JP2006044939A - Hydraulic circuit of hydraulic elevator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic circuit of a hydraulic elevator, stably liftable, without causing swinging, when getting in and out of the elevator. <P>SOLUTION: This hydraulic circuit of the hydraulic elevator reduces motive power of a driving source by setting hydraulic pressure of a cylinder for lifting a person and/or cargo loading cage to hydraulic pressure of about 1/2 by adding a balance weight. This hydraulic circuit has a double-acting cylinder or a ram type cylinder for setting its internal pressure to holding pressure in maximum loading weight or no-load, desirably, to predetermined pressure or more, less than the holding pressure, at least when boarding on a cage and/or when loading a cargo. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hydraulic circuit of a hydraulic elevator, and more particularly, to a hydraulic circuit of a hydraulic elevator that prevents shaking during boarding and loading.

  2. Description of the Related Art Conventionally, hydraulic jacks have been used in which a ram projects from a cylinder tube to raise and lower a cage. This hydraulic jack requires a hydraulic pump with a large discharge amount to obtain a predetermined lifting speed, and a large amount of energy is lost because the hydraulic jack descends while controlling the speed while restricting the return oil.

The present applicant has proposed Patent Document 1 as an energy saving hydraulic lifting device. According to this document, as shown in FIG. 7, the hydraulic lifting device 120 includes a sheave 125 in which a first pulley 123 and balance weights 124, 124 having substantially the same left and right loads are attached to an upper end block 122 at the upper end of a piston rod 121. Are fixed to the hydraulic cylinder 126. The hydraulic lifting device 120 engages the rope 128 having one end fixed to the structure 127 with the first pulley 123, the second pulley 129 fixed to the structure 127, and the third pulley 130, and is loaded on the other end. A car 131 (hereinafter referred to as a car 131) is attached.
In the hydraulic lifting / lowering device 120, the balance weight 124 cancels out the total weight of the car 131 and the load on which the car is placed when the car is raised, so that the energy saving effect of the electric motor 132 can be obtained.

In the hydraulic cylinder 126 described above, when the reversible rotary hydraulic pump motor 133 supplies hydraulic oil to the cylinder upper chamber 136 from the upper supply / discharge oil port 135 of one cylinder tube 134, the piston 137, that is, the piston rod 121 moves downward. The hydraulic oil in the piston rod 121 is discharged from the lower oil supply / discharge oil port 139 at the lower end of the hollow pipe 138.
When the reversible rotary hydraulic pump motor 133 supplies hydraulic fluid from the other lower supply / discharge oil port 139, the piston rod 121 is pushed upward, and the gap between the inner diameter surface of the cylinder tube 134 and the outer diameter surface of the piston rod 121 is increased. The hydraulic oil is discharged from the upper supply / discharge oil port 135, and the piston rod 121 is reciprocated up and down.

As shown in FIG. 8, in the hydraulic cylinder 126, the inner diameter portion of the ring member 141 is fitted to the lower end portion of the cylinder tube 134, and these are fixed by welding. Then, a bottom cover 142 that is in close contact with the lower end surface of the cylinder tube 134 and fits to the inner diameter surface of the cylinder tube 134 and that has an opening through which the hollow pipe 138 penetrates is fixed by a bolt 143. An O-ring 144 was attached to the fitting portion between the bottom cover 142 and the inner diameter surface of the cylinder tube 134 in order to ensure liquid tightness.
The opening of the bottom cover 142 that penetrates the hollow pipe 138 has a shape that fits into the inner diameter surface of the hollow pipe 138 and is in close contact with the lower surface of the bottom cover 142, and further has a lower oil supply / discharge port 139 at the center. The flanges 145 formed with the bolts 146 were fixed with bolts 146. Note that O-rings 147 and 148 were attached to the fitting portion of the inner surface of the hollow pipe 138 and the close portion of the bottom surface of the bottom cover 142, respectively.

If such a bottom cover 142 is used, the bottom cover 142 and the hollow pipe 138 can be removed by removing the bolt 143, so that the piston 137 can be easily pulled out of the cylinder tube 134. It is proposed that the packings 150 and 151 and the bearing metals 152 and 153 can be easily replaced.
Japanese Patent Publication No. 2003-26378

However, in Patent Document 1, since a balun weight is provided that balances the weight of the cage's own weight W and the weight of about ½ of the maximum load capacity, the hydraulic cylinder 126 shown in FIG. 2, the balance weight becomes heavier when there is no load at the point Xb shown in FIG. 2, and the force in the shrinking direction is exerted on the hydraulic cylinder. Also, when the load is maximum at the point Xc, the cage becomes heavier and extends into the hydraulic cylinder. Directional force is acting.
Also, at point Xa, which is about half the maximum load, the force acting on the hydraulic cylinder is almost zero because the cage and the balance weight are almost balanced, and accordingly the pressure is also almost zero. ing. For this reason, in the vicinity of zero pressure (for example, in the range of XL), there arises a problem that the cage swings instantaneously due to the elevation of the human to the cage and / or the load change of the load.

  For example, in a state where the cage is unloaded and the weight on the balance weight side is heavy, that is, in a state where pressure is generated in a chamber connected to the lower supply / discharge oil port 139 side, the pressure oil of the reversible rotary hydraulic pump motor 133 is applied to the upper part. The cage is raised by supplying the cylinder upper chamber 136 from the oil supply / discharge port 135. At this time, the cage rises while discharging the pressure oil in the chamber connected to the lower supply / discharge oil port 139 side due to the weight on the balance weight side, so that the pressure oil supplied from the reversible rotary hydraulic pump motor 133 to the upper supply / discharge oil port 135 Is discharged at a pressure near the point Xa. In this state, it stops at the upper floor, and when a person with the maximum loading weight gets on the cage, the cage side becomes heavy, pressure due to the weight is generated in the cylinder upper chamber 136, the cage is momentarily lowered slightly, and the cage shakes. .

  Further, the reversible rotating hydraulic pressure is obtained in a state where a person is loaded on the cage to obtain the maximum loading weight and the weight on the cage side is heavy, that is, in a state where pressure is generated in the cylinder upper chamber 136 connected to the upper supply / discharge oil port 135 side. The pressure oil of the pump motor 133 is supplied from the lower supply / discharge oil port 139 to the cylinder to lower the cage. At this time, the cage descends while discharging the pressure oil in the cylinder upper chamber 136 connected to the upper supply / discharge oil port 136 side by its weight, so that the pressure oil supplied from the reversible rotary hydraulic pump motor 133 to the lower supply / discharge oil port 139. Discharges pressure near the point Xa. When the cage is lowered in this state and a person descends on the lower floor, the balance weight side becomes heavier, the cage momentarily rises slightly, and the cage swings. This swaying range occurs, for example, in a predetermined range (pressure Pa) in which the pressure oil contracts, the air in the oil contracts, or the oil seal or the like contracts to expand the volume.

  Further, since the hydraulic elevator is installed in a narrow place as described above, it is strongly desired to improve the maintainability of the hydraulic cylinder for raising and lowering the car. In FIG. 7 of Patent Document 1, the bottom cover 142 and the hollow pipe 138 can be removed by removing the bolt 143, and the piston 137 can be easily pulled out of the cylinder tube 134. It is described that the replacement of the bearing 151 and the bearing metal 152 is facilitated. However, since the bottom end of the bottom cover 142 is attached to the foundation 127a of the structure, it is impossible to remove the bottom cover 142 directly. In order to take out the piston 134, the entire hydraulic cylinder is externally connected by a hoistway. After removal, the hydraulic cylinder must be disassembled and the packing, seal ring and bearing metal must be inspected or replaced. For this reason, after removing a hydraulic cylinder and a balance weight, the operation | work for taking out out of a hoistway is needed, and there exists a problem that maintenance of inspection, replacement | exchange, etc. takes a great man-hour.

  Further, in the hydraulic circuit of the hydraulic elevator disclosed in Patent Document 1 shown in FIG. 7, since a reversible rotation type hydraulic pump motor 133 is used, a specially manufactured hydraulic pump motor 133 is required, and the equipment cost is high. Along with this, there is a problem that a great delivery time is required for production at the time of failure and maintenance is poor.

  The present invention has been made paying attention to the above-mentioned problems, and a first object thereof is to provide a hydraulic circuit of a hydraulic elevator that moves up and down stably without causing vibration when getting on and off the elevator. The second object is to provide a hydraulic circuit for a hydraulic elevator using a hydraulic cylinder with a simple structure and good maintainability.

  In order to achieve the above object, a first invention of a hydraulic circuit for a hydraulic elevator is configured such that the hydraulic pressure of a cylinder for raising and lowering a person and / or a load carrying cage is reduced to about ½ by adding a balance weight. The hydraulic circuit of a hydraulic elevator with reduced power, and at least when loaded onto a cage and / or loaded with a load, its internal pressure is the maximum loading weight or no-load holding pressure, preferably less than the holding pressure. It is characterized by having a double-acting cylinder or a ram type cylinder with a predetermined pressure or more.

  A second invention is a hydraulic circuit of a hydraulic elevator in which the hydraulic pressure of a cylinder for raising and lowering a person and / or a cargo loading cage is reduced to about ½ by attaching a balance weight to reduce the power of a drive source, The balance weight connected to the cage, the protruding part of the ram rod in the elevator machine room, the lowering ram type cylinder in which the cylinder tube is attached to the cage, the protruding part of the ram rod in the cage, and also the cylinder tube It is characterized by comprising a lift ram cylinder attached to the elevator machine room.

  A third invention is a hydraulic circuit of a hydraulic elevator in which the hydraulic pressure of a cylinder for raising and lowering a person and / or a cargo loading cage is reduced to about 1/2 by adding a balance weight to reduce the power of a drive source, The balance weight connected to the cage and the protruding part of the ram rod are in the elevator machine room, the ram cylinder for lowering the cylinder tube is attached to the cage, the protruding part of the ram rod is in the cage, and the cylinder tube is in the elevator machine A cylinder for ascending rams attached to the chamber, and when the cylinder is mounted on the cage and / or loaded with the load, the internal pressure is the maximum loading weight or the holding pressure at the time of no load, preferably the holding pressure or less. It is characterized by being at or above a predetermined pressure.

  According to a fourth aspect of the present invention, there is provided a settling prevention device for setting the hydraulic pressure of the cylinder to a maximum loading weight or a holding pressure at no load, preferably a predetermined pressure equal to or higher than the holding pressure.

  According to the fifth aspect of the present invention, the settling prevention device is configured to apply pressure to the lifting chamber of the double-acting cylinder or the ram type cylinder via the check valve and a pair of check valves connected to the lifting chamber of the double acting cylinder or the ram type cylinder. A hydraulic pump for subsidence supplying oil, an electric motor for preventing subsidence that drives the hydraulic pump for subsidence, a position sensor that detects the stop of the cage, and a lift that is called on a predetermined floor where people and / or luggage are mounted in the cage Signal output means for outputting a signal from any one of a switch for an elevator, an elevator door open switch, a timer, a pressure sensor for detecting the pressure of a cylinder lifting chamber, or a human proximity detection sensor for detecting the approach of a person riding in a cage And a control means for driving the electric motor for preventing settlement by receiving a signal from the signal output means, and a hydraulic pump for preventing settlement that is supplied to the cylinder Holding pressure of maximum loading weight or unloaded pressure oil, preferably is characterized by comprising a relief valve which at least pressure under the holding pressure or.

  In the sixth invention, the settling prevention device includes a control valve that controls the amount of return oil from the double-acting cylinder or the ram type cylinder to the tank, a pressure sensor that detects the pressure of return oil from the cylinder to the tank, and a pressure sensor. Control to output a command to the control valve, throttle the oil returned to the tank, and control the cylinder hydraulic pressure to a maximum loading weight or a holding pressure at no load, preferably a predetermined pressure equal to or lower than the holding pressure. It is characterized by comprising means.

  In the seventh invention, a position sensor that detects a stop position of the cage, a level hydraulic pump that supplies pressure oil that corrects the cage stop position according to a signal from the position sensor to a double-acting cylinder or a ram type cylinder, And a level correcting device including a level electric motor for driving the hydraulic pump and a control unit for receiving the signal from the position sensor and driving the level electric motor.

  In the eighth invention, an emergency hydraulic pump that supplies pressure oil to a double-acting cylinder or a ram type cylinder according to a signal from an emergency switch at the time of an emergency stop of the cage, and an emergency electric motor that drives the emergency hydraulic pump An emergency automatic type comprising a motor, a control means for driving an emergency electric motor in response to a signal from an emergency switch, and a switching valve for supplying pressure oil of an emergency hydraulic pump to one of the lift chambers of the cylinder It has a cage lifting device.

  In the ninth aspect of the invention, the emergency manual hydraulic pump that supplies pressure oil to the double-acting cylinder or the ram type cylinder at the time of an emergency stop of the cage and the pressure oil of the emergency manual hydraulic pump to either of the lift chambers of the cylinder It has an emergency manual type cage lifting and lowering device comprising a manual switching valve for feeding.

According to the first invention, the cylinder is supplied with a holding pressure generated by a maximum load weight or a balance weight, preferably at least a predetermined pressure or more when the car is loaded into the cage and / or when a load is loaded, and pressure is accumulated. Yes. For this reason, when the cage is raised and lowered and / or when the cage is unloaded and loaded, the cage instantaneously sinks and rises and there is no impact and the riding performance is improved.
In addition, by setting the internal pressure of the cylinder to the maximum load weight or the holding pressure at the time of no load, the maximum load weight or the maximum load weight separated from the balance state between the cage and the balance weight of about 1/2 of the maximum load weight Even if the loaded load is changed when there is no load, it will surely be prevented from momentarily sinking and rising slightly, so that it can be lifted and lowered stably and the riding performance is improved. Alternatively, by setting the pressure to a predetermined level or higher, even if the load on the cage changes, the cage does not momentarily sink or rise, and the control pressure is reduced, resulting in greater energy savings. I can plan.

  According to the second invention, since separate ram type cylinders are used for ascending and descending, the ascending / descending speed can be controlled accurately and easily, and the structure is simple because of the ram type cylinder. In addition, because of the ram type cylinder, only the rod head is used as a seal, so that it is easy to attach and detach, and it is easy to inspect and replace, thereby improving maintainability. When used in a hydraulic elevator, the ram type cylinder guides the cage when the cage is raised and lowered, so that a conventional rail for guiding the cage is not required, and the configuration of the elevator can be simplified. Further, since the cage is supported by the ram cylinder fixed to the floor, it is not necessary to strengthen the ceiling, pillars, etc. of the elevator room, and the building can be made inexpensive.

  According to the third invention, the effects of both the first invention and the second invention can be obtained.

  According to the fourth invention, a settling prevention device is provided to ensure that the internal pressure of the double-acting cylinder or the ram type cylinder is at least the maximum loading weight or the holding pressure at the time of no load, at least when boarding the cage and / or loading the load. Since the hydraulic pressure is equal to or higher than the predetermined pressure, momentary slight subsidence and rise that occur at the start of raising and lowering can be reliably prevented.

According to the fifth aspect of the present invention, the pressure oil of the settling prevention hydraulic pump is supplied to the cylinder after being adjusted to a maximum loading weight or a holding pressure at the time of no load, preferably a predetermined pressure or more by the relief valve, and thus the The pressure set by the configuration is obtained. As a result, as described above, it is possible to reliably prevent a slight sinking and rising, and it is possible to cope with vacuum.
In addition, the cylinder can be quickly raised to a predetermined pressure in order to obtain a predetermined hydraulic pressure by operating the electric motor for prevention of settlement and the hydraulic pump for prevention of settlement by detecting the signal output means such as a sensor or a switch. The waiting time can be shortened. Even if a vacuum is generated by a load acting on the cylinder, the cylinder is maintained at a holding pressure, preferably a predetermined pressure or higher, before starting the raising / lowering.

  According to the sixth aspect of the invention, the pressure of the return oil from the cylinder to the tank is detected by the pressure sensor, and the return oil is controlled by the control valve at the maximum load weight or the holding pressure at the time of no load, preferably above the predetermined pressure. Thus, a set pressure can be reliably obtained. As a result, with a simple configuration, it is possible to reliably prevent slight subsidence and elevation that occur instantaneously at the start of elevation.

  According to the seventh invention, since the position of the cage is detected by the position sensor and is corrected by the level correction device when the position is shifted, there is no shift at the time of boarding or loading of the baggage, and the boarding is performed safely and with peace of mind. Can be loaded.

  According to the eighth invention, when the emergency stop of the cage is performed, the emergency switch can be automatically lowered or raised, and can be moved to the safe zone with a simple operation.

According to the ninth aspect of the present invention, an elevator that can move to a predetermined floor and operate safely can be obtained by operating the emergency manual hydraulic pump and the manual switching valve even during a power failure.
In addition, in the above, since the hydraulic circuit of FIG. 1 can use a commercially available hydraulic unit, it is not necessary to manufacture it specially, equipment costs are reduced, and it is possible to easily cope with failure. Maintainability can be improved.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the best embodiment of a hydraulic circuit for a hydraulic elevator according to the present invention will be described with reference to the drawings.
1 is a hydraulic circuit diagram of a hydraulic elevator according to a first embodiment of the present invention.
FIG. 2 is a view for explaining the holding pressure generated in the extension chamber and the reduction chamber when the double-action cylinder according to Embodiment 1 of the present invention is stopped.
FIG. 3 is a diagram for explaining a relationship between pressures generated in the cylinder by the meter-out control according to the first embodiment of the present invention.

In FIG. 1, a hydraulic circuit 1 for a hydraulic elevator according to a first embodiment of the present invention includes a double-acting cylinder 3, an elevating hydraulic device 5 that expands and contracts the double-acting cylinder 3, a cage settlement prevention device 7, and a level correction The device 9 is formed of an emergency automatic cage lifting device 11 and an emergency manual cage lifting device 13. In the hydraulic circuit 1, as will be described in detail later, the speed control of the double-acting cylinder 3 is performed by meter-out control, and the cage CA obtains a predetermined ascending / descending speed.
The double-acting cylinder 3 is connected to an elevator cage CA via a cage wire S and a pulley K. For example, a pulley K is connected to the double-acting cylinder 3, and the cage CA is suspended by a cage wire S wound around the pulley K. The pulley K and the cage are adapted to the expansion and contraction of the double-acting cylinder 3. The cage CA is moved up and down via the wire S. Alternatively, the cage CA may be configured to be mounted on one surface of the piston rod lid 22a of the double acting cylinder 3.

  The pulley K is connected to the balance weight Wb via the balance wire Sr and the fixed pulley Kr. By using the balance weight Wb, the power necessary for raising and lowering the cage CA and the load weight Wt of the person and the luggage is reduced. ing. In the vicinity of the cage CA or the double-acting cylinder 3, a cage position sensor Es for detecting the stop position is provided, and on each floor, an ascending / descending switch Bs for calling the elevator cage CA on that floor is disposed. Yes. Alternatively, an opening switch that opens the door, or a proximity sensor (not shown) that detects that a person has approached may be provided in front of an elevator opening / closing door disposed on each floor.

  The weight Wa of the cage CA is set to an overall weight Wa (Wa = Ws + Wt) based on the own weight Ws of the cage CA and the loaded weight Wt of the person and the load that are loaded in the cage CA. The balance weight Wb includes, for example, a weight Wd obtained by adding the own weight Ws of the cage CA acting on the double acting cylinder 3 and the respective weights of the pulley K, the piston rod 22, the wires S and Sr, and the loading weight Wt. It is set to be approximately equal to the weight obtained by adding about 1/2 of the load weight Wm, and when the load is about 1/2 of the maximum load weight Wm, the balance weight Wb makes the pressure of the double acting cylinder 3 almost zero. It is trying to become.

The double-acting cylinder 3 is pivotally inserted into the cylinder tube 21, the piston tube 22 that is slidably expanded and contracted with respect to the cylinder tube 21, and the piston rod 22 is erected on the cylinder tube 21. And a tube piston 23 that slidably supports the piston rod 22. The tube piston 23 is detachably locked by a pin inserted in a hole formed in the proximal block 21 a of the cylinder tube 21. The double-acting cylinder 3 includes a first space chamber 25 that is a reduction chamber for reducing the cylinder, a second space chamber 26 that is an extension chamber for extending the cylinder, and a third space chamber that becomes a variable volume as the cylinder expands and contracts. 27 is formed.
The first space chamber 25 and the second space chamber 26 are formed with substantially the same cross-sectional area perpendicular to the cylinder axis.

A base end block 21a is attached to the lower portion of the cylinder tube 21, and the base end block 21a is attached to the floor G of the elevator machine room. The double-acting cylinder 3 is installed on the floor G of an elevator machine room (not shown) so that the rod cover 28 and the piston rod lid 22a are on the upper side, and seals attached to the rod cover 28 and the piston rod 22 and The wear ring can be easily replaced and inspected.
The double-acting cylinder 3 has a first space chamber 25 and a second space chamber 26 connected to the lifting hydraulic device 5, and expands and contracts by receiving the pressure oil. In the lifting hydraulic device 5, a lowering hydraulic pump 32 (hereinafter referred to as a lowering pump 32) is provided in the first space chamber 25 through a lowering pipe 31 from the hole 21 b of the cylinder tube 21, and the second space chamber 26. A lift hydraulic pump 35 (hereinafter referred to as a lift pump 35) is connected to the base block 21a through a lift pipe 34.

The lowering pump 32 is connected to the lowering electric motor 36, and the raising pump 35 is connected to the raising electric motor 37, and each is driven by a command from the control unit 47 described later. The third space chamber 27 is connected to a tank 38 and supplies and discharges oil from the tank 38 as the double-acting cylinder 3 expands and contracts. Alternatively, the third space chamber 27 communicates with the atmosphere and supplies and discharges air.
In the first embodiment, the lowering pump 32, the lowering electric motor 36, the ascending pump 35, and the ascending electric motor 37 make it possible to use a commercially available hydraulic unit, so that the equipment cost is reduced. At the same time, it can easily cope with failure and improves maintainability.

A descending check valve 40 and an ascending flow meter 41 are arranged on the descending pipe 31 sequentially from the descending pump 32. Further, a lowering relief valve 43 branches from between the lowering check valve 40 and the ascending flow meter 41 in the first pipe 31a branched from between the lowering pump 32 and the lowering check valve 40. A raised electromagnetic control valve 44 (hereinafter referred to as a raising control valve 44) is disposed in the second pipe 31b.
The descending pipe 31 is provided with an ascending pressure sensor 45 that detects the pressure acting on the first space 25 and transmits the detected pressure to a controller 47 such as a controller. In addition, an oil temperature sensor is attached to the descending pipe 31, and the detected oil temperature is transmitted to the controller 47 such as a controller, and the ascending control valve 44 is controlled so that the ascending speed becomes constant according to the oil temperature. May be. Furthermore, it may be a pressure / oil temperature sensor, and this sensor may be attached to a flow meter, and the detected flow rate, pressure and oil temperature may be transmitted to the controller 47 such as a controller.

The ascending control valve 44 is formed by a servo valve with a check or the like. The ascending control valve 44 is actuated by a command from the control unit 47 when the double-acting cylinder 3 extends to raise the cage CA. The return oil is metered out at positions (a) and (b) as will be described in detail later, and the double acting cylinder 3 is extended at a predetermined speed. The raising control valve 44 allows oil in the tank 38 to pass through the check valve at the position (c) when the double-acting cylinder 3 is reduced and the cage CA is lowered, and is supplied to the first space chamber 25. The vacuum is prevented. Further, a vacuum prevention valve may be disposed in the descending pipe 31 between the ascending flow meter 41 and the first space chamber 25.
The ascending flow meter 41 measures the flow rate of oil returning from the first space chamber 25 to the tank 38, and transmits the flow rate to the control unit 47.

The control unit 47 receives the flow rate signal and pressure signal from the ascending flow meter 41 and the ascending pressure sensor 45, stores the ascending pressure of the cage CA in a storage device such as a ROM, and the ascending rate of the cage CA. Command signal is output to the ascending control valve 44 so that is within a predetermined range.
Further, the control unit 47 receives a signal indicating that the cage CA has been stopped from the cage position sensor Es, and outputs a command to the cage sinking prevention device 7 to operate it, so that at least when the next cage CA is boarded or loaded. The pressure of the double acting cylinder 3 is set to be equal to or higher than a predetermined pressure Pd. Alternatively, the pressure of the double acting cylinder 3 is set to the holding pressure Pm at the time of no load or maximum loading when boarding the next cage CA or loading a load.

A rising check valve 50 and a descending flow meter 51 are disposed in the ascending pipe 34 in order from the ascending pump 35. A lift relief valve 53 is branched from the rise check valve 50 and the descent flow meter 51 to the third pipe 34 a branched from the rise pump 35 and the rise check valve 50. The lowered fourth pipe 34b is provided with a lowering electromagnetic control valve 54 (hereinafter referred to as a lowering control valve 54).
Further, a descending pressure sensor 55 is attached to the ascending pipe 34, detects the pressure acting on the second space 26, and transmits the detected pressure to a controller 47 such as a controller. In addition, it is configured in the same manner as the above-described ascent device when descending, and an oil temperature sensor is also attached to the ascending pipe 34 to control the descending control valve 54 so that the descending speed becomes constant according to the oil temperature. Also good. The descending relief valve 43 and the ascending relief valve 53 are electromagnetic types using a solenoid or the like (not shown) as shown in meter-out control of Example 1 described later, and according to a command from the control unit 47. Thus, the discharge pressures of the descending pump 32 and the ascending pump 35 can be variably controlled.

The lowering control valve 54 is formed by a servo valve with a check or the like, and operates according to a command from the control unit 47 when the double-acting cylinder 3 contracts and lowers the cage CA. The return oil is metered out at positions (d) and (e) to reduce the double acting cylinder 3 at a predetermined speed. The lowering control valve 54 allows the oil in the tank 38 to pass through the check valve at the position (f) when the double-acting cylinder 3 extends and raises the cage CA, and supplies the oil to the second space chamber 26 to make a vacuum. It is prevented from becoming. Further, a vacuum prevention valve may be provided in the ascending pipe 34 between the descending flow meter 51 and the second space chamber 26.
The descending flow meter 51 measures the flow rate of the oil returning from the second space chamber 26 to the tank 38, and transmits the flow rate to the control unit 47.

  The control unit 47 receives the flow rate signal and the pressure signal from the descending flow meter 51 and the descending pressure sensor 55 and stores the descending pressure of the cage CA in a storage device such as a ROM and the descending speed of the cage CA. A command signal is output to the descending control valve 54 so that is within a predetermined range. Further, the control unit 47 receives a signal indicating that the cage CA has been stopped from the cage position sensor Es, and outputs a command to the cage sinking prevention device 7 to operate it, so that at least when the next cage CA is boarded or loaded. The pressure of the double acting cylinder 3 is set to Pd above a predetermined pressure. Alternatively, as in the above-described rise, the holding pressure at no load or the holding pressure at the maximum loading is set.

  The cage settlement prevention device 7 includes a settlement prevention hydraulic pump 7a, a settlement prevention electric motor 7b, a pair of settlement prevention check valves 7c and 7d, a settlement prevention relief valve 7e, and a pair of settlement prevention throttles 7f and 7f. The ascending pressure sensor 45, the descending pressure sensor 55, the tank 38, the cage position sensor Es, the ascending / descending switch Bs, and the control unit 47 are formed. The subsidence prevention hydraulic pump 7a is connected to the descending pipe 31 via the subsidence prevention check valve 7c and the fifth pipe 31c, and the ascending pipe 34 via the subsidence prevention check valve 7d and the sixth pipe 34c. Further, the check valves 40 and 50 and the double-acting cylinder 3 are connected to each other. The settling prevention relief valve 7e is adjusted so that the set pressure is equal to or higher than the predetermined pressure Pd, or the holding pressure Pm at the time of no load or maximum loading. The pair of subsidence prevention throttles 7f buffers the pressure oil of the subsidence prevention hydraulic pump 7a adjusted by the subsidence prevention relief valve 7e and supplies it to the first space chamber 25 and the second space chamber 26 of the double acting cylinder 3. is doing.

The cage settlement prevention device 7 operates as follows. The cage settlement prevention apparatus 7 receives a signal indicating that the cage CA has stopped from the cage position sensor Es, and the control section 47 sends a drive signal to the settlement prevention electric motor 7b in response to the stop signal to prevent the settlement. The electric motor 7b is driven. The settling prevention electric motor 7b rotates the settling prevention hydraulic pump 7a to discharge the pressure oil.
The pressure oil of the settling prevention hydraulic pump 7a is adjusted to a predetermined pressure Pd or a holding pressure Pm at the time of no load or maximum loading by a settling prevention relief valve 7e, and a pair of settling prevention throttles 7f, 7f and It is supplied to the first space chamber 25 and the second space chamber 26 of the double acting cylinder 3 through a pair of settling prevention check valves 7c, 7d. In the double acting cylinder 3, since the cross-sectional areas of the first space chamber 25 and the second space chamber 26 are set to be approximately equal, the internal hydraulic pressure rises without expanding and contracting, and the first space chamber 25 and the second space chamber 26 increases to a predetermined pressure Pd equal to or equal to a holding pressure Pm at the time of no load or maximum loading.
The predetermined pressure Pd is set to be within a range in which the double load cylinder 3 does not sink or rise below the maximum load weight or the holding pressure at no load. The predetermined pressure Pd or the holding pressure Pm at the time of no load or maximum loading can be easily set by adjusting the relief valve 7e for preventing settlement.

In the above, the cage settlement prevention device 7 outputs a command when the control unit 47 receives a signal indicating that the cage CA has stopped from the cage position sensor Es, but during the next boarding and / or loading of the cage CA. When the timer detects that the double acting cylinder 3 has become less than the maximum loading weight or the holding pressure at the time of no load by a timer at a predetermined interval or for the next boarding In response to the door opening signal, the sinking prevention electric motor 7b is started to discharge the pressure oil of the settlement prevention hydraulic pump 7a to the double-acting cylinder 3, or the above may be used in combination as appropriate. .
Thereby, when the double-acting cylinder 3 is at least boarded in the cage CA and / or loaded, the internal pressure thereof is the maximum loading weight or the holding pressure at the time of no load, preferably the maximum loading weight or the holding pressure at the time of no load. It is the predetermined pressure. Further, as shown in an embodiment described later, the above-described settlement prevention relief valve 7e is an electromagnetic type using a solenoid or the like (not shown), and the discharge pressure of the settlement prevention hydraulic pump 7a according to a command from the control unit 47. Can be variably controlled.

  Alternatively, the cage settlement prevention device 7 may be operated as follows. The cage settlement prevention device 7 detects the hydraulic pressure generated in the double-acting cylinder 3 when the cage CA is raised and lowered by the ascending pressure sensor 45 or the descending pressure sensor 55 and sends it to the control unit 47. The control unit 47 stores the stored hydraulic signal in a storage device such as a ROM when the hydraulic pressure signal is lower than the predetermined settling prevention pressure Pd, and sends the stop signal to the cage position when the cage CA stops. In response to the sensor Es, a start signal is output to the electric motor 7b for preventing settlement. The sinking prevention electric motor 7b rotates in response to the start signal to drive the sinking prevention hydraulic pump 7a, generates pressure oil from the sinking prevention hydraulic pump 7a, and passes through the settlement prevention check valves 7c and 7d. The double-acting cylinder 3 is fed.

The double acting cylinder 3 receives the pressure oil of the predetermined pressure Pd adjusted by the settlement prevention relief valve 7e, and instantaneously increases the internal pressure. The pressure oil of the predetermined pressure Pd is depressurized while the ascending control valve 44 or the descending control valve 54 is initially smoothly switched by an instruction from the control unit 47 at the next elevation, and then meter-out control is performed. The pressure is set to a desired required pressure. As a result, the next time the cage CA moves up and down, it starts smoothly without instantaneously sinking or rising.
When the hydraulic pressure when the cage CA is raised and lowered is the predetermined pressure Pd, the control unit 47 does not output a command to the cage settlement prevention device 7, and the double-acting cylinder 3 holds the pressure when raising and lowering. .
In the above description, when the settlement prevention relief valve 7e is not set to the predetermined pressure Pd but is set to the holding pressure Pm at the time of no load or maximum loading, the internal pressure of the double acting cylinder 3 is the holding pressure Pm by the relief valve 7e. The pressure is adjusted.

  The level correction device 9 includes a correction hydraulic pump 9a, a correction electric motor 9b, a correction electromagnetic switching valve 9c, a correction relief valve 9d, a correction throttle valve 9e, a tank 38, a control unit 47, and a cage position sensor. It is formed of Es or the like. The correcting hydraulic pump 9a has a check valve connected to the descending pipe 31 via the seventh pipe 31d connected to the correcting electromagnetic switching valve 9c, and to the ascending pipe 34 via the eighth pipe 34d. 40 and 50 and the double acting cylinder 3 are connected to each other. The correction relief valve 9d is adjusted to a set pressure equal to or higher than the holding pressure Pm at the time of no load or maximum loading.

The level correction apparatus 9 is connected to the cage position sensor Es for detecting the stop position of the cage CA by the control unit 47 and receives a signal that detects that the stop position of the cage CA has shifted by a predetermined interval or more. In addition, a start signal is output to the correcting electric motor 9b. Further, the control unit 47 switches the correction electromagnetic switching valve 9c in accordance with the signal in the direction in which the stop position is deviated, and feeds the pressure oil of the correction hydraulic pump 9a to the double-acting cylinder 3, so that the position of the cage CA is changed. Corrections are made so that the stop position is normal. At this time, the return oil of the double acting cylinder 3 reaches the correction throttle valve 9e via the correction electromagnetic switching valve 9c, and the return oil is throttled by the correction throttle valve 9e, so that the double action cylinder 3 is slowly expanded or contracted. is doing.
For example, when the cage CA descends more than a predetermined interval, the correcting electromagnetic switching valve 9c is switched to the position a, and the pressure oil of the correcting hydraulic pump 9a is passed through the eighth pipe 34d and the rising pipe 34. The double-acting cylinder 3 is extended by being supplied to the second space chamber 26 and corrected so that the position of the cage CA becomes the normal stop position. At this time, since the correction relief valve 9d is adjusted to a set pressure equal to or higher than the holding pressure Pm at the time of no load or maximum loading, the double acting cylinder 3 rises smoothly without sinking.

The details of the emergency automatic cage lifting / lowering device 11 are shown in FIG. 5, but are configured in the same manner as the level correcting device 9 in FIG. 1. In FIG. 5, an emergency automatic cage lifting device 11 includes an emergency hydraulic pump 11a, an emergency electric motor 11b, an emergency electromagnetic switching valve 11c, an emergency relief valve 11d, an emergency throttle valve 11e, a tank 38, an emergency Switch 11f (shown in FIG. 4), control unit 47, and the like.
The emergency switch 11f is disposed in, for example, the cage CA, is connected to the control unit 47 in the same manner as the up / down switch Bs shown in FIG. 1, and is operated by a person boarding the cage CA in an emergency. The emergency hydraulic pump 11a is connected to the descending pipe 31 via the ninth pipe 31e connected to the emergency electromagnetic switching valve 11c, and to the ascending pipe 34 via the tenth pipe 34e. , 51 and check valves 40, 50 are connected to each other. The emergency relief valve 9d is adjusted to a set pressure equal to or higher than the holding pressure Pm at the time of no load or maximum loading.

  In the emergency automatic cage lifting / lowering device 11, when the lifting / lowering hydraulic device 5 breaks down, the emergency electric motor 11b is started in response to the operation signal of the emergency switch 11f by the person who has entered the cage CA. Further, the operation of the emergency switch 11f switches the emergency electromagnetic switching valve 11c, and the emergency electric motor 11b drives the emergency hydraulic pump 11a, and the pressure oil passes through the emergency electromagnetic switching valve 11c. It is fed to the double acting cylinder 3. The double acting cylinder 3 extends or contracts to stop the cage CA at the nearest floor. At this time, the return oil of the double-acting cylinder 3 reaches the emergency throttle valve 11e via the emergency electromagnetic switching valve 11c, and the return oil is throttled by the emergency throttle valve 11e, so that the double-acting cylinder 3 slowly expands or contracts. is doing.

The emergency manual cage lifting / lowering device 13 includes a manual hydraulic pump 13a, a manual switching valve 13b, a manual relief valve 13c, a manual throttle valve 13d, a tank 38, and the like. The manual hydraulic pump 13a is connected to the descending pipe 31 via the eleventh pipe 31f connected to the manual switching valve 13b, and to the ascending pipe 34 via the twelfth pipe 34f. 50 and the double acting cylinder 3 are connected to each other. The manual emergency relief valve 9d is adjusted to a set pressure equal to or higher than the holding pressure Pm at the time of no load or maximum loading.
The emergency manual cage lifting device 13 is operated by a person when the elevator stops due to a power failure or the like. The manual switching valve 13b is switched by a human operation, the manual hydraulic pump 13a is operated by a human, and the pressure oil is fed to the double-acting cylinder 3 through the manual switching valve 13b. The double-acting cylinder 3 extends or contracts according to the operation to stop the cage CA on the next floor. At this time, the return oil of the double-acting cylinder 3 reaches the manual throttle valve 13d through the manual switching valve 13b, and the return oil is throttled by the manual throttle valve 13d, so that the double-acting cylinder 3 slowly expands or contracts. Yes.

Next, the operation of the hydraulic circuit 1 of the hydraulic elevator according to the first embodiment of the present invention will be described.
First, the pressure acting on the double acting cylinder 3 will be described with reference to FIGS. 2 and 3, the horizontal axis indicates the load capacity Wt, the left vertical axis Xb indicates the load capacity Wt is zero (Wo), and the right vertical axis Xc indicates the maximum load capacity Wm. When moving from the left vertical axis to the right vertical axis, the loaded load Wt increases. The vertical axes Xb and Xc indicate the holding pressure Pt generated in the double acting cylinder 3. The balance weight Wb is set to ½ of the maximum load weight Wm, and the holding pressure Pt generated in the double acting cylinder 3 is made zero at the center point Xa.

When the double acting cylinder 3 stops without expansion and contraction, as shown in FIG. 2, the balance weight Wb is between the zero load Wo and 1/2 of the maximum load weight Wm, that is, between the horizontal axis Xb and Xa. Since this is heavier, the piston rod 22 receives a tensile force, and the holding pressure Pt is generated in the first space 25 by the extension force in the double-acting cylinder 3 as shown by a one-dot chain line (A). The holding pressure Pt is the maximum holding pressure Pmo when the loaded weight Wt is zero Wo.
Also, when the loading load Wt is between 1/2 of the maximum loading weight Wm and the maximum loading weight Wm, that is, between the horizontal axes Xa and Xc, the cage CA is heavier, so the piston rod 22 receives a contracting force. As shown by the two-dot chain line (B), the holding pressure Pt is generated in the second space 26 by the reduction force in the double acting cylinder 3. The holding pressure Pt is the maximum holding pressure Pmm when the loading weight Wt is the maximum loading weight Wm. In the above, the holding pressure Pt is zero in the second space 26 and the first space 25 on the opposite sides.

  In FIG. 2, the holding pressure Pmo and the holding pressure Pmm are equal in cross-sectional area between the first space chamber 25 and the second space chamber 26, and the balance weight Wb is set to ½ of the maximum load weight Wm. As a result, the holding pressure Pt is symmetric with respect to the center point Xa, and the maximum holding pressure Pm is obtained when the loading load Wt is zero Wo and the maximum loading weight Wm. The holding pressure Pt is changed by changing the weight of the balance weight Wb with respect to the loaded load Wt or the cross-sectional areas of the first space chamber 25 and the second space chamber 26. The pressure becomes the maximum value, and the relief valve 7e may be set in accordance with either the maximum holding pressure Pmo or Pmm.

Next, a problem that occurs in the conventional hydraulic circuit when the weight of the balance weight Wb is set to ½ of the maximum load weight Wm will be described with reference to FIG.
For example, between Xa and Xb, the balance weight Wb is heavier, so that the first space chamber 25 receives the weight of the balance weight Wb and generates a holding pressure Pt, and the second space chamber 26 is at a low pressure. It has become. When boarding or loading a load on the cage CA in this state, the holding pressure Pt is generated in the second space chamber 26 due to the boarding, but the cage CA momentarily drops because the second space chamber 26 has a low pressure. The boarding ability becomes worse.
Similarly, since the weight of the balance weight Wb is smaller between Xa and Xc, the holding pressure Pt is generated in the second space chamber 26 by receiving the loading weight Wt, and the first space chamber 25 is at a low pressure. ing. If the person boarding in this state or the load is lowered, the balance weight Wb becomes heavy and the holding pressure Pt is generated in the first space chamber 25, but the first space chamber 25 is low in the same manner as described above. The cage CA rises momentarily, resulting in poor rideability. As described above, in the vicinity of zero pressure (for example, in the range of XL), there arises a problem that the cage is instantaneously shaken due to a load change such as a human being moving up and down on the cage.

  In order to prevent this, as shown in FIG. 3, when stopping, the hydraulic pressures of the first space chamber 25 and the second space chamber 26 of the double-acting cylinder 3 are maintained at the maximum holding pressure Pm at the center point Xa, preferably the maximum holding pressure. The pressure Pm is set to be equal to or higher than the predetermined pressure Pd. For this purpose, the control unit 47 operates the subsidence prevention hydraulic pump 7a using the stop signal of the cage CA to stop, preferably at least before boarding the next cage CA and / or before loading. Pressure oil is supplied to the double acting cylinder 3. Accordingly, the hydraulic pressure in the first space chamber 25 and the second space chamber 26 of the double-acting cylinder 3 instantaneously increases at least when the next cage CA is boarded and / or loaded, and the double-acting cylinder 3 is predetermined. The pressure oil of the pressure Pd or the maximum holding pressure Pm is stored. As a result, the cage CA does not sink or rise instantaneously when the loading weight Wt of the cage CA is switched.

As shown in FIG. 2, the predetermined pressure Pd of the pressure oil is almost instantaneously settling or rising due to compression of the pressure oil in the double acting cylinder 3 even when the weight mounted on the cage CA reaches the maximum load Wm. It is set to a pressure that does not occur or to a range of acceptable subsidence and rise. This set pressure is set by a test or the like.
Or, when the weight of the balance weight Wb is heavier than about ½ of the maximum loading weight Wm, the maximum holding pressure Pmo generated at no load becomes larger than the maximum holding pressure Pmm generated at the maximum loading, and vice versa. When the load is light, the maximum holding pressure Pmm generated at the time of maximum loading becomes large, and the relief valve 7e may be set according to either the maximum holding pressure Pmo or Pmm.
Hereinafter, the case where the maximum holding pressure Pmo and the maximum holding pressure Pmm are equal will be described as the maximum holding pressure Pm.

Next, meter-out control for preventing the above-described instantaneous settlement and rise will be described with reference to FIG. In the meter-out control of the first embodiment, when the holding pressure in FIG. 2 is high, the pressure of the descending pump 32 is regulated by the descending relief valve 43, and the pressure of the raising pump 35 is regulated by the raising relief valve 53, The discharge pressure is adjusted according to the holding pressure Pt, and pressure oil is supplied to the double acting cylinder 3.
For example, when the loaded load is zero (Wo) and the holding pressure of the maximum loaded load WL is high, pressure oil with a low discharge pressure from the pumps 32 and 35 is used, and the loaded load is WL / 2 (the Xa point of the center point). When the holding pressure is low, high pressure oil is supplied from the pumps 32 and 35. Thus, the pressure of return oil can be made substantially constant by appropriately selecting the discharge pressure of the pumps 32 and 35. As a result, the pressure of the return oil from the double acting cylinder 3 to the tank 38 can be made a small pressure difference, and the area difference of the throttle in the ascending control valve 44 or the descending control valve 54 can be reduced, thereby improving the flow rate accuracy. Can be improved.

In the meter-out control, as shown in an example in FIG. 3, when the double-acting cylinder 3 is expanded and contracted, the pressure in the first space chamber 25 gradually increases from the horizontal axis Xb to Xc as shown by the dotted line (D). On the contrary, the pressure in the second space chamber 26 gradually increases from the horizontal axis Xb toward Xc as shown by the solid line (E). In this embodiment, the meter-out control is performed by changing the increase / decrease amount (inclination angle) at the center point Xa, but it may be a straight line or a curve.
Hereinafter, an example in which the set pressure of the relief valve 7e is set to the predetermined pressure Pd will be described. However, as described above, it may be set to the maximum holding pressure Pm generated at the time of no load or maximum loading. In this case, the same control may be performed.

In FIG. 3, first, the case where the cage CA is raised will be described.
When the loaded weight Wt is between the horizontal axes Xb and Xa (for example, the point Xe), the weight of the balance weight Wb is heavier than the weight of the cage CA, and the first space chamber 25 is stopped by the balance weight Wb when stopped. The holding pressure Pte is generated in In this state, in order to raise the cage CA, the raising pump 35 is started and pressure oil at the discharge pressure Pe is supplied to the second space chamber 26. This pressure Pe raises the holding pressure Pte of the first space chamber 25 to the pressure oil of the return pressure Pre via the piston rod 22. The pressure oil of the return pressure Pre of the first space chamber 25 generated by the balance weight Wb and the discharge pressure Pe is determined by the position (a) of the ascending control valve 44 that operates in response to a command from the control unit 47 on the way to the tank 38. The meter-out control is performed so that the pressure is reduced to a predetermined pressure, that is, a constant flow rate. The ascending control valve 44 controls the amount of oil returned to the tank 38 to keep the ascending speed of the cage CA constant. The discharge pressure Pe of the raising pump 35 at this time is regulated by the raising relief valve 53 set according to the holding pressure Pte based on the loaded weight Wt and the set return pressure Pre.

  When the loaded weight Wt is between the horizontal axes Xa and Xc (for example, the point Xf), the weight on the cage CA side is heavier than the weight of the balance weight Wb. A holding pressure Ptf is generated in the two space chamber 26. In this state, in order to raise the cage CA, the raising pump 35 is started and pressure oil having a discharge pressure Pf equal to or higher than the holding pressure Ptf is supplied from the raising pump 35 to the second space chamber 26. The discharge pressure Pf acts on the return oil in the first space chamber 25 via the piston rod 22, and the return oil is changed from substantially zero (Pfo) to the return pressure Pfr. The pressure oil of the return pressure Pfr of the first space chamber 25 caused by the difference between the holding pressure Ptf and the discharge pressure Pf due to the loaded weight Wt is throttled by the raising control valve 44 on the way back to the tank 38 to a predetermined return pressure. The meter-out control is performed as follows.

The ascending control valve 44 controls the amount of oil returned to the tank 38 to keep the ascending speed of the cage CA constant. At this time, the ascending pump 35 keeps the ascending speed of the cage CA constant according to the amount of oil discharged into the second space chamber 26, and the discharge pressure Pf depends on the loaded weight Wt and the set return pressure Pfr. The pressure is adjusted by the set up relief valve 53.
In the above, the average pressure in the first space chamber 25 and the second space chamber 26 of the double-acting cylinder 3 is equal to or lower than the predetermined pressure Pd. For this reason, when the cage Ca rises and stops at a predetermined floor, the stop is detected by the position sensor ES and transmitted to the control unit 47, and the control unit 47 operates the cage settlement prevention device 7 to activate the double-action cylinder 3. The pressure in the first space chamber 25 and the second space chamber 26 is set to a predetermined pressure Pd.

Next, a case where the cage CA is lowered will be described.
When the loaded weight Wt is between the horizontal axes Xb and Xa (for example, the point Xe), the holding pressure Pte is generated in the first space chamber 25 by the balance weight Wb as in the above-described rise, and the cage CA is lowered in this state. Therefore, the lowering pump 32 is started, and the pressure oil of the discharge pressure Pre of the lowering pump 32 is supplied to the first space chamber 25 where the holding pressure Pte is generated. Meter-out control for reducing the pressure oil of the return pressure pe generated from zero in the second space chamber 26 by the discharge pressure Pre at the position (d) of the lowering control valve 54 to a predetermined pressure and making the return flow rate constant. To do. Thus, the cage CA can obtain a constant lowering speed by controlling the amount of oil discharged from the lowering pump 32 and the oil amount of the lowering control valve 54.

  Further, when the loaded weight Wt is between the horizontal axes Xa and Xc (for example, the point Xf), the holding pressure Ptf is generated in the second space chamber 26 due to the weight on the cage CA side as described above, and in this state In order to lower the cage, the lowering pump 32 is started, and the pressure oil having the discharge pressure Pfr is supplied from the lowering pump 32 to the first space chamber 25. This discharge pressure Pfr pressurizes the holding pressure Ptf of the second space chamber 26 via the piston rod 22 to make the return pressure Pf. The return oil in the second space chamber 26 is throttled by the position (d) of the lowering control valve 54 on the way back to the tank 38 and is metered out so as to have a predetermined return pressure. The lowering pump 32 keeps the lowering speed of the cage CA constant by controlling the amount of oil discharged to the first space chamber 25 and the amount of return oil from the second space chamber 26, and the discharge pressure Pfr is the load weight. The pressure is regulated by the lowering relief valve 43 set according to the holding pressure Ptf by Wt and the set return pressure Pf.

At this time, the pressure in the first space chamber 25 and the second space chamber 26 of the double acting cylinder 3 is equal to or lower than the predetermined pressure Pd. For this reason, when the cage Ca descends and stops at a predetermined floor, the stop is detected by the position sensor ES and transmitted to the control unit 47, and the control unit 47 operates the cage settlement prevention device 7 in the same manner as when the cage Ca rises. Thus, the average pressure in the first space chamber 25 and the second space chamber 26 of the double acting cylinder 3 is set to a predetermined pressure Pd.
As a result, when boarding the next cage CA and / or loading the load, the internal pressure of the double-acting cylinder 3 becomes a predetermined pressure Pd that is equal to or lower than the maximum holding pressure Pm and sinks even if the load on the cage CA fluctuates. Or generation | occurrence | production of a raise etc. can be prevented.

Next, the operation of the hydraulic elevator using the hydraulic circuit 1 of the first embodiment will be described.
For example, a person who wants to go on a hydraulic elevator and go to the upper floor pushes the lift switch Bs on the outside of the cage CA on the boarding floor. The rising signal is sent to the control unit 47. When the control unit 47 is on the floor on which the cage CA is boarded, the control unit 47 operates the cage settlement prevention device 7 before outputting a command to open the door, thereby causing a relief for settlement. The pressure oil of the settling prevention hydraulic pump 7a adjusted to the predetermined pressure Pd by the valve 7e is supplied to the first space chamber 25 and the second space chamber 26 of the double acting cylinder 3. The double-acting cylinder 3 rises to an equal predetermined pressure Pd where the first space chamber 25 and the second space chamber 26 do not sink and rise instantaneously. Thereafter, the control unit 47 outputs a command to open the door and opens the door. As a result, even if the maximum number of people get on the cage CA, it does not sink instantaneously. At this time, the controller 47 may improve safety when the door is opened after the pressure sensors 45 and 55 detect that the double-acting cylinder 3 has risen to the predetermined pressure Pd.

When the cage CA is not on the floor on which the boarding is carried, the control unit 47 operates the lifting / lowering hydraulic device 5 in order to move the cage CA to the boarding board. For example, when moving the cage CA to a floor above the lower floor, the control unit 47 outputs a command to the ascending electric motor 37 and drives the ascending pump 35 to generate pressure oil. This pressure oil is sent from the proximal block 21a to the second space chamber 26 via the ascent check valve 50 and the ascending flow meter 51, and the piston rod 22 of the double acting cylinder 3 extends.
As the piston rod 22 extends, the first space chamber 25 is reduced and the internal oil is discharged from the descending pipe 31. At this time, the ascending signal is also sent to the control unit 47, and the control unit 47 operates the ascending control valve 44.

  The return oil from the first space chamber 25 reaches the ascending control valve 44 via the ascending flow meter 41 and the branched second piping 31b from the descending pipe 31, and the flow rate is measured by the ascending control valve 44. It is controlled to return to the tank 38. The flow rate of the return oil is measured by the ascending flow meter 41 and the pressure is measured by the ascending pressure sensor 45 and transmitted to the control unit 47. The control unit 47 outputs a command value corresponding to the pressure to the ascending control valve 44 to throttle the return oil, and performs meter-out control of the flow rate by the ascending control valve 44 so that the ascending speed of the hydraulic elevator falls within a predetermined range. ing. The second space chamber 26 receives the flow rate of the ascending pump 35, and the double acting cylinder 3 expands. After the cage CA is moved to the floor on which the cage CA is mounted, the expansion is stopped, and the cage CA is stopped on the predetermined floor.

  At this time, the control unit 47 receives the stop of the cage CA from the cage position sensor Es and operates the cage settlement prevention device 7. The cage settlement prevention device 7 starts the settlement prevention electric motor 7b, and supplies pressure oil to the double acting cylinder 3 from the prevention hydraulic pump 7a. In the double-acting cylinder 3, the hydraulic pressure in the first space chamber 25 and the second space chamber 26 is increased, and the double-action cylinder 3 is adjusted to a predetermined pressure Pd or more by the settlement prevention relief valve 7e. As a result, the next hydraulic pressure in the first space chamber 25 and the second space chamber 26 is the predetermined pressure Pd when boarding the cage CA and / or when loading a load, and therefore smooth without instantaneously sinking or rising. To start.

When it is desired to lower the vehicle by a hydraulic elevator, the lowering switch Bs on the boarding floor is similarly pushed outside the cage CA. When the cage CA is on the boarding level, the cage sinking prevention device 7 is operated before the door is opened, and the first space chamber 25 and the second space chamber 26 of the double-acting cylinder 3 are operated. The pressure is increased to a predetermined pressure Pd.
When the cage CA is not on the floor on which the boarding is carried, the control unit 47 operates the lifting / lowering hydraulic device 5 in order to move the cage CA to the boarding board. For example, when moving the cage CA to a floor below the upper floor, the control unit 47 outputs a command to the lowering electric motor 36 to drive the lowering pump 32 to generate pressure oil. This pressure oil is sent to the first space chamber 25 through the check valve 40 for lowering and the flow meter 41 for rising, and the piston rod 22 of the double acting cylinder 3 is contracted.
As the piston rod 22 is reduced, the second space chamber 26 is reduced and the internal oil is discharged from the ascending pipe 34. The lowering signal of the lowering switch Bs is also sent from the control unit 47 to the lowering control valve 54, and the lowering control valve 54 is operated.

  The return oil from the second space chamber 26 reaches the descending control valve 54 through the descending flow meter 51 from the ascending pipe 34, the flow rate is metered out by the descending control valve 54, and returns to the tank 38. The flow rate of the return oil is measured by the descent flow meter 51 and the pressure is measured by the descent pressure sensor 55 and transmitted to the control unit 47. The control unit 47 outputs a command value corresponding to the pressure to the descending control valve 54 to throttle the return oil, and performs meter-out control of the flow rate by the descending control valve 54 so that the descending speed of the hydraulic elevator falls within a predetermined range. ing. The double space cylinder 25 receives the flow rate of the lowering pump 32, and the double acting cylinder 3 is reduced. After the cage CA is moved to the floor on which the cage CA is mounted, the reduction is stopped, and the cage CA is stopped on the predetermined floor.

  At this time, the control unit 47 receives the fact that the cage CA has stopped from the cage position sensor Es and operates the cage settlement prevention device 7. The cage settlement prevention device 7 operates in the same manner as when it is raised, and raises the hydraulic pressure in the first space chamber 25 and the second space chamber 26 of the double-acting cylinder 3 to a predetermined pressure Pd. As a result, the next time the cage CA moves up and down, it starts smoothly without instantaneously sinking or rising. As described above, at least during the next raising / lowering, the double-acting cylinder 3 may be raised to a predetermined pressure Pd or higher.

In the hydraulic elevator described above, the double-acting cylinder 3 has its own weight Wt and the load Wt of the cage CA reduced by the balance weight Wb and acts as a weight of only the load Wt. Can be expanded and contracted with a small pressure. In addition, the double acting cylinder 3 supplies and discharges small volumes of pressure oil in the first space chamber 25 and the second space chamber 26, so that the lowering pump 32 and the raising pump 35 require a smaller discharge amount. Even in the out control, the supply pressure of the pump is made as low as possible to control the return oil with a reduced throttle pressure, so that it is driven with a small driving force, so that energy saving can be achieved.
For example, when the loaded load is 750 kg and the speed is 45 m / min, the cage CA can be raised and lowered with about 1/3 of the electric power compared to the conventional case.

In the above, the control unit 47 detects the stop of the cage CA by the cage position sensor Es and operates the cage settlement prevention device 7 by the stop signal, and at least at the next raising and lowering, the double acting cylinder 3 is set to a predetermined pressure Pd or higher. However, it may be as follows.
(1) Using a controller or the like for the control unit 47, the set predetermined pressure Pd (or the maximum holding pressure Pm) is compared with the return pressure at the time of raising and lowering measured by the pressure sensors 45 and 55, and measured. When the return pressure is lower than the set predetermined pressure Pd (or maximum holding pressure Pm), the cage settlement prevention device 7 is started, and the pressure of the double acting cylinder 3 is set to the predetermined pressure Pd (or maximum holding pressure Pm). May be.
At this time, the control unit 47 calculates an average value of the pressures in the first space chamber 25 and the second space chamber 26 of the double acting cylinder 3, and the value is a predetermined pressure Pd (or the maximum holding pressure Pm) when the cage is stopped. It is good to be in.
(2) Although a controller or the like is used for the control unit 47 in the above, a cage switch is prevented by providing a relay switch or the like that receives a signal from the push button of the cage CA stop and ascending / descending switch Bs. 7 may be activated, and the pressure of the double acting cylinder 3 may be set to the predetermined pressure Pd or the maximum holding pressure Pm.
(3) When the cage CA is on the floor where the push button is pressed, the cage settlement prevention device 7 is operated before opening the door, but the pressure of the double-acting cylinder 3 is detected by the pressure sensors 45 and 55, and the pressure is predetermined. When it is at the pressure Pd or the maximum holding pressure Pm, the elevator door may be opened immediately without operating the cage settlement prevention device 7.
(4) While waiting for the elevator, the pressure of the double acting cylinder 3 is detected by the pressure sensors 45 and 55, and when the pressure falls below the predetermined pressure Pd or the maximum holding pressure Pm, the cage settlement prevention device 7 is activated. Then, the pressure of the double acting cylinder 3 may be constantly maintained at the predetermined pressure Pd or the maximum holding pressure Pm.
(5) During the standby of the elevator, the cage settlement prevention device 7 may be activated by a timer or the like every predetermined time, and the pressure of the double acting cylinder 3 may be set to the predetermined pressure Pd or the maximum holding pressure Pm.
(6) A proximity sensor may detect that a person has approached the elevator door, and the cage settlement prevention device 7 may be activated. As a result, it is possible to shorten the time until the double-acting cylinder 3 is quickly set to the predetermined pressure Pd or the maximum holding pressure Pm and the door is opened.
(7) The cage settlement prevention device 7 may be operated by combining the above.

Next, a hydraulic circuit 1A for a hydraulic elevator according to a second embodiment of the present invention will be described with reference to FIGS.
Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
FIG. 4 is a configuration diagram of an elevator cage, a ram cylinder, and a balance weight according to a second embodiment of the present invention.
FIG. 5 is a hydraulic circuit diagram of the hydraulic elevator according to the second embodiment of the present invention.
FIG. 6 is a diagram for explaining the relationship of pressure generated in the cylinder by meter-out according to the second embodiment of the present invention.
When the double acting cylinder 3 is set to the predetermined pressure Pd or the maximum holding pressure Pm, the stop of the cage CA is detected and the cage settlement prevention device 7 is operated in the first embodiment. This is done by meter-out control when moving up and down.
In the following, the average value of the return pressure and the pump pressure is set to be equal to or higher than the maximum holding pressure Pm, and the term will be described using the maximum holding pressure Pm or higher.

4 and 5, the hydraulic circuit 1A of the hydraulic elevator according to the second embodiment of the present invention includes a descending ram cylinder 61, an ascending ram cylinder 62, and an elevator for extending and contracting both cylinders 61 and 62. The hydraulic device 5A, the cage settlement prevention device 7, the level correction device 9, the emergency automatic cage lifting device 11, the emergency manual cage lifting device 13, and the controller 47A such as a controller are formed. .
As will be described in detail later, the hydraulic circuit 1A is controlled by the ascending control valve 44 or the descending control valve 54 in which the speeds of the descending ram cylinder 61 and the ascending ram cylinder 62 are instructed by the controller 47A. The cage CA obtains a predetermined ascending / descending speed and a maximum holding pressure Pm when the cylinders 61 and 62 are stopped.

The cage CA is provided on each balance weight Wb by a balance wire Sr wound around a pair of fixed pulleys Kr, and on each of a pair of descending ram type cylinders 61 and one ascending ram type cylinder 62, respectively. It is connected. The cage CA moves up and down as the cylinders 61 and 62 expand and contract with the pressure oil in which the pressure for operating the cylinders 61 and 62 is reduced by the balance weight Wb.
In the lowering ram type cylinder 61, the protruding portion of the ram rod 61a is attached to the ceiling or the like of the machine room of the elevator, and the ram tube 61b that houses the ram rod 61a and is slidable on the ram rod 61a is a cage CA. Has been attached to. The lowering ram type cylinder 61 has a hole 61c formed in the ram rod 61a connected to the lowering piping 31 of the lifting hydraulic device 5A, and extends by receiving pressurized oil to lower the cage CA. The ram rod 61a uses a steel pipe for cylinder, closes its upper end and lower end, and has a passage formed by a pipe or the like in its interior, so that the weight can be reduced and the amount of oil inside can be reduced. The lowering ram type cylinder 61 has only the ram rod 61a attached to the elevator machine room ceiling, etc., and does not support the cage CA, so it is necessary to strengthen the machine room ceiling, building beams, columns, etc. The building can be made inexpensive.

The ascending ram type cylinder 62 includes an ascending ram tube 62b in which the protruding portion of the ascending ram rod 62a is located at the bottom of the cage CA, and the ascending ram rod 62a is accommodated and slidable on the ascending ram rod 62a. It is attached to the floor G of the elevator machine room. The ascending ram type cylinder 62 is accommodated in a bit Gb or the like in which the ascending ram tube 62b is dug. The ascending ram type cylinder 62 has a hole 62c formed in the ascending ram tube 62b connected to the ascending piping 34 of the ascending / descending hydraulic apparatus 5A, and extends by receiving pressurized oil to raise the cage CA.
As described above, the lowering ram type cylinder 61 and the rising ram type cylinder 62 do not have a piston and use a ram having a simple structure. Therefore, inspection and replacement of seals are easy. Further, the raising ram type cylinder 62 supports the cage CA and the raising ram type cylinder 62 is attached to the floor of the machine room. Therefore, it is only necessary to strengthen the floor, and the building can be made inexpensive.

In FIG. 5, the lifting hydraulic device 5A has a descending pipe 31 connected to a descending pump 32A and an ascending pipe 34 connected to an ascending pump 35A. Both pumps 32A and 35A are bi-directionally rotating. It is connected to and driven by an electric motor 37A (hereinafter referred to as a bidirectional electric motor 37A). The discharge pressures of both the pumps 32A and 35A are regulated by a descending relief valve 43 and an ascending relief valve 53. For example, as shown in FIG. 6, the set pressure PUr of the ascending relief valve 53 and the set pressure PDr of the descending relief valve 43 are higher than the maximum holding pressure Pm in consideration of the minimum operating pressure and its margin value. Is set. The set pressure PUr of the ascending relief valve 53 and the set pressure PDr of the descending relief valve 43 may be set to the same set pressure according to the maximum holding pressure Pm, or may be set to different values.
For example, the descending pump 32A rotates clockwise and the ascending pump 35A rotates counterclockwise to generate pressure oil, and the pumps 32A and 35A rotate counterclockwise (referred to as reverse rotation) to reduce the oil in the tank 38 as described later. It is circulated in.

The first pipe 31a branched from between the lowering pump 32A and the lowering check valve 40 is provided with an ascending suction valve 64, and the ascending suction valve 64 is reversed by the descending pump 32A. When the oil is in the tank, the oil in the tank 38 is allowed to pass through, sucked by the lowering pump 32A, and discharged as it is to the tank 38 at a low pressure.
A lower suction valve 65 is disposed in the third pipe 34a branched from between the lift pump 35A and the lift check valve 50, and the lift pump 35A reverses the lower suction valve 65. When the oil is in the tank, the oil in the tank 38 is allowed to pass through, is sucked into the ascending pump 35A, and is directly discharged to the tank 38 at a low pressure.

The bi-directional electric motor 37A receives the signal from the up / down switch Bs and determines the direction of rotation. For example, the bi-directional electric motor 37A is rotated clockwise to send pressure oil from the lowering pump 32A to the lowering ram type cylinder 61 and extend. At the same time, the ascending pump 35A is reversed and the oil in the tank 38 is sucked from the descending suction valve 65 as indicated by the dotted line Y and circulated at a low pressure.
On the other hand, the counterclockwise pump sends pressure oil from the ascending pump 35A to the ascending ram type cylinder 62 and extends it, and reverses the descending pump 32A so that the oil in the tank 38 is fed from the ascending suction valve 64 as indicated by the dotted line V. Aspirated and circulated at low pressure. At this time, the lowering pump 32A and the raising pump 35A are constant displacement hydraulic pumps. Thereby, similarly to Example 1, an inexpensive hydraulic pump can be used.

The control unit 47A receives the flow signal and the pressure signal from the ascending flow meter 41 and the ascending pressure sensor 45 when the cage CA is raised, and the return pressure when the cage CA is raised exceeds the maximum holding pressure Pm. A command signal is output to the ascending control valve 44 so that the ascending speed of the cage CA falls within a predetermined range. The raising control valve 44 squeezes the return oil from the lowering ram type cylinder 61 to the tank 38 so as to be equal to or higher than the maximum holding pressure Pm, and controls the raising speed of the cage CA to be within a predetermined range.
The discharge pressure of the ascending pump 35A is within the range of the constant pressure PUr of the ascending relief valve 53 shown by the solid line in FIG. 6A, and the descending ram type cylinder 61 that keeps the ascending speed of the cage CA constant. It is automatically set from the relationship between the return pressure and the holding pressure generated in the ascending ram cylinder 62 according to the load weight Wt of the cage CA.

Further, the control unit 47A receives the flow rate signal and the pressure signal from the descending flow meter 51 and the descending pressure sensor 55 when the cage CA descends, and the return pressure when the cage CA descends exceeds the maximum holding pressure Pm. And a command signal is output to the lowering control valve 54 so that the lowering speed of the cage CA falls within a predetermined range. The descending control valve 54 squeezes the return oil from the ascending ram cylinder 62 to the tank 38 so as to be equal to or higher than the maximum holding pressure Pm, and controls the ascending speed of the cage CA to be within a predetermined range. The discharge pressure of the descending pump 32A is set so as to fall within the range of the constant pressure PDr of the ascending relief valve 53 indicated by a dotted line in FIG.
In FIG. 6A, the return pressure from the descending ram type cylinder 61 is displayed at a value smaller than the maximum holding pressure Pm in the vicinity of the maximum loading load Wm. The discharge pressure becomes larger than the maximum load load Wm, and the average value of the pressure of the descending ram cylinder 61 and the lift ram cylinder 62 is equal to or greater than the maximum load load Wm. The same applies to FIG. 6B.

  Next, the operation of the hydraulic circuit 1A will be described with reference to FIG. For example, as in the first embodiment, when the loaded weight Wt is between the horizontal axes Xb and Xa, for example, Xh, the weight of the balance weight Wb is heavier than the weight on the cage CA side. A holding pressure Pth is generated in the descending ram cylinder 61 by Wb. In this state, in order to raise the cage CA, the raising pump 35A is started and the discharge pressure Ph is supplied to the raising ram type cylinder 62. The pressure Ph acts on the descending ram cylinder 61 via the ascending ram rod 62a and the cage CA, and raises the holding pressure Pth to the return pressure Prh. The return pressure Prh of the descending ram cylinder 61 is throttled by the ascending control valve 44 while returning from the descending ram cylinder 61 to the tank 38 so that a predetermined return pressure, that is, a return flow rate becomes constant. Meter-out control. The ascending control valve 44 restricts the amount of oil returned to the tank 38 and keeps the ascending speed of the cage CA constant. The discharge pressure Ph of the ascending pump 35A changes according to the loaded weight Wt and the set return pressure Prh.

Next, when the loaded weight Wt is between the horizontal axes Xa and Xc, for example Xi, the weight on the cage CA side is heavier than the weight of the balance weight Wb, and when stopped, the weight is increased by the weight on the cage CA side. A holding pressure Pti is generated in the ram type cylinder 62 for use. In this state, in order to raise the cage CA, the raising pump 35A is started and a discharge pressure Pi equal to or higher than the holding pressure Pti is supplied from the raising pump 35A to the raising ram cylinder 62. This pressure Pi acts on the descending ram type cylinder 61 through the cage CA in the same manner as described above, and the return oil is changed from substantially zero (Pro) to the return pressure Pri. The pressure oil of the return pressure Pri of the descending ram cylinder 61 is metered out so that it is throttled by the ascending control valve 44 and reaches a predetermined pressure on the way back to the tank 38. At this time, the ascending pump 35A keeps the ascending speed of the cage CA constant according to the amount of oil discharged to the ascending ram type cylinder 62, and the discharge pressure Pf is a return that is set to the weight Wt mounted on the cage CA. It changes according to the pressure Prf.
In the above, when the cage Ca rises and stops at a predetermined floor, the descending ram cylinder 61 and the ascending ram cylinder 62 are averaged via the cage CA, and the internal pressure becomes equal to or higher than the maximum holding pressure Pm. Yes.

  Next, the case where the cage CA is lowered will be described with reference to FIG. When the loaded weight Wt is between the horizontal axes Xb and Xa, the holding pressure Pth is generated in the lowering ram type cylinder 61 by the balance weight Wb as in the case of the rising, and the lowering pump 32A is used to lower the cage in this state. Is started, and the discharge pressure of the lowering pump 32A is supplied to the lowering ram type cylinder 61. This discharge pressure acts on the ascending ram cylinder 62 via the cage CA in the same manner as described above. The return pressure of the return oil in the ascending ram cylinder 62 increases from zero to Prh, and the return pressure Prh is metered out by the control valve 54 for lowering so that a predetermined return pressure, that is, a constant return oil amount is obtained. As a result, a constant lowering speed of the cage CA is obtained.

  Further, when the loaded weight Wt is between the horizontal axes Xa and Xc, the holding pressure Pti is generated in the lifting ram cylinder 62 due to the weight on the cage CA side as described above, and the cage is lowered in this state. Then, the lowering pump 32A is started and fed to the lowering ram cylinder 61 from the lowering pump 32A. This discharge pressure raises the pressure oil of the raising ram cylinder 62 from the holding pressure Pti to the return pressure Pri via the cage CA. The return oil from the ascending ram type cylinder 62 to the tank 38 is throttled by the descending control valve 54 and is metered out to a predetermined return pressure. At this time, the descending speed of the cage CA is kept constant by the amount of oil discharged by the descending pump 32A.

In the above, when the cage Ca descends and stops at a predetermined floor, the descending ram type cylinder 61 and the ascending ram type cylinder 62 are averaged through the cage CA, and the internal pressure becomes equal to or higher than the maximum holding pressure Pm. Yes.
As a result, when boarding the next cage CA and / or loading a load, the internal pressure of the descending ram type cylinder 61 and the ascending ram type cylinder 62 becomes the maximum loading weight or the holding pressure when there is no load. Even if the load on the CA fluctuates, the occurrence of subsidence or rise can be prevented.

Next, the operation of the hydraulic elevator using the hydraulic circuit 1A will be described. For example, when the hydraulic elevator is raised, the raising switch Bs is pushed. The two-way electric motor 37A receives this ascent signal from the control unit 47A and rotates to generate pressure oil in the ascending pump 35A. This pressure oil is sent to the ascending ram type cylinder 62 through the ascending check valve 50 and the ascending flow meter 51, and extends the ascending ram type cylinder 62, and the descending ram type cylinder via the cage CA. 61 is reduced to raise the cage CA.
As the descending ram cylinder 61 is reduced, the oil inside the descending ram cylinder 61 is discharged from the descending pipe 31 to the tank 38 through the second pipe 31 b and the ascending control valve 44. At this time, the ascending signal is also transmitted from the controller 47A to the ascending control valve 44, and the ascending control valve 44 is operated.

The return oil from the descending ram type cylinder 61 is returned to the tank 38 after the pressure is controlled to the maximum holding pressure Pm by the ascending control valve 44 and the flow rate is metered out in accordance with the ascending speed. The return oil is transmitted to the control unit 47A after the flow rate is measured by the ascending flow meter 41 and the pressure is measured by the ascending pressure sensor 45. The controller 47A controls the ascent control valve 44 while confirming the pressure by the ascending pressure sensor 45 and the flow rate by the ascending flowmeter 41, and controls the rise of the cage CA of the hydraulic elevator meter-out. .
Thereby, the descending ram type cylinder 61 is adjusted to a return pressure that is equal to or higher than the maximum holding pressure Pm and according to the loaded weight Wt. The ascending ram cylinder 62 receives the pressure of the ascending pump 35A set by the return pressure of the descending ram cylinder 61 corresponding to the loading weight Wt and the pressure generated by the loading weight Wt of the cage CA. The internal pressure is not less than the maximum holding pressure Pm. As a result, when the cage CA next rises, both cylinders 61 and 62 are at least at the maximum holding pressure Pm, and both cylinders 61 and 62 start smoothly without instantaneously sinking or rising.

When the hydraulic elevator is lowered, the lowering switch Bs is pushed. The two-way electric motor 37A receives the lowering signal from the control unit 47A and rotates to generate pressure oil in the lowering pump 32A. This pressure oil is sent to the descending ram type cylinder 61 via the descending check valve 40 and the descending flow meter 41 to extend the descending ram type cylinder 61 and also through the cage CA. 62 is reduced to lower the cage CA.
As the ascending ram cylinder 62 is reduced, the oil inside the ascending ram cylinder 62 is discharged from the ascending pipe 34 to the tank 38 via the fourth pipe 34 b and the descending control valve 54. At this time, the lowering signal is also transmitted from the control unit 47A to the lowering control valve 54, and the lowering control valve 54 is operated.

The return oil from the ascending ram type cylinder 62 is returned to the tank 38 under the control of the descending control valve 54 where the pressure is controlled to the maximum holding pressure Pm and the flow rate is metered out in accordance with the descending speed. The return oil is transmitted to the controller 47A after the flow rate is measured by the descending flow meter 51 and the pressure is measured by the descending pressure sensor 55. The controller 47A controls the descent control valve 54 while confirming the pressure by the descent pressure sensor 55 and the flow rate by the descent flow meter 51, and controls the descent of the cage CA of the hydraulic elevator meter-out. .
As a result, when the cage CA is moved up and down next time, both cylinders 61 and 62 are at least the maximum holding pressure Pm or more, and both cylinders 61 and 62 do not sink or rise instantaneously. Start smoothly.

Next, in the third embodiment using the hydraulic circuit 1 or the hydraulic circuit 1A, an example in which the pressure is increased to a predetermined pressure Pd or higher or the maximum holding pressure Pm when the cage is raised and lowered will be described.
In the third embodiment, when the return pressure from the cylinder is lower than the predetermined pressure Pd or the maximum holding pressure Pm when the cage CA is moved up and down, the cage settling prevention device 7 is operated and supplied to the return oil to increase the return pressure. Let
Hereinafter, an example in which the set pressure of the relief valve 7e is set to the predetermined pressure Pd will be described. However, the control is similarly performed when the maximum holding pressure Pm generated at the time of no load or maximum loading is set as described above. do it.
In the third embodiment, as described above, the settlement prevention relief valve 7e is an electromagnetic type using a solenoid (not shown), and the discharge pressure of the settlement prevention hydraulic pump 7a is variably controlled according to a command from the control unit 47. is doing. For example, the pressure regulation of the settling prevention relief valve 7e is variable according to the holding pressure when the holding pressure is in the vicinity of substantially zero (range XL in FIG. 2), and the predetermined pressure Pd is increased as the holding pressure is closer to zero. The above-mentioned high pressure is variable so that the pressure close to the predetermined pressure Pd is output when the holding pressure is closer to the predetermined pressure Pd.

In the hydraulic circuit 1A, when the cage Ca rises, the control unit 47A measures the pressure of the return oil by the raising pressure sensor 45, and when the measured pressure is less than the predetermined pressure Pd, the cage settlement prevention device 7 prevents settlement. The electric motor 7b is started.
The sinking prevention electric motor 7b rotates the sinking prevention hydraulic pump 7a to discharge the pressure oil, and the pressure oil is adjusted to a predetermined pressure Pd corresponding to the loaded load Wt by the settlement prevention relief valve 7e to prevent the settlement. It is fed to the descending pipe 31 through the check valve 7c.
The adjusted pressure oil of the predetermined pressure Pd is added to the return oil of the descending ram type cylinder 61 and enters the ascending control valve 44. The raising control valve 44 raises the return pressure to the predetermined pressure Pd or more, It is controlled to a constant flow rate and returns to the tank 38. At this time, since the ascending ram type cylinder 62 has risen due to the discharge pressure of the ascending pump 35A, the settling prevention check valve 7d is closed, and the settling prevention hydraulic pump 7a is connected to the descending pipe 31. Be sent. Further, the control unit 47A receives the result of measuring the discharge flow rate of the ascending pump 35A by the descending flow meter 51, and controls the flow rate and pressure of the ascending control valve 44 based on the result, so that the ascending speed of the cage CA and The return oil is set to a predetermined pressure Pd.

  On the other hand, when descending, the control unit 47A measures the pressure of the return oil of the ascending ram type cylinder 62 with the descending pressure sensor 55, and when the measured pressure is less than the predetermined pressure Pd, The sinking prevention electric motor 7b is started and controlled in the same manner as in the above-described rise. The pressure oil of the settling prevention hydraulic pump 7a is adjusted to be equal to or higher than a predetermined pressure Pd corresponding to the loaded load by the settling prevention relief valve 7e, and is sent to the ascending pipe 34 through the settling prevention check valve 7d. The adjusted pressure oil of the predetermined pressure Pd is added to the return oil of the ascending ram type cylinder 62 and enters the lowering control valve 54. The lowering control valve 54 raises the return pressure to the predetermined pressure Pd or higher. It is controlled to a constant flow rate and returns to the tank 38.

  As a result, the raising ram cylinder 62 reaches the predetermined pressure Pd, and the lowering ram cylinder 61 receives the pressure oil from the lowering pump 32A corresponding to the loaded weight Wt of the cage CA and rises to the predetermined pressure Pd. Yes. Further, the control unit 47A receives the result of measuring the discharge flow rate of the descending pump 32A by the ascending flow meter 41, and controls the flow rate and pressure of the descending control valve 54 based on the result, so that the descending speed of the cage CA and The return oil is set to a predetermined pressure Pd.

In the above embodiment, the meter-out control has been described. However, even in a general hydraulic circuit for meter-in control, “at least the internal pressure is loaded when riding in a cage and / or when loading a load. It is effective to set the holding pressure at the time of weight or no load, preferably a predetermined pressure equal to or lower than the holding pressure, and the latter hydraulic circuit can also be used. In the above-described embodiment, the holding pressure and the return pressure are measured by the pressure sensors 45 and 55, and the meter-out control is performed by the pressure. However, the load weight Wt is measured by the load cell or the like, and as a result, the pressure is controlled by the control unit 47. And control may be performed based on the pressure.
The hydraulic circuit 1 of the first embodiment uses, for example, a single pump and motor, and a double-acting cylinder 3, and the hydraulic circuit 1A of the second embodiment uses one pump, motor, and ram type cylinder. The combination of the configurations of the first embodiment and the second embodiment can be changed as appropriate. Further, the hydraulic pump of the hydraulic circuit 1 of the first embodiment uses a fixed displacement type, but a variable displacement type may be used, or a variable rotation type electric motor may be used as the electric motor.
Although the hydraulic cylinder 1 of the present invention has been described using a hydraulic elevator, it is needless to say that it can be used for other hydraulic cargo handling machines.

1 is a hydraulic circuit diagram of a hydraulic elevator according to Embodiment 1 of the present invention. It is a figure explaining the holding pressure which arises in an extension room and a reduction room at the time of a stop of a double action cylinder concerning Example 1 of the present invention. It is a figure explaining the relationship of the pressure which arises in a cylinder by the meter-out which concerns on Example 1 of this invention. It is a block diagram of the elevator cage which concerns on Example 2 of this invention, a ram type | mold cylinder, and balance weight. It is a hydraulic circuit diagram of the hydraulic elevator of 2nd Example which concerns on this invention. FIGS. 6A and 6B are diagrams illustrating a relationship between pressures generated in a cylinder by meter-out according to the second embodiment of the present invention, in which FIG. It is a hydraulic circuit diagram of a hydraulic elevator using a conventional hydraulic cylinder. It is side surface sectional drawing which shows a part of conventional hydraulic cylinder.

Explanation of symbols

1, 1A ········ Hydraulic circuit of hydraulic elevator 3 ··· Double acting cylinder 5, 5A ······ Hydraulic device for lifting 7 ···・ ・ ・ ・ ・ Cage sinking prevention device 9 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Level correction device 11 ・ ・ ・ ・ ・ ・ ・ ・ Automatic emergency cage lifting device 13 ・ ・ ・ ・ ・ ・ ・ ・Emergency manual cage lifting device 21 ... Cylinder tube 22 ... Piston rod 23 ... Tube piston 32, 32A ...・ Lowering hydraulic pump 35, 35A... Lifting hydraulic pump 41... Lifting flow meter 44. ············ Up pressure sensor 51 ······················ Lower flow meter・ ・ ・ ・ ・ ・ ・ ・ ・ Lower pressure sensor 61 ・ ・ ・ ・ ・ ・ Lower ram cylinder 62 ・ ・ ・ ・ Up ram cylinder 64 ・ ・ ・ ・ ・ ・... Rising suction valve 65 ..... Lowering suction valve Wb ... ... Balance weight CA ...

Claims (9)

A hydraulic circuit of a hydraulic elevator in which the hydraulic power of a cylinder for raising and lowering a person and / or a cargo loading cage is reduced to about 1/2 by adding a balance weight to reduce the power of a drive source, and at least boarding the cage A double-acting cylinder or a ram type cylinder whose internal pressure is set to a maximum load weight or a holding pressure at the time of no load, preferably a predetermined pressure equal to or lower than the holding pressure when loading and / or loading The hydraulic circuit of the hydraulic elevator.   A hydraulic circuit of a hydraulic elevator in which the hydraulic pressure of a cylinder for raising and lowering a person and / or a luggage-carrying cage is reduced to about 1/2 by adding a balance weight to reduce the power of a drive source, and is connected to the cage Balance weight, ram rod protrusions in the elevator machine room, cylinder tube is attached to the lowering ram type cylinder, ram rod protrusions in the cage, and cylinder tube in the elevator machine room A hydraulic circuit for a hydraulic elevator, characterized in that the hydraulic circuit includes a lift ram cylinder.   A hydraulic circuit of a hydraulic elevator in which the hydraulic pressure of a cylinder for raising and lowering a person and / or a luggage-carrying cage is reduced to about 1/2 by adding a balance weight to reduce the power of a drive source, and is connected to the cage Balance weight, ram rod projections are installed in the elevator machine room, cylinder tube is attached to the lowering ram type cylinder, ram rod projections are installed in the cage, and cylinder tubes are installed in the elevator machine room. The cylinder has an internal pressure that is at least the maximum loading weight or no-load holding pressure, preferably at least a predetermined pressure that is equal to or lower than the holding pressure. A hydraulic circuit for a hydraulic elevator, characterized in that   4. A settling prevention device is provided, wherein the cylinder hydraulic pressure is set to a maximum loading weight or a holding pressure at the time of no load, preferably a predetermined pressure equal to or lower than the holding pressure. A hydraulic circuit for a hydraulic elevator according to claim.   A settling prevention device is a pair of check valves that are connected to each of the lifting chambers of a double-acting cylinder or a ram type cylinder, and a settling prevention unit that supplies pressure oil to the lifting chambers of the double acting cylinder or the ram type cylinder via the check valve A hydraulic pump, an electric motor for preventing settlement, which drives the hydraulic pump for preventing settlement, a position sensor for detecting the stop of the cage, a switch for raising and lowering called on a predetermined floor on which a person and / or a load is loaded on the cage, and opening an elevator door A signal output means for outputting a signal from any one of a switch, a timer, a pressure sensor for detecting the pressure in the cylinder lifting chamber, or a human proximity detection sensor for detecting the approach of a person on the cage, and the signal output means Maximum loading weight of control means that drives the electric motor to prevent the sinking in response to the signal and the pressure oil of the hydraulic pump to prevent the sinking supplied to the cylinder Other holding pressure at no load, preferably hydraulic oil pressure circuit of an elevator according to claim 4, characterized in that it consists of a relief valve which at least pressure under the holding pressure or.   The anti-sag device receives a control valve that controls the amount of return oil from the double-acting cylinder or ram type cylinder to the tank, a pressure sensor that detects the pressure of return oil from the cylinder to the tank, and a signal from the pressure sensor. It comprises a control means for outputting a command to the control valve, restricting the return oil to the tank, and setting the cylinder hydraulic pressure to a maximum load weight or a holding pressure at no load, preferably a predetermined pressure equal to or lower than the holding pressure. The hydraulic circuit for a hydraulic elevator according to claim 4.   A position sensor that detects the stop position of the cage, a level hydraulic pump that supplies pressure oil that corrects the cage stop position according to the signal from the position sensor to a double-acting cylinder or a ram type cylinder, and a level hydraulic pump 7. A level correction apparatus comprising: a level electric motor for driving and a control means for driving the level electric motor in response to a signal from the position sensor. A hydraulic circuit for a hydraulic elevator according to claim.   The emergency hydraulic pump that supplies pressure oil to the double-acting cylinder or ram cylinder according to the signal from the emergency switch, the emergency electric motor that drives the emergency hydraulic pump, and the emergency switch It has an emergency automatic cage lifting / lowering device comprising a control means for driving an emergency electric motor in response to a signal and a switching valve for supplying pressure oil of an emergency hydraulic pump to any of the lifting / lowering chambers of the cylinder. The hydraulic circuit for a hydraulic elevator according to any one of claims 1 to 7, wherein the hydraulic circuit is a hydraulic elevator.   An emergency manual hydraulic pump that supplies pressure oil to a double-acting cylinder or a ram type cylinder at the time of an emergency stop of the cage, and a manual type that supplies pressure oil from one of the emergency manual hydraulic pumps to either the cylinder lift chamber The hydraulic circuit for a hydraulic elevator according to any one of claims 1 to 8, further comprising an emergency manual cage lifting device including a switching valve.

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