JP3768005B2 - Method and device for correcting stroke position of multistage cylinder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for correcting the stroke position of a multistage cylinder.
[0002]
[Prior art]
Conventionally, multistage cylinders (telescopic cylinders) are used for hydraulic elevators.
[0003]
FIG. 7 is a diagram illustrating an example of the configuration of the hydraulic elevator 1.
In FIG. 7, a pit PI is provided on the floor surface FL, and a hoistway WY is formed by the building CT above the pit PI. A multistage cylinder CY is installed in the pit PI, and a basket CG is attached to the tip of the rod. The cage CG moves up and down in the hoistway WY by the expansion and contraction of the multistage cylinder CY.
[0004]
The pit PI is provided with a plurality of buffer springs SP in order to ensure safety in the event of an emergency. The buffer spring SP is provided so that its uppermost portion is positioned slightly lower than the floor surface FL so that the buffer spring SP does not act when the cage CG is normally operated.
[0005]
FIG. 8 is a cross-sectional view showing an example of the structure of the multistage cylinder CY2.
A multistage cylinder CY2 shown in FIG. 8 is a two-stage multistage cylinder. A first stage piston 62 is provided to slide on the inner peripheral surface of the basic cylinder tube 61. A hollow first-stage rod 63 integrated with the first-stage piston 62 is used as a second-stage cylinder tube, and a second-stage piston 64 and a second-stage rod 65 are placed in the second-stage cylinder tube. A plurality of cylinders are configured to be nested.
[0006]
The first stage rod 63 is provided with communication holes 71, 71 for communicating the outer peripheral side and the inner peripheral side. The second-stage piston 64 is provided with a communication hole 72 that allows the fluid chambers CB13, 14 on both sides thereof to communicate with each other. The basic cylinder tube 61 is provided with a port PT for supplying and discharging pressurized fluid.
[0007]
The first stage piston 62 is provided with a check valve 75 in a direction of free flow from the lower fluid chamber CB11 toward the upper fluid chamber CB13. The check valve 75 is mechanically operated when the first-stage piston 62 and the first-stage rod 63 are most contracted, and a free flow is generated between the fluid chambers CB11 and 13 on both sides of the first-stage piston 62. Communicate so that
[0008]
The pressurized fluid flowing in from the port PT flows into the fluid chamber CB11 on the lower side of the first stage piston 62, and pushes the piston 62 upward. As a result, the piston 62 moves upward.
[0009]
Since the volume of the fluid chamber CB12 is reduced by the upward movement of the first stage piston 62, the pressurized fluid in the fluid chamber CB12 flows into the fluid chamber CB13 through the communication holes 71 and 71, and thereby the second stage piston 62 is moved. The piston 64 is pushed up.
[0010]
Since the volume of the fluid chamber CB14 decreases due to the upward movement of the second-stage piston 64, the pressurized fluid in the fluid chamber CB14 flows into the fluid chamber CB13 through the communication hole 72.
[0011]
Usually, the value of the effective pressure receiving area of each piston 62, 64 is designed so that the first stage rod 63 and the second stage rod 65 move at the same relative speed in synchronization with each other. The multistage cylinder CY2 designed as such is called a constant speed multistage cylinder.
[0012]
In the multistage cylinder CY <b> 2, the basic cylinder tube 61 and the piston 62 are sealed with a packing attached to the piston 62. For this packing, a slipper seal type is often used to reduce sliding resistance. Since such a packing has a lot of internal leakage, the pressurized fluid leaks from the fluid chamber CB12 and enters the fluid chamber CB11, and the total amount of the pressurized fluid in the fluid chambers CB12, 13, 14 decreases with long-term use. Therefore, the second-stage piston 64 does not rise to the most extended position, and a step is generated between the first-stage rod 63 and the second-stage rod 65.
[0013]
However, by moving the first stage piston 62 to the most contracted position, the check valve 75 is mechanically operated, and a part of the pressurized fluid in the fluid chamber CB11 is sucked into the fluid chambers CB12, 13, and 14. As a result, initialization is performed and the step is eliminated.
[0014]
FIG. 8 shows the two-stage multistage cylinder CY2, but in the case of the three-stage or more multistage cylinder CY, a plurality of ones having the same structure as the first stage piston 62 and the first stage rod 63 are provided. Will be provided. The structure and usage of such a multistage cylinder CY is known from Japanese Patent Laid-Open No. 5-330762.
[0015]
[Problems to be solved by the invention]
As shown in FIG. 7, the basket CG uses the position of the floor surface FL on the first floor as the lower limit position, sets the position of the upper floor, for example, the floor surface of the second floor or the third floor as the upper limit position, and lower limit position in normal operation. And between the upper limit position. The multi-stage cylinder CY performs expansion / contraction driving in the middle between all strokes. That is, in normal operation, the multistage cylinder CY does not descend to the most contracted position. For this reason, initialization is not performed in normal operation, and therefore a level difference is generated as it is used.
[0016]
Conventionally, in order to eliminate this step, the buffer spring SP is removed about every month, the multistage cylinder CY is once lowered to the most contracted position, and the built-in check valve 75 is operated. Thus, the amount of pressurized fluid at each stage is corrected, and the stroke position of each stage is corrected. Thereafter, the buffer spring SP is attached again.
[0017]
As described above, conventionally, it is necessary to periodically remove and attach the buffer spring SP in order to correct the stroke position of the multistage cylinder CY, which is very troublesome and requires a lot of time and labor. It was necessary.
[0018]
The present invention has been made in view of the above-described problems, and provides a method and apparatus that can easily correct the stroke position of a multistage cylinder without performing a troublesome operation such as removing a buffer spring. With the goal.
[0019]
[Means for Solving the Problems]
In the method according to the first aspect of the present invention, the first stage piston is provided so as to slide on the inner peripheral surface of the basic cylinder tube, and the hollow first stage rod integrated with the first stage piston is provided. Each of the rods of a multistage cylinder in which a plurality of cylinders are nested such that a second stage cylinder tube is provided, and a second stage piston and a second stage rod are provided in the second stage cylinder tube. A method for correcting a stroke position, wherein a fluid is supplied to or discharged from a lower fluid chamber of a first stage piston to position a stroke position of a first stage rod at a predetermined intermediate position. step second step of moving the second and subsequent stages of the rod by discharge the lower fluid chamber of the fluid of the second stage of the piston to the most retracted position, respectively, the second and subsequent stages of rod extension Third step of supplying fluid to the lower side of the fluid chamber of the second-stage piston to move in the direction, and the stroke position of the second stage of the rods, the stroke position of the rod of the first stage which is positioned And a fourth step of stopping the supply of the pressurized fluid when the same stroke position is reached.
[0020]
In the method according to the second aspect of the present invention, in the fourth step, the supply of the pressurized fluid is stopped by a detection signal of a second sensor that detects the stroke position of the second stage rod.
[0021]
According to a third aspect of the present invention, in the fourth step, the replenishment of the pressurized fluid is stopped based on a signal from a flow rate detection device that detects the replenishment amount of the pressurized fluid.
According to a fourth aspect of the present invention, the first sensor for detecting that the stroke position of the first stage rod is a predetermined intermediate position, and the stroke position of the second stage rod are detected by the first sensor. A second sensor for detecting that the stroke position is the same as the stroke position of the first-stage rod, and a pressurized fluid supply device for supplying pressurized fluid so that the second-stage and subsequent rods move in the extending direction; Then, the stroke position of the first stage rod is positioned at a position detected by the first sensor, the second stage and subsequent rods are moved to the most contracted positions, and the second sensor detects the second stage rod. And a control device that performs control so that the pressurized fluid is replenished by the pressurized fluid replenishing device.
[0022]
According to a fifth aspect of the present invention, there is provided a first sensor for detecting that a stroke position of the first stage rod is a predetermined intermediate position, and a pressure so that the second stage and subsequent rods move in the extending direction. A pressurized fluid replenishing device for replenishing fluid, a flow rate detecting device for detecting a replenishing amount of the pressurized fluid, and a stroke position of the first stage rod at a position where the first sensor detects, Each of the rods is moved to the most contracted position, and the pressurized fluid is supplied by the pressurized fluid supply device so that the second-stage rod extends to the same stroke position as the stroke position of the first-stage rod detected by the first sensor. And a control device that controls to perform the replenishment.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a hydraulic circuit diagram of a hydraulic elevator 1 to which a correction apparatus according to the present invention is applied, and FIG. 2 is a cross-sectional view showing a main part of a multistage cylinder CY1 used in the hydraulic elevator 1 of FIG.
[0024]
In the present embodiment, the multistage cylinder CY1 is a three-stage constant speed multistage cylinder. Hydraulic pressure is used as the pressurized fluid.
In FIG. 2, the multistage cylinder CY <b> 1 is provided with a first stage piston 42 so as to slide on the inner peripheral surface of the basic cylinder tube 41. A hollow first-stage rod 43 integrated with the first-stage piston 42 is used as a second-stage cylinder tube, and a second-stage piston 44 and a second-stage rod 45 are placed in the second-stage cylinder tube. Is provided. Further, a second-stage rod 45 is used as a third-stage cylinder tube, and a third-stage piston 46 and a third-stage rod 47 are provided. A basket CG is attached to the tip of the third stage rod 47.
[0025]
A base cover 40 is attached to the lower end surface of the basic cylinder tube 41, and a block 40 a is attached to the center of the base cover 40. The base cover 40 is fixed to the concrete base in the pit PI.
[0026]
A rod cover 41a is attached to the upper end of the basic cylinder tube 41, a rod cover 43a is attached to the upper end of the first stage rod 43, and a rod cover 45a is attached to the upper end of the second stage rod 45 (see FIG. 1). ). The basic cylinder tube 41 is provided with a port 40b for supplying and discharging pressure oil for normal operation and a port 40c for supplying and discharging pressure oil for correction operation.
[0027]
The first stage piston 42 and the first stage rod 43 have a communication hole 51, the second stage piston 44 and the second stage rod 45 have a communication hole 52, and the third stage piston 46 has a communication hole 53. Are provided. These communication holes 51, 52, and 53 connect the fluid chamber CB2 and the fluid chamber CB3, the fluid chamber CB4 and the fluid chamber CB5, and the fluid chamber CB5 and the fluid chamber CB6, respectively.
[0028]
The first stage piston 42 is provided with a check valve 55 and a permanent magnet 58, and the second stage piston 44 is provided with a check valve 56. Each piston 42, 44, 46 is provided with a seal and a sliding member, respectively.
[0029]
A position sensor LS1 that outputs a detection signal in response to the permanent magnet 58 is provided on the outer peripheral surface of the basic cylinder tube 41. The position sensor LS1 is arranged to detect a predetermined stroke position with respect to the first stage rod 43.
[0030]
As the position sensor LS1, various sensors incorporating a Hall element, a magnetoresistive element, or a reed switch that operate by detecting the magnetic field of the permanent magnet 58 can be used. In this case, stainless steel, which is a non-magnetic material, is desirable as the material of the basic cylinder tube 41, but even a magnetic steel material can be detected.
[0031]
As shown in FIG. 1, in order to detect the stroke position of the second stage rod 45, a position sensor LS2 operated by a yoke 45b attached to the rod cover 45a is provided. The position sensor LS2 is a position where the stroke position of the second stage rod 45 is separated from the first stage rod 43 by the same stroke as the stroke position of the first stage rod 43 detected by the position sensor LS1. Is arranged to detect.
[0032]
As the position sensor LS2, a mechanically operated limit switch, proximity sensor, photo sensor, magnetic proximity sensor, or the like is used.
In FIG. 1, the hydraulic circuit includes a main hydraulic circuit MC for normal operation as a hydraulic elevator and an auxiliary hydraulic circuit AC for correcting the stroke position of the multistage cylinder CY.
[0033]
The main hydraulic circuit MC includes a main pump 11 driven by a motor (not shown), an elevator valve device 12 that includes various valves and controls the multistage cylinder CY1 to raise and lower the cage CG, a filter 19, a tank 21, and a port 40b. The main pipe 31 is connected to the. Since the main hydraulic circuit MC itself is known, detailed description thereof is omitted here.
[0034]
The auxiliary hydraulic circuit AC includes an auxiliary pump 13 driven by a motor (not shown), a relief valve 14, a check valve 15, a switching valve 16, a pressure sensor 17, a switching valve 18, a filter 20, and an auxiliary pipeline connected to the port 40c. 32 or the like.
[0035]
The discharge flow rate of the auxiliary pump 13 is, for example, about 30 liters / minute, which is about 1 which is enough for the main pump 11. The switching valve 18 switches the pressure oil sent from the auxiliary pump 13 between the auxiliary line 32 and the main line 31. When the switching valve 16 is turned on, the pressure oil sent from the auxiliary pump 13 and the pressure oil flowing out from the auxiliary pipe 32 or the main pipe 31 are returned to the tank 21.
[0036]
In order to control the correction operation of the multistage cylinder CY in the hydraulic elevator 1 and to perform overall control, a control device 30 is provided.
Next, a method for correcting the stroke position of the multistage cylinder CY1 will be described.
[0037]
3 and 4 are diagrams showing the state of the rod during the correction operation, and FIG. 5 is a flowchart showing the correction operation. In FIGS. 3 and 4, detailed portions are not shown.
[0038]
When executing the correction operation, the operation of the main hydraulic circuit MC is stopped.
It is possible to start from a state in which the cage CG is in the normal operation position, that is, between the lower limit position and the upper limit position, and the rods 43, 45, 47 of the multistage cylinder CY1 are in arbitrary positions. First, with the switching valve 18 turned off, the auxiliary pump 13 is driven to supply the pressure oil from the port 40b, or the switching valve 16 is turned on to allow the pressure oil to flow out from the port 40b. 43 is moved. When the position sensor LS1 detects the position of the first stage rod 43, the auxiliary pump 13 is stopped or the switching valve 16 is turned off to position the first stage rod 43 (step # 1). At this time, the position of the first stage rod 43 is as shown in FIG.
[0039]
Next, in a state where the auxiliary pump 13 is stopped, the switching valve 18 and the switching valve 16 are turned on, and the pressure oil in the fluid chambers CB2 and CB3 is discharged from the port 40c. As a result, the second-stage and third-stage rods 45 and 47 move downward while the first-stage rod 43 is stopped, so that they are lowered to the most contracted position, that is, the bottom position (step # 2). ). The bottom position is detected when the detected pressure of the pressure sensor 17 is reduced to almost zero, and the switching valve 18 and the switching valve 16 are turned off by the detection signal. The state at this time is shown in FIG.
[0040]
The third-stage piston 46 and the rod 47 are lowered to the bottom position when the check valve 56 is mechanically operated to become a free flow.
Then, the switching valve 18 is turned on, the auxiliary pump 13 is driven, and pressure oil is supplied from the port 40c. As a result, the pressure oil flows into the fluid chambers CB2 and CB3 and moves the second-stage piston 44 and rod 45 upward. Along with this, the third-stage piston 46 and the rod 47 are moved upward synchronously (step # 3).
[0041]
When the position sensor LS2 detects the yoke 45b, the switching valve 18 is turned off and the auxiliary pump 13 is stopped (step # 4). This completes the correction operation. The state at this time is shown in FIG.
[0042]
As described above, when the correction operation is executed, the first stage rod 43 may be lowered to the stroke position detected by the position sensor LS1 without being lowered to the lowest position, so that the buffer spring SP is not removed. Since the bottom of the basket CG does not interfere with the buffer spring SP, the operation can be performed easily and quickly.
[0043]
Such a correction operation can be performed automatically. For example, at the night when the use of the hydraulic elevator 1 is low, it is possible to automatically execute the correction operation as described above after confirming that there is no person in the basket CG. Confirmation that there is no person in the cage CG is that no operation is detected between the time when the doors DRi and DRo are closed and a predetermined time elapses, or the camera installed in the cage CG This is possible because the person is not projected for a predetermined time. It is also possible to confirm using an ultrasonic sensor or an infrared sensor.
[0044]
The automatic correction operation may be performed at an appropriate interval such as once a week or once a month. It is also possible to detect a shift in the stroke position of the multistage cylinder CY1 by detecting a time shift in detection by the position sensors LS1 and LS2 and automatically execute it when the shift exceeds a predetermined value. It is. In this case, during normal operation of the hydraulic elevator 1, the deviation may be detected when the interval between the ON timings of the position sensors LS1 and LS2 exceeds a predetermined time. In this manner, the position sensors LS1 and 2 and the timer can provide a diagnosis function. In this case, an indicator lamp is provided on the display panel of the control device 30 when the result of diagnosis is in a state that requires correction, regardless of whether the correction operation is automatically performed. Just keep it.
[0045]
Further, the auxiliary hydraulic circuit AC can be used for minute movement of the hydraulic elevator 1. That is, by driving the auxiliary pump 13 with the switching valve 18 turned off, the multistage cylinder CY can be driven at a low speed, and, for example, the basket CG with the doors DRi and DRo being opened can be opened. The stop position of the CG can be finely adjusted.
[0046]
Next, a hydraulic elevator 1A according to another embodiment will be described.
FIG. 6 is a hydraulic circuit diagram of a hydraulic elevator 1A to which a correction apparatus according to another embodiment of the present invention is applied.
[0047]
The difference between the hydraulic elevator 1A and the hydraulic elevator 1 described above is that the position sensor LS2 is omitted and an integrated flow sensor 23 is provided instead. The control device 30 is provided with a comparator (not shown) that outputs a control signal when the output of the flow sensor 23 becomes larger than a set value.
[0048]
That is, in the hydraulic elevator 1A, instead of detecting the stroke position of the second stage rod 45 by the position sensor LS2, the integrated flow rate of the pressure oil supplied to the port 40c is detected by the flow sensor 23, and the integrated flow rate is calculated. It is assumed that the second stage rod 45 has reached a predetermined stroke position by reaching the set value.
[0049]
According to the hydraulic elevator 1A, since it is not necessary to provide the position sensor LS2, it is not necessary to provide the yoke 45b or the like, and the configuration can be simplified.
In the above embodiment, the configuration, structure, shape, material, operation content, operation timing, etc. of the whole or each part of the multistage cylinder CY1, the auxiliary hydraulic circuits AC, AC1, and the hydraulic elevators 1, 1A are within the spirit of the present invention. Can be changed accordingly.
[0050]
【The invention's effect】
According to the present invention, it is possible to easily correct the stroke position of the multi-stage cylinder without performing a troublesome operation such as removing the buffer spring.
[0051]
According to the third and fifth aspects of the present invention, since it is not necessary to provide a second sensor for detecting the stroke position of the second stage rod of the multistage cylinder, the apparatus can be simplified.
[Brief description of the drawings]
FIG. 1 is a hydraulic circuit diagram of a hydraulic elevator to which a correction apparatus according to the present invention is applied.
FIG. 2 is a cross-sectional view showing a main part of a multistage cylinder used in the hydraulic elevator shown in FIG.
FIG. 3 is a diagram illustrating a state of a rod during a correction operation.
FIG. 4 is a diagram illustrating a state of a rod during a correction operation.
FIG. 5 is a flowchart showing a correction operation.
FIG. 6 is a hydraulic circuit diagram of a hydraulic elevator to which a correction device according to another embodiment of the present invention is applied.
FIG. 7 is a diagram illustrating an example of a configuration of a hydraulic elevator.
FIG. 8 is a cross-sectional view showing an example of the structure of a multistage cylinder.
[Explanation of symbols]
1, 1A Hydraulic elevator 13 Auxiliary pump 18 Switching valve 23 Flow rate sensor (flow rate detection device)
30 control device 41 basic cylinder tube 42 1st stage piston 43 1st stage rod 44 2nd stage piston 45 2nd stage rod 46 3rd stage piston 47 3rd stage rod AC Auxiliary hydraulic circuit (pressure fluid supply device )
LS1 Position sensor (first sensor)
LS2 position sensor (second sensor)

Claims (5)

A first stage piston is provided so as to slide on the inner peripheral surface of the basic cylinder tube, and a hollow first stage rod integrated with the first stage piston is used as a second stage cylinder tube. A method of correcting the stroke position of each rod of a multistage cylinder in which a plurality of cylinders are nested, such that a second stage piston and a second stage rod are provided in a stage cylinder tube,
A first step of positioning the stroke position of the first stage rod at a predetermined intermediate position by supplying or discharging fluid to a fluid chamber below the first stage piston ;
A second step of moving the second and subsequent rods to their most contracted positions by discharging the fluid in the lower fluid chamber of the second piston ;
A third step of supplying pressurized fluid to the fluid chamber below the second-stage piston so that the second-stage and subsequent rods move in the extending direction; and
The fourth step of the stroke position of the second stage of the rod, stops supply of the fluid when a position of the same stroke as the stroke position of the first stage of rods positioned,
A method for correcting the stroke position of a multi-stage cylinder. In the fourth step, the supply of the pressurized fluid is stopped by the detection signal of the second sensor that detects the stroke position of the second stage rod.
The method for correcting the stroke position of a multistage cylinder according to claim 1. In a fourth step, based on a signal from a flow rate detection device that detects the replenishment amount of the pressurized fluid, the replenishment of the pressurized fluid is stopped.
The method for correcting the stroke position of a multistage cylinder according to claim 1. A first stage piston is provided so as to slide on the inner peripheral surface of the basic cylinder tube, and a hollow first stage rod integrated with the first stage piston is used as a second stage cylinder tube. A device for correcting the stroke position of each rod of a multistage cylinder in which a plurality of cylinders are nested, such that a second stage piston and a second stage rod are provided in a stage cylinder tube,
A first sensor for detecting that the stroke position of the first stage rod is a predetermined intermediate position;
A second sensor for detecting that the stroke position of the second stage rod is the same stroke position as the stroke position of the first stage rod detected by the first sensor;
A pressurized fluid replenishing device that replenishes the pressurized fluid so that the second and subsequent rods move in the extending direction;
Positioning the stroke position of the first stage rod at the position detected by the first sensor, moving the second stage and subsequent rods to the most contracted positions, respectively, until the second sensor detects the second stage rod A control device that performs control so as to supply pressurized fluid by the pressurized fluid supply device;
An apparatus for correcting the stroke position of a multi-stage cylinder, comprising: A first stage piston is provided so as to slide on the inner peripheral surface of the basic cylinder tube, and a hollow first stage rod integrated with the first stage piston is used as a second stage cylinder tube. A device for correcting the stroke position of each rod of a multistage cylinder in which a plurality of cylinders are nested, such that a second stage piston and a second stage rod are provided in a stage cylinder tube,
A first sensor for detecting that the stroke position of the first stage rod is a predetermined intermediate position;
A pressurized fluid replenishing device that replenishes the pressurized fluid so that the second and subsequent rods move in the extending direction;
A flow rate detection device for detecting the replenishment amount of the pressurized fluid;
The stroke position of the first-stage rod is positioned at a position detected by the first sensor, the second-stage and subsequent rods are moved to the most contracted positions, and the second-stage rod is detected by the first sensor. A control device that controls to replenish the pressurized fluid by the pressurized fluid replenishing device so as to extend to a position corresponding to the same stroke as the stroke position of the first stage rod ;
An apparatus for correcting the stroke position of a multi-stage cylinder, comprising:

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