JPH08229842A - Method of removing/fitting piston assembly in control valve - Google Patents

Abstract

PURPOSE: To provide a removing/fitting device for a piston assembly in a control valve enabling even one person to safely remove/fit the piston assembly. CONSTITUTION: Two fastened bolts are loosened and removed, and bolts 10 are screwed therein. After these bolts 10 are supported by a plate 11 with a jack bolt 12 screwed therein, remaining fastened bolts are loosened and removed by the jack bolt 12 in a condition that the piston assembly are pressed. The jack bolt 12 is then rotated to gradually pull out the piston assembly. Reverse procedure is peformed at the time of mounting the piston assembly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for attaching and detaching a piston assembly in a control valve used in a hydraulic unit of a hydraulic elevator.

[0002]

2. Description of the Related Art For example, a control valve is used in a hydraulic unit of a hydraulic elevator to control the amount and pressure of hydraulic oil sent from the hydraulic unit to a hydraulic jack. This control valve includes a valve body having a plurality of openings, an upside down valve assembly housed in one of the openings, a down piston assembly housed in another of the openings, another opening 1
It is composed of a bypass piston assembly and the like housed in one, and the bypass piston assembly is composed of a compression spring, a bypass piston, a closer, a bypass adjusting bolt, a fixing flange, and the like.

Conventionally, when the bypass piston is pulled out or inserted into the opening for inspection or repair, that is, when the bypass piston is detached, a force of 50 kgf is applied as soon as the fastening bolt is removed from the valve body. With a compression spring, hold the bypass piston so that it does not come out with force, loosen the bolt, and remove it.Also, when inserting it, one of the workers overcomes the force of the compression spring and pushes it in. The worker had to screw in the fastening bolt and tighten it.

[0004]

As described above, two workers are required to attach and detach the bypass piston assembly including the compression spring. In addition, one person presses down and the other person removes or attaches the bolt, so if the breathing of the two does not match, the situation where the bypass piston assembly pops out at the moment when the bolt is removed may occur. .

An object of the present invention is to provide a method for attaching and detaching a piston assembly in a control valve, which enables one person to safely remove the piston assembly.

[0006]

The above object is to accommodate a piston assembly, in which a compression spring, a piston and a closer are arranged in this order, in an opening of a valve body, and press the piston assembly on the end face of the opening. In a method for attaching and detaching a piston assembly in a control valve in which a flange to be kept is fixed by four or more fastening bolts, at least two fastening bolts are loosened and removed when detaching the piston assembly. Screw the other bolts into the bolt holes respectively, support the plate with the jack bolts screwed on these bolts, and after the tip of the jack bolt contacts the piston assembly, loosen the rest of the fastening bolts and remove it. , Rotating the jack bolt to gradually withdraw the piston assembly while applying a force that opposes the compression spring to the piston assembly. It is achieved by inserting the.

[0007]

Since the present invention is the method as described above, when the piston assembly is attached or detached, the remaining fastening bolts are removed while applying a force against the compression spring to the piston assembly, and then the jack bolt is operated. By doing so, the piston assembly can be pulled out gradually. In addition, the piston assembly can be inserted by operating the jack bolt in the direction opposite to that at the time of extraction.

As described above, the jack bolt supported by the valve body applies a force against the compression spring to the piston assembly, so that even if all the fastening bolts are removed, the piston assembly does not pop out and the piston assembly can be safely operated. Desorption work can be performed by one person. Further, the piston assembly can be gradually pulled out or inserted, and the piston assembly can be prevented from being damaged.

[0009]

Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 is a perspective view showing a state of attachment and detachment, and FIG. 2 is an explanatory view of a control valve.

First, the main structure of an aluminum or aluminum alloy control valve to which the present invention is applied will be described with reference to FIG. In addition, in FIG. 2, a check valve assembly,
Also, the down piston assembly is kept stored and only the bypass piston assembly is extracted.
The control valve includes a valve body 1 having a plurality of openings,
Check valve assembly 2 housed in one of the openings, down piston assembly 3 housed in the other of the openings, bypass piston assembly housed in the other of the openings Equipped with goods.

The bypass piston assembly comprises a compression spring 4, a bypass piston 5, a closer 6, a bypass adjusting bolt 7 screwed to the closer 6, and a flange 8. The bypass piston assembly is housed in the opening in the order shown. There is. Reference numeral 9 is a fastening bolt for the flange 8, and in this case, four fastening bolts are provided.

Next, referring to FIG. 1, description will be given of a procedure for attaching and detaching the piston assembly in the control valve according to the embodiment of the present invention.

When the piston assembly is pulled out for inspection or replacement of the seal ring, (1) Loosen all the fastening bolts 9.

(2) Further loosen and remove the two fastening bolts 9 (two located symmetrically with respect to the bypass adjustment bolt 7).

(3) An aluminum bolt 10 is screwed into each of the two bolt holes from which the fastening bolt 9 has been removed.

(4) The holes 11a and 11b are provided, and the holes 11a
And a plate 11 having a jack bolt 12 screwed into the bolt 10 at an intermediate position between the bolts 11 and 11b (holes 11a, 1
The bolt 10 is inserted into 1b), and the nut 13 is screwed into both bolts 10 to support the plate 11 on both bolts 10.

The bolt 10 may be inserted into the holes 11a and 11b of the plate 11 and then the end of the bolt 10 may be screwed into the bolt hole after the fastening bolt 9 is removed.

(5) Insert the metal fitting 14 between the tip of the jack bolt 12 and the flange of the piston assembly, and rotate the jack bolt 12 to advance it.
Apply a light pressing force to the piston assembly.

(6) Remaining fastening bolt 9 (2 in this case)
Loosen) and remove.

(7) Rotate the jack bolt 12 by rotating it, and gradually withdraw the piston assembly while applying a force against the compression spring. Withdrawal is completed by retracting the compression spring until it is fully extended.

When mounting the piston assembly after inspection or after replacing the seal ring with a new one, (1) a state in which the metal fittings 14 are in contact with the flange after the parts of the piston assembly are sequentially inserted into the openings. The jack assembly 12 is advanced by rotating the jack bolt 12 and overcomes the compression spring to push the piston assembly into the opening. If the flange of the piston assembly is pushed in until it comes into close contact with the valve body 1, stop the rotation of the jack bolt 12.

(2) Screw the two fastening bolts 9 into the screw holes of the valve body 1 and lightly tighten them.

(3) Rotate the jack bolt 12 to retreat, remove the metal fitting 14, loosen the bolt 10, and remove from the bolt hole.

(4) Tighten the fastening bolt 9 by screwing it into the bolt hole from which the bolt 10 has been removed.

(5) Tighten the four fastening bolts 9 in order little by little so that the tightening force is even.
This completes the mounting.

In the above embodiment, since the bolt made of aluminum or its alloy is used, even if it is screwed into the screw hole for the fastening bolt of the valve body, the screw surface is hardly damaged.

Further, the operation of attaching and detaching the piston assembly is performed by the jack bolt and the bolt itself is not rotated, so that the threaded surface of the screw hole for the fastening bolt is not worn.

[0029]

As described above, according to the present invention, the piston assembly can be safely attached / detached by one person without using a large-sized attachment / detachment device.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a method for attaching and detaching a piston assembly in a control valve of the present invention.

FIG. 2 is an explanatory diagram of a control valve.

[Explanation of symbols]

 1 Valve Body 4 Compression Spring 5 Bypass Piston 6 Closer 7 Bypass Adjustment Bolt 8 Flange 9 8 Tightening Bolt 10 Aluminum Bolt 11a, 11b Hole 12 Jack Bolt 13 Nut 14 Fitting

Claims (1)

[Claims] 1. A piston assembly in which a compression spring, a piston and a closer are arranged in this order is housed in an opening of a valve body, and four or more flanges for holding the piston assembly at the end face of the opening are fastened. In the method of attaching and detaching the piston assembly in the control valve fixed by bolts,
When detaching the piston assembly, at least two of the fastening bolts are loosened and removed, and then another bolt is screwed into each of these bolt holes, and a plate in which a jack bolt is screwed is supported by these bolts. After abutting the tip of the jack bolt with the piston assembly, loosen and remove the rest of the fastening bolt, rotate the jack bolt, and apply force to the piston assembly against the compression spring. A method for attaching and detaching a piston assembly in a control valve, characterized by gradually extracting or inserting the product.