JPH04338089A - Braking device - Google Patents

Abstract

PURPOSE:To provide a high-performance and safe braking device actuated by small capacity-emergency power source even in the case of power failure or the like in addition to being compact but of large capacity, of high responsiveness and optionally-controlled braking force. CONSTITUTION:The force of pressing a shoe 22 to a drum or a disk 20, or the separating force is generated using a spring 24 and a hydraulic cylinder 25 jointly. The optimum braking force to the inertial mass and speed to be braked of a cage or the like is obtained, and the fluid pressure is controlled to control the force of pressing the shoe 22 to the drum or the disk 20. Accordingly, the optimum braking force is constantly generated to a braking device. In addition, a control device for controlling the pressure of the hydraulic cylinder 25 is operated by emergency power source.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a braking device for a drive device for raising and lowering a load using a lifting device such as an elevator or a crane.

0002

2. Description of the Related Art A lifting device is equipped with a braking device to maintain the position of the car when the car is stopped, and to safely brake and stop the car in an emergency such as a power outage while the car is running. This braking device uses a mechanical means such as a spring to press the shoe against the drum with a constant force, and the frictional force generated at this time generates a force to brake or hold the car. Generally, frictional force is the product of friction coefficient and pressing force, and the friction coefficient is nonlinear and is a function of sliding speed and pressing force. For this reason, the combination of materials for the drum and shoe, the optimal pressing surface pressure, etc. have been selected to stabilize the coefficient of friction. When operating the lifting device, this pressing force is electrically released and the car is driven by a motor or the like.

0003

[Problems to be Solved by the Invention] As the speed of the lifting device increases, the sliding speed range becomes wider, and the change in the frictional force of the braking device becomes large if only the conventional method is used. In other words, with the conventional structure in which the brakes are simply mechanically pressed with a constant force, the frictional force changes greatly depending on the sliding speed, making it difficult to achieve stable braking no matter the combination of materials selected. For this reason,
The braking acceleration changes, causing the braking distance to become longer or, conversely, causing a large braking shock. Particularly in the case of a structure in which the car is driven by a sheave via a rope, if the braking force is too large, slippage may occur between the rope and the sheave, making it impossible to brake the car. Also, slippage between the rope and sheave shortens the life of the rope.

[0004] As the stroke of the car becomes longer, the weight of ropes and the like increases, so the unbalanced weight becomes relatively smaller and the inertial mass to be braked becomes larger. Therefore, the braking force becomes relatively large even though the force for holding the car in the stopped position is relatively small. In other words, the braking force becomes much larger than the position holding force. Therefore, if an attempt is made to generate this braking force using mechanical means such as a spring, the device will be large-sized.

SUMMARY OF THE INVENTION An object of the present invention is to provide a safe braking device that is small in size and has a stable braking force from high to low speeds.

[0006]

SUMMARY OF THE INVENTION In the braking device of the present invention, a spring and a fluid pressure cylinder are used in combination to generate a force for pressing or separating a shoe from a drum or disk. Then, the control device determines the optimal braking force for the inertial mass and speed of the car etc., and controls the fluid pressure to control the force that presses the shoes against the drum or disk. Generates strong braking force. Furthermore, the control device that controls the pressure of the hydraulic cylinder is operated by emergency power.

[0007]

[Function] Under normal conditions, the car position is maintained by mechanical means, and in addition, fluid pressure is used to increase the position holding force to increase reliability, and in emergencies, the optimum control is applied to the inertial mass and speed to be braked. Since it is controlled by power, the car can be safely stopped with a small braking impact and in the shortest braking distance. Furthermore, since slippage between the sheave and the rope can be prevented, damage to the rope can be reduced.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing the construction of a lifting device as an example for explaining the braking device according to the present invention, and FIG. 2 is a diagram showing the construction of its mechanical system. Car 1, its drive device 3
, the control device 63 of the lifting device is the main component, and the control device of the braking device 9, which is the subject of the present invention. The car 1 and the counterweight 2 are connected by a main rope 6 stretched over a sheave 4 and a warping wheel 4a, and also connected by a compensating rope 7 stretched around a compensating pulley 5. The car 1 is supplied with necessary electricity and signals through a tail cord 8. The compensator pulley 5 and the weight 5a set an appropriate tension on the main rope 6 to prevent slippage between the sheave 4 and the rope 6. The governor 10 is driven by a governor rope 10c stretched between governor pulleys 10a and 10b and connected to the car 1, detects the speed of the car, especially abnormal speed, and sends a speed abnormality signal to the brake control device 60. The drive device 3 is composed of a motor 12, a reducer 11, a brake device 9, and a sheave 4, and the rotation of the motor 12 is controlled by the reducer 1.
1 and transmits the deceleration to the sheave 4, which drives the car 1 and the counterweight 2 via the main rope 6. The braking device 9 maintains the position of the car 1 when the lifting device is stopped and performs braking in an emergency. In this embodiment, a case is shown in which the reduction gear 11 is used, but there is also a case where the sheave 4 is directly driven by the low-speed motor 12. The elevator control device 63 centralizes and controls the elevator device, such as controlling the drive device 3 and displaying guidance on floors and cars in accordance with call signals from each floor 13, destination signals from the car 1, and the like. The brake control device 60 receives commands from the lift control device 63 and the governor 1.
The optimum braking force for the current operating condition is calculated from the signal from 0, the inertial mass of the car 1, the speed, etc., and the control valve 40 is controlled by converting it into the pressure of the fluid pressure cylinder of the braking device 9. The control valve 40 controls the fluid pressure from the fluid pressure unit 61 and supplies it to the fluid pressure cylinder of the braking device 9, and controls the pressure (
braking force). The emergency power source 62 drives the minimum equipment and equipment related to the safety of the lifting device, such as a brake control device, a control valve, and a fluid pressure unit, even in the event of a power outage or the like.

In normal operation, as shown in FIG. 3, the braking device 9 sets the braking force by stopping the lifting device and releases the braking force before starting the lifting device, and the speed control of the car 1 is entirely controlled by the motor. Do it at 12. When the car 1 starts running at a speed exceeding the rated speed while the lifting device is operating (while the braking device 9 is released) and the governor 10 detects a speed abnormality, or when the driving force of the motor 11 is lost due to a power outage, etc. When an abnormal condition occurs, the brake control device 60 sends a signal to the control valve 40 to immediately stop the lifting device. At this time, basket 1
The braking impact of rope 6 and sheave 4 should not be excessive.
The optimum braking force is calculated according to the current load condition (size of total inertial mass) and traveling speed, and the braking device 9 is controlled based on this. Therefore, as shown in Fig. 4, the braking device 9 has a braking force that can quickly generate an optimal braking force when an abnormality occurs, decelerate and stop the car 1, and more reliably maintain the position after the car has stopped. Occur.

FIG. 5 shows the structure of an embodiment of the braking device of the present invention. The drum 20 is fixed to a drive shaft 14 and driven clockwise or counterclockwise as the car 1 moves up and down. The braking device stand 15 and the fixed frame 16 are fixed to the base (not shown) of the driving device of the lifting device, and the shoes 22a, 22
The arms 21a and 21b having the arms 21a and 21b are connected to the brake device stand 15 with pins 21A and 21B. The arm 21 is connected to the rod 23a
, 23b and springs 24a, 24b to press against the fixed frame 16 side to generate a braking force. The movement of the piston 26 of the fluid pressure cylinder 25 is transmitted to the left and right arms 21 via links 28a and 28b. At this time, position adjusting portions 27a and 27b are provided to adjust the distance between the link and the arm so that the force of the piston is transmitted equally to the left and right arms. That is, the force of the piston 26 overcomes the force of the spring 24, pulling the shoe 22 away from the drum 20 and releasing the braking device. The fluid chamber 25 of the fluid pressure cylinder 25 via the flow path 51
By controlling the fluid pressure acting on a, the output of the piston 26, that is, the force that presses the shoe 22 against the drum 20, can be controlled, and the braking force can be controlled.

In the normal state of the lifting device, when the car is stopped, the force of the spring 24 moves the shoe 22 to the drum 20.
The movement of the drive shaft 14 is stopped by the friction force. High pressure fluid is supplied to the fluid pressure cylinder 25 in response to the operation command of the lifting device to push the piston 26, which overcomes the force of the spring 24 and separates the shoe 22 from the drum 20, thereby releasing the brake. Thereafter, the motor 11 accelerates, runs, and decelerates the car 1 in the upward or downward direction, and when the car 1 stops, the hydraulic cylinder 2
5 is discharged and the shoe 22 is pressed against the drum 20 by the force of the spring 24 to maintain the position of the drum 20. At this time, the set braking force is set to be large enough to safely brake the car 1 under any conditions, such as load imbalance or emergency braking.

When an abnormality occurs during operation of the lifting device (high pressure fluid is supplied to the fluid pressure cylinder 25 to release the braking device 9), if the load is large or small, the car may rise. As shown in FIG. 4, the braking force required of the braking device differs depending on whether the vehicle is moving or descending. The brake control device 60 determines the optimal braking force for the current operating condition, that is, the optimal pressure of the fluid pressure cylinder 25, based on signals from the lift control device 63 and the governor 10, and controls the fluid pressure control valve 4.
0, high pressure fluid is discharged while controlling the pressure of the fluid pressure cylinder 25, the shoe 22 is pressed against the drum 20 by the spring 24, and the car is braked by the frictional force between the two. This prevents slippage between the sheave 3 and the main rope 6 during braking, and the car 1 can be safely braked and stopped with a small braking impact and within the shortest braking distance.

[0013] In high-rise buildings with many floors, the distance of the car 1 is long. Therefore, with the aim of improving transportation efficiency, we decided to
The capacity of the train will be increased and high-speed operation will be achieved. This means that the weight of car 1 and counterweight 2 is larger than the load mass.
As the inertial mass of the main rope 6 increases, the weight of the main rope 6 and the weight of the compensating rope 7 that balances this increase even more. In other words, the increase in inertial mass is greater than the increase in unbalanced weight due to increase or decrease in the number of passengers, and the braking force required from the braking device 9 is also greater than the force required to statically hold the position of the car 1 while the car is running. The braking force for braking the inertial mass becomes relatively large. Therefore, if the braking force is entirely dependent on the pressing force of the spring 24, the spring will be large, and the device itself will also be large.
The installation space will also be larger.

FIG. 6 shows an embodiment in which the generation of the force that presses the shoe 22 against the drum 20 is shared between the spring 24 and the fluid pressure cylinder 29, and the fluid pressure cylinder 25 releases the force. The fluid pressure cylinders 29a, 29b are springs 24a, 24b.
Attach to arms 21a and 21b in parallel with pin 29A.
, 29B to the fixed frame 16. Fluid pressure cylinder 29
High-pressure fluid at a constant pressure is supplied to the rod-side fluid chamber through the flow path 52. As a result, the fluid pressure cylinders 29a, 2
9b is the piston 30a, 30b and the arm 21a, 21b
is pressed onto the drum 20. At this time, the spring 24 generates a force to hold the stopped car, etc. at the stopped position, and the fluid pressure cylinder 29 generates a force that is generated by subtracting the force generated by the spring 24 from the force necessary to brake the inertial mass while the car is running. generate force. For the same output, the fluid pressure cylinder is smaller than the spring, and the device can be made smaller. If the pressure in the rod side fluid chamber is controlled to be constant, the output will also be constant. A force greater than the sum of the forces of the spring 24 and the hydraulic cylinder 29 is generated in the fluid pressure cylinder 25, and the braking force is controlled by controlling the pressure in the fluid chamber 25a in the same manner as in the embodiment shown in FIG.

FIG. 7 shows an embodiment of a braking device having a structure in which an arm 22 is directly driven by a fluid pressure cylinder 25 provided with two pistons.The difference is that in the embodiment of FIG. In the embodiment of FIG. 7, the hydraulic cylinder 25 has two pistons 26a, 26b facing each other, and the cylinder body is fixed to the fixed frame 16, and the piston rod extends and contracts to both sides to directly drive the arms 21a and 21b. The force with which the shoe 22 is pressed against the drum 20 is controlled by the piston 2.
This is done by controlling the fluid pressure in the fluid chamber 25a between 6a and 26b. That is, when the pressure in the fluid chamber 25a is high, the output of the fluid pressure cylinder 25 becomes large, and the shoe 2
2 against the drum 20 becomes smaller, and the braking force becomes smaller. Conversely, if the pressure in the fluid chamber 25a is small, the braking force will be large. In this way, the method of setting and releasing the braking device is similar to the embodiment shown in FIG. Compared to FIG. 6, no link is required, so the structure is simpler, but on the other hand, the output of fluid pressure cannot be amplified.

In FIG. 8, the generation of the force that presses the shoe 22 against the drum 20 is shared by the pulling action of the spring 24 and the cylinder 25, and the force is released by the extending action of the fluid pressure cylinder 25. That is, this is an embodiment in which the fluid pressure cylinder 29 that presses the shoe 22 and the fluid pressure cylinder 25 that releases the braking device in the embodiment shown in FIG. 7 are combined into one fluid pressure cylinder 25. The fluid pressure cylinder 25 has two pistons, and a piston rod is connected to the arm 21 via adjustment parts 27a and 27b. Cylinder body is fixed frame 1
6, and the piston 26 expands and contracts on both sides to open the arm 2.
1 directly. The fluid chamber 25a between the pistons 26a and 26b receives high-pressure fluid with a controlled pressure through a flow path 51, and the fluid chambers 25b and 25c on the piston rod side receive fluid pressure controlled to a constant pressure through a flow path 52. supply. Fluid pressure is constantly applied to the fluid chambers 25b and 25c to press the shoe 22 against the drum 20, and a controlled fluid pressure is applied to the fluid chamber 25a to release the pressing force. Therefore, similarly to FIG. 7, the braking force can be controlled by controlling the pressure of the high-pressure fluid supplied to the fluid chamber 25a. In this embodiment, since the fluid pressure cylinder 29 is not required, the structure of the braking device 9 can be simplified.

FIG. 9 shows a single rod cylinder 25 and a shoe 22.
This is an embodiment in which the drum 20 is pressed against the drum 20 or separated from the drum 20. When a constant fluid pressure is applied to the fluid chamber 25b, the arm 21 is pulled, and the shoe 22 cooperates with the spring 24.
is pressed against the drum 20 and a controlled pressure fluid is supplied to the fluid chamber 25a, thereby reducing the previous pressing force. Therefore, similarly to FIGS. 6 to 8, the braking force can be controlled by controlling the pressure in the fluid chamber 25a.

10 and 11 show an embodiment applied to a disc-type braking device, FIG. 10 is a view seen from a direction perpendicular to the drive shaft 14, and FIG. 11 is a view seen from a direction parallel to the drive shaft 14. be. The disk 20 is fixed to the drive shaft 14 and the car 1
is driven clockwise or counterclockwise by rising or falling. The braking device stand 15 and the fixed frame 16 are fixed to the base (not shown) of the driving device of the lifting device, and the shoe 22a
, 22b have pins 21A, 2
1B is connected to the brake device stand 15, and the arms 21a, 21
b is pressed toward the fixed frame 16 by rods 23a, 23b and springs 24a, 24b. That is, the shoe 22 is pressed against the disk 20 to generate braking force. The movement of the piston 26 of the fluid pressure cylinder 25 is controlled by links 28a and 28.
It is transmitted to the left and right arms 21a and 21b via b. The fluid pressure cylinder 25 is a single rod cylinder that supplies high pressure fluid to the fluid chamber 25b to press the shoe 22 against the disk 20 in cooperation with the spring 24, and supplies high pressure fluid to the fluid chamber 25a to release the pressing force. do. In other words, the force of the fluid pressure cylinder 25 and the spring 24 causes the shoe 22 to move toward the disk 2.
0 to set the braking force, and the hydraulic cylinder 25
The force overcomes the force of the spring 24 and moves the shoe 22 to the disk 2.
Pull it away from 0 to release the braking force. By controlling the fluid pressure acting on the fluid chamber 25a of the fluid pressure cylinder 25 via the flow path 51, the output of the piston 26 can be controlled, and the braking force generated between the shoe 22 and the drum 20 can be controlled. In this example, a disk with lower inertia than a drum is used, so
Braking force can be reduced.

FIG. 12 is an embodiment in which the two springs used in the embodiment shown in FIG. 10 are reduced to one. That is, when pressing the left and right shoes 22a, 22b against the disk 20, the left and right arms 21a, 21b are attracted by a single spring 23, and the output of the fluid pressure cylinder 25 is further applied. Conversely, when releasing the braking device, the links 28a, 28
The left and right arms 21a,
Push open 21b. The operation and force control are the same as in the embodiment shown in FIG. 10, so their explanation will be omitted here. In this embodiment, by using only one spring 24, the spring force that presses the left and right arms can be made uniform, and adjustment can be facilitated.

FIG. 13 shows the fluid chamber 25 of the fluid pressure cylinder 25.
An example of a fluid pressure circuit for controlling the pressure of a is shown. The fluid pressure control device includes a fluid pressure control valve 40, a filter 47, a motor 41, a fluid pressure pump 42, a relief valve 43, and a check valve 4.
4, an accumulator 45, a pressure switch 46, and a fluid tank 48. A hydraulic pump 42 driven by a motor 41 makes the working fluid in a fluid tank 48 high pressure and stores it in an accumulator 45 . At this time, the fluid pressure pump 42 is operated and stopped using the signal from the pressure switch 46, and the pressure of the high pressure fluid stored in the accumulator 45 is kept almost constant at all times. The filter 47 is used to remove foreign matter in the fluid, the relief valve 43 is used to prevent the fluid pressure pump outlet from becoming abnormally high pressure, and the check valve 44 is used to prevent high pressure fluid from flowing in the pump direction even if the fluid pressure pump 42 is stopped. Used to prevent backflow. The control valve 40 is connected to the flow path 51
It communicates with the fluid chamber 25a of the fluid pressure cylinder 25 of the above-mentioned embodiment, and under normal conditions, the fluid chamber 25a is opened and the pressure of the high-pressure fluid stored in the accumulator 45 is released according to a command from the brake control device 60. The fluid is supplied to the fluid chamber 25a under control, and its pressure is controlled.

That is, in normal operation of the lifting device, upon startup, the high-pressure fluid of the accumulator 45 is supplied to the fluid chamber 25a in response to a command from the brake control device 60 to release the brake device, and when the car 1 stops, the fluid chamber The high pressure fluid at 25a is discharged and the braking device is set. At this time, a large flow rate is required in order to quickly release and set the brake system. If an emergency situation such as a power outage occurs while the elevating device is running, the brake control device 60 takes into account the size of the inertial mass and the traveling speed at this time, and applies the optimal braking force, that is, applies the shoe 22 to the drum or disk 20. The pressing force is calculated, converted into the pressure of the fluid pressure cylinder 25, and a command is issued to the fluid pressure control valve 40. The fluid pressure control valve 40 controls the pressure by discharging the high pressure fluid from the fluid chamber 25a in accordance with a command from the brake control device 60. At this time, since the volume of the fluid chamber 25a is small, the pressure in the fluid chamber 25a will drop significantly even if a small amount of fluid is discharged. Take control. This makes it possible to control the braking force as described above. In this way, the control valve 40 is required to perform both flow control during normal times and pressure control during emergencies.

FIG. 14 shows the characteristics of the flow rate control valve 40 according to the present invention, with the horizontal axis representing the command signal and the vertical axis representing the controlled flow rate and control pressure. When the command is 0, the cylinder and the tank are communicated, and when the command is at the rated value e0, the high pressure and the cylinder are communicated. Set e1 and e2 smaller than e0 (e
1<e2), the range between 0 and e1 and between e2 and e0 is the flow rate control range, and the range between e1 and e2 is the pressure control range. An example of a specific structure of the control section of the control valve 40 is shown in FIG.
Shown below. 55 is a sleeve, 56 is a notch 56a, 56b
The control valve has fluid chambers 55a, 55b,
55c, which communicate with the high-pressure flow path 53, the flow path 51 to the cylinder 25, and the flow path 54 to the tank 48, respectively. The spool 56 may be driven mechanically, electrically, electromagnetically, or hydraulically as long as a sufficient response can be obtained in controlling the flow rate and pressure. The figure (a) explains the spool position and fluid flow state when the command is 0, (b) when the command is (e1+e2)/2, and (c) when the command is e0. . When the command is 0 (a
) has a flow path 51 (cylinder port) and a low pressure side flow path 54 (
tank port) communicates with each other to release the fluid chamber 25a of the cylinder 25 to low pressure. When the command becomes large, the spool 56
moves to the right, the opening area between fluid chambers 55b and 55c becomes smaller, and the flow rate becomes smaller. When the signal becomes e1, the end surface 56d of the left spool land is connected to the fluid chambers 55b and 5.
5c and communicate slightly with the notch 56b,
In the right spool land, the notch 56a is not opened. At this time, the flow rate decreases as the displacement of the spool 56 increases. If the command increases further, the notch 5
6a is also opened, and the flow path 51 is connected to the low pressure side flow path 54 and the high pressure side flow path 5.
3 and communicates with each other in a narrow area at the same time. The command is (e1+e2
)/2, in (b), the slight communication areas of the notches 56a and 56b of the left and right spool lands are equal, and the inflow from the high pressure side flow path 53 to the flow path 51 and the inflow to the low pressure side flow path 54. The outflow becomes equal and the pressure becomes 1/2 of the high pressure side fluid pressure. Furthermore, the command becomes larger and becomes e2, and the spool 56
moves to the right, the notch 56b of the left spool land
is closed, and the end face 56c of the right spool land is opened, allowing high-pressure fluid to flow into the flow path 51. In other words, the command is e1
Since the fluid is controlled by the notches 56a and 56b between and e2, the pressure can be controlled with high precision although the flow rate is small. When the signal further increases and the spool 56 is displaced, the opening area also becomes larger and the flow rate increases, and when it reaches e0, the fluid chamber 55
The opening area between a and 55b becomes maximum and the flow rate becomes the rated flow rate. Therefore, the flow rate control and pressure control shown in FIG. 14 can be executed.

FIG. 16 shows a fluid pressure circuit that controls the fluid pressures of the fluid pressure cylinder 25 and the fluid pressure cylinder 29 at the same time, or the fluid pressures of the fluid chambers 25a, 25b, and 25c of the fluid pressure cylinder 25. The discharge fluid of the fluid pressure pump 42 is stored in the accumulator 45, and the flow rate or pressure is controlled by the control valve 40 to control the displacement or output of the fluid pressure cylinder 25, as in the embodiment shown in FIG. Further, the discharge fluid of the fluid pressure pump 42 is branched and guided to the control valve 49, and the high pressure fluid controlled by this is supplied to the fluid pressure cylinder 29 or the fluid chambers 25b and 25c of the fluid pressure cylinder 25 through the flow path 52. In addition to the force of the spring 24, the arm 21 is pushed toward the drum or disk. An accumulator 5 is provided in the flow path 52.
0 is provided so that even if the fluid pressure cylinder 29 or 25 operates, the pressure in the fluid chamber will not fluctuate and the force pushing the arm will not fluctuate. As a result, the fluid pressure cylinder 29
, or 25 cooperates with the spring 24 to press the arm 21 against the drum or disk 20 with a substantially constant force, and releases and sets the braking device 9 by controlling the pressure in the fluid chamber 25a of the fluid pressure cylinder 25. , braking force can be controlled at high speed and with high precision.

FIG. 17 shows yet another embodiment of a fluid pressure circuit. Fluid chamber 25b, 2 of fluid pressure cylinder 29 or 25
5c is supplied with high-pressure fluid stored in the accumulator 45 to press the arm 21 against the drum or disk 20 with a constant force, and the pressure in the fluid chamber 25a is controlled by the control valve 40 to release the braking device 9. Settings, braking force control, etc. are performed quickly and with high precision. Compared to the example shown in FIG.
This configuration simplifies the circuit by omitting the control valve 49 and accumulator 50. Therefore, the operation and effect are similar to the embodiment of FIG. 16.

FIG. 18 shows yet another embodiment of a fluid pressure circuit. Hydraulic cylinders 25, 29 shown in FIGS. 6 to 12
All of these controls are performed by a rectangular control valve 40. The discharge flow rate of the fluid pressure pump 42 is stored in the accumulator 45, and pressure-controlled fluid is supplied to the control ports 51, 52 of the control valve 40 to control the output and speed of the fluid pressure cylinders 25, 29. In this embodiment, the hydraulic cylinder 25 applies a force to separate the arm 21 from the drum or disk 20, and at the same time, the cylinder 29 or 25 applies a force to separate the arm 21 from the drum or disk 20.
Alternatively, the force with which the disk 20 is pressed is controlled. Therefore, when the arm 21 is separated from the drum (disc) 20 by the hydraulic cylinder 25, the cylinder 29 or 2
5, the force for pressing the arm 21 against the drum (disc) 20 can be reduced, and the hydraulic cylinder 25 can be made smaller, that is, the hydraulic device including the fluid pressure control valve 40 can be made smaller.

[0026]

[Effects of the Invention] According to the present invention, small size, large capacity, high response,
In addition, a high-performance and safe braking device can be obtained that can arbitrarily control its braking force and can be operated with a small-capacity emergency power supply even in the event of a power outage. Therefore, during normal times, it is possible to reliably maintain the position of the load such as a car, and in an emergency, it is possible to generate an optimal braking force according to the load and speed of the car, etc., and to achieve a small braking impact and the shortest braking distance.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a lifting device.

FIG. 2 is an explanatory diagram showing an example of a mechanical system of a lifting device.

FIG. 3 is an explanatory diagram of the operation of the braking device under normal conditions.

FIG. 4 is an explanatory diagram of the operation of the braking device during emergency braking.

FIG. 5 is an explanatory diagram showing an embodiment of a braking device according to the present invention.

FIG. 6 is an explanatory diagram showing a second embodiment of the braking device according to the present invention.

FIG. 7 is an explanatory diagram showing a third embodiment of the braking device according to the present invention.

FIG. 8 is an explanatory diagram showing a fourth embodiment of the braking device according to the present invention.

FIG. 9 is an explanatory diagram showing a fifth embodiment of the braking device according to the present invention.

FIG. 10 is an explanatory diagram showing a sixth embodiment of the braking device according to the present invention.

FIG. 11 is an explanatory diagram of the embodiment of FIG. 10 viewed from the drive shaft direction.

FIG. 12 is an explanatory diagram showing a seventh embodiment of the braking device according to the present invention.

FIG. 13 is a system diagram of an embodiment of a fluid pressure circuit that drives a fluid pressure cylinder according to the present invention.

FIG. 14 is an explanatory diagram of characteristics of a control valve.

FIG. 15 is an explanatory diagram of a control section of a control valve.

FIG. 16 is a system diagram of a second embodiment of another fluid pressure circuit for driving a fluid pressure cylinder according to the present invention.

FIG. 17 is a system diagram of a third embodiment of another fluid pressure circuit for driving a fluid pressure cylinder according to the present invention.

FIG. 18 is a system diagram of a fourth embodiment of another fluid pressure circuit for driving a fluid pressure cylinder according to the present invention.

[Explanation of symbols]

14... Drive shaft, 15... Brake device stand, 16... Fixed frame, 20
...Drum or disk, 21...Arm, 21A, 21
B, 23A, 23B...Pin, 22...Shoe, 23...Rod, 24...Spring, 25...Fluid pressure cylinder, 26...Piston, 27...Position adjustment, 28...Link, 28A, 28B...
pin.

Claims (1)

[Claims] 1. A braking device comprising a drum or a disk, a shoe pressed against the drum, an arm that presses the shoe against the drum or disk, and a control device that controls the operation of the arm, which uses a spring and a fluid pressure cylinder in combination. A braking device characterized in that the braking force is controlled by pressing an arm against the drum or disk and controlling the pressure of the fluid pressure cylinder.