JP3346808B2 - Hydraulic elevator control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to speed control of a hydraulic elevator.

[0002]

2. Description of the Related Art In a hydraulic elevator equipped with a car driven directly or indirectly by a hydraulic actuator, as shown in FIG. 7, in a rising direction, pressure oil from a pump 96 driven by a motor is supplied to a switching valve 94. , While the pressure oil from the pump 96 is returned to the tank 97 via the flow control valve 93, and the rising speed of the car 92 is increased by the amount of return from the flow control valve 93 to the tank 97. A bleed-off system for controlling is known. When the car descends, the pressure oil of the hydraulic cylinder 91 due to the weight of the car 92 is adjusted by the flow control valve 95 and discharged to the tank 97.

[0003]

However, in the above-described conventional control device, the car 92 is supplied with pressurized oil due to an increase in frictional resistance due to aging of the hydraulic cylinder 91 or a change in the weight of the car 92. Does not rise immediately and begins to operate when the hydraulic oil pressure exceeds the load. At this time, while the frictional resistance of the hydraulic cylinder 91 is drastically reduced, the command flow rate to the flow control valve 93 is sufficiently large, so that the flow rate of the hydraulic oil applied to the hydraulic cylinder 91 becomes excessive, as shown in FIG. In some cases, an impact was generated when the elevator was started.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a hydraulic elevator control device which prevents a shock generated at the time of starting a car and suppresses fluctuations in speed.

[0005]

The present invention relates to a hydraulic elevator equipped with a hydraulic actuator 50 for driving a car 2 in FIG. 1, and a control valve 60 for controlling hydraulic oil to the hydraulic actuator 50; Means 51 for detecting the pressure of the hydraulic oil applied to the hydraulic actuator 50; means 52 for detecting the flow rate of the hydraulic oil applied to the hydraulic actuator 50; and means 5 for presetting the pressure according to time.
3, a means 54 for generating a drive signal for the control valve 60 from the pressure of the setting means 53 and the detected value of the pressure, a means 55 for presetting a flow rate according to time, and a setting means 55
Means 56 for generating a drive signal for the control valve 60 from the flow rate of the oil and the detected value of the flow rate;
Means 58 for comparing a flow rate set in advance to determine the start of operation of the eta, means 57 for switching the drive signal based on the comparison result, and control based on the output of the switching means 57. Means 59 for driving the valve 60.

[0006]

Therefore, the start of operation of the hydraulic actuator is determined based on a preset flow rate, and control is performed based on a preset pressure pattern until the start of operation of the hydraulic actuator. The speed of the car is controlled based on a preset flow rate. It suppresses sudden fluctuations in load pressure due to a sudden decrease in frictional resistance immediately after the start of the operation of the hydraulic actuator, starts the car smoothly without giving an impact to the car, and performs stable speed control.

[0007]

FIG. 2 shows an embodiment of the present invention.

In FIG. 2, reference numeral 2 denotes an elevator car which is vertically slidably supported inside a building (not shown). The elevator car 2 is supported by a hydraulic cylinder 1 and driven vertically. You.

The hydraulic oil for driving the hydraulic cylinder 1 is a motor 5
Is supplied by a pump 6 driven by
Is supplied to the hydraulic cylinder 1 through the check valve 4 for preventing backflow to the pump 6 and the check valve 30 of the solenoid valve 3 driven by the controller 10, while branching from the upstream of the solenoid valve 3. The fluid is returned to the tank 13 via the proportional electromagnetic flow control valve 7 provided in the working oil passage 12.

The proportional electromagnetic flow control valve 7 is connected to a controller 10
And adjusts the operating speed of the hydraulic cylinder 1 to control the speed of the car 2 by adjusting the amount of pressure oil from the pump 6 returned to the tank 13 in the rising direction of the car 2. In the descending direction of the car 2, the speed of the car 2 is controlled by adjusting the pressure oil from the hydraulic cylinder 1 due to the weight and load of the car 2.

A displacement sensor 9 for detecting a valve opening amount (or angle) is housed in the proportional electromagnetic flow control valve 7, and a detection signal of the displacement sensor 9 is sent to a controller 10.

Further, a pressure sensor 8 for detecting the oil pressure of the hydraulic oil passage 12, ie, the load pressure P of the hydraulic cylinder 1, is provided upstream of the proportional electromagnetic flow control valve 7, and the detection signal of the pressure sensor 8 is sent to the controller 10. Sent. The controller 10 calculates the flow rate from the load pressure of the pressure sensor 8 and the valve opening amount of the displacement sensor 9 and controls the proportional electromagnetic flow control valve 7 so that the target flow rate is set based on a preset driving pattern.

To raise the car 2 to a predetermined floor, the solenoid valve 3 is switched to the position of the check valve 30 and the pump 5 is driven by the motor 5 to drive the hydraulic cylinder 1.
Supply pressurized oil to At this time, the proportional electromagnetic flow control valve 7 adjusts the valve opening amount so that the speed of the car 2 becomes a predetermined speed according to the drive pattern to return excess pressure oil to the tank 13, and a flow chart of FIG. After the proportional electromagnetic flow control valve 7 is controlled based on the hydraulic pressure to activate the car 2 based on the hydraulic pressure, the speed of the car 2 is controlled based on the flow rate.

Hereinafter, an example of control by the controller 10 will be described in detail with reference to a flowchart shown in FIG.

The car 2 is driven according to a preset driving pattern shown in FIGS. The driving pattern is such that a pressure control command Pr and a flow control command Qcr for controlling the hydraulic pressure P supplied to the hydraulic cylinder 1 and the cylinder flow Qc by the proportional electromagnetic flow control valve 7 are respectively transmitted at time t.
The cylinder flow rate Qc is proportional to the speed of the car 2.

When the raising of the car 2 is started, a timer (not shown) of the controller 10 is reset in S1, and a pressure control command Pr corresponding to a preset pressure control pattern is calculated in S2. That is, FIG.
As shown in (2), a value obtained by multiplying the predetermined coefficient α by the time t is calculated as the pressure control command Pr.

After reading the load pressure P of the hydraulic oil passage 12 from the pressure sensor 8 in S3, the proportional electromagnetic flow control valve 7 is driven in S4 such that the load pressure P becomes a pressure corresponding to the pressure control command Pr. .

Next, in step S5, the valve opening amount is read from the displacement sensor 9, and the hydraulic oil discharged to the tank 13 through the proportional electromagnetic flow control valve 7 from the load pressure P read from the pressure sensor 8 passes through the valve. The flow rate Qb is calculated. Although the calculation of the valve passing flow rate Qb is not described in detail, for example, the opening amount of the proportional electromagnetic control valve 7 is x and the opening area is A
(X), where K is a predetermined coefficient, it can be easily calculated by the following equation.

[0019]

(Equation 1)

Further, based on the calculated valve passing flow rate Qb and the known discharge flow rate Qp of the pump 6, a cylinder flow rate Q indicating the flow rate of the working oil supplied to the hydraulic cylinder 1 is obtained in S6.
c is calculated by the following equation.

[0021] Qc = Qp - In Qb S 7, the cylinder flow rate Qc, which is calculated to compare between the flow rate Q _O previously set, the time t cylinder flow rate Qc is in S8 is less than the predetermined flow rate Q _O After adding the predetermined increment value Δt, the processing from S2 is repeated. On the other hand, if the cylinder flow rate Qc is equal to or more than the predetermined flow rate Q _O , the process proceeds to S9 and subsequent steps.

Here, the predetermined flow rate Q ₀ is set as a flow rate for confirming that the hydraulic cylinder 1 has started to operate, and is set to a value such that Q ₀ ≒ 0 and Q ₀ > 0. You. That is, in S7, the hydraulic cylinder 1
It is detected whether the rise of the car 2 has started in response to the above. If the car 2 is in the stopped state, the hydraulic cylinder 1 is driven by the pressure control of S2 to S4, while the rise of the car 2 is started. Then, the hydraulic cylinder 1 is driven by the flow rate control by the processing of S9 and later described later.

When the operation of the hydraulic cylinder 1 is started, S
After resetting a timer (not shown) of the controller 10 again at 9, as shown in FIG. 5 at S 10, the flow rate command, that is, the valve opening amount of the proportional electromagnetic control valve 7 is set as a function of the time t, and the preset cylinder flow rate command Qcr Is calculated.

Next, in step S11, the valve passing flow rate Qb is set
5, while calculating the valve command flow Qbr for commanding the valve opening amount of the proportional electromagnetic control valve 7 from the cylinder flow command Qcr obtained in S10 by the following equation.

Qbr = Qp-Qcr In S13, the valve command flow rate Qbr is used to instruct the proportional electromagnetic control valve 7 on the flow rate of hydraulic oil that bleeds from the pump 6 to the tank 13, and the car 2 is set to the drive pattern shown in FIG. Raise accordingly.

In S14, it is determined whether or not the car 2 has reached the stop position.
After adding a predetermined increment value Δt of the time t in S15, S10
While the drive of the hydraulic cylinder 1 is continued by the subsequent flow control, if it is at the stop position, the cylinder flow command Qc is
, The proportional electromagnetic control valve 7 is opened to stop the car 2. The determination of the stop position is performed based on a proximity switch (not shown) or the like.

In this manner, as shown in FIG. 6, control based on the load pressure P is performed until the operation of the hydraulic cylinder 1 starts, and after the operation of the hydraulic cylinder 1 starts, the cylinder flow rate Qc The control of the speed of the car 2 thereby suppresses a sudden change in the load pressure P due to a drastic decrease in frictional resistance generated when the hydraulic cylinder 1 starts operating. A sudden increase can be prevented, and the car 2 can be started smoothly without giving an impact to the car 2 and stable speed control can be performed.

In the above embodiment, an example in which the proportional electromagnetic flow control valve 7 is applied as a control valve is disclosed. However, a valve for controlling a flow while estimating a passing flow disclosed in Japanese Patent Application Laid-Open No. 4-210180 is disclosed. Is adopted as the above-described control valve, it is possible to suppress the fluctuation of the speed of the hydraulic cylinder 1 due to the fluctuation of the load and the like, and it is possible to further improve the stability of the speed.

In the above-described embodiment, the displacement sensor 9 is housed in the proportional electromagnetic control valve 7 as a means for detecting the flow rate. However, the flow rate can be easily calculated by using a flow rate sensor instead of the displacement sensor 9. That is, it is possible to accelerate the processing in the controller 10.

[0030]

As described above, according to the present invention, control based on pressure is performed until the hydraulic actuator starts operating, and after the hydraulic actuator starts operating, the speed of the car is controlled by the flow rate. As a result, it is possible to suppress a sudden change in load pressure due to a sudden decrease in frictional resistance immediately after the start of the hydraulic actuator, to prevent a sudden increase in the flow rate applied to the hydraulic actuator, and without giving an impact to the car. It is possible to start smoothly and to perform stable speed control.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims of the present invention.

FIG. 2 is a configuration diagram showing an embodiment of the present invention.

FIG. 3 is a flowchart illustrating an example of control.

FIG. 4 is a graph showing a relationship between a pressure control command Pr and a time t.

FIG. 5 is a graph showing a relationship between a cylinder flow rate command Qcr and a time t.

FIG. 6 is a graph showing the relationship between the cylinder flow Qc or pressure P and time t.

FIG. 7 is a configuration diagram showing a conventional example.

FIG. 8 is a graph showing a relationship between speed or acceleration and time.

[Explanation of symbols]

 Reference Signs List 5 Motor 6 Pump 7 Proportional electromagnetic flow control valve 8 Pressure sensor 9 Displacement sensor 10 Controller 51 Pressure detection means 52 Flow detection means 53 Pressure setting means 54 Drive signal generation means 55 Flow rate setting means 56 Drive signal generation means 57 Switching means 58 Comparison means 59 drive means 60 control valve

Continuation of front page (56) References JP-A-5-310373 (JP, A) JP-A-4-341474 (JP, A) JP-A-3-284587 (JP, A) JP-A-4-210180 (JP) , A) Japanese Utility Model Showa 58-41759 (JP, U) Japanese Utility Model Showa 57-126474 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B66B 1/26 B66B 9/04

Claims (1)

(57) [Claims] 1. A hydraulic elevator equipped with a hydraulic actuator for driving a car, a control valve for controlling hydraulic oil applied to the hydraulic actuator, a unit for detecting a pressure of hydraulic oil applied to the hydraulic actuator, Means for detecting the flow rate of the applied hydraulic oil; means for presetting a pressure according to time; means for generating a drive signal for the control valve from the pressure of the setting means and the detected value of the pressure; Means for presetting the flow rate; means for generating a control valve drive signal from the flow rate of the setting means and the detected value of the flow rate ; determining the flow rate detected value and the start of operation of the hydraulic actuator.
Means for comparing the flow rate with a preset flow rate, a means for switching the drive signal based on a result of the comparison, and a means for driving the control valve based on the output of the switching means. Control device for hydraulic elevator.