JPH07280123A - Solenoid valve - Google Patents

Abstract

PURPOSE:To improve operation characteristics by applying a double structure of magnetic layer and nonmagnetic layer to a bearing member for minimizing slide resistance, and forming an effective magnetic circuit between a moving member and a solenoid. CONSTITUTION:A sintered copper alloy layer is laid between a back metal and a moving core 17 and, therefore, eccentricity is set at such a small value as ranging from 0.07 to 0.17 within the range of the accuracy of the thickness of the layer. Furthermore, a gap formed between the internal surface of a bearing 19 having the layer and the external surface of the core 17 is set at a value between 0.02mm and 0.05mm by a diameter difference, and the layer is internally impregnated with a lubricant. As a result, the core 17 is slidably supported under a fine friction force in an axial direction, and efficiently supplied with a magnetic flux from a yoke 18 via the bearing 19. Also, magnetic resistance is set at a minimum value, while the area of both internal and external surfaces of the bearing 19 being increased, subject to the slide resistance thereof with the core 17 not exceeding the preset threshold value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve which is electrically driven to change the flow rate of lubricating oil or other fluid.

[0002]

2. Description of the Related Art An automatic transmission mounted on an automobile includes a torque converter for transmitting engine output, a transmission having several gear ratios, and a gear ratio that is automatically adjusted according to such output and vehicle speed. It is composed of a hydraulic control unit for controlling.

In a hydraulic circuit provided in such an automatic transmission, the hydraulic pressure is variably set via a solenoid valve at the time of gear shifting, so that the output transmitted from the engine to the output shaft is changed stepwise, whereby the occupant is occupant. The shock given to the engine is reduced, and when the gear ratio falls below a predetermined threshold value, the solenoid valve is closed and the engine output is directly transmitted (locked up) to the output shaft. Reduction of fuel consumption can be suppressed.

FIG. 6 is a diagram showing a configuration example of a conventional solenoid valve.
It is (1). In the figure, at the center of one opening of a substantially cylindrical case 60, a cylindrical member having an outer diameter larger than and equal to the inner diameter of the opening is formed, and an input port 61 is formed in the hollow portion. The casing 62 is provided so as to concentrically project. Further, in the vicinity of one opening of the case 60, an output port 63 is formed as a groove extending the opening in a certain direction. Further, the inner diameter of the hollow portion of the case 60 is increased stepwise from the vicinity of the output port 63 in two steps, and in the increased first inner diameter portion, the outer diameter at one end is equal to the inner diameter. The peripheral guide 64 engages. The outer diameter of the peripheral guide 64 is the case 60
A helical coil 65 is provided in the cylindrical space sandwiched between the outer peripheral side surface of the peripheral guide 64 and the inner side surface of the case 60, which are reduced in a stepwise manner at the portion where the inner diameter of the case further increases. It is inserted. In the hollow portion of the peripheral guide 64, a valve sleeve 66 and an armature 67 are slidably inserted in series on the inner peripheral side surface of the hollow portion.
The top of 7 is fixed to one end of a spring 68. In the cylindrical space sandwiched by the side surface of the spring 68 and the inner peripheral side surface of the coil 65, a stator 69 that accommodates the spring 68 and determines the position of the other end is inserted, and the other side of the case 60 is inserted. By caulking the opening, it is fixed to the opening.

In the solenoid valve having such a structure, the coil 65
Armature 6 when is not electrically driven
7 is pushed toward the input port 62 side by the urging force of the spring 68. Therefore, the tip portion of the valve sleeve 66 blocks the physical communication path between the input port 61 and the output port 63, and the flow of oil or other fluid between these ports is blocked.

When the exciting current is supplied to the coil 65, the value of the exciting current is changed between the armature 67 and the stator 69 via a magnetic circuit formed via the case 60 and the peripheral guide 64. A nearly proportional suction force is given. The armature 67 moves in the direction of the spring 68 together with the valve sleeve 66 when such a suction force is larger than the above-mentioned biasing force, and is displaced to a position where such suction force and biasing force are balanced.

Therefore, the opening amount between the input port and the output port increases substantially in proportion to the exciting current supplied to the coil 65, and control is performed to increase or decrease the fluid pressure between these ports (special feature). Kaihei 3-24382).

FIG. 7 is a diagram showing a configuration example of a conventional solenoid valve.
(2) In the figure, a control valve portion 71 including a fluid control valve directly connected to the output shaft 70 is shown by a dotted line, and its detailed configuration is omitted from the drawing. The solenoid portion that drives the output shaft 70 is housed in a pot-shaped case 72 having a hole formed in the center thereof, and the diameter of the hole is set to a predetermined length by an end plate 73 inserted into the bottom portion of the shaft. It is converted to a small diameter while keeping it in common. A helical auxiliary spring 74 is provided at the center of the bottom portion. A cylindrical sleeve 75, which is made of a non-magnetic material and has a width larger than that of the end plate, is attached to the inner peripheral side surface of the end plate 73 with one end of the sleeve 75 in contact with the case 72. A helical coil 76 is provided in a cylindrical space sandwiched between the inner side surface of the case 72 and the outer peripheral side surface of the sleeve 75. The hollow core sandwiched by the inner peripheral side surfaces of the sleeve 75 is slidable with a movable iron core 77 having a hole formed at one end with an inner diameter slightly larger than the outer shape of the auxiliary spring and a depth shorter than the length of the auxiliary spring. Is installed in. Movable iron core 7
The other end of 7 is formed in a tapered shape, and the tip of the output shaft 70 is planted in the center thereof. The outer peripheral side surface of the output shaft 70 is slidably attached to a bearing 78 provided in the opening of the case 72, and the opening of the case 72 near the bearing 78 is parallel to the vicinity of the other end top of the movable iron core 77. A fixed iron core 79 having a peripheral side surface is formed.

In the solenoid valve having such a structure, the coil 76
Is not driven electrically, the movable iron core 77
Is pressed toward the control valve portion 71 by the urging force of the auxiliary spring 74, but stops at a position where the urging force and the force applied from the control valve portion 71 via the output shaft 70 are in equilibrium, and the fluid valve is closed. Set to the closed state.

When the exciting current is supplied to the coil 76, the value of the exciting current is almost equalized between the movable iron core 77 and the fixed iron core 79 via the magnetic circuit formed via the end plate 73. A proportional suction force is given. The movable iron core 77 moves toward the fixed iron core 79 by such a suction force, and the sum of the suction force and the biasing force of the auxiliary spring 74 and the control valve portion 7 via the output shaft 70 as described above.
It is displaced to a position where it is balanced with the force given by 1.

Therefore, in the control valve section 71, the opening amount of a fluid control valve (not shown) increases substantially in proportion to the exciting current supplied to the coil 76, and control is performed to increase or decrease the fluid pressure.

Incidentally, as a conventional example similar to the solenoid valve according to the present application, in addition to the above-mentioned one, for example, the solenoid portion and the valve portion are isolated via a diaphragm, and the diaphragm and the solenoid portion are separated from each other. By enclosing a high-viscosity fluid in the sandwiched space, the damping force of the solenoid is increased to improve the braking characteristics of the valve, and malfunctions due to impurities are avoided (Japanese Patent Laid-Open No. 3-61775).
There is. Further, Japanese Patent Application Laid-Open No. 3-79880 discloses a leaf spring arranged between a solenoid portion and a valve portion. However, the leaf spring has a hole for obtaining a unique biasing force. Has been done. Therefore, the solenoid portion and the valve portion are not isolated by such a leaf spring.

[0013]

Among such conventional solenoid valves, the one shown in FIG. 6 has a peripheral guide 6 as shown in FIG.
Part of the fluid flowing out from the gap between the valve seat 66 (not shown) and the tip of the valve sleeve 66 that opens and closes in accordance with the operation of the valve flows into the gap between the valve seat 4 and the valve sleeve 66.

However, when the fluid controlled through such an electromagnetic valve contains powder of magnetic material such as wear powder of gears or fine powder mixed during assembly (hereinafter referred to as "magnetic powder"). First, these magnetic powders are attracted to their opposing side walls by the magnetic flux passing between the armature 67 and the peripheral guide 64. Therefore, in such a state, the characteristics of the magnetic circuit described above are changed and the linearity of the opening amount (fluid pressure) with respect to the exciting current of the coil 65 is deteriorated.

Further, when the content of such magnetic powder is extremely large, the armature 67 and the peripheral guide 64 are likely to be fixed due to the adsorption of the magnetic powder, resulting in a fixing failure.

Further, in order to avoid such deterioration of linearity and occurrence of fixing trouble, high accuracy is required for the valve sleeve 66, the peripheral guide 64, and other processing steps, and cost reduction is hindered.

In the conventional example shown in FIG. 7, the movable iron core 7 is used.
The movable portion composed of 7 and the output shaft 70 is cantilevered by the bearing 78, and the driving force for displacing the movable iron core 77 is reduced by the frictional force with respect to the sleeve 75. Therefore, as shown in FIG. 8, the opening amount (fluid pressure) with respect to the value of the exciting current of the coil 76 has a large hysteresis. Further, due to such friction, fine powder is generated from the movable iron core 77 and the sleeve 75, and fine powder contained in the fluid enters through the gap between the bearing 78 and the output shaft 70, so that between the movable iron core 77 and the fixed iron core 79. The amount of contaminants adhering to the surface increased and it was easy for the operating characteristics to change over time.

It is an object of the present invention to provide a solenoid valve capable of maintaining stable performance while improving operating characteristics.

[0019]

According to a first aspect of the present invention, a valve for setting an opening amount of a fluid flow passage and an exciting current are supplied from the outside, and an electromagnetic force is generated according to the exciting current. A solenoid and a movable member, which is made of a ferromagnetic material and has one end connected to the valve, is displaced along the axis of the solenoid by electromagnetic force to drive the valve, and a hollow member of the solenoid which is made of a ferromagnetic material and which is made of a ferromagnetic material. A first fixing member fitted at one end and a space made up of a ferromagnetic material, which is mounted on or fitted at the other end of the hollow portion of the solenoid, allows the movable member to be displaced along the axis. A second fixed member which is formed between the fixed member and has a connection path between one end of the movable member and the valve, and a non-magnetic member which is slidably provided on the outer peripheral surface of the movable member. A non-magnetic layer and a ferromagnetic material laminated on the outer peripheral surface of the non-magnetic layer. And a made magnetic layer, characterized in that a bearing member outer peripheral side surface of the magnetic layer is engaged or those set to the second fixing member.

According to a second aspect of the present invention, there is provided a movable member which is slidably supported along a certain axis, and an electromagnetic force is generated according to an exciting current supplied from the outside to generate the electromagnetic force. A solenoid section for displacing the movable member by means of the solenoid section, a valve section driven by the solenoid section through the movable member to increase or decrease the opening amount of the fluid passage according to the displacement, and a solenoid section provided around the movable member. In a solenoid valve provided with a diaphragm that forms a partition wall of a fluid with the valve portion, the solenoid portion is provided with a communication passage formed between the solenoid portion and a space formed between the diaphragm portion and absorbing a pressure difference. It is characterized by having.

According to a third aspect of the present invention, in the solenoid valve according to the first aspect, the non-magnetic layer forming the bearing portion comprises:
It is characterized in that a lubricant that reduces sliding resistance to the movable member is impregnated or applied.

According to a fourth aspect of the present invention, in the solenoid valve according to the first aspect, the non-magnetic layer forming the bearing portion has a maximum eccentricity that is allowable between the bearing and the movable member. It is characterized by having a thickness equal to or greater than a value obtained by dividing the maximum amount of eccentricity that can occur in between.

According to a fifth aspect of the present invention, in the solenoid valve according to the first aspect, the magnetic layer forming the bearing portion has a hysteresis width of displacement of the movable member with respect to an exciting current that is less than or equal to a desired upper limit value. It is characterized by being made of a ferromagnetic material having a magnetic force.

According to a sixth aspect of the present invention, in the solenoid valve according to the first aspect, the valve body for varying the opening amount of the valve and the movable member are integrally formed. The invention described in claim 7 is the solenoid valve according to claim 2,
The communication passage is extended to the outside of the solenoid portion, the valve portion and the flow passage.

[0025]

In the solenoid valve according to the invention described in claim 1,
When an exciting current is supplied to the solenoid, the solenoid generates a magnetic flux having a density substantially proportional to the value of the exciting current, and the magnetic flux is composed of a first fixed member, a solenoid, a second fixed member, a bearing member and a movable member. Supplied to the magnetic circuit. Such a magnetic flux is supplied to the movable member from the solenoid via the second fixed member and the bearing, and is displaced in accordance with the electromagnetic force attracted toward the first fixed member. Therefore, the valve is driven according to the above-mentioned exciting current, and the opening amount of the fluid flow passage provided with the valve is variably set.

Further, in the process of driving the valve in this way, the above-mentioned magnetic flux is supplied from the second fixed member to the movable member through the magnetic layer and the non-magnetic layer of the bearing member, and the movable member thereof. Is slid while being supported in the axial direction of the solenoid by the non-magnetic layer of the bearing member. However, since the non-magnetic layer is formed of a non-magnetic material, the attractive force generated electromagnetically between the non-magnetic layer and the movable member is small, and the sliding resistance between the two is kept small. Be done. Further, the eccentricity, which indicates the deviation of the shaft center between the bearing member and the movable member, can be suppressed to a smaller value as the thickness of the non-magnetic layer described above increases. The generated electromagnetic force is suppressed.

That is, since the movable member is slidably supported in the axial direction of the solenoid and displaced in proportion to the value of the exciting current, the movable member responds efficiently to the exciting current. As a result, response characteristics with high linearity accuracy and less hysteresis can be obtained.

In the solenoid valve according to the second aspect of the present invention, the diaphragm forms a partition wall between the solenoid portion and the valve portion so that the valve portion increases or decreases the opening amount of the flow passage. Are prevented from entering the solenoid section.

Further, when the movable member is displaced in accordance with the driving of the valve portion according to the exciting current or the temperature of the space sandwiched by the movable member, the solenoid portion and the diaphragm changes significantly, the volume of the space also changes. Similarly, a pressure difference is generated between the solenoid and the solenoid. However, since such a space communicates with the inside of the solenoid through the communication passage, the pressure difference between the two due to the change in volume is absorbed.

That is, fluctuations in the characteristics of the solenoid portion due to intrusion of fluid contaminants are suppressed, and the movable member is faithfully driven by the exciting current applied to the solenoid portion without being blocked by the pressure difference described above. The temperature change and secular change of linearity, hysteresis and other operating characteristics are greatly reduced.

In the solenoid valve according to the third aspect of the present invention, since the lubricant is impregnated or applied to the non-magnetic layer which is in contact with the outer peripheral surface of the movable member, the movable member and the bearing which are displaced in response to the exciting current. The sliding resistance between the parts is reduced.

Therefore, as compared with the solenoid valve according to the first aspect of the present invention, it is possible to obtain operating characteristics with higher linearity accuracy and smaller hysteresis width. In the solenoid valve according to the fourth aspect of the present invention, the thickness of the non-magnetic layer is such that the maximum amount of axial deviation that can occur between the bearing and the movable member depending on the processing accuracy of each of these parts and the The sliding resistance between the magnetic layer and the movable member is set to a value larger than the ratio to the maximum eccentricity, which is the maximum allowable value.

Therefore, by setting the thickness of the non-magnetic layer in consideration of the above-described processing accuracy and allowable sliding resistance, the desired linearity of the operation characteristics can be obtained while adapting to the number of processes and methods involved in processing. And a hysteresis width can be obtained.

In the electromagnetic valve according to the fifth aspect of the present invention, the coercive force and hardness of the ferromagnetic material generally decrease as the amount of carbon contained in the ferromagnetic material decreases, but the magnetic layer has an exciting current. Is composed of a ferromagnetic material having a coercive force such that the hysteresis width of the displacement of the movable member with respect to is less than or equal to a desired upper limit value. Further, as the constituent material of the magnetic layer, it is possible to select a ferromagnetic material having both hardness and magnetic permeability adapted to the ease of work in the assembly process and the vibration absorption characteristics during operation.

Therefore, while avoiding complication of the structure for slidably holding the movable member, it is possible to surely obtain the operation characteristics having a small linearity and a small hysteresis width. In the solenoid valve according to the invention described in claim 6, since the valve body and the movable member are integrally formed, the joining structure required for such integration is not necessary, and the structure is simplified, and the parts are The constant is reduced.

That is, since the restrictions associated with the selection of the constituent materials of the movable member and the valve body associated with such a joint structure are avoided, and the desired mechanical strength is reliably obtained, the cost and size are reduced. Is realized.

In the solenoid valve according to the seventh aspect of the present invention, the pressure between the solenoid portion and the space sandwiched by the movable member, the solenoid portion and the diaphragm can be biased and changed depending on the displacement and temperature of the movable member. However, the pressure deviation is surely absorbed outside the above-mentioned space or the solenoid portion, the valve portion, and the flow passage connected via the communication passage extended from the solenoid portion.

Therefore, the accuracy of the linearity in the operating characteristics can be improved.

[0039]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a diagram showing an embodiment corresponding to the invention described in claims 1 to 7.

In the figure, a case 11 for accommodating a solenoid portion has five different diameters d ₁ , d ₂ , d ₃ , d ₄ , d ₅ (d ₁ ≧ d ₂ ≧ d ₃₎ concentrically from one end to the other end. ≧ d ₄ ≧ d ₅ )
It is composed of a metal cylindrical body that penetrates through a hole formed in a stepwise manner. The opening at the other end of the case 11 has an introduction passage 12 having a diameter d ₆ (<d ₅ ) formed concentrically with a countersink formed with a diameter d ₅ over a predetermined depth. In addition, the valve seat portion 14 having the discharge passages 13 _{11 to} 131 _m that radially penetrates is joined to the inner peripheral side surface of the countersink. In a section from the opening at the other end of the case 11 to the inclined bottom surface of the countersink in the valve seat portion 14, the outer diameter is slightly smaller than d _{5 and} is formed as a tapered tip end engaging with the inclined bottom surface. Has a valve body 15, and the outer peripheral side surface which is slightly separated from the sum of the depths of the countersink and the hole having the diameter d ₅ formed in the case 11 in the axial direction from the front end is constricted in a stepwise manner (hereinafter, The constricted portion is simply referred to as a "groove".) The central portion of the annular diaphragm 16 is engaged, and the diameter of the outer peripheral side surface is d ₇ (d ₂ ≧ d ₇ ≧ d ₅ ) in the axial direction, A movable iron core 17 formed by stepwise changing d ₈ (d ₇ ≧ d ₈ ≧ d ₅ ) is slidably inserted. The outer peripheral portion of the diaphragm 16 engages with the inner peripheral surface of the hole formed in the case 11 with the diameter d ₃ and the bottom portion in the vicinity of the inner peripheral surface (hereinafter, simply referred to as “stepped portion”).
Adjacent to the hole, the bottom of the hole of diameter d ₂ has an outer diameter of d ₅ and is concentric and serial with a diameter of d ₉ (d ₄ ≧ d ₉ ≧ d ₇ ) and d _{7 in} the center. An annular yoke 1 having a hole formed in
8 are stacked. An annular bearing 19 having an outer diameter equal to d ₉ and an inner diameter substantially equal to d ₇ is engaged with a hole formed in the center of the yoke 18 with a diameter d ₉ . Diaphragm 16
Between the space between the inner wall on the other end side of the case 11 and the outer wall surface on the other end side of the case, discharge passages 13 _{21 to} 132 _n penetrating the both are formed at predetermined intervals. It In the section of the hole formed in the case 11 with the diameter d ₂ except for the portion where the yoke 18 is laminated, the pipe 20 having the same length as the section and the inner diameter equal to d ₉ and the outer portion of the pipe Coil that engages the side surface (wrapped on a bobbin made of magnetic material)
21 and 21 are inserted. Movable iron core 17 having an outer diameter of d ₈
A spacer 22 made of a non-magnetic material having the same outer diameter is laminated on the top of the. A hole having a diameter d ₁ formed in the case 11 and a space sandwiched between the inner peripheral side surface of the pipe 20 and the vicinity of the top of the movable iron core 17 have an outer peripheral side surface of the top and a slidable diameter in the center. A hole having a depth corresponding to the movable range along the axis of the portion where the outer diameter of the movable iron core is d ₈ is formed at one end, and a communication hole is formed from the hole to the other end to form the spring 23. A fixed iron core 25 having a communication hole into which the spring bias adjusting screw 24 is inserted in series is engaged. Further, the fixed iron core 25 is attached to the case 11
It is fixed by caulking the peripheral edge of the.

FIG. 2 is a diagram showing the detailed shape and structure of the diaphragm. In the figure, the diaphragm 16
Has a hole formed in the center thereof engaged with a groove of the movable iron core 17, and an outer edge of the stepped portion of the case 11 and the yoke 1.
8 is inserted into the gap sandwiched between the seals 8 and 8 and is arranged as a seal member for separating the space on the side of the yoke 18 and the side of the valve body 15 (the discharge passages 13 _{11 to} 13 _1m , 13 _{21 to} 13 _2n ). Further, the diaphragm 16 includes an introduction path 12 and a discharge path 13 _{11 to} 131 _m ,
The fluid flowing between 13 _{21 and} 13 _2n does not physically or chemically alter the fluid, is capable of smoothly following the displacement of the movable iron core 17 and is deformable, and can be regarded as substantially constant within a predetermined temperature range. It is composed of an elastic member (for example, oil-resistant rubber such as fluorosilicone rubber).

FIG. 3 is a diagram showing a detailed structure around the diaphragm. In the figure, parts having the same functions and configurations as those shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted here.

Holes 31 _{1 to} 31 _M are formed between the inner peripheral surface and the outer peripheral surface of the pipe 20, and the yoke 18 extends from the space between the movable iron core 17 and the diaphragm 16 to the inner peripheral surface of the pipe 20. Communication holes 32 _{1 to} 32 _N reaching the end portions of the side surfaces are formed.

FIG. 4 is a diagram showing a detailed structure of the bearing. In the figure, the bearing 19 is formed of a back metal 31 made of soft iron on the outer peripheral surface side in contact with the inner peripheral surfaces of the yoke 18 and the pipe 20, and the inner peripheral surface of the back metal 41 is impregnated with a lubricant containing Teflon as a main component. The sintered copper alloy layer 42 thus formed is formed to have a thickness of about 0.3 mm.

Regarding the correspondence relationship between this embodiment and claims 1 to 7, the valve seat portion 14, the valve body 15, the introduction passage 1 are shown.
2 and the discharge passage _{13 11 ~13 1m, 13 21 ~13} 2n corresponds to the valve or the valve unit, the pipe 20 and the coil 21 correspond to the solenoid, holes 31 ₁ to 31 _M and the communication holes 32
Other parts except _{1 to} 32 _N correspond to the solenoid portion, the adjusting screw 24, the spring 23 and the fixed iron core 25 correspond to the first fixed member, the movable iron core 17 corresponds to the movable member, and the yoke 18 Corresponds to the second fixing member, the bearing 19 corresponds to the bearing member, and the pipe 20, the holes 31 _{1 to} 31 _M and the communication holes 32 _{1 to} 32 _N correspond to the communication passages.

The operation of this embodiment will be described below with reference to FIGS. When the coil 21 is not electrically driven, the movable iron core 17 is pressed in the direction of the introduction path 12 by the urging force provided by the spring 23, and the tip end portion of the valve body 15 engages with the inclined bottom surface of the valve seat portion 14. It will be in a combined state. Therefore, the introduction path 12 and the discharge paths 13 _{11 to} 13
The flow of the fluid between _{1 m} and 13 _{21 to} 13 _2n is blocked by the valve seat portion 14 and the valve body 15.

When the exciting current is supplied to the coil 21, the fixed iron core 25 forming the magnetic circuit, the side wall of the case 11, the yoke 18, the bearing 19, and the movable iron core 17 are proportional to the value of the exciting current. When excited, the movable iron core 17 is attracted to the fixed iron core 25 side against the biasing force of the spring 23. Therefore, a gap is formed between the valve body 15 and the inclined bottom surface of the valve seat portion 14 with an opening amount that is substantially proportional to the value of the exciting current, and the introduction passage 12 and the discharge passages 13 ₁₁ to 1 1 are formed through the gap.
The flow rate of the fluid between 3 _1m and 13 _{21 to} 13 _2n is variably set.

When the axes of the movable core 17 and the bearing 19 are deviated from each other, generally, an uneven frictional force is generated between the inner peripheral side surface of the bearing 19 and the outer peripheral side surface of the movable iron core 17 to cause an operation. The linearity of the characteristics deteriorates, and a large hysteresis occurs in the operation characteristics. Furthermore, in the state where the exciting current is supplied to the coil 21,

[0049]

[Equation 1]

When the eccentricity ratio given by the equation (7) exceeds 0.7, in general, an electromagnetic attractive force is greatly deviated in a specific direction between the outer peripheral side surface of the movable iron core 17 and the inner peripheral side surface of the bearing 19. To work.

However, in this embodiment, the back metal 41 is used.
And the movable iron core 17 between the sintered copper alloy layer 4 which is a non-magnetic layer
By interposing 2, the above-mentioned eccentricity is "0.07" to "0.17" in the range of accuracy of the thickness of the sintered copper alloy layer.
And set to a small value. Furthermore, the gap formed between the inner peripheral side surface of the bearing 19 on which the sintered copper alloy layer 42 is formed and the outer peripheral side surface of the movable iron core 17 is 0.02 mm to 0.
The thickness of the sintered copper alloy layer 42 is set to 05 mm, and the inside thereof is impregnated with the lubricant as described above.

Therefore, the movable iron core 17 is slidably supported by a slight frictional force in the axial direction of the movable iron core 17 in the above-mentioned displacement process, and the magnetic flux is efficiently supplied from the yoke 18 through the bearing 19. It

The magnetic resistance of the above-mentioned magnetic circuit is set to a minimum value by setting the areas of the outer peripheral side surface and the inner peripheral side surface of the bearing 19 large unless the sliding resistance with the movable iron core 17 exceeds a predetermined threshold value. Can be set to the value of. Therefore, the movable iron core 17 (valve body 15)
The electromagnetic force (solenoid actuating force) for displacing is greatly increased as compared with the conventional example.

Further, the valve body 15 which is displaced in this way
Stops at a position where the sum of the above electromagnetic force and the pressure of the fluid supplied to the introduction path 12 is in balance with the urging force applied from the spring 23. However, as described above, since the solenoid acting force increases as compared with the conventional example, the spring 23
It is possible to set the urging force of the spring larger than that of the conventional example, or to set the ratio of the pressure of the fluid to the urging force of the spring to be small.

Further, the bearing 19 and the fixed iron core 25 are
Since the pipes 20 are individually fitted into the openings at both ends, the axes of the fixed iron core and the movable iron core 17 coincide with each other within the range of the machining accuracy of these iron cores, and the axes of the yokes are the same. Since the axes of 18 also coincide with each other with high accuracy, the above-mentioned magnetic circuit is formed with high accuracy and uniformly in all directions centering on these axes.

Therefore, according to the present embodiment, it is possible to obtain a good linearity by suppressing the variation of the operating characteristics according to the pressure of the fluid while achieving the miniaturization, and the width of the hysteresis is greatly reduced.

[0057] Further, in this embodiment, the introduction passage 12, a valve unit comprising a discharge channel _{13 11 ~13 1m, 13 21 ~13} 2n, the valve seat 14 and the valve body 15, a solenoid portion consisting of the other part It is isolated via the diaphragm 16. Therefore, the fluid passing through the valve portion is prevented from flowing into the solenoid portion, and the contaminants of the fluid do not narrow the gap between the movable iron core 17 and the bearing 19.

Furthermore, when the movable core 17 is displaced, the movable core, the diaphragm 16 and the yoke 18 are moved.
The volume of the space sandwiched between and the space sandwiched between the movable iron core 17, the fixed iron core 25, the pipe 20, and the bearing 19 slightly changes. However, these spaces are the communication holes 32 ₁
.About.32 _N and the pipe 20 and the bearing 19 communicate with each other through a gap, and the holes 31 _{1 to} 31 _M , the outer peripheral side surface of the pipe 20 and a coil 21 communicate with the outside of the case 11.

Therefore, the generation of a force acting on the movable iron core 17 is avoided by the pressure difference caused by the change in the volume of the two spaces described above, and the movable iron core 17 is freely displaced without being blocked by such a force. Further, in these spaces, since the above-mentioned change in volume is small, the amount of ventilation with the outside is also small, and there is no possibility that fine dust or the like will be sucked from the outside of the case 11.

Thus, according to this embodiment, the movable iron core 1
The smooth displacement of No. 7 is guaranteed, the linearity of the operating characteristics is maintained, and the occurrence of secular change and failure is avoided. In the present embodiment, the fixed core 2 that engages with the top of the movable core 17
By making the outer shape near the opening of 5 a tapered shape, the non-linearity of the change in electromagnetic force with respect to the distance between the two is compensated,
Also, by attaching the spacer 22 to the top of the movable core, the movable core is displaced to the closest point of the fixed core 25, and deterioration of response characteristics that may occur due to the electromagnetic force exceeding a predetermined upper limit is avoided. However, the present invention is not limited to such a configuration, and if the desired electromagnetic force is surely obtained,
You may apply some stopper mechanism which limits the minimum space | interval of the movable iron core 17 and the fixed iron core 25.

Further, in this embodiment, the valve body 15 is integrally molded at the tip of the movable iron core 17, so that the number of parts is reduced without complicating the structure, and the number of assembling steps is reduced and the cost is reduced. However, the present invention is not limited to such a configuration, and has sufficient durability against the required physical environment, chemical environment and thermal environment as shown in FIG. 5, for example. Alternatively, the valve body 51 may be formed of a member, and the valve body may be integrated with the individually formed movable iron core 52 by press fitting, brazing, or other method of joining.

Further, in the present embodiment, the movable iron core 17, the yoke 18, the fixed iron core 25 and the back metal 41 are made of iron or soft iron, but the present invention is not limited to such iron material, and a desired transparent material. Any ferromagnetic material may be used as long as the magnetic susceptibility, coercive force, hardness and other characteristics can be reliably obtained.

Further, in the present embodiment, the magnetic circuit is formed through the yoke 18 which is a member separate from the fixed iron core 25, but the present invention is not limited to such a constitution, and sufficient machining accuracy is obtained. If the above is obtained, for example, the yoke 18 may be integrally formed with the case 11, or the yoke 18 may be integrally formed as a magnetic core of the coil 21.

Further, in the present embodiment, the movable iron core 17 slides with the bearing 19 on the outer peripheral side surface having the largest outer diameter, but the present invention is not limited to such a structure, and the movable iron core is displaced. The outer diameter of the movable iron core may be constant, or the outer diameter of the portion that slides with the bearing 19 may be smaller than that of the other portion as long as it is stably supported while maintaining the shaft.

In the present embodiment, the movable iron core 17 (5
Although the outer peripheral side surface of 2) is not treated at all, it is possible to reduce sliding resistance with the bearing 19 by, for example, performing nitriding or other surface hardening treatment or coating a hard layer. It is also possible to increase durability.

Further, in the present embodiment, the movable iron core 17 and the valve body 15 are integrated, but the present invention is not limited to such a configuration, and for example, a wire or the like for transmitting the displacement of the movable iron core 17 The valve body may be displaced or the opening amount of the valve may be changed via the transmission mechanism.

Further, in the present embodiment, the movable iron core 17 is braked through the helical spring 23, but the present invention is not limited to such a configuration, and the movable iron core is displaced. If a predetermined urging force is surely obtained in, a leaf spring, an air spring, a hydraulic spring or any other urging member may be used.

Furthermore, in the present embodiment, the present invention is applied to the poppet valve, but the present invention is characterized by the structure of the solenoid portion and the portion that partitions the solenoid portion and the valve portion. If such a structure can be applied, it can be applied to any valve.

In this embodiment, the diaphragm 16,
A space sandwiched by the movable iron core 17 and the yoke 18 is formed in the yoke, and the communication holes 32 _{1 to} 31 _N , the space inside the pipe 20, the holes 31 _{1 to} 31 _M , the pipe 20 and the coil 2 are formed.
However, the present invention is not limited to such a structure of the communication passage, and for example, a hole formed on the outer surface or inside of the yoke 18 and its A communication passage may be formed by a hole formed by connecting the case 11 to the hole. Furthermore, the pressure of the space sandwiched by the diaphragm 16, the movable iron core 17, and the yoke 18,
When an error in the operating characteristics due to the bias of the complementarity with the pressure in the space sandwiched between the fixed iron core 25 and the movable iron core 17 is allowed, the connection from the holes 31 _{1 to} 31 _M to the outside of the case 11 is allowed. There may be no passage section.

[0070]

As described above, according to the present invention, the bearing member that supports the movable member so as to be slidable in the axial direction has the double structure including the magnetic layer and the non-magnetic layer, so that the sliding resistance is increased. By forming an efficient magnetic circuit between the movable member and the solenoid while minimizing the above, and by connecting a space between the diaphragm and the solenoid and the solenoid with a communication path. The pressure difference between the movable member and the movable member caused by the change in temperature and the change in temperature is reduced.

That is, the amount of displacement of the movable member with respect to the exciting current is increased to suppress the occurrence of hysteresis due to the above-mentioned sliding resistance, and the operating characteristics are as follows: adherence of fluid contaminants and the above-mentioned pressure difference. The accompanying linearity error and aging change are prevented.

Therefore, in the solenoid valve to which the present invention is applied, the performance and reliability can be improved while the cost and the size are reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment corresponding to the invention described in claims 1 to 7.

FIG. 2 is a diagram showing a detailed shape and structure of a diaphragm.

FIG. 3 is a diagram showing a detailed structure around a diaphragm.

FIG. 4 is a diagram showing a detailed configuration of a bearing.

FIG. 5 is a diagram showing another configuration example of a movable iron core and a valve body.

FIG. 6 is a diagram (1) showing a configuration example of a conventional solenoid valve.

FIG. 7 is a diagram (2) showing a configuration example of a conventional solenoid valve.

FIG. 8 is a diagram illustrating a problem of a conventional example.

[Explanation of symbols]

 11 Case 12 Inlet Path 13 Discharge Path 14 Valve Seat 15,51 Valve Body 16 Diaphragm 17,52,77 Movable Iron Core 18 Yoke 19 Bearing 20 Pipe 21,65,76 Coil 22 Spacer 23,68 Spring 24 Adjusting Screw 25,79 Fixed core 31 Hole 32 Communication hole 41 Back metal 42 Sintered copper alloy layer 60, 72 Case 61 Input port 62 Casing 63 Output port 64 Peripheral guide 66 Valve sleeve 67 Armature 69 Stator 70 Output shaft 71 Control valve section 73 End plate 74 Auxiliary Spring 75 Sleeve 78 Bearing

Claims (7)

[Claims] 1. A valve for setting an opening amount of a fluid flow passage, a solenoid which is supplied with an exciting current from the outside and generates an electromagnetic force in accordance with the exciting current, and a solenoid which is made of a ferromagnetic material and has one end thereof. A movable member that is connected to the valve and is displaced along the axis of the solenoid by the electromagnetic force to drive the valve; and a first member that is made of a ferromagnetic material and that is inserted into one end of the hollow portion of the solenoid. A space between the fixed member and the first fixed member, which is made of a ferromagnetic material, is attached to or fitted into the other end of the hollow portion of the solenoid, and the movable member can be displaced along the axis. A second fixed member having a connecting path between one end of the movable member and the valve, and a non-magnetic member formed of a non-magnetic material and slidably provided around the outer peripheral surface of the movable member. A ferromagnetic material is laminated on the outer peripheral side surface of the magnetic layer and its non-magnetic layer. And a magnetic layer formed Te, solenoid valve, characterized in that a bearing member engaged or those set to the second fixing member outer peripheral side surface of the magnetic layer. 2. A movable member, which is slidably supported along a fixed axis, generates an electromagnetic force according to an exciting current supplied from the outside, and displaces the movable member by the electromagnetic force. A solenoid section; a valve section driven by the solenoid section through the movable member to increase or decrease the opening amount of the fluid flow passage according to the displacement; and the solenoid section and the valve provided around the movable member. And a diaphragm that forms a partition wall of the fluid between the solenoid section and the diaphragm, the solenoid section being formed between the solenoid section and a space formed between the diaphragm and the solenoid section. A solenoid valve with a passage. 3. The electromagnetic valve according to claim 1, wherein the non-magnetic layer forming the bearing portion is impregnated or coated with a lubricant that reduces sliding resistance to the movable member. valve. 4. The solenoid valve according to claim 1, wherein the non-magnetic layer forming the bearing portion has a maximum eccentricity that can be generated between the bearing and the movable member at a maximum allowable eccentricity. A solenoid valve having a thickness equal to or greater than a value obtained by dividing the amount. 5. The solenoid valve according to claim 1, wherein the magnetic layer forming the bearing portion is made of a ferromagnetic material having a coercive force such that a hysteresis width of displacement of the movable member with respect to an exciting current becomes a desired upper limit value or less. Solenoid valve characterized by becoming. 6. The solenoid valve according to claim 1, wherein a valve body for varying an opening amount of the valve and a movable member are integrally formed. 7. The solenoid valve according to claim 2, wherein the communication passage is extended to the outside of the solenoid portion, the valve portion and the flow passage.