JP2000327244A - Energy saving type hydraulic elevator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an energy saving type hydraulic elevator light in facility weight and low in costs in comparison with a conventional balance weight type hydraulic elevator. SOLUTION: Extension springs 12a, 12b are provided between and upper end part of a cylinder tube 54 and a lower end part of a cylinder tube 52 of a hydraulic cylinder or the neighbourhood of a fixed part of the cylinder tube 52 and a structure 77 in a hydraulic elevator constituted by providing a first pulley 71 on an upper end of a cylinder rod 54 of a differential pressure type hydraulic cylinder 51, one end of which is fixed on the structure 77 and installing an elevating car 74 on the other end of a wire rope 70 engaged with a second pulley 73 fixed on the structure 77.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy-saving hydraulic elevator, and more particularly to a lightweight and low-cost elevator.

[0002]

2. Description of the Related Art A conventional energy-saving hydraulic elevator uses a balance weight as shown in FIG.

Referring to FIG. 4, a differential pressure type hydraulic cylinder (51) is provided with a vertically mounted cylinder tube (52), a piston (53) which slides up and down in the cylinder tube, and is connected to the piston. And a cylinder tube (5).
2) Inside is a hydraulic pump (6) driven by an electric motor (61a).
It is divided into a lower piston chamber (52a) and an upper piston chamber (52b) for receiving the hydraulic oil sent from 1). In addition, (65) is a switching valve, as shown in FIG.
You can switch between stages.

A first rotatably mounted sheave (72) fixed to the upper end of the cylinder rod (54).
One end of the wire rope (70) engaged with the pulley (71) and further with a second pulley (73) rotatably attached to the structure (77) is fixed to the structure (77). The end was connected to a lifting basket (74) carrying a load (75). In the figure, (76) is a balance weight attached to the upper end of the sheave (72), and the weight of the balance (76) cancels out the weight of the lifting basket (74) and the load (75) to some extent to save energy. It is set to be able to demonstrate.

The operation of such a hydraulic elevator will be described. First, when the elevator basket (74) is to be lowered, the switching valve (65) is switched to the position D so that the upper part of the piston of the hydraulic cylinder (51) can be moved. The chamber (52b) and the lower chamber (52a) are connected between a pump and an upper chamber pipe (6).
3), pump-switching valve piping (64), switching valve (65)
And it communicates via the path of the switching valve-lower chamber piping (66). Accordingly, the pressure in the piston upper chamber (52b) and the pressure in the piston lower chamber (52a) become equal, and the lifting basket (74) suspended by the wire rope (70).
Is set to be at least larger than half the weight of the balance weight (76).
Descends. In this case, when the piston (53) rises, the hydraulic oil in the piston upper chamber (52b) is extruded and is sent into the piston lower chamber (52a) through the above-described path, so that the piston (53) is raised. Acts as hydraulic oil.

Next, when the lifting basket (74) is to be raised, the switching valve (65) is switched to the F position so that the hydraulic oil from the hydraulic pump (61) can be supplied to the pump-upper chamber piping. It is sent to the piston upper chamber (52b) via (63) and attempts to push down the piston (53). On the other hand, the piston lower chamber (52a) is provided with a pipe between the switching valve and the lower chamber (6).
6), switching valve (65), piping between switching valve and relief valve (6
7) The hydraulic oil in the piston lower chamber (52a) is pushed down by the piston (53) because it is connected to the hydraulic oil tank (62) via the relief valve (68) and the relief valve-tank pipe (69). And is discharged to the hydraulic oil tank (62). Therefore, since the cylinder rod (54) integrated with the piston (53) moving downward also descends, the lifting basket (74) suspended by the wire rope (70) rises. At this time, the balance weight is applied to the piston (5) via the cylinder rod (54).
3) works to push down and is added to the driving force of the hydraulic pump (61), so that the load on the electric motor (61a) is reduced. When the weight of the load (75) is zero or very small, the relief valve (68)
In order to prevent the piston (53) and the cylinder rod (54) from descending at an unnecessarily high speed due to the weight of 6), a certain pressure is held in the piston lower chamber (52a).

[0007]

In such a hydraulic elevator of the balance weight type, although the energy saving effect is exhibited, the equipment weight of the hydraulic elevator becomes very heavy because the weight of the balance weight is considerably large. Therefore, the structure of the structure supporting the structure has to be strengthened accordingly, and the construction cost has been increased.
Furthermore, the cost of the balance weight itself was large and costly.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem. A first pulley is provided at an upper end of a cylinder rod of a differential pressure hydraulic cylinder, and one end is fixed to a structure and the first pulley is fixed to the structure. In a hydraulic elevator having a lifting cage attached to the other end of a pulley and a wire rope engaged with a second pulley fixed to the structure, an upper end portion of a cylinder rod, a lower end portion of a cylinder tube of a hydraulic cylinder or the cylinder tube, It is an energy-saving hydraulic elevator characterized in that a tension spring is provided between the structure and the vicinity of a fixed portion thereof, and it is effective to provide a tension force adjusting device for the tension spring.

As described above, the present invention balances the total weight of the elevator basket and the load to some extent by applying a force to compress and retract the cylinder rod of the differential pressure hydraulic cylinder using the spring. The purpose of the present invention is to reduce the pressure of hydraulic oil on the differential pressure type hydraulic cylinder required for raising and lowering the lifting basket and the load. Moreover, the weight of such a tension spring is much lighter than the conventional balance weight, and the cost can be significantly reduced. Further, by providing a spring tension force adjusting device, fine adjustment of the spring force when the weight of the lifting basket and the load is balanced to some extent is possible, and the energy saving effect can be maximized.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

(Embodiment 1) As shown in FIGS. 1 and 2,
Sheave (72) fixed to upper end of cylinder rod (54)
The upper pins (10a) and (10b) are fixed to both sides of the cylinder tube (52), and the lower pins (11
a) (11b) was fixed, and tension springs (12a) (12b) were provided between the upper pin and the lower pin (that is, between 10a and 11a and between 10b and 11b). The number of springs is not limited to two, and is not limited to one or three or more. Further, in this example, the lower pin is provided at the lower portion of the cylinder tube, but may be provided at the structure side to which the cylinder tube is fixed. According to such a tension spring (12a) (12b), the sheave (7
2) is always pulled downward, so the basket (7)
4), this pulling force is applied to the piston (5).
Effectively acting on the lowering of 3), the energy saving effect of the electric motor (61a) can be obtained.

A comparison between the equipment weight in the case of using the conventional balance weight and the equipment weight in the above-described embodiment of the present invention shows that the weight of the lifting basket is 300 kg and the loading weight is 300 kg.
About 9 hydraulic balance elevators
Although the weight of 00 kg is required, the weight of the tension spring required in the present invention is about 100 kg. Therefore, according to the present invention, the weight of the equipment can be significantly reduced, and a hydraulic elevator with low cost and excellent durability can be obtained.

(Embodiment 2) As shown in FIG. 3, male threads (1) are respectively attached to lower ends of hooks (13a) (13b) engaged with lower ends of tension springs (12a) (12b).
4) was formed, and a hydraulic elevator having a structure in which this was screwed into female screw blocks (15a) (15b) provided on both lower sides of the cylinder tube (52) was manufactured. According to such a configuration, the spring force of the tension spring can be finely adjusted to a size most effective for energy saving, for example, when the set value of the loaded weight of the lifting basket is changed, and thus is useful.

[0014]

As described above, according to the present invention, a remarkable effect such as an energy-saving hydraulic elevator can be obtained at low cost, and since the equipment weight is small, the durability is excellent and the life is long. .

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention.

FIG. 2 is a side view of a main part of FIG.

FIG. 3 is an explanatory view showing another embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

 10a, 10b Upper pin 11a, 11b Lower pin 12a, 12b Tension spring 13a, 13b Hook 14 Male screw part 15a, 15b Female screw block 51 Differential pressure hydraulic cylinder 52 Cylinder tube 52a Piston lower chamber 52b Piston upper chamber 53 Piston 54 Cylinder rod 61 Hydraulic pump 61a Electric motor 62 Hydraulic oil tank 63 Pump-upper chamber piping 64 Pump-switching valve piping 65 Switching valve 66 Switching valve-lower chamber piping 67 Switching valve-relief valve piping 68 Relief valve 69 Relief valve-tank Plumbing 70 Wire rope 71 First pulley 72 Sheave 73 Second pulley 74 Elevating basket 75 Loaded material 76 Balance weight 77 Structure

Claims (2)

[Claims] A first pulley is provided at an upper end of a cylinder rod of a differential pressure type hydraulic cylinder, one end of which is fixed to a structure, and a wire rope engaged with the first pulley and a second pulley fixed to the structure. In a hydraulic elevator having a lifting cage attached to the other end, a tension spring is provided between an upper end of a cylinder rod and a lower end of a cylinder tube of a hydraulic cylinder or a vicinity of a fixed portion between the cylinder tube and a structure. Energy-saving hydraulic elevator. 2. An apparatus according to claim 1, further comprising a spring tension adjusting device.
The described energy-saving hydraulic elevator.