JP2003118950A - Hydraulic elevator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a silencer according to specifications of an elevator in order to exhibit a sufficient effect of a resonance frequency of the silencer by making it consistent with the pulse frequency of a hydraulic pump 3, without an error between the value of a theoretical calculation and the actual value, in using a silencer including a Helmholtz resonator to reduce pressure pulses generated from the hydraulic pump 3. SOLUTION: A variable aperture 23 is provided on a communicating tube 22 of a silencer 20 to make the cross-sectional area of the communicating tube 22 variable. Resonance frequencies of the silencer 20 can be adjusted by making the volume of a resonant chamber 21 variable using variable means 27 in the resonant chamber 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic elevator equipped with a device for reducing pulsation generated from a hydraulic pump.

[0002]

2. Description of the Related Art FIG. 2 is a schematic view of a general hydraulic elevator. In the figure, 1 is a hydraulic jack for raising and lowering a car 2, 3 is a hydraulic pump driven by an electric motor 4, and 5 is a hydraulic pump.
Is a main control valve, 6 is a tank, and 7 is a hydraulic pipe connecting the hydraulic jack 1, the main control valve 5, and the hydraulic pump 3. 1
Reference numeral 0 is a silencer comprising a resonance chamber 11 and a Helmholtz type resonator provided with a communication pipe 12 connecting the resonance chamber 11 to the hydraulic pipe 7.

In this hydraulic elevator, when the car 2 is raised, the hydraulic pump 3 is driven by the electric motor 4, and the hydraulic oil in the tank 6 passes through the hydraulic pipe 7, the main control valve 5 and the hydraulic pipe 7 to the hydraulic jack 1. It is pumped and the car 2 rises. Further, when the car 2 is lowered, the hydraulic pump 3 is rotated in the reverse direction so that the hydraulic oil in the hydraulic jack 1 is circulated to the tank 6 contrary to the above.

During the raising / lowering operation of the car 2, the pressure pulsation generated from the hydraulic pump 3 causes vibrations in the hydraulic pipe 7, the hydraulic jack 1, etc., which causes noise. Therefore, a silencer 10 is provided in the hydraulic pipe 7 to reduce pressure pulsation.

[0005]

The Helmholtz type resonator has no pulsation damping effect for pulsations having the same frequency as the resonance frequency determined by the volume of the resonance chamber 11 and the cross-sectional area and length of the communication tube 12. Although it is large, it has the feature that it cannot be expected to have much effect at other frequencies. Therefore, the silencer 10 is manufactured so that the resonance frequency matches the pulsation frequency of the hydraulic pump 3.

However, the pulsation frequency of the hydraulic pump used for the hydraulic elevator differs depending on the specifications of the elevator, and there are cases where there is a difference between the theoretical calculation value and the actual value.
Therefore, in order to exert a great effect by using the silencer, the silencer must be manufactured for each elevator specification. Further, there is a problem that the effect becomes small when there is an error between the theoretical calculation value and the actual value.

[0007]

SUMMARY OF THE INVENTION The present invention makes it possible to adjust the resonance frequency of a silencer by changing the cross-sectional area of a communication tube of a resonator and by changing the volume of a resonance chamber. Is.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIG. In the figure, 20 is a resonance chamber 21 and a communication pipe 22.
Is a silencer equipped with. Reference numeral 23 is a variable diaphragm provided in the communication pipe 22. The resonance chamber 21 includes the cylindrical body 24 and the first end plate 2.
5. The movable means 27 is provided with the second end plate 26. The same reference numerals as those in FIG. 2 indicate the same parts.

Since the present embodiment has the above-mentioned structure, the cross-sectional area of the communication pipe 22 can be adjusted by adjusting the variable throttle 23. Further, by adjusting the position of the second end plate 26 by the movable means 27, the volume of the resonance chamber 21 can be adjusted.

Therefore, since the resonance frequency of the silencer 20 can be adjusted, it is not necessary to manufacture the silencer according to the specifications of the elevator, and even if there is an error between the theoretical calculation value and the actual value, it can be done on site. Can be easily adjusted.

In the above embodiment, both the cross-sectional area of the communication pipe 22 and the volume of the resonance chamber 21 can be adjusted.
When the adjustment range does not need to be so wide, only one may be adjustable. Further, the silencer 20 is provided in the hydraulic pipe 7 between the hydraulic jack 1 and the main control valve 5, but may be provided in the hydraulic pipe 7 between the hydraulic pump 3 and the main control valve 5. Furthermore, although a piston-type movable means is used as a means for changing the volume of the resonance chamber 21, the present invention is not limited to this, and the cylinder is doubled and the polymerization amount of both cylinders is changed to change the volume. Other structures may be used as long as the volume can be changed, for example, by changing.

[0012]

As described above, according to the present invention,
Since the resonance frequency of the silencer consisting of the Helmholtz type resonator can be adjusted, it is not necessary to manufacture a silencer for each elevator specification, and even if there is an error between the theoretical calculation value and the actual value, it can be easily adjusted. .

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention and is a schematic diagram of a hydraulic elevator.

FIG. 2 is a schematic view of a conventional hydraulic elevator.

[Explanation of symbols]

1 hydraulic jack Two baskets 3 hydraulic pump 4 electric motor 5 Main control valve 7 Hydraulic piping 10,20 silencer 11,21 Resonance chamber 12,22 Communication pipe 23 Variable aperture 27 Movable means

Claims (2)

[Claims] 1. A hydraulic elevator comprising a silencer having a resonance chamber and a communication pipe connecting the resonance chamber to a hydraulic pipe, wherein the cross-sectional area of the communication pipe is variable. 2. A hydraulic elevator having a silencer having a resonance chamber and a communication pipe connecting the resonance chamber to a hydraulic pipe, wherein the volume of the resonance chamber is variable.