JP2006258300A - Shut-off valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shut-off valve capable of realizing high airtight reliability, stable action performance with small electric power, operation durability and economical competitiveness. <P>SOLUTION: The shut-off valve is provided with an inner pan-like part 66c of a partition wall 66 made of metal; a recessed part 72b formed on a lid 72; a rotation shaft 69 made of metal; and a radial/thrust common rolling bearing 76 stored in the recessed part 72b. The radial/thrust common rolling bearing 76 supports the rotation shaft 69 in a radial direction and supports a retaining means 70 of a rotor 71 in a thrust direction. Axis accuracy of the rotor 71 is high and stable action performance with small electric power can be realized. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention uses a safety valve (international patent classification F16K 17/36) that operates according to an external situation and uses an electric motor as an operation means (international patent classification F16K 31/04), in particular, a gas shut-off device that prevents a gas accident in advance. More specifically, the present invention relates to a shutoff valve used as a shutoff mechanism, and more specifically, a motor that performs a shutoff return operation of the flow path by moving the valve body forward or backward relative to a valve seat formed in the flow path is used as a power source. It relates to the shut-off valve.

  In order to prevent gas accidents, various types of safety devices have been used in the past.In particular, when the flow rate sensor built in the gas meter monitors the gas flow rate and the microcomputer determines that the gas usage status is abnormal, Microcomputer-equipped gas with a battery power source that shuts off the gas with a shut-off valve built in the gas meter when the status of sensors such as earthquake sensors, gas pressure sensors, gas alarms, carbon monoxide sensors, etc. The gas meter with built-in shut-off device (hereinafter abbreviated as “microcomputer meter”) has been promoted due to advantages such as safety, ease of gas piping, and low price, and almost all households have been implemented.

  In addition, the ratio of centralized monitoring micrometers that have a telemeter function that centrally monitors the gas flow rate information measured by the flow sensor using a telephone line will increase, and the convenience of information terminals will increase. It has been demanded.

  In this central monitoring type microcomputer meter, etc., gas can be shut off and restored by electric energy from the battery installed in the microcomputer meter so that gas can be shut off and restored by simple electric switch operation or remote operation by telephone line etc. On the other hand, a shut-off valve that does not require energy is required to maintain the open and closed states.

  As the drive system for this shut-off valve, the one that used an electromagnetic solenoid has been the mainstream. However, in recent years, a relatively strong closing force and return force can be realized. The shut-off valve as a source is drawing attention, and in particular, the shut-off valve having an airtight partition with the rotor inside the gas flow path and the stator outside the gas flow path is attracting attention because it can be easily attached to the gas flow path. Yes.

  A conventional shut-off valve will be described below.

  Conventionally, a shut-off valve using a PM type stepping motor of this type as a drive source has been disclosed (for example, see Patent Document 1 and Patent Document 2).

As shown in FIG. 5, the shut-off valve described in this patent document 1 has a cup-shaped casing 6 with a flange by aluminum impact molding or the like that becomes an airtight partition, and a stator 4 is mounted on the outer periphery of the casing 6. Then, an outer bush 3 which is a radial sliding bearing made of a synthetic resin such as polyacetal, which is self-lubricating, is fitted into the opening of the casing 6, and the stud 5 is eccentrically integrated with the outer bush 3 to the front. The inner bush 12 which is a radial sliding bearing made of a synthetic resin having a self-lubricating property such as polyacetal is inserted into the casing 6, and a lead screw 17 is inserted at the tip of the outer bush 3 and the inner bush. The male screw portion 17a projects forward from the outer bush 3 and is supported rotatably in the forward and reverse directions. A rotor 16 is attached to the lead screw 17 so as to face the stator 4, and three or more balls 19 are arranged between two washers 20, 21 arranged between the rotor 16 and the outer bush 3. A first thrust load rolling bearing 18 arranged above is inserted, and a second thrust load rolling bearing 24 similarly configured is inserted between the rotor 16 and the inner bush 12, and the second An elastic elastic member 30 having a spring washer shape is inserted between the thrust load rolling bearing 24 and the inner bush 12, and the valve seat holding member 26 and the valve seat are engaged with the stud 5 and screwed into the male screw portion 17a. The valve body 25 comprised by 27 is arrange | positioned.

  A disc-shaped stepped flange 2 is fitted to the outer periphery of the outer bush 3, and an annular flat plate flange 7 welded to the stator 4 is fitted to the outer periphery of the casing 6. The stepped flange 2 and the flat plate flange 7 are fixed to each other and sandwich the flange portion of the outer bush 3 and the flange portion of the casing 6 at the same time. Furthermore, between the stepped flange 2 and the flat plate flange 7, an elastic seal member 8 having a circular cross section made of elastic synthetic resin is assembled in a state of being pressed in the front-rear direction.

  The operation of the shut-off valve configured as described above will be described below.

  When the gas is abnormally used, the rotor 16 is rotated forward by energization from a control unit (not shown), the lead screw 17 rotates in the forward direction, and the valve body 25 is moved from the lead screw 17 side to the valve seat 28 side. By moving forward and coming into contact with the valve seat 28, the flow path is closed to shut off the fluid. Further, when returning this, the lead screw 17 is rotated in the reverse direction by energization from the control unit, the valve body 25 is moved backward from the valve seat 26 side to the lead screw 17 side, the flow path is opened, and the fluid is opened. The supply of was resumed.

  Since this type of shut-off valve is disposed in the flow path so that fluid pressure such as gas is urged in the valve closing direction, a stronger thrust is required at the instant of valve opening, and the rotor 16 and the outer bush 3 However, since the first thrust roller bearing 18 receives the thrust load, torque loss as a frictional force is reduced.

  Moreover, the shut-off valve described in Patent Document 2 is shown in FIG. This shut-off valve has a configuration substantially the same as that of the shut-off valve of FIG. 5 except that there is no inner bush and outer bush that are radial slide bearings, and a rolling bearing 44 disposed on the lead screw 50 of the rotor 42, Reference numeral 45 denotes a generally available radial ball bearing, the position of which is regulated by a flange 46, which is a metal plate welded to both ends of the stator 41, and a rear cover 47. The airtight partition is not a cup-shaped casing but both ends are open. The seal members 48 and 49 are disposed between both ends of the pipe 43 and the flange 46 and the rear cover 47, and the stud 53 is press-fitted and fixed to the flange 46 by a metal rod processed with a header. is there.

  The rolling bearings 44 and 45 can also receive a thrust load, and can reduce torque loss as a frictional force when the valve is opened.

The operation of this shut-off valve is the same as that of the shut-off valve in FIG.
Japanese Patent Laid-Open No. 11-2351 (page 4-5, FIG. 1) Japanese Patent Laid-Open No. 9-210237 (page 3-5, FIG. 4)

  A shut-off valve that uses this type of PM type stepping motor as a drive source is required to maintain the axis of the rotor and ensure the coaxiality with the hermetic partition for stable operation performance and low power.

Moreover, it is generally attached to a gas meter installed outdoors and exposed to severe temperature changes from temperatures exceeding 50 ° C under direct sunlight in summer to temperatures below -20 ° C in severe winter season. The parts on the passage side are the above-mentioned severe temperature changes in an organic environment such as fuel gas, which is a low molecular weight hydrocarbon, and active gas, which is a purified impurity such as moisture, hydrogen sulfide, sulfur dioxide, etc. In addition, the atmosphere side is exposed to severe conditions such as high-temperature and high-humidity environments close to the saturation humidity outdoors and dew condensation in the gas meter. Among them, high gas-tight reliability is required so that no gas leaks during the service period (generally 10 years) of the gas meter.

  That is, it is necessary to achieve both the rotor shaft center holding accuracy and high airtight reliability.

  However, the conventional shut-off valve shown in FIG. 5 positions the radial direction of the lead screw 17 that is the rotating shaft by the outer bush 3 and the inner bush 12 that are radial slide bearings made of synthetic resin. Since the difference in coefficient of linear expansion from the metal lead screw 17 is large, it is necessary to set a large hole diameter so as not to lock the lead screw 17 at low temperatures. As a result, the outer bush 3, the inner bush 12 and the lead screw 17 Since the radial clearance of the resin is large, and the self-lubricating synthetic resin such as polyacetal has a high molding shrinkage rate, it is difficult to increase the dimensional accuracy at the time of molding. There was a problem that accuracy would be lowered.

  At the same time, the shut-off valve of FIG. 5 is relatively easy to wear because the outer bush 3 and the inner bush 12 which are radial slide bearings are made of synthetic resin, and the wear powder easily adheres due to static electricity or the like. Is worn between the washers 20, 21 and the ball 19 and adheres to the outer surface of the ball 19, the ball 19 is obstructed from smooth rotation, The functions of the first thrust load roller bearing 18 and the second thrust load roller bearing 24 are reduced, and the operation becomes unstable.

  Further, in the conventional shut-off valve shown in FIG. 6, the axial center of the rotor 16 is held by the flange 46, the rear cover 47, and the radial roller bearings 44, 45 that are metal plates. There is no difference in the coefficients and the radial clearance can be reduced. On the other hand, the axial center is determined by the accuracy of the welding process that is performed while positioning the flange 46, the rotor 41, the rear cover 47 and many other parts. Since the process is also a process of making the pipe 43, the flange 46, and the rear cover 47 hermetic, the manufacturing process requires careful attention and has a problem of high cost.

  At the same time, since there are two sealing members 48 and 49, the airtight reliability is lowered.

  In the shut-off valve shown in FIG. 6, the surface of the welded portion 54 of the flange 46 and the stator 41 is in the gas on the surface on the flow path side and in the air on the other surface, so that the fuel gas, moisture contained in the gas, hydrogen sulfide In addition, it is exposed to severe conditions such as temperature changes in an organic environment such as active gas, which is a purified impurity such as sulfur dioxide, and outdoor high-temperature and high-humidity environments close to saturated humidity, and condensation in gas meters. In the welded portion, strain remains between the metal structures, and there is a risk of breakage due to the occurrence of intergranular corrosion and stress corrosion cracking. When the caulking portion 54 breaks, there is a problem that gas leakage occurs.

  At the same time, since there are two sealing members 48 and 49, the airtight reliability is lowered.

  In addition, since the shut-off valve in FIG. 6 employs expensive radial roller bearings as the bearings 44 and 45, there is a problem that the whole is expensive.

  In view of such conventional problems, the present invention has high hermetic reliability capable of withstanding humidity stress, temperature stress, chemical stress, etc. in long-term use, and stable operation performance with low power because of high accuracy of holding the rotor shaft center. Another object of the present invention is to provide a shut-off valve that can simultaneously achieve high operating durability and economy with a simple structure.

  In order to solve the above problems, the present invention provides a stator having a coil, a rotor disposed inside the stator and excited and rotated by energization of the coil, a rotating shaft of the rotor, and the stator and rotor. A through-hole having a bottomed cylindrical partition wall that houses the rotor and maintains airtightness with the gas flow path, and a hole that is inserted into the opening side of the partition wall and through which the rotating shaft can pass. A lid formed with a recess on the outside, a radial / thrust common rolling bearing that is housed in the recess and supports loads in the radial direction and the thrust direction of the rotary shaft and rotor, and a linear motion mechanism disposed on the rotary shaft. A valve mechanism provided integrally, a flange having a sealing surface between the flow path and a flange that partitions the valve mechanism and the stator, and a flow path between the flange disposed on the outer periphery of the partition wall And stator And a sealing member for holding airtightness, the radial thrust shared rolling bearing to support the rotating shaft in the radial direction, in which a structure for supporting the holding means of the rotor in the thrust direction.

  As described above, by supporting the shaft center of the rotor with a metal partition, lid, and radial and thrust rolling bearings, the linear expansion coefficient is almost equal to that of the metallic rotating shaft, and locking due to temperature changes is possible. The minimum radial clearance can be set, the axial accuracy of the rotor on the partition open end side is increased, and stable operation performance can be realized with low power.

  The shut-off valve of the present invention supports a rotor shaft center with a metal partition wall, a lid, and a radial / thrust shared rolling bearing, so that the linear expansion coefficient is substantially equal to that of a metallic rotating shaft, and lock due to temperature change, etc. The minimum radial clearance can be set, the axial center accuracy of the rotor on the open end side of the partition wall can be increased, and stable operation performance can be realized with low power.

A shutoff valve according to claim 1 of the present invention is attached to a flow path having an inlet side and an outlet side of a fluid and a valve seat arranged on the outlet side, and controls the shutoff and flow of the fluid by opening and closing the valve seat. A shut-off valve,
A stator having a coil, a rotor disposed inside the stator and excited and rotated by energization of the coil, a rotating shaft of the rotor, and interposed between the stator and the rotor to house the rotor and gas A bottomed cylindrical partition wall that maintains airtightness with the flow path, a lid that is inserted in the opening side of the partition wall and has a hole through which the rotating shaft can pass, and a recess formed outside the through hole; A radial / thrust shared rolling bearing that is housed in a recess and supports loads in the radial direction and thrust direction of the rotary shaft and rotor, a valve mechanism provided integrally with a linear motion mechanism disposed on the rotary shaft, and the flow A flange having a sealing surface between the valve and the partition for partitioning the valve mechanism and the stator; and a seal member disposed on the outer periphery of the partition wall to maintain airtightness between the flow path and the stator between the flanges And be prepared The radial thrust shared rolling bearing to support the rotating shaft in the radial direction, in which a structure for supporting the holding means of the rotor in the thrust direction.

  As described above, by supporting the shaft center of the rotor with a metal partition, lid, and radial and thrust rolling bearings, the linear expansion coefficient is almost equal to that of the metallic rotating shaft, and locking due to temperature changes is possible. The minimum radial clearance can be set, the axial accuracy of the rotor on the partition open end side is increased, and stable operation performance can be realized with low power.

  Embodiments of the present invention will be described below with reference to the drawings.

Example 1
1 is a cross-sectional view of the shut-off valve of the first embodiment of the present invention in the open state, FIG. 2 is a perspective view of the flange and valve body of the shut-off valve of the first embodiment of the present invention, and FIG. 3 is the first embodiment of the present invention. Fig. 3 (a) shows the assembly of the radial and thrust rolling bearings on the partition wall, lid, rotor, partition wall open end side and bottom surface side of the shut-off valve, and Fig. 3 (b) shows the lid inserted. FIG. 4 is an assembly view showing a state in the middle, and FIG. 4 shows a partition wall, a lid, a rotor, a radial / thrust shared rolling bearing, a valve body, a spring, FIG. 4A is a cross-sectional view illustrating only a valve seat formed in a flow path, in which FIG. 4A is a cross-sectional view showing a relative positional relationship in a normal state including when a valve is opened, and FIG. 4B is closed. It is sectional drawing showing the relative positional relationship in a valve state.

  In FIG. 1, an exciting coil 61 in which a conducting wire is wound on a substantially bobbin-shaped coil bobbin, a first electromagnetic yoke 62 having a cylindrical portion on the outer periphery and a comb-shaped magnetic pole on the inner periphery, and the electromagnetic yoke Two sets of the second electromagnetic yoke 63 having a generally disc shape and having comb-like magnetic poles on the inner periphery, which are arranged so as to sandwich the exciting coil 61 between the second coil 62 and the second electromagnetic yoke 63, are mutually connected. The disk portions of the electromagnetic yoke 63 are arranged to face each other. Then, the fixing means 64 made of synthetic resin is integrally filled in all the gaps between the comb-shaped magnetic poles of the first electromagnetic yoke 62 and the second electromagnetic yoke 63, and at the same time, the fixing means 64 is connected to the exciting coil 61. The stator 65 is formed by filling all the gaps between the outer circumference of the first electromagnetic yoke 62 facing the outer circumference of the conducting wire and the inner side of the outer circumference cylindrical portion.

  The first electromagnetic yoke 62 and the second electromagnetic yoke 63 are made of a steel plate such as a low-carbon steel plate, an electromagnetic soft iron plate, or a silicon steel plate, and are subjected to rust prevention treatment such as galvanization, aluminum plating, chromic acid treatment film on the surface. It is preferable that the steel plate is made of an electromagnetic stainless steel plate such as a ferritic steel and is press-processed from a pre-plated steel plate such as a galvanized steel plate economically. In this embodiment, a galvanized steel sheet is pressed. The comb-shaped magnetic poles of the first electromagnetic yoke 62 and the second electromagnetic yoke 63 mesh with a predetermined gap, and the two sets of comb teeth are substantially the same as the other sets of comb teeth in the rotational direction. It is arranged to be located in the middle.

  A cylindrical portion 66a along the magnetic pole is formed inside the stator 65, a closed bottom portion 66b is formed at one end, and an inner pan-like portion 66c is formed concentrically at the center of the bottom portion 66b. A partition wall 66 made of an austenitic stainless steel sheet drawn into a pan shape without any through hole is disposed.

  As the material of the partition wall 66, nonmagnetic stainless steel, copper alloy, aluminum alloy and the like can be selected. However, fuel gas which is a low molecular hydrocarbon, moisture contained in the gas, hydrogen sulfide, Highly economical because it can be molded by progressive press working with corrosion resistance that can maintain stable performance without deterioration even when exposed to the severe temperature changes in an organic environment such as active gas that is a purified impurity such as sulfur. For the reasons such as thin-wall workability that can realize the properties, it is optimal to draw austenitic stainless steel irons. What removed the refinement | miniaturization of the crystal grain is desirable.

  A permanent magnet 67 having a circular tube shape whose outer periphery is polarized and magnetized, a metal rotating shaft 69 which is disposed through the permanent magnet 67 and has a lead screw 68 formed at one end, a permanent magnet 67 and the rotating shaft 69 are provided. A rotor 71 is constituted by the holding member 70 to be fixed, and is disposed inside the partition wall 66 so that the outer peripheral portion of the permanent magnet 67 and the magnetic poles of the electromagnetic yokes 62 and 63 of the stator 65 face each other.

Since the inner side of the partition wall 66 is on the gas side, the material constituting the rotor 71 is required to have high corrosion resistance. For this reason, the permanent magnet 67 is desirably a ferrite sintered magnet having high resistance to moisture, and the rotating shaft 69 can be selected from nickel, chrome-plated brass and stainless steel. In view of the possibility that a trace amount of gas is contained, a stainless steel rod is particularly desirable, and the holding member 70 is a crystalline synthetic resin having higher oil resistance such as polybutylene terephthalate (PBT) than resistance to hydrocarbon compounds in the gas. Is desirable.

  The open end 66d of the partition wall 66 has an outer diameter substantially the same as that of the open end 66d, and has a hole 72a through which the rotation shaft 69 can pass and a recess 72b coaxial with the hole 72a and away from the partition wall 66 in the center. A drawn stainless steel steel lid 72 includes a rotor inside the partition wall 66 and a lead screw 68 protruding from a hole 72a and is press-fitted into an open end 66d.

  Since the lid 72 is also on the gas side, corrosion resistance is required, and nickel or chrome-plated brass or stainless steel can be selected, but the gas may contain a trace amount of corrosive gases such as hydrogen sulfide. Considering this, it is particularly desirable to be made of stainless steel, and at the same time, by forming by drawing, it can be formed by progressive pressing and high economic efficiency can be realized.

  The lid 72 is not necessarily made of a non-magnetic material, and even if a fine crack is generated due to stress corrosion, it does not lead to gas leakage, so solution heat treatment or the like is not essential. An austenitic stainless steel sheet that is not heat-treated can be selected.

Further, the press-fitting interference with the partition wall 66 needs to be a loose tightening so as not to apply excessive stress to the partition wall 66. The end of the rotating shaft 69 on the bottom surface side of the partition wall 66 is opposed to the inner pot-like portion 66c. The tip thin shaft portion 69a having a smaller diameter than that of the other is formed at the position where the other end is placed, and a plurality of metal balls 73 are rotatably mounted between the inner pot-like portion 66c and the tip thin shaft portion 69a. A radial / thrust shared rolling bearing 74 is formed.

  A groove 69b having a smaller diameter than the other is formed between the holding member 70 of the rotating shaft 69 and the lead screw 68 and in the portion facing the recess 72b of the lid 72, and a plurality of metals are formed between the groove 69b and the recess 72b. A radial ball and thrust ball bearing 76 is formed by rotatably mounting a ball 75 made of metal.

  As shown in FIG. 3, the inner diameter D3 of the inner pot-like portion 66c of the partition wall 66 and the recess 72b of the lid 72 are respectively the tip thin shaft portion 69a, the outer diameter D2 of the groove 69b and the sphere 73, and the outer diameter D0 of the sphere 75. The sphere 73 and the sphere 75 are set to have an average diameter of the inner pot-like portion 66c, the recess 72b inner diameter D3, the tip thin shaft portion 69a, and the groove 69b outer diameter D2, respectively. 73, more than the number divided by the diameter D0 of the sphere 75 is installed, so that the bearing 74 and the bearing 76 can support the radial position of the rotating shaft 69.

  Although not used in this embodiment, when a cage is provided on the sphere 73 and the sphere 75, the inner pot-like portion 66c can be used if the number of the sphere 73 and the sphere 75 is three or more. The average number of the inner diameter of the concave portion 72b, the distal thin shaft portion 69a, and the outer diameter of the groove 69b may not be greater than the number obtained by dividing the average diameter by the diameters of the sphere 73 and the sphere 75.

  The step R1 between the tip thin shaft portion 69a (outer diameter D2) and the other portion (outer diameter D1) of the rotating shaft 69, and the groove 69b (outer diameter D2) and the large diameter portion (outer side) on the holding member 70 side. The connecting radius R2 of the step with the diameter D1) is preferably about 102 to 106%, which is slightly larger than the radius D0 of the sphere 73 and the sphere 75, respectively. is not.

  In the above description, the thrust and radial common rolling bearings 74 and 76 have been described as having the same main dimensions such as the diameter, but this is not necessarily the case.

  This type of shut-off valve normally does not operate at all and must be operated in response to a shut-off signal generated for the first time at the end of its life, for example. Therefore, the material of the sphere 73 and the sphere 75 is optimally an austenitic stainless steel sphere such as SUS304 that has corrosion resistance even without oil supply.

  Between the groove 69b of the rotating shaft 69 and the holding means 70, the outer side protrudes in the direction of the groove 69b, is a cylindrical shape coaxial with the rotating shaft 69, and can hold the ball 75 when the rotating shaft 69 is arranged vertically. Temporary holding means 77 that does not come into contact with the ball 75 when is inserted is formed integrally with the holding means 70.

  Sealed in the open hole of the flow path 78 and has a hole through which the rotary shaft 69 can protrude, and as shown in FIG. 2, a protrusion 79a is integrally formed in the center hole toward the center. The stator 65 is fixed to the outside of the flow path 78 of the flange 79 by fastening the electromagnetic yoke 62 or the like, and a sealing member 80 such as a synthetic rubber O-ring is disposed between the flange 79 and the outer wall of the partition 66 open end 66d. The inside and outside of the flow path 78 are hermetically sealed.

  A self-lubricating synthetic resin valve seat holding member 82 disposed by screwing a lead nut 81 formed in the center hole with a lead screw 68 at the tip of the rotary shaft 69 on the flow path 78 side, and this valve A valve body 84 is configured with a valve seat 83 made of a flexible body such as synthetic rubber disposed on the seat holding member 82, and as shown in FIG. 2, the valve seat holding member 82 has an axial direction toward the flange 79 side. The slit 82a is formed in parallel with the projection 79a of the flange 79, and the slit 82a and the projection 79a constitute a rotation preventing means, and the lead screw 68 and the lead nut 81 constitute a screw feed mechanism. The screw feed mechanism and the rotation preventing means constitute a linear motion mechanism.

  The valve seat holding member 82 formed with the lead nut 81 can be selected from polyoxymethylene, synthetic resin to which a solid lubricant such as polytetrafluoroethylene, carbon graphite, and molybdenum disulfide is applied.

  A spring 85 is compressed between the valve body 84 and the flange 79 so as to urge the valve body 84 in the direction of the valve seat 86. At the same time, the urging force of the spring 85 is radial except when the valve is closed. -Applying pressure to the thrust common roller bearing 76 to improve the shaft center holding accuracy.

  When assembling the shut-off valve, as shown in FIG. 3A, the partition wall 66 is held with the center axis vertically and the open end 66d facing up, and a plurality of metal balls 73 are inserted inside the partition wall 66. Next, the rotor 71 is installed inside the partition wall 66, and then a plurality of other metal balls 75 are suspended on the temporary holding means 77.

  At this time, the sphere 75 is not in contact with the groove 69b, and its outer diameter D5 is larger than the groove 69b diameter D2 plus twice the diameter of the sphere 75 and the inner diameter D3 of the recess 72b of the lid 72.

  Next, as shown in FIG. 3B, the lid 72 is press-fitted into the open end 66 d of the partition wall 66 and inserted.

  At this time, the sphere 75 is regulated by the recess 72b and its outer diameter becomes the same D3 as the inner diameter of the recess 72b, contacts or approaches the groove 69b, and comes off from the temporary holding means 77. Never do.

  Thus, the built-up assembly process in which the partition wall 66, the sphere 73, the rotor 71, the sphere 75, and the lid 72 are sequentially inserted can be realized, and the assembly process is high and high economic efficiency can be realized.

  Next, the operation and action of the shutoff valve of the first embodiment will be described.

  When the usage state of the gas is not abnormal and the signals from the various sensors do not indicate danger, there is no energization from the control unit (not shown) of the microcomputer meter, and the rotor 71 is stationary due to the detent torque. The body 84 keeps the valve open state away from the valve seat 86, and gas can flow.

  At this time, the relative positional relationship of the rotor 71 with respect to the partition wall 66 is that the valve body 84 is urged toward the valve seat 86 by the spring 85, so that the valve is within the range of the thrust clearance as shown in FIG. 4B. As a result, the radial / thrust common rolling bearing 76 receives a thrust load, and at the same time, the urging force of the spring 85 acts as a pressurizing force. The axial center holding accuracy of the rolling bearing 76 is improved.

  When the usage state of the gas is abnormal or the signals from various sensors indicate danger, the control unit of the microcomputer meter applies a pulsed current having a phase difference to each conducting wire of the exciting coil 61, and the rotor 71 Is rotated forward (clockwise in FIG. 1 as viewed from the valve body 84 side). Since the protrusion 79a, which is a rotation prevention mechanism, is engaged with the slit 82a to restrict the rotation of the valve seat holding member 82, when the lead screw 68 rotates forward, the lead nut 81 moves toward the valve seat 86 and integrally The valve body 84 moves, abuts on the valve seat 86 formed in the flow path 78, and the extra pulse is stepped out, and the shut-off valve is closed.

  Thereafter, even when the control unit of the microcomputer meter stops energization, the rotor 71 is stationary by the detent torque, and the valve body 84 holds the valve closed state biased by the spring 85 to the valve seat 86.

  At this time, the relative positional relationship of the rotor 71 with respect to the partition wall 66 is within the range of the thrust clearance as shown in FIG. 4B because the valve element 84 is in contact with the valve seat 86 and the linear motion mechanism is sent. Therefore, the partition 66 is biased to the inner pan-like portion 66c side, that is, to the right side in FIG. The axial center holding accuracy of the radial / thrust common rolling bearing 74 is improved.

  When the controller of the microcomputer meter determines that the danger is released from the signals from the various sensors and can be restored, or when the gas user recovers the dangerous condition and operates the return switch provided on the meter or remote control panel, When a gas supplier or the like issues a remote return command by communication, a pulsed current having a phase difference is applied to each conducting wire of the exciting coil 61 to rotate the rotor 71 in the reverse direction (in FIG. 1, the valve element 84 side). Rotate counterclockwise as viewed from the top). Then, it is sent to the lead screw 68, and the valve body 84 moves to the flange 79 side, is detached from the valve seat 86, and this shut-off valve is opened.

  Thereafter, the valve body 84 moves to the flange 79 side until the valve seat holding member 82 comes into contact with the lid 72, and the extra pulse is stepped out so that the shut-off valve is fully opened.

  And even if the control part of the microcomputer meter stops energization, the rotor 71 is stationary due to the detent torque, and this shut-off valve keeps the valve open state.

  The relative positional relationship of the rotor 71 with respect to the partition wall 66 during the valve opening return operation is that the valve body 84 is urged toward the valve seat 86 by the spring 85, so that as shown in FIG. In this range, the valve seat 86 side, that is, the left side in FIG. 4A is biased. As a result, the radial / thrust common rolling bearing 76 receives a thrust load, and at the same time, the urging force of the spring 85 acts as a pressurizing force. The axial center holding accuracy of the radial / thrust common rolling bearing 76 is improved.

  Further, at the moment of valve opening when the valve body 84 is detached from the valve seat 86, a load due to fluid pressure such as gas is added to the urging force of the spring 85 to inhibit the movement of the valve body 84 in the valve opening direction. Although acting, the radial / thrust common rolling bearing 76 receives a thrust load, so that torque loss is small and it can be driven with small electric power.

  Now, a shut-off valve using this type of PM type stepping motor as a drive source is required to maintain the axis of the rotor and ensure coaxiality with the hermetic partition for stable operation performance and low power.

  Moreover, it is generally attached to a gas meter installed outdoors, and is exposed to severe temperature changes from temperatures exceeding 50 ° C under direct sunlight in summer to -30 ° C in severe winter season, and at the same time The parts on the side of the passage 78 have the above-mentioned severe temperature in an organic environment such as a fuel gas that is a low-molecular hydrocarbon and an active gas that is a purified impurity such as moisture, hydrogen sulfide, and sulfur dioxide contained in the gas. The atmosphere side is exposed to severe conditions such as a high temperature and high humidity environment close to the saturation humidity outdoors and condensation in the gas meter. Among them, high airtight reliability is required so that no gas leaks during the service period (generally 10 years) of the gas meter.

  That is, it is necessary to satisfy both the axial center holding accuracy of the rotor 71 and high hermetic reliability.

  The shut-off valve shown in FIG. 1 includes an inner pan-like portion 66c of a metal partition 66, a recess 72b formed on a metal plate lid 72 fitted coaxially to the open end of the partition 66, and a metal A tip thin shaft portion 69a and a small-diameter groove 69b formed on the rotary shaft 69, a plurality of metal balls 73 provided between the inner pot-like portion 66c and the tip thin shaft portion 69a, and a recess 72b. A plurality of metal balls 75 installed between the rotary shaft 69 and the groove 69b form radial and thrust rolling bearings 74 and 76, respectively, and hold the axis of the rotor 71. The linear expansion coefficient is almost equal, the possibility of locking due to temperature changes is low, the minimum radial clearance can be set, the axial accuracy of the left and right sides of the rotor 71 in FIG. 1 is increased, and stable operation performance with low power Can also realize the bearing Since there is no sliding contact part, wear powder is less likely to be generated, and even if wear powder is generated, it is difficult to be electrified and absorbed due to metal powder, and it is possible to achieve high operating durability that prevents the rolling bearing function from being degraded. Since the radial and thrust shared rolling bearings 74 and 76 having the structure are configured, high economic efficiency can be realized.

  In addition, since the partition wall 66 does not have a through hole and the inside and outside of the partition wall 66 can be sealed with a single seal member 80, high hermetic reliability with few failure parts can be realized.

  Further, since the axial center of the rotor 71 is completed when the partition wall 66 and the lid 72 are assembled by inserting the radial / thrust common rolling bearing 76, the stator 65 and the flange 79 are fixed with a relatively low accuracy such as caulking. The method can be adopted, and it is possible to prevent a decrease in material strength and difficulty in manufacturing conditions due to welding, and it is possible to realize high hermetic reliability and economic efficiency that does not lead to gas leakage even if it breaks down.

Further, since the lid 72 is made of a drawn stainless steel plate and the partition wall 66 is made of a drawn austenitic stainless steel plate, fuel gas that is a low-molecular hydrocarbon, moisture contained in the gas, sulfide Even if it is exposed to the above severe temperature changes in an organic environment such as active gas that is a purified impurity such as hydrogen and sulfur dioxide, it can maintain stable performance without deterioration and can be molded by progressive press processing, and it is highly economical. Can be realized.

  Further, since the outer protrusion protrudes in the direction of the groove 69b, the temporary holding means 77 that can hold the ball 75 when the rotating shaft 69 is vertically arranged and does not come into contact with the ball 75 when the lid 72 is inserted is provided. The assembly method can be an up-type assembly process, and the assembly process is excellent and high economic efficiency can be realized.

  As described above, according to the present invention, high airtight reliability that can withstand humidity stress, temperature stress, chemical stress, etc. in long-term use, and stable operation performance with low electric power due to high accuracy of the rotor shaft center retention. In addition, it is possible to provide a shut-off valve that can simultaneously achieve high operating durability and economy with a simple structure.

  1, 3, and 4, the radial / thrust common rolling bearings 74, 76 have been described as being arranged on both sides of the rotor. However, when the thrust load at the time of valve closing becomes a problem, the radial / thrust common rolling bearings If the thrust load during the valve opening operation becomes a problem, a radial / thrust common rolling bearing 76 may be provided, and the other may be constituted by a self-lubricating synthetic resin sliding bearing or the like.

  In addition, although the radial and thrust common rolling bearings 74 and 76 are illustrated as a total ball type in which as many balls 73 and 75 as possible are inserted, they can be configured by three or more balls. It is desirable to use a cage for heart retention.

  Further, although the sealing member 80 between the partition wall 66 and the flange 79 is illustrated as being compressed in the radial direction, it may be disposed by being compressed in the axial direction.

  Further, although the valve seat holding member 82 and the lead nut 81 have been described as being integrally formed, separate parts may be used. In this case, a spring for biasing repulsive force may be provided between the valve seat holding member 82 and the lead nut 81. desirable.

  Although the valve seat 83 is illustrated so as to embrace the valve seat holding member 82, the valve seat 83 may be fitted in the center, and the valve seat holding member may be formed with a central axis so that the valve seat is hermetically penetrated and another fixing member. You may conclude with. Further, although the linear motion mechanism is the lead screw 68 and the lead nut 81, a combination of a cylindrical cam, a worm and a rack may be used.

Sectional drawing of the valve opening state of the shutoff valve of Example 1 of this invention 1 is a perspective view of a flange and a valve body of a cutoff valve according to a first embodiment of the present invention. (A) Assembly diagram of the partition and rotor before the lid assembly of the shut-off valve according to the first embodiment of the present invention, and the radial / thrust common rolling bearing on the open end side and the bottom surface side of the partition (b) The shut-off valve according to the first embodiment of the present invention Assembly drawing of the radial and thrust rolling bearings on the bulkhead, lid, rotor, bulkhead open end side and bottom side in the middle of lid insertion (A) A radial / thrust shared rolling bearing and valve on the partition wall, the lid, the rotor, the partition wall open end side, and the bottom surface side, representing the relative positional relationship in the normal state including when the shutoff valve of the first embodiment of the present invention is opened. Sectional view showing only body, spring, and valve seat formed in flow path (b) Represents relative positional relationship in shut-off state of shutoff valve of embodiment 1 of the present invention, partition, lid, rotor, partition open Cross-sectional view showing only radial and thrust rolling bearings on the end side and bottom side, valve body, spring, and valve seat formed in the flow path Cross-sectional view of a conventional shut-off valve in the open state Sectional view of other conventional shut-off valves in the open state

Explanation of symbols

65 Stator 66 Partition 66c Inner pan-shaped part 68 Lead screw (linear motion mechanism, screw feed mechanism)
69 Rotating shaft 69a Tip thin shaft portion 69b Groove 71 Rotor 72 Lid 72a Hole 72b Recess 73, 75 Ball 74, 76 Radial / Thrust common rolling bearing 77 Temporary holding means 79 Flange 79a Protrusion (rotation preventing means)
80 Seal member 81 Lead nut (linear motion mechanism, screw feed mechanism)
82a slit (rotation prevention means)
84 Valve body (valve mechanism)

Claims (1)

A shut-off valve attached to a flow path having an inlet side and an outlet side of a fluid and having a valve seat disposed on the outlet side and controlling the shutoff and flow of the fluid by opening and closing the valve seat, and a stator having a coil; A rotor disposed inside the stator and excited and rotated by energization of the coil, a rotating shaft of the rotor, and an airtightness between the stator and the rotor and accommodating the rotor to accommodate the gas flow path A bottomed cylindrical partition wall, a lid that is inserted in the opening side of the partition wall and has a hole through which the rotary shaft can pass, and a recess formed outside the through hole; Seals between the radial and thrust rolling bearings that support the radial and thrust loads of the shaft and rotor, the valve mechanism provided integrally with the linear motion mechanism disposed on the rotating shaft, and the flow path And mounting the valve mechanism with a surface The radial thrust thrust rolling bearing includes a flange that partitions the stator, and a seal member that is disposed on an outer periphery of the partition wall and maintains airtightness between the flow path and the stator between the flange. A shutoff valve configured to support the rotor in the thrust direction while supporting the rotor in the radial direction.

Images