JP4594457B2 - Fluid supply valve - Google Patents

Description

【００２１】
第１表から分かるように、ディスク状弁体の大部分を薄くした比較例２のものは、従来品の比較例１のものと反力が同じである。これはディスク状弁体の大部分を薄くした場合、射出成形時に径方向の収縮が大きくなり、結果として反力が小さくならないからである。実施例１〜４のものは、比較例１のものに比べて反力が約３割に低下している。しかし、実施例１及び３のものは収縮時変位量が大きく、また、収縮時変位量の小さい実施例２及び実施例４を比べた場合、実施例４の方が成形後の離型性が良好である。したがって、反力，収縮時変位量及び離型性を考慮すると、実施例１〜４の中では、実施例４が最も良い。
【００２２】
【発明の効果】
本発明の流体供給弁は、特にインクジェット記録装置のインクタンク弁として好適に用いられ、記録時に記録ヘッドから吐出されるインク量に見合ったインクを、インク室から該記録ヘッド部へ良好に供給することができる。
【図面の簡単な説明】
【図１】 インクタンク弁の一例を示す断面図である。
【図２】 上記インクタンク弁に用いられるディスク状弁体の一例を示す部分断面図である。
【図３】 収縮時変位を説明するための屈曲部が設けられたディスク状弁体の一例を示す部分断面形状である。
【図４】 ディスク状弁体の反力を測定するための装置の概略図である。
【図５】 比較例１で作製したディスク状弁体の部分断面図である。
【図６】 比較例２で作製したディスク状弁体の部分断面図である。
【図７】 実施例１で作製したディスク状弁体の部分断面図である。
【図８】 実施例２で作製したディスク状弁体の部分断面図である
【図９】 実施例３で作製したディスク状弁体の部分断面図である。
【図１０】 実施例４で作製したディスク状弁体の部分断面図である。
【符号の説明】
１ ：ディスク状弁体
２ ：硬質材料
３ ：インク（流体）供給孔
４ ：固定弁座
５ ：可動支持体
６ ：バネ
１１：高精度荷重計
１２：プローブ
Ａ ：インク室
Ｂ ：インク供給部
Ｃ ：インクタンク弁[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluid supply valve, and more particularly to an ink tank for satisfactorily supplying ink from an ink chamber to the recording head unit in accordance with the amount of ink discharged from the recording head during recording, particularly in an ink jet recording apparatus. The present invention relates to a fluid supply valve suitable as a valve.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an ink jet recording apparatus is equipped with an ink tank having an ink chamber filled with ink and an ink supply unit that supplies ink to a recording head unit. As a type of the ink tank, for example, ink is supplied to a recording head fixedly attached to the carriage through a tube wound in the apparatus, There are those that are detachable, or those that are integrated with the recording head and detachable from the carriage.
In the former ink tank, ink is supplied by providing a water head difference with respect to the recording head. On the other hand, in the latter, a negative pressure generating source is provided on the ink tank side, so that the recording head is provided. It takes the form of supplying ink.
In recent years, many apparatuses that employ the latter type of ink tank have been proposed in terms of downsizing the apparatus and ease of maintenance.
Such an ink tank is required to satisfactorily supply ink commensurate with the amount of ink ejected from the recording head during recording, and to prevent ink leakage from the ejection port during non-recording.
[0003]
As an ink tank satisfying such a requirement, for example, a cartridge in which a recording head and an ink tank are integrated and detachable from a carriage, the ink tank is filled with an absorber (foam). There is something that is. In this way, by filling the ink tank with the absorber, it is possible to maintain a stable ink meniscus at the ink discharge portion of the recording head, and the ink in the ink tank can be maintained by the capillary force of the absorber. Is retained. In this case, it is necessary that almost the entire ink tank is filled with the absorber, and the capillary force is maintained by holding the ink amount slightly smaller than the maximum amount of ink that the absorber can hold. Is used to generate internal negative pressure. Therefore, even when a mechanical shock such as vibration or a thermal shock such as a temperature change is applied to the recording head and the ink tank, there is little ink leakage from the discharge part of the recording head or the atmosphere communication part of the ink tank. , Stable ink retention can be performed.
[0004]
However, the method in which the entire ink tank is filled with the absorber increases the negative pressure of the absorber as the ink is consumed, resulting in a large amount of ink remaining in the ink tank without being supplied to the recording head. Has the problem of being bad.
In order to solve such a problem, for example, the ink reservoir and the cavity are separated by a wall provided with a through hole in the lower part of the ink tank, and an umbrella check valve is movably provided in the through hole so that the recording head can be moved. There has been proposed an ink cartridge for an ink jet recording head configured to open a valve to discharge ink stored in a tank into a cavity and supply the ink to the recording head when the ink pressure drops (Japanese Patent Laid-Open No. 62). -231759).
According to this, since it is not necessary to store the absorber in the cartridge, it is possible to increase the substantial ink storage capacity in the tank. However, the umbrella check valve is generally used for supplying ink to the recording head. In order to precisely adjust the image quality, there is a big problem that the offset amount is too large and the ink supply amount fluctuates and the print quality is deteriorated.
[0005]
On the other hand, when the umbrella check valve is closed, the ink reservoir and the recording head are completely shut off. Therefore, when the ink in the cavity expands by about 2 to 5% due to a change in the environmental temperature, When the pressure rises, the seal at the connection port with the recording head breaks and the ink leaks, or when it is attached to the recording head, this pressure acts on the recording head as it is, and the recording head and the ink There is a problem in that the negative pressure between the tank and the tank cannot be maintained, and ink leaks from the recording head.
Furthermore, this umbrella check valve responds to the oscillation of the ink caused by the movement of the carriage because the valve closing force is weak at a pressure difference of about several tens of millimeters of water to be maintained in order to stably supply ink to the recording head. There is a problem that the stability of printing is inferior.
[0006]
Therefore, in order to solve the problem of the ink tank equipped with such an umbrella check valve, for example, a pressure difference between the ink chamber and the ink supply unit is provided at a position where the ink chamber and the ink supply unit are divided. Attempts have been made to use an ink tank valve that moves by the above and supplies the ink filled in the ink chamber to the recording head unit.
By mounting such an ink tank valve, it is possible to reliably respond to a minute differential pressure with respect to the recording head, and without being influenced by the oscillation of the ink due to the movement of the carriage. Ink can be reliably supplied to the recording head while maintaining a negative pressure suitable for printing, and further, leakage of ink from the ink supply port due to temperature change and leakage of ink from the recording head can be prevented.
Various structures of the ink tank valve provided at the position where the ink chamber and the ink supply unit are divided have been proposed. For example, the structure shown in FIGS. 1 and 2 can be preferably exemplified.
[0007]
FIG. 1 is a cross-sectional view showing an example of an ink tank valve, and FIG. 2 is a partial cross-sectional view showing an example of a disk-like valve body used in the ink tank valve. The ink tank valve C is provided at a position where the ink chamber A and the ink supply part B are divided. The valve body 1 used for the ink tank valve C has an ink supply hole 3 in the center, and a peripheral part. Is made of a disk-like elastic material reinforced and fixed by a hard material 2 such as polypropylene. The disk-shaped valve body 1 is supported by a movable support 5 having a spring 6 and is in contact with the fixed valve seat 4 when the recording is not performed, so that the ink tank valve C is closed. At the time of recording, the ink in the ink supply part B is supplied to the recording head part, so that the ink in the ink supply part B decreases and a negative pressure is applied. As a result, the movable support 5 moves in the direction in which the spring 6 is compressed, whereby the disc-shaped valve body 1 is separated from the fixed valve seat 4 and the ink tank valve C is opened, and the ink chamber A is opened. Ink is supplied to the ink supply part B through the ink supply hole 3. As a result, when the negative pressure in the ink supply part B is eliminated, the valve body 1 is again brought into contact with the fixed valve seat 4 by the movable support 5 and the supply of ink to the ink supply part B is stopped.
In the ink tank valve having such a structure, it is important that ink corresponding to the amount of ink ejected from the recording head during recording can be satisfactorily supplied. To that end, a disc-like valve body used for the ink tank valve is important. It is desirable that the reaction force when deformed is small. However, the disc-shaped valve body used in the conventional ink tank valve is usually about 0.4 mm thick having the structure shown in FIG. 2, and the reaction force when deformed is not necessarily small. There has been a problem that the ink supply cannot sufficiently follow the amount of ink ejected from the recording head.
[0008]
[Problems to be solved by the invention]
The present invention provides an ink tank valve for satisfactorily supplying ink corresponding to the amount of ink ejected from the recording head during recording from the ink chamber to the recording head portion, particularly in an ink jet recording apparatus, under such circumstances. The object is to provide a suitable fluid supply valve.
[0009]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventors have found that a disc-shaped valve body provided with at least one bent portion in the radial direction between the fluid supply hole portion and the peripheral portion is bent. It has been found that the reaction force at the time of deformation is smaller than that in which no part is provided, and that a fluid supply valve using such a valve body can be adapted to its purpose. The present invention has been completed based on such findings.
That is, the present invention has a fluid supply hole in the center, so that the disk-shaped valve body periphery is obtained by injection molding of resilient material reinforced fixed rigid material, corresponding to the previous SL fluid supply hole In the fluid supply valve which is supported by a movable support body provided with a spring so as to abut on the fixed valve seat and which opens and closes the fluid supply hole by contacting and separating from the fixed valve seat, A structure in which at least one bent portion is provided in the radial direction between the fluid supply hole portion and the peripheral portion, and the cross-sectional shape of the bent portion is continuously provided with concave and convex bent portions. A fluid supply valve is provided.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The fluid supply valve of the present invention has a structure in which a disc-like valve body having a fluid supply hole in the center opens and closes a fluid supply hole by making contact with and separating from a fixed valve seat arranged so as to correspond to the fluid supply hole. have. The disc-shaped valve body is made of an elastic material, and the peripheral edge is reinforced and fixed with a hard material.
As a fluid supply valve having such a structure, for example, an ink tank valve (FIG. 1) in the above-described ink jet recording apparatus can be cited as a representative one.
Hereinafter, the fluid supply valve of the present invention will be described using the ink tank valve as an example.
As shown in FIG. 1, the ink tank valve according to the present invention is disposed at a position where the ink chamber A and the ink supply part B are divided, and the operation mechanism thereof is as described above. The thickness of the disc-like valve body in this ink tank valve is usually in the range of 0.1 to 0.5 mm, preferably 0.2 to 0.4 mm. The diameter of the fluid (ink) supply hole provided in the center is usually in the range of 0.5 to 2 mm.
Moreover, there is no restriction | limiting in particular about the magnitude | size, ie, diameter, of this disc-shaped valve body, Although it selects suitably according to various situations, Generally it is about 10-30 mm.
[0011]
In the present invention, this disc-shaped valve body needs to be provided with at least one bent portion in the radial direction between the fluid supply hole portion and the peripheral portion in order to reduce the reaction force at the time of deformation. .
The method of providing the bent portion is not particularly limited, but for example, a bent portion, particularly a concave or convex cross-sectional shape provided in the circumferential direction is preferable. Specifically, (1) one bent portion having a concave cross section along the circumferential direction is provided in the vicinity of the peripheral edge (see FIG. 7), and (2) along the circumferential direction in the vicinity of the peripheral edge. In view of the effect, a cross-sectional shape in which concave and convex bent portions are provided one by one in succession (see FIGS. 8 to 10) is preferable.
Thus, by providing a bent portion in the disc-shaped valve body, the stress when the valve body is deformed concentrates on the bent portion, and as a result, the reaction force of the disc-shaped valve body without the bent portion is increased. However, due to the shape of the bent part, deformation due to shrinkage may occur during injection molding, and displacement (displacement during shrinkage) may occur in the center of the disk. What has a bending part shape that a displacement becomes as small as possible is preferable.
[0012]
FIG. 3 is a partial cross-sectional shape diagram showing an example of a disc-shaped valve body provided with a bent portion for explaining displacement during contraction. A portion surrounded by a dotted line is a shape before contraction, and a portion surrounded by a solid line is a shape after contraction. In the present invention, the contraction displacement is defined as + displacement for the ink supply unit side and-displacement for the ink chamber side. Reference numeral 2 denotes a hard material portion in which the peripheral edge of the disc-like valve body is reinforced and fixed, and 3 denotes an ink (fluid) supply hole.
In addition, the disc-shaped valve body preferably has good releasability from the mold after injection molding. Therefore, it is desirable to select the bent portion shape so that releasability is good.
In the disk-like valve body having the shape shown in FIGS. 7 to 10, the disk-like valve body having the shape shown in FIG.
[0013]
The disc-shaped valve body in the fluid supply valve of the present invention is made of an elastic material. The elastic material includes at least one polymer block mainly composed of a vinyl aromatic compound and a heavy body mainly composed of a conjugated diene compound. What contains the thermoplastic elastomer of the copolymer which consists of at least one unification block is used.
Examples of the thermoplastic elastomer include (1) a block copolymer of crystalline polyethylene obtained by hydrogenating a block copolymer of polybutadiene and butadiene-styrene random copolymer and ethylene / butylene-styrene random copolymer. Polymer,
(2) Obtained by hydrogenating a block copolymer of polybutadiene and polystyrene, a block copolymer of polyisoprene and polystyrene, or a block copolymer of polybutadiene or ethylene-butadiene random copolymer and polystyrene. For example, diblock copolymer of crystalline polyethylene and polystyrene, styrene-ethylene / butylene-styrene triblock copolymer (SEBS), styrene-ethylene / propylene-styrene triblock copolymer (SEPS), etc. Styrene-ethylene / butylene-styrene block copolymer or styrene-ethylene / propylene-styrene block copolymer,
And so on.
[0014]
Among these, a block copolymer comprising at least one polymer block mainly composed of a vinyl aromatic compound and at least one polymer block mainly composed of a conjugated diene compound, as mentioned in (2). From the viewpoint of durability, a hydrogenated block copolymer obtained by hydrogenation of a polymer having a number average molecular weight of 30000 or more is preferred. The upper limit is not particularly limited, but is usually about 400,000.
That is, it is obtained by hydrogenating a block copolymer comprising at least one polymer block mainly composed of a vinyl aromatic compound (1 segment) and at least one polymer block mainly composed of a conjugated diene compound. A block copolymer having at least two polymer blocks mainly composed of vinyl aromatic compound and at least one polymer block mainly composed of conjugated diene compound (for example, styrene-butadiene-styrene block) is preferable. More preferred is a hydrogenated block copolymer obtained by hydrogenating a copolymer, a styrene-isoprene-styrene block copolymer, or the like.
[0015]
In the elastic material used for the disc-shaped valve body according to the present invention, a softening agent can be blended as desired for the purpose of reducing the hardness of the thermoplastic elastomer. The softener is not particularly limited, and any softener can be selected and used from those conventionally used as plasticizers and rubber softeners.
In the elastic material, the organic polymer material constituting the elastic material preferably has a three-dimensional continuous network skeleton structure, and the formed three-dimensional continuous network skeleton structure has an average diameter of 50 μm. Hereinafter, preferably 30 μm or less, and the average diameter of the cells (mesh) is 500 μm or less, preferably 300 μm or less. The volume fraction of the polymer organic material is expressed as [volume of polymer organic material / (volume of polymer organic material]. + Volume of softening agent)] × 100 (%), the volume fraction of the polymer organic material is preferably 50% or less, particularly 33% or less.
This elastic material can be used in combination with known resin components and various additives for improving various properties. As the resin component, for example, polyphenylene ether resin, polyolefin resin, polystyrene resin or the like can be used alone or in combination. By adding these, it is possible to improve the compression set, workability and heat resistance of the elastic material according to the present invention.
[0016]
Examples of the additive include flame retardants, antibacterial agents, light stabilizers, ultraviolet absorbers, antioxidants, inorganic and organic fillers, colorants, and silicone oils.
The disc-shaped valve body used in the present invention has a peripheral portion reinforced and fixed with a hard material, and the hard material is not particularly limited, but plastic such as polypropylene resin is preferably used. In this case, for example, a plastic material as a base material is melt-injected and molded in a mold, and then the elastic material is melt-injected and molded, and the elastic material is laminated and integrated on the surface of the plastic molding. Color molding methods can be employed. Alternatively, after plastic is melt-injected and molded into a mold, the molded product is inserted into another mold, and an elastic material is melt-injected and molded on the surface of the plastic. An insert molding method in which materials are laminated and integrated can be employed.
[0017]
【Example】
EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
The reaction force of the obtained disc-shaped valve body was measured according to the method shown below.
<Method for measuring reaction force>
FIG. 4 is a schematic view of an apparatus for measuring the reaction force of a disc-shaped valve body. First, a sample disc-shaped valve body 1 is placed on a high-precision load meter 11. Next, the probe 12 attached to the high-precision displacement measuring machine is lowered, and the point at which the load cell 11 starts to become positive from 0 is defined as the zero point of displacement. Next, a predetermined displacement is given to the disc-shaped valve body 1 by the probe 12, and the load at that time is measured to obtain a reaction force.
Preparation Example 1
An elastic material for producing a disc-shaped valve body was prepared as follows.
That is, 100 parts by weight of styrene-ethylene / propylene-styrene triblock copolymer (SEPS) (number average molecular weight 100,000, solubility parameter (SP value) 8.5), paraffin oil [made by Idemitsu Kosan Co., Ltd., product Name: PW380] (Number average molecular weight 750, SP value 7.8) 150 parts by weight and polypropylene resin 13 parts by weight were sufficiently kneaded to prepare an elastic material. The hardness measured in accordance with JIS K6301 (A type) was 20.
[0018]
Comparative Example 1
Using the elastic material and polypropylene resin obtained in Preparation Example 1 and having the cross-sectional shape shown in FIG. 5 by the two-color molding method (however, FIG. 5 is a half-half cross-sectional shape), the fluid supply hole in the center 3 and a uniform disc-shaped valve body having a thickness of 0.4 mm in which the peripheral portion is reinforced and fixed with a hard material made of polypropylene resin.
About this valve body, the reaction force in case a displacement is 0.2 mm was calculated | required.
The results are shown in Table 1.
Comparative Example 2
Using the elastic material and polypropylene resin obtained in Preparation Example 1 and having the cross-sectional shape shown in FIG. 6 (however, FIG. 6 is a half-half cross-sectional shape) by a two-color molding method, the fluid supply hole in the center 3 and a disc-shaped valve body in which a thin portion having a wide thickness of 0.2 mm, the peripheral portion of which is reinforced and fixed with a hard material made of polypropylene resin, is provided along the circumferential direction. The width of the thin portion is 3 mm.
About this valve body, the reaction force in case a displacement is 0.2 mm was calculated | required.
The results are shown in Table 1.
[0019]
Examples 1-4
FIG. 7 (Example 1), FIG. 8 (Example 2), FIG. 9 (Example 3), and FIG. 10 (Example) by the two-color molding method using the elastic material and polypropylene resin obtained in Preparation Example 1. 4) (however, these figures are a half-sectional shape), the fluid supply hole 3 is provided at the center, and the peripheral portion is reinforced and fixed with a hard material 2 made of polypropylene resin. A disc-shaped valve body having a bent portion in the vicinity of the peripheral edge was prepared.
About each valve body, while calculating | requiring the reaction force in case a displacement is 0.2 mm, the displacement amount at the time of shrinkage | contraction at the time of shaping | molding was measured. The results are shown in Table 1.
[0020]
[Table 1]

[0021]
As can be seen from Table 1, the comparative example 2 in which most of the disc-shaped valve body is thin has the same reaction force as that of the comparative example 1 of the conventional product. This is because when most of the disc-shaped valve body is thinned, the radial shrinkage during injection molding increases, and as a result, the reaction force does not decrease. In Examples 1 to 4, the reaction force is about 30% lower than that in Comparative Example 1. However, in Examples 1 and 3, the amount of displacement at the time of contraction is large, and when Example 2 and Example 4 having a small amount of displacement at the time of contraction are compared, Example 4 is more releasable after molding. It is good. Therefore, in consideration of the reaction force, the amount of displacement at the time of contraction, and the releasability, the fourth embodiment is the best among the first to fourth embodiments.
[0022]
【The invention's effect】
The fluid supply valve of the present invention is particularly suitably used as an ink tank valve of an ink jet recording apparatus, and satisfactorily supplies ink corresponding to the amount of ink discharged from the recording head during recording from the ink chamber to the recording head unit. be able to.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating an example of an ink tank valve.
FIG. 2 is a partial cross-sectional view showing an example of a disc-like valve body used for the ink tank valve.
FIG. 3 is a partial cross-sectional shape showing an example of a disc-shaped valve body provided with a bent portion for explaining displacement during contraction.
FIG. 4 is a schematic view of an apparatus for measuring a reaction force of a disc-shaped valve body.
5 is a partial cross-sectional view of a disc-shaped valve body manufactured in Comparative Example 1. FIG.
6 is a partial cross-sectional view of a disc-shaped valve body produced in Comparative Example 2. FIG.
7 is a partial cross-sectional view of a disc-shaped valve body manufactured in Example 1. FIG.
FIG. 8 is a partial cross-sectional view of the disc-shaped valve body manufactured in Example 2. FIG. 9 is a partial cross-sectional view of the disc-shaped valve body manufactured in Example 3.
10 is a partial cross-sectional view of a disc-shaped valve body produced in Example 4. FIG.
[Explanation of symbols]
1: Disc-shaped valve body 2: Hard material 3: Ink (fluid) supply hole 4: Fixed valve seat 5: Movable support body 6: Spring 11: High precision load cell 12: Probe A: Ink chamber B: Ink supply part C : Ink tank valve

Claims (2)

Has a fluid supply hole in the center, the fixed valve seat disc-shaped valve body periphery is obtained by injection molding of resilient material reinforced fixed hard material has been arranged so as to correspond to the prior SL fluid supply hole A fluid supply valve that is supported by a movable support provided with a spring so as to abut against the fixed valve seat and opens and closes the fluid supply hole by contacting and separating from the fixed valve seat. Characterized in that at least one bent portion is provided in the radial direction along the circumferential direction, and the cross-sectional shape of the bent portion is continuously provided with a concave shape and a convex bent portion. Fluid supply valve.   The fluid supply valve according to claim 1, wherein the disc-shaped valve body is provided with a bent portion in the circumferential direction in the vicinity of the peripheral edge portion.

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