JP3352010B2 - Check valve for correcting stroke of 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 a check valve for correcting a stroke of a hydraulic elevator, and more particularly, to simplifying the structure of a check valve for automatically correcting the stroke of a hydraulic elevator to enhance machining accuracy. The present invention relates to a technique for stabilizing the operation.

[0002]

2. Description of the Related Art Hitherto, as a means for correcting a deviation of a stop position of a hydraulic elevator, one having a structure shown in FIG. 3 has been proposed. Hereinafter, the means will be described in detail. A first piston 2 is provided in a vertically movable cylinder tube 1 so as to be movable up and down. A small-diameter tube 3 is extended from the first piston 2 so that the small-diameter tube 3 can be freely protruded from the upper end of the cylinder tube 1. The second piston 4 is protruded and provided in the small-diameter tube 3 so as to be movable up and down.
The piston rod 8 extends upward, the piston rod 8 protrudes from the upper end of the small-diameter tube 3 so as to be freely protruded, the through-hole 5 penetrates through the second piston 4, and the small-diameter tube 3 is inserted into and out of the small-diameter tube 3. A communication hole 6 is formed to communicate the hydraulic fluid, a port 7 for introducing hydraulic oil for raising the first piston 2 is formed below the first piston 2, and a cylinder tube 1 and a small-diameter tube 3 are formed above the first piston 2. And the hydraulic elevator in which the pressure oil 9 is sealed between the small-diameter tube 3 and the piston rod 8,
The pressure oil 9 sealed above the first piston 2 leaks to the outside as shown by an arrow A, or the amount of the pressure oil 9 leaked to the inside as shown by an arrow B decreases. is there.

When the amount of the pressure oil 9 decreases, the distance L ₂ between the first piston 2 and the second piston 4 cannot be secured, and when the distance L ₂ becomes zero, The second piston 4 collides with the first piston 2 to generate a shock. In the case of the telescopic configuration, the distance L ₁ + the distance L ₂ between the first piston 2 and the bottom is constant (constant; L ₁ increases as L ₂ decreases), and the distance L ₁ + distance L ₂ > If L ₃ (the amount of allowance in the upper part of the rising stroke), the P surface of the first piston 2 collides with the R surface before S ₂ becomes zero, and a shock occurs. Then, in order to operate without causing a shock, it is only necessary to set L ₁ + L ₂ <L ₃ and to operate such that L ₂ > 0.

By the way, even if the pressure oil 9 leaks, L ₂ > 0
The first piston 2 is provided with a check valve for replenishing the working oil of a certain pressure or more from the bottom side of the cylinder tube 1 to the rod side from the bottom side of the cylinder tube 1, and the leak of the pressure oil 9 is performed through the check valve. It is also considered to supplement the minutes. That is, by manually lowering the elevator car 11 further below the lowermost reference position, a negative pressure is generated on the side of the pressurized oil 9 sealed above the first piston 2 and the state is checked in the negative pressure state. The hydraulic oil is supplied from the valve to the pressure oil 9 side. In order to lower the elevator car 11 further below the lowermost reference position, manual operation is performed. The operation is suspended and the workability is poor, and the leaks into and out of the hydraulic elevator differ individually, the stroke correction cycle is not constant, the maintenance time is not constant, and maintenance is troublesome. And so on.

[0005]

Therefore, a check valve 10 for replenishing the first piston 2 with pressurized oil is provided, as shown in FIG. There is a stroke correction method for a hydraulic elevator in which hydraulic oil is replenished by a simple method of lowering using an operation system below a lower reference position, thereby easily correcting the stroke of the hydraulic elevator.

According to this method, the elevator car 11
Is further lowered from the lowermost reference position using the operation system, and a negative pressure is generated on the side of the pressurized oil 9 sealed according to the amount of the lowering, and the hydraulic oil 9 Side, the hydraulic fluid is replenished in the elevator operation system, the stroke can be corrected, the maintenance of the elevator can be performed more easily than that performed manually, and the operation of the elevator can be stopped. You can do that too.

However, as shown in FIG. 4 (b), the check valve 10 in such a method has the first piston 2
A valve hole 17 is formed in the valve body 15 and the valve body 15 is held through the sleeve 22. The lower valve shaft 16a formed in a series on the valve body 15 is thinner than the upper valve shaft 16b and the valve hole 17. In the sleeve 22, it is necessary to machine the small-diameter valve hole 17 and the large-diameter guide hole 23 so that the centers thereof are aligned, and the structure of the check valve 10 becomes complicated, and high machining accuracy is required. If the center of the hole 17 does not coincide with the center of the guide hole 23, there is a problem that it becomes difficult to stabilize the characteristics.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and a structure of a check valve for automatically correcting a stroke of a hydraulic elevator is simplified, and the operation of the hydraulic elevator can be stabilized. It is an object to provide a check valve for correcting a stroke.

[0009]

According to the first aspect of the present invention, a first piston 2 is provided so as to be able to move up and down in a cylinder tube 1 installed in a vertical direction, and a small-diameter tube 3 is extended from the first piston 2. A small-diameter tube 3 is protruded from the upper end of the cylinder tube 1 so as to be able to change the projection amount, and a second piston 4 is provided in the small-diameter tube 3 so as to be able to move up and down.
A piston rod 8 extends upward from the piston 4, the piston rod 8 protrudes from the upper end of the small-diameter tube 3 so as to be freely protruded, a through hole 5 penetrates through the second piston 4, and the small-diameter tube 3 passes through the small-diameter tube 3. A communication hole 6 communicating the inside and outside of the cylinder tube is formed, and a first hole is formed in a lower portion of the cylinder tube 1.
A port 7 for introducing hydraulic oil for raising the piston 2 is formed, and a pressure oil 9 is provided between the cylinder tube 1 and the small-diameter tube 3 and between the small-diameter tube 3 and the piston rod 8 above the first piston 2. An elevator car connected to an upper end of a piston rod 8 in a hydraulic elevator provided with a check valve 10 for refilling the first piston 2 with hydraulic oil having a predetermined pressure or more from a bottom side of the cylinder tube 1 to a rod side of the cylinder tube 1. 11 is forcibly lowered using the operation system further below the lowermost reference position to generate a negative pressure on the side of the pressure oil 9 sealed above the first piston 2, and in this negative pressure state The check valve 10 for replenishing hydraulic oil to the hydraulic oil 9 side,
The first piston 2 extending from the valve body 15 of the check valve 10 in the moving direction of the valve body 15 to form the valve hole 17
A guide hole 18 for slidably holding the valve shaft 16 is formed to have the same diameter as the valve hole 17, and one end of the guide hole 18 is formed inside the valve shaft 16.
Bets 7 through hole 19 to form a through hole 19 in communication
A communication hole 20 communicating with the other end side and communicating with the outside of the valve shaft 16 in the radial direction of the valve shaft 16 is formed on the valve shaft 16 side from the valve body 15, and the valve body 15 is closed in a direction to close the valve hole 17. It is characterized by being urged by a spring 21.

(Function) In the first aspect, the hydraulic oil can be replenished through the through hole 19 and the communication hole 20 inside the valve shaft 16. In this case, the valve hole 17 and the guide hole 18 have the same diameter. As a result, the configuration of the check valve 10 can be simplified, and the operation of the check valve 10 can be easily stabilized without requiring high processing accuracy.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1A is a schematic plan view of the check valve 10, FIG. 1B is a sectional view, FIG. 2A is an overall sectional view, FIG. 2B is a schematic sectional view of the entire elevator, and FIG. FIG.

As shown in FIG. 2, a first piston 2 is provided in a cylinder tube 1 installed in a vertical direction so as to be movable up and down. A small-diameter tube 3 extends from the first piston 2. Small diameter tube 3 is cylinder tube 1
Projecting from the upper end of the housing so that the amount of projection can be changed. A second piston 4 is provided in the small-diameter tube 3 so as to be able to move up and down. A piston rod 8 extends upward from the second piston 4. A piston rod 8 protrudes from the upper end of the small-diameter tube 3 so as to be able to change the protruding amount. A through hole 5 is penetrated through the second piston 4. The small-diameter tube 3 is provided with a communication hole 6 for communicating the inside and the outside of the small-diameter tube 3. A port 7 for introducing hydraulic oil for raising the first piston 2 is formed below the cylinder tube 1. A pressure oil 9 is sealed between the cylinder tube 1 and the small-diameter tube 3 above the first piston 2 and between the small-diameter tube 3 and the piston rod 8. Furthermore, the first
The piston 2 is provided with a check valve 10 for replenishing hydraulic oil of a certain pressure or more from the bottom side of the cylinder tube 1 to the rod side of the cylinder tube 1.

In the above-described telescopic type hydraulic elevator (hydraulic jack), when the enclosed pressure oil 9 leaks inside and outside, the amount of the enclosed pressure oil 9 decreases. and, Thus the first piston 2 distance L ₂ is can not be secured between the second piston 4, the elevator car 11 when lowering the reference position of the lowermost, second piston 4 is in the first piston 2 The collision causes a shock, and in order to prevent the occurrence of the shock, the amount of the leaked pressure oil 9 is replenished. The replenishment is performed as follows.

That is, the elevator car 11 connected to the upper end of the piston rod 8 is forcibly lowered by using the operation system further below the lowermost reference position. Solenoid valve (not shown) provided in
To switch the oil from the port 7 to tank (not shown)
And the amount of descending of the elevator car 11 is determined by the timer until the detected position 11a such as the cam of the elevator car 11 contacts the position detection switch 12 or the return operation time of the solenoid valve. The load of the elevator car 11 is not applied to the first piston 2 because the set amount or the buffer 13 is hit, and the chamber 14 of the port 7 is
Until zero pressure is detected. That is, port 7
The pressure on the side of the chamber 14 is kept higher than the pressure of the sealed pressure oil 9. In this manner, a negative pressure is generated on the side of the pressure oil 9 sealed above the first piston 2, and the hydraulic oil is replenished from the check valve 10 to the side of the pressure oil 9 in the negative pressure state. This replenishment is performed until the pressure in the chamber 14 on the port 7 side becomes equal to the pressure on the pressure oil 9 side. Completion of the replenishment of the pressure oil 9 can be easily determined based on the detection result of the pressure of the chamber 14 and the pressure of the pressure oil 9. After such replenishment to the hydraulic fluid 9 side is performed, since L ₂ and back to the reference position of the lowermost (or the reference position of the other floors) based on a control program elevator car 11 is secured is there. And the upper margin stroke L ₃ >
By setting L ₁ + L ₂ = constant (constant), a shock at the upper floor can be avoided. In the case of a three-stage telescopic hydraulic elevator (hydraulic jack), L ₃ > constant (constant). In the figure, S ₁ indicates the stroke of the first piston 2, and S ₂ indicates the stroke of the second piston 4.

In order to automatically lower the elevator car 11 further below the lowermost reference position, a signal when the elevator car 11 is located at the lowermost reference position is used. This is performed by using a signal when the car 11 is located at a reference position other than the lowest stage, for example, when the elevator car 11 has been stopped on the second floor for a long time, and the stroke correction is performed based on the detection result. In addition, a timer can be incorporated in the control circuit, and the stroke can be corrected based on the set time of the timer. In this way, when performing stroke correction after a long stop at a specific floor, or when setting the timer to a time that is not used by people, the stroke correction can be performed without disturbing the user. You can do it.

The check valve 10 is configured as follows. As shown in FIG. 1, the valve body 15 of the check valve 10
The valve shaft 16 extends in the moving direction of the valve body 15. First
A first sleeve 23 is fitted into a hole formed in the piston 2, and a second sleeve 22 having a valve hole 17 is fitted into the first sleeve 23. First and second sleeves 2
A holding member 24 is placed on the holding members 3 and 22.

The second sleeve 2 forming the valve hole 17
A guide hole 18 for slidably holding the valve shaft 16 is formed at the same diameter as the valve hole 17. One end inside the valve shaft 16
A communication hole 20 which communicates with the other end of the communication hole 19 and which communicates with the outside of the valve shaft 16 in the radial direction of the valve shaft 16 is formed in the valve shaft 1 from the valve body 15.
It is formed on the 6 side. The communication hole 20 is opened in a recess 25 formed in the valve shaft 16. The holding member 24 has the concave portion 2
6, the valve body 15 is housed. Holding member 24
A spring 21 is interposed between the valve body 15 and the valve body 15 to urge the valve body 15 in a direction to close the valve hole 17. A through hole 27 is formed in the holding member 24 so that hydraulic oil is supplied to the pressure oil 9 side.

As described above, the valve hole 17 and the guide hole 18 have the same diameter, so that the structure of the check valve 10 can be simplified, and the operation of the check valve 10 can be easily stabilized without requiring high machining accuracy. Things.

[0019]

According to the first aspect of the present invention, the elevator car connected to the upper end of the piston rod is forcibly lowered by using the operation system further below the lowermost reference position,
A negative pressure is generated on the pressure oil side enclosed above the first piston, and the hydraulic oil is replenished from the check valve to the pressure oil side in such a negative pressure state, so that the stroke of the hydraulic elevator can be corrected, and maintenance of the elevator can be performed. Can be easily performed as compared with the manual operation, and it is not necessary to stop the operation of the elevator. A guide hole for slidably holding the valve shaft is formed in the formed first piston to have the same diameter as the valve hole, and one end is formed inside the valve shaft.
Other hole to form a through hole which side is communicated with the port
Since the communication hole communicating with the end side and communicating with the outside of the valve shaft in the radial direction of the valve shaft is formed on the valve shaft side from the valve body, the hydraulic oil passes through the communication hole inside the valve shaft and the communication hole. In this case, the valve hole and the guide hole have the same diameter, so that the structure of the check valve can be simplified, and the operation of the check valve can be easily stabilized without requiring high processing accuracy. There is.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a check valve of the present invention,
(A) is a plan view and (b) is a cross-sectional view.

2A is a cross-sectional view, FIG. 2B is a schematic cross-sectional view of the entire elevator, and FIG. 2C is a schematic explanatory diagram showing an operation amount.

FIG. 3 is a sectional view of a conventional example.

4A and 4B show another conventional example, in which FIG. 4A is a sectional view and FIG. 4B is an enlarged sectional view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder tube 2 1st piston 3 Small diameter tube 4 2nd piston 5 Through hole 6 Communication hole 7 Port 8 Piston rod 9 Pressure oil 10 Check valve 11 Elevator car 15 Valve body 16 Valve shaft 17 Valve hole 18 Guide hole 19 Through hole 20 Communication hole 21 Spring

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B66B 1/04 B66B 9/04

Claims (1)

(57) [Claims] 1. A first piston is provided in a vertically installed cylinder tube so as to be movable up and down, a small diameter tube extends from the first piston, and the small diameter tube protrudes from an upper end of the cylinder tube so as to be capable of changing a projection amount. The second piston is provided in the small-diameter tube so as to be movable up and down.
The piston rod extends upward from the piston, the piston rod protrudes from the upper end of the small-diameter tube so that the amount of protrusion can be freely changed, a through hole penetrates through the second piston, and a communication hole that communicates the inside and outside of the small-diameter tube with the small-diameter tube. A port is formed at a lower portion of the cylinder tube for introducing a hydraulic oil that raises the first piston, and is formed at an upper portion of the first piston between the cylinder tube and the small-diameter tube and between the small-diameter tube and the piston rod. In a hydraulic elevator in which pressurized oil is sealed and a first piston is provided with a check valve for replenishing hydraulic oil of a certain pressure or more from a bottom side of a cylinder tube to a rod side of a cylinder tube, an elevator car connected to an upper end of a piston rod is provided. The first piston is forcibly lowered using the operation system further below the lowermost reference position, and The structure of the check valve for generating a negative pressure on the pressure oil side sealed above and replenishing the hydraulic oil to the pressure oil side in the negative pressure state, wherein the valve element moves to the valve element of the check valve. The valve shaft extends in the direction, and a guide hole for slidably holding the valve shaft in the first piston forming the valve hole is formed with the same diameter as the valve hole, and one end side is formed inside the valve shaft.
Forming a communication hole communicating with the port and forming a communication hole communicating with the other end side of the communication hole and communicating with the outside of the valve shaft in the radial direction of the valve shaft on the valve shaft side from the valve body; A check valve for correcting a stroke of a hydraulic elevator, wherein a valve body is biased by a spring in a direction to close a valve hole.