Solenoid valve

Abstract

An electromagnetic valve (1) with: a valve actuating element (40) with an iron core section (43) which displaces in an axial direction (L) according to an excitation of an electromagnet, a valve body (10) with a plurality of ports (A, P, R) into or from which a pressure fluid flows, and a valve box (11) with which the ports (A, P, R) are connected, and a valve disc (3) which is received in the valve box (11) and which moves in the axial direction (L) towards and away from a valve seat (12) in the valve box (11) in accordance with the displacement of the valve actuating element (40) in order to change connection states between the ports (A, P, R), wherein the valve actuating element (40) comprises a valve retaining section (45) which holds the valve disc (3), wherein the valve disc (3) can move relative to the valve actuating element (40) in the axial direction (L), wherein the valve retaining section (45) has a free end and a base end on both sides in the axial direction (L) and wherein the base end of the valve retaining section (45) is connected to an end of the iron core section (43) in the axial direction (L), wherein an elastic element (26) is provided inside the valve box (11) and wherein the elastic element (26) constantly presses the valve disc (3) in the axial direction (L) towards the valve seat (12) in order to cause the valve disc (3) to sit on the valve seat (12) by means of a preload force, wherein the valve retaining section (45) has a pair of retaining arms (45) extending seamlessly and integrally from one end (43a) of the iron core section (43) in the axial direction (L), or has a pair of retaining arms (45) formed by separate elements and integrally connected to the iron core section (43), and wherein the valve disk (3) is held between the retaining arms (45) such that it can slide in the axial direction (L), wherein a cap element (70) extends between the free end sections of the pair of retaining arms (45), wherein the cap element (70) has a valve engagement section (73) and the valve engagement section (73) engages with an attack section (4) of the valve disc (3) which rests on the valve seat (12) when the valve actuating element (40) displaces in a direction opposite to the direction in which the elastic element (26) pushes the valve disc (3), and the valve disc (3) lifts off the valve seat (12) against the preload force of the elastic element (26), and wherein the valve engagement section (73) is not in contact with the valve disc (3) when the valve disc (3) rests on the valve seat (12) in accordance with a displacement of the valve actuating element (40) in the direction in which the elastic element (26) pushes the valve disc (3).

Description

Technical field

[0001] The present invention relates to an electromagnetic valve (solenoid valve) which displaces a valve disc in a direction in which a movable core is displaced by excitation of an electromagnet in order to change connection states between several terminals. State of the art

[0002] An electromagnetic valve which displaces a valve disc in a direction in which a movable core is displaced by excitation of an electromagnet in order to change connection states between several terminals is already generally known, as described in patent document (PTL) 1.

[0003] The solenoid valve described in PTL 1 has a valve retaining section (valve disc) that is axially fixed to one end of the movable core. The valve retaining section includes a valve disc (elastic section) made of a resin or plastic material. A valve chamber, which accommodates the valve retaining section and the valve disc, is formed within a valve body. Several ports are connected to the valve chamber. An opening is formed in a bottom surface of the valve chamber, which is connected to one of the ports. A valve seat is provided around the circumference of the opening, towards and away from which the valve disc moves.

[0004] As described above, in the known solenoid valve, the valve disc is located on the valve retaining section, which is attached to the movable core. The valve disc moves towards and away from the valve seat. The movable core and the valve disc are actuated together. When the valve disc strikes the valve seat to engage it, the kinetic energy of the movable core thus causes a higher external force, such as a compression force, to be exerted directly on the valve disc in the axial direction. If such a high external force is repeatedly exerted on the valve disc, it can wear out or become irreversibly deformed (permanently deformed), so that its dimensions change in the axial direction over time.Therefore, the stroke of the movable core, i.e., the distance from the valve seat to the valve disc, can change, and the flow rate of a fluid flowing through the valve seat or the response behavior of the solenoid valve can change.

[0005] Another solenoid valve is known from US 2007 / 0 145 318 A1. Cited documents Patent literature

[0006] PTL 1 JP 2003 - 172 472 A Summary of the invention: Technical problem

[0007] It is a technical object of the present invention to propose an electromagnetic valve which actuates a valve disc by displacing a movable core due to the excitation of an electromagnet, wherein the electromagnetic valve reduces an external force, for example a compression force, exerted on the valve disc which is to sit on a valve seat in order to prevent wear or irreversible deformation of the valve disc by the external force repeatedly exerted on the valve disc, and in order to prevent, as far as possible, any change in the flow rate of the fluid flowing through the valve seat or in the response behavior of the electromagnetic valve. Solution to the task

[0008] This problem is solved by the solenoid valve with the features of claim 1. Preferred embodiments are evident from the dependent claims.

[0009] This prevents the kinetic energy of the valve actuating element, including the moving core, from being directly transferred to the valve disc when the valve disc strikes the valve seat, thus reducing the external force applied to the valve disc in the axial direction. This prevents wear or irreversible deformation (permanent deformation) of the valve disc caused by repeated external forces, thereby preventing changes in the valve disc's axial size over time. Consequently, it prevents changes in the stroke of the moving core, i.e., the distance between the valve seat and the valve disc.This prevents, as far as possible, any changes to the flow rate of the fluid flowing through the valve seat or to the response behavior of the solenoid valve.

[0010] In the solenoid valve described above, the valve holding section preferably has a positioning surface that is a flat surface perpendicular to an axis and facing in the direction in which the elastic element pushes the valve disc. A contact surface is provided in the valve housing of the valve body, wherein the contact surface is a flat surface parallel to the positioning surface, towards and away from which the positioning surface moves according to a displacement of the iron core section.

[0011] When the valve disc rests on the valve seat because the valve actuating element moves in the direction in which the elastic element pushes the valve disc, the positioning surface rests against the contact surface and a gap, which is smaller than the stroke of the valve actuating element, is formed between the valve engagement section and the engagement section of the valve disc.

[0012] This ensures that the movable core is accurately positioned relative to the valve body when the valve disc strikes the valve seat to engage. This allows for more precise control of the solenoid valve's response.

[0013] In this case, the valve seat can be provided on a bottom wall surface of the valve box that faces a free end of the valve actuating element, a free end surface of the valve holding section can form the positioning surface, and the contact surface can be provided on the bottom wall surface of the valve box.

[0014] Furthermore, the valve engagement section of the cap element is preferably arranged in the axial direction between the free end surface of the valve holding section and the attack section of the valve disc.

[0015] Applying any of the above-mentioned design features will enable a more sensible design of a solenoid valve.

[0016] In the solenoid valve according to the present invention, the valve body preferably comprises a first valve seat, which serves as the valve seat, and a second valve seat, which is positioned such that it faces the first valve seat in the axial direction. The valve disc is located in a space between the valve seats and is constantly pressed towards the first valve seat by the elastic element. The valve engagement section, which is provided on the valve holding section, is formed from a thin plate that is elastic in the axial direction.The valve engagement section engages the attack section of the valve disc that sits on the first valve seat when the valve actuating element moves in a direction opposite to the direction in which the elastic element pushes the valve disc, separating the valve disc from the first valve seat against a preload force of the elastic element and causing the valve disc to sit on the second valve seat.

[0017] Thus, the valve engagement section provided on the valve retaining section is formed by a thin plate that is elastic in the axial direction. When the valve disc abuts the second valve seat to seat, the external force exerted on the valve disc in the axial direction can be absorbed and thus reduced by the valve engagement section. This design can therefore prevent, as far as possible, wear or irreversible deformation (permanent deformation) of the valve disc when such an external force is repeatedly applied to it.

[0018] In this case, the first valve seat can preferably be provided on the bottom wall surface of the valve box that faces the free end of the valve holding section.

[0019] Applying such a design allows for a more sensible design of a solenoid valve. Advantageous effects of the invention

[0020] As described above, in the solenoid valve according to the present invention, the valve engagement section of the valve actuation section is not in axial contact with the valve disc when the valve disc abuts the valve seat to seat. This design prevents the kinetic energy of the valve actuation element, including the moving core, from being directly transferred to the valve disc and thus reduces the external force exerted on the valve disc in the axial direction. Therefore, wear or irreversible deformation (permanent deformation) of the valve disc caused by repeated application of such an external force can be prevented, thus avoiding changes in the dimensions of the valve disc in the axial direction over time.Accordingly, changes in the stroke of the movable core, i.e., the distance from the valve seat to the valve disc, can be prevented. This minimizes any changes in the flow rate of the fluid flowing through the valve seat or in the response behavior of the solenoid valve. Brief description of the drawings Fig. Figure 1 is a lateral section through a solenoid valve according to an embodiment of the present invention in a demagnetized state. Fig. Figure 2 is a vertical section through the solenoid valve according to Fig. 1. Fig. 3 is an enlarged schematic section through a main section, showing a state around a valve box in Fig. 1 shows. Fig. Figure 4 is a side section through the solenoid valve in an energized state. Fig. Figure 5 is a vertical section through the solenoid valve according to Fig. 4. Fig. 6 is an enlarged schematic section through a main section, showing a state around a valve box in Fig. 4 shows. Fig. Figure 7 is a schematic perspective exploded view of components relating to a magnetic section according to the present embodiment. Fig. Figure 8 is an enlarged section through a segment along line VIII-VIII in Fig. 4. Fig. Figure 9 is a schematic perspective view of a valve actuating element before a cap element is attached to the retaining arms of the valve actuating element. Fig. Figure 10 is a schematic perspective view of the state, which corresponds to the state in Fig. Figure 9 follows, in which guide grooves of a valve disc are placed on the retaining arms. Fig. Figure 11 is a schematic perspective view of the state which corresponds to the state in Fig. 10 follows, with the cap element extending between the retaining arms. Fig. Figure 12 is a schematic view of the state in which the valve actuating element is received in a central hole of a coil body. Fig. Figure 13 is a schematic top view of an opening of the coil body, which is located closer to the valve body. Fig. 14 is an enlarged section through a main section along line XIV-XIV in Fig. 1. Fig. Figure 15 is a schematic perspective view of the state in which a magnetic ring is attached to an engagement projection of the coil body. Description of embodiments

[0021] Fig. 1 to Fig. Figure 15 shows an electromagnetic valve according to an embodiment of the present invention. An electromagnetic valve (solenoid valve) 1 according to the present invention essentially comprises a main valve section 2 with a valve disc 3 for switching a flow passage through which a pressurized fluid, for example air, flows, and a solenoid section 7 which actuates the valve disc 3 of the main valve section 2. The main valve section 2 and the solenoid section 7 are connected in series along one direction of an axis L of the electromagnetic valve 1.

[0022] As from the Fig. 1 and Fig. As can be clearly seen in Figure 2, the main valve section 2 comprises a valve body 10 with a rectangular cross-section. A supply port P, an outlet port A, and an exhaust port R are formed in a first side face of the valve body 10. A valve box 11, with which the supply port P, the outlet port A, and the exhaust port R communicate, is formed in the valve body 10. A seal 29 is attached to these ports.

[0023] As in Fig. 1 and Fig. As shown in Figure 4, a first valve seat 12 and a second valve seat 13, towards and away from which the valve disc 3 moves, are provided in the valve housing 11. The first valve seat 12 and the second valve seat 13 are arranged so that they face each other in the direction of the axis L. The first valve seat 12 is located on a bottom wall surface 14 of the valve housing 11 such that it surrounds a supply passage opening 15 on a substantially central section of the bottom wall surface and projects towards the magnet section 7. The supply passage opening 15 communicates with a supply connection passage 16, which is located closer to a base of the valve body 10 than the bottom wall surface 14. The supply connection passage 16 is connected to the supply passage P. Thus, the supply passage P communicates with the valve housing 11 through the supply passage opening 15.

[0024] On the other hand, the second valve seat 13 is provided on a holder 17, which is attached to the valve box 11. The holder 17 is made of a resin or plastic material and is received in the valve box 11 in a section that is closer to an opening edge of the valve box 11 (closer to the solenoid section 7) than the valve disc 3. The holder 17 comprises an annular outer circumferential section 20 that fits onto the inner circumferential section of the valve box 11, and a projection 19 that is provided within the annular outer circumferential section 20 such that it projects towards the first valve seat 12.

[0025] As in Fig. 1 and Fig. As shown in Figure 2, an exhaust passage 21, which communicates with the exhaust port R, is formed on a front (end) section of the projection 19 of the holder 17. The second valve seat 13, which has an annular shape, is provided around the exhaust passage 21. An annular groove 22 is formed in the annular outer circumferential section 20. Sealing elements 23 are attached to both sides of the annular groove 22 in the direction of the axis L to hermetically seal the interior of the valve housing 11. The annular groove 22 communicates with an exhaust connection passage 24, which communicates with the exhaust passage 21. Thus, the exhaust port R communicates with the interior of the valve housing 11 via the annular groove 22, the exhaust connection passage 24, and the exhaust passage 21.Between the projection 19 and the annular outer circumferential section 20, a pair of insertion holes 25 are formed, through which a pair of retaining arms 45 of a valve actuating element 40, which will be described later, are inserted (see . Fig. 1 and Fig. 9).

[0026] As in Fig. 1 and Fig. As shown in Figure 4, the valve disc 3, which is a poppet or disc valve, is located in the valve body 11 in the space between the first valve seat 12 and the second valve seat 13. The valve disc 3 is made of a resin or plastic material with some elasticity and sealing properties, such as rubber, and has a substantially rectangular shape. The valve disc 3 moves towards and away from the first valve seat 12 and the second valve seat 13 to change the connection states between the ports P, A, and R. An elastic element 26, formed by a coil spring, is arranged between the valve disc 3 and the holder 17, which is fixed to the valve body 2. The elastic element 26 constantly presses the valve disc 3 towards the first valve seat 12.When the magnetic section 7 is in a non-excited state (demagnetized state), the valve disc 3 is placed on the first valve seat 12 by the preload force of the elastic element 26 (cf. . Fig. 1 to Fig. 3) In the present embodiment, the base end of the projection 19 of the holder 17 serves as a spring seat for the elastic element 26.

[0027] As in Fig. As shown in Figure 8, the valve disc 3 has a lateral shape in its end faces in the width direction of the valve disc 3 (left-right direction). Fig. 8) A pair of guide grooves 3a opens in opposite directions and extends in the direction of the axis L. When a pair of retaining arms 45 of the valve actuating element 40, described below, is inserted into the guide grooves 3a, the valve disc 3 is held between the pair of retaining arms 45 so that it can slide in the direction of the axis L. This design with the guide grooves 3a prevents the valve disc 3 from moving in the direction perpendicular to the axis of the valve actuating element 40 and prevents displacement of the axis of the valve disc 3. Thus, the valve disc 3 can be securely seated on the first valve seat 12 and the second valve seat 13.

[0028] The following section describes magnetic section 7. As in Fig. 1 and Fig. As shown in Figure 7, the magnetic section 7 has a magnetic cover 30 with a rectangular cross-section and a first end (upper end in Fig. 1) in the direction of the axis L, which is closed with a cap 31. As in Fig. As shown in Figure 1, the magnetic cover 30 comprises a coil former 60 around which an excitation coil 32 is wound, a stationary core 35 attached to a central hole 60a of the coil former 60, the valve actuating element 40 inserted into the central hole 60a so that it can slide in the direction of the axis L, and a magnetic ring 80 positioned at one end of the coil former 60 near the valve body 2 so that it surrounds the opening of the central hole 60a. Fig. 1 and Fig. As shown in Figure 4, annular grooves 60b are formed between the cap 31 and the coil former 60, and between the coil former 60 and the magnetic ring 80. Sealing elements 38 are installed in the respective annular grooves 60b. A pair of coil terminals 39, which are electrically connected to the excitation coil 32, project from the side surface of the magnetic cover 30. Conducting wires are connected to the coil terminals 39.

[0029] The stationary core 35 is made of a metal material and has the shape of an essentially rectangular plate. The stationary core 35 comprises flanged sections 35a at a first end (upper end in Fig. 1) in the direction of the axis L. The stationary core 35 is held between the coil former 60 and the cap 31, with the flange sections 35a engaging an end section of the coil former 60 that is closer to the cap 31.

[0030] The valve actuating element 40 comprises a movable core section 43, which displaces in the direction of the axis L in accordance with an excitation of the magnetic section 7. The movable core section 43 is positioned so that it faces the stationary core 35 and is attracted to or separated from the stationary core 35 when the excitation coil 35 is switched on or off, respectively. The valve actuating element 40 displaces together with the movable core section 43 in accordance with the displacement of the movable core section 43 in the direction of the axis L, in order to cause the valve disc 3 to selectively seat on either the first valve seat 12 or the second valve seat 13. When the excitation coil 32 is in the switched-on state (excited state), as described in Fig. 4 to Fig. As shown in Figure 6, in particular the valve actuating element 40 is pulled towards the stationary core 35 and the valve disc 3 releases the first valve seat 12 to place on the second valve seat 13, so that the supply port P and the outlet port A are connected to each other through the valve box 11.

[0031] If, on the other hand, the excitation coil 32 is not switched on (demagnetized state), as is the case in Fig. 1 to Fig. As shown in Figure 3, the valve actuation section 40 is spaced away from the stationary core 35 so that the valve disc releases the second valve seat 13 to fit onto the first valve seat 12, and the outlet port A and the exhaust port R are connected to each other through the valve box 11.

[0032] As in Fig. 1 and Fig. As shown in Figure 4, the valve actuating element 40 also includes a valve retaining section which holds the valve disc 3, allowing the valve disc 3 to move in the direction of the axis L relative to the valve actuating element 40. The valve retaining section comprises a pair of retaining arms 45 that extend seamlessly and integrally from one end 43a of the movable core section 43 in the direction of the axis L. The valve retaining section has a free (distal) end and a base end at both its sides in the direction of the axis L. The base end of the valve retaining section, that is, the base ends of the retaining arms 45, is connected to one end 43a of the movable core section 43 in the direction of the axis L. These retaining arms 45 are located side by side at the ends of the valve actuating element 40 in the lateral direction (left-right direction). Fig. 1) arranged so that they are symmetrical on both sides about the axis L.

[0033] The valve actuating element 40 is formed from a single magnetic metal plate. By stamping out this metal plate, the movable core section 43 and the valve retaining section (i.e., the retaining arms 45) are formed in one piece. As in Fig. 2 or Fig. 9, Fig. 10 to Fig. As shown in Figure 11, there are thus two surfaces 50 that are parallel to each other on both sides in the thickness direction of the valve actuation section 40 (left-right direction). Fig. 2) extend, individual flat surfaces that extend constantly from the movable core section 43 to the support arms 45.

[0034] As in Fig. 1 and Fig. As shown in Figure 4, the pair of retaining arms 45 extends through the pair of insertion holes 25, which open in the holder 17, into the valve box 11 of the valve body 2. Inside the valve box 11, they are inserted into the pair of guide grooves 3a (see Figure 4). Fig. 8), which are formed in the valve disc 3, so that they can be displaced in the direction of the axis L relative to the valve disc 3. Thus, the valve disc 3 is held between the pair of retaining arms 45 in such a way that it can slide in the direction of the axis L.

[0035] Instead of fixing the valve disc 3 to the valve actuating element 40, it is held movably by the valve actuating element 40, so that the valve holding section of the valve actuating section 40 can be designed more freely and a simpler construction or a simpler shape can be achieved.

[0036] As in Fig. 3 and Fig. As shown in Figure 6, the pair of retaining arms 45 each has engagement hooks 47 at their free end sections, projecting away from each other. Each of the engagement hooks 47 has an inclined surface 47a at its free end section. The inclined surface 47a is gradually inclined towards the axis L as it approaches the free end surface 46 of the associated retaining arm 45. Each of the engagement hooks 47 has an engagement surface 47b at its base end section, which is formed at one end surface perpendicular to the axis L.

[0037] As in Fig. 3, Fig. 6 and Fig. As shown in Figure 9, a cap element 70 extends between the free end sections of the pair of retaining arms 45. The cap element 70 is formed by an elastic thin metal plate with a substantially U-shaped cross-section. The cap element 70 has a pair of engagement openings 71 that engage with the engagement hooks 47, and a valve opening 72 located between the pair of engagement openings 71. The valve disc 3 rests on the first valve seat 12 through the valve opening 72.

[0038] As in Fig. As shown in Figure 9, the cap element 70 has a thin, plate-shaped valve engagement section 73 extending in a direction perpendicular to the axis L and elastic in the direction of the axis L, and a pair of locking sections 74 extending from the left and right ends of the valve engagement section 73 in a direction substantially perpendicular to the valve engagement section 73. Connecting sections between the valve engagement section 73 and the locking sections 74 are gently arcuate. When the valve actuating element 40 is drawn towards the stationary core 35, the valve engagement section 73 engages with the engagement section 4 of the valve disc 3, which rests on the first valve seat 12, that is, a valve seat end face facing the first valve seat 12, as shown in Figure 9. Fig. Figure 6 is shown. Thus, the valve disc 3 is lifted from the first valve seat 12 against the preload force of the elastic element 26 and placed onto the second valve seat 13. The valve engagement section 73 has a valve opening 72 with a substantially circular opening edge. As shown in Fig. As shown in Figure 3, the valve disc 3 can be placed on the first valve seat 12 through the valve opening 72.

[0039] The engagement openings 71 are rectangular and form sections transversely across the valve engagement section 73 and the locking sections 74. Outwardly curved sections 75 are formed at the free ends of the locking sections 74. As described above, the cap element 70, formed from a thin metal plate with a simple structure, enables, in this embodiment, the valve disc to be attached to the valve retaining section of the valve actuating element 40 and to form the valve engagement section 73.

[0040] The cap element 70 is attached between the retaining arms 45 in the following manner. First, as shown in Fig. As shown in Figure 9, the valve actuating element 40, the holder 17, the elastic element 26, the valve disc 3, and the cap element 70 are prepared. The elastic element 26, formed by the coil spring, is attached to the outer circumference of the projection 19 of the holder 17. The axes of the valve actuating element 40 and the holder 17, to which the elastic element 26 is attached, are then aligned with each other, and the pair of retaining arms 45 is inserted from one side of the holder 17 in the direction of axis L (the side opposite the projection 19) into the insertion holes 25 of the holder 17. Simultaneously, the valve disc 3 is pressed against the preload force of the elastic element 26 from the side opposite the valve actuating element 40 (retaining arms 45) (from the side of the projection 19) toward the holder 17.Thus, the guide grooves 3a of the valve disc 3 are placed on the pair of retaining arms 45, which extend from the insertion holes 25 (cf. . Fig. 10). In this state, the cap element 70 is attached between the retaining arms 45.

[0041] When the cap element 70 is pressed relative to the retaining arms 45, with the opening side (side of the locking sections 74) of the cap element 70 facing the free end surfaces 46 of the retaining arms 45, the curved sections 75 of the pair of locking sections 74 of the cap element 70 ride on the inclined surfaces 47a of the engagement hooks 47 on the free end sections of the retaining arms 45. This is in Fig. Figure 10 shows that the distance between the pair of locking sections 74 is elastically increased. Then, the opening edges (free ends) of the engagement openings 71 of the locking sections 74 are shifted to the positions of the engagement surfaces 47b of the engagement hooks 47, and the positions of the engagement openings 71 and the positions of the engagement hooks 47 are aligned with each other. Thus, the enlarged locking sections 74 elastically return to their original position, and the engagement hooks 47 are inserted into the engagement openings 71, as shown in Figure 10. Fig. Figure 11 shows the attachment of the cap element 70 to the retaining arms 45. At this time, the position of the valve engagement section 73 of the cap element 70 is located in the direction of the axis L between the positions of the free end faces 46 of the retaining arms 45 and the position of the attack section 4 of the valve disc 3.

[0042] As in Fig. 3, Fig. 4 or Fig. As shown in Figure 6, the free end surfaces 46 of the pair of retaining arms 45 are flat surfaces perpendicular to the axis L. The free end surfaces 46 form positioning surfaces that point in the direction in which the elastic element 26 pushes the valve disc 3, i.e., towards the first valve seat 12. On the other hand, two contact surfaces 27 are provided on the bottom wall surface 14 of the valve housing 11. The free end surfaces 46 move towards and away from these contact surfaces 27 when the movable core section 43 is displaced. The two contact surfaces 27 are flat surfaces parallel to the free end surfaces 46 of the retaining arms 45. The contact surfaces 27 are arranged on both sides of the first valve seat 12, i.e., on both sides of the valve body 10 in the lateral direction (left-right direction). Fig. 3), and protrude from the magnetic section 7. The height of the contact surfaces 27, by which the contact surfaces 27 project from the bottom wall surface 14 into the valve box 11, is less than the height by which the first valve seat 12 projects from the bottom wall surface 14 into the valve box 11. In particular, the contact surfaces 27 are arranged closer to the bottom wall surface 14 than the first valve seat 12.

[0043] As in Fig. 1 and Fig. As shown in Figure 3, the free end surfaces 46 of the pair of retaining arms 45 rest against the contact surfaces 27 when the valve actuating element 40 is moved in a direction in which the elastic element 26 is compressed, so that the valve disc 3 rests on the first valve seat 12. As shown in Fig. As shown in Figure 3, at this time the valve engagement section 73 of the cap element 70 is not in contact with the attack section 4 of the valve disc 3 and a gap G, which is smaller than a stroke of the valve actuation section 40, is formed between the valve engagement section 73 and the attack section 4.

[0044] As in Fig. As shown in Figure 12, the central hole 60a of the coil body 60, which receives the valve actuating element 40, has a substantially rectangular cross-section with a pair of first inner surfaces 61 and a pair of second inner surfaces 65. The first inner surfaces 61 face a pair of surfaces 50 on both sides of the valve actuating section 40 in the thickness direction, and the second inner surfaces 65 face a pair of end surfaces 51 parallel to each other and at both ends of the valve actuating element 40 (movable core section 43) in the width direction (left-right direction). Fig. 12) facing.

[0045] On both side sections 62 of the pair of first inner surfaces 61 in the width direction, stepped sections 64 are formed to reduce the distance between the first inner surfaces 61 to such an extent that it is smaller than the distance between middle sections 63, which are held between the two side sections 62. The stepped sections 64 extend in the direction of the axis L and are connected from both side sections 62 of the first inner surface 61 to the second inner surfaces 65 in the circumferential direction of the central hole 60a. A pair of convex (curved) threads 66 are formed on the pair of second inner surfaces 65 such that they extend in the direction of the axis L. The convex threads 66 are formed on the second inner surfaces 65 such that they face each other (facing inwards) and have an arcuate cross-section.

[0046] When the movable core section 43 of the valve actuating element 40 is inserted into the central hole 60a of the coil body 60, the pair of side end surfaces 51 are held by the pair of convex threads 66 so that they can slide in the direction of the axis L, and the pair of surfaces 50 are held by the stepped sections 64 so that they can slide in the direction of the axis L. The valve actuating element 40 extends through the magnetic ring 80 so that its free end projects towards the valve body 2.

[0047] In the present embodiment, both end faces 51 of the valve actuating element 40 and both side sections of the pair of surfaces 50 are held by the convex threads 66 and the stepped sections 64 so that they can slide in the central hole 60a of the coil body 60. This effectively prevents displacement of the axis of the valve actuating element 40.

[0048] As in Fig. 7 and the Fig. 13, Fig. 14 to Fig. As shown in Figure 15, a pair of projecting engagement walls 67 are provided in the opening of the central hole 60a, facing the valve body 2. The projecting engagement walls 67 extend from the pair of second inner surfaces 65 in the direction of the axis L. The magnetic ring 80, which is designed to surround the central hole 60a, has an engagement hole section 81. When the projecting engagement walls 67 are inserted into the engagement hole sections 81, the magnetic ring 80 is positioned so that it is coaxial with the coil body 60.

[0049] As in Fig. 7 and the Fig. 13, Fig. 14 to Fig. As shown in Figure 15, the protruding engagement walls 67 of the coil body 60 each comprise a side wall section 68 facing both side sections 51 of the valve actuating element 40, and semicircular arc-shaped wall sections 69 on both sides (upper and lower sides in Fig. 13) of side wall section 68. As in Fig. 7, Fig. 14 and Fig. As shown in Figure 15, the engagement hole section 81 of the magnetic ring 80 has, on the other hand, a pair of first surface sections 82, which extend parallel to each other such that they face the pair of surfaces 50 of the valve actuating section 40, and second surface sections 83 on both sides of the first surface sections 82. The distance between the first surface sections 82 is greater than the thickness of the valve actuating element 40 (distance between the pair of surfaces 50) and the distance between the middle sections 63 of the first inner surfaces 61 of the central hole 60a.

[0050] Every second surface section 83 comprises a straight section 84, with which the engagement projection 67 engages and which extends in the direction perpendicular to the first surface section 82, and semicircular arc-shaped sections 85 on both sides of the straight section 84. The straight section 84 engages with the outer circumferential surface of the side wall section 68 of the corresponding projecting engagement wall 67. The arc-shaped sections 85 engage with the outer circumferential surfaces of arc-shaped end sections 69 of the projecting engagement wall 67.

[0051] As in Fig. As shown in Figure 14, the magnetic ring 80 has an outer circumferential surface, which is essentially rectangular in a plan view, and a pair of recesses 86 in both side faces of the outer circumferential surfaces in the width direction. The pair of recesses 86 engages with a pair of inwardly directed projections 28 provided in the valve box 11 of the valve body 2.

[0052] When the magnetic ring 80 is attached to the opening of the central hole 60a, as shown in Fig. As shown in Figure 14, the engagement projections 67 of the coil body 60 and the engagement hole section 81 of the magnetic ring 80 engage with each other in the manner described above, and the recesses 86 and the inwardly directed projections 28 engage with each other. Thus, the axes of the magnetic ring 80 and the central hole 60a of the coil body 60 are aligned with each other. When the magnetic ring 80 is attached to the opening of the coil body 60, the engagement projections 67 are positioned between the two side sections 51 of the valve actuation section 40 and the second surface sections 83 of the magnetic ring 80. In this state, a gap is formed between each of the first surface sections 82 of the magnetic ring 80 and the associated surface 50 of the valve actuation element 40. This design prevents the valve actuation element 40 and the magnetic ring 80 from coming into direct contact with each other.This reliably prevents the efficiency of magnetic section 7 from being reduced.

[0053] In the solenoid valve 1 with the above-described construction, the valve actuating element 40 is spaced away from the stationary core 35 when the excitation coil 32 is not switched on (demagnetized state), as shown in the Fig. 1 and Fig. Figure 2 illustrates this. When the excitation coil 32 is in the demagnetized state, the valve disc 3 rests on the first valve seat 12, with the preload force of the elastic element 26 exerted on it by the holder 17 to block a connection between the supply port P and the valve box 11. At this time, the second valve seat 13, which is arranged so that it faces the first valve seat 12 in the direction of the axis L, is open, and the outlet port A communicates with the outlet port R through the outlet passage 21 and the outlet connection passage 24 in the valve box 11. Thus, the pressurized fluid in the valve box 11 is discharged to the environment through the outlet port R, which is connected to the environment.

[0054] In the present embodiment, when the excitation coil 32 is in the demagnetized state as described in Fig. As shown in Figure 3, the free end faces 46 of the valve retaining section of the valve actuating element 40, i.e., the pair of retaining arms 45, are in contact with the pair of contact surfaces 27 of the bottom wall section 14 of the valve housing 11. The valve disc 3 sits between the pair of retaining arms 45 on the first valve seat 12 in the valve opening 72 of the cap element 70. At this time, the valve seat end face (attack section 4) of the valve disc 3, which faces the first valve seat 12, and the valve engagement section 73 of the cap element 70 are not in contact with each other, and a gap G, which is smaller than the stroke of the valve actuating element 40, is formed between the attack section 4 and the valve engagement section 73.

[0055] When the excitation coil 32 is switched on in this state, so that it transitions into the energized state, the valve actuating element 40 is attracted to the stationary core 35 and displaced in the direction of the axis L towards the stationary core 35 against the preload force of the elastic element 26, which pushes the valve disc 3 towards the first valve seat 12, as shown in Fig. 4 to Fig. 6 is shown. As in Fig. Figure 6 shows that when the valve actuating element 40 is displaced in the direction of the axis L, the two retaining arms 45 of the valve actuating element 40 are spaced apart from the contact surface 27, and the valve engagement section 73 of the cap element 70, which is mounted between the retaining arms 45, engages with the contact surface 4 of the valve disc 3. The valve disc 3, which rests on the first valve seat 12, is displaced to the second valve seat 13, with the guide grooves 3a being held by the retaining arms 45.

[0056] As described above, a gap G is formed between the attack section 4 of the valve disc 3 and the valve engagement section 73 of the cap element 70. Therefore, when the excitation coil 32 is switched to the energized state, the gap G between the attack section 4 and the valve engagement section 73 is initially reduced, instead of the valve disc 3 moving simultaneously with the movement of the valve actuating element 40 to the second valve seat 13. After the gap G has been reduced to zero, the valve engagement section 73 engages with the attack section 4 of the valve disc 3, and then the valve disc 3 moves to the second valve seat 13.

[0057] When the valve actuation section 40 is tightened, the valve disc 3 is placed on the second valve seat 13 to close the outlet passage 21 and to release the first valve seat 12, which faces the second valve seat 13. Accordingly, the supply port P communicates with the outlet port A through the supply passage 15 and the valve body 11, and the pressurized fluid supplied by the supply port P is discharged through the outlet port A (see figure). Fig. 4 to Fig. 6) Here, the valve engagement section 73 of the cap element 70, which is provided on the pair of retaining arms 45, is formed by a thin plate that is elastic in the direction of the axis L. When the valve disc 3 contacts the second valve seat 13, the force exerted on the valve disc 3 in the direction of the axis L can be absorbed by the valve engagement section 73. This design can prevent the valve disc 3 from wearing down or becoming irreversibly deformed (permanently deformed) when such a force is repeatedly exerted on the valve disc 3.

[0058] When the excitation coil 32 is no longer switched on and switches to the demagnetized state, which is in the Fig. 1, Fig. 2 to Fig.As shown in Figure 3, the valve actuating element 40 is spaced apart from the stationary core 35, and the valve disc 3 is lifted from the second valve seat 13 due to the preload force of the elastic element 26. As described above, the valve disc 3 closes the first valve seat 12 and exposes the second valve seat 13, so that the outlet port A connects to the exhaust port R through the valve body 11 and is exposed to the environment. The flat free end surfaces 46 of the pair of retaining arms 45 rest against the pair of arm contact surfaces 27, which run parallel to the free end surfaces 46, thus precisely positioning the valve actuating element 40 relative to the valve body 2. This allows for more precise control of the solenoid valve's response.

[0059] When the free end surfaces 46 of the retaining arms 45 rest against the arm contact surfaces 27, the valve disc 3 rests on the first valve seat 12, forming the gap G between the attack section 4, which faces the first valve seat 12, and the valve engagement section 73 of the cap element 70.

[0060] The solenoid valve 1 according to the present embodiment, with the structure described above, can prevent the kinetic energy of the valve actuating element 40 from being applied directly to the valve disc 3 when the valve disc 3 contacts the first valve seat 12, and can thus reduce the external force applied to the valve disc 3 in the direction of the axis L. This prevents wear or irreversible deformation (permanent deformation) of the valve disc 3 caused by repeated application of such an external force, thus preventing the dimensions of the valve disc 3 from changing over time in the direction of the axis L. Accordingly, a change in the stroke of the valve actuating element 40, i.e., the distance from the first valve seat 12 to the valve disc 3, can be prevented.This helps to avoid, as far as possible, any changes to the flow rate of the fluid flowing through the valve seat 12 or to the response behavior of the solenoid valve.

[0061] The solenoid valve according to the present invention has been described so far. However, the invention of the present application is not limited to the above embodiment and can, of course, be modified in its design in various ways without departing from the scope of the patent claims.

[0062] For example, in the present embodiment, the valve actuating element 40 or the movable core section 43 and the valve retaining section (retaining arms 45) are formed by punching out a single metal plate. However, as long as the movable core section 43 is magnetic and able to be attracted to and spaced apart from the stationary core 35, the valve retaining section 40 can also be formed by separate elements that are connected to each other.

[0063] Although the above example describes a three-way solenoid valve, the number of connections is not limited to this and can also be two. Reference symbol list 1 solenoid valve 3 Valve disc 4 Attack Section 7 Magnetic section 10 valve bodies 11 Valve box 12 first valve seat 13 second valve seat 14 floor wall area 26 elastic element 27 Contact area 40 Valve actuating element 43 Iron core 43a End area 45 Retaining arm (valve retaining section) 46 free end area 73 Valve intervention section A Output port P Supply connection R outlet connection

Claims

[1] An electromagnetic valve (1) with: a valve actuating element (40) with an iron core section (43) which displaces in an axial direction (L) according to an excitation of an electromagnet, a valve body (10) with a plurality of ports (A, P, R) into or from which a pressure fluid flows, and a valve box (11) with which the ports (A, P, R) are connected, and a valve disc (3) which is received in the valve box (11) and which moves in the axial direction (L) towards and away from a valve seat (12) in the valve box (11) in accordance with the displacement of the valve actuating element (40) in order to change connection states between the ports (A, P, R), wherein the valve actuating element (40) comprises a valve retaining section (45) which holds the valve disc (3), wherein the valve disc (3) can move relative to the valve actuating element (40) in the axial direction (L), wherein the valve retaining section (45) has a free end and a base end on both sides in the axial direction (L) and wherein the base end of the valve retaining section (45) is connected to an end of the iron core section (43) in the axial direction (L), wherein an elastic element (26) is provided inside the valve box (11) and wherein the elastic element (26) constantly presses the valve disc (3) in the axial direction (L) towards the valve seat (12) in order to cause the valve disc (3) to sit on the valve seat (12) by means of a preload force, wherein the valve retaining section (45) has a pair of retaining arms (45) extending seamlessly and integrally from one end (43a) of the iron core section (43) in the axial direction (L), or has a pair of retaining arms (45) formed by separate elements and integrally connected to the iron core section (43), and wherein the valve disk (3) is held between the retaining arms (45) such that it can slide in the axial direction (L), wherein a cap element (70) extends between the free end sections of the pair of retaining arms (45), wherein the cap element (70) has a valve engagement section (73) and the valve engagement section (73) engages with an attack section (4) of the valve disc (3) which rests on the valve seat (12) when the valve actuating element (40) displaces in a direction opposite to the direction in which the elastic element (26) pushes the valve disc (3), and the valve disc (3) lifts off the valve seat (12) against the preload force of the elastic element (26), and wherein the valve engagement section (73) is not in contact with the valve disc (3) when the valve disc (3) rests on the valve seat (12) in accordance with a displacement of the valve actuating element (40) in the direction in which the elastic element (26) pushes the valve disc (3). [2] The solenoid valve (1) according to claim 1, wherein the valve retaining section (45) has a positioning surface which is a flat surface perpendicular to an axis (L) and points in a direction in which the elastic element (26) pushes the valve disc (3), wherein a contact surface (27) is provided in the valve box (11) of the valve body (10) and the contact surface (27) is a flat surface parallel to the positioning surface and wherein the positioning surface moves in accordance with a displacement of the iron core section (43) towards and away from the flat surface, and wherein the positioning surface rests on the contact surface (27) and a gap (G) which is smaller than a stroke of the valve actuating element (40) is formed between the valve engagement section (73) and the attack section (4) of the valve disc (3) when the valve disc (3) comes into contact with the valve seat (12) when the valve actuating element (40) is displaced in the direction in which the elastic element (26) pushes the valve disc (3). [3] The solenoid valve (1) according to claim 2, wherein the valve seat (12) is provided on a bottom wall surface (14) of the valve box (11) which faces a free end of the valve holding section (45), wherein a free end surface (46) of the valve holding section (45) forms the positioning surface and wherein the contact surface (27) is provided on the bottom wall surface (14) of the valve box (11). [4] The solenoid valve (1) according to claim 2, wherein a position of the valve engagement section (73) of the cap element (70) is arranged in the axial direction (L) between a position of the free end surface (46) of the valve retaining section (45) and a position of the attack section (4) of the valve disc (3). [5] The solenoid valve (1) according to claim 1, wherein a first valve seat (12), which serves as the valve seat (12), and a second valve seat (13), which is arranged such that it faces the first valve seat (12) in the axial direction (L), are arranged in the valve box (11), wherein the valve disc (3) is arranged in a space between the valve seats (12, 13) and is constantly pressed towards the first valve seat (12) by the elastic element (26) and wherein the valve engagement section (73) provided on the valve holding section (45) is formed by a thin plate which is elastic in the axial direction (L), and wherein the valve engagement section (73) engages with the attack section (4) of the valve disc (3) which sits on the first valve seat (12), corresponding to the displacement of the valve actuating element (40) in a direction opposite to the direction in which the elastic element (26) pushes the valve disc (3), lifts the valve disc (3) from the first valve seat (12) against the preload force of the elastic element (26) and causes the valve disc (3) to sit on the second valve seat (13). [6] The solenoid valve (1) according to claim 5, wherein the first valve seat (12) is arranged on the bottom wall surface (14) of the valve box (11) which faces the free end of the valve holding section (45).

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