JP2005074974A - Joining structure of members in applicator - Google Patents

Abstract

[Objective] To provide a joining structure that is easy to assemble and has a small number of parts, which prevents compressed gas from leaking even when an external force such as a drop impact is applied.
[Configuration] A coating liquid storage chamber of an applicator that encloses in a compressed state a gas that supports discharge of the coating liquid by pressure together with the coating liquid, and a joint portion at a cylindrical opening of the coating liquid storage chamber. It is a joint structure with a member that is attached so as to be airtight, and it forms a fitting protrusion that fits over the joint of both members, and the inside of the coating liquid storage chamber is more inward than the fitting protrusion. A joint structure in which an airtight sealing contact portion is arranged at a position.

Description

  The present invention relates to a joining structure for members in an applicator that encloses a gas together with a coating solution in a compressed state and supports discharge of the coating solution by the pressure of the gas inside a coating solution storage chamber communicating with a coating destination. .

Conventionally, compressed gas is sealed in a coating liquid storage chamber for storing a coating liquid such as ink for writing instruments, correction liquid, glue, liquid cosmetics, etc., and the force by which this compressed gas pushes the coating liquid is a support for liquid discharge. When connecting a tail plug, an application destination, a joint member to the application destination, or the like to the application liquid storage chamber in the applicator to be formed, it is necessary to ensure sealing between the attached member and the application liquid storage chamber. For example, when a tail plug is fixed to a rear end opening of a cylindrical member that is used as a coating solution storage chamber, an adhesive substance or a rubber elastic body is disposed at the joint, and a metal member is disposed at the rear thereof. For example, there are known ones that have been secured with a seal (see Patent Document 1) and those that have welded seams (see Patent Document 2).
Japanese Utility Model Publication No. 58-166490 JP-A 61-027298

  However, in the case of using a rubber-like elastic body, since the number of parts increases, there is a drawback that the productivity is lowered and the cost is increased.

  In the case of welding, when melted, the pressure of the compressed gas causes the gas to leak out from the melted portion and generate holes. Further, there is a disadvantage that productivity is lowered by heat-welding after press-fitting the tail plug.

  The present invention relates to an application liquid storage chamber of an applicator that encloses in a compressed state a gas that supports discharge of the application liquid by pressure together with the application liquid, and a joint portion between the cylindrical opening of the application liquid storage chamber. Is formed in a joint structure with a member that is attached so as to be airtight, and a fitting projection that crosses over the joint portion of both the members to form a fitting is formed, and the inside of the coating liquid storage chamber is more than the fitting projection. The gist of the joining structure of the members in the applicator in which the hermetic sealing contact portion is disposed in the opposite position.

  Deformation due to drop impact or the like by forming a hermetic sealing contact portion, such as contact between the circumferential protrusion and the surface, at the inner position of the coating liquid storage chamber rather than the fitting protrusion that makes overcoming fitting Is less susceptible to the influence of the vicinity of the opening, and the airtightness is less likely to be impaired. Therefore, it is not necessary to use a rubber-like elastic body as a separate member or to melt the member.

  For example, it is suitable for application to a liquid-tight / air-tight fitting structure between a shaft tube and a tail plug of a writing instrument in which compressed gas is sealed inside a container and ink discharge is supported by the force of this compressed gas. This is a joint structure of members that act on the inner part, and the circumferential protrusions that come into airtight contact with the fixing fitting protrusions are fixed to the tail plugs that become the inner members, and the circumferential protrusions that come into airtight contact are inserted into the inner position of the shaft cylinder more. A fitting inner protrusion corresponding to the fitting protrusion is formed in the vicinity of the opening on the inner wall of the shaft tube so that the fitting fitting protrusion and the fitting inner protrusion are overcome. In a state where the fixing is completed, the circumferential protrusion is circumferentially brought into contact with the hermetic contact portion of the inner wall of the shaft tube, so that liquid tightness and air tightness are ensured.

An example will be described below with reference to the drawings.
What is shown in FIG. 1 is an example of a correction applicator that contains correction liquid 1 in which methylcyclohexane is used as a main medium and a white pigment such as titanium oxide is dispersed.
The correction liquid 1 is accommodated in a coating liquid storage chamber 2 that is an injection-molded product of polybutylene terephthalate serving as a coating liquid storage section. The coating liquid storage chamber 2 is made of methylcyclohexane, which is the main medium of the correction liquid 1, so that it does not change its shape due to swelling, dissolution, decomposition, etc., and any material other than polybutylene terephthalate as long as it has a low gas permeability. In addition, nylon 12, ethylene vinyl alcohol copolymer or the like can be used. In particular, in order to make the remaining amount of the correction coating solution 1 visible from the outside, transparent such as polyethylene terephthalate, nylon 6, amorphous nylon, microcrystalline nylon, semi-aromatic nylon, polyacrylonitrile, etc. It can also be a material.

  Connected to the tip of the coating liquid storage chamber 2 is a ball holder 4 holding a ball 3 rotatably as a coating destination member. The ball 3 is urged forward by a coil spring 5 and functions as a valve that controls liquid discharge by being in liquid-tight contact with the inner edge of the ball holder 4.

  Further, a liquid mainly composed of an organic medium such as polybutene, α-olefin, and glycerin that contacts the rear end interface of the correction liquid 1 and moves following the interface of the correction liquid 1 that moves as the coating liquid is consumed. Followers 6 are arranged in layers. The follower 6 has a viscosity higher than that of the correction liquid 1 and regulates the backward movement of the correction liquid 1 and plays a role of preventing the correction liquid 1 from flowing backward.

  What is indicated by reference numeral 7 is a bottomed cylindrical floating body made of a synthetic resin immersed in the follower 6. The arrangement of the floating body 7 is not necessarily required when the inner diameter of the coating liquid storage chamber 2 is small, but is particularly effective when the inner diameter is large, and is arranged together with the follower 6 to strengthen the backflow prevention function. ing.

Inside the coating liquid storage chamber 2, the space behind the floating body 7 is filled with compressed gas 8, and the rear end opening of the coating liquid storage chamber 2 is sealed with a tail plug 9. The rear space of the floating body 7 is set to a pressure state higher than the atmospheric pressure, and the follower 6 is pushed forward to push the correction liquid 1 forward to assist in discharging the liquid. The tail plug 9 has a shape of a bottomed cylinder having an opening on the inner side of the coating liquid storage chamber 2, and allows gas permeation of polybutylene terephthalate, nylon, ethylene vinyl alcohol copolymer, polyacrylonitrile, etc. It is a member obtained from an injection molded product of a synthetic resin having low properties or a metal cutting product. The compressed gas 8 is preferably a gas from which dust and moisture have been removed. This is to prevent deterioration of the follower 6 due to foreign matters.
Reference numeral 10 denotes a cap that is detachably attached to the tip of the coating liquid storage chamber 2 and has a function of protecting the coating section during storage and preventing drying.

  As a method of sealing the compressed gas in such a coating liquid storage chamber, the tail plug 9 is inserted from the rear end opening of the coating liquid storage chamber 2 to a midway position and temporarily set in a pressurized chamber. The pressurized gas is introduced into the coating liquid storage chamber 2 from the groove-like gas inlet 9 f formed in the tail plug 9. Thereafter, the tail plug 9 is completely pushed into a predetermined position where it can be completely sealed, and the compressed gas is sealed.

  FIG. 2 is an enlarged view of a portion I in FIG. 1 and shows a joined state between the tail plug 9 and the coating liquid storage chamber 2. Three annular fitting inward projections (2a, 2b, 2c from the opening end side) are formed inside the rear end opening of the coating liquid storage chamber 2, and each fitting is formed on the outer periphery of the tail plug 9 There are annular fitting protrusions (9a, 9b, 9c than those located on the opening end side of the coating liquid storage chamber 2) that are locked over the side protrusions and compressed in the coating liquid storage chamber 2 The tail plug 9 is prevented from coming off due to gas pressure. The fitting protrusions 9a, 9b and 9c of the tail plug 9 have a longitudinal cross-sectional shape, and the inclined surface on the front side in the insertion direction has a relatively gentle inclination, and the inclined surface on the rear side in the insertion direction has an inclined angle. . This facilitates assembling by making the resistance when moving over the fitting protrusion relatively small when joining the tail plug 9 to the coating liquid storage chamber 2, and the fitted tail plug 9 is resistant to compressed gas. This is to make it difficult to come out even if it is applied. Further, a hook 9g is formed on the tail plug 9 so that there is no play with the coating liquid storage chamber 2 at the position where the tail plug 9 is fitted, and after the over fitting is completed, the rear of the coating liquid storage chamber 2 is formed. The flange 9g and the fitting inner protrusions 9a, 9b, 9c are in contact with the end opening edge, and the rear edge opening edge of the coating liquid storage chamber 2 and the fitting inner protrusions 2a, 2b, 2c It is supposed to be sandwiched between.

  From the minimum inner diameter of the fitting inner protrusions 2a, 2b, 2c, further inward (downward in the drawing, application side) than the fitting inner protrusion 2c formed on the innermost side of the coating liquid storage chamber 2. Is formed as a peripheral surface 2d that forms an airtight seal with the outer peripheral portion located inward of the coating liquid storage chamber 2 from the fitting protrusion 9c of the tail plug 9. Since the circumferential surface 2d is formed as a portion having a smaller diameter than the minimum inner diameter of the fitting inner protrusions 2a, 2b, and 2c, the airtight circumferential portion of the tail plug 9 is inserted when the tail plug 9 is inserted. The possibility of hitting the inner surface of the coating liquid storage chamber 2 is low and scratches are unlikely. Therefore, the risk of impairing the sealing performance in the coating liquid storage chamber 2 can be avoided. The annular fitting inward protrusion of the coating liquid storage chamber 2 and the fitting protrusion of the tail plug 9 are not limited to three, and the tail plug 9 can be prevented from coming off if there is at least one. The reason for providing a plurality is to make the fixing more reliable.

FIG. 3 shows another example. It is a modification of the joining structure of the tail plug 9 and the coating liquid storage chamber 2.
Formed in the outer periphery of the tail plug 9 are two peripheral projections 9d and 9e having a substantially mountain shape so as to be located inward of the coating liquid storage chamber 2 from the fitting projection 9c of the tail plug 9. ing. When the apexes of the circumferential projections 9d and 9e are linearly pressed against the inner wall of the coating liquid storage chamber 2, pressure is concentrated on the apexes. As the area is small, the desired sealing performance can be obtained without increasing the contact force, so that the assembly can be facilitated.
If the circumferential projection for sealing the tail plug 9 is at least one, the compressed gas in the coating liquid storage chamber 2 can be surely sealed. The reason for providing a plurality is to make the sealing property more reliable.

Vertical section showing an example Part I enlarged vertical sectional view of FIG. Main part enlarged vertical sectional view showing another example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Correction liquid 2 Coating liquid storage chamber 2a, 2b, 2c Fitting inward protrusion 2d Circumferential contact surface 3 Ball 4 Ball holder 5 Coil spring 6 Followers 7 Floating body 8 Gas 9 Tail plug 9a, 9b, 9c Fitting protrusion 9d 9e Circumferential protrusion 9f Gas inlet 9g Gutter 10 Cap

Claims (2)

The application liquid storage chamber of the applicator that seals in a compressed state the gas that supports discharge of the application liquid by pressure together with the application liquid, and the joint at the cylindrical opening of the application liquid storage chamber become airtight. And a fitting projection that crosses over the joint of both members to form a fitting projection, and is airtight at an inner position of the coating liquid storage chamber than the fitting projection. The joining structure of the member in the applicator which has arrange | positioned the sealing contact part. The joining structure according to claim 1, wherein the maximum outer diameter of the hermetic sealing contact portion of the member attached to the opening of the coating liquid storage chamber is smaller than the minimum inner diameter of the opening of the coating liquid storage chamber.