JPH0541792Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an injection valve for powder that is placed in a small injection container containing dry powder contents.

BACKGROUND OF THE INVENTION In valve assemblies that are fixed onto a container containing dry powder, the valve stem must move relative to the container so that the outer surface of the valve stem and other components of the valve assembly are A sliding connection is made between the two. That is, the valve stem is surrounded by a gasket or similar material, but is allowed to slide.

This required relative movement between the valve stem and other fixed parts of the container structure prevents leakage from inside the container at the sealing surface between the outer surface of the valve stem and the circumferential surface of the gasket hole. Otherwise, passage blockage is likely to occur and damage valve function.

There is an aerosol dispenser disclosed in Japanese Patent Publication No. 48-9766 that solves the problems of leakage and blockage of valve devices as described above. According to this, the annular protrusion 54 formed at the intersection of the surfaces 24 and 40 of the valve housing 16 compresses the gasket 38 around the outer periphery of the valve stem with a large supporting force to strengthen the sealing effect, and the sealing effect is strengthened. A lubricating washer 43 is installed around the valve stem on the outside of the cup 10 to eliminate the effect of additional frictional resistance generated on the gasket, and can prevent leakage etc. under the smooth movement of the valve stem. shall be. However, there is still room for improvement in that the above invention relies heavily on lubricating washers.

(Problems to be solved by this invention) This invention has improved performance against leakage from the outer surface of the valve stem and the peripheral surface of the center hole of the sealing gasket that tightly surrounds the valve stem, and The purpose is to provide a powder valve that has a simple structure and is easy to manufacture.

(Means for solving the problem) In order to achieve the above object, the proximal end of the tapered shoulder of the valve stem is engaged with the lower edge of the center hole of the sealing gasket in the non-distributing position of the injection valve, and The piston skirt at the lower end of the valve stem is brought into sliding contact with the piston sliding surface of the housing, and at the distribution position, the orifice is opened into the upper housing chamber of the valve housing. It is characterized in that conduction can be made to the orifice through the outside of the orifice.

Powder that tends to accumulate at the engagement area between the sealing gasket and the valve stem tends to fall off the tapered shoulder of the valve stem, and when it engages the gasket, it sweeps the upper end of the tapered shoulder, causing powder accumulation. disappears. Furthermore, since the close contact portion of the piston skirt is closed before the tapered shoulder portion is sealed, the sealing effect is enhanced.

Below, we will explain the drawings showing the embodiments of the present invention. Fig. 1 is a vertical sectional view of the main parts of the powder valve, in which the valve stem 1 is at the top dead center in the non-dispensing position, and the powder valve is at rest. It shows the condition. FIG. 2 is a longitudinal sectional view of the powder valve in which the valve stem 1 has moved downward and the orifice 2 has opened in the upper chamber 8 of the housing.

In these figures, reference numeral 3 denotes a mountain cap which fixes the outer periphery to the injection container and seals it, and also houses and holds the upper part of the valve assembly within the central bulge 4.

5 is a valve housing, and 6 is a sealing gasket, which is sandwiched and housed between the upper end surface of the valve housing 5 and the inner surface of the top wall 4a of the central bulging portion 4, and the central hole 6a is in tight contact with the outer surface of the valve stem 1. to seal the inside and outside of the valve housing 5. An annular bulge 5a is provided on the upper end surface of the valve housing 5 to compress the sealing gasket 6 and strengthen the sealing effect against the valve stem 1. The valve stem 1 is provided with an enlarged cylindrical portion 7 at its lower portion, and is received by a coil spring 12 disposed on the inner bottom 9a of the valve housing 5.

The enlarged cylindrical portion 7 has a piston skirt 1 at its lower end.
0 are connected in series to make the inner periphery of the valve housing 5 slidable, and a tapered shoulder portion 11 is provided at the upper end, the base end portion 11a of which is engaged with the sealing gasket 6 by the upward force of a spring. Inside the valve housing 5, a housing upper chamber 8 and a lower housing chamber 9 are formed by a piston.
Divide into upper and lower parts. 13 is piston skirt 10
is a piston sliding surface of the valve housing 5 on which the piston slides, and is provided corresponding to the piston skirt 10 at the non-distribution position of the valve stem 1. The piston sliding surface 10 has a short dimension and makes the frictional sliding force of the piston as close to zero as possible. A large-diameter annular recess 14 is provided on the inner peripheral surface of the valve housing 5 continuously below the piston sliding surface 13, and a passage 15 is formed on the outside of the piston skirt 10 and blocked when the valve stem 1 is lowered. The upper chamber 8 and lower chamber 9 of the housing, which had previously been connected to each other, are formed in a communicating state. As mentioned above, 2 is an orifice that penetrates the wall of the valve stem 1, and when the valve stem 1 is lowered, it opens into the housing upper chamber 8 to communicate the inside and outside of the valve housing 5. At times, it opens above the sealing gasket 6 and is shut off from the upper chamber 8 of the housing. Opening and closing of the orifice 2 of the valve stem 1 with respect to the upper chamber 8 of the housing allows communication and isolation between the upper chamber 8 and the lower chamber 9 of the housing. It corresponds to various timings of piston opening and closing. At any timing, when the orifice 2 is cut off from the housing upper chamber 8, the valve stem 1 is placed at the top dead center, and the piston collar 10
By blocking the upper chamber 8 and lower chamber 9 of the housing, leakage can be effectively prevented.

(Function/Effect) As is clear from the above, in the case of a powder valve, when the valve stem 1 is pushed down from the resting state shown in FIG. A passage 15 is formed on the outside of the housing 10 to communicate the upper chamber 8 and the lower chamber 9 of the housing. Before and after this communication is established, the orifice 2 of the valve stem 1 opens into the housing upper chamber 8 to discharge the powder inside the container to the outside. When the pressing force on the valve stem 1 is released, the coil spring 12 causes the stem 1 to rise, thereby shutting off the upper and lower chambers of the housing and, before and after this, closing the orifice from the upper chamber of the housing. When the valve stem 1 reaches the top dead center, the base end 11a of the tapered shoulder 11 tends to slightly enter the center hole 6a of the sealing gasket 6.
As the lower hole edge of the center hole 6a scrapes the outer surface of the proximal end, deposits that tend to occur at the corners are scraped off. Therefore, in addition to the tapered shape, powder is not easily deposited on the tapered shoulder portion 11, and the sealing effect of the gasket that is in close contact with the outer surface of the valve stem can be favorably supported. Moreover, since the gasket seal against the valve stem is maintained in the upper chamber of the housing which is isolated from the inside of the container, leakage can be effectively prevented.

[Brief explanation of the drawing]

FIG. 1 shows a longitudinal sectional view of the powder valve in the non-dispensing position, and FIG. 2 shows a longitudinal sectional view of the powder valve in the dispensing position. 1... Valve stem, 2... Orifice, 5...
...Valve housing, 6...Sealing gasket, 8
...Housing upper chamber, 9...Housing lower chamber, 1
0...Piston collar, 11...Tapered shoulder, 1
3... Piston sliding surface, 14... Large diameter annular recess, 15... Passage.

Claims (1)

[Scope of utility model registration request] a sealing gasket surrounding and sealing the valve stem at the center bore surface;
The valve stem is attached to the gasket so as to be movable in the axial direction between a dispensing position when the orifice of the valve stem is in communication with the inside of the container and a non-dispensing position when the orifice is in a position to cut off the flow. In the injection valve, the lower part of the valve stem 1 is provided with an upper end tapered shoulder part 11 that engages with the lower edge of the center hole 6a of the sealing gasket 6, and an enlarged cylindrical part 7 having a piston collar 10 at the lower end, and a valve housing 5. has the piston sliding surface 13 of the piston collar 10 and the piston collar 1 on the inner peripheral surface.
An injection valve for powder, characterized in that a large-diameter annular recess 14 is provided on the outside of the piston to form a passage 15 that communicates an upper chamber 8 and a lower chamber 9 of the housing divided into the piston.