JP4698795B2 - Annular packing - Google Patents

Description

【００２１】
ここで、これら割合の寸法値を上記数式（１）で説明すると、脚部４の窄小率は、摺動時に円形頭部３の摺接辺３ａが摺動方向へ変形する量ｙに対応して基端４ａに生じる曲げ応力を極力小さくするために、摺接辺３ａの断面半径（Ｒ）の３６〜３８％と比較的小さい値とした。このとき、円形頭部３の摺接辺３ａが半径方向へ変形する量ｘは、基端４ａから円形頭部３の摺接辺３ａまでの距離をＬとすると、数値解析の結果から近似的に前記数式（１）と表現された。この寸法値の範囲は、確実な水密性を保ちつつ円滑な摺動を得るために必要適正な値ｘが、値ｙをむやみに大きくすることなく、かつ基端４ａでの曲げ応力を極力小さく制御することができるように、数式（１）の関係式を用いて求められ、さらに、これを実験により確認されたものである。
【００２３】
上記の各実施例では、いずれも頭脚部２の円形頭部３を外周側に、脚部４を内周側に設けた環状パッキン１について説明したが、この各部３，４を内外周側に入れ替えて逆に設けて環状パッキン１を構成する（図示省略）ことも可能である。
【００２４】
【発明の効果】
この発明の環状パッキンは上記で説明した構成から成り、パッキンにおける断面円形の円形頭部を窄小頚部と空洞部を有する脚部により、摺動時のつぶれおよび揺動傾斜による応力を吸収して、円形頭部がもついずれの方向へも均一に弾性力が働く作用を活用し、これによって摺動時のシリンダー壁面への円形頭部の圧接力を均一に維持することができる。
【００２５】
従って、バルブにおける摺動時のパッキンの円形頭部摺接辺の揺動傾斜方向に関わりなく、常にシリンダー壁への弾性力が変わらないので、円滑な摺動が得られ、ことに、摺動方向を切り換える転換時の始動に顕著に現れると共に、確実な水密性も同様に得られ、製造上ではつぶれ代の許容量が寛容となって生産効率を向上させるものである。
【図面の簡単な説明】
【図１】この発明を実施せる環状パッキンの一部を欠いて示す正面図である。
【図２】図１の環状パッキン要部を拡大して示す断面図である。
【図３】この発明の環状パッキンを装着したボールタップ式バルブの要部を縦断して示す正面図である。
【図４】図３のバルブ要部を拡大して示す断面図である。
【図５】図４における環状パッキンの摺動過程での変形状態を示す断面図である。
【図６】この発明の他の実施例を示す環状パッキンの一部を切欠いて示す正面図である。
【符号の説明】
１ パッキン
２ 頭脚部
３ 円形頭部
３ａ 摺接辺
３ｂ 側辺
３ｃ 窄小頚部
４ 脚部
４ａ 基端
５ 基台部
６ 空洞部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an annular packing for achieving watertightness between a valve rod that makes a stroke motion such as a spool valve in various valves such as a ball tap valve and a cylinder.
[0002]
[Prior art]
Conventionally, this kind of annular packing has a track shape in which the outer and inner peripheral sliding surfaces are formed in a cross section R, and a peanut shell in a cross section provided with recesses near the center of both side surfaces between the inner and outer periphery. Cross-section ballpoint pen tip (see Japanese Patent Application Laid-Open No. 7-269733) with a small-diameter R-shaped part at the tip of the sliding contact surface formed like a head, and a cross-over inverted T-shape (T-shaped) with a wide base The one configured in such a way has been proposed.
[0003]
For annular packing, it is required that the deformation (crushing) allowance of the sliding contact surface during sliding is 0.2 mm or less to improve both sliding and watertightness, and that dimensional accuracy is strictly required. It is also known that
[0004]
[Problems to be solved by the invention]
However, with respect to these conventional annular packings, in the cross-sectional track type and cross-sectional peanut shell type packings, the R portion is equal to the entire width (thickness), and the largest elastic force acts in the radial direction having the height. Is applied with an elastic stress acting diagonally in the width (thickness) direction during sliding, which is inclined along the sliding direction of the sliding contact portion on the outer periphery (inner periphery). A phenomenon occurs in which sliding resistance increases to prevent smooth sliding.
[0005]
Next, the cross-section ballpoint pen-shaped packing has a configuration in which the tip R-shaped portion forms a part of a point-like portion that spreads in an octagonal shape, so that the elastic force of the tip R-shaped portion that inclines during sliding differs depending on the angle, and is uniform Because it is difficult for the elastic force to work, the water tightness is poor and the smoothness at the start is also lacking.
[0006]
In addition, since the annular packing having an inverted T-shaped cross section has the same wall thickness, the elastic stress on the cylinder wall at the outer peripheral or inner peripheral edge acts the largest in the diametrical direction like other packings, and when sliding The elastic stress was different depending on the angle of pressure contact with the cylinder wall at the outer and inner peripheral edges of the cylinder, which hindered water tightness and smooth sliding at the start.
[0007]
Thus, all of the conventional annular packings have different elastic stresses due to changes in the pressure contact angle of the inner and outer peripheral edges to the cylinder wall during sliding, and smooth sliding and reliable watertightness cannot be expected. In particular, since the sliding resistance becomes the largest at the start of switching the sliding direction and the smooth sliding start cannot be performed, the valve cannot be opened and closed accurately, and the deformation (crushing) allowance on the sliding surface of the packing is allowed. There were problems such as requiring strict manufacturing precision that had to clear the range.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention has a semicircular cross section around the outer periphery or inner periphery of an annular packing made of an elastic material such as rubber, and the arc side edge of the semicircular cross section is slightly wide in the width of its diameter. A round head with a narrow neck is formed by narrowing the extended side, and both sides of the round neck of the circular head are extended in parallel to form legs with cavities on both sides. An annular packing characterized by a part is proposed.
[0009]
A circular head with a semicircular cross-section of the annular packing attached to the valve's sliding shaft or cylinder wall is in watertight pressure contact with the annular radial cylinder wall surface or sliding shaft surface by elastic force, and is circular when sliding. When the head slightly swings and tilts along the sliding direction, the elastic stress due to the swing tilt is absorbed by the leg portion having the hollow portion, and the circular head having a circular cross section by the narrow neck portion is This also has a cross-section with the same diameter, and this is an elastic force that works equally in each direction of rocking and tilting, so that reliable water tightness and smooth sliding can be obtained. Smooth start.
[0010]
The packing formed on the circular head of the circular head diagonally facing the constricted cervical portion in the same direction as the arc side controls the swinging inclination stress of the circular head during sliding, and any sliding resistance is controlled. In addition to ensuring uniform watertightness in the direction of, the sliding and starting are made smoother by assisting the inclination restoring force when switching the sliding direction.
[0011]
The base part provided at the base end part of the leg part stably supports the circular head part, and by forming the corner part with the leg part into a concave rounded shape, ensuring water tightness, sliding and starting. Make it even smoother.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the annular packing according to the present invention will be described. The annular packing is used by being fitted in a receiving groove provided on an outer peripheral surface of a valve stem or an inner peripheral surface of a cylinder which performs stroke movement in various valves such as a ball tap valve. It is made of elastic materials such as rubber and urethane rubber, and the entire cross section with the base and head and leg parts integrated is formed into a convex or inverted convex ring, and the outer periphery or inside of the head and leg parts The circumferential sliding contact side is formed in a semicircular cross section, and the circular arc side end of this semicircular cross section is formed into a circular head having a constricted cervical part by constricting both sides slightly extended by the width of the diameter, This round head cervical cervical part is extended in parallel to form a leg part having a hollow part on both sides to form a head leg part having a cross section of a wooden cross section. A base with a wide band shape is connected to the base end of the leg in the direction along the ring. Molded to constitute the annular packing.
[0013]
【Example】
An embodiment of the annular packing will be described with reference to FIGS. 1 to 5. FIG. 1 is a front view showing a part of the embodiment of the annular packing according to the present invention, and FIG. 2 is a cross-sectional view of the main portion of the annular packing. 3 is a cross-sectional view of a ball tap valve equipped with an annular packing, FIG. 4 is a cross-sectional view of an essential part when the annular packing is slid, and FIG. 5 is an essential part showing a deformed state when the annular packing is slid. The ring-shaped packing 1 is formed integrally with a convex section having a head leg portion 2 on the outer peripheral side and a base portion 5 on the inner peripheral side, and the head leg portion 2 is formed on the outer peripheral sliding contact side 3a. Is formed in a semicircular cross section, and a circular head 3 formed by constricting both side edges 3b and 3b obtained by slightly extending the side edges of the arc of the semicircular cross section by the width of the diameter (R), and the constriction thereof. A leg portion 4 having a hollow portion 6 formed on both sides on both sides of the small neck extending in parallel from the small neck portion 3c. The proximal end 4a of the parts 4 in the center in the width direction along the annular wide strip of the base portion 5 connected integrally molded to configure the annular packing 1.
[0014]
A round (arc) corresponding to 32 to 36% of the radius (R) of the sliding contact side 3a is attached to the corner of the narrow neck 3c diagonally opposite to the cross-sectional arc of the sliding contact side 3a of the circular head 3; Further, the corner portions of the base portion 5 and the base end 4a of the leg portion 4 are similarly provided with a round (arc), and the annular packing 1 is a ball tap type valve or the like as shown in FIGS. In the ball tap type valve 8, an endless or endless annular support frame 7, 7 made of a hard material such as synthetic resin is attached to the receiving groove 9 b provided on the spool 9 a of the spindle 9 from above and below. Installing.
[0015]
The spindle 9 with the packing 1 is slid up and down in the cylinder 8a by a lever 11 connected to an insulator rod 10 that swings up and down by the buoyancy of the tip float, and the valve body 9c on the spindle 9 The seat 8b is opened and closed to supply or stop the fluid.
[0016]
The round (arc) portion provided in the constricted cervical portion 3c of the circular head 3 acts as a smooth resistance to the swinging inclination stress during sliding as shown in FIGS. When switching the direction, the stress due to the swinging inclination shown by the broken line of the sliding contact side 3a of the circular head 3 is controlled, and the restoring force at the time of changing the swinging direction is assisted to make the sliding and starting more smooth and reliable. By setting this round (arc) part to 32 to 36% of the cross-sectional radius (R) of the slidable contact side 3a diagonally opposite, the above balanced action can be easily achieved. can get.
[0017]
Further, by providing the same round (arc) part as the narrow neck part 3c at the corner part between the base end 4a and the base part 5 of the leg part 4, smoother starting and sliding can be obtained. is there.
[0018]
【Example】
As another embodiment, the annular packing shown in FIG. 6 comprises the head leg 2 with the circular head 3 and the leg 4 formed with the width of the narrow neck 3c without the round (arc) part, In the packing 1 in which the base end 4a of the leg portion 4 is integrally connected to the base portion 5, the narrow neck portion is formed so that the central portion of the leg portion 4 hits the extended circumference having a semicircular cross section of the circular head portion 3. By setting the length (height) of the leg 4 from 3c to the base end 4a, the circular head 3 has a circular cross-section with an equal diameter in any direction, and is perpendicular to the annular radial direction. Equal elastic force works in the direction of. In addition, by absorbing the rocking inclination stress during sliding by the narrow neck 3c and the cavity 6 of the leg 4, the elastic force can be applied equally to any of the rocking inclinations to ensure reliable water tightness. Smooth sliding is obtained.
[0019]
In the annular packing 1 in these embodiments, the length (height) of each part in the annular radial direction is set to the arc side end of the sliding contact side 3 a with respect to the cross-sectional radius (R) of the sliding contact side 3 a of the circular head 3. Next, the side 3b is 45 to 49%, the legs are 88 to 92%, the base 5 is 154 to 158%, and the width (thickness) of the base 5 is 497 to 503%. The width (thickness) of the leg portion 4 is formed by setting the narrowing ratios on both sides of the leg portion 4 forming the portion 6 to 36 to 38% with respect to the cross-sectional radius (R) of the sliding contact side 3a. Thus, it has been confirmed by experiments that the balance between water tightness and smooth sliding can be maintained best, and the circumference of the cross-sectional radius of the sliding contact side 3a of the circular head 3 is The circular head 3 having a circular cross-section by extending to the center in the length (height) direction is perpendicular to the annular radial direction. In direction can be derived function of uniformly resilient works.
[0020]
[Expression 1]

[0021]
Here, the dimensional values of these ratios will be explained by the above formula (1). The narrowing ratio of the leg 4 corresponds to the amount y by which the sliding contact side 3a of the circular head 3 is deformed in the sliding direction during sliding. In order to minimize the bending stress generated at the base end 4a, the value is set to a relatively small value of 36 to 38% of the cross-sectional radius (R) of the sliding contact side 3a. At this time, the amount x of deformation of the sliding contact side 3a of the circular head 3 in the radial direction is approximated from the result of numerical analysis, where L is the distance from the base end 4a to the sliding contact side 3a of the circular head 3. Is expressed as Equation (1). This range of dimension values is such that the appropriate value x necessary to obtain smooth sliding while maintaining reliable water tightness does not increase the value y unnecessarily, and the bending stress at the base end 4a is minimized. In order to be able to control, it was calculated | required using the relational expression of Numerical formula (1), and also this was confirmed by experiment.
[0023]
In each of the above-described embodiments, the circular packing 1 in which the circular head 3 of the head / leg portion 2 is provided on the outer peripheral side and the leg portion 4 is provided on the inner peripheral side has been described. It is also possible to configure the annular packing 1 by replacing it with the reverse (not shown).
[0024]
【The invention's effect】
The annular packing of the present invention has the above-described configuration, and absorbs stress due to crushing and swinging inclination when sliding by a leg portion having a narrow neck portion and a hollow portion in the circular head of the cross section of the packing. By utilizing the action of the elastic force uniformly acting in any direction of the circular head, the pressing force of the circular head to the cylinder wall surface during sliding can be maintained uniformly.
[0025]
Therefore, since the elastic force to the cylinder wall does not always change regardless of the swinging and tilting direction of the sliding contact side of the circular head of the packing when sliding on the valve, smooth sliding is obtained. In addition to being conspicuous in starting at the time of switching the direction, reliable water tightness is obtained as well, and in production, the allowance for crushing allowance is tolerated and production efficiency is improved.
[Brief description of the drawings]
FIG. 1 is a front view showing a part of an annular packing for carrying out the present invention.
2 is an enlarged cross-sectional view showing a main part of the annular packing in FIG. 1. FIG.
FIG. 3 is a front view showing a main part of a ball tap valve equipped with the annular packing of the present invention in a longitudinal section.
4 is an enlarged cross-sectional view showing a main part of the valve shown in FIG. 3;
5 is a cross-sectional view showing a deformed state in the sliding process of the annular packing in FIG. 4;
FIG. 6 is a front view showing a part of an annular packing showing another embodiment of the present invention .
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Packing 2 Head leg part 3 Round head part 3a Sliding contact side 3b Side 3c Constriction neck part 4 Leg part 4a Base end 5 Base part 6 Cavity part

Claims (2)

Circular head having a narrow neck by constricting the side formed by slightly extending the arc edge of the sliding contact side with a semicircular cross section around the outer periphery or inner periphery of the annular packing. An annular packing formed by forming a head and leg part with a leg part formed by extending the circular head part and the narrow neck part in parallel with the circular head part,
The leg portions having hollow portions extending in parallel on both sides of the narrow neck portion are formed, and a wide base portion is integrally formed along the annular shape at the base end of the leg portion of the head leg portion. and,
The head and leg portion is formed in a concave radius in the same direction as the cross-section arc side of the circular head whose diagonal neck is diagonally opposed,
The base is formed in a rounded corner at the corner with the leg,
The length of the packing in the radial direction is 45 to 49% on the side following the arc edge of the sliding contact side and 88 to 92% on the leg part with respect to the cross-sectional radius (R) of the sliding contact side of the circular head. , Base parts are formed to 154-158%,
The width of this base part is set to 497 to 503%, and the narrowing ratios on both sides of the leg part forming the hollow part are set to 36 to 38%, respectively .
Annulus in which the concave radius at the narrow neck and the concave radius at the corner of the base and leg are set to 32 to 36% of the cross-sectional radius (R) of the sliding contact side of the circular head, respectively . Packing. The annular packing according to claim 1, wherein the circumference of the cross-sectional radius of the sliding contact side of the circular head is located at the center in the length direction of the leg portion.

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