RU2305064C1 - Jib crane - Google Patents

Abstract

FIELD: mechanical engineering; special cranes.

SUBSTANCE: invention relates to level luffing jib cranes. Proposed jib crane has running truck with travel motion mechanism of which turning platform support is installed, platform with load with winch, platform turning mechanism, vertical and horizontal jib fastening trusses, counterweights and control cabin arranged and secured on platform. Jib is made in form of flat structure of seamless pipes with braces and load suspension and it hinge connected with vertical trusses and furnished also with two lower struts made in form of steel rods with absorbers and hinge connected with jib at distance of 0.3-0.4 of jib reach from axis of its attachment to platform trusses. Counterweights of crane are L-shaped in cross section, are vertically fitted in sockets and are made in form of rigid frame of H-section bars connected with upper platform and resting by projection on frame.

EFFECT: improved reliability, efficiency and safety of operation of jib crane.

4 cl, 7 dwg

Description

The invention relates to the construction of special cranes with an unchanged angle of inclination of the boom and is intended for use in transshipment of various cargoes, mainly scrap metal, as well as for loading and unloading rolling stock.

A known design of a crane-manipulator installation, which contains a slewing ring, remote outriggers, a single-section boom, a hoisting winch and a hook suspension (Pat. RU No. 2240971, IPC 7 V66C 23/00, publ. 20.03.2004).

The disadvantage of this design when loading and unloading wagons is very limited visibility from the control point of the installation of the wagon space and a possible loss of stability when dumping the cargo.

A known construction of a crane with a rotary platform and a lifting boom having a special wire rope calculation associated with a chain hoist having movable and fixed clips, between which traction is made of rigid articulated links connected to the clips (Pat. RU No. 2254285, IPC 7 В66С 23 / 26, publ. 06/20/2005).

During loading and unloading operations with the dumping of cargo by this crane, the rope calculation of the boom does not provide the necessary rigidity of the boom, which can lead to its swinging.

A known design of a reloading portal crane, comprising a portal in the form of a spatial frame, supported by running trolleys, a rotary part, which consists of a platform with hoisting, turning, boom change, electrical equipment and control cabs, columns and boom mounted directly or articulated (see Gokhberg M.M. Handbook of cranes. T.2. L .: Mechanical engineering. 1988, p.106, fig .IY.4.1).

These cranes are widely used for loading and unloading rolling stock, and cars move between the columns of the portal of the crane. However, in the cramped conditions of scrap collecting sites, the use of cranes of this design has significant limitations associated with the low maneuverability and bulkiness of the crane and the absence in its design of vibration damping mechanisms that occur during a sudden discharge of cargo.

Closest to the claimed one is a loader crane, including a portal with balanced chassis trolleys, a cylindrical tower made of sheet, a counterweight console with counterweights attached to it from below, a load winch, a swing mechanism, an arrow made in the form of a spatial lattice structure, and a cabin, located at the level of the boom of the crane (Pat. RU No. 2172291, IPC 7 В66С 23/00, publ. 08.20.2001).

The disadvantages of this design of the crane are:

- the implementation of the arrows of the spatial-lattice structure without damping mechanisms when dumping the load, which leads to the swinging of the crane with a sharp dumping of the load, for example a pack or briquette of scrap;

- hanging the balances from the bottom under the counterweight console, which reduces the size from the rails to the lower point of the counterweight and can cause the counterweights to hit the wagon or other structures when turning the crane, and also reduces the safety of people working in the crane operating area;

- finding the control cabin at the boom level directly on the platform makes it difficult for the crane operator to see and often requires a slinger at the bottom.

The aim of this invention is to increase the reliability, efficiency and safety of the crane in the conditions of scrap platforms by improving its structural elements and their relative position.

This goal is achieved by the fact that the crane is a jib type, including a traveling trolley with a movement mechanism, on which the support of the turntable is mounted, directly the platform with a cargo winch, the mechanism of rotation of the platform, vertical and horizontal boom mounts, counterweights and a control cabin fixed to the platform, the boom with stretch marks and the cargo suspension connected with the trusses is made with the boom in the form of a flat structure from seamless pipes, pivotally connected to vertical trusses, forming their vertical axis has an angle of 72 °, which is equipped with two lower braces, made in the form of steel rods with shock absorbers, pivotally connected to the platform and the boom, and the balances are L-shaped in cross section, mounted vertically in sockets made in the form of a rigid frame made of I-beams beams connected to the upper platform and the protrusion rest on the frame.

In addition, the shock absorber of the lower boom of the boom is made in the form of an all-welded fork with a stop, in which hollow bushings of elastic material are tightly fitted and a cylindrical rod with a spring passing inside the bushings, which has the possibility of reciprocating movement and connected to the spring by means of nuts through plate washers.

The lower braces are connected to the boom at a distance of 0.3-0.4 departure of the boom from the axis of its attachment to the trusses of the platform.

The control cabin is installed directly below the boom in such a way that the distance from the front wall of the cabin to the axis of the boom cargo block is not more than 0.8 boom outreach.

The invention is illustrated by drawings, where figure 1 shows a General view of the crane, and figure 2 - design of a shock absorber lower braces of the boom. In addition, the invention is illustrated by photographs, where Figs. 3 and 4 show a general view of the crane and the location of the balances, Fig. 5 is an external view of the shock absorbers of the lower brackets of the boom, Fig. 6 is a fragment of the boom with the points of attachment of the rods of the lower braces to it, 7 is a crane control cabin and a view from it.

The crane consists of a running trolley 1 (see figure 1), which is made in the form of a rigid frame from longitudinal box-section beams connected by welding. On top of the frame, a steel sheet floor is welded onto which the annular support of the crane column is fixed. On the platform of the undercarriage 1 there is a mechanism for moving the crane 2, consisting of drive and idle wheels with flanges, a gearbox, shafts and an electric motor with a brake. A column 3 made of a sheet in the form of a pipe with inner ribs and flanges for fastening the column 3 to the frame of the carriage and the slewing device 4 is rigidly bolted to the annular support of the undercarriage 1 with bolts. The slewing device 4 is made in the form of a rolling support with upper and lower discs and rollers between them. The lower disk of the device 4 is made stationary and has an internal gear providing rotation of the crane platform 5 to which the upper disk is bolted. The rotary platform 5 is made in the form of a rigid frame of beams with stiffeners for attaching the upper disk of the slewing ring 4 connected by welding and covered by a sheet floor welded to the beams. On the platform 5 are installed: cargo winches 6, a rotation mechanism 7, a spatial frame 8 of horizontal 9, vertical 10 and inclined 11 farms, as well as a crane control cabin 12, which is installed under the boom 13 at a certain distance from its head. A frame 14 of I-beams with nests, in which counterweights 15 are placed, is attached to the rear of the platform 5 in the form of concrete boxes filled with concrete, having a L-shaped cross section. A fence 16 is installed around the perimeter of the platform 5, and a ladder 17 is permanently attached to it from the outside to raise and lower the platform. On the platform deck 5, cabinets with electric equipment of the crane are placed. The boom of the crane 13, made in the form of a tubular frame structure, in the head of which a cargo block 18 is mounted, is pivotally connected to the vertical trusses 10. The stationary position of the boom 13 and a certain angle of its inclination are provided by the upper cable ties 19 connected to the inclined trusses 11 of the frame 8. Bottom the boom 13 is pivotally connected by braces 20, made in the form of steel rods with shock absorbers 21, to vertical trusses 10, which provides additional stability and rigidity of its position. The hinges 22 of the connection of the braces 20 to the crane arm are located at a distance of 0.3-0.4 of the boom 17 from the axis of its attachment to the vertical trusses 10. In the streams of the cargo block 18 there are ropes connecting the cargo winch 6 and the hook suspension 23, consisting of a block , hook mounted in the traverse, and the body.

Shock absorbers 21 (see FIG. 1) are made in the form of an all-welded fork 24 (see FIG. 2) with a stop in which elastic hollow bushings 25 of square section are tightly mounted. A cylindrical rod 26 with a spring 27 mounted on it passes inside the bushings 25. A certain position of the spring 27 relative to the rod 26 is ensured by fixing it with nuts 28 through the disk washers 29. Using the nuts 28, the stiffness of the shock absorbers 21 can be changed (see Fig. 1). The cylindrical rod 26 (see figure 2) is rigidly connected to a steel rod 30, which, in turn, through the eyes is pivotally connected to the boom 13 of the crane (see figure 1). The plug 24 (see figure 2) through the eyes pivotally connected to the platform 5 (see figure 1).

This crane works as follows. The undercarriage 1 (see figure 1) of the crane is installed on the crane tracks. The movement is carried out by a pair of drive wheels, the rotation of which is transmitted from a common gearbox of the crane movement mechanism 3 through intermediate shafts with gear couplings. In turn, the gear drive is carried out through the coupling and shaft from the electric motor. The movement mechanism also has an electro-hydraulic brake. It is possible to carry out a crane movement drive with a torque transmission to each drive wheel from a separate electric motor with a gearbox.

The rotation of the platform 5 of the crane and the boom 13 with the load is carried out from a vertically mounted electric motor through a gearbox with an electromagnetic brake. On the output shaft of the gearbox there is a gear engaged with the ring gear of the slewing ring 4. The rotation of the pinion provides the necessary angle of rotation of the boom 13. The rotary device is equipped with a limiter of the angle of rotation of the platform 5.

The load is lifted by transmitting torque from the electric motor to the drum of the cargo winch 6, on which helical grooves are cut and the ends of the rope are fixed with fasteners. The half hoist of the cargo winch is 6 single-branch. The rope of the cargo winch 6 passes through the blocks mounted on the frame 8 of the platform 5, in the boom head 13 and in the hook suspension 25. When the drum of the winch 6 is rotated, the rope is winded or reeled up, thereby raising or lowering the load.

In the conditions of scrap platforms, this crane works mainly with an electromagnet or a grab. An additional winch 6 is installed on the platform 5 of the crane for working with a mechanical grab, working to close and open the grab. It is possible to use an electric grab on this crane. When loading and unloading rolling stock, the crane can work with a hook suspension.

When overloading scrap metal in briquettes or in bulk (see Figures 3 and 4), the crane drives up to the place of scrap storage, picks up and lifts the load with an electromagnet or grab and moves along crane tracks to the place of its loading into open wagons, storage or briquetting. Highly located on the platform 5 (see Fig. 1) of the crane, the counterweights 15 (see Fig. 1 and Fig. 4) of the original form allow it to move freely with the possibility of rotation of the boom 13 in rather cramped conditions of the site. When lifting and transporting the load, the rods 30 (see FIG. 2) of the lower braces 20 (see FIG. 1) of the boom 13 due to the adjusting nuts 28 (see FIG. 2) of the shock absorbers are coaxial with the plug 24. At the moment of opening the grab or de-energized the electromagnet load is sharply dropped, while the arrow 13 (see figure 1) tends to move up. However, due to the fact that the lower braces 20 of the boom 13 have shock absorbers 21, there is a movement of the rod 30 (see figure 1) of the brace and the rod 26 of the shock absorber rigidly connected with it (see figure 5), which soften the spring and elastic bushings . Thus, the oscillatory movement of the boom is suppressed, which increases the stability of the crane as a whole and helps to increase the resource of work and the safety of the upper rope extensions and booms. With a crane carrying capacity of 5 tons, which is enough for overloading scrap metal, the boom reach is 13 meters with a mass of counterweights of 14 tons. For a crane with such parameters, the maximum damping of the boom vibrations occurs when the hinges of attaching the lower brace to the boom are located at a distance of 3.9-5.2 meters from the axis of attachment of the boom to the vertical trusses of the turntable frame (see Fig. 6).

When loading and unloading wagons, for example, with scrap metal for a given boom reach and location of the front part (glazing) of the control cabin at a distance of no more than 10.4 meters from the axis of the boom cargo block, the crane operator has a good overview (see Fig. 7) and can see fully carriage space and work without helpers below.

Thus, the result of this invention is to increase the reliability, efficiency and safety of jib cranes in the conditions of scrap platforms by changing its structural elements and optimizing their relative position.

Claims (4)

1. A boom-type crane, including a running trolley with a moving mechanism, on which a support for the turntable is mounted, directly a platform with a cargo winch, a platform turning mechanism, vertical and horizontal boom mounting trusses, counterweights and a control cabin fixed to the platform, a boom with extensions and a cargo suspension connected to the trusses, characterized in that the crane arm, made in the form of a flat structure of seamless pipes, is pivotally connected to vertical trusses, forming from their vert the angle of the axis is 72 °, and is equipped with two lower braces made in the form of steel rods with shock absorbers pivotally connected to the platform and the boom, and the balances are L-shaped in cross-section, mounted vertically in sockets made in the form of a rigid frame from I-beams connected to the upper platform and the protrusion rest on the frame. 2. The crane according to claim 1, characterized in that the shock absorber of the lower boom of the boom is made in the form of an all-welded fork with a stop in which hollow bushings of elastic material are tightly mounted and a cylindrical rod with a spring passing inside the bushings having the possibility of reciprocating movement and connected to the spring by means of nuts through plate washers. 3. The crane according to claim 1, characterized in that the lower braces are connected to the boom at a distance of 0.3-0.4 outreach from the axis of its attachment to the platform trusses. 4. The crane according to claim 1, characterized in that the control cabin is installed directly under the boom so that the distance from the front wall of the cabin to the axis of the load block of the boom is not more than 0.8 outreach.

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