JP4217470B2 - Electric control valve - Google Patents

Description

【００４７】
ここで、雌ねじに作用する本体底部（弁室底面）との水平方向の力Ｍについて考える。
Ｍ＝ｆｍ・ｃｏｓβ−Ｐ・ｓｉｎβ±ｆｈ …（６）
この時、雌ねじが図６の右方向に動く条件を求めると、
Ｍ＞０
∴ｆｍ・ｃｏｓβ−Ｐ・ｓｉｎβ−ｆｈ＞０ …（７）
（７）式に（５）式を代入する。
ｆｍ・ｃｏｓβ−Ｐ・ｓｉｎβ−｛μｈ（Ｐ・ｃｏｓβ＋ｆｍ・ｓｉｎβ−Ｆｎ）｝＞０ …（８）
【００４８】
ｆｍについてまとめる。
ｆｍ（ｃｏｓβ−μｈ・ｓｉｎβ）−Ｐ・ｓｉｎβ−｛μｈ（Ｐ・ｃｏｓβ−Ｆｎ）｝＞０ …（９）
（９）式に（２）式を代入する。
μｍ・Ｐ（ｃｏｓβ−μｈ・ｓｉｎβ）−Ｐ・ｓｉｎβ−｛μｈ（Ｐ・ｃｏｓβ−Ｆｎ）｝＞０ …（１０）
【００４９】
Ｐについてまとめる。
Ｐ（μｍ・ｃｏｓβ−μｍ・μｈ・ｓｉｎβ）−Ｐ・ｓｉｎβ−Ｐ・μｈ・ｃｏｓβ＋μｈ・Ｆｎ＞０ …（１１）
Ｐ｛（μｍ−μｈ）ｃｏｓβ−（μｍ・μｈ＋１）ｓｉｎβ｝＋μｈ・Ｆｎ＞０ …（１２）
ここで、（１２）式の｛｝のなかを、
（μｍ−μｈ）ｃｏｓβ−（μｍ・μｈ＋１）ｓｉｎβ＝Ａ…（１３）
と置くと、
Ｐ・Ａ＋μｈ・Ｆｎ＞０ …（１４）
【００５０】
更に、（２）、（３）式より、
Ｐ＝Ｆｕ・ｃｏｓβ＋Ｆｎ・ｃｏｓβ−Ｑ・ｓｉｎβ …（１５）
、であり、これを（１４）式に代入すると、
（Ｆｕ・ｃｏｓβ＋Ｆｎ・ｃｏｓβ−Ｑ・ｓｉｎβ）・Ａ＋μｈ・Ｆｎ＞０ …（１６）
となる。
これを展開して整理する。
Ｆｕ・Ａ・ｃｏｓβ＋Ｆｎ（Ａ・ｃｏｓβ＋μｈ）−Ｑ・ｓｉｎβ・Ａ＞０ …（１７）
【００５１】
ここで、Ａの正負を求める。
Ａ＜０と、仮定すると、（１３）式より、
（μｍ−μｈ）ｃｏｓβ−（μｍ・μｈ＋１）ｓｉｎβ＜０…（１８）
μｍ−μｈ−（μｍ・μｈ＋１）ｔａｎβ＜０…（１９）
μｍ、μｈは、ともに樹脂−金属間の摩擦係数であるので、μｍ＝μｈとすると、μｍ−μｈ＝０より、（１９）式は、
−（μｍ・μｈ＋１）ｔａｎβ＜０…（２０）
μｍ＞０、μｈ＞０、ねじリード角β＝８．３９°で、ｔａｎβ＝０．１４７＞０であるので、（２０）式が成立する。よって、Ａ＜０の仮定も成立する。
【００５２】
Ａ＜０であるから、（１７）式は、
Ｆｕ・Ａ・ｃｏｓβ＞Ｑ・ｓｉｎβ・Ａ−Ｆｎ（Ａ・ｃｏｓβ＋μｈ）…（２１）
Ｆｕ＜Ｑ・ｔａｎβ−Ｆｎ（１＋μｈ／（Ａ・ｃｏｓβ）） …（２２）
となる。
これは、雌ねじが右方向に動く条件であるので、逆に右方向に動かない条件は下式（２３）で表される。
Ｆｕ＞Ｑ・ｔａｎβ−Ｆｎ（１＋μｈ／（Ａ・ｃｏｓβ）） …（２３）
【００５３】
以上により、ロータ反転時に雌ねじが右方向（ＣＣＷ方向）に動かないためには、上ばね荷重Ｆｕが、Ｑ・ｔａｎβ−Ｆｎ（１＋μｈ／（Ａ・ｃｏｓβ））の値以上であればよい。
【００５４】
上述した上ばね３２のばね荷重と下ばね３５のばね荷重の最適設定により、弁閉反転時に雌ねじ部材１８が弁開方向に回転変位することを阻止するねじ面摩擦力が雄ねじ部２４と雌ねじ孔２２とのねじ係合面に作用し、ロータ反転時に雌ねじ部材１８が動かなくなる。
【００５５】
これにより、基点出し時等のロータ反転時に、衝突音や振動が生じることがなくなり、優れた動作静粛性、耐久性が得られるようになる。
【００５６】
【発明の効果】
以上の説明から理解される如く、この発明による電動式コントロールバルブによれば、板ばねによる雌ねじ部材の回転方向の付勢やばね荷重の適正化により、基点出し時等のロータ反転時に、衝突音や振動が生じることがなくなり、優れた動作静粛性、耐久性が得られるようになる。
【図面の簡単な説明】
【図１】 この発明による電動式コントロールバルブの実施形態１を示す縦断面図である。
【図２】 この発明による電動式コントロールバルブの実施形態１の要部の分解斜視図である。
【図３】 この発明による電動式コントロールバルブの実施形態１の要部の拡大正面図である。
【図４】 この発明による電動式コントロールバルブの実施形態１の要部の拡大側面図である。
【図５】 この発明による電動式コントロールバルブの実施形態２を示す縦断面図である。
【図６】 この発明による電動式コントロールバルブの実施形態２におけるばね荷重適正化の計算モデル図である。
【符号の説明】
１０ 弁ハウジング
１１ 一次側ポート
１２ 二次側ポート
１３ 弁室
１４ 弁ポート
１５ 弁室底面
１８ 雌ねじ部材
１８Ｄ 回り止め凹溝
１９ 弁体
２０ 弁ばね
２１ ガイド部材
２１Ａ 回り止め帯状部
２３ 雄ねじ部材
２５ フランジ部
２６ 固定側ストッパ部
２８ スペーサ
３２ 上ばね（第１のばね）
３４ 板ばね部材
３５ 下ばね（第２のばね）
５０ ステッピングモータ
５１ ロータ
５２ ボス部
５３ ステータ組立体[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric control valve, and more particularly to an electric control valve that controls a refrigerant flow rate in a refrigeration / refrigeration / air conditioning system.
[0002]
[Prior art]
As an electric control valve that controls the flow rate of refrigerant in a refrigeration / refrigeration / air conditioning system, a male screw member is provided in the valve housing so as to be movable in the axial direction in a non-rotating state, and the female screw member is connected to the rotor of the stepping motor The valve port formed on the bottom surface of the valve chamber of the valve housing by a valve body provided so that the female screw member is moved in the axial direction by rotation of the rotor and the female screw member is movable in the axial direction only within a predetermined range. There is one that opens and closes (for example, Patent Document 1).
[0003]
In this electric control valve, the female screw member forms a valve body holder, and in the valve closed state, the female screw member abuts against the bottom of the valve chamber, and further axial movement in the valve closing direction is reliably restrained with high rigidity. In this constrained state, further rotation of the rotor in the valve closing direction is permitted by the axial movement of the male screw member, so that the phase adjustment of the stepping motor at the valve closing point, that is, the reference point is accurately performed with good reproducibility. .
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-343083
[Problems to be solved by the invention]
In the conventional electric control valve described above, the rotation prevention of the female screw member is an axial sliding engagement between the concave groove formed on the outer peripheral surface of the female screw member and the rotation stopper band portion provided on the fixing member on the valve housing side. Done in case. In this case, the lateral width of the concave groove is slightly larger than the lateral width of the detent band-shaped portion so that the female screw member can move in the axial direction, and there is an essential gap in the rotational direction between the detent band-shaped portion and the concave groove.
[0006]
For this reason, when the rotation of the rotor is reversed in the reference point finding, the female screw member together with the male screw member moves in the rotational direction of the rotation preventing portion in the rotational direction along with the rotation of the rotor. The groove side surface of the groove may collide with one side surface of the detent band-shaped portion. For this reason, vibration and collision noise are generated, and the durability and quiet operation of the electric control valve are hindered.
[0007]
The present invention has been made to solve the above-described problems, and avoids the occurrence of vibration and collision noise caused by the collision of the rotation-preventing portion of the female screw member that occurs when the rotation of the rotor is reversed, and has excellent durability. An object of the present invention is to provide an electric control valve that exhibits quiet operation.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, an electric control valve according to the present invention has a valve housing having a valve chamber and a valve port opened at the bottom of the valve chamber, and is movable in the axial direction in a non-rotating state with respect to the valve housing. A female screw member that is in contact with the bottom surface of the valve chamber at one end surface by axial movement, and is provided in the female screw member so as to be movable in the axial direction only within a predetermined range, and by the axial movement on the valve chamber bottom side, A valve body that closes the valve port and opens the valve port by an axial movement opposite to the bottom surface of the valve chamber; and a valve spring that biases the valve body toward the bottom surface of the valve chamber with respect to the female screw member. A male screw member screw-engaged with the female screw member, a multi-pole magnetized rotor and a stator, and a boss portion of the rotor is fixedly connected to the male screw member, and the male screw member is driven to rotate. A stepping motor, and the rotation stop of the female screw member is an axial sliding engagement between a concave groove formed in the axial direction on the female screw member and the fixing member on the valve housing side, and a rotation belt-like portion. And a pressing means using a spring or the like that presses one groove side surface of the concave groove against one side surface of the anti-rotation belt-like portion is provided between the concave groove and the anti-rotation belt-like portion.
[0009]
According to the electric control valve of the present invention, one groove side surface of the groove is pressed against one side surface of the non-rotating belt-like portion in advance by the pressing means, and the groove side surface of the groove is There is no collision with one side.
[0010]
In the electric control valve according to the present invention, as a detailed structure, the fixing member is a cylindrical rod-shaped guide member having the detent belt-like portions at a plurality of positions in the circumferential direction, and the female screw member is moved in the axial direction inside. The concave groove is formed on the outer peripheral surface of the female screw member, and a leaf spring sandwiched in an elastically deformed state between the concave groove and the detent belt-like portion is provided as the pressing means.
[0011]
According to the electric control valve of the present invention, one groove side surface of the concave groove on the outer periphery of the female screw member is pressed against one side surface of the guide member by the leaf spring in advance, and the groove of the concave groove is rotated when the rotor is rotated and reversed. The side surface does not collide with one side surface of the detent belt-shaped portion.
[0012]
In order to achieve the above-described object, an electric control valve according to the present invention includes a valve housing having a valve chamber and a valve port opened on the bottom surface of the valve chamber, and moves in the axial direction in a non-rotating state with respect to the valve housing. An internal thread member that comes into contact with the bottom surface of the valve chamber at one end surface by axial movement, and is movable in the axial direction only within a predetermined range on the internal thread member, and moves axially on the bottom side of the valve chamber A valve body that closes the valve port and opens the valve port by an axial movement opposite to the valve chamber bottom surface, and a valve that biases the valve body toward the valve chamber bottom surface with respect to the female screw member a spring, and the female screw member and the screw engagement with the externally threaded member, and a multi-pole magnetization of the rotor and the stator, to rotate the front Symbol male screw member that is fixedly coupled to the boss portion of the rotor stearate Ping motor and a first spring for urging the side of the valve chamber bottom surface of the male screw member through the boss portion of the rotor and the rotor, the side opposite to the side of the valve chamber bottom surface of the female screw member A female spring member that has a second spring that is urged against the female screw member, and the female screw member and a fixing member on the valve housing side are formed in a groove extending in the axial direction and a detent belt-like portion. The screw surface frictional force is applied to the screw engagement surfaces of the female screw member and the male screw member to prevent the female screw member from being rotationally displaced in the valve opening direction when the valve is closed. A spring load of the first spring and a spring load of the second spring are set.
[0013]
According to the electric control valve of the present invention, the screw that prevents the female screw member from being rotationally displaced in the valve opening direction when the valve is reversed by the optimum setting of the spring load of the first spring and the spring load of the second spring. Since the surface frictional force acts on the screw engaging surfaces of the female screw member and the male screw member, and the female screw member does not rotate and displace in the valve opening direction when the valve is closed , the groove side surface of the concave groove is There is no collision with one side .
[0014]
The optimum setting of the spring load may be performed so as to satisfy the following expression.
Fu> Q · tan β-Fn (1 + μh / (A · cos β))
A = (μm−μh) cosβ− (μm · μh + 1) sinβ
Where Fu: spring load of the first spring Fn: spring load of the second spring Q: force in the tangential direction during reversal β: screw lead angle μm: friction coefficient μh of the screw surface: valve housing fixed side and female screw member Friction coefficient of
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
1 to 4 show Embodiment 1 of an electric control valve according to the present invention.
[0016]
As shown in FIG. 1, the motorized control valve has a valve housing 10. In the valve housing 10, a primary side port 11, a secondary side port 12, a valve chamber 13, and a valve port 14 are formed. The valve port 14 opens at the center of the flat valve chamber bottom surface 15 of the valve chamber 13, and communicates the primary side port 11 and the secondary side port 12. A primary side joint 16 is connected to the primary side port 11, and a secondary side joint 17 is connected to the secondary side port 12.
[0017]
The valve chamber 13 has a circular shape with an upper opening, and a lower portion of the hollow shaft-shaped female screw member 18 is inserted into the valve chamber 13 so as to be movable in the axial direction. The female screw member 18 abuts on the valve chamber bottom surface 15 at the lower end surface 18A by movement in the axial direction, and is further restrained from descending (moving in the valve closing direction).
[0018]
The female screw member 18 supports the valve body 19 in a suspended manner so as to be movable in the axial direction, and forms a valve body holder. The valve body 19 is suspended and supported so as to be movable in the axial direction from the female screw member 18 by the flange portion 19A coming into contact with the stepped portion 18C of the hollow hole 18B of the female screw member 18, and is lowered (valve closed) by a valve spring 20 described later. Direction). The valve body 19 opens and closes the valve port 14 by a needle portion 19B protruding from the lower part of the female screw member 18 toward the valve chamber bottom surface 15 (downward), and the opening degree of the valve port 14 is quantitatively determined according to the axial position. Increase or decrease.
[0019]
A cylindrical rod-shaped guide member 21 is caulked and coupled to the upper surface of the valve housing 10 as one fixing member. The guide member 21 has three leg-shaped detent belt-like portions 21A extending in the axial direction at positions spaced in the circumferential direction.
[0020]
The upper portion of the female screw member 18 projects as an upper large diameter portion 18E from the valve chamber 13 above the valve housing 10, and is accommodated inside the guide member 21 so as to be movable in the axial direction. Three anti-rotation grooves 18D extending in the axial direction are formed on the outer peripheral surface of the upper large-diameter portion 18E of the female screw member 18, and the anti-rotation grooves 18D are slip-key type on the anti-rotation belt portion 21A. Axial sliding engagement. By this axial sliding engagement, the female screw member 18 is prevented from rotating in a state where it can move in the axial direction with respect to the valve housing 10. The lateral width Wa of the non-rotating recess groove 18D is set to be sufficiently larger than the lateral width Wb of the detent band portion 21A (see FIG. 4).
[0021]
A leaf spring member 34 as a pressing means is attached to the upper large-diameter portion 18E of the female screw member 18. The leaf spring member 34 has a ring-shaped substrate portion 34A and three dog-shaped spring piece portions 34B bent up from the ring-shaped substrate portion 34A. As shown in FIG. 2, the leaf spring member 34 is fitted to the outer periphery of the female screw member 18 at the ring-shaped substrate portion 34A and pressed against the step bottom surface 18F of the upper large diameter portion 18E by the lower spring 35 described later. Each of the spring pieces 34B is sandwiched in an elastically deformed state between the anti-rotation concave groove 18D and the anti-rotation belt-like portion 21A (see FIGS. 3 and 4).
[0022]
Due to the spring force of the spring piece portion 34B, as shown in FIG. 4, one groove side surface 18G of the non-rotating concave groove 18D formed on the outer periphery of the female screw member 18 is a non-rotating belt-like portion 21A of the guide member 21. Is pressed against one side surface 21B in advance.
[0023]
As shown in FIG. 1, the upper part of the hollow hole 18 </ b> B of the female screw member 18 is a female screw hole 22. A male screw portion 24 of a male screw member 23 is screwed into the female screw hole 22. The valve spring 20 is a compression coil spring, and is sandwiched between the male threaded portion 24 and the valve body 19 in the hollow hole 18B. The valve body 19 is attached to the female thread member 18 on the valve chamber bottom surface 15 side. It is fast.
[0024]
A lower spring (second spring) 35 formed by a compression coil spring is provided between the step bottom surface 18F (see FIG. 2) of the female screw member 18 and the valve housing 10. The lower spring 35 is given a predetermined spring load and urges the female screw member 18 to the side opposite to the valve chamber bottom surface 15 (upward).
[0025]
The male screw member 23 is integrally formed with a flange portion 25 and an upper shaft portion 23 </ b> A above the male screw portion 24. The upper shaft portion 23 </ b> A passes through a center hole 26 </ b> A (see FIG. 2) of the stationary stopper portion 26 formed by the upper surface portion of the guide member 21, and is a boss portion 52 that is insert-molded at the center portion of the rotor 51 of the stepping motor 50. Is fixedly fitted. The male screw member 23 is fixedly connected to the boss portion 52 of the rotor 51 by this fixed fitting. A can-shaped rotor case 30 is fixed to the upper portion of the valve housing 10 by a lower lid 29, and the rotor 51 and the guide member 21 are accommodated in the rotor case 30.
[0026]
The fixed-side stopper portion 26 is between the female screw member 18 and the boss portion 52 of the rotor 51 as viewed in the axial direction, and as shown in FIG. 26B.
[0027]
The flange portion 25 is closer to the female screw member 18 (lower side) than the fixed-side stopper portion 26, and abuts against a stopper surface 26B on the lower surface side of the fixed-side stopper member 26 with a sliding washer 27 made of high-sliding resin interposed therebetween. Thus, the connecting body of the rotor 51 and the male screw member 23 is prohibited from moving in the axial direction (valve opening direction) opposite to the valve chamber bottom surface 15.
[0028]
As shown in FIG. 1, a spacer 28 is attached to the upper shaft portion 23 </ b> A of the male screw member 23. The spacer 28 is made of a highly slippery resin, is located closer to the boss portion 52 (upper side) than the fixed-side stopper portion 26, contacts the lower bottom surface of the boss portion 52 at the upper end surface, and is formed on the lower end side. The lower surface 28C (see FIG. 2) of the flange portion 28B, which is in contact with the upper surface of the sliding washer 27 at the annular projection 28A (see FIG. 1) and is formed in the middle of the peripheral surface, is the upper surface side of the fixed stopper member 26 By contacting the stopper surface 26A, the connecting body of the rotor 51 and the male screw member 23 is further prevented from moving in the axial direction (valve closing direction) toward the valve chamber bottom surface 15 side.
[0029]
The axial distance between the upper surface of the sliding washer 27 and the lower surface 28C of the flange portion 28B is larger than the plate thickness of the fixed-side stopper portion 26, and the connection between the rotor 51 and the male screw member 23 is relative to the valve housing 10 by the difference. It can move in the axial direction. In other words, the axial movement of the coupling body of the rotor 51 and the male screw member 23 relative to the valve housing 10 is limited to a predetermined range determined by the above-described difference.
[0030]
The boss part 52 has an upper extension shaft part 52A, and the upper extension shaft part 52A is fitted to the bearing member 31 that is engaged with the ceiling in the rotor case 30 so as to be rotatable and movable in the axial direction. A bearing is supported by the bearing member 31. By this bearing support, the center position of the coupling body between the rotor 51 and the male screw member 23 is secured (supported).
[0031]
An upper spring (first spring) 32 formed by a compression coil spring is provided between the flange portion 31 </ b> A of the bearing member 31 and the rotor 51. Upper spring 32 is given a predetermined spring load urges the connected body of the rotor 51 and the male screw member 23 on the side (lower side) of the valve chamber bottom 15, by this, the male screw member 23 rotor 51 and its It is biased toward the valve chamber bottom surface 15 via the boss portion 52 .
[0032]
The rotor 51 is housed in the rotor case 30 and the outer peripheral surface portion is multipolarly magnetized at equal intervals in the circumferential direction. A stator assembly 53 of the stepping motor 50 is mounted on the outer periphery of the rotor case 30. The stator assembly 53 includes an upper and lower two-stage stator coil 54, a plurality of magnetic pole teeth 56, an electrical connector portion 57, and the like, and the positioning piece 58 is engaged with the positioning pin 33 fixed to the valve housing 10. , Circumferential positioning has been performed.
[0033]
Next, the operation of the electric control valve configured as described above will be described.
During the valve closing operation, the coupling body of the rotor 51 and the male screw member 23 rotates in the valve closing direction while the lower surface 28C of the flange portion 28B of the spacer 28 is in contact with the stopper surface 26A on the upper surface side of the stationary stopper member 26. The female screw member 18 and the valve body 19 are lowered (moved in the axial direction toward the valve chamber bottom surface 15 side) by the screw engagement between the male screw portion 24 and the female screw hole 22.
[0034]
Due to this lowering, the needle portion 19B of the valve body 19 closes the valve port 14, and the lowering of the valve body 19 is stopped by the engagement between the needle portion 19 and the valve port 14. Further, when the coupling body of the rotor 51 and the male screw member 23 rotates in the same direction, the female screw member 18 continues to descend.
[0035]
By this lowering, the lower end surface 18A of the female screw member 18 comes into contact with the valve chamber bottom surface 15, and further lowering is restrained. When the connecting body of the rotor 51 and the male screw member 23 further rotates in the same direction, the connecting body of the rotor 51 and the male screw member 23 starts to move upward against the spring force of the upper spring 32.
[0036]
This rise is performed within a predetermined range until the upper surface of the high-sliding washer 27 comes into contact with the stopper surface 26B on the lower surface side of the fixed-side stopper member 26, and the base point is determined at the valve closing point.
[0037]
In the valve closed state, the lower surface 28C of the flange portion 28B of the spacer 28 is separated from the stopper surface 26A on the upper surface side of the fixed stopper member 26. In this state, the coupling body of the rotor 51 and the male screw member 23 is in the valve opening direction. When rotating, first, the coupling body of the rotor 51 and the male screw member 23 moves downward by the screw engagement between the male screw portion 24 and the female screw hole 22.
[0038]
Along with this lowering, the spacer 28 is also lowered, and when the lower surface 28C of the flange portion 28B of the spacer 28 comes into contact with the stopper surface 26A on the upper surface side of the fixed-side stopper member 26, the coupling body of the rotor 51 and the male screw member 23 moves downward. Stop.
[0039]
Furthermore, when the coupling body of the rotor 51 and the male screw member 23 rotates in the same direction, the female screw member 18 starts to rise, and the stepped portion 18C of the female screw member 18 engages with the flange portion 19A of the valve body 19. As a result, the valve element 19 is lifted and opened as the female screw member 18 moves upward.
[0040]
In the valve opening / closing operation described above, the lower spring 35 always acts in the direction of lifting the female screw member 18, and the screw engagement surface (contact surface) between the male screw portion 24 and the female screw hole 22 is one surface, and the screw is twisted. The effect of flow control by (gap) is eliminated. The upper spring 32 acts downward on the coupling body of the rotor 51 and the male screw member 23, and the spring load is immediately applied to the screw engaging portion between the male screw portion 24 and the female screw hole 22 and the female screw member 18 after the rotor is reversed. It acts on the contact portion between the end face 18A and the valve chamber bottom face 15.
[0041]
At the time of reversing the rotor at the base point positioning, the female screw member 18 tries to rotate reversely with respect to the guide member 21. However, due to the spring force of the spring piece portion 34B, one groove side surface 18G of the non-rotating concave groove 18D of the female screw member 18 is guided. Since the inner screw member 18 is pressed against the one side surface 21B of the detent band 21A of the member 21 in advance, the rotation of the female screw member 18 is suppressed, and when the rotor is reversed, the other groove side surface 18H of the detent groove 18D It is avoided in advance that the other side surface 21C collides with force, and that one groove side surface 18G of the rotation-preventing concave groove 18D collides with one side surface 21B of the detent belt-like portion 21A.
[0042]
As a result, no collision noise or vibration is generated when the rotor is reversed such as when the reference point is set, and excellent operational quietness and durability can be obtained.
[0043]
FIG. 5 shows Embodiment 2 of the electric control valve according to the present invention. In FIG. 5, parts corresponding to those in FIG. 1 are denoted by the same reference numerals as those in FIG.
[0044]
The difference between the second embodiment and the first embodiment is that, in the second embodiment, the leaf spring member 34 is omitted, and the screw surface frictional force that prevents the female screw member 18 from being rotationally displaced in the valve opening direction when the valve is closed is inverted. That is, the spring load of the upper spring 32 and the spring load of the lower spring 35 are set so as to act on the screw engaging surfaces of the portion 24 and the female screw hole 22.
[0045]
The optimum setting of the spring load of the upper spring 32 and the spring load of the lower spring 35 will be described with reference to the model diagram shown in FIG.
First, each symbol is defined as follows.
Fu: Spring load of upper spring 32 Fn: Spring load of lower spring 35 P: Drag force between male screw and female screw Q: Force in tangential direction during reversal β: Screw lead angle between male screw portion 24 and female screw hole 22 μm: Screw surface Friction coefficient fm: Friction force of screw surface μh: Friction coefficient fh of main body bottom (valve chamber bottom surface 15) and female screw member 18 Fr: Friction force of main body bottom (valve chamber bottom surface 15) and female screw member 18 N: Bottom of main body (valve Drag Q between the chamber bottom surface 15) and the female thread member 18: horizontal force acting on the female thread
First, consider the balance of forces in the direction perpendicular to the thread surface of the female thread.
P-Fu.cos .beta.-Fn.cos .beta. + Q.sin .beta. = 0 (1)
The frictional force fm generated on the thread surface of the female thread is
fm = μm · P (2)
= Μm (Fu · cosβ + Fn · cosβ−Q · sinβ) (3)
The frictional force fh between the bottom of the main body (valve chamber bottom 15) and the female screw member 18 is:

[0047]
Here, the horizontal force M with the bottom of the main body (valve chamber bottom) acting on the female screw will be considered.
M = fm · cos β−P · sin β ± fh (6)
At this time, when the condition for the female screw to move to the right in FIG.
M> 0
∴fm · cos β-P · sin β-fh> 0 (7)
Substitute equation (5) into equation (7).
fm · cos β−P · sin β− {μh (P · cos β + fm · sin β−Fn)}> 0 (8)
[0048]
Summarize fm.
fm (cosβ-μh · sinβ) -P · sinβ- {μh (P · cosβ-Fn)}> 0 (9)
Substitute equation (2) into equation (9).
μm · P (cosβ−μh · sinβ) −P · sinβ− {μh (P · cosβ-Fn)}> 0 (10)
[0049]
Summarize P.
P (μm · cosβ−μm · μh · sinβ) −P · sinβ−P · μh · cosβ + μh · Fn> 0 (11)
P {(μm−μh) cosβ− (μm · μh + 1) sinβ} + μh · Fn> 0 (12)
Here, in {} of the equation (12),
(Μm−μh) cos β− (μm · μh + 1) sin β = A (13)
And put
P · A + μh · Fn> 0 (14)
[0050]
Furthermore, from equations (2) and (3)
P = Fu · cos β + Fn · cos β−Q · sin β (15)
And substituting this into equation (14),
(Fu.cos.beta. + Fn.cos.beta.-Q.sin.beta.). A + .mu.h.Fn> 0 (16)
It becomes.
Expand and organize this.
Fu · A · cosβ + Fn (A · cosβ + μh) −Q · sinβ · A> 0 (17)
[0051]
Here, the sign of A is obtained.
Assuming A <0, from equation (13):
(Μm−μh) cos β− (μm · μh + 1) sin β <0 (18)
μm−μh− (μm · μh + 1) tan β <0 (19)
Since μm and μh are both coefficients of friction between the resin and the metal, when μm = μh, from μm−μh = 0, the equation (19) is
− (Μm · μh + 1) tan β <0 (20)
Since μm> 0, μh> 0, screw lead angle β = 8.39 °, and tanβ = 0.147> 0, equation (20) is established. Therefore, the assumption of A <0 also holds.
[0052]
Since A <0, equation (17) is
Fu · A · cosβ> Q · sinβ · A-Fn (A · cosβ + μh) (21)
Fu <Q · tan β−Fn (1 + μh / (A · cos β)) (22)
It becomes.
Since this is a condition for the female screw to move in the right direction, the condition for not moving in the right direction is expressed by the following equation (23).
Fu> Q · tan β−Fn (1 + μh / (A · cos β)) (23)
[0053]
As described above, in order to prevent the female screw from moving in the right direction (CCW direction) when the rotor is reversed, the upper spring load Fu may be equal to or greater than the value of Q · tan β−Fn (1 + μh / (A · cos β)).
[0054]
Due to the optimal setting of the spring load of the upper spring 32 and the spring load of the lower spring 35 described above, the thread surface frictional force that prevents the female screw member 18 from being rotationally displaced in the valve opening direction at the time of reversing the valve closed is the male screw portion 24 and the female screw hole. It acts on the screw engaging surface with 22 and the female screw member 18 stops moving when the rotor is reversed.
[0055]
As a result, no collision noise or vibration is generated when the rotor is reversed such as when the reference point is set, and excellent operational quietness and durability can be obtained.
[0056]
【The invention's effect】
As can be understood from the above description, according to the electric control valve of the present invention, the impact sound is generated when the rotor is reversed, such as when the rotor is reversed, by biasing the rotational direction of the female screw member by the leaf spring and by optimizing the spring load. And no vibration is generated, and excellent operational quietness and durability can be obtained.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing Embodiment 1 of an electric control valve according to the present invention.
FIG. 2 is an exploded perspective view of essential parts of Embodiment 1 of the electric control valve according to the present invention.
FIG. 3 is an enlarged front view of an essential part of Embodiment 1 of the electric control valve according to the present invention.
FIG. 4 is an enlarged side view of the main part of Embodiment 1 of the electric control valve according to the present invention.
FIG. 5 is a longitudinal sectional view showing Embodiment 2 of an electric control valve according to the present invention.
FIG. 6 is a calculation model diagram of spring load optimization in Embodiment 2 of the electric control valve according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Valve housing 11 Primary side port 12 Secondary side port 13 Valve chamber 14 Valve port 15 Valve chamber bottom face 18 Female thread member 18D Non-rotating concave groove 19 Valve body 20 Valve spring 21 Guide member 21A Non-rotating belt part 23 Male thread member 25 Flange part 26 Fixed-side stopper 28 Spacer 32 Upper spring (first spring)
34 Leaf spring member 35 Lower spring (second spring)
50 Stepping motor 51 Rotor 52 Boss part 53 Stator assembly

Claims (5)

A valve housing having a valve chamber and a valve port opened in a bottom surface of the valve chamber;
A female screw member that is provided in the valve housing so as to be movable in the axial direction in a non-rotating state, and abuts against the valve chamber bottom surface at one end surface by the axial movement;
The female screw member is provided so as to be movable in the axial direction only within a predetermined range, the valve port is closed by axial movement on the valve chamber bottom surface side, and the valve port is closed by axial movement in a direction opposite to the valve chamber bottom surface. A valve body that opens,
A valve spring that urges the valve body toward the valve chamber bottom surface with respect to the female screw member;
A male screw member screw-engaged with the female screw member;
A stepping motor including a multi-pole magnetized rotor and a stator, wherein the boss portion of the rotor is fixedly connected to the male screw member, and the male screw member is driven to rotate;
Have
The female screw member is prevented from rotating by an axial sliding engagement between a concave groove formed in the axial direction on the female screw member and the fixing member on the valve housing side, and a non-rotating belt-like portion. An electric control valve provided with pressing means for pressing one groove side surface of the concave groove against one side surface of the detent belt-shaped portion between the detent belt-shaped portion and the detent belt-shaped portion. The electric control valve according to claim 1, wherein the pressing means is a spring. The fixing member is a cylindrical rod-shaped guide member having the detent belt-like portions at a plurality of positions in the circumferential direction, and accommodates the female screw member in an axially movable manner, and the concave groove is an outer periphery of the female screw member. The electric control valve according to claim 1, wherein a leaf spring formed on a surface and sandwiched in an elastically deformed state is provided as the pressing means between the concave groove and the detent belt-like portion. A valve housing having a valve chamber and a valve port opened in a bottom surface of the valve chamber;
A female screw member that is provided in the valve housing so as to be movable in the axial direction in a non-rotating state, and abuts against the valve chamber bottom surface at one end surface by the axial movement;
The female screw member is provided so as to be movable in the axial direction only within a predetermined range, the valve port is closed by axial movement on the valve chamber bottom surface side, and the valve port is closed by axial movement in a direction opposite to the valve chamber bottom surface. A valve body that opens,
A valve spring that urges the valve body toward the valve chamber bottom surface with respect to the female screw member;
A male screw member screw-engaged with the female screw member;
And a multi-pole magnetization of the rotor and the stator, the stepping motor for rotating the pre-Symbol male screw member that is fixedly coupled to the boss portion of the rotor,
A first spring that biases the male screw member toward the valve chamber bottom surface via the rotor and the boss portion ;
A second spring that biases the female screw member to a side opposite to the valve chamber bottom surface;
Have
The rotation prevention of the female screw member is performed by the axial sliding engagement between the concave groove formed in the axial direction on the female screw member and the fixing member on the valve housing side, and the rotation-preventing belt-like portion, and the valve is closed and reversed. The spring load of the first spring and the second spring are such that a thread surface frictional force that sometimes prevents the female screw member from rotationally displacing in the valve opening direction acts on the screw engaging surfaces of the female screw member and the male screw member. Electric control valve with spring load set. The electric control valve according to claim 4, wherein the spring load Fu of the first spring and the second spring spring load Fn are set so as to satisfy the following formula.
Fu> Q · tan β-Fn (1 + μh / (A · cos β))
A = (μm−μh) cosβ− (μm · μh + 1) sinβ
Where Fu: spring load of the first spring Fn: spring load of the second spring Q: force in the tangential direction during reversal β: screw lead angle μm: friction coefficient μh of the screw surface: valve housing fixed side and female screw member Friction coefficient

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