JP2017120104A - Electromagnetic valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic valve which achieves high accuracy of flow adjustment when a passage is opened or closed.SOLUTION: An electromagnetic valve 1 includes: a plunger 32 which receives an electromagnetic force and reciprocates in a cylindrical body 35; and a valve body 31 which is provided at an end part of the plunger 32 and is moved close to or away from a valve seat by reciprocation movement of the plunger 32. A seal part of the valve body 31 contacts with an annular seal part of the valve seat to close the electromagnetic valve 1. The valve body 31 and the plunger 32 are connected by a connection part so as to allow movement relative to each other. The seal part of the valve body 31 is guided by a guide member 27 in a linear manner relative to the annular seal part of the valve seat.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electromagnetic valve that opens and closes a flow path by bringing a valve element into and out of contact with a valve seat using electromagnetic force.

  In a pipe through which a fluid such as gas or liquid flows, the plunger is reciprocated using the magnetic force of the electromagnet, and the opening / closing control of the flow path is performed by bringing the valve body provided at the tip of the plunger into contact with and separating from the valve seat There is a solenoid valve. The solenoid valve is fixed to a flange of a mounting plate of a gas meter or the like with a screw or the like, and a coil is wound around a bobbin housed inside a yoke that becomes a magnetic pole of the coil. A fixed iron core and a permanent magnet are provided in the central portion of the coil, and a plunger that is a movable iron core is inserted into a guide pipe that is attached to the central shaft of the bobbin. A gap is provided between the plunger and the guide pipe to reduce contact and facilitate movement of the plunger, and the plunger reciprocates in the guide pipe under the magnetic force generated by current flowing through the coil. This enables high-speed and linear reciprocation, which is a feature of the electromagnetic valve, and is widely used in applications where the flow path opening / closing interval is short and the number of opening / closing operations is large.

  In addition, the solenoid valve can be used at extremely low temperatures, where the use of other actuators is restricted due to the use of magnetic force. Solenoid valves with improved airtightness have been developed. For such a solenoid valve, for example, a technique disclosed in Patent Document 1 is employed. According to Patent Document 1, a bidirectional shut-off valve (solenoid valve) has a pilot pin with a valve element inserted at the tip of a plunger so as to be swingable, and a rubber valve seat constituting the valve element has a valve seat. The opening and closing control of the flow path is performed by making contact with and separating from. In addition, since the pilot pin that supports the valve body is swingably attached to the plunger, the angle of the valve body with respect to the valve seat can be adjusted, and the valve body is always at an angle parallel to the valve seat. The airtightness at the time of valve closing is improved by making it the pressed state.

JP-A-10-122411 (page 3, FIG. 1)

  However, in Patent Document 1, the pilot pin that supports the valve body is swingably attached to the plunger, and depending on the angle of entry of the valve body with respect to the valve seat, a part of the valve body is attached to the valve seat. Since the annular seal portion of the valve seat is closed by the seal portion of the valve body when the pilot pin is swung after contact with one side, the seal portion of the valve body and the annular seal portion of the valve seat It takes time to completely seal the flow rate, and there is a problem that the accuracy of flow rate adjustment at the time of opening and closing the flow path is lowered.

  The present invention has been made paying attention to such problems, and an object thereof is to provide an electromagnetic valve with high accuracy of flow rate adjustment when the flow path is opened and closed.

In order to solve the above problems, the solenoid valve of the present invention is:
A plunger that reciprocates in a cylindrical body under electromagnetic force, and a valve body that is provided at an end of the plunger and contacts and separates from a valve seat by the reciprocating movement of the plunger,
An electromagnetic valve that is closed when the seal portion of the valve body contacts the annular seal portion of the valve seat;
The valve body and the plunger are connected to each other by a connecting portion while allowing relative movement,
The seal portion of the valve body is guided linearly with respect to the annular seal portion of the valve seat by a guide member.
According to this feature, the plunger can maintain a low resistance reciprocating motion within the cylindrical body, while the guiding member ensures the linear motion of the valve body with respect to the annular seal portion of the valve seat in the on-off valve direction. In addition, the flow rate can be stably adjusted from the opening to the closing while maintaining high speed, and the accuracy of the flow adjustment when the flow path is opened and closed can be improved.

The connecting portion includes tilting permission means for allowing tilting of at least the valve body and the plunger.
According to this feature, since the valve body is connected to the plunger so as to be tiltable, regardless of the inclination of the plunger that occurs in the cylindrical body with respect to the reciprocating direction, the guide member prevents the valve body from being annularly sealed. The seal part of the valve body can be correctly guided.

The connecting portion is characterized by having horizontal movement allowing means for allowing movement of at least the valve body and the plunger in the horizontal direction.
According to this feature, since the valve body is connected to the plunger so as to be movable in the horizontal direction, the annular seal portion of the valve seat is guided by the guide member regardless of the movement of the plunger in the cylindrical body in the horizontal direction. In contrast, the seal portion of the valve body can be correctly guided.

The connecting portion includes at least tilting permission means that allows tilting of the valve body and the plunger, and horizontal movement permission means that allows movement in the horizontal direction.
According to this feature, the degree of freedom of movement of the valve body in the three-dimensional direction with respect to the plunger is improved, and the seal portion of the valve body can be correctly guided with respect to the annular seal portion of the valve seat by the guide member.

A cylindrical concave portion is formed on the plunger side of the connecting portion, and the concave spherical portion formed at one end portion of the valve body is accommodated in the concave portion, and the concave bottom surface and the head spherical shape described above. It is characterized by being held by a plate-like elastic body so that the tip of the part abuts.
According to this feature, the vertical movement of the valve body with respect to the plunger is regulated by the plate-like elastic body, and at the time of tilting each other, the plate-like elastic body is partially deformed and can be allowed to tilt smoothly.

The valve body includes a stem that is slidably guided by the guide member, and a mounting cone-shaped seal portion that is provided at the distal end of the stem and closes in contact with the annular seal portion of the valve seat. It is characterized by that.
According to this feature, when the mounting cone-shaped seal portion enters the annular seal portion of the valve seat, the seal portion of the valve body is aligned by the annular seal portion of the valve seat. A clearance between the guide member and the stem can be reduced.

It is sectional drawing which shows the structure of the solenoid valve in an Example. It is sectional drawing which shows the structure of a valve seat. It is a disassembled perspective view which shows the attachment structure of a plunger and a valve body. It is sectional drawing which shows the structure of the connection part of a plunger and a valve body. (A) is sectional drawing which shows the state of the valve body and valve seat at the time of valve opening, (b) is sectional drawing which shows the state of the valve body and valve seat at the time of valve closing. It is sectional drawing which shows the state of the connection part of a plunger and a valve body when a plunger inclines with respect to a reciprocation direction. It is sectional drawing which shows the state of the connection part of a plunger and a valve body when a plunger moves to a horizontal direction.

  EMBODIMENT OF THE INVENTION The form for implementing the solenoid valve which concerns on this invention is demonstrated below based on an Example.

  The solenoid valve according to the embodiment will be described with reference to FIGS. Hereinafter, the front side of the screen in FIG. 1 will be referred to as the front side (front side) of the solenoid valve, the back side will be referred to as the back side (rear side), and the description will be made with reference to the vertical and horizontal directions when viewed from the front side.

  The electromagnetic valve 1 of the present embodiment is provided, for example, for performing opening / closing control of a flow path through which a refrigerant (for example, liquid helium) flows in and out in a refrigeration cycle used in medical equipment such as MRI, a refrigerator, and the like. The electromagnetic valve 1 in the present embodiment will be described as a normally closed type.

  As shown in FIG. 1, the electromagnetic valve 1 includes a base member 2 having a refrigerant inflow passage 21 and an outflow passage 22, and a valve that is attached to the base member 2 and changes the communication state of the inflow passage 21 and the outflow passage 22. The body unit 3 is mainly composed of.

  As shown in FIG. 1 and FIG. 2, the base member 2 is formed with a ridge portion 23 having a substantially annular shape in plan view at a position inside the upper surface 2 a on the outer edge side. Further, a substantially annular recess 24 in plan view that is slightly recessed from the upper surface 2a is formed inside the protrusion 23, and further, on the inner side of the recess 24 (the center of the base member 2). In addition, a cylindrical protrusion 25 protruding upward from the ridge 23 is formed. Further, on the upper surface of the ridge 23, a protruding portion 26 protruding upward is provided in an annular shape so as to be continuous in the circumferential direction.

  At the center of the ridge 23, there are a recess 27 (guide member) extending in the axial direction of the ridge 23 and a plurality of holes penetrating from the inner peripheral surface of the recess 27 obliquely upward to the upper surface of the protrusion 25. The through holes 28 (four in this embodiment) are formed radially. In addition, the inflow passage 21 described above extends in the coaxial direction in the recess 27. As will be described later, a valve seat 29 with which the valve element 31 comes into contact is provided at a communication portion between the recess 27 and the inflow passage 21 as described later. The valve seat 29 has the same central axis as the concave portion 27 and is formed in a tapered shape that expands in an annular shape toward the concave portion 27. Further, the above-described outflow passage 22 is drilled in the bottom surface of the predetermined portion in the circumferential direction of the concave strip portion 24 so as to communicate with the outside of the base member 2. The base member 2 is formed by drilling the inflow passage 21 and the outflow passage 22, the recess 27, the through hole 28, and the valve seat 29 in the stainless cast product as described above. Furthermore, since the concave portion 27 and the valve seat 29 are formed by drilling a hole penetrating in the vertical direction from the protrusion 25 to the inflow passage 21, the diameter of the hole is increased in accordance with the dimensions of each portion. The central axis of the recess 27 and the valve seat 29 can be easily aligned on the same axis.

  As shown in FIG. 1, the valve body unit 3 includes a valve body 31, a cylindrical plunger 32 to which the valve body 31 is attached below, drive means 33 that drives the plunger 32 in the vertical direction, and It is mainly comprised from the bottomed cylindrical cap 34 which coat | covers. Various members are accommodated in the cap 34 and unitized. More specifically, the cap 34 containing various members is fitted on the outer side of the convex portion 23 of the base member 2 on which the gasket 4 is disposed, and the mounting flange 34a of the cap 34 is tightened with a bolt or the like (not shown) to The body unit 3 and the base member 2 are connected. The valve body 31 is made of polyimide resin, has excellent cold resistance, and can maintain excellent physical properties even at extremely low temperatures where liquid helium (−269 ° C.) is used as a fluid.

  In a state where the valve body unit 3 and the base member 2 are connected, a ring-shaped gasket 4 is sandwiched between the valve body unit 3 and the base member 2, and the valve body unit 3 and the base member 2 are sandwiched. And are connected in a sealed manner. Further, a space S is formed between the valve body unit 3 and the base member 2 (inside the gasket 4), and this space S communicates with the inflow passage 21 and the outflow passage 22. Further, the vertical movement of the valve body 31 is guided by the inner peripheral surface of the recess 27. As a result, when the valve body unit 3 and the base member 2 are coupled, The central axis 31 is inserted into the recess 27 with the central axis of the valve seat 29 being collinear with the central axis.

  The driving means 33 includes a cylindrical body 35 having a U-shaped cross-section for housing the plunger 32, a coil 36 provided on the outer periphery of the cylindrical body 35, a base core 37 fixed to the cylindrical body 35, a cylinder A magnet 38 provided above the cylindrical body 35, and a spring 39 connected between the plunger 32 and the base core 37.

  On the lower end surface 35b of the flange portion 35a provided at the lower edge of the cylindrical body 35, a protruding portion 35c protruding downward is provided in an annular shape so as to be continuous in the circumferential direction. The protruding portion 35c and the protruding portion 26 of the base member 2 described above are provided at positions corresponding to the upper and lower sides. When the valve body unit 3 and the base member 2 are connected, the protruding portion Since a part of the gasket 4 is sandwiched between the protrusion 26 and the projection 35c, the sealing performance in the space S is improved.

  Next, the opening / closing operation of the valve body unit 3 will be described. When an open current is applied to the coil 36 of the drive means 33, the plunger 32 moves upward due to the magnetomotive force of the coil 36, and the valve body 31 attached below the plunger 32 moves away from the valve seat 29 to open. (See FIG. 5 (a)). The energization necessary for the attraction of the plunger 32 is instantaneous. After the plunger 32 is attracted to the valve opening position, the energization is stopped and the plunger 32 is attracted to the valve opening position by the magnetic force of the magnet 38. The state is maintained.

  Further, when a closing current in a direction different from that when the valve is opened is supplied to the coil 36, the plunger 32 moves downward by the magnetomotive force in the opposite direction of the coil 36, and the valve element 31 comes into contact with the valve seat 29. The valve is closed (see FIG. 5B). The energization necessary for returning the plunger 32 is instantaneous as in the case of suction. After the plunger 32 returns to the valve closing position, the energization is stopped and the plunger 32 and the base core 37 are connected. The plunger 32 is maintained in the closed position by the biasing force of the spring 39. In this way, the valve body unit 3 has a self-holding solenoid structure in which the plunger 32 can be reciprocated by instantaneous energization, and can be opened and closed with power saving.

  As shown in the enlarged portion of FIG. 1, a gap L <b> 1 having a predetermined dimension is formed between the outer peripheral surface of the plunger 32 and the inner peripheral surface of the cylindrical body 35. Thereby, since the outer peripheral surface of the plunger 32 and the inner peripheral surface of the cylindrical body 35 are difficult to contact, the plunger 32 can move relative to the cylindrical body 35.

  As shown in FIG. 3 and FIG. 4, the valve body 31 is formed on the trunk 31 a (stem), the tip 31 b provided at the lower end of the trunk 31 a, and the upper end of the trunk 31 a. And a provided head portion 31c (mounting spherical portion). The body portion 31 a is guided by the inner peripheral surface of the concave portion 27 by sliding the outer peripheral surface thereof with respect to the inner peripheral surface of the concave portion 27 of the base member 2. Yes. The tip 31b has a smaller diameter than the body 31a, and the tip is a tapered surface 31d that gradually decreases in diameter downward. The head portion 31c has a larger diameter than the body portion 31a, and the upper end portion has a substantially hemispherical shape.

  The taper angle of the taper surface 31d of the valve body 31 is slightly smaller than the taper angle of the valve seat 29, and the valve surface 31 is closed when the taper surface 31d of the valve body 31 contacts the valve seat 29 in an annular shape. . For this reason, the contact load of a seal part becomes small, and even if the thrust of plunger 32 is small, the airtightness at the time of valve closing by valve body 31 can be improved. In addition, the seal part of the valve body 31 described below and the annular seal part of the valve seat 29 are parts where the tapered surface 31d of the valve body 31 and the valve seat 29 come into contact with each other when the valve is closed (FIG. 5 (b)). Furthermore, the shape of the annular seal portion of the valve seat 29 may be circular or polygonal.

  Further, the upper end portion of the head portion 31 c of the valve body 31 that faces the surface facing the plunger 32 has a substantially hemispherical shape so that the valve body 31 can be smoothly tilted with respect to the plunger 32.

  The plunger 32 is provided with an annular protrusion 32b that protrudes downward from a position inside the lower surface 32a on the outer edge side, and a concave portion 32c that is recessed upward is provided at the center of the lower surface 32a. Yes. On the inner peripheral surface of the annular protrusion 32b, a step part 32d and a recessed groove part 32e are formed over the entire periphery of the annular protrusion 32b.

  Next, the connection aspect of the valve body 31 and the plunger 32 is demonstrated. As shown in FIGS. 3 and 4, the valve body 31 is attached below the plunger 32 using an O-ring 5 (plate-like elastic body, tilting permitting means) and a C-ring 6. Specifically, the head portion 31c of the valve body 31 is inserted into the concave portion 32c. The concave portion 32c has a larger diameter than the head portion 31c, and the upper bottom surface thereof is formed into a flat surface. When the head portion 31c is inserted into the concave portion 32c, the outer peripheral surface of the head portion 31c. And a space L2 (horizontal movement allowing means) is formed between the inner peripheral surface of the concave portion 32c with a predetermined dimension.

  Further, the O-ring 5 is loosely fitted to the step portion 32d so as to be movable in the horizontal direction. The O-ring 5 is formed of hard rubber or the like, and the diameter of the through portion 5a provided in the center of the O-ring 5 is slightly larger than the body 31a of the valve body 31, and the head portion 31c. The diameter is smaller than. In a state where the O-ring 5 is disposed in the annular protrusion 32b, the body 31a of the valve body 31 is inserted into the through portion 5a provided in the center of the O-ring 5.

  Further, a C-ring 6 formed of stainless steel or the like and having elasticity is fitted into the concave groove portion 32e. When the C-ring 6 is fitted in the recessed groove portion 32e, the O-ring 5 is sandwiched from above and below by the C-ring 6 and the lower surface 32a of the plunger 32, and the O-ring 5 is prevented from being detached from the plunger 32. Has been. The C ring 6 has a larger diameter than the concave groove portion 32e. The C ring 6 is inserted into the concave groove portion 32e in a state where the diameter of the C ring 6 is reduced, and after the insertion into the concave groove portion 32e, the C ring 6 The state of being fitted into the recessed groove portion 32e is maintained by the elastic restoring force.

  Since the valve body 31 is attached below the plunger 32 as described above, the head portion 31 c is locked to the O-ring 5 and the valve body 31 is prevented from being detached from the plunger 32. When the valve body 31 is attached below the plunger 32, a gap L2 is formed between the substantially hemispherical outer peripheral surface of the head portion 31c and the inner peripheral surface of the concave portion 32c. Therefore, the valve body 31 can be relatively moved in a direction (horizontal direction) perpendicular to the reciprocating direction of the plunger 32. The O-ring 5 is an elastic body formed of a hard rubber or the like in a plate shape, and has a slight elasticity. Therefore, the O-ring 5 has a head 31c inserted into the concave portion 32c and the bottom surface and the head of the concave portion 32c. By holding by the O-ring 5 so that the tip of the portion 31c comes into contact with the plunger 32, the vertical movement of the valve body 31 with respect to the plunger 32 is restricted by the O-ring 5, and a part of the O-ring 5 is tilted with respect to each other. It is deformed and can tilt smoothly.

  As shown in FIG. 4, the connecting portion between the valve body 31 and the plunger 32 is formed by a head portion 31 c of the valve body 31, a concave portion 32 c of the plunger 32, and an O-ring 5. The degree of freedom of movement of the valve element 31 relative to 32 in the three-dimensional direction can be improved.

  As described above, in the electromagnetic valve 1 according to the present embodiment, the seal portion of the valve body 31 is guided linearly with respect to the annular seal portion of the valve seat 29 by the concave portion 27. While the plunger 32 maintains the low resistance reciprocating motion, the concave portion 27 ensures the linear motion of the valve body 31 in the direction of the opening / closing valve with respect to the annular seal portion of the valve seat 29, so that high speed performance is maintained. Stable flow rate adjustment can be performed from valve opening to valve closing, and the accuracy of flow rate adjustment when the flow path is opened and closed can be increased.

  The body 31 a of the valve body 31 has an outer peripheral surface slidably in contact with the inner peripheral surface of the recess 27, and the tapered surface 31 d at the tip of the valve body 31 contacts the annular seal portion of the valve seat 29 to close the valve. Therefore, when the mounting cone-shaped seal portion enters the annular seal portion of the valve seat 29, the sealing portion of the valve body 31 is caused by the annular seal portion of the valve seat 29. Since alignment is performed, a slight clearance between the recess 27 and the body 31a can be secured, and sliding resistance between the recess 27 and the body 31a can be reduced.

  According to this, when the plunger 32 moves relative to the cylindrical body 35 in the opening / closing operation of the valve body unit 3, it is formed between the outer peripheral surface of the plunger 32 and the inner peripheral surface of the cylindrical body 35 described above. The valve element 31 is movable relative to the inclination (see FIG. 6) and the horizontal movement (see FIG. 7) of the plunger 32 due to the distance L1. Since the seal portion 31 is smoothly guided linearly with respect to the annular seal portion of the valve seat 29 by the concave portion 27, the flow rate can be stably adjusted from opening to closing while maintaining high speed, The accuracy of flow rate adjustment when the flow path is opened and closed can be increased.

  5 to 7, the valve element 31 is pivotally supported so as to be relatively movable with respect to the plunger 32. However, the body 31a of the valve element 31 always has the concave portion 27 when the valve is opened and closed. Since the movement of the valve body 31 with respect to the valve seat 29 other than the opening / closing valve direction is restricted, the inflow passage 21 and the outflow passage 22 pass through the recess 27 and the space S. The valve body 31 does not move under the influence of the fluid to be operated, and the on-off valve operation can be performed while the valve body 31 is always stabilized. Can be increased.

  In the present embodiment, the valve body 31 is restricted in vertical movement by the O-ring 5 in which the head portion 31c is inserted into the concave portion 32c of the plunger 32, and the O-ring 5 is partially deformed smoothly when tilting each other. Although described as an aspect in which tilting is allowed, the present invention is not limited to this. By providing a clearance between the head portion 31c of the valve body 31 and the concave portion 32c of the plunger 32, tilting can be allowed. May be.

  In the present embodiment, the body 31a of the valve body 31 is slidably brought into contact with the recess 27 to guide the seal portion of the valve body 31 linearly with respect to the annular seal portion of the valve seat 29. However, the guide member may be freely configured as long as the seal portion of the valve body 31 can be linearly guided with respect to the annular seal portion of the valve seat 29. For example, a needle-type valve body A mode in which the tip is guided by the edge of the valve hole may be employed.

  Moreover, although the valve body 31 in a present Example demonstrated as an aspect in which the upper end part of the head 31c of the valve body 31 which hits the opposing surface with the plunger 32 became a substantially hemispherical shape, it is not restricted to this, The facing surface of the concave portion 32c to the head portion 31c of the valve body 31 may be substantially hemispherical, or both the facing surfaces of the valve body 31 and the plunger 32 may be substantially hemispherical.

  Moreover, although the valve body 31 in a present Example demonstrated as a mode closed by being inserted with respect to the valve seat 29, it is not restricted to this, The mode of valve closing of a valve body and a valve seat is free. For example, the disc-shaped valve element may be closed by being crimped so as to cover the valve seat.

  Although the embodiments of the present invention have been described with reference to the drawings, the specific configuration is not limited to these embodiments, and modifications and additions within the scope of the present invention are included in the present invention. It is.

  For example, in the above-described embodiment, the valve body 31 is locked below the plunger 32 by the O-ring 5 formed of elastic rubber or the like, but any plate-like elastic body that can lock the valve body 31 is used. Any shape may be used, and the material may be formed of a metal such as stainless steel.

DESCRIPTION OF SYMBOLS 1 Electromagnetic valve 2 Base member 3 Valve body unit 4 Gasket 5 O-ring (plate-like elastic body)
6 C-ring 21 Inflow passage 22 Outflow passage 27 Recessed portion (guide member)
28 Through-hole 29 Valve seat 31 Valve body 31a Body (stem)
31b Tip portion 31c Head (mounting spherical portion)
31d Tapered surface 32 Plunger 33 Driving means 34 Cap 35 Cylindrical body 36 Coil 37 Base core 38 Magnet 39 Spring

Claims (6)

A plunger that reciprocates in a cylindrical body under electromagnetic force, and a valve body that is provided at an end of the plunger and contacts and separates from a valve seat by the reciprocating movement of the plunger,
An electromagnetic valve that is closed when the seal portion of the valve body contacts the annular seal portion of the valve seat;
The valve body and the plunger are connected to each other by a connecting portion while allowing relative movement,
The solenoid valve according to claim 1, wherein the seal portion of the valve body is guided linearly with respect to the annular seal portion of the valve seat by a guide member.   The electromagnetic valve according to claim 1, wherein the connecting portion includes a tilt permission unit that allows at least the valve body and the plunger to tilt.   The electromagnetic valve according to claim 1, wherein the connecting portion includes horizontal movement allowing means for allowing movement of at least the valve body and the plunger in a horizontal direction.   2. The electromagnetic according to claim 1, wherein the connecting portion includes at least tilting permission means that allows tilting of the valve body and the plunger, and horizontal movement permission means that allows movement in a horizontal direction. valve.   A cylindrical concave portion is formed on the plunger side of the connecting portion, and the concave spherical portion formed at one end portion of the valve body is accommodated in the concave portion, and the concave bottom surface and the head spherical shape described above. The electromagnetic valve according to any one of claims 1 to 4, wherein the electromagnetic valve is held by a plate-like elastic body so as to abut the tip of the portion.   The valve body includes a stem that is slidably guided by the guide member, and a mounting cone-shaped seal portion that is provided at the distal end of the stem and closes in contact with the annular seal portion of the valve seat. The electromagnetic valve according to any one of claims 1 to 5, wherein:

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