Lifting device and crane with same

Abstract

The utility model provides a lifting device and a crane with the lifting device, and the lifting device comprises a mounting seat, a lifting mechanism and a lifting mechanism, the hoisting mechanism comprises a winding drum and a rope, the winding drum is rotatably arranged on the mounting seat, the rope is wound on the winding drum, and the rope is connected with a hoisted piece; the driving piece is in driving fit with the drum; the speed reducing structure is arranged between the driving piece and the winding drum; the braking structure is provided with a braking position and an avoiding position, and when the braking structure is located at the braking position, the braking structure is in braking fit with the speed reduction structure; the tension sensing piece is arranged on the rope; the controller is in signal connection with the driving part, the braking structure and the tension sensing part; and when the lifted piece is in the free falling working mode and the measured value of the tension sensing piece is smaller than or equal to the preset force value, the braking structure is switched to the braking position from the avoiding position. According to the technical scheme, the problem that in the prior art, when a lifted piece freely falls, the rotating stopping time of the winding drum cannot be accurately controlled is effectively solved.

Description

Technical Field

[0001] The utility model relates to the technical field of lifting equipment, and in particular to a hoisting device and a crane having the same. Background Art

[0002] A railway crane is a crane that travels and works on railway rails, and is mainly used in railway lines, construction departments, factories and mines to complete railway locomotive and vehicle accident rescue, line construction and maintenance, and cargo loading and unloading. When the railway crane is working, it often repeatedly lifts and lowers heavy objects in a short period of time, which requires it to have good lifting and lowering speeds.

[0003] The lifting and lowering speeds of a railway crane are controlled by a hoisting structure, and the power of the hoisting structure is provided by a hoisting motor and a hoisting motor. The speed of the object during lifting is determined by the parameters of the two themselves. When the heavy object is lowered, in order to increase the lowering speed of the heavy object, the free-fall method can be adopted. When the hoisting structure uses the free-fall function, the heavy object only falls freely under the action of gravity. This kind of lowering method can not only get rid of the speed limit of the hoisting motor and the motor, but also save energy consumption.

[0004] However, in the prior art, when the heavy object falls freely, the braking of the hoisting mechanism of the crane depends on a manual method, and it is difficult to grasp the braking timing. Premature braking is likely to cause the crane to additionally bear the additional load caused by the inertia of the heavy object, resulting in a safety accident. Delayed braking will cause the wire rope to be over-released. Summary of the Utility Model

[0005] The main purpose of the present utility model is to provide a hoisting device and a crane having the same, so as to solve the problem in the related art that the timing of the stop rotation of the drum cannot be accurately controlled when the lifted object falls freely.

[0006] To achieve the above object, according to one aspect of the present utility model, a hoisting device is provided, including: a mounting seat; a hoisting mechanism, the hoisting mechanism includes a drum and a cable, the drum is rotatably arranged on the mounting seat, the cable is wound around the drum, and the cable is connected to the lifted object; a driving member, the driving member is drivingly engaged with the drum; a deceleration structure, the deceleration structure is arranged between the driving member and the drum; a braking structure, arranged on the mounting seat, the braking structure has a braking position and an avoidance position, when the braking structure is in the braking position, the braking structure is brakingly engaged with the deceleration structure, or the braking structure is brakingly engaged with the drum; a tension sensing member, the tension sensing member is arranged on the cable; a controller, the controller is in signal connection with the driving member, the braking structure and the tension sensing member; wherein, when the lifted object is in the free-fall working mode and the measured value of the tension sensing member is less than or equal to a preset force value, the controller controls the braking structure to switch from the avoidance position to the braking position.

[0007] Further, the braking structure has a braking position for braking cooperation with the deceleration structure and a avoiding position for avoiding the deceleration structure. The braking structure includes a two-position three-way solenoid valve and a brake connected to the two-position three-way solenoid valve. When the braking structure switches from the avoiding position to the braking position, the driving fluid enters the brake through the two-position three-way solenoid valve, so that the brake is in braking cooperation with the deceleration structure.

[0008] Further, the brake includes a cylinder block, a brake rod disposed through the cylinder block, and a reset member disposed between the brake rod and the cylinder block. The rodless cavity of the cylinder block is communicated with the two-position three-way solenoid valve. When the braking structure switches from the avoiding position to the braking position, the driving fluid enters the rodless cavity through the two-position three-way solenoid valve and presses the brake rod to move towards the deceleration structure to brake the deceleration structure.

[0009] Further, the lifting device further includes an electromagnetic clutch disposed between the driving member and the deceleration structure. The electromagnetic clutch has a transmission state and a disengaged state. When the lifted object freely falls and the rotational speed of the drive shaft of the driving member is greater than or equal to a preset rotational speed, the controller controls the electromagnetic clutch to switch from the transmission state to the disengaged state.

[0010] Further, the driving member includes a driving body and a rotational speed sensor disposed on the driving body. The drive shaft is connected to the driving body. The rotational speed sensor is in signal connection with the controller, and the rotational speed sensor can measure the rotational speed of the drive shaft.

[0011] Further, both the deceleration structure and the electromagnetic clutch are disposed within the drum.

[0012] According to another aspect of the present invention, a crane is provided, including a crane body and a lifting device disposed on the crane body. The lifting device is the above-mentioned lifting device. The crane further includes a lifting arm hingedly connected to the crane body. The first end of the cable of the lifting device is wound around the drum, and the middle portion of the cable is slidably disposed on the lifting arm.

[0013] Further, the crane further includes a lifting assembly. The lifting assembly includes a connecting shaft and a first pulley and a second pulley disposed on the connecting shaft. The middle portion of the cable surrounds the first pulley and the second pulley. The second end of the cable is connected to the lifting arm. The connection point of the lifted object and the connecting shaft is located between the first pulley and the second pulley.

[0014] Further, a third pulley and a fourth pulley are disposed on the lifting arm. The third pulley and the fourth pulley are coaxially disposed. The first pulley is located below the third pulley, and the second pulley is located below the fourth pulley. The cable sequentially passes through the third pulley, the first pulley, the fourth pulley, the second pulley and is connected to the lifting arm. The connection point of the cable and the lifting arm is located on the side of the fourth pulley away from the third pulley.

[0015] Further, the tension sensing member of the lifting device is arranged on the cable near the second end of the cable.

[0016] Applying the technical solution of the present utility model, the lifting device includes a mounting seat, a hoisting mechanism, a driving member, a speed reduction structure, a braking structure, a tension sensing member and a controller. The hoisting mechanism includes a drum rotatably arranged on the mounting seat and a cable wound around the drum, and the cable is connected to the lifted member. The driving member is in driving cooperation with the drum. The speed reduction structure is arranged between the driving member and the drum. A braking structure is further arranged on the mounting seat. The braking structure has a braking position and an avoidance position. When the braking structure is in the braking position, the braking structure is in braking cooperation with the speed reduction structure. When the braking structure is in the avoidance position, the braking structure avoids the speed reduction structure. A tension sensing member is arranged on the cable. The controller is in signal connection with the driving member, the braking structure and the tension sensing member. When the lifted member is in the free fall working mode and the measured value of the tension sensing member is less than or equal to the preset force value, the controller controls the braking structure to switch from the avoidance position to the braking position. Through the above settings, the driving member can drive the drum to rotate, and then the drum can drive the cable to move, so that the cable can lift the lifted member. The speed reduction structure can reduce the rotation speed transmitted from the driving member to the drum and avoid the drum rotating too fast. The tension sensing member can measure the tension received by the cable, which is convenient for judging whether there is a lifted member on the cable or the lifted member has fallen to the placement platform according to the measurement signal of the tension sensing member. The controller can receive the measurement signal of the tension sensing member, and then can judge whether the lifted member in the free fall working mode has moved to the placement platform according to the measurement signal of the tension sensing member. When the lifted member moves to the placement platform, the controller controls the braking structure to be in the braking position so that the speed reduction structure stops rotating, and then the drum connected to the speed reduction structure stops rotating. In this way, when manually controlling the drum, it is impossible to accurately control the timing of the drum stopping rotation. Furthermore, when the lifted member has not moved to the placement platform, the drum stops rotating, and due to the inertia of the lifted member, it impacts the drum, resulting in potential safety hazards. It also avoids the over-release of the cable caused by the cable still being released after the lifted member moves to the placement platform. Therefore, the technical solution of the present application effectively solves the problem in the prior art that it is impossible to accurately control the timing of the drum stopping rotation when the lifted member freely falls. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The specification drawings forming a part of the present application are used to provide a further understanding of the present utility model. The schematic embodiments of the present utility model and their descriptions are used to explain the present utility model and do not constitute an improper limitation to the present utility model. In the drawings:

[0018] Figure 1 The schematic diagram of the principle of the embodiment of the lifting device according to the present utility model is shown;

[0019] Figure 2 shows a Figure 1 schematic cross-sectional view of the drum of the hoisting device;

[0020] Figure 3 shows a Figure 1 control schematic diagram of the hoisting device;

[0021] Figure 4 shows a front view schematic diagram of an embodiment of a crane according to the present invention.

[0022] Among them, the above-mentioned drawings include the following reference numerals:

[0023] 1, the lifted object; 10, the mounting seat; 20, the hoisting mechanism; 21, the drum; 22, the rope; 30, the driving member; 31, the driving body; 32, the rotational speed sensor; 40, the deceleration structure; 50, the braking structure; 51, the two-position three-way solenoid valve; 52, the brake; 521, the cylinder block; 5211, the rodless cavity; 522, the brake rod; 523, the reset member; 60, the tension sensing member; 70, the controller; 80, the electromagnetic clutch; 100, the crane body; 110, the lifting arm; 111, the third pulley; 112, the fourth pulley; 120, the lifting assembly; 121, the connecting shaft; 122, the first pulley; 123, the second pulley. Detailed implementation manners

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way restrictive of the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0025] It should be noted that the terms used here are only for describing the specific implementation manners and are not intended to limit the exemplary implementation manners according to the present application. As used here, unless otherwise clearly specified in the context, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "comprise" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0026] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present utility model. At the same time, it should be understood that for the sake of description, the dimensions of the various parts shown in the drawings are not drawn in accordance with actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the specification. In all the examples shown and discussed here, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, further discussion thereof is not required in subsequent drawings.

[0027] As Figure 1 and Figure 3 shown, the hoisting device of this embodiment includes: a mounting seat 10, a hoisting mechanism 20, a driving member 30, a speed reduction structure 40, a braking structure 50, a tensile sensing member 60, and a controller 70. The hoisting mechanism 20 includes a drum 21 and a cable 22. The drum 21 is rotatably arranged on the mounting seat 10, the cable 22 is wound around the drum 21, and the cable 22 is connected to the lifted member 1. The driving member 30 is drivingly engaged with the drum 21. The speed reduction structure 40 is arranged between the driving member 30 and the drum 21. The braking structure 50 is arranged on the mounting seat 10. The braking structure 50 has a braking position and an avoidance position. When the braking structure 50 is in the braking position, the braking structure 50 is brakingly engaged with the speed reduction structure 40. The tensile sensing member 60 is arranged on the cable 22. The controller 70 is in signal connection with the driving member 30, the braking structure 50, and the tensile sensing member 60. Among them, when the lifted member 1 is in the free-fall working mode and the measured value of the tensile sensing member 60 is less than or equal to a preset force value, the controller 70 controls the braking structure 50 to switch from the avoidance position to the braking position.

[0028] Applying the technical solution of this embodiment, the hoisting device includes a mounting base 10, a hoisting mechanism 20, a driving member 30, a speed reduction structure 40, a braking structure 50, a tension sensing member 60, and a controller 70. The hoisting mechanism 20 includes a drum 21 rotatably arranged on the mounting base 10 and a cable 22 wound around the drum. The cable 22 is connected to the lifted member 1. The driving member 30 is drivingly engaged with the drum 21. The speed reduction structure 40 is arranged between the driving member 30 and the drum 21. A braking structure 50 is further arranged on the mounting base 10. The braking structure 50 has a braking position and an avoidance position. When the braking structure 50 is in the braking position, the braking structure 50 is in braking cooperation with the speed reduction structure 40. When the braking structure 50 is in the avoidance position, the braking structure 50 avoids the speed reduction structure 40. A tension sensing member 60 is arranged on the cable 22. The controller 70 is in signal connection with the driving member 30, the braking structure 50, and the tension sensing member 60. When the lifted member 1 is in the free-fall working mode and the measured value of the tension sensing member 60 is less than or equal to a preset force value, the controller 70 controls the braking structure 50 to switch from the avoidance position to the braking position. Through the above settings, the driving member 30 can drive the drum 21 to rotate, and then the drum 21 can drive the cable 22 to move, so that the cable 22 can lift the lifted member 1. The speed reduction structure 40 can reduce the rotational speed transmitted from the driving member 30 to the drum 21, avoiding the drum 21 from rotating too fast. The tension sensing member 60 can measure the tension received by the cable 22, facilitating the judgment of whether there is a lifted member 1 on the cable 22 or the lifted member 1 has fallen to the placement platform according to the measurement signal of the tension sensing member 60. The controller 70 can receive the measurement signal of the tension sensing member 60, and then can judge whether the lifted member 1 in the free-fall working mode has moved to the placement platform according to the measurement signal of the tension sensing member 60. After the lifted member 1 moves to the placement platform, the controller 70 controls the braking structure 50 to be in the braking position, so that the speed reduction structure 40 stops rotating, and thus the drum 21 connected to the speed reduction structure 40 stops rotating. This avoids the situation where when manually controlling the drum 21, the timing of stopping the rotation of the drum 21 cannot be accurately controlled. Furthermore, it avoids the impact on the drum 21 caused by the inertia of the lifted member 1 when the drum 21 stops rotating before the lifted member 1 moves to the placement platform, resulting in potential safety hazards. It also avoids the over-release of the cable 22 caused by the cable 22 still being released after the lifted member 1 moves to the placement platform. Therefore, the technical solution of this embodiment effectively solves the problem in the prior art that the timing of accurately controlling the drum to stop rotating cannot be achieved.

[0029] The hoisting device of this embodiment can be applied to a crane or a gantry crane. The lifted member has a weight.

[0030] Of course, in other embodiments, the brake structure 50 may also directly brake and cooperate with the reel 21. Specifically, the brake structure 50 has a brake position for braking and cooperating with the reel 21 and a avoidance position for avoiding the reel 21. At this time, when the brake structure 50 is in the brake position, the brake structure 50 abuts and cooperates with the inner wall of the reel 21, or the brake structure 50 abuts and cooperates with the end of the reel 21.

[0031] It should be noted that the rope 22 is a steel wire rope. The tension sensor 60 is a tension sensor. The deceleration structure 40 is a reducer. In this embodiment, the preset force value is 0. The placement platform can be the ground, the floor of the carriage, or other transfer platforms.

[0032] In the prior art, two wire rope drums need to be equipped with two sets of starting devices and braking devices, and the synchronization problem of the two drums needs to be solved (adding mechanical devices or electronic control devices). During the free lowering process, the motor needs to be arranged separately from the reducer and other devices or arranged as a whole, and the drum speed is slow, which reduces the working efficiency. In this embodiment, one drum 21 is provided for easy control.

[0033] like Figure 1 As shown, in this embodiment, the brake structure 50 has a braking position for braking with the deceleration structure 40 and a evasion position for avoiding the deceleration structure 40. The brake structure 50 includes a two-position three-way solenoid valve 51 and a brake 52 connected to the two-position three-way solenoid valve 51. When the brake structure 50 is switched from the evasion position to the braking position, the driving fluid enters the brake 52 through the two-position three-way solenoid valve 51, so that the brake 52 is in braking cooperation with the deceleration structure 40. Through the above-mentioned setting, when the controller 70 controls the switching of the two-position three-way solenoid valve 51, it can stop the driving fluid or make the fluid pass through the two-position three-way solenoid valve 51. When the driving fluid flows through the two-position three-way solenoid valve 51, it can drive the brake 52, so that the brake 52 is in braking cooperation with the deceleration structure 40.

[0034] The driving fluid is hydraulic oil, or of course, compressed gas.

[0035] like Figure 1As shown, in this embodiment, the brake 52 includes a cylinder 521, a brake rod 522 inserted in the cylinder 521, and a reset member 523 disposed between the brake rod 522 and the cylinder 521. The rodless chamber 5211 of the cylinder 521 is connected to the two-position three-way solenoid valve 51. When the brake structure 50 is switched from the avoidance position to the braking position, the driving fluid enters the rodless chamber 5211 through the two-position three-way solenoid valve 51, and squeezes the brake rod 522 to move toward the deceleration structure 40 to brake the deceleration structure 40. The driving fluid can enter the rodless chamber 5211, and then can push the brake rod 522 to move toward the deceleration structure 40, so that the brake rod 522 can abut the deceleration structure 40, realize the braking of the deceleration structure 40, and then realize the braking of the reel 21. When the brake rod 522 moves toward the deceleration structure 40 , it can squeeze the reset member 523 , so that after the driving fluid flows from the rodless chamber 5211 to the two-position three-way solenoid valve 51 , the reset member 523 can apply a reset force to the brake rod 522 to move the brake rod 522 away from the deceleration structure 40 .

[0036] It should be noted that the reset member 523 is a spring. The brake rod 522 is in braking cooperation with the output shaft of the reducer, and the output shaft of the reducer is connected to the reel 21 .

[0037] The two-position three-way solenoid valve 51 has an inlet, a first outlet and a second outlet. When the brake structure 50 is in the braking position, the inlet is connected to the first outlet, the driving fluid enters the two-position three-way solenoid valve 51 from the inlet, and enters the brake 52 through the first outlet, and the brake rod 522 moves toward the deceleration structure 40. When the brake structure 50 is switched from the braking position to the avoidance position, the first outlet is connected to the second outlet, the driving fluid moves from the brake 52 to the first outlet, and moves to the second outlet through the first outlet, and then flows out from the second outlet, and the brake rod 522 can move in a direction away from the deceleration structure 40.

[0038] like Figure 1 and Figure 2As shown in the figure, in this embodiment, the lifting device further includes an electromagnetic clutch 80 disposed between the driving member 30 and the reduction structure 40. The electromagnetic clutch 80 has a transmission state and a disengaged state. When the lifted object 1 freely falls and the rotational speed of the drive shaft of the driving member 30 is greater than or equal to a preset rotational speed, the controller 70 controls the electromagnetic clutch 80 to switch from the transmission state to the disengaged state. When the lifted object 1 is in the free-fall working mode, the lifted object 1 drives the cable 22 to move. The movement of the cable 22 drives the drum 21 to rotate. The rotation of the drum 21 drives the reduction structure 40 to rotate. The reduction structure 40 drives the driving member 30 to move. The controller 70 can control the electromagnetic clutch 80 to switch from the transmission state to the disengaged state according to the rotational speed of the drive shaft of the driving member 30, avoiding the rotational speed of the drive shaft of the driving member 30 exceeding the preset rotational speed and causing damage to the driving member 30, thus having high safety performance.

[0039] It should be noted that the driving member 30 includes a fixed-displacement motor. The drive shaft is disposed on the fixed-displacement motor. The preset rotational speed can be the rated rotational speed of the driving member. Of course, it can also be any value between 95% and 100% of the rated rotational speed of the driving member.

[0040] When the lifted object 1 freely falls, it will drive the drum 21 to rotate in reverse. The driving member 30 does not actively work at this time, but the drum 21 will drive it to work passively through the reduction structure 40 and the electromagnetic clutch 80, which will cause the problem of overspeed of the drive shaft of the driving member 30 during rotation. Assume a free-fall mechanism, the lifting height h of the lifted heavy object is 1000 mm, the reduction ratio of the reduction mechanism is 80, the rated rotational speed n1 of the fixed-displacement motor is 3000 r / s, and the radius r of the drum is 360 mm. Since the lifted object 1 makes a free-fall motion with an initial velocity of zero, according to Newton's law, the time t for the object to reach the ground is: When the object reaches the ground, the speed v reaches the maximum. At this time, the rotational speed n2 of the drum 21 also reaches the maximum, and the magnitude of the rotational speed n2 is: Assume that the fixed-displacement motor and the drum rotate at high speed together. Then the rotational speed n3 of the fixed-displacement motor at this time = n2 × 80 = 59440 r / s. At this time, the rotational speed of the fixed-displacement motor is much greater than its rated rotational speed. Therefore, it is necessary for the electromagnetic clutch 80 to disconnect from the reduction structure 40 after receiving the signal that the drive shaft of the driving member 30 reaches the rated rotational speed to prevent damage to the driving member 30.

[0041] Such as Figure 2 and Figure 3As shown, in this embodiment, the driving member 30 includes a driving body 31 and a rotational speed sensor 32 provided on the driving body 31. The driving shaft is connected to the driving body 31, and the rotational speed sensor 32 is in signal connection with the controller 70. The rotational speed sensor 32 can measure the rotational speed of the driving shaft. The rotational speed sensor 32 can measure the rotational speed of the driving shaft and transmit the rotational speed signal to the controller 70.

[0042] As Figure 2 shown, in this embodiment, the deceleration structure 40 and the electromagnetic clutch 80 are both provided inside the drum 21. The drum 21 can protect the deceleration structure 40 and the electromagnetic clutch 80, and also make the overall structure of the hoisting device more regular. It also simplifies the entire hoisting device to the greatest extent, increases the flexibility and operability of the hoisting device itself, and reduces the manufacturing and maintenance costs.

[0043] The controller 70 has a first working state and a second working state. When the controller 70 is in the first working state, the cable 22 can lift the lifted object 1, or the lifted object 1 can be suspended in the air, or the cable 22 can drive the lifted object 1 to move in the air. When the controller 70 is in the second working state, the lifted object 1 is in the free-fall working mode.

[0044] As Figure 3 shown, the positive pole of the power supply is connected to the controller 70 through the first connecting wire, and the negative pole of the power supply is connected to the controller 70 through the second connecting wire, so that the power supply can continuously supply power to the controller 70.

[0045] As Figure 3 shown, the tension sensing member 60 is provided on the third connecting wire. The third connecting wire is connected between the positive pole of the power supply and the controller 70. When current flows, it flows from the positive pole of the power supply to the third connecting wire, then to the controller 70, then to the second connecting wire, and then to the negative pole of the power supply.

[0046] As Figure 3 shown, the rotational speed sensor 32 is provided on the fourth connecting wire. The fourth connecting wire is between the positive pole of the power supply and the controller 70. When current flows, it flows from the positive pole of the power supply to the fourth connecting wire, then to the controller 70, then to the second connecting wire, and then to the negative pole of the power supply.

[0047] As Figure 3 shown, the two-position three-way solenoid valve 51 is provided on the fifth connecting wire. The fifth connecting wire is between the negative pole of the power supply and the controller 70. When current flows, it flows from the controller 70 to the fifth connecting wire, and then to the negative pole of the power supply.

[0048] As Figure 3As shown, the electromagnetic clutch 80 is arranged on the sixth connecting line, and the sixth connecting line is between the negative pole of the power supply and the controller 70. When the current flows, it flows from the controller 70 to the sixth connecting line, and then flows to the negative pole of the power supply.

[0049] like Figure 3 As shown, the switch button is arranged on the seventh connection line, and the seventh connection line is connected between the positive electrode of the power supply and the controller 70. When the current flows, it flows from the positive electrode of the power supply to the switch button, then flows to the controller 70, finally flows to the second connection line, and then flows to the negative electrode of the power supply. When the switch button is pressed, the controller 70 can switch from the first working state to the second working state.

[0050] like Figure 3 As shown, the emergency stop button is arranged on the seventh connection line, and the emergency stop button is arranged between the switch button and the controller. When the current flows, it flows from the positive electrode of the power supply to the switch button, then flows to the emergency stop button, then flows to the controller 70, and finally flows to the second connection line, and then flows to the negative electrode of the power supply. The emergency stop button can ensure that when an unexpected situation occurs, the circuit is cut off in time to ensure that the reel 21 stops rotating.

[0051] When the switch button is turned on, the controller switches to the second working state. At this time, when the rope 22 lifts the weight, the tension sensor 60 returns the weight lifting signal, and the controller 70 outputs an electrical signal after receiving the weight lifting signal. The two-position three-way solenoid valve 51 is energized, so that the brake rod 522 is disengaged from the deceleration structure 40, the drum 21 rotates, and the rope 22 is freely lowered. At the same time, the speed sensor 32 built into the driving member 30 transmits the speed signal to the controller 70 in real time. When the preset rotation speed is reached, the electromagnetic clutch 80 is energized, and the driving member 30 is disengaged from the deceleration structure 40 in the drum 21. When the hoisted object 1 falls to the ground, the tension sensor 60 does not return the weight lifting signal to the controller 70, and the two-position three-way solenoid valve 51 cannot receive the electrical signal output by the controller 70 and loses power, so that the brake rod 522 contacts the deceleration structure 40, the drum 21 is braked immediately, and the rope 22 stops lowering. When the switch button is not turned on, the controller is in the first working state, at this time, the two-position three-way solenoid valve 51 is not powered, the brake structure 50 is in the braking state, and the electromagnetic clutch 80 is not powered, and the drive member 30 and the deceleration structure 40 are in the connection state. In the process of lowering the weight of the lifting device, the start and close of the brake structure 50 are automatically carried out according to the lifting signal returned by the tension sensor 60, which can achieve accurate and timely control and prevent problems such as unsafe human control and over-release of the rope.

[0052] The load signal is transmitted to the controller 70 through the third connecting line, and the rotational speed signal is transmitted to the controller 70 through the fourth connecting line. When the controller 70 controls the two-position three-way solenoid valve 51, the controller 70 outputs an electrical signal and transmits it to the two-position three-way solenoid valve 51 through the fifth connecting line. When the controller 70 controls the electromagnetic clutch 80, the controller 70 outputs an electrical signal and transmits it to the electromagnetic clutch 80 through the sixth connecting line.

[0053] As Figure 3 shown, in the figure, SP represents the load signal, and SR represents the rotational speed signal.

[0054] The load signal is the measurement signal of the tension sensing member 60.

[0055] When the hoisting device of this embodiment lowers the hoisted item 1, it adopts the form of free fall. This method utilizes the gravity of the hoisted item 1 when the hoisted item 1 is lowered, and the hoisted item 1 has a fast falling speed, while saving a large amount of energy consumption. The hoisting device is equipped with a braking structure 50, which uses the tension sensing member 60 to collect and feedback the load signal, and accurately controls the start and stop time of the braking structure 50. A single drum 21 is used to wind the steel wire rope. Compared with the double-drum form, only one driving member 30 and one braking structure 50 need to be set, and there is no need to install a synchronization mechanism, which simplifies the overall structure and also saves installation space. The hoisting device is equipped with an electromagnetic clutch 80, which can ensure the high-speed rotation of the drum 21 when the hoisted item 1 freely falls and will not exceed the limit rotational speed and damage the driving member 30.

[0056] When the hoisted item 1 is in the free fall working mode, the driving member 30 does not work, and the hoisted item 1 makes a free fall movement downward. After reaching the placement platform, the braking structure 50 starts to work and the lowering stops. When the hoisting device performs the hoisting action, the driving member 30 operates to drive the hoisted item 1 to rise. When it reaches the set height position, the hoisting device stops working and the hoisting ends.

[0057] As Figure 4 shown, the crane of this embodiment includes a crane body 100 and a hoisting device provided on the crane body 100. The hoisting device is the above-mentioned hoisting device. The crane further includes a hoisting arm 110 hinged to the crane body 100. The first end of the cable 22 of the hoisting device is wound around the drum 21, and the middle part of the cable 22 is slidably arranged on the hoisting arm 110. When the above-mentioned hoisting device is in use, the controller 70 can judge whether the hoisted item 1 has moved to the placement platform through the measurement signal of the tension sensing member 60. Furthermore, after the hoisted item 1 moves to the placement platform, the controller 70 can control the braking structure 50 to switch to the braking position to prevent the drum 21 from rotating again.

[0058] The crane of this embodiment is applied to railways. The crane body 100 can provide driving fluid. A rotating seat is arranged on the crane body 100, and the lifting arm 110 and the lifting device are connected to the rotating seat, and the rotating seat can drive the lifting arm 110 and the lifting device to rotate simultaneously.

[0059] As Figure 1 and Figure 4 shown, in this embodiment, the crane further includes a lifting assembly 120. The lifting assembly 120 includes a connecting shaft 121 and a first pulley 122 and a second pulley 123 arranged on the connecting shaft 121. The middle part of the cable 22 is wound around the first pulley 122 and the second pulley 123. The second end of the cable 22 is connected to the lifting arm 110, and the connection point of the lifted object 1 and the connecting shaft 121 is located between the first pulley 122 and the second pulley 123. When the cable 22 moves, it can slide on the first pulley 122 and the second pulley 123, and then can drive the first pulley 122 and the second pulley 123 to move, so that the first pulley 122 and the second pulley 123 can drive the connecting shaft 121 to move, realizing the lifting of the lifted object 1. The connection point of the lifted object 1 and the connecting shaft 121 is located between the first pulley 122 and the second pulley 123, making the force on the lifting assembly 120 more uniform and ensuring the stable operation of the lifting assembly 120.

[0060] The lifting assembly 120 further includes a hook, and the lifted object 1 is connected to the hook.

[0061] As Figure 1 and Figure 4 shown, in this embodiment, a third pulley 111 and a fourth pulley 112 are arranged on the lifting arm 110. The third pulley 111 and the fourth pulley 112 are coaxially arranged. The first pulley 122 is located below the third pulley 111, and the second pulley 123 is located below the fourth pulley 112. The cable 22 passes through the third pulley 111, the first pulley 122, the fourth pulley 112, the second pulley 123 in sequence and is connected to the lifting arm 110. The connection point of the cable 22 and the lifting arm 110 is located on the side of the fourth pulley 112 away from the third pulley 111. The cable 22 can slide on the third pulley 111, the first pulley 122, the fourth pulley 112 and the second pulley 123, and then the cable 22 can drive the lifting assembly 120 to lift and lower through the first pulley 122 and the second pulley 123. By arranging the first pulley 122, the second pulley 123, the third pulley 111 and the fourth pulley 112, a smaller driving force can be applied to the drum 21 by the driving member 30 to realize the lifting of the lifted object 1.

[0062] The first pulley 122 and the second pulley 123 form a movable pulley block, and the third pulley 111 and the fourth pulley 112 form a fixed pulley block. The fixed pulley block and the movable pulley block form a guiding pulley block. The fixed pulley block is fixed on the lifting arm 110, and the movable pulley block is suspended in the air.

[0063] As Figure 1 and Figure 4 shown, in this embodiment, the tension sensing member 60 of the hoisting device is arranged on the cable 22 at a position close to the second end of the cable 22. Through the above arrangement, it can be ensured that the tension sensing member 60 is not affected by the sliding of the cable 22 between the third pulley 111, the first pulley 122, the fourth pulley 112 and the second pulley 123, and thus the tension of the cable 22 can be continuously measured.

[0064] The tension sensing member 60 in this embodiment detects the tension of the cable 22. Of course, in other embodiments, the tension sensing member 60 can detect the tension of the luffing wire rope, or, without setting the tension sensing member 60, a pressure sensor is set to detect the pressure of the luffing cylinder, and the cable tension is obtained by conversion.

[0065] The hoisting device is arranged at the rear of the crane body 100. The drum 21 in this embodiment is a single drum, which greatly saves the installation space compared with a double drum. When the electromagnetic clutch 80 drives the drive shaft of the driving member 30 to reach a preset rotational speed, the driving member 30 is disengaged from the reduction structure 40 to ensure the safety during its actual operation. The tension sensing member 60 and the lifting assembly 120 are arranged in front of the crane body 100, which is convenient for receiving the signal of whether the lifted item 1 has landed more quickly and accurately.

[0066] When the lifted item 1 descends rapidly, the two-way three-way solenoid valve 51 in the hoisting device is energized, the brake 52 has no pressure oil input and is in the release position, the drum 21 has no braking force, the cable 22 is lowered freely, and the lifted item 1 can descend freely. When the lifted item 1 lands on the ground, the measurement signal of the tension sensing member 60 located directly above the lifted item 1 changes, and the controller 70 controls the two-way three-way solenoid valve 51 to lose power rapidly. The pressure oil at the P port (i.e., the inlet) enters the cylinder body 521 through the two-way three-way solenoid valve 51, the brake 52 has pressure oil input and is in the braking position, the drum 21 is braked and stops rotating, and the cable 22 stops lowering. During the free lowering process of the lifted item 1, the rotational speed sensor 32 inside the driving member 30 feeds back the rotational speed signal to the controller 70 in real time. When the preset rotational speed is not reached, the drive shaft of the driving member 30 rotates together with the reduction structure 40. When the preset rotational speed is reached, the two are immediately disengaged to prevent the driving member 30 from being damaged and affecting the normal operation.

[0067] The hoisting device in this embodiment has the following advantages:

[0068] 1. The single-drum hoisting device greatly saves the installation space, reduces the manufacturing and maintenance costs, increases the overall flexibility and operability of the hoisting device. The electromagnetic clutch 80 can make the driving member 30 rotate at a high speed without exceeding the limited speed and damaging the driving member 30.

[0069] 2. For a crane using a hoisting device with a free-fall working mode, after the lifted item 1 lands, it can accurately grasp the braking timing, and the hook automatically hovers in the air, solving the problems in the prior art that it is difficult to ensure safe operation and easy to cause over-release of the wire rope.

[0070] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom", etc. is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description. Without contrary description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the protection scope of the present invention; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0071] For the convenience of description, spatial relative terms such as "above...", "above...", "on the upper surface of...", "above" etc. can be used here to describe the spatial positional relationship between a device or feature shown in the figure and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation other than the orientation described in the figure for the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "beneath other devices or structures" afterwards. Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding explanations are made for the spatial relative descriptions used here.

[0072] In addition, it should be noted that using words such as "first", "second" etc. to limit the components is only for the convenience of differentiating the corresponding components. Without additional declaration, the above words have no special meaning. Therefore, it should not be construed as a limitation on the protection scope of the present invention.

[0073] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. For those skilled in the art, various modifications and variations can be made to the present utility model. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A lifting device, characterized in that, Comprising: Mounting base (10); Hoisting mechanism (20), the hoisting mechanism (20) includes a drum (21) and a cable (22), the drum (21) is rotatably arranged on the mounting base (10), the cable (22) is wound around the drum (21), and the cable (22) is connected to the lifted object (1); Driving member (30), the driving member (30) is in driving cooperation with the drum (21); Deceleration structure (40), the deceleration structure (40) is arranged between the driving member (30) and the drum (21); Braking structure (50), arranged on the mounting base (10), the braking structure (50) has a braking position and an avoidance position, when the braking structure (50) is in the braking position, the braking structure (50) is in braking cooperation with the deceleration structure (40), or the braking structure (50) is in braking cooperation with the drum (21); Tensile sensing member (60), the tensile sensing member (60) is arranged on the cable (22); Controller (70), the controller (70) is in signal connection with the driving member (30), the braking structure (50) and the tensile sensing member (60); Wherein, when the lifted object (1) is in the free-fall working mode and the measured value of the tensile sensing member (60) is less than or equal to the preset force value, the controller (70) controls the braking structure (50) to switch from the avoidance position to the braking position.

2. The hoisting device according to claim 1, characterized in that, The braking structure (50) has a braking position for braking cooperation with the deceleration structure (40) and an avoidance position for avoiding the deceleration structure (40). The braking structure (50) includes a two-position three-way solenoid valve (51) and a brake (52) connected to the two-position three-way solenoid valve (51). When the braking structure (50) switches from the avoidance position to the braking position, the driving fluid enters the brake (52) through the two-position three-way solenoid valve (51), so that the brake (52) is in braking cooperation with the deceleration structure (40).

3. The hoisting device according to claim 2, characterized in that, The brake (52) includes a cylinder block (521), a brake rod (522) inserted into the cylinder block (521), and a reset member (523) arranged between the brake rod (522) and the cylinder block (521). The rodless cavity (5211) of the cylinder block (521) is communicated with the two-position three-way solenoid valve (51). When the braking structure (50) switches from the avoidance position to the braking position, the driving fluid enters the rodless cavity (5211) through the two-position three-way solenoid valve (51) and presses the brake rod (522) to move towards the deceleration structure (40) to brake the deceleration structure (40).

4. The hoisting device according to any one of claims 1 to 3, characterized in that, The lifting device further includes an electromagnetic clutch (80) disposed between the driving member (30) and the speed reduction structure (40). The electromagnetic clutch (80) has a transmission state and a disengaged state. When the lifted member (1) freely falls and the rotational speed of the drive shaft of the driving member (30) is greater than or equal to a preset rotational speed, the controller (70) controls the electromagnetic clutch (80) to switch from the transmission state to the disengaged state.

5. The hoisting device according to claim 4, characterized in that, The driving member (30) includes a driving body (31) and a rotational speed sensor (32) disposed on the driving body (31). The drive shaft is connected to the driving body (31). The rotational speed sensor (32) is in signal connection with the controller (70), and the rotational speed sensor (32) can measure the rotational speed of the drive shaft.

6. The hoisting device according to claim 4, characterized in that, Both the speed reduction structure (40) and the electromagnetic clutch (80) are disposed within the drum (21).

7. A crane, comprising a crane body (100) and a hoisting device provided on the crane body (100), characterized in that, The lifting device is the lifting device according to any one of claims 1 to 6. The crane further includes a lifting arm (110) hingedly connected to the crane body (100). The first end of the cable (22) of the lifting device is wound around the drum (21), and the middle portion of the cable (22) is slidably disposed on the lifting arm (110).

8. The crane according to claim 7, characterized in that, The crane further includes a lifting assembly (120). The lifting assembly (120) includes a connecting shaft (121) and a first pulley (122) and a second pulley (123) disposed on the connecting shaft (121). The middle portion of the cable (22) is wound around the first pulley (122) and the second pulley (123). The second end of the cable (22) is connected to the lifting arm (110). The connection point of the lifted member (1) and the connecting shaft (121) is located between the first pulley (122) and the second pulley (123).

9. The crane according to claim 8, wherein, A third pulley (111) and a fourth pulley (112) are disposed on the lifting arm (110). The third pulley (111) and the fourth pulley (112) are coaxially disposed. The first pulley (122) is located below the third pulley (111), and the second pulley (123) is located below the fourth pulley (112). The cable (22) sequentially passes through the third pulley (111), the first pulley (122), the fourth pulley (112), the second pulley (123) and is connected to the lifting arm (110). The connection point of the cable (22) and the lifting arm (110) is located on the side of the fourth pulley (112) away from the third pulley (111).

10. The crane according to claim 8 or 9, characterized in that, The tension sensing member (60) of the lifting device is disposed on the cable (22) at a position close to the second end of the cable (22).

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