JPH04333484A - Fluid pressure elevator - Google Patents

Abstract

PURPOSE:To efficiently utilize a building by miniaturizing an electric power unit through reduction of driving power of a fluid pressure elevator, and minifying an installation space through miniaturization of a fluid pressure control device. CONSTITUTION:It is constituted out of a fluid pressure cylinder 1 to drive an elevator cage 7, an energy storing device 20 to store energy balancing with energy in the load condition corresponding to a half of rated load of an elevator, and a fluid pressure control device 10 to move working fluid between the fluid pressure cylinder 1 and the energy storing device 20 while controlling flow. The fluid pressure energy for a fluid pressure elevator is stored in the energy storing device 20, pressure fluid is moved between the fluid pressure cylinder 1 and the energy storing device 20 with the fluid pressure control device 10, and hence the elevator cage 7 is controlled to ascend or descend.

Description

[Detailed description of the invention]

0001

[Industrial Application] The present invention increases or decreases the speed of a car driven directly or indirectly by a hydraulic cylinder by controlling the flow rate of pressure fluid supplied to or discharged from the hydraulic cylinder. This invention relates to a type of hydraulic elevator.

0002

[Background Art] When raising a car, a fluid pressure pump generates enough fluid pressure to support the weight of the car including its load, and a flow rate control valve controls the flow rate of high-pressure fluid directly.
Alternatively, the car is raised by supplying it to a fluid pressure cylinder while controlling the rotation speed of the pump by changing it. When lowering the car, the flow rate of high-pressure fluid is controlled either directly by a flow control valve or by changing the rotational speed of a pump while being discharged from a fluid pressure cylinder to lower the car. -306179).

0003

[Problems to be Solved by the Invention] When raising a car, the fluid pressure generated by the pump is the entire weight of the car including the load, and the energy required to drive the hydraulic pump is large. Therefore, the required power supply equipment or drive device becomes large. When lowering a car, the potential energy of the car's position is directly converted into heat energy by a control valve or motor and then discarded. This may lead to an increase in the temperature of the fluid. That is, the energy supplied during upward movement is converted into heat and discarded during downward movement, resulting in a large energy loss.

The first object of the present invention is to improve the energy efficiency and reduce the driving power when driving a hydraulic elevator, and the second object is to reduce the size of the power supply equipment or drive device. This also reduces the installation area of the elevator and the drive device that drives it.

[0005]

In the present invention, an energy storage device and a fluid pressure cylinder are coupled via a fluid pressure pump or a fluid pressure control valve, and a fluid flow rate between the energy storage device and the fluid pressure cylinder is provided. to control car speed. That is, energy corresponding to the sum of the weight of the car and half the weight of the rated load is stored in advance in the energy storage device as fluid pressure. When actually driving the hydraulic elevator, the hydraulic pump supplies and discharges energy corresponding to the energy difference between the hydraulic cylinder and the energy storage device, thereby driving the hydraulic elevator with the minimum amount of energy. In addition, in order to reduce the installation area of the drive device,
This can be solved by providing a separate energy storage device or by providing a tube around the outer periphery of the fluid pressure cylinder to form a double tube.

[0006]

[Operation] When actually driving a hydraulic elevator, the difference in energy between the hydraulic cylinder that drives the car and the energy storage device is less than half of the rated load, if losses along the way are ignored. Furthermore, depending on the number of passengers, the energy of the hydraulic cylinder may be less than the energy storage device (the energy of the energy storage device alone can drive the hydraulic cylinder), or vice versa (the fluid pressure pump is supply the missing energy). Therefore, the average energy required to drive the hydraulic elevator is further reduced. According to the present invention, since the required power is reduced, the power supply equipment and drive device become smaller, and the amount of fluid is also reduced, and the drive device can be made smaller, so that the installation area of the elevator and its drive device can be reduced.

[0007]

[Embodiment] An embodiment of the present invention is shown in FIG. The fluid pressure elevator according to the present invention includes a car 7, a fluid pressure cylinder 1
, a fluid pressure control device 10, and an energy storage device 20. The car 7 is guided by rails 8 and supported by a hydraulic cylinder 1 via a rope 6 and a pulley 4. The fluid pressure cylinder 1 is composed of a cylinder 2 and a plunger 3 having a pulley 4 at the top thereof, and the plunger 3 expands and contracts by supplying and discharging working fluid to the cylinder 2. Further, the fluid pressure cylinder 1 is made of a double cylinder, and a piston 3 is slidably inserted into the inner cylinder 2, so that it functions as a fluid pressure cylinder. The outer energy storage device 20 is
By separating the fluid chamber 2d and the gas chamber 2f with the free piston 2e, the free piston 2e acts as an accumulator and stores fluid pressure energy. Therefore, the control valve 14 is in communication with the fluid chamber 2d of the outer energy storage device 20, and fluid pressure energy flows from the fluid chamber 2c of the inner cylinder 2 through the control valves 13, 14 and the hydraulic pump 12. temporarily stored. The fluid pressure control device 10 includes a fluid pressure pump 12 that can be rotated in forward and reverse directions, a motor 11, and control valves 13 and 14, and controls the flow of fluid between the fluid pressure cylinder 1 and the energy storage device 20. High-pressure gas and high-pressure fluid are sealed in the energy storage device 20, and the pressure energy of the fluid, which is a working medium, is converted into gas pressure energy and stored. When the plunger 3 of the hydraulic cylinder 1 is at the lowest position, the working fluid is injected into the energy storage device 20, and when the car load is half the rated load and the stroke is half the rated stroke, the hydraulic cylinder 1 1 pressure and cylinder 2
The gas chamber 25 is arranged so that the pressure in the first fluid chamber 24 is almost balanced.
Then, the gas tank 23 is filled with gas.

The weight of the car is WC, the load of the car is WL, the weight of the pulley and plunger is Wj, the cross-sectional area of the plunger is Aj, the pressure of the fluid pressure cylinder is pj,
The fluid pressure (pressure in the fluid chamber 2d) of the cylinder of the energy storage device is po, the gas pressure (pressure in the gas chamber 2f) is pa,
The variable volume of the fluid chamber 2c of the fluid pressure cylinder 1 is Vj, and the maximum volume of the fluid chamber 24 of the cylinder 21 is Vo (Vj<Vo).
Let Qp be the flow of fluid from the energy storage device 20 to the fluid pressure cylinder 1, and let Lm be the power supplied from the motor 11 to the fluid pressure pump 12 at this time. The speeds of the plunger 3 and the free piston 2e are vj and va, and the pressure receiving area of the free piston 2e is Ao. If the structure of the fluid pressure elevator is an indirect type as shown in the figure, pj = (2・
(WC+WL)+Wj)/Aj,Lm=Qp・(pj-
po), Qp=Aj·vj=Ao·va. Also,
When the car is at approximately half of its rated stroke, the pressure in the fluid chamber is po≒(2・WC+WL+Wj)/A
j (the amount of gas sealed is not exact, but a rough amount is sufficient). Further, it is sufficient that the amount of working fluid is slightly more than twice the fluctuating volume of the fluid pressure cylinder (Vj + Vo),
It does not require a large tank like conventional ones. Furthermore, since the pressure in the fluid chamber 2d is stored in the gas chamber 2f, the size of the energy storage device 20 is also reduced, making it much smaller than a conventional fluid pressure power unit.

Since the hydraulic elevator of the present invention is constructed as described above, it operates as follows. First, when the car 7 rises: the control valve 14 is opened and the fluid chamber 2d of the cylinder 21 is communicated with the fluid pressure pump 12.
is driven to supply high-pressure fluid to the fluid pressure cylinder 1 via the control valve 13 and push up the car 7 via the rope 6. Speed control of the car 7 is performed by controlling the speed of a motor 11 that drives a fluid pressure pump 12.

Next, when the car 7 is lowered: the control valve 13 is opened to communicate the high pressure fluid in the fluid pressure cylinder 1 to the fluid pressure pump 12, and the fluid pressure pump 12 is driven to open the control valve 1.
4 to the fluid chamber 2 of the energy storage device 20.
d, and using the weight of car 7, lift car 7.
lower. The speed control of the car 7 is executed by controlling the rotation speed of the fluid pressure pump 12 with the motor 13 in the same way as when raising the car.

The hydraulic elevator of the present invention is adjusted as follows. After the elevator is assembled, the hydraulic cylinder 1 and the energy storage device 20 are supplied with working fluid at low pressure. Since the fluid pressure is low, the weight of the car 7 cannot be pushed up. However, the hydraulic cylinder 1 is filled with working fluid. In addition, the energy storage device 2
At 0, there is no force to push the free piston 2e (no gas is sealed), so even if the fluid pressure is low, the free piston 2e is pushed up and the fluid flows into the fluid chamber 2d, which is filled with working fluid. The fluid chambers 2d of the fluid pressure cylinder 1, the fluid pressure control device 10, and the energy storage device 20 are now filled with the working fluid. After that, working gas is filled into the gas chamber 2f at a required pressure.

[0012] With this structure, the required power can be reduced, so that the power supply equipment and the drive device can be made smaller, and the installation area of the drive device can also be made smaller.

FIG. 2 shows another embodiment of the hydraulic cylinder 1 of FIG. 1, with a free piston 2e in the outer cylinder 21.
is removed. When a gas and a fluid are brought into contact with each other and pressurized, a phenomenon occurs in which the gas becomes bubbles and mixes into the fluid. However, if there is no problem with the mixed amount, the number of parts can be reduced and the free piston 2e and cylinder 21
This eliminates the need to process the inner surface of the tube, making production easier.

FIG. 3 is an explanatory diagram of the state of supply and discharge of energy accompanying the operation of the elevator, that is, the relationship between the stroke of the car and fluid pressure. Elevators are used with strokes ranging from 0 to full stroke and pressures ranging from minimum (no load) to maximum (full load). The pressure in the fluid chamber 2d of the energy storage device 20 is expressed as a solid line because the volume of the gas chamber changes depending on the stroke. This slope is the gas chamber 2f.
depends on the volume of , the larger the volume, the smaller the gradient, and the smaller the volume, the larger the gradient. Under a certain load condition (hydraulic cylinder pressure = pj), the following energy is supplied and discharged to raise and lower the car during a full stroke.

In the case of ascending: The car 7 moves from A to C via B. At this time, the fluid chamber 2d of the cylinder 21
The pressure changes from A' to C' via B. That is, as the car 7 rises, the fluid is moved from the pressure line A'BC' to the pressure line ABC. Therefore, energy corresponding to the area surrounded by the ABC line and the A'BC' line is exchanged between the motor 11 and the pump 12. This energy is QP.(pj-po), and the motor 11 absorbs the area ABA' and supplies the area BCC'.

In the case of descent: The car 7 moves from C to A via B. At this time, the fluid chamber 2d of the cylinder 21
The pressure changes from C' to A' via B. That is, as the car 7 descends, the fluid is moved from the pressure C'BA' line to the pressure CBA line. Therefore, energy corresponding to the area surrounded by the CBA line and the C'BA' line is exchanged between the motor 11 and the pump 12. This energy is QP・(pj-po), and the motor 11 has an area B
It absorbs CC' and supplies area ABA'.

Comparing this with the conventional case, when the car 7 moves along line ABC, the motor 11 uses the fluid pressure pump 12 to increase the fluid pressure from atmospheric pressure to the load pressure and sends it to the fluid pressure cylinder 1. supply That is, the area AB
Supply energy equivalent to CDO. In the case of descending, when the car 7 moves along the CBA line, the flow control valve (
(or by the motor 11 and the hydraulic pump 12) the working fluid in the hydraulic cylinder 1 is lowered from the load pressure to atmospheric pressure and discharged to the tank. That is, it absorbs energy corresponding to the area ABCDO.

The amount of energy supplied at this time determines the power of the motor, that is, the size of the power supply equipment, and the amount of energy absorbed determines the amount of heat generated. Therefore, it can be seen that the smaller the amount of energy supplied or absorbed in driving the elevator, the more convenient it is. Conventionally, it was necessary to supply and absorb energy between the load pressure and atmospheric pressure, and the amount was large, but in the present invention, the energy storage device 20 stores energy approximately equivalent to half of the rated load. The amount decreases dramatically.

FIG. 4 shows another embodiment of the present invention. The difference from the embodiment shown in FIG. 1 is the structure of the hydraulic cylinder 1, which is the driving device, and the transmission path of the driving force. The fluid pressure cylinder 1 is composed of a cylinder 2, a piston 3, and a stopper 2a, and while the embodiment shown in FIG. 1 is a push-up type fluid pressure cylinder, this embodiment is a tension type fluid pressure cylinder. A pulley 4 is provided on the top of the piston 3, and a pulley 5 is further provided on the upper part of the lifting path. The rope 6, which is a driving force transmission medium, drives the car 7 via these pulleys. This embodiment is a tension type fluid pressure cylinder, and there is no buckling of the plunger which was a problem with the fluid pressure cylinder of the previous embodiment, so the diameter of the plunger 3 and the fluid pressure cylinder 1 can be made smaller. Therefore, not only the energy storage device 20 but also the fluid pressure control device 10 can be made smaller. That is, it is possible to further reduce the size than the previous embodiment. Further, FIG. 5 is an example in which the free piston 2e is removed similarly to FIG. 2. The operations and the like in both FIGS. 4 and 5 are the same as those in the previous embodiment, so a description thereof will be omitted.

All other embodiments of the invention shown in FIGS. 6-9 below are described using a tension-type hydraulic cylinder as the drive device. The effect is similar to that of a push-up hydraulic cylinder.

FIG. 6 shows an embodiment of the present invention, in which an accumulator 27 as a pressure storage device is provided separately from the fluid pressure cylinder 1 so that it can be installed in the immediate vicinity of the fluid pressure cylinder 1 or at another location. This is what I did. The operation and the like are the same as in the embodiment shown in FIG. 1, and it is equivalent to the cylindrical accumulator in FIG. 1 being changed to a cylindrical shape in this embodiment. According to this method, the accumulator 27 is easy to manufacture, and even if a commercially available one is purchased, it can be arbitrarily selected according to the capacity of the fluid pressure cylinder 1 to be used. Further, since the flow paths 15a and 15b can be guided arbitrarily, the accumulator 27 can be installed in an empty space, providing flexibility.

FIG. 7 shows a second embodiment of the present invention, and FIG.
The accumulator 27 used for this is arranged at the bottom of the fluid pressure cylinder 2. According to this embodiment, since the empty space (underground) below the fluid pressure cylinder 2 can be used, the space for installing the accumulator 27 can be secured by digging into the ground.

FIG. 8 shows a third embodiment of the present invention, in which an energy storage device 20 is installed within the plunger 3. The energy storage device 20 of this embodiment includes a piston 3a
, 3b and the plunger 3 are configured with a fluid chamber 24b, a fluid chamber 24a, and a gas chamber 25, and the fluid chamber 24a and the gas chamber 25 are separated by a free piston 29 that is slidably movable. The gas chamber 25 is arranged such that when the load of the car is half the rated load and the stroke is half the rated stroke, the pressure in the fluid pressure cylinder 1 and the pressure in the fluid chamber 24 of the cylinder 21 are almost balanced. 25 and the gas tank 23 are filled with gas. Fluid chamber 24a and fluid chamber 2
4b is filled with working fluid and communicated through a communication hole 40. Therefore, when the car is raised, the stored pressure energy and the pump send the fluid in the fluid chambers 24a and 24b to the fluid chamber 2c, so the pressure in the gas chamber 25 decreases and the free piston 29 moves downward. I will do it. In the case of lowering the car, the opposite is true; the working fluid in the fluid chamber 2c is supplied to the fluid chamber 24b by the pressure energy due to the weight of the car and the load, and by the pump, and then flows from the fluid chamber 24b through the communication hole 40 to the fluid chamber 24a. It also flows into At this time, since pressure is accumulated in the gas chamber 25, the pressure increases. Although the free piston 29 is provided in this embodiment, it may be removed as in FIGS. 2 and 5. Further, the flow path 15b needs to be connected at a position where it is always communicated with the fluid chamber 24b, taking into consideration the stroke of the piston. According to this embodiment, a very compact fluid pressure cylinder can be realized.

FIG. 9 shows a fourth embodiment of the present invention, in which a pressure storage device is installed inside the cylinder 2. In this embodiment, a portion surrounded by the pistons 3a and 3b, the cylinder 2, and the plunger 3 is divided into a fluid chamber 24 and a gas chamber 25 by the free piston 2e, thereby forming a pressure storage device. Similar to the embodiment shown in FIG. 8, the upward movement of the car is realized by supplying the working fluid in the fluid chamber 24 to the fluid chamber 2c, and the downward movement of the car is realized by supplying the working fluid in the fluid chamber 2c to the fluid chamber 24. do. The free piston 2e of this embodiment may also be removed if it does not affect the inclusion of air bubbles. Although this embodiment also requires consideration of the connection position of the flow path 15b as in FIG. 7, it is possible to realize a compact fluid pressure cylinder.

[0025]

[Effects of the Invention] The hydraulic elevator of the present invention has the structure and operation as described above, and has the following effects. That is, the driving power of the fluid pressure control device that drives the car can be significantly reduced, and the amount of working fluid is also reduced, so the fluid pressure control device can be made smaller. This shows that the power supply equipment can be downsized and the installation area of the elevator can be reduced, which means that the efficiency of building use can be improved.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an embodiment of a hydraulic elevator of the present invention.

FIG. 2 is an explanatory diagram of another embodiment of the fluid pressure cylinder of the embodiment shown in FIG. 1;

FIG. 3 is a stroke pressure diagram accompanying elevator operation.

FIG. 4 is an explanatory diagram of another embodiment of the hydraulic elevator according to the present invention.

FIG. 5 is an explanatory diagram of another embodiment of the fluid pressure cylinder of the embodiment shown in FIG. 3;

FIG. 6 is a block diagram of an embodiment of an energy storage device for a hydraulic elevator according to the present invention.

FIG. 7 is a block diagram of a second embodiment of the energy storage device for a hydraulic elevator according to the invention;

FIG. 8 is a block diagram of a third embodiment of an energy storage device for a hydraulic elevator according to the present invention.

FIG. 9 is a block diagram of a fourth embodiment of an energy storage device for a hydraulic elevator according to the present invention.

[Explanation of symbols]

1... Fluid pressure cylinder, 2... Cylinder, 2c, 2d... Fluid chamber, 2e... Free piston, 2f... Gas chamber, 3... Plunger or piston, 4... Pulley, 6... Rope, 7... Car, 8... Rail, DESCRIPTION OF SYMBOLS 10... Fluid pressure control device, 11... Motor, 12... Pump, 13, 14... Control valve, 15a, 1
5b...Flow path, 20...Energy storage device, 21...Cylinder.

Claims (1)

[Claims] 1. A fluid pressure elevator that controls the flow rate of fluid supplied to or discharged from a fluid pressure cylinder to control the speed of a car supported directly or indirectly at the top thereof, wherein the magnetic pressure cylinder and a fluid pressure energy storage means, the energy storage means and the fluid pressure cylinder are coupled via a fluid pressure control device including a fluid pressure pump and a fluid pressure control valve, and the fluid pressure A fluid pressure elevator characterized in that a control device causes fluid to be reciprocated between the energy storage means and the fluid pressure cylinder to expand and contract the fluid pressure cylinder to raise and lower the car.