Writing instrument

Abstract

To provide a writing instrument which can suppress the generation of abnormal noise and can provide a soft writing feel.SOLUTION: Provided is a writing instrument 1 in which a pen body 3 is press-fitted and fixed to the inner surface of a front end opening 21 of a barrel 2, the front end of the pen body 3 protruding forward from the front end of the barrel 2. A pen body fixing portion 22 is provided for press-fitting and fixing the outer surface of the pen body 3 to the inner surface of the front end opening 21 of the barrel 2, the pen body fixing portion 22 having a weak fixing portion 221 and a strong fixing portion 222, the fixing force between the weak fixing portion 221 and the pen body 3 being weaker than the fixing force between the strong fixing portion 222 and the pen body 3, the weak fixing portion 221 being positioned axially forward of the strong fixing portion 222.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a writing instrument, and more particularly to a writing instrument having a pen tip and an ink occlusion body. [Background technology]

[0002] Patent document 1 discloses a writing instrument in which a pen body made of a fiber-processed or porous material is press-fitted and fixed to the inner surface of the front end opening of the barrel, with the front end of the pen body protruding forward from the front end of the barrel, and which is capable of suppressing the generation of abnormal noise when applying ink even if the outer diameter of the pen body is made thin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-274626 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology disclosed in Patent Document 1 has a structure that requires the pen body to be firmly gripped in order to suppress the generation of abnormal noise during application, which prevents the pen body from bending when writing, making it impossible to achieve a soft writing feel.

[0005] The present invention is intended to solve the above-mentioned problems of the prior art, and aims to provide a writing implement that can suppress the generation of abnormal noise and provide a soft writing feel. [Means for solving the problem]

[0006] The first invention of the present application is a writing instrument in which a pen body is press-fitted and fixed to the inner surface of the front end opening of a barrel, and the front end of the pen body protrudes forward from the front end of the barrel, and a pen body fixing portion is provided on the inner surface of the front end opening of the barrel to press-fit the outer surface of the pen body, the pen body fixing portion has a weak fixing portion and a strong fixing portion, the fixing force between the weak fixing portion and the pen body is weaker than the fixing force between the strong fixing portion and the pen body, and the weak fixing portion is positioned axially forward of the strong fixing portion.

[0007] The writing instrument of the first invention has a pen body fixing portion, which has a weak fixing portion and a strong fixing portion, and the fixing force between the weak fixing portion and the pen body is weaker than the fixing force between the strong fixing portion and the pen body. Furthermore, the weak fixing portion is located further forward in the axial direction than the strong fixing portion. This allows the strong fixing portion to firmly fix the pen body. Furthermore, because the weak fixing portion fixes the pen body weakly further forward in the axial direction than the strong fixing portion, the pen body can bend while suppressing the generation of abnormal noise, making it possible to obtain a soft writing feel.

[0008] The second invention of the present application requires that, in the writing instrument of the first invention, the sum of the contact lengths between the weakly adhered portion and the pen body in any cross-section of the weakly adhered portion is smaller than the sum of the contact lengths between the strongly adhered portion and the pen body in any cross-section of the strongly adhered portion.

[0009] In the writing implement of the second invention, the sum of the contact lengths between the weakly adhered portions and the pen body in any cross section of the weakly adhered portions is smaller than the sum of the contact lengths between the strongly adhered portions and the pen body in any cross section of the strongly adhered portions. This makes it easier to weaken the adhesion between the weakly adhered portions and the pen body than the adhesion between the strongly adhered portions and the pen body, making it easier to achieve a soft writing feel while suppressing the generation of abnormal noise.

[0010] The third invention of the present application is a writing instrument according to the second invention, wherein the pen body fixing portion is a plurality of ribs that protrude radially inward, extend in the axial direction, and are arranged at equal intervals circumferentially, and the number of ribs in the weak fixing portion is less than the number of ribs in the strong fixing portion.

[0011] In the writing instrument of the third invention, the pen body attachment portion is composed of multiple ribs, and the number of ribs in the weakly attached portion is fewer than the number of ribs in the strongly attached portion. When the contact length per rib in the weakly attached portion is the same as the contact length per rib in the strongly attached portion, the number of ribs becomes a factor (component) of the total contact length. Therefore, by making the number of ribs in the weakly attached portion less than the number of ribs in the strongly attached portion, it is possible to make the total contact length between the weakly attached portion and the pen body in any cross-section of the weakly attached portion smaller than the total contact length between the strongly attached portion and the pen body in any cross-section of the strongly attached portion. This makes it easier to achieve a soft writing feel while suppressing the generation of abnormal noise.

[0012] The fourth invention of the present application is a writing instrument according to the third invention, in which the rib of the weakly fixed portion is located at the same circumferential position as the rib of the strongly fixed portion and is integrally connected to the rib of the strongly fixed portion in the axial direction.

[0013] In the writing implement of the fourth invention, the ribs of the weakly attached portion are located at the same circumferential position as the ribs of the strongly attached portion, and the ribs of the weakly attached portion are integrally connected to the ribs of the strongly attached portion forward in the axial direction. This makes it possible to easily manufacture a barrel that can provide a soft writing feel while suppressing the generation of abnormal noise.

[0014] The fifth invention of the present application is a writing instrument according to the second invention, wherein the pen body fixing portion is a plurality of ribs that protrude radially inward, extend axially, and are arranged at equal intervals circumferentially, the ribs of the weak fixing portion are integrally connected to the ribs of the strong fixing portion in the axial direction, and the circumferential width of the front end of the weak fixing portion is narrower than the circumferential width of the rear end of the strong fixing portion.

[0015] In the writing implement of the fifth invention, the pen body fixing portion is a plurality of ribs, and the ribs of the weak fixing portion are integrally connected to the ribs of the strong fixing portion forward in the axial direction. In other words, the number of ribs of the weak fixing portion and the number of ribs of the strong fixing portion are the same, and the front of the ribs of the pen body fixing portion is the weak fixing portion, and the rear of the pen body fixing portion is the strong fixing portion. When the number of ribs of the weak fixing portion and the strong fixing portion are the same, The contact length per rib is a factor (element) of the contact length. Therefore, by making the width of the rib in the weakly adhered portion narrower than the width of the rib in the strongly adhered portion, it is possible to make the total contact length between the weakly adhered portion and the pen element in the cross section of the weakly adhered portion smaller than the total contact length between the strongly adhered portion and the pen element in the cross section of the strongly adhered portion. This makes it easier to obtain a soft writing feel while suppressing the generation of abnormal noise. [Effects of the Invention]

[0016] The present invention provides a writing implement that can suppress the generation of abnormal noise and provide a soft writing feel. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a front view of a writing instrument according to a first embodiment of the present invention. [Figure 2] 1 is an enlarged vertical cross-sectional view of a main part of a first embodiment of the present invention. [Figure 3] 1 is an enlarged longitudinal cross-sectional view of a main portion of a barrel according to a first embodiment of the present invention. [Figure 4] 1 is a cross-sectional perspective view of a barrel according to a first embodiment of the present invention; [Figure 5] 4A and 4B are cross-sectional views of a barrel according to a first embodiment of the present invention, taken along line AA in FIG. 3, and FIG. 4B is a cross-sectional view of a barrel according to a first embodiment of the present invention, taken along line BB in FIG. [Figure 6] FIG. 6 is an enlarged longitudinal cross-sectional view of a main portion of a barrel according to a second embodiment of the present invention. [Figure 7] FIG. 10 is a cross-sectional perspective view of a barrel according to a second embodiment of the present invention. [Figure 8]7A is a cross-sectional view taken along line CC in FIG. 6, and FIG. 7B is a cross-sectional view taken along line DD in FIG. 6, of a barrel according to a second embodiment of the present invention. [Figure 9] FIG. 10 is an enlarged longitudinal cross-sectional view of a main portion of another example of the barrel according to the second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] The definitions of directions and the like used in this embodiment will be described below. In the writing instrument 1, the direction in which the axis (central axis or axial line) of the barrel 2 extends is referred to as the axial direction or axial direction. In this embodiment, the central axis of the pen body 3 is coaxial with the central axis of the barrel 2. The direction perpendicular to the axial direction is referred to as the radial direction, and the direction along the circumference around the axis is referred to as the circumferential direction. Furthermore, the side from which the pen body 3 protrudes (the top side of the paper in Figure 2) is referred to as the front or top, and the side opposite the pen body 3 (the bottom side of the paper in Figure 2) is referred to as the rear or bottom. Accordingly, the direction parallel to the axial direction is sometimes referred to as the front-to-back direction.

[0019] First Embodiment A first embodiment of the present invention is shown in Figures 1 to 5. A writing instrument 1 of this embodiment has a pen body 3, an ink occlusion body 4, and a barrel 2.

[0020] Pen type 3 The pen body 3 of this embodiment is substantially cylindrical, and the front end of the pen body 3 is ground into a bullet shape, i.e., a bullet shape. Other shapes include a chisel shape, a square pillar shape, and a plate shape, and any shape may be used depending on the purpose.

[0021] The pen body 3 is made of synthetic resin fibers (such as polyester fibers, acrylic fibers, nylon fibers, etc.). In addition to these, the pen body 3 may be made of any material as long as it allows ink to flow through it, and specific examples include felt, a writing brush, a porous synthetic resin material with open cells, and a plastic pen body with capillary passages in the axial direction.

[0022] The pen body 3 has a writing part 31 at the front of the pen body 3 that comes into contact with the writing surface and applies ink. The pen body 3 also has an engaged part 32 at the middle of the pen body 3 that engages with the barrel 2, which will be described later. The pen body 3 has a connecting part 33 at the rear that is connected in a piercing manner to the ink occlusion body 4, which will be described later. The outer peripheral surface of the rear end of the connecting part 33 may be tapered to make it easier to pierce the ink occlusion body 4.

[0023] Ink absorbing material 4 The ink occlusion body 4 may be a substantially cylindrical body made of a material having continuous pores that can be impregnated with ink, and examples thereof include heat-sealed fiber bundles, resin-processed fiber bundles, resin-processed felt, needle-punched felt, porous open-cell synthetic resins, etc. The ink occlusion body 4 may also be configured to have an outer skin made of a rigid resin film or the like on its outer periphery. In this embodiment, one ink occluder 4 is provided inside the barrel 2, but a configuration may also be used in which a plurality of ink occluders 4 of different thicknesses and shapes are provided. The rear end of the pen body 3 is inserted into the axial center of the front end surface of the ink occluder 4, and the rear end of the pen body 3 is positioned inside the front of the ink occluder 4.

[0024] The ink stored in the ink storage body 4 and discharged from the pen tip may be, for example, an oil-based or water-based writing liquid for a marking pen or a whiteboard.

[0025] ·Shaft cylinder 2 The barrel 2 is generally cylindrical and houses an ink occlusion body 4 inside. The pen body 3 is press-fitted and fixed into the barrel 2 with the writing part 31 at the front of the pen body 3 protruding. The writing instrument 1 of the present invention is a double-ended writing instrument in which pen bodies 3 of different shapes protrude from both ends of the barrel 2, as shown in Figure 1. However, the present invention is not limited to this, and may also be a single-ended writing instrument. Caps may also be provided on both ends of the barrel 2 to prevent ink from evaporating from the pen tip.

[0026] The material of the barrel 2 may be resin, particularly polycarbonate or polypropylene, from the viewpoint of cost efficiency, or wood or metal (e.g., stainless steel) from the viewpoint of appearance. The barrel 2 may be composed of two or more cylindrical bodies from the viewpoint of assembling ease. In this embodiment, the barrel 2 is composed of two parts from the viewpoint of assembling ease.

[0027] An opening 21 that opens forward is provided at the front end of the barrel 2. The pen body 3 protrudes from this opening 21. A pen body fixing portion 22 is provided on the inner surface of the opening 21, to which the engaged portion 32 of the pen body 3 is press-fitted and fixed. An ink occlusion body storage portion 24 that stores the ink occlusion body 4 is provided inside the barrel 2, further rearward of the pen body fixing portion 22.

[0028] The pen body fixing portion 22 has a weak fixing portion 221 and a strong fixing portion 222. The weak fixing portion 221 is arranged further forward than the strong fixing portion 222. In other words, the weak fixing portion 221 is arranged closer to the open end of the barrel 2 than the strong fixing portion 222. The fixing force between the weak fixing portion 221 and the pen body 3 is weaker than the fixing force between the strong fixing portion 222 and the pen body 3. As a result, the strong fixing portion 222 firmly fixes the rear side of the engaged portion 32 of the pen body 3. Furthermore, the weak fixing portion 221 fixes the pen body 3 axially forward of the strong fixing portion 222 and with a weaker fixing force than the strong fixing portion 222. In other words, the weak fixing portion 221 fixes the front side of the engaged portion 32 of the pen body 3 with a weaker fixing force than the strong fixing portion 222. This allows the pen element 3 to bend, making it possible to obtain a soft writing feel.

[0029] There are several configurations that can weaken the adhesive force between the weakly adhered portion 221 and the pen body 3 compared to the adhesive force between the strongly adhered portion 222 and the pen body 3. First, there is a configuration in which the sum of the contact lengths between the weakly adhered portion 221 and the pen body 3 in any cross section is made smaller than the sum of the contact lengths between the strongly adhered portion 222 and the pen body 3 in any cross section. Second, there is a configuration in which the amount of depression of the weakly adhered portion 221 into the pen body 3 in any cross section is made smaller than the amount of depression of the strongly adhered portion 222 into the pen body 3 in any cross section. In this embodiment, a configuration that reduces the contact length was selected. This makes it possible to weaken the adhesive force between the weakly adhered portion 221 and the pen body 3 compared to the adhesive force between the strongly adhered portion 222 and the pen body 3. At this time, the amount of depression of the pen body fixing portion 22 into the pen body 3 can be set within a range that does not pose a risk of excessive damage to the pen body 3, thereby preventing poor ink ejection from the pen body 3 when writing.

[0030] The pen element fixing portion 22 is made up of multiple ribs that protrude radially inward from the inner surface of the barrel 2, extend in the axial direction, and are evenly spaced around the circumference. That is, the weak fixing portion 221 is located behind the open end of the barrel 2, protrudes radially inward from the inner surface of the barrel 2, extends in the axial direction, and is evenly spaced around the circumference. Similarly, the strong fixing portion 222 is located behind the weak fixing portion 221, protrudes radially inward from the inner surface of the barrel 2, extends in the axial direction, and is evenly spaced around the circumference. The ribs of the weak fixing portion 221 and the strong fixing portion 222 are evenly spaced around the circumference, which allows the pen element 3 to be fixed evenly around the circumference. This is preferable because it eliminates the risk of writing differences depending on the circumferential orientation of the writing instrument 1.

[0031] The maximum protrusion amount of each rib of the weakly fixed portion 221 that protrudes radially inward from the inner surface of the barrel 2 may differ between the ribs of the weakly fixed portion 221, but it is preferable that they are the same. This is because the pen body 3 can be fixed evenly in the circumferential direction, and there is no risk of differences in writing due to the circumferential orientation of the writing instrument 1. For the same reason, the maximum protrusion amount of each rib of the strongly fixed portion 222 may differ between the ribs of the strongly fixed portion 222, but it is preferable that they are the same.

[0032] It is preferable that the maximum radially inward protrusion of the rib of the weakly bonded portion 221 is the same as the maximum radially inward protrusion of the rib of the strongly bonded portion 222. This is because there is no difference in thickness between the weakly bonded portion 221 and the strongly bonded portion 222 in the molded product, which eliminates the risk of poor appearance such as sink marks. Furthermore, the maximum radially inward protrusion of the rib of the weakly bonded portion 221 and the strongly bonded portion 222 can be set within a range that does not excessively damage the pen element 3, thereby preventing poor ink ejection from the pen element 3 during writing. However, the radially inner circumferential surface of the rib may have a draft angle of the mold, so that the maximum radially inward protrusion of the rib of the weakly bonded portion 221 is slightly different from the maximum radially inward protrusion of the rib of the strongly bonded portion 222. To explain in detail in accordance with this embodiment, the radially inner circumferential surface of the rib of the weakly bonded portion 221 may have a slight gradient such that the maximum protrusion of the rib gradually decreases forward in the axial direction. Similarly, the radially inner peripheral surface of the rib of the strong fixing portion 222 may have a slight gradient such that the maximum protrusion amount of the rib gradually decreases forward in the axial direction.

[0033] In the barrel 2 of this embodiment, the circumferential width of the ribs of the weakly fixed portion 221 and the strongly fixed portion 222 is constant along the axial direction, and the circumferential width of the ribs of the weakly fixed portion 221 and the strongly fixed portion 222 are the same. In other words, the shapes of the ribs of the weakly fixed portion 221 and the strongly fixed portion 222 are the same. That is, the contact length with the pen element 3 per rib of the weakly fixed portion 221 in any cross section is the same as the contact length with the pen element 3 per rib of the strongly fixed portion 222 in any cross section. In this case, the number of ribs is a factor (component) of the total contact length. Therefore, by making the number of ribs in the weakly adhered portion 221 less than the number of ribs in the strongly adhered portion 222, it is possible to make the total contact length between the weakly adhered portion 221 and the pen body 3 in any cross section of the weakly adhered portion 221 less than the total contact length between the strongly adhered portion 222 and the pen body 3 in any cross section of the strongly adhered portion 222. This makes it easier to obtain a soft writing feel while suppressing the generation of abnormal noise.

[0034] In this embodiment, as shown in Figures 3 and 5, the weakly fixed portion 221 has three ribs, and the ribs of the weakly fixed portion 221 are arranged at equal intervals of 120° in the circumferential direction. Each rib has, for example, a width of approximately 0.5 mm, a radial height of approximately 0.35 mm, and an axial length of approximately 1 mm. In any cross section, the contact length per rib is approximately 0.53 mm, and the total contact length of the weakly fixed portion 221 is approximately 1.59 mm. In this embodiment, the weakly fixed portion 221 is arranged between a and b in Figure 3.

[0035] In this embodiment, as shown in Figures 3 and 5, the strongly fixed portion 222 has six ribs, which are arranged at equal intervals of 60° around the circumference. Each rib has a width of approximately 0.5 mm, a radial height of approximately 0.35 mm, and an axial length of approximately 4.5 mm. In any cross section, the contact length per rib is approximately 0.53 mm, and the total contact length of the strongly fixed portion 222 is 3.18 mm. In this embodiment, the strongly fixed portion 222 is arranged between bc in Figure 3.

[0036] The ribs of the weakly fixed portion 221 and the ribs of the strongly fixed portion 222 may be arranged at different positions in the circumferential direction, but from the viewpoint of formability, it is preferable that they be arranged at the same position in the circumferential direction. Furthermore, from the viewpoint of formability and the strength of the ribs of the pen body fixing portion 22, it is preferable that the ribs of the weakly fixed portion 221 be integrally connected to one of the ribs of the strongly fixed portion 222 in the axial direction. In other words, a long rib consisting of the ribs of the weakly fixed portion 221 and the ribs of the strongly fixed portion 222, and a short rib consisting only of the ribs of the strongly fixed portion 222 are arranged inside the barrel 2.

[0037] In order for the ribs of the weakly fixed portion 221 to be integrally connected in the axial direction with any of the ribs of the strongly fixed portion 222, it is preferable that the number of ribs of the strongly fixed portion 222 be an integer multiple of the number of ribs of the weakly fixed portion 221. This allows the ribs of the weakly fixed portion 221 and the ribs of the strongly fixed portion 222 to be arranged at equal intervals in the circumferential direction, and also allows the ribs of the weakly fixed portion 221 and the ribs of the strongly fixed portion 222 to be integrally connected in the axial direction. In this embodiment, the weakly fixed portion 221 has three ribs, and the strongly fixed portion 222 has six ribs, which is twice the number of ribs of the weakly fixed portion 221. In this case, the ribs of the weakly fixed portion 221 are arranged at 120° intervals in the circumferential direction, and the ribs of the strongly fixed portion 222 are arranged at 60° intervals in the circumferential direction. That is, long ribs formed by integrally connecting the ribs of the weakly fixed portions 221 and the ribs of the strongly fixed portions 222 are arranged at 120° intervals in the circumferential direction, and short ribs consisting only of the ribs of the strongly fixed portions 222 are arranged at positions 60° circumferentially offset from the long ribs. In other words, the long ribs consisting of the ribs of the weakly fixed portions 221 and the ribs of the strongly fixed portions 222 and the short ribs consisting only of the ribs of the strongly fixed portions 222 are arranged alternately in the circumferential direction.

[0038] In this embodiment, the pen body is provided with a locking portion 23 that is connected to the rear of the pen body fixing portion 22 (rib) and protrudes radially inward beyond the pen body fixing portion 22. The rear end face of the engaged portion 32 of the pen body 3 abuts against the front end face of the locking portion 23, preventing the pen body 3 from sinking behind the barrel 2 and restricting displacement of the pen body 3 in the front-to-rear direction. The radial inner surface of the locking portion 23 may come into contact with the pen body 3, but even if it does not come into contact, this does not affect writing performance.

[0039] The writing instrument 1 of this embodiment is a writing instrument 1 in which a pen body 3 is press-fitted and fixed to the inner surface of a front end opening 21 of a barrel 2, and the front end of the pen body 3 protrudes forward from the front end of the barrel 2, and a pen body fixing portion 22 is provided to press-fit the outer surface of the pen body 3 to the inner surface of the front end opening 21 of the barrel 2, and the pen body fixing portion 22 has a weak fixing portion 221 and a strong fixing portion 222, and the fixing force between the weak fixing portion 221 and the pen body 3 is weaker than the fixing force between the strong fixing portion 222 and the pen body 3, and the weak fixing portion 221 is positioned axially forward of the strong fixing portion 222. That is, the writing instrument 1 of this embodiment is provided with a pen body fixing portion 22, which has a weak fixing portion 221 and a strong fixing portion 222, and the fixing force between the weak fixing portion 221 and the pen body 3 is weaker than the fixing force between the strong fixing portion 222 and the pen body 3. Furthermore, the weak fixing portion 221 is positioned further forward in the axial direction than the strong fixing portion 222. This allows the strong fixing portion 222 to firmly fix the pen body 3. Furthermore, because the weak fixing portion 221 weakly fixes the pen body 3 further forward in the axial direction than the strong fixing portion 222, the pen body 3 can bend while suppressing the generation of abnormal noise, making it possible to obtain a soft writing feel.

[0040] In the writing instrument 1 of this embodiment, the sum of the contact lengths between the weakly adhered portion 221 and the pen body 3 in any cross section of the weakly adhered portion 221 is smaller than the sum of the contact lengths between the strongly adhered portion 222 and the pen body 3 in any cross section of the strongly adhered portion 222. In the writing instrument 1 of this embodiment, the sum of the contact lengths between the weakly adhered portion 221 and the pen body 3 in any cross section of the weakly adhered portion 221 is smaller than the sum of the contact lengths between the strongly adhered portion 222 and the pen body 3 in any cross section of the strongly adhered portion 222. This makes it possible to easily weaken the adhesion force between the weakly adhered portion 221 and the pen body 3 compared to the adhesion force between the strongly adhered portion 222 and the pen body 3, making it easier to obtain a soft writing feel while suppressing the generation of abnormal noise.

[0041] In the writing instrument 1 of this embodiment, the pen element fixing portion 22 is a plurality of ribs that protrude radially inward, extend in the axial direction, and are arranged at equal intervals in the circumferential direction, and the number of ribs in the weakly fixed portion 221 is fewer than the number of ribs in the strongly fixed portion 222. In the writing instrument 1 of this embodiment, the pen element fixing portion 22 is a plurality of ribs, and the number of ribs in the weakly fixed portion 221 is fewer than the number of ribs in the strongly fixed portion 222. When the contact length per rib in the weakly fixed portion 221 is the same as the contact length per rib in the strongly fixed portion 222, the number of ribs becomes a factor (component) of the total contact length. Therefore, by making the number of ribs in the weakly adhered portion 221 less than the number of ribs in the strongly adhered portion 222, it is possible to make the total contact length between the weakly adhered portion 221 and the pen body 3 in any cross section of the weakly adhered portion 221 less than the total contact length between the strongly adhered portion 222 and the pen body 3 in any cross section of the strongly adhered portion 222. This makes it easier to obtain a soft writing feel while suppressing the generation of abnormal noise.

[0042] In the writing instrument 1 of this embodiment, the ribs of the weakly fixed portion 221 are located at the same circumferential position as the ribs of the strongly fixed portion 222, and are integrally connected to the ribs of the strongly fixed portion 222 in the axial direction. In the writing instrument 1 of this embodiment, the ribs of the weakly fixed portion 221 are located at the same circumferential position as the ribs of the strongly fixed portion 222, and are integrally connected to the ribs of the weakly fixed portion 221 forward in the axial direction with the ribs of the strongly fixed portion 222. This makes it possible to easily manufacture a barrel 2 that can provide a soft writing feel while suppressing the generation of abnormal noise.

[0043] <Second embodiment> 6 to 9 show a second form of barrel 2 used in writing instrument 1 according to a second embodiment of the present invention. The pen body 3 and ink occlusion body 4 have the same structures as those in the first embodiment, and therefore detailed explanations will be omitted. Furthermore, with regard to barrel 2, parts that can be configured in the same way as in the above-described embodiment will be given the same reference numerals as those used in the corresponding parts in the above-described embodiment, and duplicate explanations will be omitted.

[0044] ·Shaft cylinder 2 The barrel 2 is of a generally cylindrical shape and accommodates an ink occlusion body 4 inside the barrel 2. The pen body 3 is press-fitted and fixed into the barrel 2 with the writing portion 31 at the front of the pen body 3 protruding. An opening 21 that opens forward is provided at the front end of the barrel 2. The pen body 3 protrudes from this opening 21. A pen body fixing portion 22 is provided on the inner surface of the opening 21, into which the engaged portion 32 of the pen body 3 is press-fitted and fixed. An ink occlusion body accommodation portion 24 that accommodates the ink occlusion body 4 is provided inside the barrel 2, further rearward of the pen body fixing portion 22.

[0045] The pen element fixing portion 22 is made up of multiple ribs that protrude radially inward from the inner surface of the barrel 2, extend in the axial direction, and are evenly spaced around the circumference. That is, the weak fixing portion 221 is located behind the open end of the barrel 2, protrudes radially inward from the inner surface of the barrel 2, extends in the axial direction, and is evenly spaced around the circumference. Similarly, the strong fixing portion 222 is located behind the weak fixing portion 221, protrudes radially inward from the inner surface of the barrel 2, extends in the axial direction, and is evenly spaced around the circumference. The ribs of the weak fixing portion 221 and the strong fixing portion 222 are evenly spaced around the circumference, which allows the pen element 3 to be fixed evenly around the circumference. This is preferable because it eliminates the risk of writing differences depending on the circumferential orientation of the writing instrument 1.

[0046] The maximum protrusion amount of each rib of the weakly fixed portion 221 that protrudes radially inward from the inner surface of the barrel 2 may differ between the ribs of the weakly fixed portion 221, but it is preferable that they are the same. This is because the pen body 3 can be fixed evenly in the circumferential direction, and there is no risk of differences in writing due to the circumferential orientation of the writing instrument 1. For the same reason, the maximum protrusion amount of each rib of the strongly fixed portion 222 may differ between the ribs of the strongly fixed portion 222, but it is preferable that they are the same.

[0047] It is preferable that the maximum radially inward protrusion of the rib of the weakly bonded portion 221 is the same as the maximum radially inward protrusion of the rib of the strongly bonded portion 222. This is because there is no difference in thickness between the weakly bonded portion 221 and the strongly bonded portion 222 in the molded product, which eliminates the risk of poor appearance such as sink marks. Furthermore, the maximum radially inward protrusion of the rib of the weakly bonded portion 221 and the strongly bonded portion 222 can be set within a range that does not excessively damage the pen element 3, thereby preventing poor ink ejection from the pen element 3 during writing. However, the radially inner circumferential surface of the rib may have a draft angle of the mold, so that the maximum radially inward protrusion of the rib of the weakly bonded portion 221 is slightly different from the maximum radially inward protrusion of the rib of the strongly bonded portion 222. To explain in detail in accordance with this embodiment, the radially inner circumferential surface of the rib of the weakly bonded portion 221 may have a slight gradient such that the maximum protrusion of the rib gradually decreases forward in the axial direction. Similarly, the radially inner peripheral surface of the rib of the strong fixing portion 222 may have a slight gradient such that the maximum protrusion amount of the rib gradually decreases forward in the axial direction.

[0048] The ribs of the weakly fixed portion 221 and the ribs of the strongly fixed portion 222 are arranged at the same position in the circumferential direction. Furthermore, the ribs of the weakly fixed portion 221 are integrally connected to the ribs of the strongly fixed portion 222 in the axial direction. In other words, the number of ribs of the weakly fixed portion 221 and the number of ribs of the strongly fixed portion 222 are the same, and the weakly fixed portion 221 is in front of the ribs of the pen body fixing portion 22, and the strongly fixed portion 222 is behind the pen body fixing portion 22. When the number of ribs of the weakly fixed portion 221 and the strongly fixed portion 222 is the same, the contact length with the pen body 3 per rib in any cross section becomes a factor (component) of the contact length. Furthermore, for the reasons mentioned above, in this embodiment, the ribs of the weakly adhered portion 221 and the ribs of the strongly adhered portion 222 are configured to have the same maximum radially inward protrusion, so by making the width of the ribs of the weakly adhered portion 221 narrower than the width of the ribs of the strongly adhered portion 222, it is possible to make the total contact length between the weakly adhered portion 221 and the pen body 3 in any cross section of the weakly adhered portion 221 smaller than the total contact length between the strongly adhered portion 222 and the pen body 3 in any cross section of the strongly adhered portion 222. This makes it easier to obtain a soft writing feel while suppressing the generation of abnormal noise.

[0049] The rib of the pen body fixing portion 22 has a pair of opposing side surfaces in the circumferential direction, and the distance between the side surfaces is referred to as the circumferential width. In the barrel 2 of this embodiment, the circumferential width of the rib of the weak fixing portion 221 and the circumferential width of the rib of the strong fixing portion 222 are constant along the axial direction, and the width of the rib of the weak fixing portion 221 is narrower than the width of the rib of the strong fixing portion 222 (see FIG. 6). In this case, the connection portion between the weak fixing portion 221 and the strong fixing portion 222 may have a surface perpendicular to the axial direction, or may have a smoothly sloping surface that narrows toward the front in the axial direction.

[0050] The opposing side surfaces of the rib of the pen element fixing portion 22 may be configured to have a gradient such that the distance between the side surfaces decreases toward the front in the axial direction (FIG. 9). In other words, the circumferential width of the rib of the pen element fixing portion 22 may be configured to narrow toward the front in the axial direction. In this case, the gradient between the side surfaces of the weak fixing portion 221 and the gradient between the side surfaces of the strong fixing portion 222 may be a single gradient, or multiple gradients may be combined. Furthermore, the angle between the side surfaces of the weak fixing portion 221 may be different from the angle between the side surfaces of the strong fixing portion 222, or may be the same.

[0051] In the writing instrument 1 of this embodiment, the pen element fixing portion 22 is a plurality of ribs that protrude radially inward, extend in the axial direction, and are equally spaced circumferentially, and the ribs of the weak fixing portion 221 are integrally connected to the ribs of the strong fixing portion 222 in the axial direction, and the circumferential width of the front end of the weak fixing portion 221 is narrower than the circumferential width of the rear end of the strong fixing portion 222. In the writing instrument 1 of this embodiment, the pen element fixing portion 22 is a plurality of ribs, and the ribs of the weak fixing portion 221 are integrally connected to the ribs of the strong fixing portion 222 forward in the axial direction. In other words, the number of ribs of the weak fixing portion 221 is the same as the number of ribs of the strong fixing portion 222, and the front of the ribs of the pen element fixing portion 22 is the weak fixing portion 221, and the rear of the pen element fixing portion 22 is the strong fixing portion 222. When the number of ribs in the weakly adhered portion 221 and the strongly adhered portion 222 is the same, the contact length per rib is a factor (elementary element) of the contact length. Therefore, by making the width of the rib in the weakly adhered portion 221 narrower than the width of the rib in the strongly adhered portion 222, it is possible to make the total contact length between the weakly adhered portion 221 and the pen element 3 in the cross section of the weakly adhered portion 221 smaller than the total contact length between the strongly adhered portion 222 and the pen element 3 in the cross section of the strongly adhered portion 222. This makes it easier to obtain a soft writing feel while suppressing the generation of abnormal noise. [Explanation of symbols]

[0052] 1 writing implements 2 shaft cylinder 21 Opening 22 Pen body fixing part 221 Weakly fixed part 222 Strongly bonded part 23 Locking part 24 Ink occlusion body storage section 3 Pen type 31 Writing section 32 Engaged part 33 Connection 4. Ink occlusion body

Claims

1. A writing implement in which a pen body is press-fitted and fixed to the inner surface of a front end opening of a barrel, and a front end of the pen body protrudes forward from the front end of the barrel, a pen body fixing portion for press-fitting and fixing the outer surface of the pen body to the inner surface of the front end opening of the barrel; The pen body fixing portion has a weak fixing portion and a strong fixing portion, The adhesive force between the weakly attached portion and the pen body is weaker than the adhesive force between the strongly attached portion and the pen body, and The weakly fixed portion is disposed forward of the strongly fixed portion in the axial direction. A writing instrument characterized by:

2. A writing instrument as described in claim 1, characterized in that the sum of the contact lengths between the weakly adhered portion and the pen body in any cross-section of the weakly adhered portion is smaller than the sum of the contact lengths between the strongly adhered portion and the pen body in any cross-section of the strongly adhered portion.

3. The writing instrument described in claim 2, characterized in that the pen body fixing portion is a plurality of ribs that protrude radially inward, extend axially, and are arranged at equal intervals circumferentially, and the number of ribs in the weak fixing portion is less than the number of ribs in the strong fixing portion.

4. 4. The writing implement according to claim 3, wherein the rib of the weakly fixed portion is located at the same circumferential position as the rib of the strongly fixed portion and is integrally connected to the rib of the strongly fixed portion in the axial direction.

5. The writing instrument described in claim 2, characterized in that the pen body fixing portion is a plurality of ribs that protrude radially inward, extend axially, and are arranged at equal intervals circumferentially, the ribs of the weak fixing portion are integrally connected to the ribs of the strong fixing portion in the axial direction, and the circumferential width of the front end of the weak fixing portion is narrower than the circumferential width of the rear end of the strong fixing portion.

Images