CN204549856U - Lifting limit control system, lifting mechanism and hoisting crane - Google Patents

Abstract

The utility model relates to a lifting limit control system, a lifting mechanism and a crane. The lifting limit control system includes a photoelectric rotation detection device and a limit controller. The detection signal sent by the photoelectric rotation detection device is sent to the limit controller; the photoelectric rotation detection device has a A rotating disc for detection which is assembled by a shaft and a stationary bracket for detection with a photoelectric switch installed facing the rotating disc; the photoelectric rotation detection device has at least one set of detection units, each set of detection units is composed of An eccentric hole arranged on the disk and a group of photoelectric switches arranged on the stationary support are formed. Each photoelectric switch is distributed on the arc line corresponding to the above-mentioned eccentric hole, and the photoelectric switch is used to send the detection signal. The photoelectric rotation detection device of the utility model reduces the size of the whole device, makes the device easy to install, and the lifting limit control system operates reliably.

Description

Lifting limit control system, lifting mechanism and crane

technical field

The utility model relates to a lifting and limiting control system, a lifting mechanism and a crane, in particular to a lifting mechanism with a lifting and limiting function and a crane using the lifting mechanism with the lifting and limiting function.

Background technique

In cranes and some lifting mechanisms, it is necessary to forcibly stop the lifting action at the upper and lower limit positions, which requires a lifting limit control system. The lifting limit control system refers to that when the lifting hook, platform or cage is raised to the limit position or lowered to the limit position, the lifting limit control system sends a signal to the control unit of the drive motor so that it no longer receives the signal. Forward rotation or reverse rotation signal, the mechanism such as the hook that has reached the limit position will not continue to rise or fall, and a kind of operation safety protection control system that makes the brake lock.

There are mechanical control and electronic control in the existing mature lifting limit control system.

There are two main types of mechanical controls. One is to realize the work of the contactor through the left and right sliding of the rope guide on the reel to drive the pull rod, or the cross slider coupling at the end of the reel to drive the nut on the screw to move axially in series to realize the work of the contactor, thereby controlling the lifting The other is to use the heavy hammer to control the work of the travel switch. When the hook pulley touches the heavy hammer, the travel switch works to realize the height control. These products often lose their function due to mechanical wear and tear to reduce accuracy or mechanical damage.

Electronic controls are mainly encoders (incremental encoders and absolute encoders), and photoelectric rotation detection devices that use the same principle as encoders. The main principle of the photoelectric rotation detection device is to indirectly measure the height of the hook's rise and fall by detecting the angle of rotation of the transmission equipment such as the winch. The electronic control system is an embedded system, which is mainly composed of a photoelectric rotation detection device and a limit controller. The control output of the limit controller is connected with the start-stop controller of the drive motor and the brake mechanism controller. The photoelectric rotation detection device is used to measure the information of rotation angle, number of circles, forward rotation or reverse rotation, and send the detected information to the limit controller. The limit controller performs cumulative calculation based on these information to calculate the actual altitude; and by comparing with the set altitude upper limit and lower limit, it is judged whether it is necessary to stop. The limit controller has a display screen for displaying the above information. The limit controller has a data input part for inputting set control quantities (such as height upper limit, lower limit value, pulley block ratio, reduction mechanism reduction ratio, etc.).

There are many specific structures of the encoder, but the most basic structure is a photoelectric code disc and a photoelectric switch (the photoelectric switch includes a light emitting unit corresponding to the photoelectric code disc, a light receiving unit, and a signal generating circuit for photoelectric conversion). Light-transmitting grids (or reticles capable of reflecting light) can be regularly arranged on the photoelectric code disc in the circumferential direction. When the photoelectric code disc rotates, the photoelectric switch generates pulse signals synchronous with the grid, so as to use these pulse signals to achieve measurement.

The problems with using encoders for winch lift limit control are:

1. There is a problem that fuzzy signals are easily generated during the starting and braking stages when using an encoder for measurement. This is because the crane is a heavy-duty equipment, and it will vibrate strongly during the starting and braking stages, making the boundary between multiple continuous pulse signals output by the encoder blurred, and it is impossible to accurately identify the lifting distance. The hook has actually traveled a certain distance, but the encoder does not count; or when braking, the encoder does not count after the hook starts to brake.

In addition, for the code disc with coated reticles, the vibration will cause the reticles to detach, and the long-term operation will also cause the reticles to age, and the dust pollution will also affect the detection results.

2. The drive motor drives the reel through the deceleration mechanism, and the reel winds or releases the rope to realize the lifting or lowering of hooks and other mechanisms; wherein, the encoder is installed on the low-speed rotating shaft decelerated by the deceleration mechanism. Since the purpose of the measurement is to obtain the length of the rope rising and falling, the length of the rope rising and falling corresponding to one rotation of the low-speed shaft is determined (related to the diameter of the drum and the magnification of the hook), so the accuracy of the measurement depends on the above grid The interval angle between (reticle lines), the larger the interval angle, the lower the measurement accuracy, and the smaller the interval angle, the higher the measurement accuracy.

Improving the measurement accuracy can improve the accuracy of the lifting height control, so as to avoid the overrun when the upper or lower limit is reached during the ascent or descent phase.

At present, in order to improve the measurement accuracy, so that it can improve the position accuracy of the start-stop height at the limit position, the prior art focuses on reducing the interval angle between the grids by increasing the number of grids. However, without increasing the size of the photoelectric code disc, due to the limitation of the area of the photoelectric code disc and the limitation of the resolution of the sensor, the number of grids that can be increased is limited, that is to say, the measurement accuracy is also limited. If the size of the photoelectric code disc is increased, although the number of grids can be increased, the volume of the detection equipment will also increase accordingly, and the too large volume is not suitable for on-site installation at all, so increasing the size of the code disc is also limited by the installation space of the equipment .

To sum up, when the existing lifting mechanism is applied, not only the stability of the starting and braking phases is low, but the measurement error is large; the accuracy of the lifting measurement is also limited, resulting in the inability to achieve high-precision measurement and control. Therefore, hoisting and lifting control, especially in the starting and braking stages, the lifting limit and the accident of broken rope and falling objects often occur, which bring safety hazards to site construction or equipment use.

Utility model content

The purpose of the utility model is to provide a lifting limit control system to solve the problem that fuzzy signals are easy to be generated in the starting and braking stages and cannot be recognized. At the same time, the purpose of the utility model is also to provide a corresponding lifting mechanism and crane.

In order to achieve the above object, the lifting limit control system scheme of the utility model is as follows:

A lifting limit control system, including a photoelectric rotation detection device and a limit controller, the detection signal sent by the photoelectric rotation detection device is sent to the limit controller, and the control output of the limit controller is connected with the drive motor start-stop controller and the brake mechanism controller control connection; the photoelectric rotation detection device has a detected rotating disc for assembling with the corresponding shaft of the deceleration mechanism and a photoelectric switch installed facing the rotating disc. A stationary support for detection; the photoelectric rotation detection device has at least one set of detection units, each set of detection units is composed of an eccentric hole arranged on the rotating disc and a group of photoelectric switches arranged on the stationary support, each photoelectric switch is distributed in On the arc line corresponding to the eccentric hole, the photoelectric switch is used to send out the detection signal.

Further, the photoelectric rotation detection device has two or more detection units.

Further, the rotating disc is assembled on the high-speed shaft of the transmission mechanism.

Further, the three photoelectric switches of each set of detection units are evenly distributed on the corresponding arc lines.

The utility model also provides a lifting mechanism applying the above-mentioned lifting limit control system, including a deceleration mechanism and a reel mechanism. The deceleration mechanism is used to connect the drive motor through a high-speed shaft, and the deceleration mechanism is connected to the reel mechanism through a low-speed shaft. The high-speed shaft is equipped with a braking mechanism; the lifting mechanism also includes a lifting limit control system, and the lifting limit control system includes a photoelectric rotation detection device and a limit controller. The detection signal sent by the photoelectric rotation detection device is sent to the limit position controller, the control output of the limit controller is connected with the start-stop controller of the drive motor and the brake mechanism controller; Rotating disc and a stationary support for detection with a photoelectric switch facing the rotating disc; the photoelectric rotation detecting device has at least one set of detection units, and each set of detection units is formed by an eccentric set on the rotating disc. The hole and a group of photoelectric switches arranged on the stationary support are formed. Each photoelectric switch is distributed on the arc line corresponding to the above-mentioned eccentric hole, and the photoelectric switch is used to send the detection signal.

Further, the limit controller performs limit position power-off control on the driving motor and the brake through a contact of a relay.

Further, the photoelectric rotation detection device has two or more detection units.

Further, the rotating disc is assembled on the high-speed shaft of the transmission mechanism.

Further, the three photoelectric switches of each set of detection units are evenly distributed on the corresponding arc lines.

The utility model also provides a crane using the above-mentioned hoisting mechanism, including a hoisting mechanism composed of a drive motor, a deceleration mechanism and a reel mechanism. The reel mechanism is connected by transmission, and the high-speed shaft is equipped with a braking mechanism; the lifting mechanism also includes a lifting limit control system, which includes a photoelectric rotation detection device and a limit controller. The detection signal is sent to the limit controller, and the control output of the limit controller is connected with the drive motor start-stop controller and the brake mechanism controller; Assembled rotating disk for detection and a stationary support for detection with a photoelectric switch installed facing the rotating disk; the photoelectric rotation detection device has at least one set of detection units, and each set of detection units consists of a rotating disk It consists of an eccentric hole set on the top and a group of photoelectric switches set on the stationary support, each photoelectric switch is distributed on the arc line corresponding to the above eccentric hole, and the photoelectric switch is used to send out the detection signal.

Further, the limit controller indicates the position of the lifting height in real time through the superimposition of the number of forward and reverse rotations by the embedded chip, and controls the driving motor and the brake through the contacts of a relay when the crane hook is close to the upper and lower limit positions. Limit position power-off control.

Furthermore, the photoelectric rotation detection device has two or more sets of detection units, and the detection signals of multiple sets of detection units are collected through embedded chips to indicate and control the lifting height.

Compared with the existing detection device, the photoelectric rotation detection device of the present invention greatly reduces the number of holes provided on the rotating disc, while the number of corresponding photoelectric elements provided on the stationary support increases, thereby greatly reducing the manufacturing cost and reducing the cost of the entire device. The size makes the device easy to install and reliable in operation.

Since each detection unit adopts the method of setting a single hole on the rotating disk, the aperture can be made larger, which avoids the blurring of the signal boundary caused by the position shift of adjacent grids in the prior art, and the boundary of the generated signal is very clear ; At the same time, the disc body can be made more solid and small, so that the vibration and deformation of the equipment in the starting and braking stages have very little influence on the rotating disc and can be ignored. Adopting this detection unit makes the operation of the equipment very reliable.

The hoisting mechanism and the crane provided by the utility model are installed on the high-speed shaft of the hoisting mechanism with an electronic rotation amount detection device for measuring the steering and rotation amount of the high-speed shaft, and the reduction ratio of the deceleration mechanism is generally 20- Between -40, this is equivalent to encrypting the photoelectric detection mark of the code disc on the side of the low-speed rotating shaft with the hoisting device transferred by 20-40 times or increasing the size of the code disc by many times, which is very important for the existing detection In terms of structure, it is unrealizable. The utility model installs an electronic rotation amount detection device on the high-speed shaft, and the detection and control accuracy is improved by 20-40 times, so that the lifting measurement accuracy of the lifting mechanism can be improved to the order of 10 digits ( If the original control accuracy is at the meter level, the utility model can reach the centimeter-millimeter level), the measurement and control accuracy has been greatly improved, and the high-precision measurement and control has been truly realized, and the measurement errors and errors in the starting and braking stages have been substantially avoided The occurrence of over-limit lifting and lowering caused by error accumulation eliminates potential safety hazards in on-site construction or equipment use.

Description of drawings

Fig. 1 is the structure schematic diagram of the lift limit control system of the present utility model;

Fig. 2 is the front view of the photoelectric detection device in Fig. 1;

Fig. 3 is the left view of Fig. 2;

Fig. 4 is a perspective view of Fig. 2;

Fig. 5 is a schematic diagram of a circuit layout of a limit controller;

Fig. 6 is a work flow chart of the height limit of the lifting limit control system;

Fig. 7 is a schematic diagram of a redundant photoelectric detection device;

Fig. 8 is a structural schematic diagram of the lifting mechanism;

Fig. 9 is a schematic diagram of the installation position of the photoelectric detection device in the lifting mechanism.

Detailed ways

Embodiment of lifting limit control system

As shown in Figure 1, a lifting limit control system includes a photoelectric rotation detection device and a limit controller. The detection signal sent by the photoelectric rotation detection device is sent to the limit controller, and the control output of the limit controller is connected to the limit controller. The start-stop controller of the drive motor and the control connection of the brake mechanism controller.

The photoelectric rotation detection device has a detected rotating disk for assembling with the corresponding shaft of the deceleration mechanism and a stationary bracket for detection with a photoelectric switch installed facing the rotating disk; the photoelectric rotation detection device has A set of detection units, each set of detection units is composed of an eccentric hole set on the rotating disc and a group of photoelectric switches set on the stationary support, each photoelectric switch is distributed on the arc line corresponding to the above eccentric hole, the photoelectric switch Used to send out the detection signal.

The photoelectric switch is used to detect the corresponding eccentric hole on the rotating disc. The eccentric hole adopts a round hole (also can adopt other shapes). The rotation direction of the rotating disc can be conveniently determined by using three photoelectric switches. If the number of photoelectric switches is further increased, the detection accuracy can be further improved. The photoelectric sensors are evenly arranged on the stationary support, and the three photoelectric switches form an arc line corresponding to the core hole.

When the eccentric hole passes through the photoelectric switch, the photoelectric switch produces a state switch and generates a transition signal. The limit controller detects the jump signal sent by each photoelectric switch, so that it can measure the steering of the rotating disc, the number of rotations and other signals. The limit controller can display these signals through the display screen, and the control data input part is a keyboard for inputting setting parameters. As other implementation manners, the display screen and the keyboard can also be implemented with a touch screen.

In order to perform dynamic balance, a corresponding dynamic balance block for dynamically balancing the eccentric hole is also provided on the disc body of the rotating disc.

The specific technical means will be described one by one below in conjunction with the accompanying drawings.

Among them, the photoelectric rotational amount detection device is shown in Figures 2, 3 and 4. It mainly includes two parts, the rotating disc and the stationary bracket.

As for the rotating disc, as shown in Figures 2, 3 and 4, it has a disc-shaped body 11 with an axis extending in the left-right direction, and a through hole 13 with an axis extending in the left-right direction is eccentrically arranged on the disc-shaped body 11 . The disc-shaped body 11 forms an annular rotating disc through the outer circumference and the inner circle 14, and a circular channel 6 is formed in the middle, and the circular channel 6 is used for passing the rotating shaft.

As another embodiment, if the rotating disc is installed at the end of the rotating shaft, the above-mentioned circular channel may not be provided, but a corresponding groove structure may be provided.

An eccentric hole, that is, a through hole 13 is arranged on the disc-shaped body 11 . If the rotating disc is installed on a high-speed shaft, it will have a higher rotational speed. After the hole is opened, the quality of the disc-shaped body 11 will be unbalanced. In order to compensate for the loss of moment of inertia caused by the through hole, a A mass compensating block 12 is installed on the connecting line with the center of the through hole 13, which is a solid circular block eccentrically arranged with the through hole 13. The moment of inertia of the through hole 13 is simplified as the moment of inertia of the center of mass to the center of the disc, and the moment of inertia of the through hole 13 is I ₁ =m ₁ r ₁ ² , where m ₁ is the original mass of the through hole, that is, the lost quality; _r1 is the distance from the center of the through hole to the center of the rotating disc. In order to compensate the moment of inertia of this part, the moment of inertia of the mass compensation block 12 to the rotation axis of the rotating disk is I ₂ =I ₁ =m ₂ r ₂ ² , where m ₂ is the mass of the mass compensation block, and r ₂ is the mass compensation block The distance from the center of to the center of the rotating disc. The specific m ₂ and r ₂ can be determined according to the specific situation, as long as the moment of inertia obtained by their product is equal to the moment of inertia lost by the through hole.

The rotating disc can be installed on the high-speed shaft corresponding to the reduction mechanism, or on the low-speed rotating shaft corresponding to the reduction mechanism. When installed on the high-speed shaft, the detection accuracy can be greatly improved. See the embodiment of the lifting mechanism for details about the installation location.

Another important component of the photoelectric rotation detection device—the stationary support 2, is fixedly placed on the right side of the rotating disk. The stationary support 2 is a C-shaped support. The notch is inserted, that is, the rotating shaft passes through the bracket and does not touch the bracket. This setting not only facilitates the assembly of the bracket, but also ensures good rotation of the high-speed shaft. The rotating disc rotates with the high-speed shaft, and the stationary support 2 is stationary relative to the frame, and relatively independent from the rotating disc.

A photoelectric switch corresponding to the through hole 13 is arranged on the stationary support 2 . The photoelectric switch includes a signal transmitter and a signal receiver that transmit signals to and receive signals from the through hole. Photoelectric switches include through-beam and reflective. The signal transmitter and signal receiver in the through-beam photoelectric switch are separated, coaxially arranged on both sides of the object, and a switch signal will be generated when the beam is interrupted. ; The signal transmitter and signal receiver in the reflective photoelectric switch are set together, and the beam emitted from the transmitter is reflected by the object and then returns to the receiver. When the beam is interrupted, a switch signal will be changed.

In this embodiment, since the stationary bracket is arranged on the right side of the rotating disk, a reflective photoelectric switch is selected. As another embodiment, if a through-beam photoelectric switch is selected, the shape of the stationary support needs to be changed, and a corresponding supporting structure needs to be added to the left side of the rotating disc to support a part of the photoelectric switch. The static bracket can also have other implementations, for example: a blocking piece is provided on the upper end of the C-shaped bracket to block the gap of the C-shaped bracket to form a closed shape, and the high-speed shaft is surrounded therein.

Here, a representative infrared reflective switch is taken as an example, the infrared reflective switch is a reflective photoelectric switch, and the emitted signal is an infrared signal.

The infrared reflection switch can set the detection distance. If there is an object in this distance that blocks the infrared rays emitted by the infrared reflective switch, the infrared reflective switch will show a state different from that when there is no object (that is, high level and low level). Here, when the infrared rays pass through the through hole on the rotating disk, it will produce a different state than when the rotating disk reflects the signal back to the infrared reflective switch.

As shown in Figures 2, 3 and 4, three infrared reflective switches are evenly arranged on the stationary support 2 within a circle (ie 360°), that is, the interval angle between the three switches is 120°. The limit controller is connected with these three switches at the same time, and the distance from the center of the through hole to the center of the rotating disc is equal to the radius of the circle. The three infrared reflective switches are parallel, that is, the three switches are detected at the same time, and the limit controller judges the difference between the detected states of the three infrared reflective switches to determine which infrared reflective switch has passed through the through hole, and then A series of calculations such as counting. In this embodiment, the through hole 13 and the three infrared reflective switches form a detection unit.

Assume that when the hook is raised, the direction of rotation of the motor is forward; when the hook is lowered, the direction of rotation of the motor is reverse. The limit controller is embedded in the prepared program in advance, and judges whether the reel is rotating forward or backward according to the time sequence in which one of the three infrared reflection switches receives a different state from the other two. That is, it is assumed that when the state of the infrared reflection switch 31 is first shown as passing through the circular hole, if the next one showing this state is the infrared reflection switch 32, it indicates that the motor is rotating forward at this time; if the next signal received is the infrared reflection switch 33, it means that the motor is reversed at this time. If the state firstly shows that the switch passing through the round hole is the infrared reflective switch 32 or the infrared reflective switch 33, the same is true.

If only one infrared photoelectric switch is provided, although the rotation direction of the rotating disk cannot be determined during detection, the lifting height of the device can also be detected. If two photoelectric switches are arranged so that the two photoelectric switches are not on the same diameter, the direction of rotation can be judged by detecting the signal switching interval of the two photoelectric switches.

A limit controller 5 and a bottom plate 4 for fixing the control device on the bracket are fixedly arranged on the stationary bracket 2 . Limit controller 5 wherein comprises single-chip microcomputer. The single-chip microcomputer is connected to the infrared reflection switch, specifically: the single-chip microcomputer control is connected to the signal transmitter, and the sampling is connected to the signal receiver. The data is processed according to the signal transmitted by the infrared reflective switch. Limit controller 5 as shown in Figure 5, is made up of single-chip microcomputer 51, relay 52, triode 53, buzzer 54, four nixie tubes 55 and keyboard 56. The relay 52 is used to control the start and stop of the lifting motor and the brake, and the buzzer 54 is used for reporting to the police.

The limit controller can be installed on the stationary support and form a whole with the photoelectric rotation detection device. As another embodiment, the limit controller can also be set separately from the photoelectric rotation detection device. In this case, the photoelectric rotation detection device needs to be provided with an output signal port, and the limit controller should also be provided with a corresponding interface. When installing on site, just connect the signal port with the interface of the limit controller.

The display and control data input part of the lifting data can be installed at the installation position of the limit controller, or installed in the cab, which is convenient for the driver, and can even be set separately.

Due to the different structures and working environments of various types of equipment, the reduction ratio of the reducer of the mechanism itself is different, the magnification of the pulley block is different, and the diameter of the reel is also different, so the limited lifting height is different. Therefore, in order to achieve the purpose of judging the lifting (or descending) height reasonably and giving a power-off alarm, an input module (ie, a keyboard 56 ) is added to the limit controller 5 . After being installed in different lifting mechanisms, the limited lifting height, initial position, reduction ratio of the reducer, drum diameter and the ratio of the lifting mechanism can be input according to the actual situation. So that the single-chip microcomputer can calculate according to the signal detected by the infrared reflection switch, and judge whether the hook, lifting platform, hanging cage, etc. have reached the limit position.

The main function of the four-digit nixie tube 55 is as an auxiliary device when inputting, to remind the operator of the parameters to be input in the next step. In addition, when a lifting device, such as a crane, is lifting the hook, the four-digit digital tube can also add additional functions, such as displaying the average speed for reference. When it is lifted up and the hook runs to the limit position, the buzzer will give an alarm, and the four-digit digital tube will also have corresponding display content.

The working environments of various types of reel lifting devices are different. In a dusty working environment, the through holes on the rotating disc will be easily blocked, resulting in inaccurate measurement. Or accidentally dropped sundries will affect the influence of the infrared emission switch on the calculation of the single-chip microcomputer. Therefore, the entire photoelectric rotation detection device can be placed in the protective cover, so that it can work in a relatively less dusty environment. It can not only guarantee to work in a relatively clean environment, but also avoid the inaccurate lifting height limit caused by human error.

Figure 6 is a flow chart of limit control. For example, when the crane hook is lifted, the single-chip microcomputer 51 records the current total number of positive rotations according to the number of times received by a group of signals in combination with the judgment of forward rotation and reverse rotation, so as to calculate the current height of the suspension hook. When the hook reaches the limit height of the rise, the single-chip microcomputer 51 is connected to the buzzer 54 through the triode 53 to give an alarm, and the lifting motor is controlled through the relay 52 to stop the motor, but at this time only the forward rotation of the motor is limited, and the reverse rotation of the motor is not restricted . The relay 52 also controls the brake at the same time, so that the brake is locked and the reel stalls. This series of measures can enable the lifting motor to be powered off and the brake to be locked when the hook reaches the limit position of the lift.

When the operator wants to lower the hook, etc., the single-chip microcomputer 51 sends a signal to the relay 52 and the buzzer 54 . The buzzer 54 stops the alarm, and the relay 52 makes the brake release. Since the reverse rotation of the motor is not restricted when the hook reaches the limit position of ascent, the motor can realize reverse rotation without restriction. Due to various working conditions, the hook of the lifting device and the like also have restrictions on the lowering position. When the suspension hook descends, the single-chip microcomputer 51 also records the number of turns of the decline. When the suspension hook reaches the limit position of the decline, the single-chip microcomputer 51 sends signals to the buzzer 54 and the relay 52. The working process of the buzzer 54 at this time is the same as reaching the rising limit position, and the relay 52 stops the motor at this time, does not limit forward rotation, and makes the brake lock. When the operator of the hoisting mechanism makes the suspension hook etc. rise, the buzzer 54 stops the alarm, the motor rotates forward, and the suspension hook rises.

Three infrared reflective switches are evenly arranged within 360° on the bracket 2, which can control the error of the lifting height within one-third of the motor circle. The distance that the hook lifts is far less than the circumference of one circle of the reel. This can further reduce the error and make it more accurate. At the same time, due to the existence of the infrared reflective switch, the whole system has a higher sensitivity than the mechanical one.

The above embodiment provides an implementation with only one set of detection unit, wherein one set of detection unit is composed of an eccentric hole set on the rotating disc and a group of photoelectric switches set on the stationary support, each photoelectric switch is distributed in On the arc line corresponding to the above-mentioned eccentric hole.

According to the safety and stability requirements of the application, a photoelectric rotation detection device with two sets of detection units is also provided below, and an additional set of detection units is a redundant design. Of course, according to this idea, three or more detection units can also be designed.

As shown in FIG. 7 , the distances from the two eccentric holes corresponding to the two sets of detection units to the center of the rotating disc are different. The corresponding two groups of photoelectric switches form two concentric circles with different radii.

Two sets of detection units can output their respective detection signals at the same time, which are used by the limit controller: for example, under normal circumstances, the detection signal of the first detection unit is used, and when the detection signal output by the first detection unit is abnormal, the detection signal of the second The detection signals of the two sets of detection units.

The positions of the two eccentric holes require that they are not on the same circumference, and that the corresponding photoelectric switches are installed. If the two eccentric holes are arranged on two different radii of the same diameter, the size of the two eccentric holes can be calculated according to the principle of dynamic balance, so that the dynamic balance can be realized without setting a dynamic balance block. On the rotating disc, the more outside, the smaller the hole area is, as shown in hole 13 in Figure 7; The hole 13 and the corresponding photoelectric switches 31 , 32 , 33 form a first set of detection units, and the hole 12 and the corresponding photoelectric switches 34 , 35 , 36 form a second set of detection units.

Of course, if there are three eccentric holes in three sets of detection units, the position and size of the three eccentric holes can also be designed using the dynamic balance relationship to achieve dynamic balance.

Embodiment of lifting mechanism

As shown in Figure 8, the lifting mechanism, the key mechanism involves the drive motor, deceleration mechanism and reel mechanism, the drive motor is connected to the deceleration mechanism through the high-speed shaft, the deceleration mechanism is connected to the reel mechanism through the low-speed shaft, and the high-speed shaft is assembled There is a braking mechanism. The lifting mechanism also includes a lifting limit control system. The limit controller of the lifting limit control system controls the power-off of the drive motor and the brake at the limit position through the contact of a relay, and at the same time outputs signals to control the buzzer and warning lights. Wait for the police.

The lift limit control system is the same as the lift limit control system in the above embodiments, and will not be repeated here.

Regarding the installation position of the rotating disk of the photoelectric rotation detection device, it can be installed on the corresponding shaft of the deceleration mechanism. The corresponding shaft here includes not only the input shaft, the output shaft, the output shaft of the motor connected with the input shaft, but also the deceleration mechanism. intermediate shaft. Therefore, the installation position of the rotating disc is shown in Figure 1, which can be between the motor and the brake A (for the case where the brake is installed between the motor and the reducer, and the gap between the motor and the brake is large), the brake and the deceleration mechanism Between B (for the case where the brake is installed between the motor and the reducer, and the gap between the reducer and the brake is large). Or the intermediate shafts E and F of the reduction mechanism, and the output shaft G. In addition, the rotating disk can also be mechanically connected to the above-mentioned rotating shaft through gears or other reducers, such as the A' position in the figure, which is connected to the motor shaft A through gears, and the axis of the rotating disk is parallel to the axis of the high-speed shaft . When the rotating disk is installed on the high-speed shaft, the detection accuracy can be greatly improved.

Crane Example

The crane in this embodiment includes a driving motor and a lifting mechanism. The lifting mechanism adopts a lifting limit control system. The lifting mechanism and the lifting limit control system used in it are exactly the same as those of the foregoing embodiments, so no separate description will be made. .

The specific embodiments of the present utility model related to the three subjects are given above, but the present utility model is not limited to the described embodiments. Under the idea given by the utility model, the technical means in the above-mentioned embodiments are transformed, replaced, and modified in ways that are easy for those skilled in the art, and the functions played are the same as those of the corresponding technical means in the utility model. They are basically the same, and the purpose of the utility model is also basically the same. The technical solution formed in this way is formed by fine-tuning the above-mentioned embodiments, and this technical solution still falls within the protection scope of the utility model.

Claims (12)

1. a lifting limit control system, comprise photo-electric rotation detecting device and limit controller, the detection signal that photo-electric rotation detecting device sends sends to limit controller, the control output of limit controller and drive motor start-stop controller and stop mechanism controller control linkage; It is characterized in that, described photo-electric rotation detecting device have one for the detected rotary disk that carries out assembling with the respective shaft of speed reduction gearing and one and rotary disk just right, the detection stationary bracket that is provided with photoelectric switch; Described photo-electric rotation detecting device has at least a set of detecting unit, often overlap detecting unit to be made up of one group of photoelectric switch that the eccentric orfice that rotary disk is arranged and stationary bracket are arranged, each photoelectric switch is distributed on the circular arc line corresponding with above-mentioned eccentric orfice, and photoelectric switch is used for sending described detection signal.

2. lifting limit control system according to claim 1, is characterized in that, photo-electric rotation detecting device has two covers or two and overlaps above detecting unit.

3. lifting limit control system according to claim 1, is characterized in that, described rotary disk is assemblied on the high speed shaft of speed-changing mechanism.

4. the one lifting limit control system according to any one of claim 1-3, it is characterized in that, described three photoelectric switchs often overlapping detecting unit are uniformly distributed on the circular arc line of correspondence.

5. a lifting mechanism, comprises speed reduction gearing and drum mechanism built, and speed reduction gearing is used for connecting drive motor by high speed shaft, and speed reduction gearing is in transmission connection by slow-speed shaft and drum mechanism built, and high speed shaft is equipped with stop mechanism; Lifting mechanism also comprises lifting limit control system, lifting limit control system comprises photo-electric rotation detecting device and limit controller, the detection signal that photo-electric rotation detecting device sends sends to limit controller, the control output of limit controller and drive motor start-stop controller and stop mechanism controller control linkage; It is characterized in that, described photo-electric rotation detecting device have one for the detected rotary disk that carries out assembling with the respective shaft of speed reduction gearing and one and rotary disk just right, the detection stationary bracket that is provided with photoelectric switch; Described photo-electric rotation detecting device has at least a set of detecting unit, often overlap detecting unit to be made up of one group of photoelectric switch that the eccentric orfice that rotary disk is arranged and stationary bracket are arranged, each photoelectric switch is distributed on the circular arc line corresponding with above-mentioned eccentric orfice, and photoelectric switch is used for sending described detection signal.

6. lifting mechanism according to claim 5, is characterized in that, described limit controller carries out end position power-off control by the contact of a relay device to drive motor and drg.

7. lifting mechanism according to claim 5, is characterized in that, photo-electric rotation detecting device has two covers or two and overlaps above detecting unit.

8. lifting mechanism according to claim 5, is characterized in that, described rotary disk is assemblied on the high speed shaft of speed-changing mechanism.

9. the lifting mechanism according to any one of claim 5-8, is characterized in that, described three photoelectric switchs often overlapping detecting unit are uniformly distributed on the circular arc line of correspondence.

10. a hoisting crane, comprise the lifting mechanism of drive motor, speed reduction gearing and drum mechanism built composition, drive motor is in transmission connection by high speed shaft and speed reduction gearing, speed reduction gearing is in transmission connection by slow-speed shaft and drum mechanism built, and high speed shaft is equipped with stop mechanism; Lifting mechanism also comprises lifting limit control system, lifting limit control system comprises photo-electric rotation detecting device and limit controller, the detection signal that photo-electric rotation detecting device sends sends to limit controller, the control output of limit controller and drive motor start-stop controller and stop mechanism controller control linkage; It is characterized in that, described photo-electric rotation detecting device have one for the detected rotary disk that carries out assembling with the respective shaft of speed reduction gearing and one and rotary disk just right, the detection stationary bracket that is provided with photoelectric switch; Described photo-electric rotation detecting device has at least a set of detecting unit, often overlap detecting unit to be made up of the eccentric orfice that rotary disk is arranged and the one group of photoelectric switch arranged on the stationary bracket, each photoelectric switch is distributed on the circular arc line corresponding with above-mentioned eccentric orfice, and photoelectric switch is used for sending described detection signal.

11. hoisting cranes according to claim 10, it is characterized in that, described limit controller aligns the superposition of the reversion number of turns by embedded chip, real-time instruction lifting altitude position, and when crane hook closes on bound position, end position power-off control is carried out to drive motor and drg by the contact of a relay.

12. hoisting cranes according to claim 10 or 11, is characterized in that, photo-electric rotation detecting device has two covers or the above detecting unit of two covers, and are carried out lifting altitude instruction by the detection signal that detecting unit is overlapped in embedded chip collection more and controlled.