding portion between the two and the bending of the jib body 5 becomes resistance and the undulation capability of the jib body 5 is prevented from occurring.
In addition, the jib hoisting cylinders 7L and 7R are arranged on the left and right sides of the base jib 2 that forms the base of the jib body 5 having a telescopic structure in which the base jib 2 and a plurality of jib components 3, 4 and 4 ′ are connected to be extendable. Therefore, a sufficient space is secured inside the jib body 5 and various types of jib expansion / contraction mechanisms including a multi-stage jib expansion / contraction cylinder and a wire rope type expansion / contraction mechanism can be arranged inside the jib body 5. The jib components 3, 4, 4 ′ closer to the tip than the base jib 2, that is, the jib components 3, 4, 4 ′ fitted into the base jib 2 interfere with the jib hoisting cylinders 7L, 7R. Therefore, it is possible to easily realize a multi-stage jib body 5 and an increase in the expansion / contraction stroke, particularly as disclosed in JP2013-43706A. In addition to the jib component 4 (corresponding to the jib component 105 in FIG. 9), which is difficult with the known technique in FIG. It became so.
The jib hoisting cylinders 7L and 7R are configured to use two jib hoisting cylinders, but the installation locations are on the left and right sides of the base jib 2, so the jib body 5 as a whole distributes the weight of the front heavy. There is no adverse effect on the strength of the jib body 5 and the boom 102 when the jib body 5 is extended and the lifting performance (strength range performance) of the jib body 5 when the jib body 5 is extended. Since the installation locations of the jib hoisting cylinders 7L and 7R are on the left and right sides of the base jib 2, interference between the auxiliary winding wire rope or hook and the jib hoisting cylinders 7L and 7R can be prevented.
Since the bending load acting on the jib body 5 is supported by the base jib 2 configured independently of the jib hoisting cylinders 7L and 7R and the jib component 3 adjacent to the base jib 2, a lateral load is applied to the jib hoisting cylinders 7L and 7R. Also, problems such as oil leakage and damage to the jib hoisting cylinders 7L and 7R due to deformation of the oil seal and the like due to the action of bending load are prevented, and a difference in elongation occurs between the left and right jib hoisting cylinders 7L and 7R. The tilt of the jib body 5 to the left and right is also eliminated.

  However, even if the specifications of the left and right jib hoisting cylinders 7L and 7R are the same, there are differences in the dimensions of the respective parts of the left and right jib hoisting cylinders 7L and 7R within the allowable tolerances, the difference in piston fitting strength, etc. When the hoisting cylinders 7L and 7R protrude, left and right deviations occur in the protruding amounts of the pistons of the respective jib hoisting cylinders 7L and 7R, and left and right deviations occur in the pressing load acting on the left and right jib hoisting cylinders 7L and 7R. There is a case.

  Here, if the offset amount of the cylinder mounting portions 10L and 10R with respect to the central portion Q common to the rotation center of the equalizer link 9, that is, the value of Δx in FIG. When the protrusions of the left and right jib hoisting cylinders 7L and 7R cannot be synchronized during swinging and expansion / contraction, for example, the total length of the jib hoisting cylinder 7L is relatively long and the total length of the other jib hoisting cylinder 7R is relatively short. In this case, an equalizer link 9 attached to the base jib 2 at a position along the central axis Lx2 of the jib body 5 with the other ends of the left and right jib hoisting cylinders 7L and 7R pivoted, The center part Q is the center of rotation, and the cylinder mounting part 10L pivotally attached to the jib hoisting cylinder 7L on the side where the overall length is relatively long is the tip of the base jib 2 The cylinder mounting portion 10R which pivotally attaches the jib hoisting cylinder 7R on the side of which the overall length is relatively short is separated from the base portion of the base jib 2 and approaches the tip end of the base jib 2 By rotating in the direction, that is, by rotating counterclockwise from the neutral position as shown in FIG. 6 (a), the dimensional difference between the left and right jib undulation cylinders 7L and 7R is absorbed. The pressing load acting on the jib hoisting cylinders 7L and 7R is smoothed. On the contrary, when the overall length of the jib hoisting cylinder 7R is relatively long and the overall length of the other jib hoisting cylinder 7L is relatively short, the equalizer link 9 is The cylinder mounting portion 10R pivotally attached to the jib hoisting cylinder 7R on the side where the overall length is relatively long with Q being the rotation center moves away from the tip of the base jib 2 and approaches the base portion of the base jib 2, and the overall length is relatively The cylinder mounting part 10L pivotally attached to the shortened jib hoisting cylinder 7L rotates away from the base part of the base jib 2 and approaches the tip of the base jib 2, that is, as shown in FIG. By rotating in a clockwise direction from such a neutral position, the dimensional difference between the left and right jib hoisting cylinders 7L and 7R is absorbed and acts on the left and right jib hoisting cylinders 7L and 7R. Pressure load and would be smoothed.

In this situation, the pressure load acting on the left and right jib hoisting cylinders 7L and 7R is smoothed because the left and right jib hoisting cylinders 7L are respectively located at two positions symmetrical with respect to the center line Lx1 of the equalizer link 9. , 7R is provided with cylinder mounting portions 10L, 10R pivotally attached to the other end, and this equalizer link 9 is disposed horizontally along the central axis Lx2 of the jib body 5 so that the right jib hoisting cylinder 7R is attached to the shaft. The length M _R (moment arm length) of the perpendicular line extending from the line of action of the force F _R toward the central portion Q that is the rotation center of the equalizer link 9 and the axis of the left jib undulation cylinder 7L along the force F _L which is the center of rotation of the equalizer link 9 from the working line center of outstretched perpendicular foot toward the Q length M _{L (the} length of the moment arm) is shown in FIG. 6 (a) This is because being equal manner in the neutral state such equalizer link 9. That is, under the condition that the value of the offset amount Δx is 0, in short, the cylinder mounting portion 10L and the cylinder mounting portion 10R are arranged in a straight line with the center portion Q that is the rotation center of the equalizer link 9 in the opposite direction. in the arrangement which is located at a distance, always M _{R =} M _L becomes regardless of the change in the attitude of the equalizer link 9, the equalizer link 9 of the arm length M _R and the moment arm of moment length M ratio of _L does not function as a booster to change the, necessarily, is the is the F _L corresponding to its reaction force F _R is equal.
More specifically, FIG. 6 the rotation angle of the equalizer 9 from the neutral position of the equalizer link 9 as shown in (a) theta, the distance from the center Q to the cylinder attachment portion 10R M _R max, center if the distance from the section Q to the cylinder attachment portions 10L and _{M L max, M R = M} R max · cosθ, a _{M L = M L max · cosθ} , _{moreover, &shy;&shy; M} R max = M _L max is a from _M R = _{M L} next is that consisting of the clockwise rotation moment _F R · _{M R} and counterclockwise from the balance condition of the rotating moment _F L · _{M L} to _F R = _{F L.}

  Therefore, even when a situation occurs in which the protruding amounts of the left and right jib hoisting cylinders 7L and 7R cannot be synchronized when the jib body 5 is swung out and extended, the pressure load acting on the left and right jib hoisting cylinders 7L and 7R is not affected. There is no imbalance, and the bending of the jib body 5 in the left-right direction due to the damage of the jib undulation cylinders 7L, 7R due to an excessive load acting on one side and the variation in the protruding amount of the left and right jib undulation cylinders 7L, 7R is obviated. Can be prevented.

Even when an external force that swings the tip of the jib body 5 to the left or right due to the tilt of the chassis or the like is applied during the lifting work using the swinging jib body 5, the force is F _R = F _L. Since the left and right jib hoisting cylinders 7L and 7R are evenly distributed, even when an external force that swings the tip of the jib body 5 to the left and right acts during the lifting work using the swinging jib body 5 A large imbalance does not occur in the pressing load acting on the jib hoisting cylinders 7L and 7R, and damage to the jib hoisting cylinders 7L and 7R due to an excessive load is prevented in advance.

  As described above, the case where the value of the offset amount Δx is 0 has been described in the paragraphs 0060 to 0063. In practice, however, in this embodiment, the cylinder mounting portion with respect to the center portion Q that is common with the rotation center of the equalizer link 9 is used. The values of the offset amounts Δx of 10L and 10R are not 0 but positive values as shown in FIG.

Accordingly, when a situation occurs in which the protruding amounts of the left and right jib hoisting cylinders 7L and 7R cannot be synchronized when the jib body 5 is swung out and extended, for example, the overall length of the jib hoisting cylinder 7L becomes relatively long and the other jib hoisting cylinder 7L The cylinder 7R has a relatively short overall length, and the equalizer link 9 has a cylinder mounting portion 10L pivotally attached to the jib hoisting cylinder 7L on the side where the overall length is relatively long with the center portion Q as the rotation center. A cylinder mounting portion 10R, which is spaced from the tip of the base jib 2 and approaches the base portion of the base jib 2 and is pivotally attached to the jib hoisting cylinder 7R on the side where the overall length is relatively short, is separated from the base portion of the base jib 2 and A direction approaching the tip, that is, as shown in FIG. 6B after rotating counterclockwise from the neutral position as shown in FIG. When the posture is changed to the state, the cylinder mounting portion 10L moved away from the tip of the base jib 2 and moved in the direction approaching the base portion of the base jib 2 is inside, that is, the central axis Lx2 of the jib body 5 (FIGS. 6A and 6). The cylinder mounting portion 10R moved in a direction approaching the tip of the base jib 2 and moved away from the base portion of the base jib 2 is outside, that is, the central axis Lx2 of the jib body 5 (In FIG. 6A and FIG. 6B, Lx1 is also the same).
The reason for this is that under such an offset condition, each of the two cylinder mounting portions 10L and 10R has a locus of a circle passing through each of the two cylinder mounting portions 10L and 10R around the center portion Q of the equalizer link 9. Of these, the center portion Q of the equalizer link 9, that is, moves only along the arc locus PL, PR of the portion closer to the base portion of the base jib 2 than the center of rotation, and in this section of the arc locus PL, PR, the cylinder mounting portion 10L is moved to the base jib. 2 is closer to the center axis Lx2 of the jib main body 5 as it is closer to the base side of the jib body 2, and is further away from the central axis Lx2 of the jib body 5 as the cylinder mounting portion 7R is closer to the tip side of the base jib 2. .
Thus, the overall length is relatively long since the side of the jib hoist from the action line of the force F _L along the axis of the cylinder 7L of the center vertical line extended toward the Q is the rotation center of the equalizer link 9 foot length M _L '(length of the moment arm) is toward the center Q from the action line of the force F _R along the jib derricking cylinder 7R axis of the full length becomes relatively short side as the rotational axis of the equalizer link It becomes shorter than the length M _R ′ (length of moment arm) of the leg of the extended perpendicular.
Here, the left and right of the jib derricking cylinder 7L, size F _L of the pressing force acting along the axis of _7R, since F _R are basically equal, the rotational force acting on the equalizer link 9, the overall length relative to compared to the rotational force applied from the cylinder attachment portion 10L of the lengthened side connected to the side of the jib derricking cylinder 7L F _L · M _L '(short rotational force applied through the moment arm of), this Rotating force F _R · M _R ′ (given through the arm of the longer moment) applied from the cylinder mounting portion 10R on the side where the jib hoisting cylinder 7R on the side whose overall length is relatively short in the direction opposite to Rotational force) is greater.
Therefore, the equalizer link 9 has a cylinder mounting portion 10R pivotally attached to the jib hoisting cylinder 7R on the side where the overall length is relatively shortened and is spaced apart from the tip of the base jib 2 and approaches the base portion of the base jib 2, and the overall length is relatively The cylinder mounting portion 10L pivotally attached to the longer jib hoisting cylinder 7L is away from the base portion of the base jib 2 and approaches the tip of the base jib 2, that is, as shown in FIG. 6B. 6 to rotate in the clockwise direction to return the posture to the neutral position as shown in FIG. 6 (a). The rotation of the equalizer link 9 causes the overall length to be relatively short. A correction is made so that the jib hoisting cylinder 7L on the side where the overall length of the jib hoisting cylinder 7R is extended and the length of the jib hoisting cylinder 7L is reduced is reduced. Tuning displacement of the protrusion amount is to be automatically eliminated.

On the contrary, the overall length of the jib hoisting cylinder 7R is relatively long and the overall length of the other jib hoisting cylinder 7L is relatively short, so that the equalizer link 9 has its central portion Q as the center of rotation. The cylinder mounting portion 10R pivotally attached to the jib hoisting cylinder 7R on the side where the overall length is relatively long is separated from the tip of the base jib 2 and approaches the base portion of the base jib 2, and the overall length is relatively short. The direction in which the cylinder mounting portion 10L pivotally attached to the jib hoisting cylinder 7L moves away from the base portion of the base jib 2 and approaches the tip of the base jib 2, that is, the clockwise direction from the neutral position as shown in FIG. The cylinder mounting portion 10R moved away from the tip of the base jib 2 and moved in the direction of approaching the base of the base jib 2, the inner side, that is, the jib body. The cylinder mounting portion 10L moved in a direction approaching the center axis Lx2 of the cylinder and separated from the base of the base jib 2 and moved in a direction of approaching the tip of the base jib 2 is moved outward, that is, in a direction away from the center axis Lx2 of the jib body 5. Will move.
Thus, the overall length is relatively long since the side of the jib hoist from the action line of the force F _R along the axis of the cylinder 7R in the center vertical line extended toward the Q is the rotation center of the equalizer link 9 foot length M _R '(the length of the moment arm) is toward the center Q from the action line of the force F _L along the axis of the jib derricking cylinder 7L full-length becomes relatively short side as the rotational axis of the equalizer link It becomes shorter than the length M _L ′ (length of the arm of the moment) of the leg of the extended perpendicular.
Left and right jib derricking cylinder 7L, size F _L of the pressing force acting along the axis of _7R, since F _R are basically equal, the rotational force acting on the equalizer link 9, the overall length is relatively long Compared to the rotational force F _R · M _R ′ (rotational force applied through the arm of the shorter moment) applied from the cylinder mounting portion 10R on the side where the jib undulating cylinder 7R on the connected side is connected rotational force applied through the arm rotational force F _L · M _L '(longer moments full length in the direction is given from the cylinder attachment portion 10L relatively connecting the shortened side of the jib derricking cylinder 7L side ) Is larger.
Therefore, the equalizer link 9 has a cylinder mounting portion 10L pivotally attached to the jib hoisting cylinder 7L on the side whose overall length is relatively shortened, and is separated from the tip of the base jib 2 and approaches the base portion of the base jib 2, and the overall length is relatively The cylinder mounting portion 10R pivotally attached to the jib hoisting cylinder 7R on the longer side is spaced away from the base portion of the base jib 2 and rotates in the direction approaching the tip of the base jib 2, that is, counterclockwise. As a result of the rotation of 9, the jib hoisting cylinder 7 </ b> L on the side whose overall length is relatively shortened is extended, and the jib hoisting cylinder 7 </ b> R on the side whose overall length is relatively long is reduced. The synchronization deviation of the protrusion amounts of 7L and 7R is automatically eliminated.

In this embodiment, in particular, as shown in FIGS. 4 and 7, a jib which is an oil chamber on the side to which hydraulic oil is supplied when the jib component 3 adjacent to the base jib 2 protrudes from the base jib 2. The anti-piston rod side oil chamber 7Rr of the hoisting cylinder 7R and the anti-piston rod side oil chamber 7Lr of the jib hoisting cylinder 7L are connected to each other by a connecting pipe S3 and act along the axes of the left and right jib hoisting cylinders 7L, 7R. pressing forces F _L, because so as to reliably equalize the magnitude of F _R, the total length becomes relatively short since the side of the jib derricking cylinder 7L, the overall length by extending the 7R relatively long Correction for reducing the jib undulation cylinders 7R, 7L on the other side is performed with higher accuracy, and the synchronization deviation of the protrusion amounts of the left and right jib undulation cylinders 7L, 7R can be eliminated at a high level. That. (The values of M _R ′ and M _L ′ related to the posture change of the equalizer link 9 are eliminated by eliminating the error between F _R and F _L from the variables related to F _R · M _R ′ and F _L · M _L ′. Will only affect F _R · M _R ', F _L · M _L '.)

Here, as an example, the structure in which the equalizer link 9 is attached to the base jib 2 is described. However, contrary to this embodiment, the other ends of the jib hoisting cylinders 7L and 7R are attached to the left and right of the base jib 2 and the base jib is attached. 2, the equalizer link 9 is rotatably attached to the central upper surface of the jib component 3 adjacent to 2 or the central portion of the lower surface of the central portion (position along the central axis Lx <b> 2 of the jib main body 5), and the cylinder mounting portion 10 </ b> L of the equalizer link 9 is mounted. , 10R, one end of the jib hoisting cylinders 7L, 7R may be pivotally attached.
The equalizer link 9 is attached to the upper surface or lower surface of the central portion of the jib component 3 adjacent to the base jib 2 because the equalizer link 9 is centered in the thickness direction of the base jib 2 (up and down direction when the jib is laid down). This is because interference occurs between the jib components 4, 4 ′ fitted in the jib component 3 and the equalizer link 9 if installed in the interior part.
However, when such a configuration is applied, it is necessary to employ an equalizer link 9 in which the two cylinder mounting portions 10L and 10R are offset toward the tip end side of the jib body 5 with respect to the center portion Q. Also in this case, the operation and effect provided by the equalizer link 9 are the same as described above.
When the configuration in which the equalizer link 9 is attached to the upper surface or the lower surface of the tip portion of the jib component 3 is applied, the overall length of the jib undulation cylinder 7R is relatively long and the overall length of the other jib undulation cylinder 7L is relative. The cylinder mounting portion 10R pivotally attached to the jib hoisting cylinder 7R on the side having a relatively long overall length is spaced apart from the base portions 2a, 2a of the base jib 2 so as to be inside, that is, the central axis Lx2 of the jib body 5 The cylinder mounting portion 10L, which is pivotally attached to the jib hoisting cylinder 7L on the side of which the overall length is relatively shortened while moving in the direction approaching the base, approaches the bases 2a, 2a of the base jib 2 and is outside, that is, the central axis of the jib body 5 moves in a direction away from Lx2 and _{M L} '> _{M R',} in _short, becomes _{F L · M L '> F} R · M R', on the side where the total length becomes relatively short di Derricking cylinder 7L full length as well as extension jib derricking cylinder 7R relatively becomes long side the EQ link 9 in the direction of reducing made to correct the tuning shift amount of projection of the rotating cylinder.
On the contrary, when the overall length of the jib hoisting cylinder 7L is relatively long and the overall length of the other jib hoisting cylinder 7R is relatively short, the side where the overall length is relatively long The cylinder mounting portion 10L pivotally attached to the jib hoisting cylinder 7L moves away from the base portions 2a, 2a of the base jib 2 and moves inward, that is, in a direction approaching the central axis Lx2 of the jib body 5, and the overall length is relatively shortened. The cylinder mounting portion 10R pivotally attached to the side jib hoisting cylinder 7R approaches the bases 2a, 2a of the base jib 2 and moves in the direction away from the center axis Lx2 of the jib main body 5 so that M _R '> M _L ' in short, it becomes _{F R · M R '> F} L · M L', the side of the jib hoist the entire length becomes relatively long along with the total length jib derricking cylinder 7R relatively shortened side is extended Siri Rotates and equalizer link 9 in a direction Da 7L is reduced will be made to correct the tuning shift amount of projection of the cylinder.

  In this embodiment, the fuse valve 21R is installed at the connecting portion between the pipe line passing through the piston rod of the jib hoisting cylinder 7R and the connecting pipe line S3, and passes through the piston rod of the jib hoisting cylinder 7L. Since the fuse valve 21L is installed at the connection between the pipe line and the connecting pipe line S3, even if the connecting pipe line S3 is damaged during the operation, the oil on the anti-piston rod side of the jib hoisting cylinder 7R The posture of the jib body 5 can be maintained by preventing leakage of hydraulic oil from the chamber 7Rr and leakage of hydraulic oil from the anti-piston rod side oil chamber 7Lr of the jib hoisting cylinder 7L.

  FIG. 8 is a hydraulic circuit diagram showing an outline of the hydraulic circuit 22 in the jib hoisting device for a working machine according to another embodiment to which the present invention is applied.

In this embodiment, since the flow divider that functions as a tuning device for synchronizing the protruding amounts of the jib hoisting cylinders 7L and 7R arranged on the left and right of the base jib 2 is mounted on the hydraulic circuit, FIG. It is not always necessary to attach the equalizer link 9 as shown in FIGS. 3 and 6A, 6B.
Therefore, in this embodiment, the attachment of the equalizer link 9 is omitted, and the piston rod side of the jib hoisting cylinders 7L and 7R is attached to the left and right side surfaces of the jib component 3 adjacent to the base jib 2 and the base jib is attached. Brackets equivalent to brackets 8L and 8R are provided on the left and right side surfaces of 2 and the tube side of jib hoisting cylinders 7L and 7R is attached as the other end, or the tube side of jib hoisting cylinders 7L and 7R is used as one end. Attached to the left and right side surfaces of the jib component 3 adjacent to 2 and provided with brackets equivalent to the brackets 8L and 8R on the left and right side surfaces of the base jib 2, and attached the piston rod side of the jib hoisting cylinders 7L and 7R as the other end (Not shown).

  In FIG. 8, P1 and P2 are input / output ports of the hydraulic circuit 22, which are connected to two input / output ports of a three-way switching valve (not shown) (hereinafter simply referred to as a three-way switching valve) installed on the work machine side. Has been. Moreover, the code | symbol T in FIG. 8 represents the oil tank by the side of a working machine.

  A pipe S1 connected to the input / output port P1 is connected to the piston rod side oil chamber 7Lp of the jib hoisting cylinder 7L via a pipe extending in the axial direction inside the piston rod of the jib hoisting cylinder 7L and exiting outside in front of the piston. The pipe S1 ′ branched from the pipe S1 is connected to the piston rod of the jib hoisting cylinder 7R via a pipe extending in the axial direction inside the piston rod of the jib hoisting cylinder 7R and exiting outward before the piston. It is connected to the side oil chamber 7Rp. This is the same as the embodiment shown in FIG.

On the other hand, the input / output port P2 includes two hydraulic motors that operate completely synchronously under mechanical connection, and the hydraulic oil supplied from the input / output port P2 is equally divided into two and output. A divider 23 is connected.
In this embodiment, the flow divider 23 functions as a tuning device for synchronizing the protruding amounts of the jib undulating cylinders 7L and 7R.

  A pipe line S2 connected to one input / output port of the flow divider 23 includes a pipe line passing through the pipe line S4 in the block valve 24, the counter balance valve 20R of the hoisting cylinder 7R and the piston rod of the jib hoisting cylinder 7R in the axial direction. The pipe S2 'connected to the anti-piston rod side oil chamber 7Rr of the jib hoisting cylinder 7R via the other and the other input / output port of the flow divider 23 is connected to the pipe S4' in the block valve 24 and the hoisting cylinder. The counter balance valve 20L of 7L and the piston rod of the jib hoisting cylinder 7L are connected to the anti-piston rod side oil chamber 7Lr of the jib hoisting cylinder 7L through a pipe passing through in the axial direction.

When the jib hoisting cylinders 7L and 7R are extended, the block valve 24 is damaged due to an abnormal pressure increase in the jib hoisting cylinder on the side where the stroke end is first reached and the pipe line related to the jib hoisting cylinder. This is to prevent this.
As a result of the flow divider 23 equally dividing the hydraulic oil supplied from the input / output port P2 and outputting it, for example, when the jib hoisting cylinder 7R reaches the stroke end at the time of extension before the jib hoisting cylinder 7L. In this case, the anti-piston rod side oil chamber 7Rr is passed through the pipe line S2, the pipe line S4 and the counter balance valve 20R while the volume of the anti-piston rod side oil chamber 7Rr of the jib hoisting cylinder 7R is constrained in the maximum state. However, in this case, the relief valve is caused by an excessive pressure increase in the pipeline S4 transmitted to the relief valve 25 in the block valve 24 via the check valve 24R1 in the block valve 24. 25 is operated, and excess hydraulic oil is returned to the tank T via the line S5, whereby the jib hoisting cylinder 7R, the line S2, the line S4, etc. are damaged. The to prevent. At this time, the flow of hydraulic oil from the high pressure side pipe line S4 to the low pressure side pipe line S4 ′ is prevented by the check valves 24L1 and 24R2 in the block valve 24. There is no effect on the 7L expansion operation.
On the other hand, when the jib hoisting cylinder 7L reaches the stroke end at the time of extension before the jib hoisting cylinder 7R, the volume of the anti-piston rod side oil chamber 7Lr of the jib hoisting cylinder 7L becomes smaller. The hydraulic oil is supplied to the anti-piston rod side oil chamber 7Lr through the pipelines S2 ′, S4 ′, and the counter balance valve 20L while being constrained in the maximum state. The relief valve 25 is actuated by an excessive pressure rise in the pipe line S4 ′ transmitted to the relief valve 25 in the block valve 24 via the check valve 24L1 in the valve 24, and excess hydraulic oil is discharged through the pipe line S5. By returning to the tank T, damage to the jib hoisting cylinder 7L, the pipeline S2 ', the pipeline S4', and the like is prevented. At this time, the flow of hydraulic oil from the high pressure side pipe line S4 ′ to the low pressure side pipe line S4 is prevented by the check valves 24R1 and 24L2 in the block valve 24. There is no effect on the 7R expansion operation.
The functions of the counter balance valves 20L and 20R are the same as those in the embodiment shown in FIG.

In this embodiment, the jib hoisting cylinders 7L and 7R each project when the jib hoisting cylinders 7L and 7R project by the function of the flow divider 23 itself that equally divides the hydraulic oil supplied from the input / output port P2 into two parts. Since the occurrence of deviations in the protruding amounts of the 7L and 7R pistons is prevented, it is possible to prevent the deviation of the protruding amounts of the left and right jib hoisting cylinders 7L and 7R from being out of synchronization.
Accordingly, a bending moment for bending the jib body 5 is not generated, and the jib body 5 is not bent due to the stress acting on the jib body 5. The tip moves from the jib neutral axis up / down / left / right (radial direction around the jib neutral axis), and the lifting load applied to the tip of the jib body 5 is decentered, resulting in excessive stress acting on the jib body 5. This causes inconvenience that the jib body 5 is damaged, and that the force acting on one side of the jib body 5 causes inconvenience in the sliding portion between the jib component 3 adjacent to the base jib 2 and the base jib 2. Further, it is possible to prevent a problem that the bending of the jib body 5 becomes resistance and the undulation capability of the jib body 5 is lowered.
Further, a sufficient space is secured inside the jib body 5 and various types of jib expansion / contraction mechanisms such as a multistage jib expansion / contraction cylinder and a wire rope type expansion / contraction mechanism can be arranged inside the jib body 5. This makes it possible to easily realize the multi-stage jib body 5 and the extension of the expansion / contraction stroke, and the jib body 5 becomes a weight distribution of the front heavy as a whole or excessive weight increase occurs. The problem of lowering the strength of the jib body 5 and the boom 102 when the armor is extended and the deterioration of the lifting performance (strength region performance) of the jib body 5 are improved. The installation location of the jib hoisting cylinders 7L and 7R is the base jib 2 Since it is on both the left and right sides, interference between the auxiliary winding wire rope and hook and the jib hoisting cylinders 7L and 7R is prevented, and the bending load acting on the jib body 5 is Problems such as oil leakage and damage to the jib hoisting cylinders 7L and 7R due to deformation of the oil seal and the like because the lateral load and bending load are not applied to the jib hoisting cylinders 7L and 7R supported by the jib 2 and the jib component 3 The same effect as that of the first embodiment is also obtained in that the right and left tilt of the jib body 5 due to the difference in expansion between the left and right jib hoisting cylinders 7L and 7R is eliminated.
Further, when such a configuration is applied, when a lateral bending occurs in the jib main body 5 due to a lateral load or the like, a large load acts on the jib undulation cylinder 7L or 7R inside the bending direction. However, if the cylinder jib hoisting cylinders 7L and 7R capable of withstanding this load are mounted, the bending can be pushed back, and the lateral bending of the jib body 5 can be reduced. Since the amount of lateral movement of the suspended load is reduced by reducing the lateral bending, there is an advantage that the stress acting around the central axis Lx2 of the jib body 5 can be reduced.

  Furthermore, in this embodiment, in addition to the flow divider 23, the configuration of the equalizer link 9 as shown in FIGS. 1 to 3 and FIGS. 6A and 6B may be used in combination.

  In the case where the equalizer link 9 is also provided, even if an external force that swings the tip of the jib body 5 to the left or right due to the tilt of the chassis or the like is applied during the lifting work using the swinging jib body 5 Since the force is evenly distributed to the left and right jib hoisting cylinders 7L and 7R through the equalizer link 9, an external force that swings the tip of the jib main body 5 to the left and right acts during the hanging work using the swinging jib main body 5 Even in this case, a large imbalance does not occur in the pressing load acting on the left and right jib undulation cylinders 7L and 7R, and damage to the jib undulation cylinders 7L and 7R due to an excessive load can be prevented.

  That is, in the configuration in which the equalizer link 9 is provided, the flow divider 23 synchronizes the protruding amounts of the left and right jib hoisting cylinders 7L and 7R, and at the same time, the equalizer link 9 allows the left and right jib hoisting cylinders 7L and 7R to be synchronized. The applied pressing load is synchronized.

  A part or all of the embodiment disclosed above can be appropriately expressed by the description shown in the following supplementary notes, but the form for carrying out the invention and the technical idea of the invention are not limited to these. Absent.

[Appendix 1]
A jib body (5) in which a plurality of jib components (2, 3, 4, 4 ′) including a base jib (2) pivotally attached to the tip of a boom (102) are telescopically connected by a telescopic structure; A jib hoisting cylinder (7L, 7R) for expanding and contracting the jib component (3) adjacent to the base jib (2) with respect to the base jib (2), and pulled out from the top surface of the tip of the boom (102) By extending the overall length of the jib (5) by operating the jib hoisting cylinder (7L, 7R) with the rigging (107) fixed to the adjacent jib component (3) and restraining its movement A jib hoisting device for a working machine that swings out the jib (5) using the tension of the rigging (107),
The jib hoisting cylinders (7L, 7R) are arranged on the left and right sides of the base jib (2) and one end thereof is attached to the adjacent jib component (3) while the other end is attached to the base jib (2). A jib hoisting device for a working machine (see FIGS. 1 to 4 and 9).

[Appendix 1 ']
A plurality of jib components (2, 3, 4, 4) including a base jib (2) pivotally attached to the tip of the boom (102) of the work machine (101) so as to be swingable in a vertical plane. 4 ') are telescopically connected to each other so as to expand and contract, and the jib hoisting cylinders (7L, 7R) that extend and retract the jib component (3) adjacent to the base jib (2) relative to the base jib (2). ), And the adjacent jib component (3) is drawn from the upper surface of the tip of the boom (102) and passes above the pivot position (2a, 2a) of the base jib (2). A rigging attachment portion (6) for fixing a fixed-length rigging (107) guided to the jib component (3) is provided, and when the jib (5) is swung out, the rigging (107 ) The tip of the rigging attachment (6) The jib hoisting cylinder (7L, 7R) is extended in a state where the movement of the jib component (3) is restrained by the length of the rigging (107), and the adjacent jib component (3 ) Protrudes from the base jib (2) to extend the entire length of the jib (5), and the jib (5) is swung out to the tip of the boom (102) using the tension of the rigging (107). A jib hoisting device for a work machine,
The jib hoisting cylinders (7L, 7R) are arranged on the left and right sides of the base jib (2) and one end thereof is attached to the adjacent jib component (3) while the other end is attached to the base jib (2). A jib hoisting device for a working machine (see FIGS. 1 to 4 and 9).

[Appendix 2]
The jib hoisting device according to appendix 1, 1 ′, comprising a tuning device (9 or 23) for synchronizing the operating state of the jib hoisting cylinders (7L, 7R) arranged on the left and right of the base jib (2). (See FIG. 1 to FIG. 4, FIG. 6 or FIG. 8).

[Appendix 3]
The tuning device is constituted by an equalizer link;
The jib hoisting device (not shown) according to appendix 2, wherein one end of each jib hoisting cylinder is attached to the adjacent jib component via the equalizer link.

[Appendix 4]
The tuning device is constituted by an equalizer link (9);
The jib hoisting device according to appendix 2, wherein the other end of each jib hoisting cylinder (7L, 7R) is attached to the base jib (2) via the equalizer link (9) (FIG. 1 to FIG. 1). 4, see FIG.

[Appendix 5]
The equalizer link is an equalizer link provided with a cylinder mounting portion at each of two positions symmetrical with respect to the center line thereof,
A central portion of the equalizer link is pivotally mounted on the adjacent jib component along the central axis of the jib body so as to be rotatable in a horizontal plane.
The jib hoisting device (not shown) according to appendix 3, wherein one end of each jib hoisting cylinder is attached to the adjacent jib component via the equalizer link.

[Appendix 6]
The equalizer link (9) is an equalizer link (9) provided with a cylinder mounting portion (10L, 10R) at each of two positions symmetrical with respect to the center line (Lx1),
The center portion of the equalizer link (9) is pivotally mounted on the base jib (2) along the center axis (Lx2) of the jib body (5) in a rotatable manner in a horizontal plane,
The jib hoisting device according to appendix 4, wherein the other end of each jib hoisting cylinder (7L, 7R) is attached to the base jib (2) via the equalizer link (9) (FIG. 1 to FIG. 1). 4, see FIG.

[Appendix 7]
Each of the cylinder mounting portions (10L, 10R) extends from the central portion (Q) of the equalizer link (9) along the central axis (Lx2) of the jib main body (5). , 7R) and the jib hoisting device according to appendix 5 or appendix 6 (refer to FIGS. 1 to 4 and 6), wherein the device is arranged with an offset (Δx) in a direction away from it.

[Appendix 8]
In the two jib hoisting cylinders (7L, 7R), oil chambers (7Lr, 7Rr) to which hydraulic oil is supplied when the adjacent jib components (3) project from the base jib (2) are connected. 8. The jib undulation device according to any one of appendix 7 characterized by being connected to each other by a pipe line (S3) (see FIGS. 1 to 4 and FIGS. 6 to 7).

[Appendix 9]
Fuse valves (21L, 21), which prevent leakage of hydraulic oil from the oil chambers (7Lr, 7Rr) are respectively connected to the connecting pipes (S3) and the oil chambers (7Lr, 7Rr). 21R) is installed, the jib hoisting device according to appendix 8 (see FIGS. 1 to 4 and FIGS. 6 to 7).

[Appendix 10]
In each of the oil chambers (7Lr, 7Rr) to which hydraulic oil is supplied when the adjacent jib component (3) protrudes from the base jib (2), the adjacent jib component (3) is reduced. Supply hydraulic oil to the oil chamber (7Lr, 7Rr) on the side from which the adjacent jib component (3) protrudes by detecting the pressure rise of the hydraulic oil supplied to the oil chamber (7Lp, 7Rp) Supplementary notes 1, supplementary notes 1 ′, supplementary notes 2, supplementary notes 3, which are provided with counter balance valves (20L, 20R) that open the pipelines (S2, S2 ′) that allow the hydraulic oil to be discharged 4. Jib hoisting device according to any one of 4, appendix 5, appendix 6, appendix 7, appendix 8, and appendix 9 (see FIGS. 1 to 4 and FIGS. 6 to 7).

[Appendix 11]
The jib hoisting device according to appendix 2, wherein the tuning device is configured by a flow divider (23) that supplies hydraulic oil equally to the two jib hoisting cylinders (7L, 7R). 1 to 4 and 8).

[Appendix 12]
Furthermore, a supplementary flow divider (23) for supplying hydraulic oil equally to the two jib hoisting cylinders (7L, 7R) is provided, Supplementary note 3, Supplementary note 4, Supplementary note 5, Supplementary note 6 or Supplementary note 7 The jib raising / lowering apparatus as described in any one of these (refer FIGS. 1-4, FIG. 8).

  INDUSTRIAL APPLICABILITY The present invention can be generally applied to a jib for a working machine in which the jib is swung out to the tip of the boom by extending the entire length of the jib by extending the jib hoisting cylinder.

1 Jib 2 Base jib 2a Base 3 Jib component 4 adjacent to the base jib 4 Jib component 4 'Jib component 5 Jib body 6 Rig attachment 7L Jib hoisting cylinder (left side)
7Lp Piston rod side oil chamber 7Lr Anti-piston rod side oil chamber 7R Jib hoisting cylinder (right side)
7Rp Piston rod side oil chamber 7Rr Anti-piston rod side oil chamber 8L, 8R Bracket 9 Equalizer link (tuning device)
10L, 10R Cylinder mounting portion 11 Jib hoisting device 12L, 12R Supporters 13, 14, 15 Metal plate 16 Main body portion 16a Foot portion 17 Resin plate 18 Decoration frame 18a One side portion 19 Hydraulic circuit 20L, 20R Counter balance valves 21L, 21R Fuse valve 22 Hydraulic circuit 23 Flow divider (tuning device)
24 Block valve 24L1, 24L2 Check valve 24R1, 24R2 Check valve 25 Relief valve 100 Jib hoisting expansion / contraction device (conventional example)
101 Working machine 102 Boom 103 Base jib (conventional example)
104,105 jib components (conventional example)
106 Jib body 106 'Jib body swing position 107 Rigging tool Lx1 Equalizer link center line Lx2 Jib body center axis Q Equalizer link rotation center, center part P1, P2 Input / output ports S1, S1' Pipe lines S2, S2 ' line S3 connecting line S4, S4 'line S5 conduit T1 rigging pulled-out position T2 pivot position T3 rigging Besujibu fixing position _{F L} left jib hoist cylinder axis along the force _{F R} right Forces along the axis of the jib hoisting cylinder M _L , M _L 'The length of the perpendicular foot extending from the line of action of the force along the axis of the left jib hoisting cylinder toward the center of rotation of the equalizer link (the length of the arm of the moment) Sa)
M _R , M _R 'The length of the leg of the perpendicular line extending from the line of action of the force along the axis of the right jib undulation cylinder toward the center of rotation of the equalizer link (the length of the arm of the moment)
Δx Offset amount PL, PR Arc trajectory of the part of the circle path passing through each of the two cylinder mounting parts centering on the center part of the equalizer link and closer to the base part of the base jib than the center part of the equalizer link

Claims (3)

A jib main body in which a plurality of jib components including a base jib pivotally attached to the tip of the boom is telescopically connected, and one end is attached to the jib component adjacent to the base jib and the other end is connected to the base jib And a jib hoisting cylinder attached to the jib hoisting cylinder, and an extension operation of the jib hoisting cylinder extends the adjacent jib component from the base jib to swing out the jib body to the tip of the boom. Jib hoisting device,
The jib hoisting cylinder is arranged on the left and right of the base jib and one end thereof is attached to the adjacent jib component, while the other end is attached to the base jib .
A tuning device that synchronizes the operating state of the jib hoisting cylinders arranged on the left and right of the base jib;
The tuning device is constituted by an equalizer link;
One end or the other end of each jib hoisting cylinder is attached to the adjacent jib component or the base jib via the equalizer link,
The equalizer link is an equalizer link provided with a cylinder mounting portion at each of two positions that are symmetrical with respect to the center line thereof,
A center portion of the equalizer link is pivotally mounted on the adjacent jib component or the base jib so as to be rotatable in a horizontal plane along the central axis of the jib body.
One end or the other end of each jib hoisting cylinder is attached to the adjacent jib component or the base jib via the equalizer link,
Each of the cylinder mounting portions is arranged to be offset from the center portion of the equalizer link along the central axis of the jib body in a direction away from each jib hoisting cylinder. Jib undulation device of the machine. The oil chambers on the side where hydraulic oil is supplied when the adjacent jib components protrude from the base jib in the two jib hoisting cylinders are connected to each other by a connecting pipe. Item 1. The jib undulation device according to Item 1 . The jib hoisting device according to claim 1 or 2 , further comprising a flow divider for supplying hydraulic oil evenly to the two jib hoisting cylinders.

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