Solenoid valve structure

Description

I0204062 / FC-EFA DESCRIPTION

[0001] The present invention relates to the sector 5 of the solenoid valves and refers, in particular, to an armor and a method of producing such armor for solenoid valves.

[0002] In the known art there are solutions of solenoid valves having a magnetic circuit in which 10 induces the magnetic field produced by a coil. The magnetic circuit must be designed to facilitate fluid sealing with other components of the solenoid valve to avoid fluid leaks even when the solenoid valve operates at high pressures. 15 An example of a prior art solenoid valve is shown in figures 1a and 1b.

[0003] One of the problems of these types of solenoid valves is that the magnetic circuit, being made by coupling different elements 20 ferromagnetic, form air gaps which, together with the need to create leak-proof interfaces with others valve components, generate zones of dispersion of magnetic field lines.

[0004] A further problem that arises from the 25 Complexities of the Solenoid Valve Magnetic Circuit of the known art is the consequent complexity of the system of sealing that must necessarily adapt to the numerous interface surfaces that are created between the components once the solenoid valve is assembled. 5

[0005] For example, in the solenoid valve of the figures 1a and 1b, the magnetic circuit is formed by a coil 3020 made up of a thread wound on a spool 3210, a 3026 armature magnetically coupled to the coil 3020, a fixed core 3024 arranged coaxially to the 10 coil 3020, a movable core 3022, also arranged coaxially to the 3020 coil, and a pole piece 3266 separate from the 3026 armature. The circuit magnetic of the solenoid valve of the prior art is operationally connected to the valve body 3001. 15

[0006] With reference to figures 1a and 1b, the solenoid valve of the prior art has a system of seal composed of three sealing rings, also called “O- ring”. The first sealing ring 3310 is positioned between the 3266 pole piece and the pneumatic valve body 20 3001, the second sealing ring 3312 is positioned between the pole piece 3266 and the spool 3210 and the third sealing ring 3314 is positioned between the fixed core 3024 and the spool 3210.

[0007] Therefore, also taking into account the fact 25 that many applications require solenoid valves always more miniaturized, it is evident that the solenoid valves of the known art suffer from some limitations related to the efficiency of the magnetic circuit and the difficulty in the manufacturing and assembly of components 5 of the valve.

[0008] The purpose of the present invention is to propose a solenoid valve, a circuit armature magnetic and its production method, capable of overcome at least in part the drawbacks of art 10 note above complained.

[0009] This goal is achieved by a solenoid valve according to claim 1, an armature for such a solenoid valve according to the Claim 10 and a related production method 15 according to claim 12.

[00010] Additional features and benefits of the invention will appear from the description below reported of his favorite examples of realization, data for indicative purposes only and not limited to, with reference to 20 to the attached figures, in which:

[00011] – Figures 1a and 1b show respectively a perspective view and a section view of a prior art solenoid valve;

[00012] – Figure 2 shows a split view 25 of the components of a solenoid valve according to the invention;

[00013] – figure 3 is a perspective axial section of the solenoid-armature group according to the invention, in which highlights the three levels in which they extend 5 the head, side and base portions of the armor;

[00014] – figure 4 is a perspective axial section of a solenoid valve according to one embodiment of the invention;

[00015] – figure 5 is another perspective view, in 10 partial section, of the solenoid valve according to the invention;

[00016] – Figure 6 is a sectional view of the solenoid valve according to the invention;

[00017] – Figure 7 is a perspective view in 15 partial section of the solenoid valve according to the invention;

[00018] – Figure 8 is an enlarged axial section of the solenoid valve portion at of the engagement between the armature and the fixed core and between the 20 fixed core and the mobile core;

[00019] – Figure 9 shows a sequence of phases of the method of producing an armor for the solenoid valve according to the present invention.

[00020] With reference to the attached figures, with 25 the number 900 indicates a solenoid valve according to the invention as a whole.

[00021] The solenoid valve 900 comprises a body valve 1 in which pneumatic connections are obtained 1000 and a 100 valve seat. 5

[00022] According to one embodiment, the seat valve 100 connects fluids alternatively at least two of the connections pneumatic. In fact, the valve seat 100 allows the retention or leakage of the contained fluid 10 inside the valve body 1 when this is closed or open respectively.

[00023] Furthermore, in the valve body 1, a valve body cavity 10.

[00024] According to one embodiment, the cavity 15 of valve body 10 has a substantially shape cylindrical and is obtained around the valve seat 100. Consequently, the valve body cavity 10 is internally delimited by a lateral surface 12 cylindrical. 20

[00025] Furthermore, the solenoid valve 900 includes a control unit 2 operationally connected to the valve body 1. As detailed in the following the description, the control unit 2 allows you to control the operation 25 of the solenoid valve 900 determining its opening and closure.

[00026] The drive assembly 2 comprises a coil 20 to generate a magnetic field.

[00027] The coil 20 is made up of a wire wound on 5 a spool 210. According to one embodiment, the spool includes power terminals for supply the supply current to coil 20. In fact, in order for coil 20 to generate the magnetic field necessary for the operation of the solenoid valve, that is 10 to the movement of the moving core, the coil 20 must be traversed by the supply current. Therefore, the power terminals allow you to supply the supply current to coil 20 necessary for the generation of the magnetic field. 15

[00028] Preferably, the power supply thermals They are faston terminals made of an alloy based on copper and aluminum.

[00029] The coil 20 extends around an axis Y-coil 20

[00030] The coil 20 locates a central seat 200 coaxial with the coil Y axis.

[00031] As can be seen in figure 3, according to a embodiment, the coil 20 extends around to the coil Y axis in a circular manner identifying a 25 headquarters 200 equally circular. In other words, both the coil and the central seat have a circular cross-section.

[00032] The drive assembly 2 comprises a core fixed 24 arranged coaxially to the coil 20. 5

[00033] As shown in figure 2, according to a form of realization, the fixed core 24 has a shape substantially cylindrical so as to be arranged inside the headquarters 200 circular. Furthermore, the fixed core 24 develops axially between a first 10 contact ends 240 and a second end of interaction 241. The fixed core 24 is made of ferromagnetic material to be influenced by the magnetic field generated by coil 20.

[00034] Furthermore, the drive assembly 2 comprises 15 a mobile core 22 arranged coaxially to the coil 20.

[00035] As shown in figure 2 by way of for example, the mobile nucleus 22 has a shape substantially cylindrical so as to be 20 arranged inside the central office 200 circular. Furthermore, the moving core 22 is made of material ferromagnetic to be influenced by the field magnetic generated by coil 20.

[00036] According to one embodiment, the core 25 mobile 22 is axially translatable between a first valve seat closing position 100 and a second opening position of the valve seat 100. In fact, the magnetic field generated by coil 20 when the supply current flows through it 5 interacts with the ferromagnetic material of the nucleus mobile causing a translation along the axis Y coil between a first seat closing position valve 100 and a second opening position of the valve seat 100. 10

[00037] According to one embodiment, the solenoid valve 900 which is the subject of the present invention it is a “normally closed” solenoid valve, that is, in absence of magnetic field generated by coil 20, the mobile core is pushed against the valve body 1 15 causing the valve seat 100 to close. A once the coil is powered by the current power supply, generates the magnetic field that determines the translation of the mobile nucleus 22 towards the fixed nucleus 24. Therefore, according to this embodiment, the 20 first position of the mobile nucleus 22 corresponds to the closing position of the valve seat 100, while the second position of the noble mobile 22 corresponds to the valve seat opening position 100.

[00038] The drive assembly 2 comprises a 25 armor 26 made of ferromagnetic material.

[00039] The armature 26 is magnetically coupled to the coil 20 so as to close the field lines of force magnetic generated by coil 20. In other words, armor 26 allows to convey the lines of force 5 of the magnetic field on the moving core 22 and on the core 24 fixed present inside the central office 200.

[00040] The armor 26 comprises a head portion 260 which extends in one direction substantially transverse to the coil Y axis. Furthermore, 10 the armor 26 comprises a lateral portion 262 which is extends in a substantially parallel direction with respect to the coil axis Y. The armature 26 comprises also a portion of base 264 which extends into a direction substantially transverse to the axis 15 Y coil opposite the head portion 260. In other words, as shown by way of example in figure 2, the armor 26 has a “C” shape in which the portion the base and the head portion are parallel to each other them and connected by the lateral portion which, 20 consequently, it is perpendicular to the said base and head portions.

[00041] According to one embodiment, called base portion 264 is operatively coupled to the body valve 1. 25

[00042] According to one embodiment, a axial through opening 2640 is obtained in the portion of base 264. According to this embodiment, in the axial through opening 2640 is partially the mobile core 22 is housed and slides. 5

[00043] The drive assembly 2 also comprises a 266 pole piece surrounding the moving nucleus 22 in order to increase the interface surface between the mobile core 22 and the field flux lines magnetic. 10

[00044] According to one aspect of the invention, the 266 pole piece is made in a single body with the base portion 264 of the armature 26. In other words, the polar expansion 266 is integrated into the base portion 264 of the armature 26 thus obtaining a 15 single body.

[00045] According to a preferred embodiment, the polar expansion 266 is machined from a single piece body with the base portion 264 of the armature 26.

[00046] The 266 pole piece allows for 20 maximize the cylindrical exchange surface of the base portion between the field lines of force magnetic and the moving nucleus. Therefore, the expansion polar 266 allows you to optimize the magnetic field produced by the coil and, consequently, of 25 increase the overall pulling force with which the core mobile is engaged to determine the opening of the valve seat 100.

[00047] The realization of a single piece It allows you to obtain a series of advantages. First of all 5 place, make the polar expansion of piece in a single body with the base portion means reducing significantly reduce production times as it is possible obtain the finished piece through progressive molding starting from a piece of sheet metal. Furthermore, the process 10 realization is easier to do with a significant reduction in production costs as well.

[00048] Secondly, the realization of piece in a single body of the polar expansion allows to eliminate discontinuity surfaces that would be created 15 if the base portion and the polar expansion were, for example example, joined by welding. The elimination of discontinuity surface also confers advantages in terms of maximizing the field effect magnetic generated by the coil as mentioned above 20 discontinuity surfaces would cause a deviation of the magnetic field lines resulting in a dispersion with consequent loss of efficiency of the solenoid valve since the movement of the moving core inside the coil is 25 altered.

[00049] Furthermore, the process of making piece in a single body of the polar expansion with the basic portion allows to simplify considerably the solenoid valve sealing system. 5

[00050] Figures 1a and 1b show a solenoid valve of the prior art in which the sealing system involving the coil is composed of three sealing rings 3310, 3312, 3314 or gaskets. The first sealing ring 3310 allows for a tight coupling of the 3266 pole piece 10 with valve body 3001, the second sealing ring allows for a tight coupling of the 3266 pole piece and the spool 3210 and the third sealing ring 3314 allows the fixed core 3024 to be sealed together with the 3210 spool. 15

[00051] Therefore, making of piece in a body unique polar expansion with the base portion allows to reduce the number of sealing rings by passing from a three-ring sealing system to a system of two sealing rings, as will be detailed 20 described below. Reduce the areas subject to any losses means significantly increasing the efficiency and performance of the solenoid valve as it is the pressure remained substantially constant creates inside the solenoid valve and the translation 25 of the mobile nucleus does not undergo alterations.

[00052] Furthermore, the reduction in the number of rings of sealing used in the solenoid valve also allows for improve contact between the head portion of the armor and the fixed core. 5

[00053] According to one embodiment, the head portion 260 is placed in direct contact with the first contact end 240 of the fixed core 24 in such that the distance between the head portion 260 and the fixed nucleus 24 is essentially nothing, that is 10 the distance is reduced to the minimum possible distance obtainable by placing two surfaces of two bodies in contact different ones made with the same material. A distance essentially nothing is necessary for a correct operation of the solenoid valve. In particular, 15 minimize the distance between the head portion of the armor and the fixed core allows to increase the shooting force. In contrast, for example, a distance of the order of 0.05-0.1 mm, causes a decrease in the 40% of the pulling force compared to the correct condition 20 contact, that is, the condition in which the distance between the armor and the fixed core is essentially nothing. In fact, this technical feature of distance essentially nothing can be achieved afterwards to the elimination of a sealing ring of the system 25 held, as described above.

[00054] According to one embodiment shown in example title in figure 6, the polar expansion 266 has a pole piece 2660 that is inserts at least partially into the body cavity 5 valve 10 obtained in the valve body 1 around the valve seat 100. According to this embodiment, the lateral surface 12 cylindrical which delimits laterally the valve body cavity 10 and the end of polar expansion 2660 jointly form a 10 annular seat 300 in which a first ring of seal 310. Therefore, the first sealing ring 310 allows the valve body 1 and the armor 26.

[00055] According to one embodiment, the assembly 15 of pilot 2 comprises a hollow tubular element 268 arranged coaxially in the central seat 200 so to accommodate at least the mobile core 22. Preferably, the tubular member 268 has a substantially cylindrical shape so as to be 20 arranged coaxially in the central seat. In other words, the tubular element 268 is coupled to the seat central 200 by means of a shape coupling so that such tubular element 268 is in contact with the spool on which the thread that forms the coil is wound 25 20. Therefore, the tubular element 268 is interposed between the coil spool and the moving core 22 allowing for better translation of the mobile core 22.

[00056] In fact, the tubular element 268 allows for 5 optimize the effect of the magnetic field for move the moving core of the solenoid valve. Furthermore, the tubular element contributes to the effect of pneumatic seal together with the sealing rings that They constitute the sealing system of the solenoid valve. 10

[00057] According to one embodiment, tubular member 268 has a tubular member base 2680 which extends between the polar expansion 266 and the valve body 1. Preferably, the element base tubular 2680 extends radially to the Y coil axis 15 towards and near the lateral surface 12 cylindrical.

[00058] According to this embodiment shown in example title in figure 6, the element base tubular 2680 forms together with the surface 20 lateral 12 cylindrical and at the end of expansion polar 2660 an annular seat 300 in which the first sealing ring 310. Therefore, according to this form of realization, the first sealing ring 310 allows to seal the valve body 1, the element 25 tubular 268 and the armor 26.

[00059] According to one embodiment, the pole piece end 2660 has a shape substantially truncated conical. Therefore, according to this embodiment, the first sealing ring 310 5 engages the truncated conical lateral surface of the pole piece end 2660.

[00060] According to one embodiment, in the core mobile 22, houses an elastic element 220 which engages the fixed core 24 at the 10 second end of interaction 241 so as to maintain elastically the mobile core 22 in the position of closure.

[00061] According to a preferred embodiment, the elastic element 220 is a cylindrical spring. The spring 15 cylindrical, unlike, for example, a spring conical, has a greater axial bulk than allows the pushing action of the moving core against the fixed core when the solenoid valve is in the open configuration. 20

[00062] According to one embodiment, the core fixed 24 is housed in a sealed box in the central seat 200 detected by coil 20 via a second sealing ring 312.

[00063] The solenoid valve according to this 25 invention allows to reduce the number of rings of seals necessary for correct functioning, i.e. three sealing rings in solenoid valves of the prior art two sealing rings in the solenoid valve according to the present invention. In particular, as can be seen 5 comparing figure 4 with figure 1b relating to a solenoid valve of the prior art 4, the realization of the polar expansion integrated into the base portion of the armor allows to eliminate the sealing ring present between the polar expansion, not integrated in the 10 base portion, and the spool suitable to support the coil. The elimination of this third sealing ring allows to simplify the structure and mechanics of the coil because, in fact, a ring of seal positioned between the spool and the expansion 15 polar.

[00064] According to a second embodiment, the fixed core 24 is housed tightly in the element tubular through the second sealing ring 312. 20

[00065] Therefore, the introduction of the element tubular allows to improve the translation of the mobile nucleus inside the headquarters detected by the coil by decreasing the friction force presents between the coil and the moving core. Furthermore, 25 the introduction of the tubular element allows for reduce the number of sealing rings in such a way to significantly reduce air leaks and, consequently, to keep the pressure unchanged generated inside the solenoid valve. 5

[00066] Furthermore, the introduction of the element tubular allows you to move the seals of the solenoid valve from the coil wound on the spool at the ends of the tubular element. In fact, according to the present invention, the first sealing ring is 10 compressed, due to the polar expansion achieved of piece with the base portion of the armor, on the valve body seat.

[00067] The solenoid valve according to the invention allows to significantly improve the efficiency of the 15 magnetic circuit made of one piece in a single body the polar expansion with the base portion of the armor and consequently reducing both the number of components both the interface surfaces and they would deviate the lines of force of the field 20 magnetic. Therefore, the solenoid valve according to the invention has a greater reliability than operation. The reduction of the components that constitute the solenoid valve according to the invention allows to reduce production costs and 25 assembly.

[00068] The present invention also includes a 26 armature for solenoid valve 900.

[00069] The 900 armor comprises an armor body made of ferromagnetic material. 5

[00070] According to one embodiment, the body armor comprises a head portion 260 which is extends in a close-up armor 500, a portion of base 264 extending into a second floor armor 600 parallel to the first floor armor 500 and at least one 10 lateral portion 262 which extends between the portion of head 260 and the base portion 264 in a third plane 700 armor substantially orthogonal to the first floor 500 armor and on the second floor 600 armor.

[00071] According to a preferred embodiment, 15 the body armor comprises a head portion, a base portion and a lateral portion to form a “C” shaped armor.

[00072] According to the present invention, in the portion of base 264, an axial through opening is obtained 20 2640.

[00073] According to the present invention, the portion of base 264, around the axial through opening 2640, It has a thickening of a truncated conical shape suitable for to achieve a polar expansion 266. 25

[00074] According to one embodiment, the pole piece 266 is made of one piece in a body unique with the base portion 264.

[00075] According to one embodiment, the body The armor is made from a single piece. Preferably, the body 5 armor is made from a single piece of a single body.

[00076] The present invention also includes a method of producing an armor 26 for solenoid valve 900 having an armature body made of a piece in a single body. 10

[00077] The method comprises the following steps: a) prepare a sheet metal 6 having a shape substantially rectangular; b) progressively deform at least a portion of sheet metal corresponding to the base portion 264 so 15 to obtain the suitable truncated-conical thickening to achieve polar expansion 266; c) further deform the base portion 264 in so as to create the through axial opening 2640; d) fold the sheet metal 6 so as to define the portion 20 of head 260, the lateral portion 262 and the portion of base 264.

[00078] According to one embodiment, step b) of deformation to obtain the polar expansion 266 is obtained by means of a first punch 2600. 25 Preferably, the first punch 2600 comprises a female portion 2601 so that the portion female 2601 can be positioned in correspondence with the base portion 264 of the armature 26 to make polar expansion 266. 5

[00079] According to one embodiment, step c) of deformation of the base portion to obtain the through axial opening 2640 is obtained by means of a second punch 2700. Preferably, the second punch 2700 includes a male portion 2701 in 10 such that the male portion 2701 is positionable at the base portion 264 of the armor 26 to create the through axial opening 2640.

[00080] According to one embodiment, step d) 15 of sheet metal bending 6 is obtained by means of a 2800 bending tool suitable for conferring the “C” shape to the armor.

[00081] According to one embodiment, the method The production of an armor includes the following stages: 20 b1) create a first folding line that defines the base portion; b2) create a second folding line that defines the lateral portion and the head portion.

[00082] According to a preferred embodiment, 25 the progressive deformation of the sheet metal is obtained by means of a progressive moulding method, i.e. a type of molding that allows you to obtain any face of the armor needed for the correct coupling of the solenoid valve by means of a single 5 sequence of phases.

[00083] It is clear that a technician in the sector, in order to meet contingent needs, could bring modifications to the invention described above, all contained within the scope of protection as defined by the 10 following claims.

Claims

1. Solenoid valve (900) comprising: - a valve body (1) in which pneumatic connections (1000) are obtained and a valve seat (100), in which said valve seat (100) puts at least two of said pneumatic connections into fluid communication alternately; - a pilot assembly (2) operatively connected to the valve body (1) and comprising: - a coil (20) for generating a magnetic field, said coil (20) extending around a coil axis (Y) and identifying a central seat (200) coaxial with said coil axis (Y); - a mobile core (22), arranged coaxially with the coil (20), made of ferromagnetic material to be influenced by said magnetic field, and axially translatable between a first closing position of the valve seat (100) and a second opening position of the valve seat (100); - a fixed core (24), arranged coaxially to the coil (20), made of ferromagnetic material to be influenced by said magnetic field;an armature (26) made of ferromagnetic material and magnetically coupled to the coil (20) so as to close the lines of force of the magnetic field generated by the coil (20); wherein said armature (26) comprises a head portion (260) extending in a substantially transverse direction to the coil axis (Y), a lateral portion (262) extending in a substantially parallel direction to the coil axis (Y) and a base portion (264) extending in a substantially transverse direction to the coil axis (Y) opposite to the head portion (260), wherein said base portion (264) is operatively coupled to the valve body (1), in the base portion (264) being obtained an axial through opening (2640) in which the mobile core (22) is partially housed and slides;wherein the drive assembly (2) further comprises a pole piece (266) surrounding the moving core (22) so as to increase the interface surface between the moving core (22) and the magnetic field flux lines, characterised in that the pole piece (266) is machined integrally with the base portion (264) of the armature (26).; 2. Solenoid valve (900) according to claim 1, wherein the pole piece (266) has a pole piece end (2660) that fits at least partially into a substantially cylindrical valve body cavity (10) formed in the valve body (1) around the valve seat (100), said valve body cavity (10) being internally delimited by a cylindrical lateral surface (12), and such that said cylindrical lateral surface (12) and pole piece end (2660) jointly form an annular seat (300) in which a first sealing ring (310) is housed.

3. Solenoid valve (900) according to claim 1 or 2, wherein the fixed core (24) is sealed in the central seat (200) identified by the coil 20 by means of a second sealing ring (312).

4. A solenoid valve (900) according to any of claims 1 or 2, wherein the pilot assembly (2) comprises a hollow tubular member (268) coaxially disposed in the central seat (200) so as to accommodate at least the movable core (22), wherein the tubular member (268) has a tubular member base (2680) extending between the pole piece (266) and the valve body (1).

5. Solenoid valve (900) according to claim 4 when dependent on claim 2, wherein the tubular element base (2680) forms together with the cylindrical lateral surface (12) and the polar expansion end (2660) the annular seat (300) in which a first sealing ring (310) is housed.

6. A solenoid valve (900) according to any of claims 2-5, wherein the pole expansion end (2660) has a substantially truncated-conical shape, and wherein the first sealing ring (310) engages the truncated-conical side surface of the pole expansion end (2660).

7. Solenoid valve (900) according to any of the preceding claims, wherein the movable core (22) houses an elastic element (220) which engages the fixed core (22) so as to elastically maintain the movable core (22) in the closed position.

8. Solenoid valve (900) according to claim 7, wherein said elastic element (220) is a cylindrical spring.

9. Solenoid valve (900) according to any of claims 4-8, wherein the fixed core (24) is sealed in the tubular element (268) by means of a second sealing ring (312).

10. Armature (26) for solenoid valve (900), comprising an armature body made of ferromagnetic material and comprising: - a head portion (260) extending into a first armature plane (500); - a base portion (264) extending into a second armature plane (600) parallel to the first armature plane (500); - at least one lateral portion (262) which extends between the head portion (260) and the base portion (264) in a third armature plane (700) substantially orthogonal to the first armature plane (500) and to the second armature plane (600), characterised by the fact that in the base portion (264) an axial through opening (2640) is obtained and by the fact that the base portion (264), around the axial through opening (2640), presents a thickening of truncated-conical shape suitable for realising a polar expansion (266).

11. Armature (26) according to claim 10, wherein the armature body is obtained from a single piece.

12. Method of producing an armature (26) for a solenoid valve (900) according to claim 11, comprising the following steps: a) preparing a sheet metal (6) having a substantially rectangular shape; b) progressively deforming at least a portion of the sheet metal corresponding to the base portion (264) so ​​as to obtain the truncated-conical thickening suitable for realising the polar expansion (266); 5 c) further deforming the base portion (264) so ​​as to create the through axial opening (2640); d) bending the sheet metal (6) so as to define the head portion (260), the lateral portion (262) and the base portion (264).