JPH0371583B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of assembling a valve, such as a bellows valve, in which the connection between a valve stem and a valve body is improved.

[Prior Art] For example, in a conventional bellows valve, as shown in FIG.
Body main body 3 through which the fluid used flows through the vertical movement of
The valve body 6 that sets the communication port 5 of the flow passage 4 in the inner part to a fully closed position, an intermediate position, or a fully open position is moved accordingly, and the primary sealing part around this valve body 6 and the valve stem 2 is In addition to sealing with a bellows 7 that separates the working fluid from the atmosphere, a secondary sealing portion with the bonnet 8 around the valve stem 2 inserted into the body main body 3 is sealed with a gland packing 9, and this gland Connect the packing 9 to the gland plate 10, gland bolt 11 and gland nut 1.
Some have a configuration in which additional tightening is possible using a gland bush 13 that is pushed in and adjusted in step 2.

When such a bellows valve is assembled by inserting the tip end 2a of the valve stem 2 into the insertion hole 61 of the valve body 6 in a loosely fitted state and connecting them to each other so as to be rotatable, as shown in FIG. A snap ring 14 made of spring steel and having an outer diameter larger than the inner diameter of the insertion hole 61 of the valve body 6 is installed in the first annular groove 21 formed stepwise on the outer periphery of the tip 2a of the valve stem 2. Assembled in advance, this snap ring 14 is elastically contracted while being pushed along the tapered opening 61a of the insertion hole 61 of the valve body 6 when inserted, as shown in FIG. At present, this is accomplished by expanding the diameter of a second annular groove 62 formed on the inner periphery at a corresponding position and engaging the two.

[Problems to be Solved by the Invention] However, in the conventional valve assembly method described above, when inserting the tip end 2a of the valve stem 2 into the insertion hole 61 of the valve body 6, the snap spring 14 is elastically contracted. In addition, it is not only necessary to chamfer the insertion hole 61 of the valve body 6 into a tapered opening 61a, but also to elastically contract the snap ring 14 while pushing the tip end 2a of the valve stem 2 into the insertion hole 61 of the valve body 6. This in itself has become a difficult task.

In addition, the snap spring 14 is inserted into the insertion hole 6 of the valve body 6.
If a certain degree of plastic deformation occurs in the snap spring 14 when passing through the taper opening 61a of the snap ring 1,
The diameter of the snap spring 14 is not expanded sufficiently, and the insertion hole 6
1 becomes unstable in engagement with the second annular groove 62, and when the valve stem 2 is pulled up, the valve stem 2 is pulled up from the valve body 6.
There was a problem that the reliability of the connected state was poor because there was a risk of it coming off.

[Object of the Invention] The present invention was made under the above circumstances, and its purpose is to easily connect the valve stem and the valve body, and to improve the reliability of the connected state. Our objective is to provide a bellows valve that allows this.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention has provided that the tip of the valve stem, which moves up and down by the rotation of the handle, is connected to the communication port of the fluid flow path in the body main body. In the method for assembling a valve, the valve is rotatably connected via a snap spring that is loosely inserted into an insertion hole of a valve body to be set at a fully closed position, an intermediate position, or a fully open position and engaged between the two. A snap spring formed of a wire made of a shape memory alloy is wound in advance in a first annular groove formed stepwise on the outer periphery of the tip of the valve stem, and this snap spring is attached to the valve body of the tip of the valve stem. After being inserted into the insertion hole, the diameter is expanded by heating and engaged in a second annular groove formed on the inner periphery of the insertion hole.

[Function] That is, the present invention has the above-mentioned configuration, and a snap ring made of a shape memory alloy wire is wound around the first annular groove formed at the tip of the valve stem. After inserting the tip of the snap ring into the insertion hole formed in the valve body, the snap spring is heated to expand its diameter to its original shape so that it engages with the second annular groove formed in the insertion hole of the valve body. As a result, the valve stem and valve body can be assembled smoothly and easily, and the reliability of their mutual connection is increased.

[Example] Hereinafter, the present invention will be described in detail with reference to an example shown in FIGS. 1 and 2. In the illustrated embodiment of the present invention, the same reference numerals are used for the parts having the same structure as the conventional valve structure shown in FIGS. 3 to 5, and the explanation thereof will be omitted.

That is, as shown in FIG. 1, the present invention provides a first annular groove 21 formed stepwise on the outer periphery of the tip 2a of the valve stem 2, and a snap ring 30 formed in advance with a wire made of a shape memory alloy. As shown in FIG. 2, after inserting the tip end 2a of the valve stem 2 into the insertion hole 61 of the valve body 6, the diameter of the snap ring 30 is expanded by heating, and the diameter of the snap ring 30 is expanded to fit around the inner periphery of the insertion hole 61. This is engaged in the second annular groove 62 formed, thereby making it possible to assemble the valve stem 2 and the valve body 6 smoothly and easily, and also to ensure that they are not mutually connected. This makes it possible to improve the reliability of the connected state.

[Effects of the Invention] As is clear from the above description, according to the present invention, the tip of the valve stem, which moves up and down by the rotation of the handle, is completely closed off to the communication port of the fluid flow path in the body main body. In the method for assembling a valve, the valve stem is inserted loosely into an insertion hole of a valve body to be set at a position, an intermediate position, or a fully open position, and is rotatably connected via a snap spring that engages between the two. A snap spring made of a wire made of a shape memory alloy is wound in advance in a first annular groove formed stepwise on the outer periphery of the tip of the valve rod, and the snap spring is inserted into the valve body at the tip of the valve stem. After being inserted into the hole, the diameter is expanded by heating and engaged in the second annular groove formed on the inner periphery of the insertion hole, making it possible to assemble the valve stem and valve body smoothly and easily. This has the excellent effect of increasing the reliability of the mutually connected state.

[Brief explanation of drawings]

FIGS. 1 and 2 are explanatory diagrams of essential parts showing an example of an assembled state of a valve stem and valve body in a valve according to the present invention, and FIG. 3 is a vertical sectional side view of essential parts showing an example of a conventional bellows valve. , FIG. 4, and FIG. 5 are explanatory diagrams showing the assembled state of the conventional valve stem and valve body. 1... Handle, 2... Valve stem, 2a... Tip, 21
...first annular groove, 3...body main body, 4...flow path,
5...Communication port, 6...Valve body, 61...Insertion hole, 62...Second annular groove, 30...Snat spring.

Claims (1)

[Claims] 1. The tip of the valve stem, which moves up and down with the rotation of the handle, is loosely fitted into the insertion hole of the valve body that sets the communication port of the fluid flow path in the body to the fully closed, intermediate, or fully open position. In the method for assembling a valve rotatably connected via a snap spring that is inserted into the valve stem and engaged between the two, a first annular groove formed in a stepped manner on the outer periphery of the tip end of the valve stem is preliminarily inserted. A snap ring made of a wire made of a shape memory alloy is wound, and after the snap ring is inserted into the insertion hole of the valve body at the tip of the valve stem, the diameter is expanded by heating to form it on the inner periphery of the insertion hole. A method for assembling a valve, characterized in that the valve is engaged in a second annular groove.