JPH0471835B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to the structure of a power unit for a hydraulic elevator.

[Technical background of the invention and its problems]

Hydraulic elevators have a jack directly below the car, and there are two types: a direct type that raises and lowers the car directly, and an indirect type that uses ropes, mesh wheels, etc.

FIG. 1 shows a schematic diagram of the above-mentioned direct hydraulic elevator. Machine room 2 adjacent to hoistway 1
Inside is a power unit 3 which is the drive source for the hydraulic elevator. Pressure oil generated by the power unit 3 is sent to the jack 5 through a pipe 4, and as the plunger 6 rises, the car 7 at the upper end of the plunger rises in the hoistway 1. In addition, the guide device 8
This is a guide when the cage 7 moves up and down along the guide rail 9. On the other hand, regarding the descent of car 7, car 7
Due to its own weight, the liquid in the cylinder 10 passes through the pipe 4 and flows back to the tank 11 of the power unit 3, causing the car 7 to descend.

Next, the structure of the power unit 3 described above and its function will be described. As shown in FIG. 1, the power unit 3 includes a tank 11, a base 12, and an electric motor 1.
3, a hydraulic pump 14, a flow control valve 15, etc. That is, the liquid in the tank 11 is discharged by the hydraulic pump 14 driven by the electric motor 13, and the discharged pressure liquid is passed through the flow control valve 1.
5 to control the flow rate and cylinder 1
Send pressure liquid into 0. This causes the plunger 6 to rise, and the car 7 to rise accordingly. On the other hand, when descending, the liquid in the cylinder 10 flows through the pipe 4 due to the weight of the car 7, and the amount of liquid returned to the tank 11 is controlled by the flow rate control valve 15 as the car 7 descends according to a predetermined running pattern.

Now, in recent years, due to the effective use of space and housing conditions, the living room 16 is often placed near the machine room 2 or the hoistway 1. Noise problems may occur due to pump pulsations propagating through the liquid to the living room 16 and the car 7 arranged in this manner and pressure pulsations generated by the flow rate control valve. As a countermeasure against these problems, conventional silencers 17 are placed in the piping between the flow control valve 15 and the cylinder 10 to prevent pressure pulsations generated from both the flow control valve 15 and the hydraulic pump 14 from propagating to the cylinder 10 side. It is said that However, the silencer 1 with this arrangement
According to 7, relatively high cycle (more than about 500Hz)
This is sufficient to reduce the pressure pulsation of a flow control valve that generates pressure pulsations of
In many cases, it is insufficient to reduce the pressure pulsation generated by a pump with a large amplitude (around Hz), and there is a problem that noise problems in the living room 16 and the car 7 are likely to occur.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned problems, and in particular reduces the noise caused by the pressure pulsations generated by the hydraulic pump by devising the conventional arrangement of equipment. The objective is to reduce the influence of noise on the living room and the car.

[Summary of the invention]

The present invention provides a hydraulic elevator in which a silencer is interposed between a hydraulic pump that generates hydraulic pressure and a flow rate control valve, and the length of the piping is set to an integral multiple (including 0) of a half wavelength of pressure pulsation. From a practical standpoint, the length of the piping is set extremely short to obtain a pulsation reduction effect using a silencer.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.
In the present invention, as shown in FIG. 2, a silencer 17 is provided between the internal hydraulic pump 14 and the flow control valve 15 of the power unit 3, and a short piping length is used to connect the silencer 17 between them. According to experiments based on this configuration, the pulsation reduction effect of the silencer 17 is greatly influenced by the piping length from the discharge port of the pump 14 to the silencer 17, and the piping length is an integral multiple of the half wavelength of the pressure pulsation (from 0 to (including) is very effective, and conversely, the effect is significantly reduced when the length is an odd multiple of 1/4 wavelength. Practically speaking, great effects can be obtained by keeping the length of the piping within an integer of about ±8% of a half wavelength. In the case of oil used as a normal liquid, the frequency of the pump's pressure pulsation is
If the frequency is about 100Hz, the wavelength will be about 10m. Therefore, the piping length from the hydraulic pump discharge port to the silencer 17 is good if it is 0m ⁺⁸ %, 5m ^±8 %, or 10m ^±8 %, and bad if it is 2.5m or 7.5m. Normally, the machine room 2 is small, and it is difficult to make this piping length 5 m or 10 m. Further, when the flow rate control valve 15 is disposed between the hydraulic pump 14 and the silencer 17 as in the conventional case, it is difficult to make the above-mentioned piping length close to zero because the flow rate control valve is disposed.

The present invention attempts to shorten the length of this piping by disposing a silencer 17 between the hydraulic pump 14 and the flow control valve 15. As a result, the piping length l between the pump discharge port and the silencer 17
can be made much shorter than before, about 100mm. Practically, as mentioned above, about 8% is acceptable, so if it is 40 mm or less, the effect can be sufficiently obtained.

On the other hand, by arranging the silencer in this manner, the effect against the pressure pulsations generated by the hydraulic pump 14 is sufficient, but there is a concern that the effect against the pressure pulsations generated by the flow control valve 15 will be reduced. However, in normal usage conditions, the high-cycle pulsations generated by the flow control valve 15 are easily attenuated due to their high cycles, and there are few cases in which they propagate to the living room 16 or the car 7 and cause noise problems.

Moreover, as shown in FIG. 3, by providing the silencer 17a at a position where it has been used conventionally, even better effects can be achieved.

In the above description, an example is given in which the flow rate control valve 15 is arranged at the upper part of the tank 11.
This is because a pipe passes through the inside of the tank 11, so a silencer 17 is interposed therein.

As shown in FIG. 4, even when the flow control valve 15 is disposed at the bottom of the tank, the same effect can be obtained by providing a silencer 17 between the hydraulic pump 14 and the flow control valve 15.

〔Effect of the invention〕

As explained above, according to the present invention, since the silencer can be placed near the discharge port of the hydraulic pump as a noise suppression effect, the effect of the silencer is much greater than that of the conventional one, and the pressure pulsation of the hydraulic pump is reduced. Since the noise is less likely to propagate to the living room 16 and the car 7, the amount of noise generated is extremely reduced. Also. Flow control valve 1
5 is placed above the tank, the power unit can be made more compact by providing the silencer 7 at the tank penetration part of the piping, and since the power unit includes the silencer, the space actor in the machine room is improved, and it is extremely efficient in terms of output. You will get many benefits such as being advantageous.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of the structure of a hydraulic elevator, FIGS. 2 and 3 are side views of a power unit according to the present invention, and FIG. 4 is a side view of a power unit according to another embodiment of the present invention. 1... Hoistway, 3... Power unit, 4...
Piping, 5... Jacket, 6... Plunger, 7...
...basket, 11...tank, 14...hydraulic pump,
15...Flow control valve, 17, 17a...Silencer.

Claims (1)

[Scope of Claims] 1. A jack is provided in the hoistway, a plunger is engaged with the jack, a car is attached to the top of the jack, and a hydraulic pump and a flow control valve are used to cause hydraulic pressure to enter and exit the jack and the plunger. A hydraulic elevator for raising and lowering a car, characterized in that a silencer is interposed between the hydraulic pump and the flow control valve. 2. The hydraulic elevator according to claim 1, wherein the length of the piping between the discharge port of the hydraulic pump and the silencer inlet is 400 mm or less. 3. Claim 1, characterized in that the hydraulic pump is provided at the bottom of the tank, the flow control valve is provided at the top of the tank, and a silencer is arranged at the tank penetration part of the piping between the hydraulic pump and the flow control valve. hydraulic elevator.