JP2018096493A - Flow control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate unsatisfactory state in which a controlling operation becomes unstable when a driving operation is started (when a low voltage driving is performed) even under severe use environment such as a heat cycle and to assure high degree of safety and reliability in operation.SOLUTION: When a flow control valve 1 is constituted to comprise a valve body mechanism part 5 having a plunger part 7 for supporting a valve body part 6 with a valve part 6s formed by rubber raw material R and displaced in an axial direction Fs in correspondence with a value of a driving voltage applied to a solenoid part 3 and having an elastic member 8 for elastically supporting this plunger part 7 and an orifice part 9 arranged in front of an axial direction Fs of the valve part 6s to define a flow passage J and formed with metallic raw material M having a valve seat part 9s to be opened or closed, there is provided a DLC film forming layer 10 in which a surface 9sf of the valve seat part 9s to which at least the valve part 6s is abutted has a predetermined film thickness Ls improving a peeling characteristic when the valve part 6s abutted against said surface 9sf is spaced apart.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a flow rate control valve suitable for use in variably controlling the flow rate of various fluids such as gas flowing in a flow path.

  2. Description of the Related Art Conventionally, a plunger portion that supports a valve body having a valve member formed of a rubber material, is displaced in the axial direction in response to the magnitude of a drive voltage applied to the solenoid portion, and an elastic member that elastically supports the plunger portion. A valve body mechanism portion, and an orifice portion that is disposed in front of the valve body in the axial direction and that is provided so as to partition the flow path and that is formed of a metal material having a valve seat that is opened and closed by a valve member. As the valve, a flow control valve disclosed in Patent Document 1 and a flow control valve disclosed in Patent Document 2 are known.

  The flow control valve disclosed in Patent Document 1 uses a valve seat using a damping alloy having a gas injection hole (fluid outflow hole) and a valve seat, and uses a rubber-like elastic material for the valve seat of the valve seat. A valve body seated and separated via a seal member, and a valve seat is assembled to the first seat member on the support side, the first seat member, and a gas injection hole and a valve seat The maximum flow rate when the valve is opened is defined by the gap between the valve seat of the second seat member and the seal member, and the valve body is fully closed when the valve is closed. The position is defined by the contact of the valve body with the seat surface provided on the first seat member.

  Further, the flow control valve disclosed in Patent Document 2 has an outer yoke provided outside the solenoid and an inner yoke provided inside, and the rear end surface is opposed to the front end surface of the inner yoke and is applied to the solenoid. An electromagnetic drive unit having a plunger that displaces in accordance with the magnitude of the excitation voltage, a valve body having a valve member formed of rubber or the like that opens and closes the flow path by being provided at the front end of the plunger, and elastically supports the valve body A flow control valve comprising a valve mechanism having a diaphragm and a blocking block (valve seat) having a flat surface on which an inflow port with which the valve body can abut is formed, and the rear end surface of the plunger is ring-shaped flat And a convex portion (or a concave portion) having a tapered surface provided inside the flat portion, and the front end surface of the inner yoke is formed as a ring-shaped flat portion. It is formed by a combination with a concave portion (or convex portion) having a tapered surface provided inside the flat portion, and the ratio of the diameter of the convex portion or concave portion to the diameter of the rear end surface or the front end surface and the angle of the tapered surface are predetermined. The size is set.

JP 2010-19362 A JP 2010-25303 A

  However, the conventional flow control valves including the flow control valves disclosed in Patent Documents 1 and 2 described above have the following problems to be solved.

  In other words, the flow control valve has a so-called normal close function in which the valve member (valve element) abuts the valve seat and closes the flow path when the solenoid is not energized, and a rubber material is used for the valve member of the valve element. When a metal material is used for the valve seat, when driving a flow control valve that has been de-energized, the valve member may be in close contact with the valve seat depending on the operating environment, etc. This causes a problem that the control operation becomes unstable (impossible) during voltage driving.

  Specifically, as shown in FIG. 10, when driving is started after 24 hours of non-energization, the drive voltage Vd starts from around 7 [V] as shown by the characteristic line Eon in a normal temperature environment. As the voltage increases, the valve member (valve seat) opens corresponding to the magnitude of the voltage, and the flow rate [L / min] gradually increases correspondingly, but the heat cycle environment (temperature 80 After the temperature of [° C] and humidity of 90% is 8 hours and the temperature of 0 ° C and humidity of 0% is repeated for 8 hours twice, the valve member As shown by the characteristic line Eoc, the valve member is closed when the drive voltage Vd is kept close to 11 [V] and reaches a critical point near 11 [V], as shown by the characteristic line Eoc. An unstable operation is generated that leaves the seat and instantaneously shifts to full opening.

  This problem does not occur in normal use environments such as room temperature environments, and even if it occurs, it is often limited to the start of driving, etc., so there are aspects that are not regarded as problematic, but the stability of the flow control valve and This is not desirable from the viewpoint of ensuring reliability. Therefore, in general, the actual situation is to cope with the selection and surface treatment of the rubber material forming the valve member. In FIG. 10, Ern and Erc indicate characteristic lines when the surface of the valve member is subjected to a surface coating for reducing adhesion, and Ern is a room temperature environment and Erc is a heat cycle environment.

  However, even when such improvement processing is performed, the unstable operation in the heat cycle environment has not been completely eliminated, and it is further from the viewpoint of obtaining a flow control valve having high stability and reliability. There was room for improvement.

  The object of the present invention is to provide a flow control valve that solves the problems in the background art.

  In order to solve the above-described problems, the present invention provides an electromagnetic drive unit 2 having an outer yoke 4f disposed outside the solenoid unit 3, an inner yoke 4i disposed inside the solenoid unit 3, and an axial direction Fs front of the inner yoke 4i. A plunger portion 7 that is disposed and supports the valve body portion 6 having the valve portion 6s formed of the rubber material R, and that is displaced in the axial direction Fs in accordance with the magnitude of the drive voltage Vd applied to the solenoid portion 3; The valve body mechanism portion 5 having an elastic member 8 that elastically supports the plunger portion 7 and the valve portion 6s are disposed in front of the axial direction Fs and provided to partition the flow path J, and are opened and closed by the valve portion 6s. The surface of the valve seat portion 9s with which at least the valve portion 6s abuts when the flow control valve 1 including the orifice portion 9 formed of the metal material M having the valve seat portion 9s is provided. In sf, characterized by comprising providing a DLC (diamond-like carbon) film formation layer 10 having a predetermined thickness Ls enhancing the releasability when contact with the valve portion 6s on the surface 9sf are separated.

  In this case, according to a preferred aspect of the invention, the elastic member 8 can be provided with a leaf spring 8s that fixes the outer edge side and supports the plunger portion 7 on the center side, and the elastic member 8 includes a solenoid portion. 3 can be provided with a function of urging the plunger portion 7 in a direction in which the valve portion 6s is brought into contact with the valve seat portion 9s. The leaf spring 8s preferably has a non-linear characteristic spring load. The valve body mechanism 5 can be provided with spring adjustment mechanisms 12x and 12y that can change and adjust the spring load and / or stroke of the leaf spring 8s by an external operation. Furthermore, the surface of the valve portion 6s can be formed by a rough surface 6sc by blasting, and the silicon-based coating layer 11 by cross-linking treatment can be provided on the surface of the valve portion 6s. The silicon-based coating layer 11 can have a film thickness Lc in the range of 2 to 4.5 [μm], and the silicon-based coating layer 11 can be provided with a single layer or a multilayer structure. On the other hand, the DLC film-forming layer 10 can select the film thickness Ls in the range of 1.5 to 4.5 [μm] and the hardness in the range of Knoop hardness 500 to 1500 [HK]. The drive voltage Vd has a flow rate of 0.2 to 200 [L / min] in the range of 4 to 6 [V], provided that the differential pressure across the orifice 9 is 250 [kPa] or more. The controllable slope voltage can be set.

  According to the flow control valve 1 according to the present invention having such a configuration, the following remarkable effects can be obtained.

  (1) A DLC film-forming layer 10 having a predetermined film thickness Ls that enhances peelability when the valve portion 6s abutting against the surface 9sf is separated from at least the surface 9sf of the valve seat portion 9s abutting against the valve portion 6s. Therefore, even under severe usage environment such as heat cycle environment, it is possible to solve the problem that the control operation becomes unstable (impossible) at the start of driving (during low voltage driving), A high degree of stability and reliability in the flow control valve 1 can be ensured.

  (2) In addition to being able to contribute to downsizing of the entire flow control valve 1 by using a leaf spring 8s that fixes the outer edge side to the elastic member 8 and supports the plunger portion 7 on the center side according to a preferred embodiment, Even when the valve body 6 is supported by the elastic pressure of the leaf spring 8s and the valve 6s abuts against the valve seat 9s by a relatively strong pressure (pressure contact), the DLC film formation layer 10 is effective. Due to the action, it is possible to ensure sufficient peelability when the valve portion 6s is separated from the valve seat portion 9s.

  (3) If the elastic member 8 has a function of urging the plunger portion 7 in the direction in which the valve portion 6s is brought into contact with the valve seat portion 9s when the solenoid portion 3 is not energized, the valve portion Even in the state where the trouble that 6s is in close contact with the valve seat portion 9s is most likely to occur, the effective action of the DLC film forming layer 10 can ensure sufficient peelability when the valve portion 6s is separated from the valve seat portion 9s.

  (4) According to a preferred embodiment, if the leaf spring 8s has a non-linear characteristic spring load, the spring load of the leaf spring 8s can be balanced with respect to the suction force of the solenoid unit 3 in a wider range. This can contribute to the improvement in linearity and stability of the displacement operation of the valve portion 6s.

  (5) According to a preferred embodiment, when the valve body mechanism 5 is provided with spring adjustment mechanisms 12x and 12y capable of changing and adjusting the spring load and / or stroke of the leaf spring 8s by an external operation, the assembly is completed. Since the spring load and / or the stroke of the leaf spring 8s can be adjusted at the final stage later, the flow control valve 1 with high accuracy with little variation can be provided.

  (6) If the surface of the valve portion 6s is formed by a rough surface 6sc by blasting according to a preferred embodiment, the substantial surface area in close contact with the valve seat portion 9s can be reduced, thereby suppressing intermolecular forces. The sticking property between the valve portion 6s and the valve seat portion 9s caused by the intermolecular force and the hydrogen bond can be further reduced.

  (7) According to a preferred embodiment, if the surface of the valve portion 6s is provided with the silicon-based coating layer 11 by the crosslinking treatment, the surface of the valve portion 6s can be inactivated by surface modification by the crosslinking treatment. And the hydrogen bond, which is the cause of the sticking between the valve seat portion 9s, can be effectively suppressed. In addition, the synergistic action with the DLC film-forming layer 10 provided in the valve seat portion 9s can ensure higher peelability, which can contribute to further improvement in stability and reliability in the flow control valve 1.

  (8) If the film thickness Lc of the silicon-based coating layer 11 is selected in the range of 2 to 4.5 [μm] according to a preferred embodiment, good followability can be ensured even for deformation of the valve portion 6s. it can.

  (9) According to a preferred embodiment, if the silicon-based coating layer 11 is provided with a multilayer structure, the silicon-based coating layer 11 having higher durability and higher durability can be obtained.

  (10) When the film thickness Ls of the DLC film-forming layer 10 is selected in a range of 1.5 to 4.5 [μm] according to a preferred embodiment, when the flow control valve 1 starts driving (at low voltage driving) Therefore, from the viewpoint of selecting the film thickness Ls of the DLC film-forming layer 10, it is possible to ensure the feasibility and effectiveness of the present invention as a desirable mode (form). Can be implemented.

  (11) If the hardness of the DLC film-forming layer 10 is selected in the range of Knoop hardness of 500 to 1500 [HK] according to a preferred embodiment, the control operation can be performed when the flow control valve 1 starts to drive (during low voltage driving). Since the problem of becoming unstable (impossible) can be solved, from the viewpoint of selecting the hardness of the DLC film-forming layer 10, it can be implemented as a desirable mode (form) that can ensure the feasibility and effectiveness of the present invention.

  (12) According to a preferred embodiment, the driving voltage Vd is set to 0.2 to 200 [L] in the range of 4 to 6 [V] on condition that the differential pressure across the orifice 9 is 250 [kPa] or more. / Min] is set to a controllable gradient voltage, it is possible to ensure good followability when increasing the opening while gradually increasing the suction force.

Sectional front view showing the internal structure of a flow control valve according to a preferred embodiment of the present invention, AA line sectional view of the same flow control valve in FIG. A plan view and a cross-sectional front view of an orifice part used for the flow control valve, Cross-sectional front view including a partially extracted enlarged view of the valve portion used for the flow control valve, Action explanatory view showing the valve body mechanism part and the orifice part of the flow control valve, Usage explanation of the same flow control valve, A flow rate characteristic diagram with respect to driving voltage when the film thickness of the DLC film-forming layer in the same flow control valve is selected to be 2 [μm] A flow rate characteristic diagram with respect to a driving voltage when the film thickness of the DLC film-forming layer in the flow rate control valve is selected to be 1 [μm], A flow rate characteristic diagram with respect to the drive voltage showing the flow rate control valve and the flow rate control valve according to the background art in comparison. Flow rate characteristic diagram with respect to driving voltage of the flow control valve according to the background art,

  Next, preferred embodiments according to the present invention will be given and described in detail with reference to the drawings.

  First, the basic configuration of the flow control valve 1 according to the present embodiment will be described with reference to FIGS. 1 and 2.

  The illustrated flow control valve 1 is of a type having a normal close function, and includes an electromagnetic drive unit 2, a valve body mechanism unit 5 and an orifice unit 9 as a basic configuration as shown in FIG. The electromagnetic drive unit 2 includes a cylindrical solenoid unit 3 having a coil 22 in which a magnet wire is wound around a coil bobbin 21. Further, an outer yoke 4 f is arranged outside the solenoid unit 3 to cover the solenoid unit 3, and an inner yoke 4 i is arranged inside the solenoid unit 3. The outer yoke 4f is integrally formed in a reverse cup shape that is opened downward by a magnetic material, and the inner yoke 4i is integrally formed in a circular bar shape by a magnetic material, and the upper end surface is mechanically and magnetically coupled to the inner surface of the outer yoke 4f. To do. Therefore, the outer yoke 4 f also serves as the casing of the flow control valve 1.

  Further, a bolt 23b extending in the axial direction is integrally formed at the upper end of the inner yoke 4i, and this bolt 23b penetrates the upper end surface from the inside of the outer yoke 4f and protrudes on the upper surface, and is connected to the bolt 23b protruding outward. Screw the lock nut 23n. Thereby, the position of the inner yoke 4i in the axial direction Fs (the fully open position of the valve body portion 6 described later) can be adjusted by loosening the lock nut 23n and turning the bolt 23b. After the adjustment, the position of the bolt 23b is fixed (locked) by tightening the lock nut 23n. Thereby, the spring adjustment mechanism part 12x which can change and adjust the stroke of the leaf | plate spring 8s by operation from the outside is comprised. Providing such a spring adjustment mechanism portion 12x has an advantage that the stroke of the leaf spring 8s can be adjusted at the final stage after the assembly is completed, so that the highly accurate flow control valve 1 with less variation can be provided.

  A ring-shaped cap member 24 formed of a magnetic material is attached (screwed) to the lower end opening of the outer yoke 4f. The cap member 24 has a function of holding the coil bobbin 21 by the upper end surface and forming a part of the flow path J inside by the lower end surface, and the plunger portion 7 can be displaced in the axial direction Fs by the inner peripheral surface. The function to guide to. The electromagnetic drive part 2 is comprised by the above.

  On the other hand, the plunger portion 7 formed of a magnetic material is accommodated on the inner peripheral surface of the cap member 24. Thereby, as described above, the plunger portion 7 is supported by the inner peripheral surface of the cap member 24 so as to be displaceable in the axial direction Fs, and the upper end surface of the plunger portion 7 faces the lower end surface (front end surface) of the inner yoke 4i. To do.

  Further, the front end portion (lower end portion) of the plunger portion 7 supports the valve body portion 6. The valve body portion 6 is integrally provided with a valve portion 6s formed of a rubber material, for example, a fluorine rubber material, on the lower end surface. The lower end surface of the valve portion 6s is a flat surface, and has a function of abutting a later-described valve seat portion 9s to close the flow path J, and displacing in the axial direction Fs to vary the opening degree with respect to the flow path J. Further, the upper portion of the valve body portion 6 is formed as an attachment portion to the plunger portion 7. Thereby, it can screw with respect to the plunger part 7, and when screwing, it passes along the center side of the leaf | plate spring 8s formed in the ring shape, and this blade spring 8s is attached to the lower end part of the plunger part 7. Can be fixed. On the other hand, the outer edge side of the leaf spring 8s is fixed by being sandwiched between the fixing ring 25 and the cap member 24 which are screwed to the lower end portion of the inner peripheral surface of the cap member 24. The leaf spring 8 s constitutes an elastic member 8 that elastically supports the plunger portion 7.

  In this case, it is desirable that the leaf spring 8s has a non-linear characteristic spring load. As a result, the spring load of the leaf spring 8s can be balanced over a wider range with respect to the suction force of the solenoid part 3, so that there is an advantage that it can contribute to the improvement of linearity and stability of the displacement operation of the valve part 6s. is there.

  Further, the leaf spring 8s (elastic member 8) has a function of urging the plunger portion 7 in a direction in which the valve portion 6s is brought into contact with a later-described valve seat portion 9s when the solenoid portion 3 is not energized. Yes. Therefore, when not energized, the flow path J is closed, that is, a type having a normal close function. If the leaf spring 8 s has such a function, the valve portion 6 s can be controlled by the effective action of the DLC film-forming layer 10 even when the valve portion 6 s is most likely to be in close contact with the valve seat portion 9 s. Sufficient peelability when separating from the seat 9s can be ensured.

  In this way, if the leaf spring 8s that fixes the outer edge side and supports the plunger portion 7 on the center side is used for the elastic member 8, in addition to contributing to downsizing of the entire flow control valve 1, the valve body portion 6 Is supported by the elastic pressure of the leaf spring 8s, and even if the valve portion 6s is in contact (pressure contact) with the valve seat portion 9s by a relatively strong pressure, the valve operates due to the effective action of the DLC film formation layer 10. It is possible to ensure sufficient peelability when the portion 6s is separated from the valve seat portion 9s.

  On the other hand, a lock nack 26 is screwed to the lower end portion of the outer peripheral surface of the outer yoke 4f, and a nonmagnetic material such as a stainless steel material opened upward is formed on the outer peripheral surface of the outer yoke 4f positioned below the lock nack 26. Thus, the cup-shaped base block 27 integrally formed is screwed. Accordingly, by rotating the outer yoke 4f with respect to the base block 27, the relative position in the axial direction Fs between the base block 27 (a valve seat portion 9s described later) and the valve portion 6s can be adjusted, and the lock nack 26 The position can be fixed (locked). Thereby, the spring adjustment mechanism part 12y which can change and adjust the spring load of the leaf | plate spring 8s by the operation from the outside is comprised. Providing such a spring adjustment mechanism 12y has the advantage of providing a highly accurate flow control valve 1 with little variation because the spring load on the leaf spring 8s can be adjusted at the final stage after assembly is completed. The valve body mechanism unit 5 in the flow control valve 1 is configured as described above.

  In addition, a circular opening having a screw hole is formed at the center position of the base block 27, and a ring-shaped orifice 9 integrally formed of the metal material M is screwed and fixed to the circular opening. The orifice portion 9 is formed as a valve seat portion 9 s whose upper surface portion faces the valve portion 6 s described above, and an inner peripheral surface serves as an inlet Ji of the flow path J. As a result, the orifice part 9 having the valve seat part 9s that is disposed in front of the valve part 6s in the axial direction Fs and is provided so as to partition the flow path J and that is opened and closed by the valve part 6s is configured.

  Further, as shown in FIG. 2, the base block 27 positioned around the orifice portion 9 is formed with outlets Je of the flow path J positioned at equal intervals in the circumferential direction. As a result, a space surrounded by the valve body mechanism 5 including the cap member 24 and the inner surface of the base block 27 is formed as the flow path J. The above is the basic configuration of the flow control valve 1.

  Next, the structure of the principal part of the flow control valve 1 according to the present embodiment will be described with reference to FIGS.

  In the basic configuration described above, as described above, the flow control valve 1 is configured as a type having a normally closed function. Therefore, when the solenoid unit 3 is not energized, the valve unit 6s abuts against the valve seat unit 9s (pressure contact). ) And the flow path J is closed. As a result, when driving the flow control valve 1 that has been kept in a non-energized state, depending on the usage environment and the like, the valve portion 6s is in close contact with the valve seat portion 9s, and the control operation is performed at the start of driving (during low voltage driving). There is a problem that causes a problem that becomes unstable (impossible).

  For this reason, the flow control valve 1 according to the present embodiment increases the peelability when the valve portion 6s that contacts the surface 9sf is separated from the surface 9sf of the valve seat portion 9s that contacts the valve portion 6s. A diamond-like carbon) film-forming layer 10 is provided. FIG. 3 shows a component diagram of the orifice portion 9 provided with the valve seat portion 9 s, the upper side being a plan view of the orifice portion 9, and the lower side being a sectional front view of the orifice portion 9.

  Further, in the present embodiment, in addition to providing the DLC film forming layer 10 on the valve seat portion 9s of the orifice portion 9, the valve portion 6s in the valve body portion 6 described above is shown in FIG. The silicon-based coating layer 11 is provided on the surface of the valve portion 6s by a crosslinking process. As a result, the surface of the valve portion 6s can be inactivated by surface modification by a cross-linking treatment, so that hydrogen bonding that is a cause of sticking between the valve portion 6s and the valve seat portion 9s can be effectively suppressed. it can. In addition, the synergistic action with the DLC film-forming layer 10 provided in the valve seat portion 9s can ensure higher peelability, and thus has an advantage of contributing to further improvement in stability and reliability in the flow control valve 1.

  In this case, when the silicon-based coating layer 11 is provided, as shown in FIG. 4, the surface of the valve portion 6s is previously formed with a rough surface 6sc by blasting. As a result, a fine uneven portion is formed on the surface of the valve portion 6s, and the substantial surface area in close contact with the valve seat portion 9s can be reduced, so that the intermolecular force is suppressed and the intermolecular force and hydrogen bond are reduced. The sticking property between the valve portion 6s and the valve seat portion 9s, which is the cause, can be further reduced.

  Then, as shown in FIG. 4, a silicon-based coating layer 11 is provided on the rough surface 6sc by a crosslinking process. In this case, it is desirable to select the film thickness Lc of the silicon-based coating layer 11 in the range of 2 to 4.5 [μm]. By selecting in this way, it is possible to ensure good followability even with respect to deformation of the valve portion 6s. The silicon-based coating layer 11 may have a single layer structure, but as shown in FIG. 4, it has a two-layer structure (generally a multilayer structure) composed of a first layer 11f and a second layer 11s. As a result, it is possible to obtain the silicon-based coating layer 11 having higher coating strength and more excellent durability. In this case, the film thickness Lc can be selected in the range of 2 to 4.5 [μm] including all layers, but the film thickness of each layer is selected in the range of 2 to 4.5 [μm]. The case is not excluded.

  On the other hand, the orifice portion 9 is formed in a ring shape entirely from a stainless material (metal material) as a non-magnetic material, and as shown in FIG. 3, a large-diameter flange portion 31 provided at the lower end portion and an upper outer periphery. A screw portion 32 formed on the surface and a valve seat portion 9 s formed on the upper surface portion are provided, and the screw portion 32 is screwed onto the base block 27 described above. Further, the upper half portion of the inner peripheral surface (inlet Ji) of the orifice portion 9 is formed on the tapered surface 33 whose upper side is widened, and the inner half portion of the valve seat portion 9s on the upper surface portion continuous with the tapered surface 33. Is formed with a ring-shaped upper raised portion 34.

  In the embodiment, the film formation range W drawn by the grid lines in FIG. 3, that is, the area that covers the raised portion 34 from the intermediate position of the tapered surface 33 is selected as the film formation range W, and this film formation range W A DLC film-forming layer 10 was provided. Therefore, when forming the DLC film-forming layer 10, a portion of the orifice portion 9 excluding the film-forming formation range W is masked, and thereafter, for example, the masked orifice portion 9 is accommodated in a predetermined vapor deposition furnace. At the same time, if a known vapor deposition process is performed using a thin film formation method by plasma CVD (plasma chemical vapor deposition) or the like, a target DLC film can be formed. By performing such masking, it is possible to eliminate the formation of DLC film formation on unnecessary portions such as the screw portion 32, and therefore, adverse effects such as adversely affecting the screw function of the screw portion 32 can be avoided.

  Further, the film thickness Ls of the DLC film-forming layer 10 is preferably selected in the range of 1.5 to 4.5 [μm], and an aspect around 2 [μm] is particularly optimal. 7 and 8 show characteristic diagrams verified with respect to the film thickness. FIG. 7 is a characteristic diagram in which the film thickness Ls is selected to be 2 [μm]. A characteristic line Eic indicates a heat cycle environment, and Ein indicates a room temperature environment. FIG. 8 is a characteristic diagram in which the film thickness Ls is selected to be 1 [μm], and a characteristic line Esc indicates a heat cycle environment and Esn indicates a normal temperature environment. Further, in order to facilitate the comparison, the characteristic line Esc of FIG. 8 is shown in FIG.

  As is clear from FIG. 8 (FIG. 7), in the case of 1 [μm], the response is made from a relatively low voltage as compared to the case of 2 [μm]. Like Esc, in the initial stage of driving, the characteristic suddenly rises from around 7 [V], and the instability is not completely eliminated. However, as shown in FIG. 10, it can be confirmed that the Erc according to the background art in which the DLC film formation layer 10 is not provided is considerably improved. On the other hand, as is clear from FIG. 7, in the case of 2 [μm] in the heat cycle environment, the sudden rise at the initial stage of driving is almost eliminated.

  Therefore, from the verification results shown in FIG. 7 and FIG. 8, if the film thickness Ls is 1,5 [μm], it is assumed that there is no practical problem. On the other hand, if the film thickness Ls is too large, the properties of the valve portion 6s formed of a rubber material may be lost, and disadvantages such as the time required to form the DLC film-forming layer 10 increase. From the request of the surface, it is considered that an upper limit of about 4.5 [μm] is desirable. As a result, if the film thickness Ls of the DLC film-forming layer 10 is selected in the range of 1.5 to 4.5 [μm], the control operation can be performed at the start of driving the flow rate control valve 1 (during low voltage driving). Since the problem of becoming unstable (impossible) can be solved, from the viewpoint of selecting the film thickness Ls of the DLC film-forming layer 10, it can be implemented as a desirable mode (form) that can ensure the feasibility and effectiveness of the present invention.

  In FIG. 9, the characteristic lines Ein and Eic of the flow control valve 1 according to this embodiment provided with the DLC film-forming layer 10 having a film thickness Ls of 2 [μm] and the rubber material according to the background art are used. The characteristic line Erc when the DLC film forming layer 10 is not provided on the valve seat portion 9s is shown in an overlapped manner when the formed valve portion 6s is provided with a surface coating for reducing the adhesion. In the flow control valve 1 (Eic) according to the present embodiment, the control operation at the start of driving is considerably different from the conventional flow control valve (Erc) in which only the surface coating for reducing the adhesion force is applied to the valve portion 6s. It can be confirmed that it has been improved.

  Furthermore, the hardness of the DLC film-forming layer 10 is preferably selected in the range of Knoop hardness 500 to 1500 [HK]. If it is less than 500 [HK], it becomes too soft, and the disadvantages from the viewpoint of durability and reliability cannot be ignored. If it exceeds 1500 [HK], the properties of the valve portion 6s formed of a rubber material Disadvantages that can be lost cannot be ignored. Therefore, it is desirable that the hardness of the DLC film-forming layer 10 is selected in the range of Knoop hardness of 500 to 1500 [HK], so that the control operation can be performed when the flow control valve 1 starts driving (at the time of low voltage driving). Since the problem of becoming unstable (impossible) can be solved, from the viewpoint of selecting the hardness of the DLC film-forming layer 10, it can be implemented as a desirable mode (form) that can ensure the feasibility and effectiveness of the present invention.

  As described above, the active oxide on the surface is reduced by providing the DLC film-forming layer 10 on the surface 9sf of the orifice portion 9 using a stainless material (metal material), while the valve portion using the rubber material. It is said that the orifice part 9 (valve seat part 9s) and the valve part 6s adhere to each other because the silicon solvent is cross-linked on the surface of 6s and the surface is modified to provide an inactive state by providing the silicon film layer 11. Hydrogen bonds can be effectively suppressed.

  Next, the usage method and operation | movement of the flow control valve 1 which concern on this embodiment are demonstrated with reference to FIGS.

  The flow control valve 1 according to the present embodiment can be used for a mass flow controller 51 as shown in FIG. Reference numeral 41 indicates a gas pipe. The mass flow controller 51 is used by connecting to the midway position of the gas pipe 41. In the figure, the arrow Fg indicates the direction in which the gas flows.

  As shown in FIGS. 1 and 2, the flow control valve 1 has an inlet Ji and an outlet Je..., And thus connects the upstream side pipe in the middle position of the gas pipe 41 to the inlet Ji. Connect the downstream piping to the outlet Je. In addition, a flow sensor 52 is connected to a midway position of the gas pipe 41 located on the upstream side with respect to the flow control valve 1. Since an output signal proportional to the flow rate is obtained from the flow rate sensor 52, this output signal is applied to the input unit of the amplifier 53 and amplified, and the amplified flow rate detection signal is applied to the control unit 54. Since the flow rate command is given to the control unit 54 from the monitoring unit 55, the control unit 54 monitors the flow rate detection signal and outputs a valve control signal for making the flow rate detection signal coincide with the flow rate command. This valve control signal is applied to the input portion of the valve driver 56, and the drive voltage Vd corresponding to the valve control signal is applied from the valve driver 56 to the flow control valve 1. That is, the mass flow controller 51 detects the flow rate of the gas flowing through the gas pipe 41, and performs feedback control on the flow rate so that the detected flow rate matches the flow rate command.

  On the other hand, since the flow control valve 1 has a normal close function, when the control signal is 0 [V], it is in a non-energized state. As a result, in the flow rate control valve 1, the plunger portion 7 and the valve body portion 6 are moved downward by the elastic return force of the leaf spring 8 s, and the valve portion 6 s is formed on the upper surface portion of the orifice portion 9 as shown in FIG. 5. The valve seat 9s is in pressure contact. Therefore, in a state where the supply of gas is stopped and the gas pipe 41 is not flowing, the valve portion 6s is in pressure contact with the valve seat portion 9s for a long time. Further, since the plunger part 7 is displaced downward, the upper end surface of the plunger part 7 is separated from the lower end surface of the inner yoke 4i, and a predetermined gap (not shown) is generated between the plunger part 7 and the inner yoke 4i.

  Thereafter, it is assumed that gas supply starts and a predetermined control signal, for example, 9 [V] is applied to the flow control valve 1. As a result, the solenoid portion 7 is excited and a magnetic pole is generated in the inner yoke 4i, whereby an upward attractive force against the elasticity of the leaf spring 8s acts on the plunger portion 7. In this case, in the flow rate control valve 1 according to the present embodiment, as shown in FIG. 9, the flow rate is controlled to a flow rate of about 50 [L / min] according to normal operation even under a severe environment corresponding to the heat cycle. Is done. However, in the case of the flow control valve according to the background art shown in FIG. 10, an error state occurs in which the flow control valve does not open.

  On the other hand, when the control signal voltage increases, for example, when a control signal having a maximum voltage of 12 [V] is applied, the flow control valve 1 is fully opened and the flow rate is about 250 [L / min]. Controlled. In FIG. 5, the level Ho is a fully closed position where the valve portion 6s is displaced to the lowest position, the valve portion 6s is indicated by a solid line, and the level Hh is a fully open position where the valve portion 6s is displaced to the highest position, The valve portion 6s is indicated by a virtual line. The displacement stroke between level Ho and level Hh is Lv. Therefore, in the illustrated example, if the drive voltage Vd is gradually increased from 9 [V] to 12 [V], variable control can be performed in which the gas flow rate gradually increases in accordance with the magnitude of the drive voltage Vd. it can.

  In particular, the drive voltage Vd has a flow rate of 0.2 to 200 [L / min] in the range of 4 to 6 [V], provided that the differential pressure across the orifice 9 is 250 [kPa] or more. The controllable gradient voltage can be set, and if set in this way, it is possible to ensure good followability when increasing the opening while gradually increasing the suction force.

  As described above, the flow control valve 1 according to the present embodiment includes the outer yoke 4f disposed outside the solenoid unit 3, the electromagnetic drive unit 2 including the inner yoke 4i disposed inside the solenoid unit 3, and the axial direction of the inner yoke 4i. Plunger portion arranged in front of Fs and supporting valve body portion 6 having valve portion 6s formed of rubber material R, and displaced in axial direction Fs corresponding to the magnitude of drive voltage applied to solenoid portion 3 7 and a valve body mechanism portion 5 having an elastic member 8 that elastically supports the plunger portion 7, and the valve portion 6 s is provided in front of the axial direction Fs of the valve portion 6 s so as to partition the flow path J. In addition to having a basic configuration with the orifice portion 9 formed of a metal material M having a valve seat portion 9s that is opened and closed, in particular, at least the surface 9s of the valve seat portion 9s with which the valve portion 6s abuts. In addition, since the DLC film-forming layer 10 having a predetermined film thickness Ls that increases the releasability when the valve portion 6s that contacts the surface 9sf is separated is provided, it can be used under a severe use environment such as a heat cycle environment. However, the problem that the control operation becomes unstable (impossible) at the start of driving (at the time of low voltage driving) can be solved, and high stability and reliability in the flow control valve 1 can be secured.

  As mentioned above, although preferred embodiment was described in detail, this invention is not limited to such embodiment, It does not deviate from the summary of this invention in a detailed structure, a shape, a raw material, quantity, a numerical value, etc. It can be changed, added, or deleted arbitrarily.

  For example, although the case where the DLC film-forming layer 10 is provided in a part of the valve seat portion 9s in the orifice portion 9 by performing masking is shown, the case where it is provided in a range including other portions or the entire range is excluded. Not what you want. On the other hand, the leaf spring 8s is desirable as the elastic member 8, but the case where the elastic member 8 is replaced by another elastic member such as a coil spring is not excluded. Further, in the embodiment, the flow control valve 1 having a normally closed function is exemplified, but the present invention can be similarly applied to a type having a normally open function (fully opened when not energized). Furthermore, although it is desirable to provide the silicon-based coating layer 11 on the surface of the valve portion 6s, it is not an essential component and may be a coating layer using another coating agent.

  The flow control valve according to the present invention can be used for various applications when variably controlling the flow rate of a fluid such as gas, air, or liquid flowing through a flow path.

  DESCRIPTION OF SYMBOLS 1: Flow control valve, 2: Electromagnetic drive part, 3: Solenoid part, 4f: Outer yoke, 4i: Inner yoke, 5: Valve body mechanism part, 6: Valve body part, 6s: Valve part, 7: Plunger part, 8: Elastic member, 8s: leaf spring, 9: orifice part, 9s: valve seat part, 9sf: surface of valve seat part, 10: DLC (diamond-like carbon) film-forming layer, 11: silicon-based coating layer, Fs: axial direction , R: rubber material, M: metal material, J: flow path, Ls: film thickness, Vd: drive voltage, 11x: spring adjustment mechanism, 11y: spring adjustment mechanism

Claims (12)

  An outer yoke disposed outside the solenoid portion, an electromagnetic drive portion having an inner yoke disposed inside the solenoid portion, and a valve body having a valve portion disposed in front of the inner yoke in the axial direction and formed of a rubber material. And a valve body mechanism portion having a plunger portion that is displaced in the axial direction corresponding to the magnitude of the drive voltage applied to the solenoid portion, an elastic member that elastically supports the plunger portion, and the axial direction of the valve portion In a flow control valve that is disposed forward and is provided so as to partition the flow path, and includes an orifice portion formed of a metal material having a valve seat portion that is opened and closed by the valve portion, at least the valve portion contacts A DLC film-forming layer having a predetermined film thickness is provided on the surface of the valve seat to enhance the peelability when the valve contacting the surface is separated. Flow control valve according to claim.   The flow rate control valve according to claim 1, wherein the elastic member uses a leaf spring that fixes an outer edge side and supports a plunger portion at a center side.   The flow rate according to claim 1 or 2, wherein the elastic member has a function of urging the plunger portion in a direction in which the valve portion abuts on the valve seat portion when the solenoid portion is not energized. Control valve.   The flow control valve according to claim 2, wherein the leaf spring has a non-linear characteristic spring load.   The flow control valve according to claim 1, wherein the valve body mechanism portion includes a spring adjustment mechanism portion that can change and adjust a spring load and / or a stroke of the leaf spring by an external operation.   The flow rate control valve according to claim 1, wherein the valve portion has a surface formed by an uneven surface by blasting.   The flow rate control valve according to claim 1 or 6, wherein the valve portion is provided with a silicon-based coating layer formed by a crosslinking treatment on a surface thereof.   8. The flow rate control valve according to claim 7, wherein the silicon-based coating layer has a thickness selected in a range of 3 to 4 [μm].   The flow rate control valve according to claim 7, wherein the silicon-based coating layer is provided by a single layer or a multilayer structure.   The flow rate control valve according to claim 1, wherein the DLC film-forming layer has a film thickness selected from a range of 2 to 4 [μm].   The flow rate control valve according to claim 1 or 10, wherein the DLC film-forming layer has a hardness selected within a Knoop hardness range of 500 to 1500 [HK].   The drive voltage can control a flow rate of 0.2 to 200 [L / min] in the range of 4 to 6 [V] on condition that the differential pressure across the orifice is 250 [kPa] or more. 2. The flow rate control valve according to claim 1, wherein the flow rate control valve is set to an appropriate slope voltage.

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