JPH0524069B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a flow control device for a hydraulic elevator.

[Prior Art] FIG. 5 shows a conventional descending flow rate control device for a hydraulic elevator. Note that the ascending flow rate control device is omitted.

In FIG. 5, 1 is a hydraulic jack, which is composed of a cylinder 1a and a ram 1b as main parts. 2 is a car, which is attached on the ram 1b. 3 is a control valve casing, 4 is a lid of the casing 3 in which a pilot passage is incorporated, and 5 is a flow control valve, which is composed of a piston part 5a and a spool part 5b, and the spool part 5b has an orifice 5c. It is provided. 6 is a valve seat facing the flow rate control valve 5, 7 is an adjustment stopper that controls the stroke amount of the flow rate control valve 5, 8 is a slow speed adjustment screw, and 8a is slidably inserted into this adjustment screw 8. 8b is a passage bored in the spool 8a; 8c is a compression coil spring that presses the spool 8a against the piston portion 5a of the flow control valve 5; 8d is a compression coil spring;
is a throttle hole provided in the slow speed adjustment screw 8. 9, 10, 11 are variable adjustment screws, 9a, 10
Reference characters a and 11a are throttle holes corresponding to variable adjustment screws 9, 10, and 11, respectively. 12 is a flow control valve 5
13 and 14 are electromagnetic valves, and 15 and 16 are inflow holes and outflow holes separated by a flow control valve 5. 17a is the inflow hole 15 and the throttle holes 9a, 10a
The pilot flow path 17b communicates with the throttle hole 9a.
17c is a pilot flow path connected to the inflow side of the solenoid valve 13 and the back chamber 12 of the flow rate control valve 5; road,
17d is a pilot flow path that communicates with the outflow side of the solenoid valves 13 and 14 and the throttle hole 11a, and 17e is a pilot flow path that communicates with the throttle hole 11a and the outflow hole 16, whereby the pilot flow of the flow rate control valve 5 is controlled. 17 is constructed. Reference numerals 18 and 19 designate a main conduit that communicates with the inflow hole 15 and the cylinder 1a of the hydraulic jack 1, and a main conduit that communicates with the outflow hole 16. Reference numeral 20 designates a tank into which the main conduit 19 opens.

Next, the operation of the conventional flow rate control device configured as described above will be explained.

In FIG. 5, the solenoid valves 13 and 14 are in a demagnetized state,
The flow of pressure oil to the pilot channels 17b, 17c, and 17d is blocked, and the pressure oil in the main pipeline 18 flows through the pilot channel 17a, the throttle hole 9a, the pilot channel 17b, the throttle hole 10a, and the pilot channel 1.
7c, passes through the flow path 8b of the spool 8a from the throttle hole 8d, flows into the back chamber 12 of the flow rate control valve 5, and acts on the piston portion 5a to press the flow rate control valve 5 against the valve seat 6. From the inflow hole 15 to the outflow hole 16
This indicates that the ram 1b of the hydraulic jack 1 is in a stopped state.

The descent start and descent acceleration of the elevator car 2 are performed by simultaneously exciting the solenoid valves 13 and 14.
That is, when the solenoid valves 13 and 14 are simultaneously excited and opened, the pilot flow paths 17b,
17c communicates with the pilot flow path 17d, and the pressure oil in the pilot flow paths 17b and 17c flows into the pilot flow path 17d, the throttle hole 11a, and the pilot flow path 17e, and flows out from the outflow hole 16 through the main pipe 19 to the tank 20. do.

At the same time, the pilot channel 17a is opened from the inflow hole 15.
Pressure oil flows into the pilot channels 17b, 17c via the throttle holes 9a, 10a.

The flow rates of the pilot flow paths 17b, 17c, and 17e are adjusted so that the opening areas of the throttle holes 9a, 10a, and 11a are increased or decreased using the variable adjustment screws 9, 10, and 11, and the relationship is expressed by the following equation. Adjust to.

Q ₁₁ >Q ₉ +Q ₁₀ ... Here, Q ₉ ... Amount of flow from the throttle hole 9a to the pilot flow path 17b (cm ³ /sec) Q ₁₀ ... From the throttle hole 10a to the pilot flow path 17c
(cm ³ /sec) Q ₁₁ ... Outflow amount from the throttle hole 11a to the pilot flow path The left side of the above equation is the flow rate from the pilot flow path 17b, 17.
It is the inflow amount to c, and the right side is the outflow amount. In other words, from the inflow hole 15, the pilot channels 17b, 17
The amount of flow into the pilot flow path 17b,
Adjust the variable adjustment screws 9, 10, and 11 so that the amount of outflow from the outflow hole 17c increases.

The pressure oil having the flow rate difference between the inflow amount and the outflow amount flows from the back pressure 12 of the flow rate control valve 5 to the pilot flow path 17b.
and the passage 8 of the spool 8a of the slow speed adjustment screw 8.
b to the pilot flow path 17c via the throttle hole 8d.
It leaks out. This outflow amount is expressed by the following formula.

Q ₁₂ = Q ₁₁ - (Q ₉ + Q ₁₀ ) ... Here, Q ₁₂ ... From the back pressure 12 to the pilot flow path 17b, 1
At this time, the flow rate control valve 5 is pushed up by the pressure oil in the main pipe line 18 and separated from the valve seat 6, and the spool part 5
The inflow hole 15 and the outflow hole 16 communicate with each other through an orifice 5c drilled in b, and the pressure oil in the cylinder 1a of the hydraulic jack 1 flows out into the tank 20, and the ram 1b descends, causing the car 2 to start descending. . Note that the moving speed of the flow rate control valve 5 is expressed by the following equation, and is a constant speed.

V=4×Q ₁₂ /π×D ² ... However, V...Movement speed of flow control valve 5 (cm/sec) D...External dimension of piston portion 5a (cm) π...Pi...Flow rate control valve As the amount of movement of the car 5 increases, the area of the orifice 5c that opens into the inflow hole 15 increases, so the flow rate of pressure oil returning from the cylinder 1a to the tank 20 increases, and the car 2 accelerates and descends.
The acceleration at this time can be adjusted by changing the opening area of the throttle hole 11a using the variable adjustment screw 11 and changing the flow rate flowing out from the throttle hole 11a.

The flow rate control valve 5 stops when the upper surface of the piston portion 5a hits the adjustment stopper 7 and moves until it is blocked, and since the area of the orifice 5c that opens to the inflow hole 15 is constant, the flow rate from the cylinder 1a to the tank 20 is
The flow rate of the pressure oil returning to 2 becomes constant, and the car 2 continues to descend at a constant high speed. In addition, the spool 8a fitted into the slow speed adjustment screw 8 also moves upward together with the flow rate control valve 5, closing the throttle hole 8d and closing the throttle hole 8d.
This prevents pressure oil from flowing from the pilot flow path 17c to the pilot flow path 17c.

When the car 2 approaches the target floor, the solenoid valve 13 is de-energized and the pilot channels 17b and 1
7d, the pressure oil that has flowed in through the throttle hole 9a has no outlet and flows into the back chamber 12 of the flow rate control valve 5, increasing the pressure in the back chamber 12. When the pressure of the back pressure 12 satisfies the following equation, the flow control valve 5 moves downward away from the adjustment stopper 7.

P _p > P _c × d/D ² ... However, P _p ... Pressure in the back chamber 12 (Kg/cm ² ) P _c ... Pressure in the inflow hole 15 (Kg/cm ² ) d ... Flow rate control valve 5 Outer diameter (cm) of the spool portion 5b of the flow control valve 5 (cm) Outer diameter of the piston portion 5a of the flow control valve 5 (D>d) (cm) As the flow control valve 5 moves downward, the inflow hole 15
Since the area of the orifice 5c that opens to the bottom gradually decreases and the flow rate of the pressure oil returning from the cylinder 1a of the hydraulic jack 1 to the tank 20 decreases, the descending speed of the car 2 decreases.

This deceleration is controlled by the variable adjustment screw 9 through the throttle hole 9a.
It can be adjusted by changing the opening area of , and changing the flow rate flowing in from the throttle hole 9a. In addition, as the flow rate control valve 5 moves downward, the slow speed adjustment screw 8
The spool 8a fitted in the flow rate control valve 5 also moves downward, and the throttle hole 8d, which was closed by the spool 8a during high-speed descent, is opened, and the pressure oil passage from the throttle hole 8d to the pilot flow path 17c is communicated. Aperture hole 9
When the flow rate from the back chamber 12 to the back chamber 12 becomes equal to the flow rate from the back chamber 12 to the pilot flow path 17c through the passage 8b of the spool 8a and the throttle hole 8d, the movement of the flow rate control valve 5 is stopped. Since the area of the orifice 5c opening into the inflow hole 15 is constant, the flow rate of the pressure oil returning from the cylinder 1a to the tank 20 is constant, and the car 2 continues to descend at a constant low speed (referred to as slow speed). The slow speed can be adjusted by adjusting the position of the throttle hole 8d up or down with respect to the valve seat 6 using the slow speed adjustment screw 8, and by changing the opening point of the throttle hole 8d by the spool 8a.

When the car 2 approaches the target floor, the solenoid valve 14 is de-energized to prevent the flow of pressure oil between the pilot passages 17c and 17d, and the pressure oil flows in from the throttle holes 9a and 10a. The pressure oil has no outlet, and all of it flows into the back chamber 12 of the flow control valve 5, moving the flow control valve 5 downward, and the area of the orifice 5c that opens into the inflow hole 15 further gradually decreases, causing the hydraulic jack 1 to move downward. The flow rate returning from the cylinder 1a to the tank 20 decreases, and the car 2 decelerates.
When the flow control valve 5 is seated on the valve seat 6, the inflow hole 15
The flow of pressure oil from the to the outflow hole 16 is blocked, the ram 1b stops, and the car 2 also stops.

[Problem that the invention seeks to solve]

In the conventional descending flow rate control device for a hydraulic elevator as described above, the rated descending speed is determined by the opening area of the orifice 5c of the flow rate control valve 5 and the pressure P _c of the pressure oil. That is, the setting of the adjustment stopper 7 that determines the opening area of the orifice 5c is adjusted so that the car 2 reaches its rated lowering speed based on the pressure when the maximum load is applied to the car 2. Therefore, when the load on the car 2 is small, the flow rate of pressure oil passing through the orifice 5c decreases, and the car 2
There was a problem that the descending speed of the engine was slower than a predetermined value, resulting in a decrease in operating efficiency.

This invention is an attempt to solve the above-mentioned problems.It is possible to obtain a predetermined rated descending speed regardless of the magnitude of the load on the hydraulic jack due to the load of the passenger car, etc., and to operate even when the load is small. It is an object of the present invention to provide a flow control device for a hydraulic elevator that does not reduce efficiency.

[Means for solving problems]

The flow rate control device for a hydraulic elevator according to the present invention includes a flow rate measuring valve provided in a main pipe, and the flow rate measuring valve controlling the opening degree of a throttle valve provided in a pilot flow path that controls a flow rate control valve. The full opening degree of the flow rate control valve is controlled in accordance with the load.

[Effect]

In the flow rate control device according to the present invention, the flow rate of the pressure oil flowing through the main pipe is measured by the flow rate measuring valve, and the operation of the flow rate measuring valve is converted into the opening degree of the throttle valve provided in the pilot flow path. As a result, the opening degree of the throttle valve can be controlled in response only to the flow rate without being affected by the pressure of the pressure oil. Therefore, the full opening degree of the flow control valve can be changed in accordance with the load, and the hydraulic elevator Speed fluctuations due to load can be eliminated.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, the same reference numerals as in FIG. 5 indicate corresponding parts, 21 is a pressure chamber formed between the control valve casing 3 and the lid 4, 22 is a flow rate measuring valve, and the flow rate measuring valve 22 is used for controlling the flow rate. Tank 2 from this with valve 5
It is arranged on the 0 side and faces the main passage provided in the casing 3. 22a is a flow rate measuring valve 22
23 is a valve seat facing the flow rate measuring valve 22. Reference numeral 24 denotes a throttle valve 24a provided between the flow rate measurement valve 22 and the pilot flow path 17f.
is a throttle adjustment screw of the throttle valve 24, and this adjustment screw 24a is threadedly fitted into the lid 4 of the casing 3 and slidably fitted onto a spool 24d provided on the flow rate measuring valve 22. 24b is a throttle hole provided in the throttle adjustment screw 24a and communicates the pressure chamber 21 with the pilot passage 17f via a passage 24c provided in series in the spool 24d and the throttle adjustment screw 24a; It is a compression coil spring that presses against the valve seat 23. In addition,
The pilot passage 17f communicates with the throttle hole 11a. Further, the configuration of this embodiment other than that described above is the same as the conventional one shown in FIG.

Next, the operation of the flow rate control device of the present invention configured as above will be explained.

Similar to FIG. 5, FIG. 1 shows that the electromagnetic valves 13 and 14 are in a demagnetized state and the ram 1b of the hydraulic jack 1 is in a stopped state.

Starting and accelerating the elevator car 2 to descend is performed by energizing the solenoid valves 13 and 14. When the solenoid valves 13 and 14 are energized and opened,
The pilot channels 17b, 17c communicate with the pilot channel 17d, and the pilot channels 17b, 17c communicate with the pilot channel 17d.
Pressure oil flows through the pilot flow path 17d, the throttle hole 11a,
It flows through the pilot channel 17f, the throttle hole 24b provided in the throttle adjustment screw 24a of the throttle valve 24, the passage 24c, the pressure chamber 21, and the passage hole 22a, and flows out from the outflow hole 16 through the main pipe 19 to the tank 20.

At the same time, the pilot channel 17a is opened from the inflow hole 15.
Pressure oil also flows into the pilot channels 17b, 17c via the throttle holes 9a, 10a.

The flow rates of the pilot flow paths 17b, 17c, and 17f are adjusted to the relationship of the above formula by changing the opening areas of the throttle holes 9a, 10a, and 11a using the variable adjustment screws 9, 10, and 11, as in the conventional system described above. Adjust accordingly. In other words, the adjustment is made so that the amount of outflow from the pilot channels 17b, 17c to the outflow hole 16 side is greater than the amount of inflow from the inflow hole 15 to the pilot channels 17b, 17c.

The pressure oil having the flow rate difference between the inflow amount and the outflow amount is transferred from the back chamber 12 of the flow control valve 5 to the pilot flow path 17b.
and the passage 8 of the spool 8a of the slow speed adjustment screw 8.
b to the pilot flow path 17c via the throttle hole 8d.
It leaks out. This outflow amount is expressed by the above formula.

At this time, the flow rate control valve 5 is pushed upward by the pressure oil in the main pipe line 18 and separated from the valve seat 6, and the inflow hole 15 and the main passage 25 communicate with each other through the orifice 5c of the spool portion 5b, and the hydraulic jack 1 cylinder 1a
pressure oil flows into the main passage 25. The pressure oil flowing into the main passage 25 acts on the flow rate measuring valve 22 and becomes a force that tries to push it open upward. When this force becomes larger than the pressing force of the compression coil spring 22b acting in the direction of pushing down the flow rate measurement valve 22, the flow rate measurement valve 22 separates from the valve seat 23, and the main passage 25 and the outflow hole 16 communicate with each other. However, the pressure oil will flow into the tank 20, and the pressure oil in the cylinder 1a will flow into the tank 20.
The ram 1b descends, and the car 2 starts to descend.

As the amount of movement of the flow control valve 5 increases, the inflow hole 1
As the area of the orifice 5c opening in the cylinder 5 increases, the amount of displacement of the flow rate measuring valve 22 also increases, the flow rate of the pressure oil flowing out from the cylinder 1a to the tank 20 increases, and the car 2 accelerates downward. This acceleration is
Adjustment can be made by changing the opening area of the throttle hole 11a using the variable adjustment screw 11 and changing the flow rate of the pressure oil flowing out from the throttle hole 11a.

Note that as the flow rate measurement valve 22 is displaced, the throttle valve 24
The spool 24d is also displaced, and the aperture adjustment screw 24a
The opening area of the aperture hole 24b is reduced. When the opening area of the aperture hole 24b decreases, the aperture hole 11a
The amount Q ₁₁ of pressure oil flowing from the outlet to the outlet hole 16 side decreases, and Q ₁₁ = Q ₉ + Q ₁₀ (Q ₉ and Q ₁₀ are
When the flow rate of pressurized oil from a) reaches the point, the flow rate of _Q12 in the above equation becomes zero, there is no change in the volume of the thick oil in the back chamber 12, and the flow rate control valve 5 stops.

The flow rate of the pilot flow path during this control is Q ₉ , Q ₁₀ ,
Q ₁₁ is the pressure P _c of the inflow hole 15, the pressure P _p of the back chamber 12, and each throttle hole 9a, 10a, 11a.
It is determined by the function of the area of and 24b, P _p ≒0.5P _c
The outer diameter D of the piston part 5a and the outer diameter d of the spool part 5b of the flow control valve 5 are determined so that at a certain pressure of the inflow hole 15, the throttle holes 9a, 10a,
If 11a and 24b are set appropriately, Q ₁₁
Even if the pressure in the inflow hole 15 changes, the point where =Q ₉ +Q ₁₀ remains the same point in the throttle hole 24b, and is not affected by the pressure change in the inflow hole 15, and the flow measurement valve 2
By doing so, the car 2 is lowered at a predetermined lowering speed regardless of the magnitude of the load.

To explain this control mathematically, the pilot flow rate is
Q ₉ , Q ₁₀ , Q ₁₁ are becomes. However, A ₉ ...Area of the aperture hole 9a narrowed by the variable adjustment screw 9 (cm ² ) A ₁₀ ...Area of the aperture hole 10 squeezed by the variable adjustment screw 10
Area of a (cm ² ) A ₁₁ ... Throttle hole 11 squeezed by variable adjustment screw 11
Area of a (cm ² ) A ₂₄ ...Aperture hole 24b squeezed by spool 24d
area (cm ³ ) C: flow coefficient γ: specific gravity of fluid (Kg/cm ³ ) g: gravitational acceleration (cm/sec ² ).

Here, the conditional expression that the inflow amount Q ₉ + Q ₁₀ is equal to the outflow amount Q ₁₁ with P _p = 0.5P _c is as follows. becomes.

In the above equation, the point where the pressure term is eliminated and the inflow and outflow amounts are the same is that each throttle hole 9a, 10a, 1
This shows that it is determined only by 1a and 24b. Since A ₉ , A ₁₀ , and A ₁₁ are throttles that do not change after being adjusted to a certain pressure, the above point is determined only by the throttle of the throttle hole 24a of A ₂₄ .

Furthermore, the pressure P _p in the back chamber 12 and the pressure in the inflow hole 15
The relationship between P _c will be explained in detail.

The shape of the flow control valve 5 is determined so that the relationship between the pressure P _p in the back chamber 12 and the pressure P _c in the inflow hole 15 is P _p =0.5P _c . This means that the area on which the back chamber pressure P _p acts in the flow rate control valve 5 is twice the area on which the pressure HP _c in the inflow hole 15 acts.

If P _p = 0.5P _c , the inflow Q ₉ + Q ₁₀ is the outflow Q ₁₁
The condition for equality is expressed as an expression.

That is, regardless of the magnitude of the pressure P _c in the inflow hole 15,
When Q ₁₁ = Q ₉ + Q ₁₀ , it means that the area of the spool 24d and the throttle hole 24b is constant, and due to the structure, the opening degree of the flow rate measurement valve 22 changes only depending on the flow rate. , when the flow rate is small, the opening degree is small, and when the flow rate is high, the opening degree is also large.

For example, if the load 11 is currently acting on the car, the area of the throttle hole 24b is wide open when accelerating downward driving, so Q ₁₁
The relationship is ＞Q ₉ + Q ₁₀ . Therefore, the flow rate control valve 5 gradually opens. The hydraulic oil passes through the flow rate control valve 5 and is compressed by the compression coil spring 2 of the flow rate measurement valve 22.
Overcoming the pressing force of 2b, the flow rate measuring valve 22
to open. As the flow rate measurement valve 22 opens,
When the throttle hole 24b is gradually narrowed and reaches a certain opening degree _A24 , the relationship _Q11 = _Q9 + _Q10 is established. At this time, the hydraulic oil cannot flow out from the back chamber 12 of the flow control valve 5, and the opening degree of the flow control valve 5 becomes fixed.

It is also assumed that a load L2 different from the former is applied to the car. Similar to the former, the flow rate control valve 5 gradually opens during acceleration during descending operation, and the flow rate measurement valve 2 opens gradually.
2 is also opened. As the flow rate measurement valve 22 opens,
When the throttle hole 24b is narrowed and reaches a certain opening A ₂₄ , Q ₁₁ =Q ₉ +Q ₁₀ , the area of the throttle hole 24b narrowed by the spool 24b is related to the pressure (load). The flow rate becomes constant and the flow rate measurement valve 22
The opening degree of is also constant. The fact that the opening degree of the flow rate measurement valve 22 is the same as that at the time of the load L1 means that the flow rate passing through the flow rate measurement valve 22 is also the same as at the time of the load L1.

As a result, the high-speed traveling speed during descending operation remains constant regardless of the magnitudes of load L1 and load L2.

Therefore, when the load is changed by shaking the car while traveling at a constant high speed, assuming that the load (pressure) increases at this time, the flow rate passing through the flow rate control valve 5 will decrease. becomes larger,
The traveling speed of the car increases, and the flow rate measurement valve 2
The opening degree of 2 becomes larger. As a result, the aperture hole 24b
area becomes smaller, and the relationship Q ₁₁ <Q ₉ +Q ₁₀ is established, and the inflow amount becomes larger than the outflow amount, so the difference flows into the back chamber 12 of the flow rate control valve 5 and changes the opening degree of the flow rate control valve 5. Move in the closing direction. For this reason,
The flow rate passing through the flow rate control valve 5 is suppressed, and the running speed of the car is suppressed, returning to a constant high speed running speed. When the high-speed running speed returns to the original state, the opening degree of the flow rate measuring valve 22 also returns to its original position, resulting in a stable state. On the other hand, when the load (pressure) decreases, the operation is reversed and the high-speed running speed returns to the original state.

Further, the moving speed of the flow rate control valve 5 changes gradually as Q ₁₂ decreases, and the moving speed changes as shown in FIG. 2C with an orifice shape similar to the conventional one shown in FIG. 2A. An acceleration waveform is obtained, and the acceleration waveform at the end of acceleration is smoothly controlled. Note that FIG. 2B shows an acceleration waveform when the moving speed of the conventional flow control valve is constant.

Hereinafter, the deceleration and stopping operations are the same as those of the prior art described above.

In this embodiment, in the conventional type, the movement speed of the flow control valve is constant, so the acceleration/deceleration that determines riding comfort is determined by the area change rate of the orifice, and in order to obtain good acceleration/deceleration characteristics, the above-mentioned orifice The valve has a complicated shape and requires many types of controlled flow rates and pressures, making it expensive. However, by changing the moving speed of the flow rate control valve, good acceleration/deceleration characteristics can be obtained at low cost.

In the embodiment described above, the slow speed adjusting screw part was operated by the movement of the flow rate control valve 5 similar to the conventional one, but in the present invention, the slow speed adjusting screw part is operated by the movement of the flow rate measuring valve. It may also be made to operate by tilting it.

FIGS. 3 and 4 show another embodiment of the present invention in which the slow speed adjusting screw portion is operated by the movement of a flow rate measuring valve.

In FIGS. 3 and 4, the same reference numerals as in FIG. 1 indicate corresponding parts, and in FIG.
4a to narrow the throttle holes 8d and 24b, the shaft has cutouts 8e and 24e on the left and right ends; 27 and 28 are sealing materials having appropriate elasticity;
In FIG. 3, 29 is a lever protruding from the shaft 26;
0 is a link for transmitting the operation of the flow rate measuring valve 22 to the lever 29. 8f and 24f are holding fittings for holding the slow speed adjusting screw 8 and the aperture adjusting screw 24a at set positions, and 8g and 24g are mounting screws for tightening the holding fittings 8f and 24f. Third
The pilot channels 17g, 17h, 17i in the figure are
Pilot channels 17j, 17k, 17l in Fig. 4
are connected to each other. In addition, Figures 3 and 4
The configuration of the embodiment shown in the figure other than that described above is the same as that of the embodiment shown in FIG.

In the embodiment shown in FIGS. 3 and 4, the operation of the flow rate measuring valve 22 is converted from a linear motion to a rotational motion by a link mechanism including a link 30 and a lever 29 as main members, and is contracted and rotated toward a shaft 26. Since the opening areas of the aperture holes 8d and 24b are changed by the rotation of the shaft 26, smoother control is possible.
Furthermore, since the slow speed adjustment is determined by the opening degree of the flow rate measuring valve 22, it is not affected by the load and good operating characteristics can be obtained. The operations and effects of this embodiment other than those described above are the same as those shown in FIG.

〔Effect of the invention〕

As explained above, the present invention includes a flow rate measurement valve that measures the flow rate of the main pipe, and a throttle valve that operates in accordance with the flow rate measurement valve to control the pilot flow rate.
The opening degree of the flow control valve is changed in response to changes in the car load, and a predetermined descending speed can be obtained regardless of the car load, making it possible to provide a hydraulic elevator flow control device with high operating efficiency. There is an effect.

[Brief explanation of the drawing]

FIG. 1 is a developed sectional view showing a descending flow rate control device for a hydraulic elevator according to an embodiment of the present invention, FIG. 2A is a view showing the orifice shape of a flow rate control valve,
2B and C are diagrams showing acceleration waveforms of the conventional device and the device of the present invention, FIG. 3 is a developed sectional view showing a descending flow rate control device according to another embodiment of the present invention, and FIG. 4 is the same. A cross-sectional view of the throttle valve portion, and FIG. 5 is a developed cross-sectional view showing a conventional descending flow rate control device for a hydraulic elevator. 1... Hydraulic jack, 2... Car, 5... Flow rate control valve, 8... Slow speed adjustment screw, 9, 10,
11...Variable adjustment screw, 12...Back chamber, 13,1
4...Solenoid valve, 15...Inflow hole, 16...Outflow hole, 17...Pilot channel, 18, 19...Main pipe line, 20...Tank, 22...Flow rate measurement valve, 2
4... Throttle valve, 24a... Throttle adjustment screw, 25...
...Main passage. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A hydraulic jack to which a car is attached, a main pipe line for supplying and discharging pressure oil to the hydraulic jack, and a flow control valve disposed in the main pipe line, wherein the pressure of the main pipe line is In a flow rate control device for a hydraulic elevator that controls the flow rate of oil to control the operation of the hydraulic jack, a flow rate measuring valve whose opening degree changes depending on the flow rate of pressure oil is provided in the main pipe, and this flow rate measurement valve is provided in the main pipe. A throttle valve whose opening degree changes depending on the operation of the valve is provided in the pilot flow path of the flow control valve, and the full opening degree of the flow control valve is determined by controlling the pilot flow rate by the throttle valve. Flow control device for hydraulic elevators. 2. The flow control valve is a flow control valve for lowering a hydraulic elevator, and the degree of full opening is controlled by the balance between the inflow and outflow of the pilot flow. Flow control device for a hydraulic elevator as described. 3. The flow rate control device for a hydraulic elevator according to claim 1 or 2, wherein the flow rate control valve has a displacement speed that changes depending on a change in area of a throttle hole of the throttle valve.