CN211687996U - Crane boom self-balancing structure - Google Patents

Abstract

The invention relates to a self-balancing structure of a crane boom. A self-balancing structure of a crane boom comprises a parallelogram mechanism, a gear mechanism, a plurality of pulleys and pulley sets, a steel wire rope (2), and the like. According to a certain winding method of the steel wire rope, the tension of the steel wire rope (2) gives the torque of the upper balance rocker (6) and the lower balance rocker (11) through the transformation of the parallelogram mechanism and the gear mechanism, which can balance the goods through the steel wire rope for the lifting and shaking. The torque of the rod (3) can realize the self-balancing of the boom under the weight of the goods, and it can reduce the luffing resistance. When the boom is luffed, the goods only have horizontal displacement, which can reduce the power consumption of the luffing and reduce the motor capacity. and power functions.

Description

A self-balancing structure of a crane boom

technical field

The invention relates to the field of construction machinery, in particular to a self-balancing structure of a crane boom.

Background technique

Boom cranes are widely used in ports, construction and other fields, and have the characteristics of high power and high energy consumption, so the improvement of crane energy saving is of great significance.

In jib cranes, the main function of boom luffing is to make the goods have horizontal displacement, and at the same time, the luffing will also cause the goods to produce vertical displacement; that is, the boom luffing leads to the change of the potential energy of the goods. This means that the boom cannot achieve self-balancing under the action of cargo gravity. This type of structure has the following disadvantages: 1. It increases the capacity and performance requirements of the motor that controls the rotation of the rocker arm, 2. The rotation of the rocker arm will consume more energy, including lifting the cargo, braking and decelerating, etc. 3. The inertia of the cargo in the vertical direction will Increase the luffing resistance, 4. For the crane whose rocker arm is controlled by the hydraulic system, when the rocker arm is stationary, leakage will also waste a part of the energy.

In order to solve or reduce the vertical displacement caused by the boom luffing to the cargo, there are currently two main methods: 1. Rope compensation method, that is to lengthen or shorten the hoisting rope while luffing; 2. Combined boom The compensation method relies on the special movement of the combined boom to make the goods move horizontally.

The rope compensation method can reduce the luffing resistance, but it cannot solve the shortcomings of the large capacity of the required motor, the large power consumption, and the large luffing energy loss. The combined boom compensation method solves the above problems, but its design is complicated, the boom structure is heavy, and the crane's range of motion is limited.

Therefore, it is necessary to design a suitable boom structure to reduce the luffing resistance, reduce the motor capacity and power, and reduce the luffing loss.

Utility model content

The technical problem to be solved by the present invention is how to realize the self-balancing of the rocker arm of the crane, thereby reducing the capacity of the boom drive motor, reducing the energy consumption of the motor, and reducing the luffing resistance of the rocker arm.

In order to realize the above functions, a self-balancing structure of a crane boom proposed by the present invention includes a parallelogram mechanism, a gear mechanism, a plurality of pulleys and pulley groups, a wire rope, and the like. One end of the wire rope (2) is connected to the goods through the No. 1 pulley (4), and one end passes through the No. 2 pulley (15) along the lifting rocker (3), and then passes through the No. 3 pulley along the direction parallel to the pull rod (5). (7), then pass the No. 4 pulley (9) along the upper balance rocker (6), then pass the No. 5 pulley (10) vertically downward, and then pass the No. 6 pulley along the lower balance rocker (11) The pulley (14) is finally connected to the power source and the transmission case (12). The parallelogram mechanism is composed of a hoisting rocker (3), a pull rod (5), an upper balance rocker (6), and a frame, wherein point B, point C, point D, and point E are hinge points, and the hoisting rocker The lever (3) and the upper balance rocker (6) are kept parallel. The gear mechanism is composed of a No. 1 gear (16), a No. 2 gear (13), and a lower balance rocker (11). The No. 1 gear (16) and the No. 2 gear (13) are externally meshed and the transmission ratio is 1; The No. 1 gear (16) rotates coaxially and at the same angle with the lifting rocker (3), and the No. 2 gear (13) rotates at the same angle with the lower balance rocker (11). The included angle between the rocker (3) and the lower balance rocker (11) and the horizontal direction is equal. The lengths of the lower balance rocker (11) GH and the EF part of the upper balance rocker (6) are equal, and the point E and the point H are on the same vertical line, then the point F and the point G are on the same vertical line , and the wire rope (2) between the fourth pulley (9) and the fifth pulley (10) is along the vertical direction.

Further, in order to reduce the length of the EF part of the upper balance rocker (6) and the lower balance rocker (11), the fourth pulley (9) and the fifth pulley (10) can use a pulley block; The balance effect, the number of pulleys, the EF part of the upper balance rocker (6), the lower balance rocker (11) GH, and the lifting rocker (3) AC should maintain a certain mathematical relationship; that is, n×L _AC = 2×L ×(2N-1), where n is the ratio of the cargo gravity to the wire rope tension T, L _AC is the length of the lifting rocker (3) AC, L is the EF part of the upper balance rocker (6) and the lower balance rocker (11) The length of GH, their lengths are equal, N is the number of pulleys covered by the fourth pulley (9) and the fifth pulley (10), and the number of pulleys they cover is equal.

Further, in order to facilitate the overall installation and avoid interference, when the No. 1 gear (16) and the No. 2 gear (13) are engaged, the center line between the two can be rotated. If the central position of the No. 1 gear (16) is fixed, Then the center position of the No. 2 gear (13) is on the arc with the center of the No. 1 gear (16) as the center and the diameter of the gear as the radius, and the hinge point E of the upper balance rocker (6) and the No. 2 gear (13) ), the center point H remains on the same vertical line.

Advantages and beneficial effects of the invention: The invention applies the common parallelogram mechanism and gear mechanism to the crane jib system, and solves the problem that the jib needs to be balanced by external force under the action of cargo gravity. The present invention has the following advantages: 1. The present invention realizes the self-balancing of the boom. When the hoisting rocker (3) needs to be variable, the cargo only has a horizontal displacement, and the motor driving the rotation of the boom theoretically only needs to overcome the friction force and the inertial force. , the braking deceleration power is also greatly reduced, which greatly reduces the capacity of the motor and the electric energy consumed by the motor, and has the effect of energy saving; 2. The present invention reduces the amplitude resistance of the crane and makes the amplitude variable faster; 3. The invention is suitable for cranes with jib structure, and also suitable for cranes with longer lifting rocker (3). suitable for practical use.

Description of drawings

FIG. 1 is a schematic diagram of Embodiment 1 of the self-balancing structure of the crane boom according to the present invention.

FIG. 2 is a schematic diagram of Embodiment 1 of the self-balancing structure of the crane jib according to the present invention.

3 is a schematic diagram of Embodiment 2 of the self-balancing structure of the crane boom according to the present invention.

4 is a schematic diagram of the winding mode of the wire rope (2) on the fourth pulley (9) and the fifth pulley (10) according to the second embodiment of the self-balancing structure of the crane boom according to the present invention.

FIG. 5 is a schematic diagram of Embodiment 2 of the self-balancing structure of the crane boom according to the present invention.

6 is a schematic diagram of Embodiment 3 of the self-balancing structure of the crane boom according to the present invention.

FIG. 7 is a schematic diagram of Embodiment 3 of the self-balancing structure of the crane boom according to the present invention.

Description of main symbols

1 cargo, 2 steel wire rope, 3 lifting rocker, 4 No. 1 pulley, 5 tie rod, 6 upper balance rocker, 7 No. 3 pulley, 8 tower, 9 No. 4 pulley, 10 No. 5 pulley, 11 lower balance rocker , 12 Power source and transmission box, 13 No. 2 gear, 14 No. 6 pulley, 15 No. 2 pulley, 16 No. 1 gear

Detailed ways

The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Fig. 1 is an embodiment disclosed in the present invention. The self-balancing structure of the boom includes a parallelogram mechanism, a gear mechanism, a plurality of pulleys and pulley sets, and a wire rope (2). The parallelogram mechanism includes a lifting rocker (3), a pull rod (5), an upper balance rocker (6) and a frame, wherein the lifting rocker (3) is hinged with the frame at point C, and the pull rod (5) is connected It is hinged with the hoisting rocker (3) and the upper balance rocker (6) at points B and D respectively, and the upper balance rocker (6) is hinged with the tower (8) at point E. In the parallelogram mechanism, the hoisting rocker (3) is parallel to the upper balance rocker (6), and their included angles with the horizontal direction are equal. The gear mechanism includes a No. 1 gear (16), a No. 2 gear (13), and a lower balance rocker (11). The No. 1 gear (16) and the No. 2 gear (13) are a pair of external meshing gears with a transmission ratio of 1. Using a certain connection method, the No. 1 gear (16) and the lifting rocker (3) rotate coaxially and at the same angle, and the No. 2 gear (13) and the lower balance rocker (11) rotate coaxially and at the same angle, so the lifting rocker The rod (3) and the lower balance rocker (11) rotate in opposite directions at the same speed. Through the installation method of key connection, the included angle between the lifting rocker (3) and the lower balance rocker (11) and the horizontal direction is equal. To sum up, the included angles of the lifting rocker (3), the upper balance rocker (6), and the lower balance rocker (11) and the horizontal direction are equal.

Pulleys include No. 1 pulley (4), No. 2 pulley (15), No. 3 pulley (7), No. 4 pulley (9), No. 5 pulley (10), No. 6 pulley (14); they are installed at the end of the connecting rod Part or middle, responsible for the winding of the wire rope. The No. 6 pulley (14) is concentric with the No. 2 gear (13), and the No. 2 pulley (15) is concentric with the No. 1 gear (16); this can theoretically eliminate the torque of the wire rope here on the connecting rod.

The winding of the wire rope (2) plays an important role in the self-balancing structure. One end of the wire rope (2) is connected to the goods, firstly passes through the No. 1 pulley (4), and then reaches the No. 2 pulley (15) along the lifting rocker (3). And go around the No. 2 pulley (15) for more than half a turn, then follow the direction parallel to the pull rod (5) to the No. 3 pulley (7), and then follow the direction of the upper balance rocker (6) to reach the No. 4 pulley (9) , and then reach the No. 5 pulley (10) along the vertical downward direction, and then reach the No. 6 pulley (14) along the lower balance rocker (11) and go around the No. 6 pulley (14) for more than half a turn, and finally connect to the A power source and a transmission case (12).

FIG. 2 is a schematic diagram of the self-balancing structure of the above embodiment. By independently analyzing the moment balance of each connecting rod, it can be deduced that under the action of the gravity of the cargo, the structure can achieve self-balancing. The parallelogram mechanism and the gear mechanism make the included angles of the hoisting rocker (3), the upper balance rocker (6), and the lower balance rocker (11) equal to the horizontal direction. In addition, point E and point H are on the same vertical line, and point F and point G are on the same vertical line. First, due to the hinged connection between the connecting rod and the frame, the supporting force of the frame on the connecting rod will not generate torque on the connecting rod. Second, since the pulley does not transmit torque, the force of the wire rope (2) on the pulley will pass through the pulley pair. The force of the connecting rod produces torque. In the figure, the force of the wire rope (2) on the No. 3 pulley (7), No. 6 pulley (14), and No. 2 pulley (15) is transmitted to the frame and does not contribute to the torque. In addition, after the force of the wire rope on the No. 1 pulley (4), No. 4 pulley (9), and No. 5 pulley (10) is transmitted to the connecting rod, the force arm along the AC, FE, GH directions is zero, so the opposite rotation moment does not contribute. Therefore, the torque of the wire rope tension T to each connecting rod can be obtained from the analysis of the forces acting at points A, F and G along the vertical direction.

This structure not only has certain requirements for the wire rope winding, but also has certain requirements for the length of the connecting rod. In this embodiment, the EF part of the upper balance rocker (6) is required to be the same length as the lower balance rocker (11) GH, and It is equal to half of the length of the hoisting rocker (3) AC, ie L _EF =L _GH =0.5×L _AC =0.5×L1, L1=L _AC . According to the above analysis, the torque M6=-0.5×T×L1×COS(θ) (clockwise) generated by the tension of the wire rope on the upper balance rocker (6), and the torque generated by the tension of the wire rope on the lower balance rocker (11) M11=0.5×T×L1×COS(θ) (counterclockwise), the torque M3=T1×L1×COS(θ) (counterclockwise) generated by the pulling force of the wire rope on the hoisting rocker (3). The parallelogram mechanism and gear mechanism play a key role in the self-balancing of the structure. In the quadrilateral mechanism, the torque about the point E received by the upper balance rocker (6) will be equally transmitted to the lifting rocker (3) with the point C as the rotation center. The gear mechanism reversely transmits the torque about the H point received by the lower balance rocker (11) to the hoisting rocker (3) with the rotation center at the C point. To sum up, the torque of the hoisting rocker (3) about point C is M=M3+M6-M11=0. Through the above derivation, the torque of the hoisting rocker (3) about point C is always 0, which has nothing to do with the angle between the hoisting rocker (3) and the horizontal direction, so the rocker arm does not consume additional energy to perform work on the goods when the rocker is luffing. , so when the rocker arm is luffed, the height of the cargo remains unchanged, and the boom structure achieves self-balancing. Therefore, the structure can greatly reduce the luffing resistance of the crane, reduce the luffing power consumption, and reduce the capacity and power of the motor.

In addition to this method, when the rocker arm rotates, the height of the cargo remains unchanged and the total length of the wire rope (2) remains unchanged, which can also prove that the boom has achieved self-balancing.

According to the above description, L _EF =L _GH =0.5×L _AC =0.5×L1, but in practice the length of the hoisting rocker arm L _AC is very large, which leads to the large size of the parallelogram mechanism and the gear mechanism, which is not suitable for practical applications. used in the scene.

Fig. 3 is the second embodiment disclosed by the present invention, which is an improved solution for reducing the size of the parallelogram mechanism and the gear mechanism. It differs from Embodiment 1 in that the No. 4 pulley (9) and No. 5 pulley (10) in Embodiment 1 are single pulleys, while in Embodiment 2, the No. 4 pulley (9) and the No. 5 pulley ( 10) A pulley block is used.

Figure 4 depicts the winding method of the wire rope (2) on the fourth pulley (9) and the fifth pulley (10). According to this winding method, the magnitude of the force of the wire rope (2) on the upper balance rocker (6) and the lower balance rocker (11) changes.

Fig. 5 is a schematic diagram of the present embodiment. According to the analysis of Fig. 2, in Fig. 5, the torques generated by the wire rope tension on the upper balance rocker (6) and the lower balance rocker (11) at points E and H respectively can be determined by The total wire rope tension acting on points F and G is calculated. If the pulling force on the wire rope is T, and there are N pulleys on the No. 4 pulley (9) and No. 5 pulley (10) respectively, then according to the analysis, the total pulling force acting on the F point and the G point can be obtained as (2N-1)× T. Assuming that the EF part of the upper balance rocker (6) and the length of the lower balance rocker (11) GH are L, to make the crane jib achieve self-balancing, L should satisfy T×L1×COS (θ)=2×T ×L×COS(θ)×(2N-1), that is, L1=2×L×(2N-1). In an actual crane, the cargo will also use a pulley block, and at this time, the total pulling force of the wire rope received by the lifting rocker (3) will be multiplied, which is the gravity of the cargo. Assuming that the cargo gravity G=n×T, the dimension relationship of the connecting rod is n×L1=2×L×(2N-1).

Fig. 6 is the third embodiment disclosed by the present invention, which differs from the first embodiment in the installation positions of the second gear (13) and the first gear (16). In Embodiment 1, the center line of the No. 2 gear (13) and the No. 1 gear (16) is in the horizontal direction, while in Embodiment 3, the center line of the No. 1 gear (16) can be in any direction. If the center position is fixed, the center position of the No. 2 gear (13) is on the arc with the center of the No. 1 gear (16) as the center and the diameter of the gear as the radius, and the hinge point E of the upper balance rocker (6) is The center point H of the second gear (13) remains on the same vertical line.

Figure 7 is a schematic diagram of the present embodiment. If the center position of the No. 1 gear (16) is fixed, the center position of the No. 2 gear (13) is in the circle with the center of the No. 1 gear (16) as the center and the gear diameter as the radius. and the hinge point E of the upper balance rocker (6) and the center point H of the second gear (13) remain on the same vertical line; assuming their positional relationship is in the state shown in the figure, for The theoretical derivation in FIG. 2 is still applicable, so this embodiment can still achieve self-balancing of the boom.

Claims (4)

1. A self-balancing structure of a crane jib, comprising a parallelogram mechanism, a gear mechanism, a plurality of pulleys and pulley blocks, and a wire rope (2), characterized in that: the parallelogram mechanism is composed of a lifting rocker (3), a pull rod ( 5), the upper balance rocker (6), and the frame, wherein the lifting rocker (3) is parallel to the upper balance rocker (6), and the length of the BC part of the lifting rocker (3) is the same as the upper balance rocker The length of the DE part of (6) is equal, the length of the tie rod (5) BD is equal to the length of CE, the point C is the rotation center of the lifting rocker (3), and the point E is the rotation center of the upper balance rocker (6). The gear mechanism is composed of the second gear (13), the first gear (16) and the lower balance rocker (11). The second gear (13) and the first gear (16) are a pair of gears with a transmission ratio of 1. The external meshing gear, the No. 2 gear (13) and the lower balance rocker (11) are fixedly connected and rotated, the No. 1 gear (16) is fixedly connected and rotated with the lifting rocker (3), and the lifting rocker (3), the lower The angle between the balance rocker (11) and the horizontal direction is equal; one end of the wire rope (2) is connected to the cargo, firstly passes through the No. 1 pulley (4), and then reaches the No. 2 pulley (15) along the lifting rocker (3). ) and go around the No. 2 pulley (15) for more than half a turn, then follow the direction parallel to the pull rod (5) to the No. 3 pulley (7), and then follow the direction of the upper balance rocker (6) to reach the No. 4 pulley (9). ), and then along the vertical downward direction to the fifth pulley (10), then along the lower balance rocker (11) to the sixth pulley (14) and around the sixth pulley (14) for more than half a turn, and finally connect to the power source and gearbox (12). 2. The crane boom self-balancing structure according to claim 1, characterized in that: the EF part of the upper balance rocker (6) of the parallelogram mechanism and the lower balance rocker (11) of the gear mechanism The lengths of the GH parts are equal, and the point E and the point H are on the same vertical line, then the point F and the point G are also on the same vertical line. 3. The self-balancing structure of the crane boom according to claim 1, characterized in that: the lifting rocker (3) of the parallelogram mechanism, the EF part of the upper balance rocker (6) and the lower balance of the gear mechanism The length of the GH part of the rocker (11) has a certain mathematical relationship; n×L _AC = 2×L×(2N-1), where n is the ratio of the cargo gravity to the wire rope tension T, and L _AC is the lifting rocker (3) The length of AC, L is the length of the EF part of the upper balance rocker (6) and the length of the lower balance rocker (11) GH, their lengths are equal, N is the fourth pulley (9) and the fifth pulley (10) ) cover the number of pulleys, and they cover the same number of pulleys. 4. The self-balancing structure of the crane jib according to claim 1, characterized in that: the direction of the center line connecting the No. 2 gear (13) and the No. 1 gear (16) of the gear mechanism can be changed, if the No. 1 gear (16) The center position of the gear (16) is fixed, then the center position of the No. 2 gear (13) is on the arc with the center of the No. 1 gear (16) as the center and the gear diameter as the radius; the upper balance rocker of the parallelogram mechanism The hinge point E of the lever (6) and the center point H of the second gear (13) are kept on the same vertical line.

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