JP3301968B2 - Oil return device for hydraulic elevator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil return device of a hydraulic elevator for returning hydraulic oil from a gland of a hydraulic jack to a machine room tank.

[0002]

2. Description of the Related Art A conventional hydraulic elevator using an oil return device for a hydraulic elevator will be described with reference to FIG. In general, a hydraulic elevator has a pulley 17 rotatably provided above a plunger 15 in a hydraulic jack 7 arranged on a jack base 14 with a car 9 disposed in a hoistway 13 as shown in FIG. A rope 18 is wound around the rope 18, one end of the rope 18 is connected to a car 19, the other end of the rope 18 is connected to a jack base 14, and the plunger 15 of the hydraulic jack 7 is raised and lowered by a hydraulic device described later. This raises and lowers the car 19.

[0003] A hydraulic device for raising and lowering the car 19 is as follows.
A machine room tank 1 disposed in a machine room 12, a pump 6 that sucks hydraulic oil 2 in the machine room tank 1 through a suction pipe 3 and sends out the same through a valve and a pipe 5, and is connected to the pipe 5. An oil return device 31 having a hydraulic jack 7 that operates in response to the inflow and outflow of the hydraulic oil 2 and oil return pipes 8a and 8b for returning the hydraulic oil 2 leaked from the hydraulic jack 7 to the machine chamber tank 1 is provided. . At the inlet side of the suction pipe 3, there is provided a suction filter 10 for filtering foreign matter in the hydraulic oil 2 sucked from the machine room tank 1, and foreign matter is mixed into the machine room tank 1 for any reason. If
This foreign matter is filtered by the suction filter 10.
Also, a drain filter 1 for filtering foreign matter in the hydraulic oil 2 returned from the hydraulic jack 7 through the oil return pipes 8a and 8b.
1 is provided between the oil return pipe 8a and the machine chamber tank 1.

[0004] The hydraulic jack 7 has a plunger 15 which moves up and down in response to the inflow and outflow of the hydraulic oil 2.
5 is slidably supported by a ground portion 16 while maintaining oil tightness. When the height difference between the gland portion 16 of the hydraulic jack 7 and the machine room tank 1 is low, it is necessary to forcibly send the hydraulic oil 2 to the machine room tank 1. Will be installed. Hydraulic jack 7
The other end of the oil return pipe 8b connected to the ground portion 16 is connected to an oil return device 31, and foreign matter is removed by a filter provided in an oil return tank of the oil return device 31, and the hydraulic oil is returned from the oil return pipe 8a. 2 is returned to the machine chamber tank 1 via the drain filter 11.

In such a hydraulic elevator, the machine room 1
When the pump 6 in the cylinder 2 rotates, the hydraulic oil 2 in the machine chamber tank 1 is sucked into the suction pipe 3 through the suction filter 10, and the hydraulic oil 2 from the valve to the hydraulic jack 7 through the pump 6 and the pipe 5. Sent in. When the plunger 15 of the hydraulic jack 7 rises with this, the rope 1
The car 19 ascends in the hoistway 12 via the motor 8, and at this time, the lift speed of the car 19 can be adjusted by controlling the flow rate of the hydraulic oil 2 with a valve. On the other hand, when descending the car 19,
The hydraulic oil 2 is discharged from the hydraulic jack 7 to the machine room tank 1 via the pipe 5 and the valve, the plunger 15 is driven downward, and the car 19 is lowered via the rope 18.
At this time, the plunger 15 slides on the gland 16, and the hydraulic oil 2 adhering to the surface of the plunger 15 flows down, accumulates in the gland 16, and then returns to the oil return device via the oil return pipe 8 b. Then, the foreign matter is stored while being filtered by a filter inside the same. This is repeated with the operation of the hydraulic jack 7, and the oil return device 31
When a certain amount of hydraulic oil accumulates inside the hydraulic oil, the hydraulic oil is forcibly sent to the oil return pipe 8a while foreign substances therein are filtered by a filter, and is returned to the tank 1 via the drain filter 11.

[0006]

However, in the above-mentioned conventional oil return device for a hydraulic elevator, the hydraulic oil 2 adhering to the surface of the plunger 15 flows down and the gland portion 1
After the oil has accumulated in the oil return pipe 6, the hydraulic oil is sent to the filter of the oil return device 31 via the oil return pipe 8b, and foreign matter is filtered by this filter, and then returned to the tank 1 via the oil return pipe 8a. When the filter of the oil return device 31 is clogged, cavitation occurs in the pump section of the oil return device 31, and the operating oil of the oil return device 31 cannot be sent to the machine chamber tank 1, and in this state, Hydraulic oil 2 attached to the surface of plunger 15 is returned to oil return device 3
When the hydraulic oil is sent to the hydraulic pump 1, the hydraulic oil overflows from the ground portion 16 and flows out to the bottom in the hoistway 13. When the amount of the hydraulic oil flowing out increases, the amount of the hydraulic oil 2 in the machine chamber tank 1 decreases, and the air is sucked from the suction filter 10 to generate vibration and noise inside the pump 6 or to reduce the hydraulic pressure. The hydraulic oil 2 cannot be sufficiently fed into the jack 7 and the car 19 stops halfway, causing a failure. Therefore, the inspection operator must stop the elevator and periodically clean the filter of the oil return device 31 in the hoistway 13. However, depending on the site, the amount of foreign matters flowing out is large and the oil return is performed earlier than the cleaning cycle. Device 31
Filter is clogged, and in this state, if the inflow of hydraulic oil continues, the hydraulic oil overflows and flows out into the hoistway 13, and when the amount of outflow reaches a predetermined amount, the car 19 moves on the middle floor. It may stop.

An object of the present invention is to provide an oil return device for a hydraulic elevator, which facilitates inspection of a filter which leads to a car stoppage accident.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a hydraulic jack having a plunger which lifts and lowers hydraulic oil from a machine chamber tank storing hydraulic oil. In an oil return device of a hydraulic elevator, an oil return device having an oil return tank is connected through a return pipe, and the hydraulic oil is returned to the machine chamber tank through another oil return pipe connected to the oil return device. On the oil return pipe side of the oil return tank, a filter for filtering foreign matter in the hydraulic oil from the gland portion, and another filter located downstream of the oil return from the filter are provided. The filter provided on the oil return pipe side has a mesh smaller than that of the other filter located downstream of the oil return pipe.

According to the oil return device for a hydraulic elevator according to the present invention, as described above, the mesh of the filter for filtering foreign matter provided on the upstream side of the oil return of the oil return tank is roughened by the mesh of the other filters on the downstream side of the oil return. Therefore, if the filter provided on the upstream side of the oil return is inspected, the state of other filters provided on the downstream side can be predicted. Only the filter needs to be inspected frequently, and the inspection interval for clogging of the filter unit such as the suction filter can be extended to easily perform the inspection of the filter leading to a car stop accident.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing a main part of a hydraulic elevator using an oil return device for an elevator according to an embodiment of the present invention. A hydraulic device for raising and lowering a car draws a machine room tank 1 disposed in a machine room, and a hydraulic oil 2 in the machine room tank 1 through a suction pipe 3 and sends it out through a valve 4 and a pipe 5. A pump 6, a hydraulic jack 7 connected to the pipe 5 and operated according to the inflow and outflow of the hydraulic oil 2, oil return pipes 8 a and 8 b for returning the hydraulic oil 2 leaked from the hydraulic jack 7 to the machine chamber tank 1, An oil return device 31 having At the inlet side of the suction pipe 3, there is provided a suction filter 10 for filtering foreign matter in the hydraulic oil 2 sucked from the machine room tank 1, and foreign matter is mixed into the machine room tank 1 for any reason. In this case, the foreign matter is filtered by the suction filter 10. A drain filter 11 for filtering foreign matter in the hydraulic oil 2 returned from the hydraulic jack 7 via the oil return pipes 8a and 8b is provided between the oil return pipe 8a and the machine chamber tank 1.

The hydraulic jack 7 has a plunger 15 which moves up and down in response to the inflow and outflow of the hydraulic oil 2.
5 is slidably supported by a ground portion 16 while maintaining oil tightness. The ground portion 16 of the hydraulic jack 7 has a groove 16a and a guide path 16b for guiding the hydraulic oil 2 accumulated in the groove 16a to an oil return pipe 8b. The other end of the oil return pipe 8b is connected to an oil return device 31. Is connected to the oil return tank section 33 via the filter section 32b. The pump 34 of the oil return device 31 includes a pipe 34a that guides the working oil 2 accumulated in the oil return tank 33 into the pump 34, and a pipe 34a provided at the tip of the pipe 34a to prevent foreign matter from entering the pump 34. The hydraulic oil 2 sucked up by the pump 34 is returned to the machine chamber tank 1 via the oil return pipe 8a and the drain filter 11. When the hydraulic oil 2 accumulates in the oil return tank 33 and the detection sensor 35a that detects the upper surface limit of the hydraulic oil 2 is activated, the pump 34 is operated by the output of the detection sensor 35a to operate the oil return tank 33. The oil 2 is sent into the tank 1, and when the detection sensor 35 b provided in the oil return tank 33 and detecting the lower limit is activated, the hydraulic oil from the oil return tank 33 to the machine chamber tank 1 is actuated. 2
Is terminated.

In such a hydraulic elevator, when the pump 6 in the machine room rotates, the hydraulic oil 2 in the machine room tank 1
Is sucked into the suction pipe 3 through the suction filter 10 and is sent from the valve 4 to the hydraulic jack 7 through the pump 6 and the pipe 5. The hydraulic jack 7
When the plunger 15 is lifted, a car (not shown) rises in the hoistway. On the other hand, when descending the car, the hydraulic oil 2 is discharged from the hydraulic jack 7 to the machine room tank 1 via the pipe 5 and the valve 4, and the plunger 15 is driven downward. At this time, the plunger 15
Slides on the ground portion 16 and the plunger 1
After the hydraulic oil 2 adhering to the surface of the oil tank 5 flows down and accumulates in the groove 16a of the gland portion 16, the hydraulic oil 2 flows from the groove 16a through the oil return pipe 8b to the filter container 32a of the oil return device 31. The foreign matter is collected in the oil return tank 33 while being filtered by the filter 32b therein. This is repeated with the operation of the hydraulic jack 7, and when the hydraulic oil 2 is fed into the oil return tank portion 33 and the upper surface limit is detected by the detection sensor 35a, the pump portion 34 operates to operate the oil return tank portion 33. Hydraulic oil 2
While passing through the oil return pipe 8a while the foreign matter therein is being filtered by the filter portion 34b, the foreign matter is returned to the machine room tank 1 via the drain filter 11.

Next, the main part of the oil return device 31 will be described with reference to the enlarged sectional view shown in FIG. A cylindrical inner filter 22 is provided in the cylindrical filter container portion 32a.
And a filter portion 32b composed of the outer filter 23 and the upper end thereof is sealed by a removable lid 24. The lid 24 has a receiving port 29 for receiving the hydraulic oil 2 returned through the return pipe 8b, and is fixed to the filter container 32a by the fixture 30 while being attached to the upper end of the filter container 32a. ing. The inner filter 22 having a small diameter is a mesh portion 26 whose side surface is formed of a mesh member, a flange portion 27 is formed in a circumferential direction at an open upper end, and a through hole 28 is formed at an upper portion of the mesh portion 26. ing. Similarly, the outer filter 23 is a mesh portion 26a whose side surface is formed of a mesh member,
A flange 27a is formed in the circumferential direction at the upper end that is opened.
Further, a through hole 28a is formed in an upper portion of the mesh portion 26a. The mesh roughness of the mesh portions 26 and 26a of the inner and outer filters 22 and 23 is equal to or less than the mesh roughness of the filter 34a, the suction filter 10 and the drain filter 11 shown in FIG. Has set it more finely.

Now, when the hydraulic oil 2 containing foreign matter is sent from the gland portion 16 of FIG. 1 to the oil return device 31 via the oil return pipe 8b, the filter container portion is opened through the upper receiving port 29 shown in FIG. Foreign matter that has entered the hydraulic oil 2 when flowing into the inside 32 a and passing through the mesh portion 26 of the inner filter 22 is filtered. Next, the mesh part 26 of the outer filter 23
a, the foreign matter mixed in the hydraulic oil 2 is also filtered, and the filtered hydraulic oil 2 accumulates at the bottom of the filter container 32a and the outlet 2 of the filter container 32a.
The oil is discharged from 1a, and is guided into the oil return tank 33 from the receiving port 33a through the connection pipe 25.

As the return device 31 operates as described above, foreign matter gradually adheres to the inside of the mesh portion 26 of the inner filter 22, and when the mesh portion 26 is clogged, the hydraulic oil 2 is placed inside the mesh portion 26. Gradually accumulates.
Next, when the liquid level of the hydraulic oil 2 reaches the upper portion of the mesh portion 26, the through hole 2 formed in the upper portion of the mesh portion 26 is formed.
8 and flows into the outside of the mesh part 26, that is, the inside of the mesh part 26a of the outer filter 23.
Similarly, when foreign matter adheres to the inside of the mesh portion 26a of the outer filter 23 and the mesh portion 26a is clogged, when the liquid level of the hydraulic oil 2 reaches the upper portion of the mesh portion 26a, the upper portion of the mesh portion 26a Through hole 28 formed in
a, and is discharged from the outlet 21 at the bottom of the filter container 32a.

The hydraulic oil 2 containing foreign matter as described above is first guided to the filter portion 32b of the return device 31, and is removed by the mesh portions 26, 26a of the filter portion 32b. Moreover, the mesh portions 26, 26a of the inner and outer filters 22, 23 constituting the filter portion 32b.
The hydraulic oil 2 stored in the oil return tank 33 is supplied to the pump 34 because the size of the filter is not more than the roughness of the filter located downstream of the oil return such as the filter 34b, the drain filter 11 and the suction filter 10. 34 filters 3
Since the clogged foreign matter has already been removed in 4b, it is not necessary to inspect the filter 34b at least before the filter 32b. Therefore, if the clogging status of the filter unit 32b is monitored, the clogging status of another filter is known, and the filter unit 32b may be constantly monitored.

In particular, since the inner and outer filters 22 and 23 constituting the filter portion 32b are cylindrical, and the through holes 28 and 28a are formed in the upper portions thereof, the hydraulic oil flows from the through holes 28 and 28a. The mesh portion 2 depends on whether it is flowing in, and whether the hydraulic oil 2 is accumulated in the inner and outer filters 22 and 23.
Since it is possible to determine whether or not clogging is performed at 6, 26a, monitoring is easy. In this way, the filter 34b and the suction filter 10, which are arranged in the tank 33 and cannot be easily inspected, need not be inspected, and the cleaning time thereof can be reduced.

If the size of the filter portion 34b is smaller than the size of the filter portion 32b, the filter portion 34b is clogged first, causing cavitation in the pump 34 and an elevator stop accident. There is danger. The filter unit 32b and the filter unit 34
If the eyes of the drain filter 11 are finer than the eyes of b, the drain filter 11 will be clogged first, causing the same failure as described above. Similarly, when the eyes of the suction filter 10 are finer than the eyes of the filter parts 32b and 34b and the drain filter 11,
Firstly, the suction filter 10 is clogged, and the hydraulic oil 2 cannot be sufficiently supplied to the pump 6 to generate vibration or noise, or the hydraulic oil 2 cannot be sufficiently supplied to the hydraulic jack 7 and the car is stopped halfway. Failures such as stoppage may occur. However, as described above, the meshes of the mesh portions 26 and 26a of the inner and outer filters 22 and 23 are located on the oil return downstream side of the filter 34a, the suction filter 10, the drain filter 11, and the like shown in FIG. Since the mesh size is set to be equal to or smaller than the mesh size of the other filters, that is, the same mesh size or finer, the above-described failure can be prevented by a simple inspection of the filter unit 32b.

In the above-described embodiment, the oil return pipe 8
Although the drain filter 11 is provided on the machine chamber tank 1 side, which is the oil return downstream side of a, the drain filter 11 can be omitted.

[0020]

As described above, in the oil return device for a hydraulic elevator according to the present invention, the filter provided before the hydraulic oil enters the oil return device from the gland of the hydraulic jack is disposed downstream of the oil return device. Since the filter provided was less than the coarseness of the filter provided, the clogging status of the filter provided before entering the oil return device can be monitored. Inspection can be omitted, and the inspection of the filter leading to the accident of stopping the car can be facilitated.

[Brief description of the drawings]

FIG. 1 is a front view showing an oil return device for a hydraulic elevator according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the oil return device of the hydraulic elevator shown in FIG.

FIG. 3 is a cross-sectional view illustrating a general hydraulic elevator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Machine chamber tank 2 Hydraulic oil 3 Suction pipe 5 Pipe 6 Pump 8a, 8b Return pipe 10 Suction filter 11 Drain filter 15 Plunger 16 Ground part 26, 26a Mesh part 28, 28a Through hole 31 Oil return device 32b, 34b Filter part 33 Oil return tank part 34 Pump part 34a Pump piping

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Katsushi Kawamo 1-6-6 Kandanishikicho, Chiyoda-ku, Tokyo Inside Hitachi Building Systems Co., Ltd. (56) References JP-A-10-109835 (JP, A) JP-A-10 JP-A-120335 (JP, A) JP-A-9-77421 (JP, A) JP-A-58-210810 (JP, A) JP-A-2-34578 (JP, U) JP-A-62-96106 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B66B 9/00-9/193

Claims (3)

(57) [Claims] An oil return device having an oil return tank is connected via an oil return pipe to a gland of a hydraulic jack having a plunger for sucking and discharging hydraulic oil from a machine chamber tank storing hydraulic oil. An oil return device of a hydraulic elevator that returns the working oil to the machine chamber tank through another oil return pipe connected to the oil return device, wherein the oil return tank is provided with the oil return pipe side from the gland portion. A filter for filtering foreign matter in the hydraulic oil and another filter located on the oil return downstream side of the filter are provided, and the coarseness of the filter provided on the oil return pipe side of the oil return tank, An oil return device for a hydraulic elevator, characterized in that the size of the other filter located downstream of the oil return is less than the mesh size. 2. The filter according to claim 1, wherein another filter is provided on the other oil return pipe side in the oil return tank, and the filter provided on the oil return pipe side of the oil return tank is: An oil return device for a hydraulic elevator, wherein the size of the other filter provided in the oil return tank is set to be equal to or less than the coarseness of the filter. 3. The filter according to claim 1, wherein the filter provided on the oil return pipe side of the oil return tank comprises:
A filter container portion that connects between the oil return pipe and the oil return tank, a cylindrical inner filter and an outer filter that are disposed in the filter container and have a side portion having a mesh portion; An oil return device for a hydraulic elevator, wherein a through hole through which the hydraulic oil flows when the mesh portion is clogged is formed above the mesh portion of the outer filter.