JP2014019535A - Self-traveling lifting apparatus - Google Patents

Abstract

In a self-propelled lifting device, even when the friction coefficient between a tether and a driving roller changes during traveling, a lifting operation with less driving torque and less slip is realized.
In a self-propelled lifting device that travels and moves up and down along a tether 100 disposed along a lifting path, the clamping force between a driving roller 2 and a driven roller 3 decreases with time. In addition to the control, when a speed difference of a predetermined value or more occurs between the driving roller and the driven roller, the clamping force is controlled to increase.
[Selection] Figure 1

Description

  The present invention relates to a self-propelled lifting device that travels along a path member disposed along a lifting path and moves up and down.

  As an elevating device, an elevator (elevating device) that raises and lowers a housing that accommodates a person or an object along a vertical direction or along a direction inclined with respect to the vertical direction is known. As a lifting device, a rope-type (traction type) that raises and lowers the housing by driving a rope (wire) that supports the housing without providing a lifting drive device is widely used. Yes. However, the rope type lifting device is driven by a rope, for example, in a case where the moving distance is long (for example, a case where it is used as a space elevator or an orbital elevator that moves up and down a lifting path extending from the earth to a geostationary orbit). , Difficult to adopt. On the other hand, a self-propelled lifting device that travels along a path member arranged along a lifting path and moves up and down is also known (Patent Document 1). If it is a self-propelled lifting device, it travels along the route member by a lifting drive device provided in the housing, so the route member can be fixedly arranged, and the rope-type lifting described above Even in cases where the device is not good at long lifting distances, it is relatively easy to adopt.

  In the self-propelled lifting device disclosed in Patent Document 1, a flat belt-like member is used as a path member instead of a wire having a circular cross section. The lifting device includes a driving roller and two driven rollers arranged so as to sandwich the driving roller in the lifting direction, and drives the two driven rollers and the belt so as to wind the belt around the driving roller by about a half circumference. Hold the belt between the rollers. Since the frictional force between the driving roller and the belt is ensured by sandwiching each driven roller and the driving roller, when the driving roller is driven to rotate, the driving roller rolls on the belt. Thereby, the raising / lowering apparatus to which the drive roller is attached can be raised / lowered along the belt.

  When the thickness of the belt is not uniform in the up-and-down direction, an excessive clamping force is generated when a thick belt portion is sandwiched between the driving roller and the driven roller, and the belt and the roller are easily worn. In view of this, the lifting device disclosed in Patent Document 1 uses an electric cylinder as an urging means for urging the driven roller with respect to the driving roller, and controls the electric cylinder to change its urging force. It can be configured. In this lifting device, a control unit that transmits a torque command to a drive source connected to the drive roller rotates the drive roller and detects a load torque value associated with the rotation drive. When the load torque value exceeds a predetermined threshold value, it is determined that a thick belt portion is sandwiched between the driving roller and the driven roller, and the electric cylinder is controlled to drive the driven roller with respect to the driving roller. Reduce the roller's urging force.

  On the other hand, when the detected load torque value becomes smaller than a predetermined threshold value, it is determined that a belt portion having a small thickness is sandwiched between the driving roller and the driven roller, and the electric cylinder is controlled to follow the driving roller. Increase the energizing force of Laura. According to Patent Document 1, by performing such control, the urging force of the driven roller with respect to the driving roller is dynamically adjusted to an appropriate value according to the load accompanying the rotational driving of the driving roller. As a result, it is possible to suppress the wear of the belt and the roller, and it is possible to drive up and down while suppressing the slip between the belt and the roller.

JP 2011-219267 A

  In general, in a self-propelled lifting device that travels along a path member such as a belt and moves up and down, in order to achieve energy efficient lifting drive, the path member and the drive rotor are as small as possible. It is required to prevent slippage between the two as much as possible. In order to prevent slippage, the frictional force between the path member and the drive rotor needs to be sufficiently large.

The frictional force F ₀ that can act between the drive rotator and the path member is expressed by μ = F ₀ / N, and the friction coefficient μ between the drive rotator and the path member, It is determined by the relationship with the vertical drag N acting between the driving rotating body. Since the drive rotator and the path member are selected for other purposes (such as wear resistance), there is a limit to increasing the coefficient of friction μ between them. On the other hand, if the clamping force between the driving rotating body and the driven rotating body that clamps the path member is increased, a high vertical drag N can be obtained. Therefore, when the frictional force between the path member and the drive rotator is increased in order to reduce slippage, the clamping force between the drive rotator and the driven rotator that sandwich the path member is increased to increase the high vertical drag N. Need to get. However, when the clamping force between the drive rotator and the driven rotator is increased, the drive torque for rotationally driving the drive rotator increases. Therefore, in order to realize an ascending / descending operation with less driving torque as much as possible, it is important to always apply the minimum necessary vertical drag N between the path member and the driving rotating body.

  However, the necessary minimum value of the vertical drag N varies depending on the friction coefficient μ between the drive rotor and the path member. The coefficient of friction μ changes every moment depending on environmental conditions such as temperature and humidity, and the type and amount of deposits interposed between the drive rotor and the path member. It will change every moment. At this time, if the friction coefficient μ is a parameter that can be directly observed, the clamping force between the driving rotator and the driven rotator is controlled according to the observation result of the friction coefficient μ, and the path member and the driving rotator are controlled. It is possible to stably operate the minimum necessary vertical drag N between the two. However, since the friction coefficient μ is not a parameter that can be directly observed, it is difficult to realize such control.

  On the other hand, in the lifting device disclosed in Patent Document 1, as described above, when it is detected that the load torque value is smaller than a predetermined threshold value, it is determined that a belt portion having a small thickness is sandwiched. Then, a control is made to compensate for the shortage of the vertical drag N between the driving roller and the belt, which is insufficient when the belt portion having a small thickness is sandwiched, by increasing the urging force of the driven roller. Suppress the occurrence of slipping due to lack. Therefore, the urging force of the driven roller that is set when the belt portion having a small thickness is sandwiched, that is, the clamping force between the driving roller and the driven roller is such that a sufficiently large vertical drag N that can sufficiently suppress the slip is obtained. Set to the correct value. The biasing force of the driven roller set in this way is maintained until the thick belt portion is sandwiched and the load torque value becomes larger than a predetermined threshold value. Therefore, although the raising / lowering device disclosed in Patent Document 1 can realize a raising / lowering operation with less slipping, a large driving torque is required over time, and an energy-efficient raising / lowering operation cannot be realized.

  The present invention has been made in view of the above background, and the object of the present invention is a self-propelled lifting device, even when the friction coefficient between the path member and the drive rotor changes during traveling. Another object of the present invention is to provide an elevating device capable of realizing an ascending operation or a descending operation with little driving torque and less slip.

In order to achieve the above object, a first aspect of the present invention is a self-propelled lifting device that travels along a path member disposed along a lifting path and is driven to rotate by a driving force from a driving source. A driving rotator, a driven rotator that sandwiches the path member between the driving rotator, a clamping force variation unit that varies a clamping force between the driving rotator and the driven rotator, and the drive Rotational speed information detecting means for detecting rotational speed information indicating the rotational speed of the rotating body and the driven rotating body, and the rotational speed of the driving rotating body and the rotation of the driven rotating body based on the detection result of the rotating information detecting means A determination means for determining whether or not a speed difference of a predetermined value or more has occurred with respect to the speed, and a control for operating the clamping force fluctuation means so that the clamping force decreases with time. The determination means If it is determined that the speed difference of the above value has occurred it is characterized in that it has a clamping force control means for controlling the 該挟 lifting force variation means to increase the 該挟 lifting force.
In general, even if the friction coefficient between the driven rotor and the path member is somewhat low, no substantial slip occurs between them, but the friction coefficient is low between the drive rotor and the path member. As a result, slippage is likely to occur between them. When slippage occurs between the drive rotator and the path member, the rotation speed of the drive rotator rapidly increases due to a decrease in load torque, and a difference in rotation speed occurs between the drive rotator and the driven rotator. Therefore, by detecting this rotational speed difference, it can be grasped that the friction coefficient between the drive rotator and the path member has decreased so as to cause slippage. In this self-propelled lifting device, control is performed to increase the clamping force between the drive rotator and the driven rotator when a rotational speed difference of a predetermined value or more occurs. Accordingly, by appropriately setting the predetermined value, the normal force N acting between the drive rotating body and the path member can be increased at an early stage of slipping, and slipping can be quickly eliminated.
On the other hand, in the present self-propelled lifting device, even if the holding force is increased in this way, control is performed to decrease the holding force with time. Therefore, the large pinching force after the increase is not always maintained, and the pinching force gradually decreases after being increased as described above. Since the clamping force gradually weakens in this way, the slip will begin to occur again, but at that time, the control to increase the clamping force is performed again, and the slip immediately disappears. By continuing such control, even if the friction coefficient between the drive rotator and the path member changes every moment, the clamping force between the drive rotator and the driven rotator does not cause slippage. The fluctuation is repeated within the minimum necessary range. As a result, the driving torque of the driving source can be stably suppressed within the necessary minimum range.

The invention according to claim 2 is the self-propelled lifting device according to claim 1, wherein the drive rotating body and the driven rotating body are arranged so as to sandwich the path member from a direction orthogonal to the lifting path. It is characterized by being.
In a case where the ascending / descending distance is long, it is necessary to arrange the path member along such a long ascending / descending distance. In this case, it is necessary to stretch the path member with a very strong tension. In this case, it is impossible to realize a configuration in which the belt (path member) is wound about a half circumference around the drive roller (drive rotator) as in the lifting device disclosed in Patent Document 1. According to the present self-propelled lifting device, the path member can be sandwiched between the drive rotator and the driven rotator so as to be self-propelled without substantially winding the path member around the drive rotator. Therefore, it is possible to deal with a path member that is stretched with a very strong tension.

According to a third aspect of the present invention, in the self-propelled lifting device according to the first or second aspect, when the determination means determines that a speed difference of a predetermined value or more has occurred, the rotational torque of the drive rotating body is reduced. It has a driving force control means.
When slip occurs between the drive rotator and the path member, the load torque applied to the drive rotator decreases, resulting in an increase in the rotational speed of the drive rotator and a further progress of the slip. In this self-propelled lifting device, if the determination means determines that a speed difference of a predetermined value or more has occurred, the rotational torque of the drive rotator is reduced, so that an increase in the rotation speed of the drive rotator due to slipping is suppressed. As a result, it is possible to quickly prevent slippage by suppressing an increase in the speed difference between the drive rotator and the path member.

According to a fourth aspect of the present invention, in the self-propelled lifting device according to any one of the first to third aspects, a braking force is applied to at least one of the driving rotating body and the driven rotating body. When lowering the braking force applying means and the self-propelled lifting device, the drive source is turned off so that the drive rotator can be driven to rotate with respect to the path member, and the detection result of the rotation information detection means A lowering control means for controlling the braking force applying means so that the rotational speed of the driving rotary body or the rotational speed of the driven rotary body obtained from is a target lowering speed, and the clamping force control means, When the self-propelled lifting device is raised, the control is performed, and when the self-propelled lifting device is lowered, between the at least one rotating body to which the braking force is applied and the path member. The self-propelled lifting device It is characterized in that the frictional force that can cause fast to control the clamping force variation means to act.
When the self-propelled lifting device is lifted, the above-described clamping force control is performed to realize a lifting operation in which the driving torque of the driving source is suppressed within a necessary minimum range. On the other hand, at the time of lowering, the drive source is turned off and the drive rotator is driven to rotate with respect to the path member, and descends along the path member due to its own weight. . Such descending control can realize an energy efficient descending operation as compared with the case of controlling the descending speed while controlling the driving force of the driving source.

  According to the present invention, in a self-propelled lifting device, even when the friction coefficient between the path member and the drive rotating body changes during traveling, an ascending operation or a descending operation with less slip can be realized with a small driving torque. An excellent effect is obtained.

It is a perspective view which shows the drive device which is the principal part of the raising / lowering apparatus which concerns on embodiment. It is the expansion perspective view which expanded the part containing the pressurization adjustment mechanism which fluctuates clamping force when clamping a tether between the driving roller and driven roller in the drive device. It is a control block diagram in connection with the control system of the drive device. It is a flowchart which shows the flow of the clamping force adjustment control in embodiment.

Hereinafter, an embodiment in which the self-propelled lifting device according to the present invention is applied to a lifting device that travels on a belt that is a path member will be described.
FIG. 1 is a perspective view showing a drive device that is a main part of a lifting device 1 according to the present embodiment.
This elevating device 1 uses a tether 100 that is a belt-like member as a path member disposed along a predetermined elevating path, and can travel up and down along the tether 100. Although the tether 100 may be arranged along the vertical direction, in the present embodiment, the tether 100 is arranged obliquely with respect to the vertical direction. The lifting device 1 assumes a case where the lifting distance is long, and therefore the tether 100 is stretched with a strong tension. Examples of such cases include the use of lifting devices to clean and inspect high-rise buildings and towers, and the use of lifting devices as space elevators or orbital elevators that move up and down the elevating path that extends from the earth to a geostationary orbit. There are various cases such as The lifting device 1 has various parts such as a housing (gauge) attached to the driving device shown in FIG. 1 according to the application, but the description of these parts is omitted.

  As shown in FIG. 1, the lifting device 1 includes a driving device including a driving roller 2 as a driving rotating body that sandwiches the tether 100 and a driven roller 3 as a driven rotating body. The driving roller 2 is rotationally driven by a driving force from a driving motor 4 that is a driving source. The driven roller 3 rotates following the tether 100. The driving roller 2 and the driven roller 3 are disposed so as to sandwich the flat surface of the tether 100 from a direction orthogonal thereto. Therefore, when the tether 100 is sandwiched between the driving roller 2 and the driven roller 3, the tether 100 is not wound around the driving roller 2, so that the driving roller 2 and the driven roller are also applied to the tether 100 stretched with a very strong tension. 3 can be sandwiched. Of course, if possible, the tether 100 may be sandwiched between the driving roller 2 and the driven roller 3 so that the tether 100 is wound around the driving roller 2.

  The lifting device 1 is provided with shift prevention guides 5A and 5B in order to suppress the shift of the tether 100 in the direction of the rotation axis of the drive roller 2. Each shift prevention guide 5A, 5B has guide rollers 6A, 6B and base plates 7A, 7B, and the tether 100 is passed between them. The driving device of the lifting / lowering device 1 is supported by the tether 100 at three points: two shift prevention guides 5A and 5B, and a driving roller 2 and a driven roller 3 that sandwich the tether 100 therebetween. The lifting device 1 also includes an electric circuit board for performing various controls, a storage box 8 for storing a power source, and the like.

FIG. 2 is an enlarged perspective view in which a portion including a pressure adjusting mechanism serving as a clamping force changing means for changing a clamping force when the tether 100 is clamped between the driving roller 2 and the driven roller 3 is enlarged.
The driving roller 2 is attached between the two side structures 11A and 11B in the fixed frame 10. The two side structures 11A and 11B are integrated by a stay 12 or the like. On the other hand, the driven roller 3 is rotatably mounted between the two side structures 21A and 21B in the movable frame 20. The two side structures 21A and 21B are integrated by the back plate 22 and the like. The movable frame 20 is coupled to the fixed frame 10 so that the guide frames 13A and 13B attached to the side structures 11A and 11B of the fixed frame 10 enter the side structures 21A and 21B. Yes. The movable frame 20 is fixed to the fixed frame 10 in a state in which the movement of the movable frame 20 is restricted by the guide frames 13A and 13B in the contact / separation direction between the driven roller 3 and the driving roller 2 (direction perpendicular to the flat surface of the tether 100). On the other hand, it is configured to be movable.

  Holding force adjusting motors 31A and 31B as clamping force varying means for adjusting the clamping force are attached to the outer surfaces of the side structures 11A and 11B of the fixed frame 10, respectively. Each of the clamping force adjusting motors 31A and 31B is formed of a stepping motor, and the motor shaft extends along the contact / separation direction between the driven roller 3 and the driving roller 2 (a direction orthogonal to the flat surface of the tether 100). Yes. Screw shafts 32A and 32B are fixed to the end of each motor shaft so as to be coaxial. The screw shafts 32A and 32B include guide plates 14A and 14B fixed to the guide frames 13A and 13B of the fixed frame 10 and guide holes (not shown) provided in the elastic rubbers 15A and 15B fixed thereto, and the movable frame 20. The guide plates 24A and 24B fixed to the side structures 21A and 21B are disposed through guide holes (not shown) provided in the guide plates 24A and 24B.

  Nuts 33A and 33B are attached to the distal ends of the screw shafts 32A and 32B, and spring bases 34A and 33B are attached to the nuts 33A and 33B. The spring bases 34A and 33B have guide holes through which the two guide rails 35A and 35B fixed to the guide plates 24A and 24B of the movable frame 20 pass, and are movable along the two guide rails 35A and 35B. It has become a structure. Compression springs 36A and 36B as urging means are arranged between the spring bases 34A and 33B and the guide plates 24A and 24B so as to be coaxial with the screw shafts 32A and 32B. The spring pedestals 34A and 33B are integrally supported by the fixed frame 10 to which the clamping force adjusting motors 31A and 31B are fixed through the screw shafts 32A and 32B. Therefore, the urging force by the compression springs 36 </ b> A and 36 </ b> B becomes an urging force that urges the movable frame 20 to which the guide plates 24 </ b> A and 24 </ b> B are fixed toward the fixed frame 10. Therefore, the urging force of the compression springs 36 </ b> A and 36 </ b> B acts as a clamping force for clamping the tether 100 between the driven roller 3 supported by the movable frame 20 and the driving roller 2 supported by the fixed frame 10.

  In the pressure adjusting mechanism as described above, when the clamping force adjusting motors 31A and 31B are driven to rotate the screw shafts 32A and 32B, the nuts 33A and 33B are rotated in the screw shaft direction in a state where the rotation around the screw shaft is restricted. Move to. Therefore, the spring pedestals 34A and 33B fixed to the nuts 33A and 33B move along the two guide rails 35A and 35B. As a result, the distance between the spring pedestals 34A and 33B and the guide plates 24A and 24B changes, and the amount of compression (the amount of contraction) of the compression springs 36A and 36B arranged therebetween changes. As a result, the clamping force between the driven roller 3 and the driving roller 2 can be changed.

  In the present embodiment, pressure sensors 41A and 41B are provided between the elastic rubbers 15A and 15B and the guide plates 24A and 24B. Since the pressing force between the elastic rubbers 15A and 15B and the guide plates 24A and 24B is generated by the urging force of the compression springs 36A and 36B, the detection results of the pressure sensors 41A and 41B are the driven roller 3 and the driving roller. 2 indirectly indicates the clamping force between the two.

  In the present embodiment, the driving roller encoder 42 serving as a rotational speed information detecting unit for detecting the rotational speed of the driving roller 2 and the rotational speed information detecting unit for detecting the rotational speed of the driven roller 3 are used. The driven roller encoder 43 is provided. The encoders 42 and 43 are provided on the respective roller shafts, and can obtain rotational speed information of the rollers 2 and 3 from output pulses output per unit time.

  In the present embodiment, a disc-type electromagnetic brake 44 is provided as a braking force applying means for controlling the descending speed when the elevating device 1 is lowered. In addition, as a braking force provision means, a well-known brake mechanism etc. can be utilized widely. The electromagnetic brake 44 is provided with a first disk 44A provided with an electromagnet and a second disk provided with a permanent magnet facing each other. One disk (in this embodiment, the first disk 44A) is attached to the side structure 11B, and the other disk (in this embodiment, the second disk 44B) is linked to the rotating shaft of the drive roller 2. It is attached to the brake shaft 45 that rotates. When an electric current is passed through the electromagnet of the first disk 44A, it is repelled from the permanent magnet by the action of the magnetic field generated by the electromagnet, the two disks 44A and 44B are separated, and the braking force does not act on the brake shaft 45. On the other hand, when the current to the electromagnet of the first disk 44A is cut off, both disks 44A and 44B are attracted by the action of the magnetic field by the permanent magnet, and the braking force acts on the brake shaft 45.

Next, the control content of this embodiment performed in order to implement | achieve the upward movement of the raising / lowering apparatus 1 with few slips and energy efficiency is demonstrated.
In the present embodiment, the drive motor 4 is controlled to be driven at a constant target rotational speed corresponding to the target ascent speed in order to raise the elevating device 1 along the tether 100 at a constant target ascent speed. During the upward movement, an electric current is passed through the electromagnet of the first disk 44A so that the braking force does not act on the braking shaft 45 interlocked with the rotating shaft of the drive roller 2. In order for the elevating device 1 to rise stably at the target ascending speed, it is necessary for the driving roller 2 to rotate with respect to the tether 100 without slipping and to roll. However, the coefficient of friction between the driving roller 2 and the tether 100 changes every moment depending on environmental conditions such as temperature and humidity, and the kind and amount of deposits interposed between the driving roller 2 and the tether 100. is there. Therefore, when the friction coefficient decreases, the drive roller 2 can slip with respect to the tether 100. At this time, if the clamping force between the driving roller 2 and the driven roller 3 is set sufficiently large in advance so that slip does not occur even if the friction coefficient decreases, the rotational load of the driving roller 2 increases and the driving force increases. The driving torque required for the motor 4 is increased, and the energy efficiency is deteriorated. Therefore, in the present embodiment, the following control is performed to control the clamping force between the driving roller 2 and the driven roller 3 within the minimum necessary range, thereby reducing slipping and increasing energy efficiency. Realize the move.

FIG. 3 is a control block diagram related to the control system of the drive device of the lifting device 1 in the present embodiment.
FIG. 4 is a flowchart showing the flow of the clamping force adjustment control in the present embodiment.
First, the clamping force adjusting unit 53 of the control unit 50 controls the clamping force adjusting motors 31A and 31B to set the clamping force between the driving roller 2 and the driven roller 3 to a predetermined initial value (S1). ). This initial value is set to a pinching force that does not cause slippage even when a possible decrease in the friction coefficient occurs. Thereafter, the drive control unit 51 of the control unit 50 starts driving the drive motor 4 (S2), and starts to acquire rotational speed information of the drive roller 2 from the drive roller encoder 42. Then, until the rotational speed of the drive roller 2 reaches a target rotational speed corresponding to the target ascent speed, the drive current input to the drive motor 4 is controlled according to a predetermined speed increase profile, and the speed increase control of the drive motor 4 is performed. (S3).

  The clamping force during the acceleration period from when the lifting device 1 starts to move up to when the drive roller reaches the target rotational speed is maintained constant at the initial stage described above, and during the acceleration period, slip is suppressed rather than energy efficiency. In particular, he places particular importance. After the rotation speed of the drive motor 4 reaches the target rotation speed (Yes in S4), the drive control unit 51 maintains the target rotation speed of the drive roller 2 based on the output result of the drive roller encoder 42. Thus, the drive motor 4 is feedback-controlled.

  When the rotational speed of the drive motor 4 reaches the target rotational speed (Yes in S4), the control unit 50 performs clamping for controlling the clamping force between the driving roller 2 and the driven roller 3 within a necessary minimum range. Force adjustment control is started. Specifically, first, the clamping force adjusting unit 53 serving as a clamping force control unit holds the clamping force adjusting motors 31A and 31B so that the clamping force between the driving roller 2 and the driven roller 3 is reduced by a predetermined reduction amount. Is controlled (S5). Thereafter, the speed difference determination unit 52 of the control unit 50 acquires the rotational speed information of the driving roller 2 and the driven roller 3 from the driving roller encoder 42 and the driven roller encoder 43, and the rotational speed between the rollers 2 and 3. Is detected (S6). Then, the speed difference determination unit 52 determines whether or not the detected speed difference exceeds a predetermined threshold (S7).

  When the speed difference determination unit 52 determines that the threshold value is exceeded (Yes in S7), the speed difference determination unit 52 sends the determination result to the clamping force adjustment unit 53. Accordingly, the clamping force adjusting unit 53 controls the clamping force adjusting motors 31A and 31B so that the clamping force between the driving roller 2 and the driven roller 3 is increased by a predetermined increase amount (S8). The threshold value in the present embodiment is set to a value corresponding to the rotational speed difference between the driving roller 2 and the driven roller 3 that occurs when a slight slip occurs between the driving roller 2 and the tether 100. Therefore, in the present embodiment, the clamping force between the driving roller 2 and the driven roller 3 immediately increases at the stage where a slight slip occurs (the stage at which the slip begins to occur), and the driving roller 2 and the tether 100 The normal drag acting between them increases. As a result, the frictional force between the drive roller 2 and the tether 100 can be increased, and the slip state is eliminated.

  On the other hand, when the speed difference determining unit 52 determines that the difference in rotational speed between the driving roller 2 and the driven roller 3 does not exceed the threshold value (No in S7), until the driving stop timing of the driving motor 4 arrives. (No in S9), the processes in steps S5 to S8 are repeated. Therefore, until the difference in rotational speed between the rollers 2 and 3 exceeds the threshold (until slight slip occurs), the clamping force decreases stepwise, and the difference in rotational speed between the rollers 2 and 3 is the threshold. As soon as the value exceeds the value, the control of increasing the clamping force and eliminating the slipping state is repeated. With such control, according to the present embodiment, a constant speed period in which the drive motor 4 is controlled at a constant rotational speed even in a situation where the friction coefficient between the drive roller 2 and the tether 100 varies every moment. During this, the clamping force between the driving roller 2 and the driven roller 3 can be stably suppressed within a necessary minimum range in which substantial slip does not occur (slight slip occurs).

  When the drive stop timing of the drive motor 4 has arrived (Yes in S9), the clamping force adjusting unit 53 controls the clamping force adjusting motors 31A and 31B to generate the clamping force between the driving roller 2 and the driven roller 3. The initial value described above is set (S10). Thereafter, the drive control unit 51 performs deceleration control of the drive motor 4 according to a predetermined deceleration profile (S11), and stops the drive motor 4 at a target drive stop timing. In the present embodiment, the clamping force during the acceleration control and the deceleration control is set to the same value (initial value). However, when the clamping force suitable for each control is different, different clamping forces are used. It may be set to a value.

  In the present embodiment, the clamping force is decreased stepwise until the difference in rotational speed between the rollers 2 and 3 exceeds the threshold value (until slight slip occurs). The clamping force adjustment control for increasing the slip state to be increased is not performed during the acceleration control or the deceleration control, but may be performed during the acceleration control or the deceleration control.

  In the present embodiment, when the speed difference determination unit 52 determines that the threshold value is exceeded (Yes in S7), the drive control unit 51 reduces the drive current input to the drive motor 4 to drive The drive motor 4 may be controlled so as to reduce the drive torque of the roller 2. Thereby, the state in which slight slip is generated between the drive roller 2 and the tether 100 can be recovered more quickly.

  In the present embodiment, the increase amount of the clamping force when the speed difference determination unit 52 determines that the threshold value is exceeded (when a slight slip occurs) may be a predetermined constant increase amount. It may be variable. For example, the friction coefficient between the driving roller 2 and the tether 100 at the time when the slight slip occurs is estimated according to the magnitude of the clamping force at the time when the slight slip occurs, and from the estimated value of the friction coefficient Determine the amount of increase in pinching force.

  When lowering the lifting device 1, first, the drive motor 4 is turned off by the drive control unit 51 functioning as a lowering control unit, and the driving roller 2 and the driven roller 3 are clamped by the clamping force adjusting unit 53. Loosen the force to the specified value. The predetermined value is vertical enough to apply a frictional force capable of decelerating the descending lifting device 1 between the driving roller 2 to which the braking force is applied by the electromagnetic brake 44 and the tether 100. It is set to a value that provides drag. The drive roller 2 is in a state in which it can be driven and rotated with respect to the tether 100 in the same manner as the driven roller 3 because the drive motor 4 is turned off. Therefore, the lifting device 1 is lowered along the tether 100 by its own weight. . The braking force control unit 54 functioning as a descent control means is based on the detection result of at least one of the drive roller encoder 42 and the driven roller encoder 43 (in this embodiment, the detection result of the driven roller encoder 43 is used). The current supplied to the electromagnet of the electromagnetic brake 44 is controlled so that the descending speed of the lifting device 1 follows the target speed. When a braking force is applied by the electromagnetic brake 44, the driven rotation of the driving roller 2 is hindered, and the speed of the elevating device 1 can be reduced by the frictional force between the driving roller 2 and the tether 100.

  In the present embodiment, the control of the clamping force when the lifting device 1 is raised is different from the control of the clamping force when the lifting device 1 is lowered. For example, the same clamping force as that when the lifting device 1 is lowered is the same. Control may be performed.

DESCRIPTION OF SYMBOLS 1 Lifting device 2 Drive roller 3 Driven roller 4 Drive motor 10 Fixed frame 11 Side structure 13 Guide frame 14 Guide plate 15 Elastic rubber 20 Movable frame 21 Side structure 24 Guide plate 31 Clamping force adjustment motor 32 Screw shaft 34 Spring Pedestal 35 Guide rail 36 Compression spring 41 Pressure sensor 42 Drive roller encoder 43 Driven roller encoder 50 Control unit 51 Drive control unit 52 Speed difference determination unit 53 Nipping force adjustment unit 54 Braking force control unit 100 Tether

Claims (4)

In the self-propelled lifting device that travels along the path member arranged along the lifting path and moves up and down,
A drive rotator that is rotationally driven by a driving force from a drive source;
A driven rotator that sandwiches the path member with the drive rotator;
A clamping force varying means for varying a clamping force between the driving rotating body and the driven rotating body;
Rotational speed information detecting means for detecting rotational speed information indicating the rotational speeds of the drive rotator and the driven rotator;
Determination means for determining whether or not a speed difference of a predetermined value or more has occurred between the rotation speed of the driving rotating body and the rotation speed of the driven rotating body based on the detection result of the rotation information detecting means;
Control is performed to operate the clamping force variation means so that the clamping force decreases with time, and when the determination means determines that a speed difference of a predetermined value or more has occurred during the control, the clamping force is reduced. A self-propelled elevating device comprising: a clamping force control unit that controls the clamping force fluctuation unit so as to increase the clamping force variation unit. The self-propelled lifting device according to claim 1,
The self-propelled elevating device, wherein the drive rotator and the driven rotator are arranged so as to sandwich the path member from a direction orthogonal to the elevating path. In the self-propelled lifting device according to claim 1 or 2,
A self-propelled elevating device comprising drive force control means for reducing the rotational torque of the drive rotor when the judgment means judges that a speed difference of a predetermined value or more has occurred. In the self-propelled lifting device according to any one of claims 1 to 3,
Braking force applying means for applying a braking force to at least one of the driving rotating body and the driven rotating body;
When the self-propelled lifting device is lowered, the drive source is turned off so that the drive rotating body can be driven to rotate with respect to the path member, and the drive rotation obtained from the detection result of the rotation information detecting means A lowering control means for controlling the braking force applying means so that the rotational speed of the body or the rotational speed of the driven rotary body becomes a target lowering speed,
The clamping force control means performs the control when the self-propelled lifting device is raised, and the at least one rotating body to which the braking force is applied when the self-propelled lifting device is lowered. The self-propelled lifting device is controlled such that a frictional force capable of decelerating the self-propelled lifting device acts between the path member and the path member.

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