JPH0121070B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention provides a method for raising or lowering a plunger by supplying or discharging pressure fluid to a hydraulic ram, and for directly or indirectly coupling a passenger car to the plunger. This invention relates to a hydraulic elevator of the type that raises or lowers. [Prior Art] In the flow control valve used in this type of fluid pressure elevator, a large number of throttle resistors are provided in the pilot circuit that controls the main control valve, and the main control valve is operated according to a preset sequence. The flow rate was controlled by This technology is described in, for example, JP-A-59-
There is a publication number 36077. [Problems to be Solved by the Invention] In the above conventional technology, the fluid resistance of the throttle section that controls the operation of the main control valve changes with changes in the pressure acting on the working fluid and the fluid temperature, resulting in loss of controllability. was. An object of the present invention is to provide a high-performance hydraulic elevator equipped with a flow control valve that exhibits constant controllability even when fluid pressure or fluid temperature changes. [Means for Solving the Problem] The above object is to increase the speed of a car connected directly or indirectly to a fluid pressure cylinder by controlling the flow rate of pressure fluid supplied to or discharged from the fluid pressure cylinder using a flow control valve. In the fluid pressure elevator to be controlled, the flow control valve includes a rise control valve provided between a pump port and a tank port that communicate with a fluid pressure source, and a cylinder port and the tank port that communicate with the fluid pressure cylinder. a first ascending pilot valve provided between a pressure chamber of the ascending control valve and a flow path connected to the pump port; a pressure chamber of the ascending control valve and the tank; a second ascending pilot valve provided between the ascending port and the ascending pilot valve, which controls the pressure in the pressure chamber of the ascending control valve;
a first descending pilot valve provided between the pressure chamber of the descending control valve and a flow path communicating with the cylinder port; and a first descending pilot valve provided between the pressure chamber of the descending control valve and the tank port. The second ascending pilot valve includes a descending control valve that controls the pressure in the pressure chamber of the descending control valve, and the ascending pilot valve and the descending pilot valve energize their respective solenoids in proportion to the command signal. This is achieved by being controlled by the signal. [Operation] Since pilot valves are provided on the upstream and downstream sides of the ascending control valve and descending control valve, when supplying or discharging pilot fluid, it is possible to control with only one pilot valve on the upstream side or downstream side. can. Therefore, the supply and discharge of the pilot flow can be arbitrarily controlled, and the control characteristics of the main valve that change depending on the load and fluid temperature can be compensated for, and good control characteristics can be obtained. [Examples] Examples of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a diagram showing the configuration of a fluid pressure elevator. In a hydraulic elevator, a hydraulic cylinder 10
The speed of the plunger 104 is controlled by controlling the pressure fluid supplied to or discharged from the plunger 2. The car 101 is directly or indirectly coupled to the top of the plunger to raise or lower the car. The figure shows an indirect type, in which the car 101 is driven via a pulley 105 and a rope 106 provided at the top of the plunger 104. The flow control valve 1 controls the flow rate of high pressure fluid from the fluid pressure source 103 to the fluid pressure ram 102 or from the fluid pressure ram 102 to the fluid pressure source 103, respectively. FIG. 2 is a sectional view showing details of the flow control valve 1 according to the present invention. The valve body 2 includes a rise control valve 10 for controlling the rise speed and a fall control valve 3 for controlling the fall speed.
0, a check valve 20 for preventing leakage of pressure fluid from the fluid pressure ram, pilot valves 40, 50, 60, 70 for controlling the ascending and descending control valves 10, 30, and further communicating with the fluid pressure source 103. A pump port 5, a tank port 6, a cylinder port 7 communicating with the hydraulic ram, etc. are provided. The rise control valve 10 is provided between a flow path 81a connected to the pump port 5 and a flow path 81a connected to the tank port, and is connected to a fluid chamber 1 provided in the valve body 2.
6, a poppet 11, a spring 14, etc. The poppet 11 has a skirt portion 12 and a notch 13 provided in the skirt portion. The poppet 11 is constantly pushed upward by a spring 14, and communicates the two flow paths 81a and 82a through the notch 13 provided in the skirt portion 12 and the fluid chamber 16. When fluid is supplied, the poppet 11 is pushed down, reducing the communication area of the notch 13 and finally sealing it. The normal positions of the stopper 15 and poppet 11 are restricted, and the communication area of the notch 13 at this time is set. The first pilot valves 40 and 50 for raising control the fluid pressure in the pressure chamber 17 of the raising control valve 10.
The first ascending pilot valve 40 is a normally closed valve that is provided between the flow path 81a and the pressure chamber 17 and communicates with each other through flow paths 84 and 85a. The second ascending pilot valve 50 is provided between the pressure chamber 17 and the tank port 6, communicates with each other through channels 85b and 86, and is a normally open valve. These pilot valves 40, 50 have valve bodies 41, 5
1. Spring 42, 52 that presses the valve body and solenoid 4
The solenoid is driven by a pulse train signal. These valves are provided in the pilot body 3. The descending control valve 30 is provided between the fluid pressure port 7 and the tank port 6, and is composed of a fluid chamber 36 provided in the valve body 2, a poppet 31, a spring 34, and the like. The poppet 31 has a skirt portion 32 and a notch 33 provided in the skirt portion. The poppet 31 is constantly pushed downward by the spring 34 and the fluid pressure acting on the pressure chamber 37 in the upper part of the poppet, and when the pressure fluid in the pressure chamber 37 is removed, it is pushed upward by the fluid pressure acting on the fluid chamber 36. Thereby, the communication area of the notch 33 provided in the skirt portion is increased from zero, and the cylinder port 7 and the flow path 82b are communicated with each other. The stopper 35 limits the amount of movement of the poppet 31 when it moves upward, and sets the communication area of the notch 33. The descending pilot valves 60 and 70 are the descending control valve 3.
The fluid pressure in the pressure chamber 37 at 0 is controlled. 1st for descending
The pilot valve 60 has a flow path 83 connected to the fluid chamber 36.
It is a normally open type valve, which is provided between the pressure chamber 37 and the pressure chamber 37, and communicates with each other through flow paths 87 and 88a.
The second descending pilot valve 70 is provided between the pressure chamber 37 and the tank port 6, communicates with each through channels 88b and 86, and is a normally closed valve. These pilot valves 60 and 70 each have a valve body 6
1, 71, consists of springs 62, 72 that push the valve body, and solenoids 63, 73, and is driven by a pulse train signal. These pilot valves are provided in a pilot valve body 4. The check valve 20 is connected to a flow path 8 connected to the pump port 5.
1b and a flow path 83 connected to the cylinder port 7, and is composed of a poppet 21 and a spring 23. The poppet 21 has a guide rod 22 which is guided by a guide 24 provided on the valve body 2 and is slidable. The check valve 20 connects the flow path 81b to the flow path 8.
The structure allows the flow to flow to the third point to be a free flow, and prevents the opposite flow. The pilot valve solenoid is driven by a pulse signal of a specific frequency and width according to the command. Third
An example of a drive circuit for the solenoids 43 (53, 63, 73) shown in the figure is shown. A command generation circuit 110 generates a command corresponding to the elevator operation pattern, and a drive circuit 113 compares the command signal with an AC signal of a specific frequency from an oscillation circuit 112 (usually a triangular wave or sawtooth wave signal). Then, a pulse signal train with a width corresponding to the command is generated and supplied to the solenoid to drive it. Since the flow control valve provided in the hydraulic elevator of the present invention has the above-described structure, it operates as follows. First, when the car 101 is rising, the fluid pressure source 10
If pump 3 is driven, high pressure fluid will flow through flow control valve 1.
It flows out from the notch 13 in the skirt of the rise control valve 10 to the tank port 6. If the elevator operating speed pattern is generated from the command circuit, the drive circuit 113
Signals with corresponding pulse widths are sent to the solenoids 43 and 53, respectively, and the solenoids are driven. Therefore, the pressure fluid from the flow path 81a is supplied to the pressure chamber 17 and pushes the poppet 11 downward, so the communication area of the notch 13 is reduced, the fluid pressure in the flow path 81a increases, and finally the check valve 2
Push open poppet 21 of 0 and open cylinder port 7.
High-pressure fluid flows into the fluid pressure ram 102 via the ram 102, pushes up the plunger 104, and lifts the car 101.
to rise. Pilot valve solenoid 43,5
3 is supplied with a signal having a pulse width corresponding to the running speed pattern of the hydraulic elevator, the pilot valve 40 supplies pressure fluid to the pressure chamber 17, and the pilot valve 50 discharges pressure fluid from the pressure chamber 17. do. A pressure P ₁ is applied to the poppet 11 of the rise control valve 10 from the fluid chamber 16 in an area of (A ₂ −A ₁ ).
From the pressure chamber 17, pressure P ₂ acts on the area of A ₂ ,
A force F=(A ₂ −A ₁ )P ₁ −A ₂ P ₂ acts on the poppet in an upward direction. Therefore, by controlling _P2 , the poppet position, that is, the communication area of the notch 13 can be controlled. When the poppet 11 is pushed down, the pilot valve 40 supplies pressure fluid to the pressure chamber 17, and in the opposite case, the pilot valve 50 discharges the pressure fluid. As a result, the flow rate of fluid supplied to the fluid pressure ram 102 can be arbitrarily controlled, and the ascent of the elevator can be controlled. In the case of descending, the descending control valve 30 is controlled by the pilot valves 60 and 70 in the same manner as in the case of ascending.
That is, by inputting a pulse train signal to the solenoid 73, the pilot fluid pressure in the fluid chamber 73 is discharged, and when the valve poppet 31 is raised, the fluid flow area of the notch 33 provided in the valve skirt portion 32 is increased. By inputting a pulse train signal to the solenoid 63, pilot fluid pressure in the fluid chamber 37 is supplied to lower the valve poppet 31 and reduce the fluid flow area. This controls the flow rate of fluid discharged from the hydraulic ram 102 and controls the speed of the car 101. FIG. 3 shows the method of driving the pilot valve solenoid as described above, and shows the command generation circuit 110.
generates the elevator running pattern. The drive circuit 113 generates a pulse train signal of a specific frequency having a width proportional to the magnitude of this command. This compares the specific frequency signal from the oscillator 112 with the running pattern signal to generate a pulse train signal of a specific frequency. By doing so, the flow rate through the pilot valve and the command from the generation circuit 110 are approximately proportional, and the flow rate supplied to or discharged from the hydraulic ram 102 can be controlled. Next, the command signal generated by the generation circuit 110 will be explained. 4th signal pattern to solenoid
As shown in the figure. First, in the case of ascent, when accelerating, the excitation pulse width of the solenoid 53 is widened so that the pilot valve 50 is almost fully closed.
By increasing the excitation pulse width of the rise control valve 1,
0 fluid chamber 17 is supplied with pilot fluid, and this valve gradually closes. Solenoid 4 when decelerating
By narrowing the pulse width of 3, bringing the pilot valve 40 into a nearly fully closed state, and narrowing the excitation pulse width of the solenoid 53, the pilot fluid is discharged from the fluid chamber 17 and the rise control valve gradually opens. . At the time of landing, the pulse width of the solenoid 53 is widened again to bring it into a state close to fully closed, so that the pocket 11 maintains its current position and the car rises at a constant speed. The same goes for descending; when accelerating, the valve with a wide excitation pulse width of the solenoid 63 is brought close to fully closed, and as the excitation pulse width of the solenoid 73 is gradually widened, the fluid chamber of the descent control valve is closed. 37 of the pilot fluid is discharged, and the flow area of the control valve 30 becomes wider. During deceleration, the excitation pulse width of the solenoid 73 is narrowed to keep the pilot valve 70 in a nearly fully closed state, and the excitation pulse width of the solenoid 63 is narrowed. This causes the poppet 31 to gradually close and decelerate the car. In the case of landing on the floor, the pulse width of the solenoid 63 is widened again to bring the pilot valve 60 close to fully closed, so that the poppet 31 maintains its current position and the car descends at a constant speed.

〔Effect of the invention〕

According to the present invention, since the fluid passage area of the pilot valve that controls the operation of the main control valve is made variable, constant running characteristics can always be obtained even if the load conditions and temperature conditions of the elevator change. Can be done.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the configuration of a fluid pressure elevator according to the present invention, FIG. 2 is a sectional view showing an embodiment of a flow control valve according to the present invention, and FIG. 3 is a diagram showing a solenoid of a pilot valve according to the present invention. FIG. 4 is a diagram illustrating a signal pattern to the solenoid of the pilot valve according to the present invention, and FIG. 5 is a diagram showing a circuit for driving the solenoid of the pilot valve according to another embodiment of the present invention. FIG. 1...Flow control valve, 102...Fluid pressure ram, 10...
Rise control valve, 20...Check valve, 30...Descent control valve, 40, 50, 60, 70...Pilot valve, 1
1,21,31...poppet, 13,33...notch, 41,51,61,71...valve body, 43,5
3,63,73...Solenoid.

Claims (1)

[Claims] 1. In a fluid pressure elevator that controls the speed of a car connected directly or indirectly to a fluid pressure cylinder by controlling the flow rate of pressure fluid supplied to or discharged from the fluid cylinder by a flow control valve, the flow rate control valve a rise control valve provided between a pump port and a tank port communicating with a fluid pressure source; a fall control valve provided between a cylinder port and the tank port communicating with the fluid pressure cylinder; a first ascending pilot valve provided between a pressure chamber of the control valve and a flow path connected to the pump port; and a second ascending pilot valve provided between the pressure chamber of the ascending control valve and the tank port. a rising pilot valve that controls the pressure in the pressure chamber of the rising control valve; and a first descending pilot valve that is provided between the pressure chamber of the descending control valve and a flow path communicating with the cylinder port. The lowering pilot valve comprises a pilot valve and a second lowering pilot valve provided between the pressure chamber of the lowering control valve and the tank port, and the lowering pilot valve controls the pressure in the pressure chamber of the lowering control valve. . A fluid pressure elevator, wherein excitation of the respective solenoids of the ascending pilot valve and the descending pilot valve is controlled by a signal proportional to a command signal.