JP3176744B2 - Method of manufacturing ink storage body and molding die thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an ink holding body and a mold for the same, and more particularly, to a method for manufacturing the ink holding body, which is disposed on the front end side of the ink tank so as to be interposed between the tip chip and the ink tank. When the pressure in the tank filled with ink rises, the ink in the tank is temporarily reduced due to the pressure increase (such as an increase in the internal pressure due to the user's body temperature at the time of writing) in order to suppress unnecessary ink leakage from the tip. TECHNICAL FIELD The present invention relates to a method for producing a synthetic resin ink retainer functioning to accumulate ink in a container and a molding die thereof.

[0002]

2. Description of the Related Art Conventionally, this kind of synthetic resin ink retainer has been integrally formed by injection molding. That is, as illustrated in FIG. 7 and FIG.
A large number of ink retaining groove forming portions 32 having a symmetrical shape (substantially semicircular cross section) are provided at appropriate intervals in one direction from 30, 31 toward the mold thickness direction. The mold is composed of a movable mold a1 'and a fixed mold a2' which are provided with an outside air intake groove forming section 33 and an outside air intake and ink flow groove forming section 34, respectively, and which are provided in the axial direction to be connected to each ink retaining groove forming section 32, respectively. It was integrally formed by the mold A '. Conventionally, however, the outside air intake groove forming section 33 and the outside air intake and ink flow groove forming section 34 are provided in parallel (in the same direction) with the mold clamping and the mold opening directions of the movable and fixed molds a1 'and a2'. An outside air intake groove 36 communicating with each ink retaining groove 35 in a range from the front end side where the front end tip of the ink holding body is mounted to the vicinity of the rear end side in contact with the ink in the tank, and near the front end side from the rear end side An outside air intake / ink flow groove 37 communicated with each ink retaining groove 35 is formed on the opposite side of the outside air intake groove 36 to the extent that it reaches.

An outside air intake and ink flow groove 37 provided in the axial direction of the ink storage unit in communication with each ink storage groove from the rear end side of the ink storage body in contact with the ink in the tank is provided with an outside air intake groove 36 provided on the opposite side. For example, the groove width of the outside air intake and ink flow groove is 0.8 mm or less for the groove width of the outside air intake groove of 2 to 3 mm, and the groove width of the outside air intake and ink flow groove is 0.8 mm or less. It is desirable to set the groove width dimension to less than mm. The reason is that if the groove width of the outside air intake and ink flow groove is set to a groove width of 0.8 mm or more, the flow between the ink filled tank and each ink holding groove is increased, and the pressure in the tank is normal. Even when the ink in the tank flows into each ink holding groove through the outside air intake and ink flow groove, the tank temperature is warmed by the user's body temperature during writing and the pressure in the tank actually increases This is because the original ink holding function of the holding body, which temporarily stores the ink in the tank in order to suppress unnecessary ink leakage from the tip chip, is reduced or lost at that time.

Accordingly, in a conventional mold structure, a molding die for forming an outside air intake and ink flow groove having a thickness corresponding to the groove width of the outside air intake and ink flow groove, for example, a groove width of about 0.8 mm, is about 0.8 mm. Since the outside air intake and ink flow groove forming portion having a thickness (thickness) having a thickness (thickness) must be provided by appropriate means such as a direct engraving method or a nesting method (also referred to as a core method), the mold is formed into a movable and a fixed type. There is a disadvantage that it cannot withstand the thermal shock repeatedly received from the melted synthetic resin injected into the cavity formed between both molds for each cycle operation by tightening, causing metal fatigue in a short period of time and severely eroding, Once it is damaged by thermal shock, it breaks quickly and eventually causes mold cracking, and its life is short,
It is extremely difficult and impossible for the mold structure to sufficiently withstand the thermal shock received from the molten synthetic resin.
At the same time, the workability was poor, and there was a problem in mold production.

In this type of ink holding body, it is an important element to improve the holding function that the outside air intake and the width of the ink flow groove are changed according to the type and characteristics of the ink such as viscosity. However, conventionally, considering thermal shock resistance,
Since the thickness of the outside air intake and ink flow groove forming part is 0.8 mm, which is the limit in the mold structure, the outside air intake and ink flow groove having a groove width according to the type of ink viscosity and its characteristics should be set freely. Very difficult. Therefore, there have been many problems in quality in the past, such as inability to manufacture an ink holding body having a holding function corresponding to the type and characteristics of ink such as viscosity.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances as described above, and the groove width of the outside air intake and ink flow groove can be freely set according to the type and characteristics such as the viscosity of the ink. It can be manufactured, and has no problem on the mold structure for thermal shock resistance, etc. It allows the outside air intake and the ink flow groove having the groove width according to the type and characteristics of the ink viscosity, etc. It is still another object of the present invention to provide a method for manufacturing an ink holding body and a mold for the same, which can extend the life.

[0007]

In order to achieve the above object, the present invention provides a method of manufacturing an ink holding body, which comprises guiding an ink from a front end on which a front end tip is mounted to a rear end side in contact with ink in an ink tank. A core insertion hole is provided in the shaft core, and a plurality of ring-shaped ink retaining grooves are provided on the outer side from the front end side to the rear end side at a proper interval in the circumferential direction and continuously provided in the circumferential direction, and The outside air intake groove communicated with each ink retaining groove in the range from the front end side to the vicinity of the rear end side, and each ink retention groove on the opposite side of the outside air intake groove in the range from the rear end side to the vicinity of the front end side. In a method of manufacturing an ink holding body having an external air intake and ink flow groove in communication with an axial direction, a method is provided in which a center of a width of the external air intake groove and a groove width center of the external air intake and ink flow groove is diametrically connected. Divide the ink holder into two parts symmetrically in the axial direction After the hold body has a structure member molded composed, characterized in that the manner configure brought fixation or engagement connection splitting portion comrades Both hold-constituting member.

The above-mentioned mold for the ink holding body has a guide core insertion hole which extends from the front end side where the front end tip is mounted to the rear end side in contact with the ink in the ink tank. On the outer side extending over the end side, there are a number of ring-shaped ink retaining grooves continuously provided in the circumferential direction and at appropriate intervals in the axial direction. Ink having an axial direction and an outside air intake groove communicated with each ink retaining groove on the opposite side of the outside air intake groove from the rear end side to the vicinity of the front end side. In the forming die of the holding body, a holding body configuration in which the ink holding body is axially symmetrically divided into two on a line connecting the center of the groove width of the outside air intake groove and the outside air intake / ink flow groove in the diameter direction. It consists of both movable and fixed molds for molding members, On one type of dynamic or fixed, it provided a large number of ink holding groove forming portions are arranged in parallel at an appropriate space in one direction toward the KataAtsu direction from the mold division plane,
A substantially semicircular concave portion is provided at the center of each ink retaining groove forming portion facing the mold dividing surface, and the ink retaining groove forming portion sandwiching the concave notch is formed on both sides facing the mold dividing surface. Are provided with a substantially L-shaped outside air intake groove forming section and an outside air intake and ink flow groove forming section, respectively, while the other mold separating surface is opposed to the concave notch of each ink retaining groove forming section. In addition to providing a guide core insertion hole forming portion protruding coaxially with a substantially semicircular cross-section, the outside air intake groove forming portion and the outside air intake and ink flow groove forming portion are opposed to the forming portion, and both mold portions are formed at the time of mold clamping. The present invention is characterized in that an external air intake groove forming part and an external air intake / ink flow groove forming part which are adapted and matched to each other are provided.

[0009]

According to the technical means of the first aspect of the present invention, the center of the groove width center between the outside air intake groove and the outside air intake and ink flow groove is divided into two parts on a line connecting in the diameter direction. The axially symmetrical holding body constituent member is molded,
After that, the divided portions of the two holding member components are fixed or engaged to connect the two holding member components. Thereby, the guide core insertion hole is provided in the shaft core, and a number of ring-shaped ink retaining grooves are provided continuously at an appropriate interval in the axial direction on the outer side extending from the front end side to the rear end side at appropriate intervals in the axial direction. And the outside air intake groove communicated with each ink retaining groove in the range from the front end side to the vicinity of the rear end side, and the outside air intake groove in the range from the rear end side to the vicinity of the front end side. It is possible to manufacture an ink holding body having an outside air intake and ink flowing groove communicating with the ink holding groove in the axial direction.

According to the technical means of the present invention, when the movable and fixed molds are clamped and the mold division surfaces of the two molds are aligned, the ink retaining grooves formed in parallel in one direction at appropriate intervals. The two sides except for the central recess are closely contacted to the mating surface of the mating side, and the guide core of the mating mold is inserted across the center of the concave notch of each ink retaining groove forming section. An outside air intake groove in which a wearing hole forming portion is located coaxially, and an outside air intake groove forming portion and an outside air intake / ink flow groove forming portion on both sides of the ink retaining groove forming portion are formed on a mold dividing surface of a mating die. The molding part and the outside air intake / ink flow groove molding part are matched with each other. Thereby, the guide core insertion hole is provided in the shaft core, and a number of ring-shaped ink retaining grooves are provided continuously at an appropriate interval in the axial direction on the outer side extending from the front end side to the rear end side at appropriate intervals in the axial direction. And the outside air intake groove communicated with each ink retaining groove in the range from the front end side to the vicinity of the rear end side, and the outside air intake groove in the range from the rear end side to the vicinity of the front end side. An ink retaining body having an outside air intake and ink flowing groove communicated with the ink retaining groove in the axial direction is placed on a line connecting the groove width center of the outside air intake groove and the outside air intake and ink flowing groove in the diameter direction. A cavity, the so-called cavity, having the same shape as the divided axially symmetric holding member constituting member is formed between the movable and fixed molds.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.
Reference numeral 3 denotes a tip. FIG. 1 shows a state in which the ink reservoir 1 is inserted into the tip of the ink tank 2 and the ink reservoir 1 is inserted.
The tip of the drawing shows a writing implement in which the tip 3 is inserted and assembled, and the ink holding body 1 comes into contact with the ink 4 filled in the ink tank 2 from the tip side where the tip 3 is inserted. A guide core insertion hole 5 is provided on the shaft core, which extends to the end side, and a large number of ring-shaped ink holdings are provided continuously at an appropriate interval in the circumferential direction on the outer side from the front end side to the rear end side. Grooves 7 and communicate with the ink retaining grooves 6 in the range from the front end to the vicinity of the rear end, and the outside air intake in the range from the rear end to the vicinity of the front end. A conventional structure having, in the axial direction, an outside air intake / ink flow groove 8 communicated with each ink retaining groove 6 on the opposite side of the groove 7 is provided. As shown in FIG. 3, this ink retaining body 1 is symmetrical in the axial direction with respect to a line X connecting the center portions of the groove widths 9 and 10 between the outside air intake groove 7 and the outside air intake and ink flow groove 8 in the diameter direction. After each of the pair of holding member constituting members 1a and 1b, which are divided into two, are molded by the molding die A,
It is configured by fixing or engaging and connecting the divided portions 11 and 12 of both the holding member constituting members 1a and 1b.

Each of the retaining members 1a and 1b is an integrally molded product formed by injecting a molten synthetic resin material (hereinafter, referred to as a molten resin) into a cavity in the mold A, ie, a cavity. A semicircular insertion hole forming concave portion 14 is provided at the center of the divided portions 11 and 12 extending from the side to the rear end side.
A large number of ink-retaining groove forming parts arranged at appropriate intervals in the axial direction from the leading end to the trailing end on the outside of the arc
15 are provided, and approximately L is provided on both open portions sandwiching the concave portion 14 facing the divided portions 11 and 12 of the partition walls 16 which partition the ink retaining groove constituting portions 15 at appropriate intervals in the axial direction. -Shaped external air intake groove forming part 17 and external air intake and ink flow groove forming part 18
(See the two-dot chain line in FIGS. 2 and 3).

The outside air intake groove forming section 17 is provided with the ink holding body 1.
For forming outside air intake grooves 7 for taking in outside air into the respective ink retaining grooves 6. For example, when the groove width 9 of the outside air intake grooves 7 is 3 mm, the divided portions of the holding body constituting members 1a and 1b are divided.
The divided portions 11 and 12 are provided on one side open portion of the partition 16 facing the 11 and 12.
It is formed into an approximately L-shape that is lowered one step from 1.5 mm.
On the other hand, the outside air intake / ink flow groove forming section 18 is provided with a tank 2 in which the outside air taken into each ink holding groove 6 of the ink holding body 1 by the outside air intake groove 7 is filled with the ink 4.
So that the ink 4 in the tank 2 is smoothly supplied (replenished) to the tip 3 through the guide core 19, and through the guide core 19 when the internal pressure in the tank 2 increases. The ink 4 in the tank 2 is supplied to each of the ink retaining grooves 6 so that the ink 4 in the tank 2 is not supplied to the tip 3 more than necessary.
Are used to form the outside air intake and ink flow groove 8 which temporarily flows into the ink storage body 1, that is, the ink storage body 1 has an original holding function. For example, the groove width 10 of the outside air intake and ink flow groove 8 is 0.8 mm. In the case, the partitioning part 11, which faces the divisional parts 11, 12 of the retaining body constituent members 1a, 1b,
It is formed into an approximately L-shape that is lowered one step from 12 to 0.4 mm.

Thus, a symmetrical shape is formed in which the center portion of the groove width 9, 10 between the outside air intake groove 7 and the outside air intake and ink flow groove 8 is divided into two in the axial direction on a line X connecting the center portions in the diameter direction. Of the holding member constituting members 1a, 1b forming a pair
12 Retaining body components 1a, 1b with matching
Are fixedly connected to each other by using an adhesive or the like, so that a guide core insertion hole 5 for inserting the guide core 19 is formed in the front-rear direction around the axis, and is fixedly connected to the outside in a ring shape in the circumferential direction. The partition walls 16 are arranged at appropriate intervals in the axial direction, and are separated by an appropriate groove width in the axial direction from the tip end where the tip 3 is inserted to the rear end in contact with the ink 4 in the tank 2. A large number of ring-shaped ink retaining grooves 6 are provided, and the outer peripheral edge of each of the partition walls 16 except for the first rear partition wall 16 in contact with the ink 4 in the tank 2 has a groove width 9 of, for example, about 3 mm. Outside air intake groove 7 formed in communication with each ink retaining groove 6.
Excluding the second partition 16 at the tip end, the outer peripheral edge of the partition 16 opposite to the outside air intake groove 7 is, for example, 0.8 mm.
It is possible to manufacture the ink holding body 1 having the groove width 10 of about the same degree and having the outside air intake and ink flowing groove 8 communicating with each ink holding groove 6 in the axial direction. ).

Accordingly, the divided portions 11 and 12 of the holding member constituting members 1a and 1b forming a pair formed in a symmetrical shape in the axial direction are fixedly joined to each other, so that the holding members 1a and 1b come into contact with the ink 4 in the tank 2 of the ink holding member 1. The outside air intake and ink flow grooves 8 are formed so as to communicate with the ink retaining grooves 6 and extend in the axial direction in a range from the rear end side to the vicinity where the front end into which the tip 3 is inserted is formed. It can be manufactured while freely setting the groove width 10 of the outside air intake and ink flow groove 8 according to the kind and characteristics such as the viscosity of the ink 4.

In the case of the ink storage body 1 of the present embodiment, the outside air intake groove 7 for the first partition (the leftmost side in FIG. 2) 16 at the front end serving as an intake of the outside air to each ink retention groove 6. As shown in FIG. 2, the formation position of the first partition wall 16 located on the extension of the outside air intake and ink flow groove 8 is as shown in FIG.
Outside air taken in from the outside air intake groove 7 provided in the first partition 16 passes through the ink retaining groove 6 formed between the second partition 16 and the outside air. Is configured to be taken into each ink retaining groove 6 while flowing into each outside air intake groove 7 provided so as to be continuous in the axial direction.

Next, a description will be given of a molding die A for molding the above-mentioned holding member constituting members 1a and 1b. The molding die A includes both movable and fixed dies a1 and a2. On the other hand, in the drawing, the movable mold a1 is provided with a large number of ink retaining groove forming portions 21 arranged in parallel in the mold thickness direction from the mold dividing surface 20 and in one direction at appropriate intervals. A substantially semicircular recess 22 is provided at the center of the molding portion 21 facing the mold division surface 20, and the mold separation surface 20 of each ink retaining groove molding portion 21 sandwiching the recess 22 is provided. Are formed on the both sides facing each other, and a substantially L-shaped outside air intake groove forming section 23 and an outside air intake and ink flow groove forming section 24 are provided respectively.

The ink retaining groove forming portions 21 have a thickness corresponding to the groove width of each of the ink retaining grooves 6 from the mold dividing surface 20 of the movable mold a1 in the mold thickness direction, that is, toward the mold rear side. The resin which is provided at a parallel interval in the axial direction of each of the ink retaining grooves 6 and which is injected and filled into the partition wall molding portions 25 having a substantially semicircular cross section formed between the ink retaining groove molding portions 21. The molten metal is solidified to form the partition walls 16 so that the ink retaining grooves 6 are formed between the partition walls 16. And
A substantially semi-circular recess 22 is provided toward the center of each ink retaining groove forming portion 21 facing the mold dividing surface 20 and forward of the ink retaining groove forming portion 21 located on the front end side. Part 22 ...
Each of the ink retaining groove forming portions 21... Sandwiching the outside air intake groove forming portion, which is notched in a substantially L-shape, is formed on both sides facing the mold dividing surface 20.
23 and an outside air intake / ink flow groove forming section 24 are provided.

The outside air intake groove forming part 23 and the outside air intake and ink flow groove forming part 24 are divided into two parts from the center of the outside air intake groove 7 and the outside air intake and ink flow groove 8 in the groove widths 9 and 10 respectively. The concave portion 22 of each of the ink retaining groove forming portions 21... Facing the mold dividing surface 20 of the movable mold a1 in a substantially L-shaped shape.
Cut directly on both sides sandwiching… (by Jikaka method)
It is provided in a plane, and the outside air intake groove forming part 26 and the outside air intake and ink flow groove forming part 27 of the fixed mold a2 which will be described
It is formed so as to conform to each.

A guide core is inserted into the mold dividing surface 28 of the fixed mold a2 so as to face the concave notches 22 of each of the ink retaining groove forming portions 21 so as to protrude coaxially with a substantially semicircular cross section. Hole forming part 29
And an external air intake groove forming part which is opposed to the external air intake groove forming part 23 and the external air intake and ink flow groove forming part 24 so as to be fitted to the two air forming parts 23 and 24 at the time of mold clamping.
26 and an outside air intake / ink flow groove forming part 27 are provided.

The guide core insertion hole forming portion 29 is a mold of the fixed die a2 which faces each of the concave notches 22 of the movable die a1 and is coaxially located along each of the concave notches 22. In the dividing surface 28, each recessed portion 22 having a substantially semicircular cross section is directly cut and provided in a protruding ridge extending in a single line over each other, and when the mold is clamped with the movable mold a1, each recessed portion 22 ... (See FIG. 6).

The outside air intake groove forming section 26 and the outside air intake / ink flow groove forming section 27 are respectively opposed to the outside air intake groove forming section 23 and the outside air intake / ink flow groove forming section 24 of the movable mold a1. It is directly cut and provided on the mold dividing surface 28 of the fixed mold a2, and when the mold is clamped with the movable mold a1, the outside air intake groove forming sections 23 provided on the respective ink retaining groove molding sections 21 of the movable mold a1 and the outside air intake. The ink flow groove forming portions 24 are formed so as to conform to each other (see FIGS. 4 and 6).

According to the molding die A configured as described above, the movable and fixed dies a1 and a2 are clamped to form the dies a1 and a2.
When the mold dividing surfaces 20 and 28 of a2 are combined, the ink retaining groove forming portions 21 provided in the movable mold a1 and arranged in one direction at appropriate intervals are arranged.
.. Are brought into close contact with both sides of the fixed mold a2 except for the recessed portion 22 at the center, and the recessed portions 22 of the ink retaining groove forming portions 21 are mutually centered. Fixed type a2
Is formed coaxially with the guide core insertion hole forming portion 29 of FIG.
FIG. 6). The outside air intake groove forming part 26 and the outside air intake and ink flow groove forming part 27 formed on the mold dividing surface 28 of the fixed mold a2 are formed by the ink retaining groove forming part 21 of the movable mold a1. The guide 23 is fitted to the outside air intake and ink flow groove forming section 24 so that the guide lead insertion hole 5 for inserting the guide lead 19 is formed in the front and rear through the shaft center. A shaft extending from the front end side where the front end tip 3 is inserted to the rear end portion in contact with the ink 4 in the tank 2 by the partition walls 16 which are fixedly connected in a ring shape in the circumferential direction and are present at an appropriate interval in the axial direction. Has a large number of ring-shaped ink retaining grooves 6...
, Except for the first partition 16 which is in contact with the rear end, is formed with a groove width 9 of, for example, about 3 mm, as described above, and takes in outside air which communicates with each ink retaining groove 6. Groove 7
Excluding the second partition 16 at the tip end, the outer peripheral edge of the partition 16 opposite to the outside air intake groove 7 is, for example, 0.8 mm.
The ink holding body 1 formed in the axial direction and having an outside air intake and ink flow groove 8 formed with a groove width of about 10 and communicating with each ink storage groove 6 is connected to the outside air intake groove 7 and the outside air intake and ink flow groove 8. X connecting the center of the groove width 9 and 10 in the diameter direction
Axial symmetrical retaining member 1 divided into two parts above
A cavity having the same shape as a and 1b, a so-called cavity, can be formed between the movable and fixed molds a1 and a2 (see FIGS. 4 to 6).

Accordingly, after clamping the movable and fixed molds a1 and a2, the molten resin is injected between the molds a1 and a2 and solidified, and then the molds a1 and a2 are opened and removed. The axially symmetric holding member constituting members 1a, 1b divided into two on a line x connecting the center portions of the groove widths 9, 10 of the outside air intake groove 7 and the outside air intake / ink flow groove 8 in the diameter direction.
That is, a semicircular insertion hole forming concave portion 14 is provided at the center of the divided portions 11 and 12 extending from the front end side to the rear end side. Partition walls 16 having a large number of ink retaining groove forming portions 15 arranged in parallel at appropriate intervals in the axial direction, and partitioning each ink retaining groove forming portion 15 at appropriate intervals in the axial direction. The opening and closing portions sandwiching the concave portions 22 facing the divided portions 11 and 12 have a substantially L-shaped outside air intake groove forming portion 17 and an outside air taking and ink flowing groove forming portion 18 respectively. The holding member constituting members 1a and 1b can be formed (see the two-dot chain line in FIGS. 2 and 3).

The configuration of the writing implement including the ink holding body 1 is not limited to the configuration shown in FIG. The point is that the ink 4 in the tank 1 is temporarily stopped with the rise of the pressure in order to suppress the unnecessary flow of the ink 4 from the tip 3 when the pressure in the tank 2 filled with the ink 4 rises. It is needless to say that the present invention is directed to all writing instruments configured by incorporating the ink holding body 1 having a function of storing the ink in the ink container. Further, the structure of the mold A is not limited to the single-cavity (single cavity die) shown in FIG. 4, but may be any mold structure such as a multiple-cavity (multicavity die). Generally, multi-cavity is mainly adopted in consideration of productivity.

[0026]

Since the present invention is constructed as described above,
The following effects are obtained. . Divided part of the holding member constituting member which is formed into an axially symmetrical shape which is divided into two along a line X connecting the center portions of the groove widths 9 and 10 of the outside air intake groove and the outside air intake and ink flow groove in the diameter direction. By fixing or engaging the members to connect the two retaining members, the guide core insertion hole is provided in the shaft core, and the shaft is connected to the outer periphery from the front end to the rear end in the circumferential direction. A plurality of ring-shaped ink retaining grooves at appropriate intervals in the direction, and an outside air intake groove communicating with each ink retaining groove in a range from the front end side to the vicinity of the rear end side; and a rear end side to the front end side. It is possible to manufacture an ink holding body having an outside air intake and ink flowing groove communicating with each ink holding groove in the axial direction on the opposite side of the outside air intake groove as far as the vicinity. Therefore, according to the method of manufacturing the ink holding body of the present invention, the groove width 10 of the outside air intake and ink flow groove is reduced by the ink without being restricted by thermal shock resistance or the like as in the conventional mold for forming the ink holding body. It is possible to manufacture and provide an ink retaining body having an outside air intake and ink flow groove having a groove width 10 according to the type and characteristics such as the viscosity of the ink while freely setting according to the type and characteristics such as the viscosity of the ink. it can. . By closing the movable and fixed molds and aligning the mold separation surfaces of both molds, each ink retaining groove molding part that is arranged in parallel in one direction at an appropriate interval has both sides excluding the concave notch at the center. The mating surface is closely contacted with the mating surface of the mating side, and the guiding core insertion hole forming portion of the mating type is located coaxially over the center of the concave portions of the ink retaining groove forming portions. The outside air intake groove forming part and the outside air intake and ink flow groove forming part on both sides of the retaining groove forming part are adapted to the outside air intake groove forming part and the outside air intake and ink flow groove forming part formed on the mold division surface of the partner mold, respectively. The same shape as the axially symmetrical holding member constituting member which is divided into two along a line X connecting the center portions of the groove widths 9 and 10 of the outside air intake groove and the outside air intake and ink flow groove in the diameter direction. To form a cavity, a so-called cavity, between both movable and fixed molds It can be. Therefore, according to the molding die of the ink retaining pair of the present invention, a semicircular insertion hole forming concave portion is provided at the center of the divided portion extending from the front end side to the rear end side, and a semicircle is formed outside the arc of the concave portion. The mold has a large number of ink retaining groove forming portions arranged in parallel at appropriate intervals in the axial direction from the front end side to the rear end side, and a substantially L-shaped opening portion on both sides sandwiching the insertion hole forming concave portion. The ink holding member is provided on a line X connecting the center portions of the groove widths 9 and 10 of the outside air intake groove and the outside air intake and ink flow groove each having the outside air intake groove forming portion and the outside air taking and ink flowing groove forming portion in the diameter direction. Can be formed into an axially symmetric holding member constituting member. That is, the outside air intake and ink flow groove provided in the axial direction by communicating with each ink holding groove from the rear end side of the ink holding body in contact with the ink in the tank has a substantially L-shaped shape in which the groove is divided into two from the center of the groove width. Since it is configured such that it is formed by the outside air intake groove forming part and the outside air intake and ink flow groove forming part which are provided in a plane opposite to the mold dividing surfaces of both the movable and fixed molds, respectively,
It is possible to form an outside air intake and ink flow groove having a groove width 10 according to the type and characteristics of ink viscosity and the like without any problem on the mold structure for thermal shock resistance and the like. To cut the molded part of the movable and fixed molds in two planes without forming the molded part in the movable and fixed mold with the thickness corresponding to the groove width of the intake and ink flow groove. Therefore, the processing can be simplified, and the production cost of the mold can be greatly reduced and the life of the mold can be greatly extended.

[Brief description of the drawings]

FIG. 1 is a main part of a writing implement showing an ink holding body manufactured by the manufacturing method of the present invention inserted and attached to a front end side of an ink tank and a front end tip inserted and attached to the front end of the ink holding body. Enlarged view

FIG. 2 is a side view showing a retaining member.

FIG. 3 is a cross-sectional view showing a state in which divided portions of a pair of holding member constituting members are matched and joined together.

FIG. 4 is a cross-sectional view illustrating a clamped state of a molding die for molding the retaining member.

FIG. 5 is a sectional view taken along the line VV in FIG. 4;

6 is a sectional view taken along the line VI-VI in FIG.

FIG. 7 is a side view showing a conventional molding die.

FIG. 8 is a longitudinal sectional view showing a mold clamping state;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Ink storing body 1a, 1b ... Retaining body constituent member 2 ... Ink tank 3 ... Tip chip 4 ... Ink 5 ... Guide core insertion hole 6 ... Ink storing groove 7 ... External air intake groove 8 ... External air intake and ink flow groove 9 … The groove width of the outside air intake groove 10… the groove width of the outside air intake and ink flow groove 11, 12… the divided part of the holding member constituent member 14… the insertion hole constituent concave part 15… the ink holding groove constituent part 17… the outside air intake groove constituent part 18 ... External air intake and ink flow groove forming part 20 ... Movable mold parting surface 28 ... Fixed die parting surface 21 ... Ink retaining groove forming part 22 ... Recessed part 23,26 ... Outside air intake groove forming part 24,27 … External air intake and ink flow groove forming part 29… Insertion hole forming part

Claims (2)

(57) [Claims] 1. A guide core insertion hole, which passes through a front end side where a front end tip is mounted to a rear end side in contact with ink in an ink tank, is provided on a shaft core. An outside air intake groove which is provided continuously in the circumferential direction, has a number of ring-shaped ink retaining grooves at appropriate intervals in the axial direction, and communicates with each ink retaining groove in a range from the front end side to the vicinity of the rear end side. And an outside air intake and ink flow groove communicating with each ink storage groove on the opposite side of the outside air intake groove from the rear end side to the vicinity of the front end side in the axial direction. Then, a holding member constituting member was formed by dividing the ink holding member into two symmetrically in the axial direction on a line connecting the center portions of the groove widths of the outside air intake groove and the outside air intake / ink flow groove in the diameter direction. Later, the divided portions of the two holding members are fixed or Is a method for manufacturing an ink holding member, wherein the ink holding member is constituted by engaging and connecting. 2. A guide core insertion hole, which extends from a front end side where a front end tip is mounted to a rear end side in contact with ink in an ink tank, is provided on a shaft core, and an outer side extending from the front end side to a rear end side. An outside air intake groove which is provided continuously in the circumferential direction, has a number of ring-shaped ink retaining grooves at appropriate intervals in the axial direction, and communicates with each ink retaining groove in a range from the front end side to the vicinity of the rear end side. And an outside air intake and ink flow groove communicated with each ink storage groove on the opposite side of the outside air intake groove in the range from the rear end side to the vicinity of the front end side. A movable member for forming a holding member constituting member in which the ink holding member is axially symmetrically divided into two on a line connecting the center portions of the groove widths of the outside air intake groove and the outside air intake / ink flow groove in a diametrical direction;・ Made of both fixed and movable types One of the molds is provided with a large number of ink retaining groove forming portions which are arranged in parallel in the mold thickness direction from the mold dividing surface and at appropriate intervals in one direction, and face the mold dividing surface of each ink retaining groove forming portion. A substantially semicircular concave notch is provided at the center, and a substantially L-shaped outside air intake groove forming part and an outside air are formed on both sides of the ink retaining groove forming part sandwiching the concave part facing the mold dividing surface. While providing the intake and ink flow groove forming part respectively,
The other mold is provided with a guide core insertion hole forming portion which is formed in a coaxial shape and has a substantially semicircular cross-section so as to face the recessed portion of each ink retaining groove forming portion. It is characterized in that an external air intake groove forming part and an external air intake and ink flowing groove forming part are provided opposite to the groove forming part and the outside air intake and ink flow groove forming part so as to conform to the two forming parts when clamping the mold. Mold for the ink holder to be used.