JP3631404B2 - Telescopic boom boom structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a boom structure for a telescopic boom that is telescopically inserted (inserted) into each other and operates to extend and contract, and more particularly, to a structure for discharging foreign matter that enters the telescopic boom.
[0002]
[Prior art]
The telescopic booms as described above are widely used as booms for crane devices and aerial work devices, etc., and telescopic operations of telescopic cylinders arranged inside a multi-stage boom and between each constituent boom. The telescope is configured to be telescopically movable in the direction in which the boom extends by the action of a connecting wire or the like.
[0003]
In such a telescopic boom, in addition to the telescopic cylinder and telescopic wire as described above, a hydraulic hose, a signal line, a sheave (pulley) for stretching these telescopic wire and hydraulic hose, etc. A sliding member or the like that is supported so as to be extendable and retractable is disposed. For this reason, foreign objects such as metal pieces and dust enter between the boom members at the distal end of each boom member (for example, the proximal boom, the intermediate boom, and the distal boom) constituting the multistage boom, In order not to adversely affect the sliding portion, a scraper that elastically presses a resin material, a thin metal plate, or the like toward the outer surface of the boom member that is inscribed from the outer boom member is attached. It was configured to scrape off foreign matters such as dust that would adhere to the boom surface and enter the inside of the boom.
[0004]
[Problems to be solved by the invention]
The scraper as described above has a certain effect with respect to scraping off foreign matter such as dust that adheres to the gap of the boom member or the boom surface and enters the inside of the boom. However, once such a scraper bites a foreign object such as a metal piece or a granular piece adhering to the boom surface, there is a gap around it and the scraping effect is temporarily reduced. In the case of a scraper made of plastic, plastic deformation may occur due to contact with foreign matter itself or surrounding structures, and in such a case, the scraping effect is significantly reduced, and it is not possible to completely prevent foreign matter from entering. Have difficulty.
[0005]
The foreign matter that has entered the inside of the boom in this way is subjected to the reverse action that it is pushed into the inside of the boom when the boom is extended by the scraper. In particular, in the type of boom that involves hoisting operation, when the boom is tilted and tilted, the scraper scraping action and gravity action causes the inner boom surface to face the base end of the boom. There is a problem that the roll may fall and adversely affect the sheaves and sliding parts inside the boom. For example, in an aerial work vehicle that performs shot processing after welding of a large structure, hard shot grains enter the boom, and bite into a sheave disposed at the base end of the intermediate boom, There was a problem that there was a risk of damaging the elastic cables and damaging them.
[0006]
The present invention has been made in view of the above problems, and foreign matters such as metal pieces and granular pieces that have entered the boom without being removed by the scraper are caused by the reverse action or gravity action of the scraper. An object of the present invention is to provide a boom structure for a telescopic boom that does not adversely affect a sheave, a telescopic cylinder, or the like disposed in the boom even when it falls to the end.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problem, in the present invention, a long first boom having a hollow cross section (for example, the proximal boom 5a in the embodiment) and a telescopic fit by being telescopically inserted into the first boom. A boom of a telescopic boom having a second boom configured to be movable (for example, the intermediate boom 5b in the embodiment) and changing a boom length by operating the second boom to extend and contract with respect to the first boom. in construction, proximal end of the second boom to actuate the proximal outer surface of the second boom facing the first boom of the inner surface (e.g., embodiments in top 5b _t or side 5b _v), the telescopic boom A slope member (e.g., a hose sheave 18 in the embodiment or a pivoting portion of the telescopic cylinder 13 in the embodiment) that is located on the tip end side of the second boom and protrudes toward the inner surface of the first boom. Eg real And the slope member covers the entire front side of the structure when viewed from the distal end side of the second boom, and the distal end of the second boom. A tilting surface that tilts downward from the distal end side of the second boom toward the proximal end side in the tilting posture of the telescopic boom with the portion positioned above the base end portion of the first boom, and the tilting posture of the telescopic boom The position where the foreign matter falling toward the structure from the distal end side of the second boom does not collide with the structure (for example, the middle boom left and right sides outside the hose sheave 18 in the embodiment, the pivoting portion of the telescopic cylinder 13) (Below the lower intermediate boom), and is made to fall.
[0008]
According to such a structure, it is located in the front end side of a 2nd boom rather than the structure arrange | positioned in the base end part of the 2nd boom in the base end part outer surface of the 2nd boom inserted in the 1st boom. And the slope member which protrudes toward the 1st boom inner surface which counters is provided , and this slope member covers the whole front of the above-mentioned structure when seeing the base end side from the tip side of the 2nd boom, In the tilting posture of the telescopic boom, it has an inclined surface that tilts downward from the distal end side to the proximal end side of the second boom, and collides foreign matter falling from the distal end side of the second boom toward the structure. It is configured to be guided to a position where it does not fall. For this reason , for example, foreign objects such as metal pieces and granular pieces that are not removed by the scraper provided between the first boom and the second boom and fall between the booms are moved downward by an arbitrary inclination by the slope member. Can lead. Therefore, such a slope member is provided in the vicinity of the structure disposed at the base end portion of the second boom, and the above-mentioned problems are solved by guiding the foreign material to a site that does not adversely affect it. It is possible to provide a boom structure for a telescopic boom with improved reliability.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the boom structure of the telescopic boom according to the present invention will be described with reference to the drawings. First, FIG. 1 shows a perspective view of a wheel-type self-propelled aerial work vehicle (hereinafter referred to as “aerial work vehicle”) having a telescopic boom structure according to the present invention. To do. The aerial work vehicle 1 is provided on a vehicle body 3 configured to be able to travel by the action of a travel motor (not shown), and a swivel 4 configured to be pivotable in a horizontal direction with respect to the vehicle body 3 by the operation of a swing motor 11. At the upper end of the swivel 4, a boom 5 configured to be movable up and down with respect to the vehicle body 3 by the expansion and contraction operation of the hoisting cylinder 12 is pivotally attached.
[0010]
The boom 5 includes a base end boom 5a, an intermediate boom 5b, and a front end boom 5c that are pivotally attached to the swivel 4, and each is telescopically inserted into the telescopic cylinder 13 to extend and retract. The telescopic cylinder 13 is configured to be stretchable by the action of an telescopic wire (both not shown) wound around a wire sheave that moves in accordance with the telescopic operation of the telescopic cylinder 13. At the tip of the boom 5, a vertical post 6 that is always kept vertical regardless of the undulation angle of the boom 5 is provided by operating a leveling cylinder (not shown), and further, by operating a swing motor provided on the vertical post. A work table 8 configured to swing freely around the vertical post 6 is attached.
[0011]
The work table 8 is provided with an operating device 10 for operating the vehicle and operating the boom 5, and an operator on the work table 8 operates the operating device 10 to operate the vehicle. The hydraulic actuators such as the motor, the turning motor 11, the hoisting cylinder 12, and the telescopic cylinder 13 are operated to move the work vehicle 1 to the intended site position, and the boom 5 is swung, hoisting, telescopic, etc. Thus, the work table 8 can be moved to an arbitrary high place to perform a desired high place work.
[0012]
FIG. 2 shows the state of each boom distal end of the base end boom 5a, the intermediate boom 5b, and the distal end boom 5c when the boom 5 is fully contracted. Scrapers 31, 31,..., 32, 32,. The scraper 31 attached to the proximal boom 5a and the scraper 32 attached to the intermediate boom are formed by punching a thin plate-like resin material such as polymer rubber into a predetermined shape, and facing the outer surface of the boom that is fitted inside. The outer surface of the boom is bent and slidably pressed on the outer surface of the inner boom, and the outer periphery of the standing surface extending in the outer peripheral direction of the boom is fixed to the flange surface of the outer boom by a fastening means (not shown) such as a screw.
[0013]
Thus, since the scrapers 31 and 32 are elastically slidably pressed from the outer boom toward the outer surface of the inner boom, the boom 5 can be freely expanded and contracted by the expansion and contraction operation of the telescopic cylinder 13 and the like. In addition, the gaps between the boom members are sealed in a curtain shape, and foreign objects such as metal pieces and granular materials adhering to the boom surface are scraped off at the scraper end surface. To prevent entering.
[0014]
However, as described above, the foreign matter removal effect of these scrapers 31 and 32 is not completely perfect, and the removal effect decreases with the passage of the use period. The foreign matter that has entered the interior is swept off toward the base end side (left side in FIG. 2) of the boom by the reverse action of the scraper.
[0015]
FIG. 1 shows the state of the boom base end when the boom 5 is fully contracted, with the outer surface of a part of the base end boom 5a broken away. The right side in FIG. 1 is the boom tip side (working table 8 side) where the scrapers 31 and 32 are disposed, and the left side in the drawing is the base end side (swivel table 4 side) of the boom 5. The proximal boom 5a is pivotally attached to the upper end of the swivel 4 at a boss 51 below the boom, and is configured to be movable up and down around the pivot shaft. That is, when the boom 5 is operated up and down, the vicinity of the pivot shaft corresponds to the lowermost end portion of the boom 5.
[0016]
The base end of the intermediate boom 5b fitted into the base end boom 5a is moved together with the intermediate boom 5b between the distal end of the base end boom whose distance changes when the boom 5 is extended and retracted and the work table. Accordingly, a hose sheave 18 for feeding and storing the wound hydraulic hose of a certain length in the boom is disposed. Since the hydraulic hose (not shown) wound around the hose sheave 18 is required to have bending durability, a synthetic rubber hose with blade reinforcement is used, and high-pressure hydraulic oil flows through the internal oil passage. . Therefore, the adhering adhesion of hard foreign matters such as metal pieces and shot grains near the hose sheave 18 can be a big problem for the boom device.
[0017]
For this reason, in the present invention, the foreign matter mixing prevention structure 20 is provided at the base end portion of the intermediate boom that is above the hose sheave 18 when the boom 5 is raised and lowered. The structure 20 includes a top face member 21 that protrudes is disposed on the upper surface 5b _t of the intermediate boom 5b upward, are disposed on both side surfaces 5b _v and side members 22, 22 projecting laterally (these Corresponds to the slope member in the claims, and is formed of a plate-like body or a rod-like body as shown in the drawing, and forms inclination angles θ ₁ , θ ₂ with respect to the telescopic operation direction of the intermediate boom 5b. Then, it is fixed to the intermediate boom 5b. In this way, inclined surfaces 21a and 22a are formed that protrude from the outer surface of the intermediate boom 5b toward the inner surface of the proximal boom 5a facing each other with inclination angles θ ₁ and θ ₂ .
[0018]
In addition, the required height (namely, protrusion height of both members) of the said inclined surface in the upper surface member 21 and the side surface member 22 changes with the uses and functions of the working apparatus comprised using the boom 5. FIG. For example, when the maximum undulation angle of the boom 5 is small and the entering foreign matter is a fine granular material such as sand dust, the protruding height of the member is 30 with respect to the gap between the proximal boom 5a and the intermediate boom 5b. % Has an effective effect. On the other hand, in the case where the maximum undulation angle of the boom 5 is large and the entering foreign matter is an irregular shape such as a metal piece or shot grain, the member height is preferably 50% or more with respect to the gap. Further, when high-temperature foreign matter such as welding sparks or grinder chips is mixed, it is required to be made of metal.
[0019]
The inclination angle θ ₁ of the upper surface member 21 is generally higher in the effect of rectifying and discharging foreign matters when the angle is smaller, and the retention amount of foreign matters increases as θ ₁ becomes larger (closer to the direction of expansion and contraction of the boom 5). Tend to be. However, if θ ₁ is increased, a state of contact with each other when the intermediate boom is fully extended in relation to the above-described scraper 31 is caused, or the total length of the boom is increased. Therefore, by forming the convex upper surface member 2 divided, as shown in FIG. 1, to shorten the boom longitudinal dimension, and, taking a high rectifying discharging effect the inclination angle theta ₁ is increased to Can do.
[0020]
Further, in the mounting position relationship between the upper surface member 21 and the side surface member 22, both the members are maintained while maintaining the rectifying effect by attaching the side surface member 22 to the upper surface member 21 while being offset (Off) toward the boom base end side. The processing accuracy and mounting accuracy required by the machine can be reduced, facilitating production and cost reduction.
[0021]
And the upper surface member 21 and the side surface member 22 which were formed in this way are fixed to the intermediate | middle boom 5b with the fastening means matched with the member. For example, the upper surface member 21 and the side surface member 22 are formed by cutting a flat bar and fixed by fastening means such as welding or bolts. Alternatively, these are formed of a synthetic resin material such as nylon and fixed by fastening means such as bolts and rivets. Further, in order to completely close the gap, the intermediate boom mounting side is made of a metal material, and the portion in contact with the inner surface of the base end boom is made of a resin material, and is fixed by the above-described means.
[0022]
According to the foreign matter mixing prevention structure 20 configured as described above, the foreign matter enters the gap between the proximal boom 5a and the intermediate boom 5b and is swept down toward the proximal end of the boom by the reverse action of the scraper 31. among them, the foreign matter that has rolled down toward the upper top surface 5b _t of the intermediate boom 5b in the boom base end, intermediate boom side as indicated by an arrow a inclined surface 21a of the top face member 21, by 21a in Figure 1 Guided in the direction.
[0023]
Foreign matter guided by the upper surface member 21 from the intermediate boom top 5b _t the side surface of the intermediate boom 5b, and the boom base 5a and the foreign matter that has fallen between the intermediate boom 5b from the boom tip side is provided in the intermediate boom side 5b _v As shown by an arrow B in FIG. 1, the side member 22 guides the base end boom lower surface 5 _ab . Then, in this way the foreign matter guided on the base end boom lower surface 5a _b, the C in the figure by this foreign matter that has rolled down over the lower surface from the boom tip side inclination of the boom 5, as indicated by arrows in D It is discharged from the base end portion of the base end boom 5a to the outside of the boom.
[0024]
In this way, foreign matter that has entered the boom 5 by the action of the disposed a tamper-resistant structure to the intermediate boom 5b 20 (top face member 21 and side members 22, 22), the intermediate boom top 5b _t intermediate boom sides _5b v, is guided to 5b _v and proximal boom lower surface 5a _b. Accordingly, it is possible to prevent foreign matter from entering a structure such as the hose sheave 18 or the telescopic cylinder existing in the region below the boom inclination than the foreign matter mixing prevention structure 20. Can be improved.
[0025]
The upper surface member and the side surface member only have to have an inclined surface inclined with respect to the boom telescopic axis, and the planar view shape thereof is, for example, a curved surface shape (23) as shown in FIG. A single bar configuration (24) as shown in FIG. 4 (b) or a single convex plate configuration (25) as shown in FIG. 4 (c) may be used. In addition, the cross-sectional shape of the inclined surface with which the foreign object abuts is not only the cross-sectional shape orthogonal to the upper surface member or the like as shown in FIG. 1, but is inclined toward the boom tip as shown in FIG. 5A, for example. It is good also as a structure provided with the scraper 35 similar to a boom front-end | tip part as shown in an inclined surface structure (26), a curved surface structure (27) as shown in FIG.5 (b), and FIG.5 (c).
[0026]
Moreover, although the above description demonstrated the intermediate | middle boom 5b which has a rectangular shape, it can apply similarly to any boom inserted in other booms, such as the front-end | tip boom 5c, and also the cross-sectional shape of a boom is the same. Even if it has a circular cross section, it can be similarly applied. In the case of such a boom having a cross-sectional shape, the upper surface member and the side surface member can be integrated to form, for example, a spiral shape.
[0027]
【The invention's effect】
As described above, the present invention has the second boom that is telescopically inserted into the first boom having a hollow cross section, and is configured to be extendable and retractable. The second boom is extended and retracted with respect to the first boom. In the boom structure of the telescopic boom to be operated, the outer surface of the second boom facing the inner surface of the first boom is located on the outer side of the structure provided at the proximal end of the second boom, A slope member projecting toward the inner surface of one boom is provided, and this slope member covers the entire front of the structure when viewed from the distal end side of the second boom, and in an inclined posture of the telescopic boom. It has an inclined surface that inclines downward from the distal end side to the proximal end side of the second boom, and collides with a foreign member falling from the distal end side of the second boom toward the structure in the inclined posture of the telescopic boom so as to fall leading position to not It is formed. For this reason, foreign matters such as metal pieces and granular pieces falling between these booms can be guided by the slope member downward and discharged, and thereby the structure disposed at the second boom base end portion. It is possible to provide a boom structure for a telescopic boom that prevents a foreign substance from entering and adhering to a member and adversely affects the member and improves reliability.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a preferred embodiment of a boom structure of a telescopic boom according to the present invention.
FIG. 2 is a perspective view showing a front end portion of the boom structure.
FIG. 3 is an explanatory diagram for explaining a configuration of an aerial work vehicle equipped with the telescopic boom.
FIG. 4 is a plan view showing another preferred embodiment in the boom structure of the telescopic boom according to the present invention.
FIG. 5 is a cross-sectional view showing another preferred embodiment of the slope member in the boom structure of the telescopic boom according to the present invention.
[Explanation of symbols]
5 Telescopic boom 5a Base boom (first boom)
5b Intermediate boom (second boom, first boom)
5c Tip boom (second boom)
21 Upper surface member (slope member)
22 Side members (slope members)
23, 24, 25 Upper surface member (slope member)
26, 27, 28 (35) Top member (side member, slope member)

Claims (1)

An elongated first boom having a hollow cross section; and a second boom that is telescopically inserted into the first boom and configured to be extendable and retractable. 2 A boom structure of an extendable boom that changes the boom length by operating the boom to extend and contract,
The distal end of the second boom rather than the structure provided at the proximal end of the second boom for operating the telescopic boom on the outer surface of the proximal end of the second boom facing the inner surface of the first boom A slope member that is located on the side and projects toward the inner surface of the first boom;
The slope member covers the entire front of the structure when the base end side is viewed from the distal end side of the second boom, and the distal end portion of the second boom is above the proximal end portion of the first boom. The telescopic boom is positioned at a tilted surface that tilts downward from the distal end side of the second boom toward the base end side in the tilted posture of the telescopic boom, and from the distal end side of the second boom in the tilted posture of the telescopic boom. A boom structure for a telescopic boom, wherein foreign matter falling toward the structure is guided and dropped to a position where it does not collide with the structure.

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