JPS6321817Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sag prevention structure for a stop valve used during injection molding of liquid rubber material or injection of other liquid materials.

An example of a stop valve commonly used in the past is shown in FIG. 1. A valve body 3 made of a spherical or cylindrical body is rotatably supported in the middle of a conduit 2 provided in a housing 1. The valve body 3 is rotated so as to close the fluid flow path 4 provided to pass through the pipe 2 and the pipe 2, thereby blocking the flow. In addition, 5 is an upper mold for rubber molding, and 6 is the same lower mold, and liquid rubber is poured into molding cavities 7 provided in both molds 5 and 6 to produce a rubber molded product.

However, in the case of the conventional stop valve as described above, when the injection of the liquid material is completed and the valve body 3 is rotated to close the pipe line 2 as shown in the figure, the pipe line below the valve body 3 There is a disadvantage that the residual pressure inside 2' causes sag 8. Who's next 8
The lower the viscosity of the liquid material, the more likely it is to occur earlier, and it will fall onto the upper mold 5 after injection, resulting in stains and a decrease in the precision of the product.

The purpose of the present invention is to eliminate the drawbacks of the conventional stop valves and provide a stop valve that does not cause dripping after the valve body is closed. A spherical or cylindrical valve body is positioned in the middle of a conduit provided in a housing and rotatably fitted into the housing, and rotation of the valve body opens the conduit. Alternatively, in a stop valve that closes, a recess extending in the rotation direction of the valve body is provided in a part of the outer surface of the valve body, and the valve body is rotated to close the pipe line between the recess and the housing side. A hollow part is formed that faces the fluid outlet side of the pipe when the pipe is rotated, and a hollow part is provided that protrudes from the housing side into the hollow part to keep the hollow part airtight in the rotation direction. When the valve body is rotated in a direction to close the conduit, a space on one side of the protrusion in the hollow portion communicates with the fluid discharge port side of the conduit. It is an object of the present invention to provide a stop valve for preventing fluid dripping, which is characterized in that the volume of the space is expanded.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. Fig. 2 is a front cross-sectional view of the stop valve based on the present invention, and Fig. 3 is a side cross-sectional view of the same portion. The housing body 13 is a spherical valve body with a passage 14 formed therethrough. The valve body 13 is located in the middle of the pipe line 12 and is rotatably fitted into the housing main body 11 via a non-rotatable guide member 15, and by the rotation, the valve body 13 A valve body 13 is adapted to open or close the pipe line 12. Also,
By providing a recess 19' extending in the rotating direction of the valve body 13 in a part of the outer surface of the valve body 13, the valve body 1 is provided between the recess 19' and the housing body 11 side.
A hollow portion 19 is formed that moves in accordance with the rotation of 3. Reference numeral 16 denotes a protrusion that protrudes from the guide member 15 into the hollow portion 19, and is in airtight sliding contact with the inner surface of the recess 19' constituting the hollow portion 19. In other words, the protrusion 16 is The hollow part 19 is divided into two spaces 19a and 1 in the rotation direction.
It is divided into 9b. 17 is a drive shaft for rotating the valve body 13, and 18 is a lever fixed to the outer end of the drive shaft 17.

Next, the operation of the stop valve having the above structure will be explained. Liquid rubber usually has a considerable viscosity and flows in the channel 14 in the pipe 12 and valve body 13, as shown in FIG. After an appropriate amount of liquid has been supplied, the lever 18 is operated to rotate the valve body 13 and close the conduit 12. In addition, 21a is an upper mold for rubber molding, and 21b is a lower mold. As shown in FIG. 5, when the valve body 13 is rotated in a direction to close the conduit 12, the flow path 14 of the valve body 13 becomes discontinuous with respect to the conduit 12 due to the rotation. The pipe line 1
2 is closed, and further, due to the movement of the hollow part 19 accompanying the rotation, the space 19a on one side of the protrusion 16 in the hollow part 19 is closed to the fluid outlet side 1 of the pipe line 12.
2', and the volume of the space 19a expands with the rotation. After the conduit 12 is closed, liquid rubber remains on the fluid outlet side 12' of the conduit 12. Since atmospheric pressure is acting on the lower end surface 22 of the liquid rubber from the lower end opening (fluid outlet) of the pipe line 12, this liquid rubber is sucked into the space 19b where the pressure becomes low as the volume expands. This prevents the liquid rubber from dripping after the pipe line 12 is blocked.

Further, the volume of the space 19b on the other side of the protrusion 19 in the hollow portion 19 decreases with the rotation, and the air inside the space 19b is discharged from the ventilation hole 20 to the external space. Note that the valve body 13 is rotatable until the rear end of the recess 19' in the rotation direction comes into contact with the protrusion 16.

As explained above, the stop valve of the present invention has a hollow part that moves with the rotation of the valve body when the valve body is rotated to close the pipeline, and a protrusion that protrudes into the hollow part from the housing side. The volume of the space thus formed changes with the rotation, and when the valve body is rotated in the direction of closing the pipe, the space communicates with the fluid outlet side of the pipe and the volume increases. By enlarging it, it is possible to prevent fluid from dripping after the pipe is blocked, which has the advantage of preventing equipment from being contaminated by dripping of liquid material for molding and improving the precision of molded products. has.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic sectional view showing an example of a conventional stop valve, FIG. 2 is a front sectional view of the stop valve according to the present invention, and FIG. 3 is a side view of the same part. 4 is a longitudinal sectional view of the stop valve according to the present invention, and FIG. 5 is a longitudinal sectional view of the stop valve shown in FIG. 4 in a closed state. 11...Housing body, 12...Pipe line, 13
... Valve body, 14 ... Channel, 15 ... Guide member,
16... Stoppa, 19... Hollow part.

Claims (1)

[Scope of utility model registration request] A spherical or cylindrical valve body 13 having a fluid passage 14 formed therethrough is positioned in the middle of a pipe line 12 provided in a housing and is rotatably fitted into the housing. In a stop valve that opens or closes the pipe line 12 by rotating the body 13, the valve body 13 is attached to a part of the outer surface of the valve body 13.
A recess 19' extending in the direction of rotation of the pipe 12 is provided between the recess 19' and the housing side, and when the valve body 13 is rotated to close the pipe 12, the fluid discharge port side of the pipe 12 is provided. a protrusion 16 that forms a hollow part 19 that is located facing 12', and that protrudes into the hollow part 19 from the housing side and partitions the hollow part 19 airtightly in the rotation direction; is provided, and when the valve body 13 is rotated in the direction of closing the pipe line 12, the protrusion 1 in the hollow portion 19
A stop valve for preventing dripping of fluid, characterized in that a space 19a on one side of the pipe 12 communicates with the fluid outlet side 12' of the pipe line 12, and the volume of the space 19a is expanded.