JP2007210715A - Telescopic boom - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a telescopic boom excellent in strength and easy in assembling and insertion of the boom although a steel sheet of thin thickness is used for light weight and a compact size. <P>SOLUTION: A plurality of distal end lower part slide pads 10 having a plane shape of a rectangular shape accomplishing a shape along an outer surface of a polygonal belly surface formed into a polygonal shape proximate to a semicircle are provided inside on a belly surface side near a distal end of respective inner side booms 3 individually fitted/inserted to an inner side on a belly surface side near distal end of respective outer side booms 2 of adjacent booms of the telescopic boom 1 and having ends in a width direction contacting with each other and fitted/inserted to the outer side booms 2. Thereby, it has a constitution for slidably supporting a corner part between the flat plate parts of the polygonal belly surface of the inner side boom 3 with a rigid structure. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an improvement of a telescopic boom mounted on an upper swing body such as a wheel crane so as to be able to move up and down, and more particularly to a telescopic boom in which a transverse cross-sectional shape is formed into a deformed cross-section, that is, a ventral side is bent into a polygonal shape. It is.

  The gap between the telescopic booms mounted on the upper swing body such as a wheel crane so as to be able to undulate must be made as small as possible in order to reduce weight and size. On the other hand, in order to extend and retract the telescopic boom, it is necessary to provide a sliding member (slide pad) on the inner surface side of the outer boom, and means for fixing the sliding member (slide pad) to the inner surface side of the outer boom (for example, , Stopper) is required. However, when such a stopper is provided on the inner surface of the outer boom, it interferes with a pad carrier (a pad positioning member on the base side of the boom base) provided on the outer surface of the inner boom when the boom is assembled and inserted. In this case, the gap between the booms is increased or the slide pad is thinned to prevent interference.

  However, in the former case, there is no choice but to sacrifice the weight and compactness of the telescopic boom, and in the latter case, there is a problem that abnormal wear or abnormal vibration of the slide pad occurs due to increased surface pressure. It has occurred. Examples of telescopic booms that can solve such problems include the following. Hereinafter, a telescopic boom according to a typical conventional example such as a wheel crane will be described with reference to the accompanying drawings.

  First, the telescopic boom according to Conventional Example 1 will be described with reference to FIG. 11 which is a plan sectional view of the sliding member device (corresponding to the tip lower slide pad). The telescopic boom according to this conventional example 1 relates to a sliding member device of an telescopic boom, and reduces the weight by shortening the boom length at the minimum shortening relative to the boom length at the maximum extension of the telescopic boom, An object of the present invention is to provide a sliding member device for an extendable boom that improves safety during traveling and does not cause deformation or cracking of the boom. More specifically, a U-shaped pad storage member having an open end is welded to the inner side of the distal end portion of an outer tab (hereinafter referred to as an outer boom) 52 to store the pad 62 and the shim 63. A gap m between the inner boom (hereinafter referred to as the inner boom) 53 and the pad 62 is adjusted by a shim 63. A cover 66 that prevents the pad 62 and the shim 63 from coming off is fastened to the tip of the outer boom 52 with a bolt 67. As a result, the step X in the longitudinal direction between the distal ends of the outer boom 52 and the inner boom 53 is reduced, and the boom length at the time of minimum shortening can be shortened compared to the boom length at the time of maximum extension (for example, Patent Document 1). reference.).

  In addition, the telescopic boom according to Conventional Example 2 has a cross-sectional shape of a polygon to improve rigidity for weight reduction and compactness. Hereinafter, the telescopic boom according to Conventional Example 2 will be described with reference to the attached drawings. FIG. 12 is a half sectional view showing only the base boom (hereinafter referred to as the outer boom) and the second boom (hereinafter referred to as the inner boom) of the telescopic boom according to Conventional Example 2, and FIG. 13 is the pad of the telescopic boom according to Conventional Example 2. FIG. 14 is a cross-sectional view taken along the line CC of FIG. 13, that is, the outer boom 71 of the telescopic boom 70 and the rear side of the inner boom 72 are both rectangular (not shown). And the abdominal surface side is formed in the inverted trapezoidal hexagonal shape. The left and right vertical plate portions in FIG. 12 on the abdominal surface side of the outer boom 71 (only one side is shown), the upper surface of the outer boom lower plate 78 composed of the inclined plate portion and the lowermost horizontal plate portion, A slide plate device 77 having the configuration shown in FIG. 14 is provided.

The entire slide plate device 77 has a rectangular shape in plan view along the boom axis. Reference numeral 80 denotes a slide plate having a rectangular shape in plan view having a long side along the boom axis. A locking claw 82 that can be attached to the lower surface of the slide plate longitudinal direction one end 80a by projecting a part thereof from the longitudinal end surface 80b and an outer boom lower plate upper surface 78a are fixed to the slide plate longitudinal end surface 80b. A regulating member 90 having an engaging surface and a locking portion 92 with the locking claw 82 and restricting the separation of the slide plate longitudinal direction one end 80a from the outer boom lower plate 78, and the slide plate longitudinal direction A locking means 100 for fixing the end surface 80b to the outer boom lower plate 78, and a locking claw shim 110 that can be inserted into the overlapping surface of the slide plate 80 and the locking claw 82; The clearance adjustment is performed by the slide plate portion shim 112 that can be inserted into the overlapping surface with the boom lower plate 78 and has a flat shape excluding the locking claw portion. (E.g., see Patent Document 2.).
JP-A-9-208186 JP 2004-51353 A

  The telescopic booms according to the conventional examples 1 and 2 are considered useful as such. However, the problem of interference during assembly has not been solved yet. Moreover, in a large telescopic boom, since a big force acts on the lower surface side of the overlapping portion of each boom at the time of extension, a configuration that improves the buckling strength by forming the lower surface side into a polygonal shape (conventional example 2). Although proposed, the bent part cannot be supported, and the problem regarding the strength of the telescopic boom remains.

  Accordingly, an object of the present invention is to provide a telescopic boom that is excellent in strength and easy to assemble and insert a boom, despite using a thin steel plate for weight reduction and compactness.

  The present invention has been made in view of the above circumstances. Therefore, in order to solve the above problems, the means employed by the telescopic boom according to claim 1 of the present invention has a cross-sectional shape formed in a deformed cross section. The top upper slide in which each of the inner booms inserted into the outer boom slides on the back side near the tip of each of the outer booms among the adjacent booms. In the telescopic boom in which a pad is provided and a base end slide pad on which an inner peripheral surface of the outer boom into which the inner boom is fitted is slid is provided on the base end side of each inner boom. Each of the booms is individually inserted and inserted inside the abdominal surface near the tip of each of the outer booms, and the ends in the width direction come into contact with each other and are inserted into the outer booms. Wherein the planar shape to achieve a shape along the outer surface of the ventral side of the boom is provided with a plurality of rectangular tip lower slide pad.

  The means adopted by the telescopic boom according to claim 2 of the present invention is such that a plurality of booms each having a cross-sectional cross-sectional shape formed into a deformed cross-section are fitted in a telescope shape, and among the adjacent booms, the tips of the outer booms. The top upper slide pad on which the inner booms inserted into the outer booms are slid is provided on the back side near the inner part, and the inner booms are inserted into the inner booms at the proximal ends of the inner booms. In a telescopic boom provided with a base end slide pad on which a peripheral surface slides, among the adjacent booms, each of the outer booms is in the vicinity of the distal end portion of each outer boom and along the longitudinal direction of the boom. The first pad positioning members provided on both inner side surfaces in the width direction and a predetermined interval in the inner circumferential direction between the inner side surfaces and the inner abdominal surface are provided. A two-pad positioning member and the first pad positioning member and the second pad positioning member are individually fitted and inserted from the tip end side of the boom, and the entire shape is held by the first pad positioning member and the second pad positioning member. A planar shape that realizes a shape along the outer surface of the inner side boom of each inner boom that is inserted into the boom is detachably fixed to a plurality of rectangular lower end lower slide pads and the respective distal end portions of the outer booms, A pad retainer for pressing the end face of the tip lower end slide pad on the tip end side of the boom is provided.

  The telescopic boom according to claim 3 of the present invention is the telescopic boom according to claim 2, wherein the first pad positioning member and the second pad positioning member are disposed on the inner surface of the outer boom. When inserting the inner boom, the proximal end slide pad and the positioning member provided on the proximal end side of each of the inner booms are set so as not to interfere with each other.

  The means adopted by the telescopic boom according to claim 4 of the present invention is the telescopic boom according to any one of claims 2 and 3, wherein the telescopic boom is provided on the back side of the plurality of lower tip slide pads. A third pad positioning member in contact with the end surface of the second pad positioning member on the tip side of the boom is detachably incorporated.

  The means adopted by the telescopic boom according to claim 5 of the present invention is the telescopic boom according to any one of claim 2 or 3, wherein the first telescopic boom is disposed on the back side of the plurality of lower tip slide pads. A greasing device held by a 1-pad positioning member and the second pad positioning member is incorporated.

  The means which the telescopic boom which concerns on Claim 6 of this invention employ | adopted is the telescopic boom of Claim 5. WHEREIN: A 4th pad positioning member is the near side of the said greasing apparatus in the back side of the said greasing apparatus. Further, the third pad positioning member is detachably incorporated.

  The means adopted by the telescopic boom according to claim 7 of the present invention is the telescopic boom according to any one of claim 2 or 3, wherein the lower tip slide pad is located among the adjacent booms. A locking projection that is disposed on the abdominal surface side of each of the outer booms, has an end surface on the back side in contact with the end surface on the distal end side of the boom of the second pad positioning member, and protrudes in a direction opposite to both end portions in the width direction. A first slide pad provided, and a second slide pad provided with engagement notches for restricting the arrangement position by engaging the engaging protrusions of the first slide pad at both ends in the width direction on the back side It is characterized by the following.

  The means adopted by the telescopic boom according to claim 8 of the present invention is the telescopic boom according to any one of claims 1 to 7, wherein the transverse cross-sectional shapes of the lower tip slide pads are adjacent to each other. The width dimension of the inner boom side is formed in a trapezoidal shape smaller than the width dimension of the outer boom side so that the end faces in the width direction of the lower tip slide pad are in surface contact with each other.

  The means adopted by the telescopic boom according to claim 9 of the present invention is the telescopic boom according to any one of claims 1 to 8, wherein the tip lower slide pad has the same thickness on the left and right in the width direction. The same thick slide pad formed on the left side, the left thick slide pad formed on the left side in the width direction is thicker than the right side, and the right thick type slide pad on the right side in the width direction formed thicker than the left side. The slide pads of the respective types are appropriately selected and arranged according to the gap between the outer surface of the inner boom and the inner surface of the outer boom on the ventral side of the boom.

  The means adopted by the telescopic boom according to claim 10 of the present invention is the telescopic boom according to any one of claims 1 to 9, wherein the tip lower slide pad is individually separated by a pad thickness adjusting means. It is characterized in that the thickness can be adjusted.

  The means adopted by the telescopic boom according to claim 11 of the present invention is the telescopic boom according to claim 10, wherein the pad thickness adjusting means is overlapped with the outer boom side surface of the lower tip slide pad and bent. A first shim having a foldable tongue-like projecting piece which is engaged with engaging recesses provided on both sides in the width direction of the lower tip slide pad and protrudes in the width direction, and the first shim and the tip It is comprised from the 2nd shim interposed between the surface by the side of the outer side boom of a lower slide pad, It is characterized by the above-mentioned.

  In the telescopic booms according to claims 1 to 11 of the present invention, among the booms adjacent to each other, the telescopic booms are individually fitted and inserted inside the abdominal surface near the tip of each outer boom, and the ends in the width direction are in contact with each other. Then, the outer surface on the abdominal surface side of the inner boom can be slid by a plurality of lower end slide pads having a rectangular planar shape for realizing a shape along the outer surface on the abdominal surface side of each inner boom to be inserted into the outer boom. It is supported. Therefore, the plurality of lower end slide pads support the corners on the stomach side, which are strong in the structure of the inner boom, and even if a thin steel plate is used for weight reduction and compactness, Since it is excellent, bending deformation of the flat plate portion on the abdominal surface side is suppressed.

Therefore, according to the telescopic boom according to claims 1 to 11 of the present invention, as described above, the outer surface shape on the abdominal surface side of the inner boom is maintained, and the curved deformation of the flat plate portion of the inner boom is suppressed. The following effects can be obtained.
(1) The tip lower slide pad does not wear unevenly, and the telescopic boom does not vibrate abnormally during expansion and contraction.
(2) The amount of bending of the entire telescopic boom can be reduced.
(3) The number of lower end slide pads can be reduced. Further, since the material of the lower tip slide pad can be cut out from the plate material and the yield is good, the lower tip slide pad can be manufactured at low cost.
(4) Even if the tip lower slide pad is unevenly worn, only the unevenly worn tip lower slide pad needs to be replaced, so that the maintenance cost of the telescopic boom is also low.

  According to the telescopic boom according to claim 2 of the present invention, the shape along the outer surface of the inner boom of the inner bottom boom of the plurality of lower tip slide pads having a rectangular planar shape is the first pad positioning member and the second pad positioning member. , And the pad retaining metal prevents the lower slide pad at the distal end from being pulled out from the distal end of the outer boom.

  In the telescopic boom according to the third aspect of the present invention, the positions of the first pad positioning member and the second pad positioning member on the inner surface of the outer boom are determined based on the positions of the inner booms. The base end slide pad provided on the end side and the positioning member are set so as not to interfere with each other. Therefore, according to the telescopic boom according to claim 3 of the present invention, the inner boom can be easily fitted into the outer boom, so that the telescopic boom can be easily assembled.

  In the telescopic boom according to claim 4 of the present invention, the third pad positioning member that comes into contact with the end face of the tip of the boom of the second pad positioning member is detachably incorporated in the back side of the plurality of lower tip sliding pads. . Therefore, according to the telescopic boom according to claim 4 of the present invention, since the entire end surface of the lower tip slide pad is received by the third pad positioning member, the lower tip slide pad is advantageous in terms of strength, Since the 2nd pad positioning member can be made small, it can contribute to the improvement of the assembly nature of a telescopic boom.

  In the telescopic boom according to claim 5 or 6 of the present invention, the plurality of lower tip slide pads are held on the back side of the plurality of lower tip slide pads by the first pad positioning member and the second pad positioning member. A greasing device is incorporated via a third pad positioning member that is pressed against the surface. Therefore, according to the telescopic boom according to claim 5 or 6 of the present invention, the stretchability of the telescopic boom is improved, and it is possible to contribute to the reduction of wear and abnormal vibration of the lower end slide pad. Furthermore, according to the telescopic boom according to claim 6 of the present invention, since the entire end face of the greasing device is received by the fourth pad positioning member, the greasing device is advantageous in terms of strength, and the second Since a pad positioning member can be made small, it can contribute to the improvement of the assembly property of an expansion-contraction boom.

  The distal lower slide pad of the telescopic boom according to claim 7 of the present invention is disposed on the abdominal surface side of each of the outer booms among adjacent booms, and the rear end surface is the distal end of the boom of the second pad positioning member. A first slide pad that is in contact with the side end face and that protrudes in opposite directions at both ends in the width direction, and a locking protrusion of the first slide pad at both ends in the width direction on the back side And a second slide pad provided with an engagement notch for restricting the arrangement position. Therefore, according to the telescopic boom according to claim 7 of the present invention, even if the end surface of the second slide pad is in a free state without coming into contact with the second pad positioning member, the locking projection of the first slide pad Since it is indirectly supported by the second pad positioning member through the engagement notch that engages with the second pad positioning member, there is no need to provide a third pad positioning member.

  In the telescopic boom according to claim 8 of the present invention, the cross-sectional shape of the lower tip slide pad is such that the inner boom side width dimension is the outer side so that the end surfaces in the width direction of the adjacent lower tip slide pads are in surface contact with each other. It is formed in a trapezoidal shape that is smaller than the width dimension on the boom side. Therefore, according to the telescopic boom according to claim 8 of the present invention, since the end surface in the width direction of the lower tip slide pad is in surface contact, the positioning in the width direction of the lower tip slide pad is stabilized and shifted in the width direction. There is no such thing.

  In the telescopic boom according to claim 9 of the present invention, the tip lower slide pad has the same thickness type slide pad formed to have the same thickness on the left and right in the width direction, and the left thickness formed on the left side in the width direction to be thicker than the right side. The right side in the width direction is thicker than the left side, and according to the gap between the outer surface of the inner boom on the ventral side of the boom and the inner surface of the outer boom, Each type of slide pad is appropriately selected and disposed. Therefore, according to the telescopic boom according to claim 9 of the present invention, the cross-sectional shape of the inner boom and the outer boom is dissimilar, and there is a dimensional difference in the width direction of the flat plate portion between the inner boom and the outer boom. Even if there is, the dimensional difference can be absorbed by appropriately selecting and incorporating the same thickness type slide pad, the left thickness type slide pad, and the right thickness type slide pad according to the dimensional difference.

In the telescopic boom according to claim 10 of the present invention, the thickness of the lower slide pad at the tip is individually adjusted by the pad thickness adjusting means. In the telescopic boom according to the eleventh aspect of the present invention, it is overlapped with the outer boom side surface of the lower tip slide pad and is engaged with engagement recesses provided on both sides in the width direction of the lower tip slide pad. And a second shim interposed between the first shim and the outer boom side surface of the lower slide pad at the distal end. Thus, the thickness is individually adjusted.
Therefore, according to the telescopic boom according to the tenth or eleventh aspect of the present invention, the wear of the lower tip slide pad is not uniform, and there is a portion with fast wear and a portion with slow wear, and the lower end of the tip exceeding the allowable wear amount. Since the thickness of the slide pad may be adjusted by the pad thickness adjusting means or shim, the maintenance cost of the telescopic boom can be reduced.

  Hereinafter, the telescopic boom according to the embodiment of the present invention will be described. First, the telescopic boom according to Embodiment 1 of the present invention will be described with reference to the attached drawings. 1 is a side view of the telescopic boom according to Embodiment 1 of the present invention, FIG. 2 is a view taken along arrow A in FIG. 1, the right half shows a basic boom and a first stage boom, and the left half These are figures which show a 1st stage boom and a 2nd stage boom, and FIG. 3 is a side view which shows the arrangement | positioning state of the front-end | tip lower slide pad of the telescopic boom which concerns on Embodiment 1 of this invention. FIG. 4 is an explanatory view of the arrangement positional relationship between the second pad positioning member of the telescopic boom according to Embodiment 1 of the present invention and the proximal lower slide pad on the inner boom proximal end side, and FIG. It is a disassembled perspective view of the pad thickness adjustment means including the tip lower end slide pad of the telescopic boom concerning the first embodiment.

  By the way, FIG. 2 is a figure which shows a basic boom and a 1st stage boom, and a left half part is a figure which shows a 1st stage boom and a 2nd stage boom as above-mentioned. The basic boom is the outer boom 2, and the first boom is the inner boom 3. Further, the first half boom in the left half is the outer boom 2 and the second boom is the inner boom 3. The inner boom is disposed inside the distal end of the outer boom and is inserted into the outer boom. All of the lower slide pads on the tip side that support the tip have the same configuration. Therefore, in the embodiment of the present invention, a description will be given by taking, as an example, a lower tip slide pad that supports a first-stage boom that is an inner boom that is disposed on the inner side of the basic boom and is inserted into the basic boom.

  Reference numeral 1 shown in FIG. 1 is mounted on a front portion of an upper swing body mounted on a tire travel type lower travel body (not shown) so as to be swingable about a vertical axis so as to be raised and lowered by a lifting cylinder. This is a multistage telescopic boom. The telescopic boom 1 is configured by fitting a plurality of booms in a telescope shape. The cross sectional shape of each of the plurality of booms is an irregular cross section as shown in FIG.

  Specifically, the upper back side in FIG. 2 is composed of a horizontal upper plate and vertical side plates, and is formed to have a square shape with R provided at both corners in the width direction. Further, the lower ventral surface side in FIG. 2 is set to be a polygonal shape approximating a semicircle (in the first embodiment, bent ten times, and the flat plate portion at the lowest position in FIG. 2 is horizontal). ) To form a bent shape (hereinafter referred to as a polygonal abdominal surface). Among the adjacent booms fitted in a telescope shape, the R side provided on both sides in the width direction of the inner boom 3 to be fitted to the outer boom 2 is provided on the back side near the tip of the outer boom 2. A tip upper slide pad 4 that slides and has a configuration that will be described later is provided.

  Further, a base end upper slide pad (not shown) on which an inner peripheral surface of the outer boom 2 into which the inner boom 3 is fitted is slid is provided on the base end side of the inner boom 3, and a base lower slide pad is provided. 5 (see FIG. 4). As shown in FIG. 4, the base end lower slide pad 5 is attached to each of flat plate portions of a polygonal abdominal surface formed in a polygonal shape approximate to a semicircle on the base end side of the inner boom 3.

  The sliding surface of the tip upper slide pad 4 is curved so as to contact along the R surface of the corner in the width direction on the back side of the inner boom 3. This tip upper slide pad 4 is inserted and assembled from a pad mounting hole provided in the R surface at the corner in the width direction on the back side of the outer boom 2. The curved sliding surface of the tip upper slide pad 4 is formed by a female screw screwed into an L-shaped bracket 7 bolted to a tapped block 6 provided on the upper plate of the back surface of the outer boom 2. It is configured to be pressed in the horizontal direction in the lower direction in FIG. 2 by the tip end of the press bolt 8 that is screwed and pressed against the R surface at the corner in the width direction on the back side of the inner boom 3.

  Of the booms adjacent to each other, the inner ends of the flat plate portions of the polygonal belly surface formed in a polygonal shape approximating a semicircle near the tip of the outer boom 2 are individually inserted, and the end portions in the width direction are mutually connected. A plurality of lower tip slide pads 10 are provided that come into contact with each other and realize a shape along the outer surface of the polygonal belly surface of the inner boom 3 that is inserted into the outer boom 2. The planar shapes of the plurality of lower tip slide pads 10 are all rectangular and the cross-sectional shape is rectangular. And the shape in alignment with the outer surface of the polygonal belly surface of the inner side boom 3 of these some front-end | tip lower slide pads 10 is comprised by the pad positioning member etc. which are mentioned later.

  The pad positioning member includes three types of pad positioning members, a first pad positioning member 11, a second pad positioning member 12, and a third pad positioning member 13, which will be described later.

  The first pad positioning member 11 is formed of a square bar member having a quadrangular cross-sectional shape, and is adjacent to the distal end portion of the outer boom 2 and the polygonal flat plate portion on the ventral surface side of the outer boom 2 among adjacent booms. It is provided along the longitudinal direction of the boom in the vicinity of the lower ends of the vertical side plates on the back side. The second pad positioning member 12 is a square block having a quadrangular cross-sectional shape, and is near the tip of the outer boom 2 and at a predetermined interval in the inner circumferential direction inside the polygonal belly surface. One is provided. Further, the third pad positioning member 13 is configured such that the end surface on the back side contacts the second pad positioning member 12 and the end surface on the back side of the lower tip slide pad 10 contacts the end surface on the near side. The shape is a polygonal shape that approximates a semicircle, that is, a shape that follows the polygonal abdominal surface of the outer boom 2. The third pad positioning member 13 is detachable and is assembled from the front end side of the boom before the insertion of the lower tip slide pad 10.

  As shown in FIG. 4, the mounting position and interval of the second pad positioning member 12 are determined in consideration of the mounting position and width dimension of the base end lower slide pad 5. That is, when the inner boom 3 having the base end lower slide pad 5 attached to the base end side is fitted into the outer boom 2, the positioning of the base end lower slide pad 5 and the base end lower slide pad 5 is determined. The member is set so as not to interfere with the second pad positioning member 12. Therefore, according to this configuration, the inner boom 3 can be easily fitted into the outer boom 2, so that the telescopic boom 1 can be easily assembled.

  Lower end slide pad that is pushed in from the distal end side of the boom after the insertion of the third pad positioning member 13 until the end surface on the distal end (back side) contacts the end surface on the distal end side of the boom of the third pad positioning member 13 10 is prevented from being pulled out by pad retaining members 16, 16 made of a pair of quarter-circular flat plates fixed by bolts screwed to female screws provided on the end face of the outer boom 2. It is configured. That is, the shape along the outer surface of the polygonal flat plate portion on the abdominal surface side of the inner boom 3 of the plurality of lower tip sliding pads 10 is between the inner surface of the outer boom 2 and the outer surface of the inner boom 3 and a pair of first pads. It is held between the positioning members 11 and between the third pad positioning member 13 and the pad retainer 16.

  Hereinafter, the operation mode of the telescopic boom 1 according to Embodiment 1 of the present invention will be described. That is, in the case of the telescopic boom 1 according to Embodiment 1 of the present invention, among the adjacent booms of the telescopic boom 1, the telescopic booms 1 are individually fitted and inserted inside the polygonal abdominal surface in the vicinity of the tip of each of the outer booms 2. A plurality of lower end slide pads 10 having a rectangular planar shape that achieves a shape along the polygonal abdominal surface of each inner boom 3 that is fitted to the outer boom 2 while the end portions in the width direction are in contact with each other. The polygonal belly surface of the inner boom 3 is slidably supported. For this reason, the plurality of lower end slide pads 10 support the corners between the flat plate portions of the inner side of the inner boom 3 which are structurally strong and have a polygonal abdominal surface. It is suppressed.

Therefore, according to the telescopic boom 1 according to the first embodiment of the present invention, the outer shape of the polygonal belly surface of the inner boom 3 is maintained, and the curved deformation of the flat plate portion of the inner boom 3 is suppressed. The effect of can be obtained.
(1) The tip lower slide pad 10 does not wear unevenly, and the telescopic boom 1 does not vibrate abnormally during expansion and contraction.
(2) The amount of bending of the entire telescopic boom 1 can be reduced.
(3) The types of the lower tip slide pad 10 can be reduced. Further, since the material can be cut out from the plate material and the yield is good, the tip lower slide pad 10 can be manufactured at a low cost.
(4) Even if the tip lower slide pad 10 is unevenly worn, it is only necessary to replace the unevenly worn tip lower slide pad 10, so the maintenance cost of the telescopic boom 1 is also low.

  In the telescopic boom 1 according to the first embodiment of the present invention, as described above, the second pad positioning member 12 is in pressure contact with the end surface on the distal end side of the boom on the back side of the plurality of lower distal end slide pads 10. A 3-pad positioning member 13 is detachably incorporated. Therefore, according to the telescopic boom 1 according to Embodiment 1 of the present invention, since the entire end surface of the lower tip slide pad 10 is received by the third pad positioning member 13, the lower tip slide pad 10 is advantageous in strength. In addition, since the second pad positioning member 12 can be made small, it is possible to obtain an effect that it is possible to contribute to the improvement of the assemblability of the telescopic boom 1.

  Incidentally, as described above, the cross-sectional shape of the lower tip slide pad 10 in the first embodiment is set to a rectangular cross-sectional shape. For example, the width on the inner boom 3 side is larger than the width dimension on the outer boom 2 side. The size can be a small trapezoid. By making the cross-sectional shape of the lower tip slide pad 10 trapezoidal, the end surface in the width direction of the lower tip slide pad 10 comes into surface contact. Therefore, since the positioning in the width direction of the lower tip slide pad 10 is stable and does not shift in the width direction, the outer surface of the flat plate portion of the polygonal belly surface of the inner boom 3 of the plurality of lower tip slide pads 10 is arranged. It can greatly contribute to maintaining the conforming shape stably.

  In addition, the left and right (width direction) thickness of the lower tip slide pad 10 in the first embodiment is only the same thickness, but other than the same thickness slide pad having the same thickness in the left and right direction. Furthermore, a left thick slide pad in which the left side in the width direction is formed thicker than the right side, and a right thick slide pad in which the right side in the width direction is formed thicker than the left side can be used. In this case, according to the gap between the outer surface of the inner boom 3 on the abdominal surface side and the inner surface of the outer boom 2, the slide pads of the respective types are appropriately selected and disposed.

  Thereby, for example, even if there is a dimensional difference in the width direction of the flat plate portion between the inner boom 3 and the outer boom 2, the cross-sectional shape of the inner boom 3 and the outer boom 2 is not similar. The dimensional difference can be absorbed by appropriately selecting and incorporating the slide pad, the left thick slide pad, and the right thick slide pad according to the dimensional difference. In other words, since the entire abdominal surface of the inner boom 3 can be supported without gaps by the plurality of lower tip slide pads, it is possible to prevent abnormal vibration during expansion / contraction of the telescopic boom 1 and increase in deflection of the entire telescopic boom 1. Can do.

  Moreover, the tip lower end slide pad 10 can be configured such that the thickness can be individually adjusted by the pad thickness adjusting means. Hereinafter, the configuration of the pad thickness adjusting means will be described with reference to FIG. 5 of an exploded perspective view of the pad thickness adjusting means including the lower tip slide pad. That is, on the inner boom 3 side surface of the lower tip slide pad 10, engagement recesses 10 a are provided on both sides in the width direction so as to engage the tip of a tongue-like protruding piece described later. And the 1st shim 17 in which the tongue-like protrusion piece 17a engaged with the said engagement recess 10a by bending was provided in the front and back of the both sides of the width direction, and the said front-end | tip lower slide pad 10 and the 1st shim 17 as needed. Between the first shim 17 and the second shim 18 that overlaps the surface of the lower tip slide pad 10 on the outer boom 2 side.

  Therefore, according to the pad thickness adjusting means, the wear of the lower tip slide pad is not uniform, and there are a portion with fast wear and a portion with slow wear. Even if it exceeds, the thickness of only the lower tip slide pad exceeding the allowable wear amount may be adjusted by the first shim 17 or the first shim 17 and the second shim 18, and it is necessary to use a new lower tip slide pad. Therefore, the maintenance cost reduction effect that the maintenance cost of the telescopic boom 1 can be reduced can be obtained.

  A telescopic boom according to Embodiment 2 of the present invention will be described with reference to the accompanying drawings. 6 is a side view showing an arrangement state of a lower end slide pad of a telescopic boom according to Embodiment 2 of the present invention, and FIG. 7 is a cross-sectional view taken along line BB of FIG. The telescopic boom according to the second embodiment of the present invention is different from the telescopic boom according to the first embodiment in the configuration of the lower tip slide pad and the third pad positioning member 13 is not provided. The other components have the same configuration, and thus the same components are denoted by the same reference numerals, and different points will be mainly described.

  That is, among the adjacent booms, the end portions in the width direction are individually inserted into the inner surface side of the flat plate portion of the polygonal belly surface formed in a polygonal shape that approximates a semicircle near the tip of the outer boom 2. A plurality of lower tip slide pads 20 that are in contact with each other and realize a shape along the outer surface of the polygonal belly surface of the inner boom 3 that is inserted into the outer boom 2 are a first slide pad 21 and a second slide pad that will be described later. 22 and two types of lower end slide pads.

  The first slide pad 21 is provided with locking protrusions 21a that protrude in opposite directions at both ends in the width direction on the back side. Further, the second slide pad 22 is provided with engagement notches 22a that engage with the locking projections 21a of the first slide pad 21 to restrict the arrangement position at both ends in the width direction on the back side. ing. That is, the first slide pad 21 and the second slide pad 22 are alternately inserted from the front end side of the boom, but after the first slide pad 21 is inserted, the second slide pad 22 is inserted and inserted. 2 The engagement notch 22 a of the slide pad 22 is configured to engage with the locking protrusion 21 a of the first slide pad 21.

  The pad positioning members that hold the first slide pad 21 and the second slide pad 22 in a shape that follows the outer shape of the polygonal abdominal surface of the inner boom 3 are the first pad positioning member 11 and the second pad positioning member 12. It is made up of. On the end surface of the second pad positioning member 12 on the front end side of the boom, a second slide pad 22 whose end in the width direction contacts the first pad positioning member 11, and an end in the width direction of the second slide pad 22 The end surface on the back side of the first slide pad 21 with which the end portion in the width direction comes into contact with the portion, and the end surface on the back side of the first slide pad 21 that is inserted and inserted into every second slide pad 22 one by one hereinafter. Are configured to contact each other.

  According to the telescopic boom 1 according to the second embodiment of the present invention, even if the end surface of the second slide pad 22 is not in contact with the end surface of the second pad positioning member 12 and is in a free state, the first slide pad 21 is indirectly supported by the second pad positioning member 12 through an engagement notch 22a that engages with the locking protrusion 21a of the 21. Therefore, it is not necessary to provide the third pad positioning member like the telescopic boom according to the first embodiment, and the same effect as the telescopic boom according to the first embodiment can be obtained. That is, according to the telescopic boom 1 according to Embodiment 2 of the present invention, the outer shape of the polygonal belly surface of the inner boom 3 is maintained by the first slide pad 21 and the second slide pad 22, and the flat plate of the inner boom 3. Since the bending deformation of the part is suppressed, the same effect as the telescopic boom 1 according to the first embodiment can be obtained.

In addition, although the cross-sectional shape of the 1st slide pad 21 and the 2nd slide pad 22 of the telescopic boom 1 which concerns on this Embodiment 2 is set to the rectangle, the outer boom 2 side is the same as the case of the said Embodiment 1. FIG. The width of the inner boom 3 can be made smaller than that of the trapezoid.
In addition to the same thickness slide pad with the same thickness in the left and right direction, the left thick slide pad is formed with the left side in the width direction being thicker than the right side, and the right thickness is formed with the right side in the width direction being thicker than the left side. A mold slide pad can be used. Furthermore, each of the first slide pad 21 and the second slide pad 22 can be configured such that the thickness can be individually adjusted by the pad thickness adjusting means.

  A telescopic boom according to Embodiment 3 of the present invention will be described with reference to the accompanying drawings. FIG. 8 is a side view of the distal end portion of the telescopic boom according to the third embodiment of the present invention, and FIG. 9 is a side view showing an arrangement state of the lower slide pad at the distal end of the telescopic boom according to the third embodiment of the present invention. . The telescopic boom according to the third embodiment is different from the telescopic boom according to the first embodiment in that the greasing device and the fourth pad positioning are located on the back side of the lower tip slide pad according to the first embodiment. Since the other members have the same configuration, the same components are denoted by the same reference numerals, and different points will be mainly described.

  In the third embodiment of the present invention, as shown in FIG. 8, a predetermined interval is provided in the inner peripheral direction between the polygonal abdominal surfaces near the distal end portion of the proximal boom that is the outer boom 2 of the telescopic boom 1. A plurality of grease gun holes 1a are provided for inserting a grease gun in order to supply grease to a grease nipple that is screwed to a grease supply device to be described later. Although not shown in the drawings, the first boom, which is the inner boom 3 that is inserted into the proximal boom that is the outer boom 2, and the second boom that is inserted into the first boom, which is the inner boom 3, are the following. A plurality of grease gun holes are provided on all booms.

In other words, as shown in FIG. 9, the distal end lower slide pad 10 is disposed in the middle portion of the long hole-like nipple arrangement recess 9 a via the third pad positioning member 13. A plurality of rectangular grease supply devices 9 to which grease is supplied from the grease nipple 15 are incorporated.
And the end surface of the back side of the 4th pad positioning member 14 which contacts the end surface of the back side of this grease supply apparatus 9 is contact | abutting to the end surface of the boom pad end side of the said 2nd pad positioning member 12. FIG. The greasing device 9 is made of sponge-like rubber and can be assembled from the tip side of the boom. The grease nipple 15 is fixed to the inner surface of the boom with an adhesive (trade name: Loctite).

  The fourth pad positioning member 14 has the same shape and the same size as the third pad positioning member 13. The fourth pad positioning member 14 and the third pad positioning member 13 are integrally formed via a greasing device 9 interposed between them at a predetermined interval. Thus, the 4th pad positioning member 14, the 3rd pad positioning member 13, and the greasing apparatus 9 were integrally formed aiming at the easy assembly of these.

In the case of the telescopic boom 1 according to Embodiment 3 of the present invention, as described above, the overall shape is formed by the first pad positioning member 11 and the second pad positioning member 12 on the back side of the plurality of lower tip slide pads 10. A plurality of rectangular grease supply devices 9 are incorporated via third pad positioning members 13 that are held and pressed by the plurality of lower tip slide pads 10.
Therefore, according to the telescopic boom 1 according to the third embodiment of the present invention, the outer shape of the polygonal abdominal surface of the inner boom 3 is held by the lower tip slide pad 10, and the curved deformation of the flat plate portion of the inner boom 3 is suppressed. Therefore, the same effect as the telescopic boom 1 according to the first embodiment can be obtained.

  Further, according to the telescopic boom 1 according to the third embodiment of the present invention, since the greasing device 9 is incorporated, the stretchability of the telescopic boom 1 is improved, and the wear of the lower tip slide pad 10 is further reduced. And can contribute to the reduction of abnormal vibration. Furthermore, since the entire end face of the greasing device 9 is received by the fourth pad positioning member 14, the greasing device 9 is advantageous in terms of strength, and the second pad positioning member 12 can be made smaller. It can contribute to the improvement of the assembly property of the telescopic boom 1.

  A telescopic boom according to Embodiment 4 of the present invention will be described with reference to the accompanying drawings. FIG. 10 is a side view showing an arrangement state of the tip lower slide pad of the telescopic boom according to Embodiment 4 of the present invention. Note that the telescopic boom according to the fourth embodiment is different from the telescopic boom according to the third embodiment in the configuration of the lower tip slide pad, and the other components are the same in the configuration, so that the same reference numerals are used. The difference is mainly described.

In the case of the telescopic boom according to the fourth embodiment of the present invention, as well understood in the comparison between FIG. 10 and FIG. 9 showing the third embodiment, the lower tip slide pad 10 in the third embodiment is This is a configuration in which the lower end slide pad having the configuration shown in FIG. 5 is replaced.
That is, the first shim 17 is attached by engaging the tongue-like protruding piece 17a with the engagement recess 10a provided on the inner boom 3 side surface of the lower tip slide pad 10, or the lower tip slide pad 10 and the first A second shim 18 is interposed between the shim 17 and the tip lower slide pad 10 so that the thickness of the slide pad 10 can be individually adjusted.

  Therefore, according to the telescopic boom according to the fourth embodiment of the present invention, the lower tip slide pad 10 in the third embodiment is simply replaced with the lower tip slide pad having the configuration shown in FIG. An effect equivalent to that of Form 1 can be obtained. Also, the wear of the lower tip slide pad is not even, there are parts with fast wear and slow wear, and even if the thickness of the lower slide pad exceeds the allowable wear amount, the allowable wear amount was exceeded. The thickness of only the lower tip slide pad may be adjusted by the first shim 17 or the first shim 17 and the second shim 18, and it is not necessary to use a new lower tip slide pad. The maintenance cost can be reduced.

  The telescopic booms according to the first to fourth embodiments described above are merely specific examples, and the present invention is not limited to the configuration of the telescopic boom according to the first to fourth embodiments, and the technology of the present invention. The design can be freely changed without departing from the spirit of the idea.

It is a side view of the telescopic boom which concerns on Embodiment 1 of this invention. In FIG. 1A, the right half shows the basic boom and the first stage boom, and the left half shows the first stage boom and the second stage boom. It is a side view which shows the arrangement | positioning state of the front-end | tip lower slide pad of the telescopic boom which concerns on Embodiment 1 of this invention. It is arrangement | positioning positional relationship explanatory drawing of the 2nd pad positioning member of the telescopic boom which concerns on Embodiment 1 of this invention, and the base end lower slide pad of the base end side of an inner side boom. It is a disassembled perspective view of the pad thickness adjusting means including the tip lower end slide pad of the telescopic boom according to Embodiment 1 of the present invention. It is a side view which shows the arrangement | positioning state of the front-end | tip lower slide pad of the telescopic boom which concerns on Embodiment 2 of this invention. It is the BB sectional view taken on the line of FIG. It is a side view of the front-end | tip part of the telescopic boom which concerns on Embodiment 3 of this invention. It is a side view which shows the arrangement | positioning state of the front-end | tip lower slide pad of the telescopic boom which concerns on Embodiment 3 of this invention. It is a side view which shows the arrangement | positioning state of the front-end | tip lower slide pad of the telescopic boom which concerns on Embodiment 4 of this invention. It is a top sectional view of a sliding member device (corresponding to a tip lower part slide pad) of a telescopic boom concerning conventional example 1. FIG. 10 is a half cross-sectional view showing only a base boom (hereinafter referred to as an outer boom) and a second boom (hereinafter referred to as an inner boom) of an extendable boom according to Conventional Example 2; It is a top view of the pad (equivalent to a front-end | tip lower slide pad) of the telescopic boom which concerns on the prior art example 2. FIG. It is CC sectional view taken on the line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Telescopic boom, 1a ... Grease gun hole 2 ... Outer boom 3 ... Inside boom 4 ... Top end slide pad 5 ... Base end bottom slide pad 6 ... Tapped block 7 ... L-shaped bracket 8 ... Press bolt 9 ... Supply Grease device, 9a ... nipple disposition recess 10 ... lower tip slide pad, 10a ... engagement recess 11 ... first pad positioning member 12 ... second pad positioning member 13 ... third pad positioning member 14 ... fourth pad positioning Member 15 ... Grease nipple 16 ... Pad retaining bracket 17 ... First shim, 17a ... Tongue protruding piece 18 ... Second shim 20 ... Lower tip slide pad 21 ... First slide pad, 21a ... Locking projection 22 ... Second Slide pad, 22a ... engagement notch

Claims (11)

  A plurality of booms each having a cross-sectional shape with an irregular cross-section are fitted in a telescope shape, and among the adjacent booms, the inner sides of the outer booms are inserted into the rear sides of the outer booms. The top slide pad for sliding the boom is provided, and the base end slide pad for sliding the inner peripheral surface of the outer boom into which the inner boom is fitted is provided on the base end side of each inner boom. In the telescopic boom, each of the adjacent booms is individually inserted and inserted into the abdominal surface near the tip of each outer boom, and the ends in the width direction are in contact with each other and are inserted into the outer boom. A telescopic boom comprising a plurality of lower tip slide pads having a rectangular planar shape that realizes a shape along an outer surface of the inner boom of the inner boom.   A plurality of booms each having a cross-sectional shape with an irregular cross-section are fitted in a telescope shape, and among the adjacent booms, the inner sides of the outer booms are inserted into the rear sides of the outer booms. The top slide pad for sliding the boom is provided, and the base end slide pad for sliding the inner peripheral surface of the outer boom into which the inner boom is fitted is provided on the base end side of each inner boom. In the telescopic boom, a first pad positioning member provided on both inner side surfaces in the width direction of each of the outer booms in the vicinity of the distal end portion of each of the outer booms among the adjacent booms and along the longitudinal direction of the boom. A second pad positioning member provided at a predetermined interval in the inner circumferential direction between the both inner side surfaces and the inner abdominal surface, and individually from the tip side of the boom The outer shape of each of the inner booms that is inserted and inserted into the outer boom while being inserted into the outer boom with the end portions in the width direction coming into contact with each other with the first pad positioning member and the second pad positioning member holding the entire shape. Are attached to the tip portions of the plurality of lower tip slide pads having a rectangular shape and the outer boom, and press the end surfaces of the tip ends of the plurality of lower tip slide pads. A telescopic boom characterized in that a pad retaining metal fitting is provided.   The arrangement positions of the first pad positioning member and the second pad positioning member on the inner side surface of the outer boom are the base end slide pads provided on the base end sides of the inner booms when the inner booms are fitted. The telescopic boom according to claim 2, wherein the telescopic boom is set so as not to interfere with the positioning member.   The third pad positioning member that comes into contact with the end surface of the tip of the second pad positioning member on the back side of the plurality of lower tip sliding pads is detachably assembled. The telescopic boom according to any one of the above.   The greasing device held by the first pad positioning member and the second pad positioning member is incorporated in the back side of the plurality of lower tip slide pads. The telescopic boom according to any one of the above.   The expansion and contraction according to claim 5, wherein a fourth pad positioning member is detachably incorporated in the back side of the greasing device, and a third pad positioning member is detachably incorporated in the front side of the greasing device. boom.   The tip lower slide pad is disposed on the abdominal surface side of each of the outer booms among the adjacent booms, the rear end surface is in contact with the end surface of the second pad positioning member on the tip end side of the boom, and the width direction The first slide pad provided with locking projections projecting in opposite directions at both ends of the first slide pad, and the engagement positions of the first slide pad are engaged with the locking projections of the first slide pad at both end portions in the width direction. The telescopic boom according to any one of claims 2 and 3, wherein the telescopic boom comprises a second slide pad provided with an engaging notch to be regulated.   The cross-sectional shape of the lower tip slide pad is such that the inner boom side width dimension is smaller than the outer boom side width dimension so that the end faces in the width direction of adjacent lower tip slide pads are in surface contact with each other. The telescopic boom according to any one of claims 1 to 7, wherein the telescopic boom is formed in a shape.   The lower tip slide pad has the same thickness on the left and right in the width direction, the left thick slide pad on the left in the width direction thicker than the right, and the left on the right in the width direction. Each type of slide pad is appropriately selected according to the gap between the outer surface of the inner boom on the ventral side of the boom and the inner surface of the outer boom. The telescopic boom according to any one of claims 1 to 8, wherein the telescopic boom is disposed.   The telescopic boom according to any one of claims 1 to 9, wherein the tip lower slide pad is configured to be individually adjustable in thickness by a pad thickness adjusting means.   The pad thickness adjusting means is overlapped on the outer boom side surface of the lower tip slide pad, and is engaged with engagement recesses provided on both sides in the width direction of the lower tip slide pad by bending and protruding in the width direction. A first shim having a foldable tongue-shaped projecting piece provided, and a second shim interposed between the first shim and the outer boom side surface of the lower tip slide pad. The telescopic boom according to claim 10.

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