JP4795806B2 - Electric valve and solenoid valve - Google Patents

Description

The present invention relates to a motor-operated valve and a solenoid valve, and in particular, a high-pressure-type motor-operated valve and a solenoid valve used in a refrigeration cycle apparatus using a CO ₂ refrigerant in which a rotor case and a plunger tube are joined to a valve housing by welding. It is about.

  As an electric valve used as a variable throttle valve or a flow control valve in a refrigeration cycle apparatus or the like, it has a valve body that opens and closes a valve port inside the valve housing, and the valve housing is made of a non-magnetic material such as stainless steel. A can-shaped rotor case is fixed, the rotor of the stepping motor is rotatably arranged in the rotor case, the stator coil unit of the stepping motor is attached to the outer peripheral portion (outside) of the rotor case, and the valve body is rotated by the rotation of the rotor. A canned electric valve that is driven to open and close is known (for example, Patent Documents 1 to 4).

  Some canned motor-operated valves have a can-shaped rotor case whose end edge is joined to the valve housing by welding such as TIG welding (for example, Patent Documents 5 to 8).

  Further, as a valve device used in a refrigeration cycle apparatus or the like, an end edge portion of a plunger tube containing a plunger of an electromagnetic solenoid device is joined to a valve housing by welding or brazing, and the electromagnetic solenoid device is joined to an outer peripheral portion of the plunger tube. There is an electromagnetic valve with a structure in which an electromagnetic coil unit is attached.

  In the motor-operated valve and electromagnetic valve as described above, the rotor case and the plunger tube are airtightly joined to the valve housing to form a sealed container (airtight container) structure in which a fluid pressure equivalent to the pressure inside the valve housing is applied. Therefore, the rotor case and the plunger tube need to ensure pressure resistance. The design pressure strength of these valve devices is determined by the allowable tensile stress (safety factor) and the case thickness of the material constituting the rotor case and plunger tube.

  In a motorized valve, the magnetic flux generated by the excitation force of the stator coil unit passes through the rotor case and acts on the rotor efficiently. In the electromagnetic valve, the magnetic flux generated by the excitation force of the electromagnetic coil unit passes through the plunger tube. Both the rotor case and the plunger tube are designed to be as thin as possible while ensuring the design pressure strength so as to efficiently act on the plunger. However, in the conventional product, the thickness of the rotor case and the plunger tube is uniform (uniform) throughout.

  By the way, the rotor case and the plunger tube are slightly different depending on the welding method such as TIG welding or laser welding, but the strength (allowable tensile stress σa ′) of the welded portion is allowed by the heat effect due to welding. ) It is generally more deteriorated. As for the deterioration tendency of the welded portion, the allowable tensile strength (σa ′) in the approximate state can be obtained from the n-th power hardening law by measuring the hardness.

  FIG. 11 illustrates the state of strength deterioration (hardness reduction) in member B due to welding of member (valve housing) A and member (rotor case) B. Generally, the hardness Ha ′ of the welded portion (molten portion) is reduced to about 0.5 to 0.7 with respect to the material hardness Ha, and the hardness Ha ′ of the welded portion is also equal to the material hardness Ha in FIG. On the other hand, it turns out that it has fallen to about 0.5.

  If this is simplified as the n-th power hardening rule and is determined as σa ′ = σa · √ (Ha ′ / Ha), the allowable stress of the welded portion of the most deteriorated portion (Ha ′ = 0.5Ha) is the allowable value of the material. It can be seen that it is about 70% of the stress. In FIG. 11, ω represents the amount of penetration of the member B in the welding width direction, and ω ′ represents the hardness recovery amount.

  This coincides with the fact that the part to be broken is the welded portion W in the breakdown pressure test of the conventional product (case thickness ts is uniform throughout).

  On the other hand, if the pressure resistance strength of the rotor case and plunger tube is designed in consideration of the decrease in allowable stress due to the effect of welding heat, the case thickness of the rotor case and the tube thickness of the plunger tube are equivalent to the allowable stress decrease. As a result, the efficiency of the magnetic flux generated by the exciting force of the coil passing through the rotor case decreases. For this reason, it is necessary to increase the excitation force of the stator coil unit and the electromagnetic coil unit.

This is a serious problem in the motor control valve and solenoid valve for controlling the refrigerant used in a high pressure state, such as a supercritical vapor compression refrigeration cycle apparatus using CO ₂ refrigerant.
JP-A-9-217853 JP-A-11-37311 JP-A-11-6577 JP 2000-297873 A JP 11-22849 A JP 2000-161520 A JP 2003-254461 A JP 2004-263841 A

  The problem to be solved by the present invention is that a rotor case, a motor operated valve that joins a plunger tube to a valve housing by welding, and a solenoid valve are transmitted by increasing the thickness of the case and the tube thickness of the magnetic flux generated by the exciting force of the coil. Compensating for a decrease in allowable stress due to the effect of welding heat without incurring a decrease in efficiency to obtain the required pressure breakdown strength, and in addition to achieving this, the material costs of the rotor case and plunger tube This is to reduce the cost by reducing the cost and increasing the productivity.

An electric valve according to the present invention includes a valve housing having a valve port, a valve body that opens and closes the valve port, a rotor case fixed to the valve housing, and an electric motor that is rotatably arranged in the rotor case. In the electric valve having a rotor and a stator coil unit of the electric motor attached to an outer peripheral portion of the rotor case, and the valve body is driven to open and close by rotation of the rotor, the rotor case has a can shape. The end edge portion is butt welded to the valve housing and fixed to the valve housing, the stator coil unit is mounted, and the rotor case is formed thinner than the weld end edge portion of the rotor case with respect to the valve housing. The coil mounting portion of the rotor case is deep drawn at least with a material thicker than the thickness of the coil mounting portion. Deep drawing products der is, and, the thickness of the ceiling portion of the rotor case is substantially the same as the thickness of the weld end.

In the motor-operated valve according to the present invention, preferably, the weld end edge portion and the coil mounting portion are smoothly connected by a taper portion whose wall thickness gradually changes, and the material is affected by the heat effect of the welding of the rotor case. The distance from the butt weld end of the weld edge where the hardness of the weld decreases to the position where the original hardness of the material is restored is called the hardness recovery amount, and the total length of the weld edge and the taper is the butt weld. Is set to a length obtained by adding a predetermined safety allowance to the hardness recovery amount of the rotor case.

  An electromagnetic valve according to the present invention includes a valve housing having a valve port, a valve body that opens and closes the valve port, a plunger tube fixed to the valve housing, and a plunger of an electromagnetic solenoid device disposed in the plunger tube. An electromagnetic coil unit of an electromagnetic solenoid device attached to an outer peripheral portion of the plunger tube, and the valve body is opened and closed by the movement of the plunger in the axial direction. The plunger tube is butt welded to the valve housing and fixed to the valve housing, the electromagnetic coil unit is mounted, and the coil mounting of the plunger tube is formed thinner than the weld end edge of the plunger tube with respect to the valve housing. Is at least as thick as the thickness of the coil mounting part. It is a thick wall thickness of material deep-drawn and deep drawn products.

In the electromagnetic valve according to the present invention, preferably, the weld end edge portion and the coil mounting portion are smoothly connected by a taper portion whose wall thickness gradually changes, and the material is affected by the heat effect of the welding of the rotor case. The distance from the butt weld end of the weld edge where the hardness of the weld decreases to the position where the original hardness of the material is restored is called the hardness recovery amount, and the total length of the weld edge and the taper is the butt weld. Is set to a length obtained by adding a predetermined safety allowance to the hardness recovery amount of the plunger tube.

Electric valve according to the present invention, the welding for the valve housing of the rotor casing or said plunger tube in the electromagnetic valve, TIG welding is a welding method of the non-consumable electrode, it can be performed by the laser welding.

  In the motor-operated valve and solenoid valve according to the present invention, the welding end edge portion of the rotor case and the plunger tube with respect to the valve housing, in other words, the thickness of the weld heat affected zone is thicker than the thickness of the coil mounting portion. Only the thickness of the affected part can be set to a thickness that allows for the reduction in allowable stress due to the effect of welding heat, and the thickness of the coil mounting part can be set to a thickness that does not include the allowable stress reduction due to welding. Without causing a decrease in transmission efficiency due to an increase in the case thickness of the magnetic flux generated by the force, it is possible to compensate for a decrease in allowable stress due to welding and obtain a required pressure breakdown strength.

The rotor case, the plunger tube is at least the coil mounting portion, Ri deep drawing and deep drawing products der thick thickness of material than the wall thickness of the coil mounting portion, further rotor casing, the rotor casing Since the thickness of the ceiling portion is substantially the same as the thickness of the weld end portion, there is no material loss due to cutting, resource saving, and material cost can be reduced as compared with a cut product. In addition, it is necessary to manufacture a die for deep drawing, but for mass-produced products, it is possible to reduce costs by reducing processing costs and increasing productivity compared to cutting.

  One embodiment of a motor-operated valve according to the present invention will be described with reference to FIG.

  The motorized valve has a valve housing 11. The valve housing 11 has a cup shape as a press-molded product made of stainless steel or the like. A fitting 13 formed by insert molding on a resin valve support guide member 12 is fixedly attached to the upper opening edge 11A of the valve housing 11 by welding.

  The valve housing 11 cooperates with the valve support guide member 12 to define a cylindrical chamber-like valve chamber 14. A lateral joint 15 that forms an inlet port and a lower joint 16 that forms an outlet port are fixedly mounted on the valve housing 11 by welding, brazing, or the like.

  A valve seat member 18 formed with a valve port 17 communicating directly with the lower joint 16 is fixedly attached to the center of the bottom of the valve housing 11 by welding, brazing or the like.

  A guide hole 19 that opens toward the valve chamber 14 is formed in the valve support guide member 12. A cylindrical valve holder 21 that constitutes a coupling assembly with the valve body 20 is fitted in the guide hole 19 so as to be slidable in the axial direction (vertical direction in FIG. 1).

  Accordingly, the valve body 20 is supported in the valve chamber 14 so as to be movable in the valve lift direction from the valve support guide member 12, and opens / closes the valve port 17 and adjusts the opening degree.

  The valve support guide member 12 has a female screw hole 22 at the upper part thereof and concentric with the guide hole 19. A male screw portion 32 formed on a rotor shaft 31 of a stepping motor 30 to be described later is screwed into the female screw hole 22.

  The rotor shaft 31 is connected at the lower end in an axial force transmission relationship in a state in which the rotor shaft 31 can rotate relative to the valve holder 21 by a spring retainer 23, a compression coil spring 24, and the like provided in the valve holder 21. The rotor shaft 31 is moved in the axial direction by rotating by the screw engagement between the male screw portion 32 and the female screw hole 22, and this axial movement is transmitted to the valve holder 21 and the valve body 20.

  A stepping motor 30 is attached to the upper portion of the valve housing 11. The stepping motor 30 is attached to an outer peripheral portion of the rotor case 33 by a rotor case 33 fixedly attached to the valve housing 11, a rotor 34 disposed in the rotor case 33 so as to be rotatable around its central axis, and a mounting bracket 45. The stator coil unit 35 is fixedly mounted.

  The rotor 34 is multipolarized at the outer periphery, and is fixedly connected to the rotor shaft 31 by a boss 34A. The stator coil unit 35 is a resin-sealed type, and has two upper and lower stages of electromagnetic coil portions 36, magnetic pole teeth 37, lead wires 38, and the like.

  A stopper mechanism 39 that limits the rotation of the rotor 34 is formed in the rotor case 33.

  Next, the shape of the rotor case 33 and the structure for attaching the rotor case 33 to the valve housing 11 will be described with reference to FIGS.

  As shown in FIG. 2, the rotor case 33 is made of stainless steel or the like and has a can shape, and a coil mounting cylindrical portion 33A (coil mounting portion) in which the stator coil unit 35 is mounted on the outer peripheral portion. A ceiling portion 33B on one side (upper side) of the coil mounting cylindrical portion 33A and closing one side of the coil mounting cylindrical portion 33A, and a welding portion on the other side (lower side) of the coil mounting cylindrical portion 33A. And an end edge portion fixed to the valve housing 11, that is, a welded edge portion 33 </ b> C.

  As shown in FIG. 3, the rotor case 33 butt-ends the tip of the welded edge 33C to the upper opening edge 11A of the valve housing 11 by a non-consumable electrode type welding method such as TIG welding or laser welding. Welded. The weld solidification portion of this butt weld is indicated by reference numeral 40 in FIG. The welded solidified part 40 is a welded solidified part formed by a non-consumable electrode type welding method, so that the welded bead that has been built up does not occur, and the wall thickness does not change. The amount of penetration in the welding width direction on the rotor case 33 side by this butt welding is indicated by the symbol ω in FIG.

  What is important in the motor-operated valve according to the present invention is that the thickness ts ′ of the welded edge portion 33C of the rotor case 33 is thicker than the thickness ts of the coil mounting cylindrical portion 33A, that is, ts ′> ts. That is. The welded edge portion 33C and the coil mounting cylindrical portion 33A are smoothly connected by a tapered portion 33D whose thickness gradually changes from ts ′ to ts in order to avoid stress concentration. In the taper portion 33 </ b> D, the degree of change in the wall thickness gradually from ts ′ to ts (taper degree) may be adapted to the degree of hardness recovery (inclination of hardness change) of the rotor case 33.

 The wall thickness ts ′ of the weld end edge portion 33C is set to a wall thickness that allows for a decrease in allowable stress due to the influence of welding heat as the wall thickness of the welding heat affected zone. For example, if the allowable stress of the weld edge 33C is reduced to about 70% of the allowable stress of the material due to the influence of welding heat, the thickness ts of the weld edge 33C is compensated for the decrease (deterioration). 'May be set to about 1.4 times the wall thickness ts of the coil mounting cylindrical portion 33A.

  Although it depends on the degree of decrease in the allowable stress of the weld heat affected zone, in the case of TIG welding, as an example, if the wall thickness ts of the coil mounting cylindrical portion 33A is about 0.6 to 0.8 mm, the weld edge portion The thickness ts ′ of 33C may be about 0.84 to 1.12 mm.

  The length h of the weld edge portion 33C due to the wall thickness ts ′ is larger than the penetration amount ω in the weld width direction on the rotor case 33 side, and the total length h ′ of the weld edge portion 33C and the taper portion 33D is the rotor case. It may be set to a length h ′ obtained by adding the safety allowance Δh to the hardness recovery amount ω ′ of 33. The safety allowance Δh may be set to a value in consideration of welding variations.

  As described above, only the weld edge portion 33C and the taper portion 33D have a thick wall thickness that allows for a decrease in allowable stress due to the influence of welding heat, and the wall thickness ts of the coil mounting cylindrical portion 33A is the allowable stress decrease due to welding. Therefore, the required pressure breakdown strength that compensates for the decrease in allowable stress due to welding can be achieved without incurring a decrease in transmission efficiency due to an increase in case thickness of the magnetic flux generated by the exciting force of the coil. can get.

  The ceiling portion 33B (see FIG. 2) of the rotor case 33 is set to have a shape and thickness that ensure the miniaturization and pressure resistance of the electric valve. When the ceiling portion 33B is hemispherical as in the present embodiment shown in FIG. 2, the wall thickness tu of the ceiling portion 33B is greater than the wall thickness ts of the coil mounting cylindrical portion 33A in order to ensure pressure resistance. It is set thick. The wall thickness tu of the ceiling part 33B may be substantially equal to the wall thickness ts' of the weld edge part 33C.

  The transition from the wall thickness ts of the coil mounting cylindrical portion 33A to the wall thickness tu of the ceiling portion 33B is smoothly performed by an appropriate radius R and a center change (R + tr) of the radius portion.

  The rotor case 33 with ts <ts ′, ts <tu, and tu≈ts ′ is made of a material having a thickness equivalent to the thickness ts ′ of the weld edge 33C as shown in FIGS. It can be manufactured by deep drawing using a press die using a die 100, a punch 101, and a wrinkle holding die 102 as described above.

  In order to obtain the thickness ts ′ of the weld edge 33C (thickness substantially equal to the thickness of the material), the die 100 is used to reduce the size of the weld edge 33C as shown in FIG. The forming part 100C is expanded in diameter as compared with the drawing part 100A of the coil mounting cylindrical part 33A, and the drawing part 100C has a mold shape that does not substantially reduce the thickness of the material in deep drawing. Yes.

  Since the wall thickness tu of the ceiling portion 33B is generally determined by the maximum entry amount of the punch 101, the maximum entry amount of the punch 101 is such that the wall thickness tu of the ceiling portion 33B is substantially equal to the wall thickness of the material. As shown in FIG. 4B, the optimum amount is set.

  Thereby, the thickness ts of the coil mounting cylindrical portion 33A, the thickness tu of the ceiling portion 33B, and the weld edge portion 33C including the flange portion (non-product portion) 33E as shown in FIG. A deep-drawn product with a wall thickness ts ′ is produced, and as shown in FIG. 5B, the flange portion 33E is cut off with a required dimension La. The rotor case 33 that satisfies ts <ts ′, ts <tu, and tu≈ts ′ is completed.

  As described above, the rotor case 33 is a deep drawing product obtained by deep drawing a material having a thickness corresponding to the wall thickness ts ′ of the welded edge portion 33C. Material costs can be reduced compared to cut products. In addition, it is necessary to manufacture a die for deep drawing, but for mass-produced products, it is possible to reduce costs by reducing processing costs and increasing productivity compared to cutting.

  Next, one embodiment of an electromagnetic valve according to the present invention will be described with reference to FIG.

  The solenoid valve has a valve housing 51. The valve housing 51 is formed of a press-molded product made of stainless steel or the like to form a valve seat member, and a valve port 52 is formed. A lower joint 54 that directly communicates with the valve port 52 to form an outlet port is fixedly mounted on the valve housing 51 by welding, brazing, or the like.

  The lower end of the plunger tube 61 of the electromagnetic solenoid device 60 is fixedly attached to the flange portion 51A of the valve housing 51 by welding. A suction element 62 is fixedly attached to the upper end of the plunger tube 61 by welding. As a result, the plunger tube 61 defines a plunger chamber 63 that also serves as a cylindrical space valve chamber between the valve housing 51 and the suction element 62 in cooperation with the valve housing 51 and the suction element 62. A lateral joint 53 that forms an inlet port is fixedly mounted on the plunger tube 61 by welding, brazing, or the like.

  A plunger 64 is provided in the plunger tube 61, that is, in the plunger chamber 63 so as to be movable in the axial direction (vertical direction in FIG. 6). A ball valve element 55 that opens and closes the valve port 52 is attached to the plunger 64.

  A compression coil spring 65 is attached between the plunger 64 and the suction element 62. The compression coil spring 65 urges the plunger 64 in a direction away from the attractor 62. Thereby, the ball valve body 55 is biased in the valve closing direction.

  An electromagnetic coil unit 67 of the electromagnetic solenoid device 60 is attached to the outer peripheral portion of the plunger tube 61 by a bolt 66. The electromagnetic coil unit 67 includes an electromagnetic coil portion 68, an outer casing 69, a lead wire 70, and the like.

  The electromagnetic solenoid device 60 attracts the plunger 64 against the spring 62 against the spring force of the compression coil spring 65 when the electromagnetic coil portion 68 is excited by energization of the electromagnetic coil portion 68. As a result, the ball valve element 55 is driven to open and close by energizing and de-energizing the electromagnetic coil portion 68.

  A welded structure between the plunger tube 61 and the valve housing 51 and a welded structure between the plunger tube 61 and the suction element 62 will be described with reference to FIGS.

  The plunger tube 61 is made of stainless steel or the like and has a cylindrical shape. One of the coil mounting cylindrical portion 61A (coil mounting portion) in which the electromagnetic coil unit 67 is mounted on the outer peripheral portion and the coil mounting cylindrical portion 61A. On the side (lower) and fixed to the valve housing 51 by welding, that is, on the lower welding edge 61B (welding edge) and on the other side (upper) of the coil mounting cylinder 61A. Thus, it has an end edge portion fixed to the suction element 62 by welding, that is, an upper weld end edge portion 61C.

  As shown in FIG. 7, the plunger tube 61 butt-ends the tip of the lower welding edge 61 </ b> B to the flange 51 </ b> A of the valve housing 51 by a non-consumable electrode type welding method such as TIG welding or laser welding. Welded. The weld solidified portion of this butt weld is indicated by reference numeral 71 in FIG. Since the weld solidified portion 71 is a weld solidified portion by a non-consumable electrode type welding method, the welded bead that has been built up does not occur, and the wall thickness does not change. The amount of penetration in the welding width direction on the plunger tube 61 side by this butt welding is indicated by the symbol ω in FIG.

  As shown in FIG. 8, the plunger tube 61 is butt welded to the attractor 62 by a non-consumable electrode type welding method such as TIG welding or laser welding. The weld solidified portion of this butt weld is indicated by reference numeral 72 in FIG. Since the weld solidified portion 72 is also a weld solidified portion by a non-consumable electrode type welding method, the welded bead that has been built up does not occur, and the wall thickness does not change. The amount of penetration in the welding width direction on the plunger tube 61 side by this butt welding is also indicated by the symbol ω in FIG.

  What is important in the electromagnetic valve according to the present invention is that the wall thickness tp ′ of the lower weld end edge 61B and the upper weld end edge 61C of the plunger tube 61 is larger than the wall thickness tp of the coil mounting cylindrical portion 61A. Is thick, that is, tp ′> tp. The lower welding edge 61B and the coil mounting cylindrical portion 61A, and the upper welding edge 61C and the coil mounting cylindrical portion 61A are each a tapered portion where the wall thickness gradually changes from tp ′ to tp to avoid stress concentration. 61D and 61E are connected smoothly. In the taper portions 61D and 61E, the degree of change in wall thickness from tp ′ to tp (taper degree) may be adapted to the degree of hardness recovery of the plunger tube 61 (inclination of change in hardness).

  The thickness tp ′ of the lower welding edge 61B and the upper welding edge 61C is set to a thickness that allows for a decrease in allowable stress due to the influence of welding heat, as the thickness of the welding heat affected zone. That is, the wall thickness is set to compensate for a decrease in allowable stress due to the influence of welding heat.

  The length h of the lower welding edge 61B and the upper welding edge 61C due to the wall thickness tp ′ is larger than the penetration amount ω on the plunger tube 61 side, and the lower welding edge 61B and the taper 61D The total length h ′ may be set to a length h ′ obtained by adding a safety allowance to the hardness recovery amount ω ′ of the plunger tube 61 (see FIG. 11). The safety allowance may be set to a value that takes into account variations in welding. The total length h ′ of the upper weld edge 61C and the tapered portion 61E may be set to a length h ′ obtained by adding a safety allowance to the hardness recovery amount ω ′ (see FIG. 11) of the plunger tube 61. The safety allowance may be set to a value that takes into account variations in welding.

  Thus, only the lower weld edge 61B, the upper weld edge 61C, that is, the thickness tp 'of the weld heat affected zone, has a thick wall thickness that allows for a reduction in allowable stress due to the weld heat effect. Since the wall thickness tp of the mounting cylindrical portion 61A can be reduced to a thickness that does not include the allowable stress reduction due to welding, without causing a decrease in transmission efficiency due to an increase in the case thickness of the magnetic flux generated by the exciting force of the coil, The required pressure fracture strength that compensates for the reduction in allowable stress due to welding can be obtained.

  In this embodiment, since the valve housing 51 is also a sheet metal product, the thickness th ′ of the flange portion 51A, which is a welded portion with the plunger tube 61, is considered in consideration of a decrease in allowable stress due to the influence of welding heat. It is thicker than the wall thickness th of the other part (non-welded part) of the valve housing 51.

  Plunger tube 61 of tp <tp ′ is made of a material having a thickness equivalent to the thickness tp ′ of the lower welding edge 61B and the upper welding edge 61C, for deep drawing by a die, punch, or wrinkle holding die. It can be manufactured by deep drawing using a press die.

  In order to obtain the thickness tp ′ (thickness substantially equal to the thickness of the material) of the lower welding edge 61B, the die has a drawing portion at that portion compared to the drawing portion of the coil mounting cylindrical portion 61A. In order to obtain the wall thickness tp ′ of the upper welded edge portion 61C (thickness substantially equal to the wall thickness of the material), the punch forming portion of the punch is a coil mounting cylindrical portion. A die which is reduced in diameter as compared with the 61A drawing forming portion, and in the drawing forming portions of the lower welding end edge portion 61B and the upper welding end edge portion 61C, the material thickness does not substantially decrease in the deep drawing processing. It has a shape.

  Thereby, the wall thickness tp of the coil mounting cylindrical portion 61A including the flange portion (non-product portion) 61F and the bottom portion (non-product portion) 61J as shown in FIG. A deep-drawn product having a wall thickness tp ′ of 61B and the upper welded edge 61C is obtained, and as shown in FIG. 9B, the flange 61F and the bottom 61J are cut off at the required dimension Lb. The plunger tube 61 satisfying tp <tp ′ is completed.

  As described above, the plunger tube 61 is a deep drawing product obtained by deep drawing a material having a thickness corresponding to the wall thickness tp ′ of the lower welding edge 61B and the upper welding edge 61C. There is no material loss due to, saving resources and reducing material costs compared to cut products. In addition, it is necessary to manufacture a die for deep drawing, but for mass-produced products, it is possible to reduce costs by reducing processing costs and increasing productivity compared to cutting.

  In the motor-operated valve and the electromagnetic valve according to the above-described embodiments, the valve housings 11 and 51 are each formed by a press-molded product. However, the valve housing includes a valve housing main body made of a cast product and a machined product, and a valve housing main body. In this case, the rotor case and the plunger tube may have the same configuration as that of the above-described embodiment. Butt welded to the lower lid member.

  An embodiment in which the present invention is applied to an electric valve of a type in which a valve housing is constituted by an assembly of a valve housing body and a lower lid member will be described with reference to FIG. 9, parts corresponding to those in FIGS. 1 to 3 are denoted by the same reference numerals as those in FIGS. 1 to 3, and description thereof is omitted.

  In this embodiment, the valve housing 81 includes a valve housing main body 82 made of a cast product and a machined product, and a dish-shaped lower lid member 83 made of a press-formed product fixedly mounted on the upper portion of the valve housing main body 82 by welding or the like. It consists of an assembly.

  The rotor case 33 is butt welded with a welding edge 33C to the upper edge 83A of the lower lid member 83 standing by a non-consumable electrode type welding method such as TIG welding or laser welding. The weld solidification portion of this butt weld is indicated by reference numeral 40.

  Also in this embodiment, the thickness of the welded edge portion 33C of the rotor case 33 is thicker than the thickness of the coil-mounted cylindrical portion 33A of the rotor case 33, and the welded edge portion 33C and the coil-mounted cylindrical portion 33A are: In order to avoid stress concentration, the connection is smoothly made by the tapered portion 33D in which the wall thickness gradually changes.

  As a result, only the thickness of the weld edge 33C is thick enough to allow for a reduction in allowable stress due to the effect of welding heat, and the thickness of the coil mounting cylindrical portion 33A is thin and does not include the allowable stress reduction due to welding. Even in this embodiment, the required pressure breakdown strength that compensates for the decrease in allowable stress due to welding can be obtained without incurring a decrease in transmission efficiency due to an increase in case thickness of the magnetic flux generated by the exciting force of the coil. It is done.

  In this embodiment, a cylindrical male screw member 84 is fixedly mounted on the upper portion of the valve housing main body 82, and a female screw member 85 integral with the rotor 34 is screw-engaged with the male screw member 84. The valve body 20 is connected to a female screw member 85 by a valve shaft 86 that is long in the axial direction, and is moved in the axial direction by the female screw member 85 being driven to rotate by the rotor 34.

  In each of the embodiments described above, a material having a thickness equivalent to the thickness ts ′ of the welding edge 33C, or a thickness tp ′ of the lower welding edge 61B and the upper welding edge 61C is equivalent. The case where the rotor case 33 and the plunger tube 61 in which the coil mounting cylindrical portion 33A having the wall thickness ts and the coil mounting cylindrical portion 61A having the wall thickness tp are formed by deep drawing is described.

  However, according to the present invention, a material having a thickness greater than the thickness ts ′ of the weld edge 33C, or a thickness greater than the thickness tp ′ of the lower weld edge 61B and the upper weld edge 61C. In addition to the coil mounting cylindrical portion 33A having the wall thickness ts and the coil mounting cylindrical portion 61A having the wall thickness tp, the welding end edge 33C having the wall thickness ts 'and the lower welding end of the wall thickness tp' The edge 61B and the upper welding edge 61C can also be applied to the case where the rotor case 33 and the plunger tube 61 formed by deep drawing are used.

  In addition, the present invention is not limited to compensating for a decrease in allowable stress due to thermal effects caused by non-consumable electrode type welding methods such as TIG welding and laser welding, but by other welding methods or by brazing. Are equally applicable.

It is a longitudinal cross-sectional view which shows one embodiment by this invention. It is a longitudinal cross-sectional view which shows the rotor case of the motor operated valve by one Embodiment. It is an expanded sectional view of the welding part of the valve housing and rotor case of the motor operated valve by one Embodiment. (A), (b) is sectional drawing which shows the deep drawing process of the press type | mold used for manufacture of the rotor case of the motor operated valve by one embodiment, and a rotor case. (A), (b) is sectional drawing which shows the rotor case by deep drawing. It is a longitudinal cross-sectional view which shows one embodiment by this invention. It is an expanded sectional view of the welding part of the valve housing and plunger tube of an electromagnetic valve by one embodiment. It is an expanded sectional view of the welding part of the attractor and plunger tube of a solenoid valve by one embodiment. (A), (b) is sectional drawing which shows the plunger tube by deep drawing. It is a longitudinal cross-sectional view which shows other embodiment of the motor operated valve by this invention. It is explanatory drawing which shows the hardness characteristic of a welding part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Valve housing 11A Upper opening edge 12 Valve support guide member 13 Mounting bracket 14 Valve chamber 15 Horizontal joint 16 Lower joint 17 Valve port 18 Valve seat member 19 Guide hole 20 Valve body 21 Valve holder 22 Female screw hole 23 Spring retainer 24 Compression coil Spring 30 Stepping motor 31 Rotor shaft 32 Male thread part 33 Rotor case 33A Coil mounting cylindrical part 33B Ceiling part 33C Welding edge part 33D Taper part 33E Flange part 34 Rotor 34A Boss part 35 Stator coil unit 36 Electromagnetic coil part 37 Magnetic pole teeth 38 Lead Wire 39 Stopper mechanism 40 Weld solidification part 45 Mounting bracket 51 Valve housing 51A Flange part 52 Valve port 53 Lateral joint 54 Lower joint 55 Ball valve body 60 Electromagnetic solenoid device 61 Plunger tube 61A Coil-mounted cylindrical part 1B Lower Weld Edge 61C Upper Weld Edge 61D, 61E Tapered 61F Flange 61J Bottom 62 Suction Element 63 Plunger Chamber 64 Plunger 65 Compression Coil Spring 66 Bolt 67 Electromagnetic Coil Unit 68 Electromagnetic Coil 69 Outer Spare 70 Lead Wire 71, 72 Weld solidification part 81 Valve housing 82 Valve housing main body 83 Lower lid member 83A Upper edge part 84 Male thread member 85 Female thread member 86 Valve shaft 100 Dies 100A, 100C Drawing part 101 Punch 102 Wrinkle holding mold

Claims (6)

A valve housing having a valve port; a valve body that opens and closes the valve port; a rotor case fixed to the valve housing; a rotor of an electric motor rotatably disposed in the rotor case; An electric valve having a stator coil unit of the electric motor attached to an outer peripheral portion, and the valve body is driven to open and close by rotation of the rotor;
The rotor case has a can shape, and an end edge portion is butt welded to the valve housing and fixed to the valve housing, the stator coil unit is mounted, and a weld end of the rotor case to the valve housing coil mounting portion of the rotor casing which is formed by thinner than the edges, at least, Ri deep drawing products der was deep drawing a thick wall thickness of the material than the wall thickness of the coil mounting portion, and, The motor operated valve in which the thickness of the ceiling portion of the rotor case is substantially the same as the thickness of the welded end portion . The weld edge and the coil mounting part are smoothly connected by a taper part with a gradually changing thickness, and the weld edge where the hardness of the material decreases due to the thermal effect of welding of the rotor case. The distance from the butt weld end to the position where the original hardness of the material recovers is called the hardness recovery amount, and the total length of the weld end edge portion and the taper portion is the hardness recovery amount of the rotor case by the butt welding, The motor-operated valve according to claim 1, wherein the motor-operated valve is set to a length including a predetermined safety allowance. The weld relative to the valve housing of the rotor case, the non-consumable electrode of the TIG welding is a welding method, according to claim 1 or 2 motorized valve according is due to laser welding. A valve housing having a valve port; a valve body for opening and closing the valve port; a plunger tube fixed to the valve housing; a plunger of an electromagnetic solenoid device disposed in the plunger tube; and an outer peripheral portion of the plunger tube An electromagnetic coil unit of an electromagnetic solenoid device attached to the solenoid valve, wherein the valve body is opened and closed by the axial movement of the plunger.
The plunger tube has an end edge butt welded to the valve housing and is fixed to the valve housing, and is attached to the electromagnetic coil unit, and is formed thinner than a welded end edge of the plunger tube with respect to the valve housing. The solenoid valve is a deep drawing product in which the coil mounting portion of the plunger tube is deep drawn at least with a material having a thickness larger than the thickness of the coil mounting portion. The weld edge and the coil mounting part are smoothly connected by a taper part with a gradually changing thickness, and the weld edge where the hardness of the material decreases due to the thermal effect of welding of the rotor case. The distance from the butt weld end to the position where the original hardness is recovered is called the hardness recovery amount, and the total length of the weld end edge portion and the taper portion is the hardness recovery amount of the plunger tube by the butt welding, The solenoid valve according to claim 4, wherein the solenoid valve is set to a length including a predetermined safety allowance. The weld relative to the valve housing of the plunger tube, TIG welding is a welding method of the non-consumable electrode, an electromagnetic valve according to claim 4, wherein is due to laser welding.

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