JPH0330301Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a plunger for a plastic injection container that is used to extrude stored silicone or the like.

``Conventional technology and problems'' Conventionally, when fitting an injector container made of silicone or the like with a plunger, the tolerance range during processing was both ±0.15 mm, making it extremely difficult to control dimensions during plastic molding.

In addition, if there is a slight deviation in the dimensional tolerance, and if the plunger diameter is large, the movement of the air gun will become stiff during extrusion, making it impossible to slide stably, resulting in uneven discharge amount, and conversely, the plunger For smaller diameters, the problem is even more serious;
There was a risk that air would enter the container cylinder through the gap and harden the contents such as silicone, and there was also a problem that air flowing in through the gap would be discharged from the injection opening when the air gun was pushed out.

The above-mentioned problems have frequently occurred in the past, and there is currently an urgent need for some kind of countermeasure in this industry.

``Means for Solving the Problems'' Therefore, the present invention is designed to fit a cylindrical injector container from one end of the container tube, and to transfer the contents from the small diameter injector opening at the other end of the container tube. In a plunger for an injection container, the plunger is integrally equipped with a head whose outer diameter is approximately equal to the inner diameter of the container cylindrical portion, and the outer diameter of the plunger is larger than the inner diameter of the container cylindrical portion in the extrusion direction. Expandable flexible first
a flange-like protrusion, and a conductive path that can conduct the contents of the container head to the extrusion side of the flange-like protrusion is provided in the head, and an outer periphery of the plunger behind the first collar-shaped protrusion. It is an object of the present invention to provide a plunger for a plastic injection container, which is provided with a flexible second flanged projection that can be tilted rearward and larger than the inner diameter of the container cylinder.

"Operation" When inserting the plunger of the present invention having the above-mentioned configuration from one end of the container cylinder, the plunger head first fits into the inner wall of the cylinder, thereby setting the insertion direction correctly. Therefore, the first brim-like projection at the rear of the head is inserted as it is from the end of the cylinder and guided so as to fit smoothly into the cylinder. Next, the second brim-like projection is regulated in its insertion direction by the head and the first brim-like protrusion, and is smoothly fitted into the container cylindrical portion while tilting backward with flexure, and is tightly fitted to the inner wall of the cylindrical portion. I will do it. and,
When the plunger fits into the container cylindrical portion and pushes out the contents, the contents that have passed through the conduit in the head to the pushing side of the first flanged projection press the flanged projection outward. , because the brim-shaped projection is bent by the pressing force and comes into close contact with the inner wall of the cylindrical portion, a large interference can be obtained with a small force during sliding, and the first
Since the flanged projection receives extrusion pressure on the extrusion side as it is inserted, it is possible to reliably prevent air from entering when using the air gun. Furthermore, the second
The brim-shaped projection bends backward and comes into close contact with the inner wall of the container, so it is possible to reliably prevent air from entering when using an air gun, and it is also possible to obtain a large interference with a small force when sliding. .

Therefore, in fitting the injection container and the plunger, the tolerance range can be set wide by the amount of deflection of the brim-like projection. Furthermore, although the bottom of the injection container has been sealed with wax to prevent air from entering, the present invention allows for reliable sealing with the first and second brim-shaped protrusions. It can be made unnecessary.

"Embodiment" In the figure, 1 is a plunger main body having a head having an outer diameter approximately equal to the inner diameter of the injection container, and the head 2 is formed by closing with slight flesh pressure, and the rear of the head 2 is A bottom portion 3 integrally provided with the bottom portion 3 is formed to be open downward. 4 is a first brim-shaped projection provided between the head 2 and the bottom 3; a deep groove 5 on the head 2 side and a shallow groove 6 on the bottom 3 side;
It is provided in such a way that it opens toward the extrusion side. The first brim-shaped projection 4 is connected to the grooves 5 and 6.
The groove end diameter D1 (for example, 47.6 mm) is set so that it can be deflected by as much as 1.0 mm, for example, to a diameter of 48.6 mm when expanded. Reference numeral 7 denotes a conduction path provided in the head 2 of the plunger body 1, and is provided so that the contents of the injection container can flow into the concave groove 5 on the extrusion side of the first flanged projection 4 during extrusion. . Therefore, this plunger body 1
When inserted into the cylindrical part of an injection container with an inner diameter of 47.6 mm to 48.6 mm, the contents flowing from the conductive path 7 into the concave groove 5 on the extrusion side of the first flanged protrusion 4 push the flanged protrusion 4. Expanding in the outer circumferential direction, the brim-shaped projection 4 comes into close contact with the inner wall of the container, and a large interference margin can be obtained with a small force during extrusion, thereby preventing air from entering. Further, the dimensional control and molding conditions of the injection container cylindrical portion and the plunger outer diameter can be made easier by the amount of deflection caused by the expansion of the brim-shaped projection 4.

On the other hand, 8 is a second flange-like protrusion provided between the first flange-like protrusion 4 and the bottom part 3, and between the shallow-bottomed groove 6 and the deep-bottomed groove 9 on the bottom part 3 side. It is installed protrudingly. For example, the diameter D2 of the second brim-shaped protrusion 8 is 48.6 mm, and the diameter D1 of the groove ends of the grooves 5 and 6 is 48.6 mm.
While it is 47.6mm, it is set about 1.0mm larger. Therefore, the inner diameter of the plunger body 1 is
When inserted into the cylindrical part of a 47.6 mm to 48.6 mm injector container, the flanged protrusion 8 comes into contact with the inner wall of the container and bends downward, resulting in a large clamping margin being obtained with a small force during extrusion. This prevents air from entering, which makes it easier to control the dimensions of the injection container cylinder and the plunger outer diameter and to control the molding conditions accordingly.

Therefore, at present, the bottom of the injection container is sealed with wax to prevent air from entering, but in the present invention, the first and second flanges 4,
Since the sealing member 8 can be reliably sealed, such a sealing member can also be made unnecessary.

"Effects of the invention" As described above, according to the invention, the container tube part of the cylindrical injection container is fitted from one end,
In the plunger for an injection container, the plunger is integrally provided with a head whose outer diameter is approximately equal to the inner diameter of the container cylinder, the head portion being configured to push out the contents from the small-diameter injection exit opening at the other end of the container cylinder. A flexible first collar-shaped projection that can expand larger than the inner diameter of the container cylindrical portion in the extrusion direction is provided on the outer periphery of the rear part of the head; Because it has a configuration in which a conductive path is provided that can conduct to the extrusion side of the
When fitting the plunger of the present invention from one end of the cylindrical container tube part, the head is fitted in advance and serves as a guide when the subsequent first collar-shaped projection is fitted. The plunger does not come into contact with the cylindrical end and warp, and can be fitted smoothly into the container cylindrical portion with the plunger having a flange-like protrusion, making it easier to attach the plunger to the container.
When fitting the plunger into the container cylinder and pushing it out,
The content that has passed through the conduction path to the extrusion side of the first flanged projection presses the flanged projection, causing the flanged projection to bend and come into close contact with the inner wall of the cylindrical portion, so that the injection container and the plunger are fitted together. In this case, the tolerance range can be set wider by the amount of deflection of the brim-shaped projection. Further, by providing a flexible second brim-like protrusion that can be tilted backwards, which is larger than the inner diameter of the container cylindrical part, on the outer periphery of the plunger behind the first brim-like protrusion, the plunger can be attached to the container cylindrical part. When fitted, the second flanged protrusion bends and comes into close contact with the inner wall of the cylindrical portion, so when fitting the injection container and the plunger, the tolerance range is limited by the amount of deflection of the first and second flanged protrusions. Can be set widely.
Therefore, it is possible to easily manage tolerances and set processing and forming conditions. In addition, when the air gun is pushed out, the first brim-like projection on the outer periphery of the plunger is bent by the pressure of pushing out the contents and comes into close contact with the inner wall of the container, so a large interference can be obtained with a small force during sliding. In addition, since the first flanged protrusion receives strong extrusion pressure on the extrusion side as it is inserted, it is possible to reliably prevent air from entering when using the air gun, while the second flanged protrusion is susceptible to bending. Since it is in close contact with the inner wall of the container, it is possible to obtain a large clamping margin with a small force during sliding, and since the second flanged protrusion bends toward the rear as it is inserted, the first flanged protrusion This also has the effect of reliably preventing air from entering when using an air gun.

[Brief explanation of drawings]

FIG. 1 is a partially longitudinal front view showing an embodiment of the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is an enlarged longitudinal sectional view of the main part thereof. 1... Plunger body, 2... Head, 4...
First flange-like process, 7... Conductive path, 8... Second flange-like process.

Claims (1)

[Scope of utility model registration request] The outer diameter of the cylindrical injection container is fitted from one end of the container tube and the contents are pushed out from the small diameter injection opening at the other end of the container tube. In a plunger for an injection container integrally equipped with an equal head, a flexible first brim-shaped projection capable of expanding in the extrusion direction to a larger extent than the inner diameter of the container cylinder is provided on the outer periphery of the rear of the head of the plunger. On the other hand, a conductive path is provided in the head part to conduct the contents of the container head to the extrusion side of the flanged projection, and an inner diameter of the container cylindrical portion is provided on the outer periphery of the plunger behind the first flanged projection. A plunger of a plastic injection container, comprising a flexible second collar which can be tilted back to a larger extent.