JP2019062180A - Solenoid actuator and manufacturing method thereof - Google Patents

Abstract

To improve the mounting freedom of a solenoid actuator to a driving target device.SOLUTION: A solenoid actuator 100 that moves a plunger 17 in the axial direction by magnetic force generated by energizing a coil 11 and drives a drive unit 3 of a driving target device 110 by the movement of the plunger 17 includes a stator 12 accommodating the plunger 17, a yoke 10 accommodating the coil 11 disposed on the outer peripheral side of the stator 12, and an attachment portion 20 connected to the stator 12 and attached to a screw hole 2d of the driving target device 110, and the outer periphery of the attachment portion 20 is disposed inside the outer periphery of the yoke 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a solenoid actuator and a method of manufacturing the solenoid actuator.

  Patent Document 1 discloses an electromagnetic actuator that generates a magnetic field by passing a current through a coil that constitutes an electromagnet, and causes an armature to reciprocate by the magnetic field. The housing for housing the electromagnetic actuator is attached to the internal combustion engine main body by bolts (fixing members (20)).

JP 2001-230116 A

  In the electromagnetic actuator device described in Patent Document 1, a flange portion for attaching a bolt to the housing (8a) is provided. The flange portion is provided to project radially outward more than the outer periphery of the electromagnetic actuator (4), so the radial dimension of the electromagnetic actuator device including the electromagnetic actuator (4) and the housing (8a) is increased. It will That is, the electromagnetic actuator device described in Patent Document 1 has a problem that the mounting freedom is low because the mounting target is limited to the driving target device having a large mounting space.

  The present invention has been made in view of the above problems, and an object thereof is to improve the degree of freedom in attaching a solenoid actuator to a device to be driven.

  A first invention relates to a solenoid actuator, which includes a stator for accommodating a plunger, a yoke for accommodating a coil disposed on the outer peripheral side of the stator, and an attachment portion connected to the stator and attached to a screw hole of a device to be driven. , And the outer periphery of the mounting portion is disposed inside the outer periphery of the yoke.

  In the first aspect of the invention, the radial dimension of the mounting portion attached to the drive target device can be made smaller than the radial dimension of the yoke.

  A second invention is characterized in that the mounting portion is formed of a steel material in which at least chromium is added to iron which is a main component.

  A third invention is characterized in that the steel material contains 0.4% by mass or more of nickel.

  A fourth invention is characterized in that the steel material contains 1.6% by mass or more of nickel and 0.15% by mass or more of molybdenum.

  A fifth invention is characterized in that the mounting portion is formed of a steel material having a Rockwell hardness of 55 HRC or more when cooled from a temperature of 800 ° C. or more to room temperature.

  A sixth invention is characterized in that the mounting portion is formed of a material having mechanical properties such that a decrease in Rockwell hardness is 10 HRC or less when cooled from a temperature of 800 ° C. or more to room temperature.

  A seventh invention is characterized in that the mounting portion is formed of a material different from that of the stator and having a higher resistance to annealing softening than the material of the stator.

  In the second to seventh inventions, when, for example, a steel material subjected to a quenching and tempering treatment is selected as the material of the mounting portion, the mounting portion is heated to a high temperature by welding or the like and then cooled to room temperature. Thus, the hardness of the mounting portion can be suppressed from decreasing. For this reason, it is possible to prevent the decrease in the mounting strength of the solenoid actuator with respect to the drive target device.

  An eighth invention is characterized in that the stator includes a first stator core integrally formed with the mounting portion and a second stator core connected to the first stator core.

  In the eighth invention, since the mounting portion and the first stator core are integrally formed into a single member, the number of parts can be reduced as compared to the case where the mounting portion and the first stator core are separate members.

  A ninth invention is a method of manufacturing the above-mentioned solenoid actuator, which comprises a heat treatment step of heat treating the material of the mounting portion so that the strength of the material of the mounting portion is equal to or greater than a predetermined strength. And a welding step of manufacturing the tubular assembly by connecting the stators by welding, wherein the predetermined strength is a solenoid in which the strength of the material of the mounting portion reduced by the thermal effect in the welding step is attached to the driven device It is characterized in that it is set so as to have the strength required for the actuator or more.

  In the ninth invention, since an inexpensive material can be used as the material of the mounting portion, the cost of the solenoid actuator can be reduced.

  According to the present invention, it is possible to improve the mounting freedom of the solenoid actuator with respect to the device to be driven.

It is a sectional view of a solenoid valve, and shows a state where electricity is supplied to a coil. It is a flowchart which shows the manufacture procedure of a solenoid actuator. It is a continuous cooling transformation curve figure of SNCM439. It is a graph which shows about the heat influence with respect to a test material. It is sectional drawing of the solenoid actuator which concerns on the modification 4 of this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The solenoid actuator is an electromagnetic actuator that moves a plunger in the axial direction by a magnetic force generated by energizing a coil, and drives a drive unit of a device to be driven by the movement of the plunger. In the following embodiments, a solenoid actuator used for a solenoid valve that controls the flow rate of working fluid will be described.

  With reference to FIG. 1, the whole structure of the solenoid valve 1 provided with the solenoid actuator 100 which concerns on embodiment of this invention is demonstrated.

  The solenoid valve 1 includes a solenoid actuator 100 and a valve device 110 which is a device to be driven in which a spool 3 as a drive unit is driven by the solenoid actuator 100. The solenoid valve 1 controls the flow rate of hydraulic fluid as a working fluid that is led from a fluid pressure supply source (not shown) to a fluid pressure device etc. (not shown). The working fluid is not limited to the working oil, and may be other noncompressible fluid or compressible fluid.

  The valve device 110 includes a bottomed cylindrical valve body 2, a spool 3 as a valve body movably provided in the valve body 2, and an urging member provided in the valve body 2 and urging the spool 3. And a coil spring 9 of

  In the valve body 2, an inflow passage 2a and an outflow passage 2b as valve passages through which hydraulic fluid flows are formed in line in the axial direction. The inflow passage 2a is in communication with the inside of the valve body 2 and in communication with a fluid pressure supply source via a pipe or the like (not shown). The outflow passage 2b communicates with the inside of the valve body 2 and communicates with the hydraulic equipment etc. via a piping etc. not shown.

  The spool 3 has a smaller diameter than the first land portion 4 and the second land portion 5 sliding along the inner peripheral surface of the valve body 2 and the first land portion 4 and the second land portion 5, and the first land portion It has a small diameter portion 6 connecting the fourth land portion 5 and the tip portion 7 in contact with the shaft 16 of the solenoid actuator 100.

  At the end of the first land portion 4, a spring accommodating recess 4a in which a part of the coil spring 9 is accommodated is formed. The second land portion 5 slides along the inner peripheral surface of the valve body 2 to adjust the opening degree of the inflow passage 2a.

  The small diameter portion 6 is smaller in diameter than the first land portion 4 and the second land portion 5, and forms an annular fluid chamber 8 with the inner circumferential surface of the valve body 2. The fluid chamber 8 communicates with the inflow passage 2a and the outflow passage 2b, and guides the hydraulic oil having passed through the inflow passage 2a to the outflow passage 2b.

  The coil spring 9 is interposed in a compressed state between the spring accommodation recess 4 a of the first land portion 4 in the spool 3 and the bottom 2 c of the valve body 2. The coil spring 9 biases the spool 3 to resist the movement of the plunger 17 when the coil 11 of the solenoid actuator 100 is energized. That is, the coil spring 9 biases the spool 3 in the direction in which the second land portion 5 opens the inflow passage 2a (right direction in FIG. 1).

  The opening end of the valve body 2 is provided with a screw hole 2d to which a mounting portion 20 of a solenoid actuator 100 described later is attached. An internal thread is formed on the inner peripheral surface of the screw hole 2d, and an external thread formed on the mounting portion 20 of the solenoid actuator 100 is screwed.

  The solenoid actuator 100 is attached to the valve device 110 and drives the spool 3 of the valve device 110 in the axial direction.

  The solenoid actuator 100 is provided with a cylindrical yoke (case) 10, a coil 11 disposed on the outer peripheral side of the stator 12 to generate a magnetic force when current flows, and provided inside the coil 11 and excited by the magnetic force of the coil 11. A stator 12, a shaft (push rod) 16 inserted through the stator 12 and movable in the axial direction, a plunger 17 fixed to the shaft 16, and a mounting portion 20 connected to an end of the stator 12 And.

  The yoke 10 is formed of a magnetic material such as soft iron and has a cylindrical portion 10 a with a bottom and a end plate 10 b that closes the opening of the cylindrical portion 10 a. A through hole through which the stator 12 is inserted is provided in each of the bottom portion of the cylindrical portion 10a and the end plate 10b.

  The coil 11 is accommodated in the yoke 10. The coil 11 is molded by a resin material (not shown) or attached to a resin bobbin (not shown). The coil 11 generates a magnetic force when a current supplied through a terminal (not shown) flows.

  The stator 12 is provided inside the coil 11. The stator 12 has a cylindrical first stator core 13, a bottomed cylindrical second stator core 14 disposed at a predetermined distance from the first stator core 13, and a space between the first stator core 13 and the second stator core 14. And a spacer 18 disposed to face the end face of the plunger 17. The first stator core 13, the second stator core 14, and the spacer 18 are formed of a steel or a magnetic material such as electromagnetic soft iron having a carbon (C) content of 10% by mass or less, and the cylindrical body 15 is stainless steel, copper alloy And other nonmagnetic materials.

  The spacer 18 is fitted inside the first stator core 13 and fixed at a predetermined position. The spacer 18 is a cylindrical member, and the shaft 16 is inserted into the inside. The shaft 16 is formed of a nonmagnetic material such as stainless steel or copper alloy.

  A plunger chamber 19 in which the plunger 17 is accommodated is formed by the inner surface of the first stator core 13 which is the inner surface of the stator 12, the inner surface of the cylindrical body 15, the inner surface of the second stator core 14, and the end surface of the spacer 18. The end face of the spacer 18 serves as an attraction surface 19 a on which the plunger 17 is attracted to the stator 12 by the magnetic force of the coil 11. In other words, the end face of the plunger chamber 19 on the side of the first stator core 13 is the suction surface 19 a.

  The shaft 16 is disposed movably along the axial direction with the plunger 17. The tip of the shaft 16 contacts the tip 7 of the spool 3. Thus, the spool 3 moves with the movement of the shaft 16.

  The plunger 17 is formed of a magnetic material such as soft iron. The plunger 17 is accommodated in the plunger chamber 19 and fixed to the shaft 16 by a method such as caulking so as not to cause displacement of the shaft 16. The plunger 17 moves in the plunger chamber 19 by the attraction force acting on the suction surface 19 a which is one end of the plunger chamber 19 by the magnetic force of the coil 11.

  Next, the operation of the solenoid valve 1 will be described.

  In the non-energized state in which no current flows in the coil 11, the attraction force does not act on the plunger 17, and the spool 3 is attached in the direction to open the inflow passage 2a by the biasing force of the coil spring 9 (right direction in FIG. 1). Be driven. Therefore, the inflow passage 2a and the outflow passage 2b communicate with each other via the fluid chamber 8, and the passage of hydraulic oil is permitted.

  When a current flows through the coil 11, for example, a magnetic path of yoke 10 → second stator core 14 → plunger 17 → first stator core 13 and spacer 18 → yoke 10 is formed, and plunger 17 is attracted toward attraction surface 19a. . The cylindrical body 15, which is a nonmagnetic material, restricts the flow of magnetic flux so as to form a magnetic path in which the magnetic flux is led from the second stator core 14 to the first stator core 13 and the spacer 18 via the plunger 17. It functions as a restriction unit. Further, the end of the first stator core 13 in contact with one end face of the cylindrical body 15 and the end of the second stator core 14 in contact with the other end face of the cylindrical body 15 are each formed into a tapered shape. . Thereby, the size of the magnetic path is limited, and the magnitude of the current flowing through the coil 11 and the thrust of the plunger 17 have a proportional relationship.

  As described above, when an electric current flows through the coil 11 to generate a magnetic force, the plunger 17 is excited, and an attracting force in a direction (left direction in FIG. 1) directed to the attraction surface 19a acts on the plunger 17. The plunger 17 moves toward the suction surface 19a by such a suction force.

  Due to the attraction force acting on the spool 3, a force acting in the direction to compress the coil spring 9 acts on the spool 3. Therefore, the spool 3 moves to a position where the attraction force and the biasing force of the coil spring 9 are balanced. As the magnitude of the current supplied to the coil 11 increases, the attraction between the plunger 17 and the attraction surface 19a increases. Therefore, the spool 3 moves in the direction of compressing the coil spring 9 against the biasing force of the coil spring 9 as the value of the current supplied to the coil 11 increases.

  When the current value for energizing the coil 11 is increased and the spool 3 is moved against the biasing force of the coil spring 9, the inflow passage 2 a is gradually closed by the second land portion 5, and the inflow passage 2 a to the fluid chamber 8 The open area of the For this reason, the flow rate of the hydraulic oil introduced to the fluid chamber 8 through the inflow passage 2a is reduced.

  When the current value for energizing the coil 11 is further increased to increase the stroke amount of the plunger 17 toward the suction surface 19a, the inflow passage 2a is completely closed by the second land portion 5 as shown in FIG. Thus, the communication between the inflow passage 2a and the outflow passage 2b is cut off.

  As described above, the solenoid valve 1 controls the value of the current supplied to the coil 11 to move the spool 3 in the axial direction, thereby adjusting the flow rate of the hydraulic fluid introduced from the inflow passage 2a to the outflow passage 2b.

  Next, the configuration of the mounting portion 20 will be described in detail.

  The mounting portion 20 is a cylindrical member, and is fixed to the first stator core 13 by being welded to the first stator core 13. That is, the mounting portion 20 is mechanically and thermally connected to the first stator core 13. The mounting portion 20 includes a threaded portion 21 formed on the outer periphery of an external thread engaged with a female screw in the threaded hole 2 d of the valve body 2, a flange portion 23 contacted to the end face of the valve body 2, and a threaded portion And a seal holding portion 22 for holding an oil seal (O ring) 30 between the flange portion 21 and the flange portion 23.

  The seal holding portion 22 is formed in a groove shape so that the outer diameter thereof is smaller than the outer diameter of the screw portion 21 and the outer diameter of the flange portion 23. The outer diameter of the flange portion 23 is set to be larger than the outer diameter of the screw portion 21 and smaller than the outer diameter of the yoke 10. That is, the outer periphery of the mounting portion 20 is disposed inside the outer periphery of the yoke 10. In other words, the flange portion 23 does not protrude radially outward from the outer peripheral surface of the yoke 10. Therefore, the dimension in the radial direction can be reduced as compared with a solenoid actuator provided with a flange portion for bolt attachment projecting radially outward from the outer peripheral surface of the yoke 10. That is, according to the present embodiment, since the radial dimension of the mounting portion 20 of the solenoid actuator 100 is reduced, the space required for mounting on the valve device 110 can be reduced.

  Next, a method of manufacturing the solenoid actuator 100 will be described.

  As shown in FIG. 2, the method of manufacturing the solenoid actuator 100 includes a heat treatment process S100, a preparation process S110, a welding process S120, and an assembly process S130.

  When the solenoid actuator 100 is used for the valve device 110 of high pressure specification, high mounting strength is required for the screw portion 21 of the mounting portion 20. For this reason, it is preferable that the material of the attaching part 20 is heat-treated (quenching and tempering treatment). In the heat treatment step S100, the material of the mounting portion 20 is heated to a predetermined temperature, and quenching treatment is performed to quench the material after a predetermined time. Thereafter, the material of the mounting portion 20 is heated again to raise the temperature to a predetermined temperature, and a tempering process of cooling after a predetermined time is performed.

  In preparation process S110, the structural member of the solenoid actuator 100 containing the 1st stator core 13 shown in FIG. 1, the 2nd stator core 14, the cylindrical body 15, and the mounting part 20 to which heat processing was performed by said heat processing process S100 is prepared.

  In the welding step S120, the first stator core 13, the cylindrical body 15, and the second stator core 14 are connected by welding. That is, the first stator core 13 and the second stator core 14 are connected via the cylindrical body 15. Furthermore, the first stator core 13 and the mounting portion 20 are connected by welding. As the welding method, various welding methods such as laser welding, electron beam welding, TIG welding, furnace brazing, and torch brazing are adopted. Instead of welding, the first stator core 13, the cylindrical body 15, the second stator core 14 and the mounting portion 20 may be joined by solid phase joining method such as electric heating joining, diffusion joining, friction welding (friction welding), etc. .

  In the welding step S120, a cylindrical assembly 40 formed by welding the first stator core 13, the cylindrical body 15, the second stator core 14, and the mounting portion 20 is produced. The substantially cylindrical first stator core 13, the cylindrical body 15, the second stator core 14, and the mounting portion 20 are connected such that their central axes coincide with each other.

  The first stator core 13, the cylindrical body 15, the second stator core 14 and the mounting portion 20 are thermally connected by welding, so each portion is heated to, for example, 800 ° C. or more by heat accompanying welding. Sometimes. The heated material is cooled, for example, to room temperature (about 27 ° C.) at an average cooling rate of 200 ° C./sec or more.

  In the assembling step S130, the cylindrical assembly 40 is inserted into the yoke 10 in which the coil 11 is accommodated, and a nut 41 made of a magnetic material such as soft iron is attached to an external thread formed at the end of the second stator core 14. The yoke 10 and the cylindrical assembly 40 are fastened so as to sandwich the yoke 10 between the nut 41 and the flange portion 23 of the mounting portion 20. Thus, the solenoid actuator 100 is completed.

  The external thread on the outer periphery of the threaded portion 21 of the mounting portion 20 and the external thread on the outer periphery of the end of the second stator core 14 may be formed after the welding step S120 or formed before the welding step S120. You may

  Next, the material of the mounting portion 20 will be described.

  As described above, when the solenoid actuator 100 is used for the valve device 110 of high pressure specification (for example, withstanding pressure of 5 MPa or more), the mounting portion is capable of holding high axial force for a long time without damaging the screw portion 21 20 requires high mounting strength.

  Therefore, as described above, the high-strength material subjected to the heat treatment (quenching and tempering treatment) in the heat treatment step S100 is used as the material of the mounting portion 20. In this case, the material of the mounting portion 20 is cooled at a predetermined cooling rate (for example, 200 ° C./sec or more) after the temperature once rises to a predetermined temperature (for example, 800 ° C. or more) due to the thermal effect in the welding step S120. It will be For this reason, the hardness of the material of the attaching part 20 will fall. Therefore, in order to suppress a decrease in hardness due to heating and cooling in welding step S120, a material having high annealing resistance (equivalent to temper softening resistance) may be selected as the material of mounting portion 20. preferable.

  In the present embodiment, a steel material obtained by adding at least 0.4 mass% of chromium (Cr) to iron (Fe) as the main component is selected as the material of the mounting portion 20. The steel material selected as the material of the mounting portion 20 has an annealing softening resistance compared to the materials of the first stator core 13, the second stator core 14 and the spacer 18 which are constituent members of the stator 12 (magnetic materials constituting the stator 12) Is high.

  As steel materials selected as the material of the mounting portion 20, for example, JIS standard SCr steel materials (chromium steel materials), JIS standard SCM steel materials (chromium molybdenum steel materials), JIS standards SNCM steel materials (nickel chromium molybdenum steel materials) It is preferable to select any one of the above. Each of these steel materials is a material having a higher resistance to annealing softening than the magnetic material constituting the stator 12. The high annealing resistance is the difference ΔX from the hardness X2 when the material having a predetermined hardness X1 is kept at a high temperature atmosphere for a predetermined time and then cooled to room temperature (about 27 ° C.) at a predetermined cooling rate. (.DELTA.X = X1-X2) is small.

  For example, SNCM steel materials have higher annealing softening resistance than SCM steel materials and SCr steel materials, and the decrease in hardness due to the influence of heat in the welding step S120 can be effectively suppressed. FIG. 3 is a continuous cooling transformation curve diagram (CCT curve diagram) of JIS standard SNCM439. The continuous cooling transformation curve diagram is a diagram in which the transformation start and end points of phase transformation at various cooling rates are plotted on the vertical axis with time on the horizontal axis in the transformation process of the alloy in the continuous cooling process.

  As shown in FIG. 3, after holding a test piece of SNCM 439 having a Rockwell hardness (HRC) of H0 for about 10 minutes in an atmosphere of 800 ° C. or higher, room temperature (about 27 ° C.) at an average cooling rate of 1 ° C./sec. The Rockwell hardness (HRC) when cooled down to H2 is H2. In this case, the decrease in Rockwell hardness is about 3.5 to 4 HRC. In addition, after holding a test piece of SNCM439 with a Rockwell hardness (HRC) of H0 for about 10 minutes in an atmosphere of 800 ° C. or higher, it was cooled to room temperature (about 27 ° C.) at an average cooling rate of 0.4 ° C./sec. When the Rockwell hardness (HRC) is H3. The difference (H2-H3) between H2 and H3 is about 0.4 HRC. Further, the difference between H3 and H4 in the figure (H3-H4), and the difference between H4 and H5 in the figure (H4-H5) are respectively about 0.1 HRC. In addition, after holding the test piece of SNCM439 whose Rockwell hardness (HRC) is H0 for about 10 minutes in an atmosphere of 800 ° C. or higher, it was cooled to room temperature (about 27 ° C.) at an average cooling rate of 2.5 ° C./sec. When the Rockwell hardness (HRC) becomes H1. The difference between H1 and H2 (H1-H2) is about 1 HRC.

  Thus, SNCM 439 has mechanical properties such that the Rockwell hardness decreases by 10 HRC or less when cooled at a temperature of 800 ° C. or more to room temperature (about 27 ° C.) at an average cooling rate of 200 ° C./h or more. doing. In addition, SNCM439 has mechanical properties such that the Rockwell hardness decreases by 5 HRC or less when cooled at a temperature of 800 C or more to room temperature (about 27 C) at an average cooling rate of 0.4 C / sec or more. doing.

  The SNCM-based steel material contains 0.4% by mass or more and 0.4% by mass or less of nickel (Ni) and 0.4% by mass or less and 0.4% by mass or less of molybdenum (Mo) in addition to chromium (Cr) of 0.4% by Since it contains 15 mass% or more and 0.7 mass% or less and has high annealing softening resistance as compared with SCM steel materials and SCr steel materials, it is suitable as the material of the mounting portion 20.

  The SCM-based steel material contains 0.15% by mass or more and 0.45% by mass or less of molybdenum (Mo) in addition to chromium (Cr) of 0.9% by mass or more and 1.5% by mass or less, and is an SCr type It has high resistance to annealing and softening as compared to steel. Further, the SCr-based steel material contains chromium (Cr) of 0.9% by mass or more and 1.2% by mass or less, and has a higher annealing softening resistance than the magnetic material constituting the stator 12.

  Therefore, as the material of the mounting portion 20, various steel materials such as SCr steel, SCM steel, SNCM steel, etc. containing 0.4 mass% or more and 4.8 mass% or less of chromium (Cr) should be adopted. Can.

  In particular, it is preferable to adopt SNCM 439 in which the decrease in Rockwell hardness due to the thermal effect in the welding step S120 is suppressed to 10 HRC or less and the Rockwell hardness after the welding step S120 is 55 HRC or more. SNCM 439 is carbon (C) 0.36 mass% or more and 0.43 mass% or less, silicon (Si) 0.15 mass% or more and 0.35 mass% or less, manganese (Mn) 0.60 mass% or more 0.90 mass% or less, phosphorus (P) 0.030 mass% or less, sulfur (S) 0.030 mass% or less, chromium (Cr) 0.6 mass% or more and 1.0 mass% or less, nickel (Ni) is contained at 1.6% by mass or more and 2.0% by mass or less, molybdenum (Mo) is contained by 0.15% by mass or more and 0.3% by mass or less, and the balance is iron (Fe) and inevitable impurities. As described above, SNCM 439 contains 0.6 mass% or more of chromium (Cr), 1.6 mass% or more of nickel (Ni), and 0.15 mass% or more of molybdenum (Mo). , With high annealing softening resistance.

  According to the embodiment described above, the following effects can be obtained.

  (1) Since the outer periphery of the mounting portion 20 is disposed inside the outer periphery of the yoke 10, the radial dimension of the mounting portion 20 attached to the valve device 110 which is the device to be driven is the radial dimension of the yoke 10 Can be kept small. Therefore, according to the present embodiment, it is possible to provide the solenoid actuator 100 with a high degree of freedom of mounting that can be used not only for the valve device 110 having a large mounting space but also for the valve device 110 having a small mounting space.

  (2) The mounting portion 20 is formed of a steel material in which at least chromium (Cr) is added to iron (Fe) which is the main component. For this reason, even if the mounting portion 20 is heated to a high temperature in the manufacturing process or the like and then cooled, the reduction in hardness can be suppressed. As a result, it is possible to prevent a decrease in the attachment strength of the attachment portion 20 attached to the valve device 110 by screwing. Therefore, according to the present embodiment, it is possible to provide the solenoid actuator 100 that can be used not only for the low pressure valve apparatus 110 under low pressure load but also for the high pressure valve apparatus 110 under high pressure load. it can.

  As described above, according to the present embodiment, it is possible to provide a highly versatile solenoid actuator 100 that has a wide range of drive target devices to be attached.

  The following modifications are also within the scope of the present invention, and it is possible to combine the configuration shown in the modification with the configuration described in the above embodiment or to combine the configurations described in the following different modifications. It is.

(Modification 1)
The material of the mounting portion 20 is not limited to a steel material to which chromium (Cr) is added. The annealing softening resistance can be enhanced by the addition of carbide-forming elements such as molybdenum (Mo), tungsten (W), vanadium (V) and the like. Therefore, various steel materials in which a carbide-forming element such as molybdenum (Mo), tungsten (W), vanadium (V) or the like is added to iron (Fe) as the main component can be selected as the material of the mounting portion 20 . Among these chromium (Cr) -free steel materials, a high softening resistance material having mechanical properties such that the Rockwell hardness decreases by 10 HRC or less when cooled from a temperature of 800 ° C. or more to room temperature (about 27 ° C.) It is preferable to select Furthermore, it is preferable to select a steel material having a Rockwell hardness of 55 HRC or more when cooled to a temperature of 800 ° C. or more to room temperature (about 27 ° C.).

(Modification 2)
Although the said embodiment demonstrated the example using alloy steel materials, such as SCr steel materials which add alloy elements, such as chromium (Cr), to carbon steel materials, SCM steel materials, and SNCM steel materials as a material of the attaching part 20. The present invention is not limited to this. For the material of the mounting portion 20, a carbon steel material in which the alloying element (additional element) does not meet the predetermined lower limit (Cr: 0.3 mass%, Mo: 0.08 mass%, Ni: 0.3 mass%) May be For example, carbon steel (SC material) for machine structures, such as JIS S45C etc. which carbon (C) is contained as 0.42 mass% or more and 0.48 mass% or less as a material of attachment part 20 can be used. Moreover, as a material of the attaching part 20, SB materials, such as JIS SB410 and SB450M, can also be used. When using SC material and SB material as the material of the attachment portion 20, the decrease in Rockwell hardness is 10 HRC or less when cooled from a temperature of 800 ° C. or more to room temperature (about 27 ° C.) in the welding step S120. Preferably, the cooling rate is adjusted. Further, it is preferable to adjust the cooling rate so that the Rockwell hardness becomes 55 HRC or more when cooled from a temperature of 800 ° C. or more to room temperature (about 27 ° C.).

(Modification 3)
In the above embodiment, an example in which the material of the mounting portion 20 is heat-treated (quenched and tempered) in the heat treatment step S100 has been described. However, depending on the heat treatment conditions, the strength of the material of the mounting portion 20 is lower than the strength (required strength) necessary for the solenoid actuator 100 mounted on the valve device 110 due to the thermal effect of reheating and cooling in the welding step S120. There is a risk of

  Therefore, in the present modification, the heat treatment step S100 is performed so that the necessary tensile strength σ0 as the necessary strength is secured even if the strength of the material of the mounting portion 20 is reduced by the thermal effect in the welding step S120. In addition, predetermined | prescribed experiment is performed prior to heat processing process S100 which produces the material of the attaching part 20. FIG. In this experiment, a plurality of test materials Ma, Mb, Mc, and Md are manufactured by changing the heat treatment conditions, and each of the test materials Ma, Mb, Mc, and Md is adopted as a material of the mounting portion 20 in the welding step S120. Acquire strength reduction characteristics due to thermal effects.

  FIG. 4 is a graph showing the thermal effect on the test material. In FIG. 4, the vertical axis represents the tensile strength σ of the test material, and the horizontal axis represents time t. The time point t0 corresponds to the time when the welding process S120 is started, and the time t1 corresponds to the time when the temperature of the material of the mounting portion 20 decreases to room temperature after the welding process S120 is completed.

  In experiment, welding process S120 which produces the cylindrical assembly 40 by producing the attaching part 20 by test material Ma, Mb, Mc, and Md and connecting the attaching part 20 and the stator 12 by welding is performed. In the experiment, instead of actually performing the welding step S120, the test materials Ma, Mb, Mc, and Md may be given the same amount of heat as the welding step S120. That is, when an experiment can be performed under the same environment as the welding step S120, it is not necessary to manufacture the cylindrical assembly 40.

  The tensile strength σ (the tensile strength σ at time t0) before welding is performed, and the tensile strength σ (the tensile strength σ at time t1) after the welding is performed and the temperature of the test material decreases to room temperature , From the tensile test. Thereby, the fall characteristic of strength of each test material Ma, Mb, Mc, and Md is obtained.

  Next, among the plurality of test materials Ma, Mb, Mc, Md, those having the tensile strength σ at time t1 of the required tensile strength σ0 or more are selected (selection step). Further, among the selected test materials, one having the lowest tensile strength σ at time point t0 or time point t1 is specified as a reference material (reference material specifying step). Further, the tensile strength σ at time t0 of the reference material is set as the reference tensile strength σs (reference strength setting step).

  Hereinafter, the case where test materials Ma, Mb, Mc, and Md are used will be described as an example. The test material Ma is heat treated (quenched and tempered) to set the tensile strength σ at time t0 to σa1 (> σ0). In this test material Ma, the tensile strength σ decreases with time from time t0, and the tensile strength σ at time t1 becomes σa2. The σa2 is smaller than the required tensile strength σ0, which is a strength required as a material of the mounting portion 20 (σa2 <σ0). Therefore, the test material Ma is not suitable as the material of the mounting portion 20.

  The test material Mb is heat treated (quenched and tempered) to set the tensile strength σ at time t0 to σb1 (> σa1). The tensile strength σ of this test material Mb decreases with the lapse of time from time t0, and the tensile strength σ at time t1 becomes σb2. σ b 2 is equal to the required tensile strength σ 0 which is the strength necessary for the material of the mounting portion 20 (σ b 2 = σ 0). For this reason, the test material Mb is suitable as a material of the mounting portion 20.

  The test material Mc is heat treated (quenched and tempered) to set the tensile strength σ at time t0 to σc1 (> σb1), and the test material Md is heat treated (quenched and tempered) to be tensile strength σ at time t0 It is set as σd1 (> σc1). The test materials Mc and Md each have a tensile strength σ at time t1 greater than the required tensile strength σ0. Therefore, the test materials Mc and Md are suitable as the material of the mounting portion 20.

  Therefore, in the selection step, among the test materials Ma, Mb, Mc, Md, the test materials Mb, Mc, Md having the required tensile strength σ0 or more at the tensile strength σ at time t1 are suitable as the material of the mounting portion 20 Is selected as Furthermore, in the reference material specifying step, the test material Mb having the lowest tensile strength σ at time point t0 or time point t1 among the selected test materials Mb, Mc, Md is specified as the reference material. Then, in the reference strength setting step, the tensile strength σb1 at time t0 of the test material Mb which is the reference material is set as the reference tensile strength σs. The reference tensile strength σs can be represented by the sum of the required tensile strength σ0 and the strength reduction amount Δσ0 (= σb1−σb2) due to the thermal effect of welding on the reference material (σs = σ0 + Δσ0).

  In heat treatment process S100 which concerns on this modification, the material of the attachment part 20 is heat-processed so that the intensity | strength of the material of the attachment part 20 may become more than reference | standard tensile strength (sigma) s which is predetermined predetermined intensity. In other words, in the heat treatment step S100, the material of the attachment portion 20 is heat-treated so that the strength of the material of the attachment portion 20 is equal to or higher than the required tensile strength σ0 plus the strength reduction amount Δσ0 of the reference material. Do.

  In this modification, heat treatment conditions (heating of material (heat and temper treatment) in heat treatment (quenching and tempering treatment) such that tensile strength σ after heat treatment becomes equal to or higher than reference tensile strength σs by quenching and tempering (tempering) in heat treatment step S100. Adjust the time, heating temperature, cooling rate etc.). When the heat treatment step S100 is completed, a welding step S120 of manufacturing the cylindrical assembly 40 by connecting the mounting portion 20 and the stator 12 by welding is performed as in the above embodiment.

  In the conventional heat treatment, it was not assumed that the material after the heat treatment would be reheated. That is, in the conventional heat treatment, tempering treatment has been performed for the purpose of removing residual stress, adjusting hardness and toughness, on the assumption that the material after heat treatment is used as it is for a product. On the other hand, in the present modification, the heat treatment conditions of the tempering treatment are set in consideration of the fact that reheating and cooling in the welding step S120 are performed in advance. That is, in this modification, it can be said that the mounting portion 20 having a tensile strength σ of not less than the necessary tensile strength σ0 is produced through reheating and cooling in the welding step S120.

  As described above, in the present modification, heat treatment is performed on the material of the mounting portion 20 so that the strength of the material of the mounting portion 20 is equal to or greater than the predetermined reference tensile strength σs in the heat treatment step S100. The reference tensile strength σs is the strength (tensile strength σ) of the material of the mounting portion 20 reduced by the thermal effect in the welding step S120, the strength (necessary tensile strength) necessary for the solenoid actuator 100 to be mounted to the valve device 110 It is set to be greater than or equal to σ 0). For this reason, even when the strength of the material of the mounting portion 20 is reduced by the welding step S120, the required strength (required tensile strength σ0) can be reliably ensured.

  Moreover, according to such a modification, since inexpensive carbon steel materials such as SC material can be used as the material of the mounting portion 20, the cost of the solenoid actuator 100 can be reduced.

(Modification 4)
In the above embodiment, the mounting portion 20 is a separate member formed of a material different from that of the stator 12 and is described by way of example attached to the end portion of the first stator core 13 of the stator 12 by welding. It is not limited to.

  As shown in FIG. 5, the attachment portion 20B may be formed of the same material as the first stator core 13B of the stator 12B. The mounting portion 20B of the solenoid actuator 100B and the first stator core 13B according to the present modification are a single member 60B formed integrally. Since the mounting portion 20B and the first stator core 13B are integrally formed into a single member 60B, the number of components is smaller than in the case where the mounting portion 20 and the first stator core 13 are separate members (the above embodiment). It can be reduced.

  Since the mounting portion 20B is integrally connected to the first stator core 13B, when welding the first stator core 13B, the cylindrical body 15, and the second stator core 14B, heat is transmitted from the welding portion, for example, in the welding step S120. The temperature of the mounting portion 20B rises due to the thermal effect. For this reason, as a material of the single member 60B composed of the first stator core 13B and the attachment portion 20B, it is preferable to select a material having high resistance to annealing and softening as described above. Further, as described in the third modification, in consideration of the thermal influence in the welding step S120, the strength of the material of the single member 60B is equal to or greater than a predetermined reference tensile strength σs. Heat treatment process S100 which heat-treats the material of 60B may be performed. As a result, since inexpensive carbon steel materials such as SC material can be used as the material of the single member 60B, the cost of the solenoid actuator 100 can be reduced.

  The second stator core 14B may be formed of the same material as that of the single member 60B, or may be formed of a material different from that of the single member 60B. When the second stator core 14B is formed of a material different from that of the single member 60B, the material of the second stator core 14B may be, for example, a steel or a magnetic material such as electromagnetic soft iron having a carbon (C) content of 10% by mass or less. Can be adopted. Since these materials are excellent in processability, the manufacturing cost of the solenoid actuator 100B can be reduced. Also, the plunger thrust can be improved.

(Modification 5)
Moreover, although the said embodiment demonstrated the example which the material of the attaching part 20 consists of material with high annealing softening resistance compared with the material of the stator 12, this invention is not limited to this. If the strength of the mounting portion 20 after annealing can be secured, the material of the stator 12 may be made higher than the material of the mounting portion 20 by the annealing softening resistance. However, if the material of the stator 12 is a material having a high resistance to annealing and softening, for example, the magnetic properties become worse compared to electromagnetic soft iron. Therefore, it is preferable to use the mounting portion 20 as a material having high annealing and softening resistance, and the stator 12 as a magnetic material such as steel or electromagnetic soft iron having a carbon (C) content of 10% by mass or less. That is, the mounting portion 20 is preferably made of a material having a higher resistance to annealing and softening than the material of the stator 12.

(Modification 6)
Although the said embodiment demonstrated the example which the attachment part 20 cools to room temperature (about 27 degreeC) at the average cooling rate of 200 degrees C / sec or more in welding process S120, but this invention relates to this It is not limited. Even if the temperature of the mounting portion 20 does not rise to 800 ° C. or more in the welding step S120, it is possible to suppress a decrease in hardness in the heating and cooling processes. The higher the average cooling rate, the less the reduction in hardness can be.

(Modification 7)
Although the said embodiment demonstrated the example in which the solenoid actuator 100 was attached to the valve apparatus 110 as a drive object apparatus, this invention is not limited to this. The solenoid actuator 100 can be attached to various devices to be driven and used.

  Hereinafter, the configuration, operation, and effects of the embodiment of the present invention will be collectively described.

  The solenoid actuators 100 and 100B are solenoid actuators that move the plunger 17 in the axial direction by the magnetic force generated by energizing the coil 11, and drive the spool 3 of the valve device 110 by the movement of the plunger 17. Mounting portions 20 and 20B connected to the screw holes 2d of the valve device 110 connected to the stators 12 and 12B to be accommodated, the yoke 10 to accommodate the coil 11 disposed on the outer peripheral side of the stators 12 and 12B, and the stators 12 and 12B And the outer periphery of the attachment portions 20 and 20B is disposed inside the outer periphery of the yoke 10.

  In this configuration, the radial dimension of the mounting portion 20 attached to the valve device 110 can be made smaller than the radial dimension of the yoke 10. As a result, it is possible to improve the mounting freedom of the solenoid actuators 100 and 100B with respect to the valve device 110.

  In the solenoid actuator 100, 100B, the mounting portion 20, 20B is formed of a steel material in which at least chromium is added to iron as a main component.

  In the solenoid actuator 100, 100B, the steel contains 0.4% by mass or more of nickel.

  In the solenoid actuator 100, 100B, the steel material contains 1.6% by mass or more of nickel and 0.15% by mass or more of molybdenum.

  The solenoid actuator 100, 100B is formed of a steel material having a Rockwell hardness of 55 HRC or more when the mounting portion 20, 20B is cooled from a temperature of 800 ° C. or more to room temperature.

  The solenoid actuator 100, 100B is formed of a material having mechanical properties such that the decrease in Rockwell hardness is 10 HRC or less when the mounting portion 20, 20B cools from a temperature of 800 ° C. or more to room temperature.

  In the solenoid actuator 100, the mounting portion 20 is formed of a material different from that of the stator 12 and is higher in annealing softening resistance than the material of the stator 12.

  In these configurations, when, for example, a steel material subjected to a quenching and tempering treatment is selected as the material of the mounting portions 20 and 20B, the mounting portions 20 and 20B are heated to a high temperature by welding or the like and then cooled to room temperature. It can suppress that the hardness of attachment part 20, 20B falls as a result. For this reason, the fall of the attachment intensity to valve apparatus 110 of solenoid actuator 100, 100B can be prevented.

  The solenoid actuator 100B has a first stator core 13B in which a stator 12B is integrally formed with the mounting portion 20B, and a second stator core 14B connected to the first stator core 13B.

  In this configuration, since the mounting portion 20B and the first stator core 13B are integrally molded into a single member 60B, the number of parts is reduced compared to the case where the mounting portion 20 and the first stator core 13 are separate members. it can.

  The method of manufacturing the solenoid actuator 100, 100B comprises a heat treatment step of heat treating the material of the mounting portion 20 such that the strength of the material of the mounting portion 20, 20B is equal to or greater than a predetermined strength (reference tensile strength σs) And welding step S210 of manufacturing the cylindrical assembly 40 by connecting the mounting portion 20 and the stators 13 and 13B by welding, and the predetermined strength is reduced by the thermal effect in the welding step S120. The strength of the material is set to be equal to or higher than the strength required for the solenoid actuator 100 attached to the valve device 110 (the required tensile strength σ0).

  In this configuration, an inexpensive material can be used as the material of the mounting portions 20 and 20B, so the cost of the solenoid actuators 100 and 100B can be reduced.

  As mentioned above, although the embodiment of the present invention was described, the above-mentioned embodiment showed only a part of application example of the present invention, and in the meaning of limiting the technical scope of the present invention to the concrete composition of the above-mentioned embodiment. Absent.

2d · · · screw hole, 3 · · · spool (drive portion), 10 · · · Yoke, 11 · · · · · 12 12B · · · Stator, 13, 13 B · · · 1st stator core, 14, 14 B ... 2nd stator core, 17 ... plunger, 20, 20B ... attachment part, 40 ... cylindrical assembly, 100, 100B ... solenoid actuator, 110 ... valve device (drive target device )
S100 ... heat treatment process, S 120 ... welding process

Claims (9)

A solenoid actuator which moves a plunger in the axial direction by a magnetic force generated by energizing a coil, and drives a drive unit of a device to be driven by the movement of the plunger,
A stator for accommodating the plunger;
A yoke for accommodating the coil disposed on the outer peripheral side of the stator;
And an attaching portion connected to the stator and attached to a screw hole of the device to be driven.
An outer periphery of the attachment portion is disposed inward of an outer periphery of the yoke. In the solenoid actuator according to claim 1,
The solenoid actuator, wherein the mounting portion is formed of a steel material in which at least chromium is added to iron as a main component. In the solenoid actuator according to claim 2,
The said steel material contains 0.4 mass% or more of nickel. The solenoid actuator characterized by the above-mentioned. In the solenoid actuator according to claim 3,
The steel material includes 1.6% by mass or more of nickel and 0.15% by mass or more of molybdenum. The solenoid actuator according to any one of claims 1 to 4.
The solenoid actuator, wherein the mounting portion is formed of a steel material having a Rockwell hardness of 55 HRC or more when cooled from a temperature of 800 ° C. or more to room temperature. The solenoid actuator according to any one of claims 1 to 5,
The solenoid actuator, wherein the mounting portion is formed of a material having mechanical properties such that a decrease in Rockwell hardness is 10 HRC or less when cooled from a temperature of 800 ° C. or more to room temperature. The solenoid actuator according to any one of claims 1 to 6.
The solenoid actuator, wherein the mounting portion is formed of a material different from the stator and having a higher resistance to annealing softening than the material of the stator. The solenoid actuator according to any one of claims 1 to 6.
The stator is
A first stator core integrally formed with the mounting portion;
And a second stator core connected to the first stator core. A method of manufacturing a solenoid actuator according to any one of claims 1-8.
A heat treatment step of heat treating the material of the mounting portion so that the strength of the material of the mounting portion is equal to or greater than a predetermined strength set in advance;
Welding the tubular assembly by connecting the mounting portion and the stator by welding.
The predetermined strength is set such that the strength of the material of the mounting portion, which is reduced due to the thermal influence in the welding process, is greater than or equal to the strength necessary for the solenoid actuator mounted on the driven device. Method of manufacturing a solenoid actuator.

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