JP5765142B2 - Differential pressure control valve and variable capacity compressor - Google Patents

Description

  The present invention relates to a differential pressure control valve and a variable displacement compressor.

  A conventional differential pressure control valve is disclosed in FIGS. These differential pressure control valves are arranged on a flow path for flowing fluid from the upstream side to the downstream side. Each differential pressure control valve includes a valve seat, a valve body, and a guide member.

  A valve hole through which fluid passes is formed in the valve seat. The valve seat is made of a magnetic material or a permanent magnet. The valve seat has a valve seat surface around the valve hole.

  The valve body is located downstream of the valve seat. The guide member is fixed to the valve seat and guides the valve body. The valve body opens and closes the valve hole by being seated or separated from the valve seat according to the pressure difference between the upstream side and the downstream side. The valve body disclosed in FIGS. 1 to 8 of the cited document 1 is made of a permanent magnet if the valve seat is a magnetic material, and made of a magnetic material if the valve seat is a permanent magnet. The valve body is formed with a valve body seating surface that sits on or separates from the valve seating surface. The valve body disclosed in FIGS. 9 to 11 of the cited document 1 is made of a permanent magnet or a magnetic material, and is made of a valve body body on which a valve body seating surface is formed and a resin that wraps the valve body body.

  In these differential pressure control valves, when the valve body is seated on the valve seat by the magnetic force acting between the permanent magnet and the magnetic material, the valve seat surface and the valve body seat surface come into contact with each other to close the valve hole. It is possible to prevent the back flow of the fluid. Further, in these differential pressure control valves, when the valve body is separated from the valve seat against the magnetic force, the valve seat surface and the valve body seat surface are separated, the valve hole is opened, and the fluid flows from upstream to downstream. It flows toward. During these periods, the valve body is biased toward the valve seat by magnetic force. The magnetic force acting between the permanent magnet and the magnetic material acts as an attractive force if the valve element is separated from the valve seat, and acts as an attractive force if the valve element is seated on the valve seat.

  Here, when comparing a general differential pressure control valve that urges the valve body to the valve seat only with a spring, and these differential pressure control valves, the urging force of the spring increases as the valve body moves away from the valve seat. On the other hand, the attraction force by the permanent magnet becomes weaker as the valve body moves away from the valve seat. For this reason, in these differential pressure control valves, the valve body is easily separated from the valve seat when the valve hole is opened, as compared with a general differential pressure control valve. For this reason, this differential pressure control valve can reliably open the valve hole even if the pressure difference is small, and can reduce pressure loss when fluid flows from the upstream side to the downstream side through the valve hole.

JP 2000-55223 A

  However, in the differential pressure control valve proposed in FIGS. 9 to 11 of Patent Document 1, the permanent magnet attracts foreign substances made of a magnetic material that can be contained in the fluid, and is interposed between the valve seat surface and the valve body seat surface. There is a risk that the foreign matter is adsorbed and bitten. In this case, a gap is formed between the valve seat surface and the valve body seat surface, and the valve hole cannot be reliably closed. For this reason, in the compressor which employ | adopted these differential pressure | voltage control valves as a non-return valve, the backflow of a fluid cannot be prevented reliably.

  The present invention has been made in view of the above-described conventional situation, and an object to be solved is to provide a differential pressure control valve that can reduce pressure loss and can reliably close a valve hole. Further, the present invention has a problem to be solved in a variable displacement compressor including a differential pressure control valve that can reduce pressure loss and reliably prevent fluid backflow.

The differential pressure control valve of the present invention is a valve seat in which a valve hole through which a fluid passes is formed, and is located on the downstream side of the valve seat, and the valve seat according to a pressure difference between the upstream side and the downstream side. In a differential pressure control valve comprising a valve body that opens and closes the valve hole by seating or separating from
The valve seat is made of a magnetic material, and has a valve seat body in which a valve seat surface is formed around the valve hole,
The valve body is made of a magnetic material, and has a valve body main body formed with a valve body seating surface that is seated or separated from the valve seating surface,
The valve seat is provided with a permanent magnet that urges the valve seat body and the valve body body so as to approach each other by an attractive force at a position recessed from the valve seat surface ,
In the vicinity of the valve seat surface, a foreign object storage part is provided that is disposed in a notch formed in the valve seat surface and can store a foreign material made of a magnetic material,
The valve body main body is formed in a convex shape with the tip being the valve body seat surface, and the notch is formed on the outer periphery.
The permanent magnet, it said the higher of Turkey than the magnetic flux density in the magnetic flux density is the dust containing portion of the time of sitting in the dust containing portion during the separating.

  Since the differential pressure control valve of the present invention employs a permanent magnet that urges the valve seat and the valve body so as to approach each other by an attractive force, the attractive force of the permanent magnet increases as the valve body moves away from the valve seat. As compared with a general differential pressure control valve, the valve body is likely to be separated from the valve seat when the valve hole is opened. For this reason, this differential pressure control valve can reliably open the valve hole even if the pressure difference is small, and can reduce pressure loss when fluid flows from the upstream side to the downstream side through the valve hole.

Further, the permanent magnet acts on the valve seat surface and the valve body seat surface with a magnetic flux density that allows the valve seat and the valve body to be seated when the permanent magnet is seated. For this reason, the valve seat surface and the valve body seat surface can be contacted at the time of seating. And the foreign material accommodating part is provided in the vicinity of the valve-seat seat surface . Further, the permanent magnet has a magnetic flux density in the foreign matter container at the time of sitting higher than the magnetic flux density in the foreign matter container at the time of seating due to the position where the permanent magnet is arranged. For this reason, the foreign material which consists of a magnetic material which can be contained in the fluid is attracted | sucked by the foreign material accommodating part with a high magnetic flux density at the time of valve opening. For this reason, when the valve is closed, the foreign matter is hardly adsorbed between the valve seat surface and the valve seat surface, which are in contact with each other, and the foreign matter is not easily caught between the valve seat surface and the valve seat surface. For this reason, with this differential pressure control valve, it is difficult to create a gap between the valve seat surface and the valve body seat surface during seating, and the valve hole can be closed more reliably.

  Therefore, the differential pressure control valve of the present invention can reduce pressure loss and can reliably close the valve hole.

The valve seat has a valve seat body. The valve seat body is made of a magnetic material. Further, the valve seat body has a valve seat surface formed around the valve hole. The valve body has a valve body. The valve body is made of a magnetic material. Moreover, the valve body main body is formed with a valve body seating surface that sits on or separates from the valve seating surface. As the magnetic material, high-carbon steel such as S45C, iron-based material such as chromium molybdenum steel such as SCM435 and SCM440, and martensitic stainless steel having magnetism can be employed . The valve body may be the valve body itself. The valve seat body or the valve body body may be formed as a valve seat or a valve body by being encased in resin for slidability or the like. Dust containing portion, Ru is formed on the valve seat.

Permanent magnets, so as to be higher than the magnetic flux density magnetic flux density at the valve seat seating surface and the valve body seating surface when the separating of the dust containing portion during the separating, have preferred to have been arranged. In this case, the foreign matter is easily sucked by the foreign matter storage portion when the valve is opened, and becomes difficult to bite between the valve seat surface and the valve body seat surface.

Dust containing section, that are located in a cutout formed in the valve seat seating surface. In this case, the foreign substance accommodating portion and the permanent magnet are located next to the valve seat surface and the valve body seat surface, and the effects of the present invention are likely to occur.

Permanent magnets, that are located in the recessed position with whether we stepped valve seat seating surface. In this case, the foreign matter container is secured by the step, and the effects of the present invention are likely to occur.

If dust containing portion on the distal end side of the permanent magnets are located, have preferred that the distal end surface of the permanent magnets are recessed. Thereby, a foreign material accommodation part can be enlarged and many foreign materials can be accommodated.

The distal end surface is not preferable that the step difference than people closer to the valve seat seating surface and the valve body seat is far from the valve seat seating surface and the valve body seating surface is large. In this case, it becomes more difficult for foreign matter to bite between the valve seat surface and the valve body seat surface. Such a front end surface may be formed in a taper shape or may be formed in a staircase shape.

Permanent magnet may be in the valve hole and the concentric annular. Then, the valve body tip formed in a convex shape is a valve body seat surface, Ru is outside circumferential notch formed. In this case, the valve seat body, Ru have a convex portion which is formed at the tip to be a valve seat seating surface cylindrical. If the valve seat body holds the permanent magnet, the weight of the valve body can be reduced, so that the operability of the valve body with respect to fluctuations in the pressure difference between the upstream side and the downstream side is improved.

Differential pressure control valve of the present invention is fixed to the valve seat, it has preferably be provided with a guide member made of a non-magnetic material for guiding the valve body. In this case, it becomes difficult for the magnetic flux lines of the permanent magnet to flow toward the guide member. For this reason, the magnetic flux density between the valve seat main body and the valve body main body is increased, so that the magnetic force acting between the valve seat main body and the valve body main body is increased, and the valve body easily moves toward the valve seat. And sits stably on the valve seat. For this reason, this differential pressure control valve can make a permanent magnet small, and size reduction is implement | achieved. As the nonmagnetic material, a resin, an aluminum-based material, or the like can be used.

  The differential pressure control valve of the present invention can include a spring that biases the valve body toward the valve seat. The attraction force of the permanent magnet becomes weaker as the valve body moves away from the valve seat. For this reason, if the valve body is urged toward the valve seat by the spring, the valve body can be reliably seated on the valve seat even if the valve body is largely separated from the valve seat. The spring is preferably made of a nonmagnetic material such as SUS316, resin, or FRP.

  The differential pressure control valve of the present invention may not include a spring that biases the valve body toward the valve seat. In this case, the valve body is urged toward the valve seat only by the attractive force acting between the permanent magnet and the magnetic material. For this reason, since this differential pressure control valve does not require a spring, the number of parts can be reduced and the assembling work can be simplified.

The permanent magnet may be provided on the valve seat the body using an adhesive. It may also be provided on the valve seat the body by press fitting or fitting the permanent magnet. If a permanent magnet is provided by press-fitting or fitting, the assembly work can be simplified as compared to providing the permanent magnet with an adhesive. In addition, when the permanent magnet is provided using an adhesive, the adhesive may deteriorate due to high temperature and the permanent magnet may be peeled off. On the other hand, if the permanent magnet is provided by press-fitting or fitting, the permanent magnet is affected by the high temperature. It is difficult to receive, and durability can be improved.

  As permanent magnets, (1) ferrite magnets such as barium ferrite magnets and strontium ferrite magnets, (2) metal magnets such as alnico magnets and rare earth magnets, and (3) bond magnets such as rubber magnets and plastic magnets, etc. Is possible. As rare earth magnets, neodymium magnets can be employed in addition to samarium-cobalt magnets such as 1-5 magnets and 1-17 magnets. As the rubber magnet, a ferrite rubber magnet or a neodymium rubber magnet can be employed. As the plastic magnet, a ferrite plastic magnet or a neodymium plastic magnet can be employed. A samarium-cobalt magnet has a slightly lower magnetic force than a neodymium magnet, but the temperature change rate (temperature decrease rate) of the magnetic force is smaller than that of a neodymium magnet, has excellent temperature characteristics, and is not easily rusted.

  The differential pressure control valve of the present invention can be embodied as a check valve that prevents back flow of fluid when seated, and controls a differential pressure by securing a certain clearance between the valve seat and the valve body when seated. It can also be embodied as

A variable displacement compressor according to the present invention includes a compression chamber and a discharge chamber, compresses the fluid sucked into the compression chamber, and can discharge the compressed fluid into the discharge chamber, and from the compression chamber to the discharge chamber. A variable capacity compressor configured to be able to change the discharge capacity of the fluid to be discharged,
Wherein said differential pressure control valve is disposed in the discharge passage communicating with the discharge chamber or the discharge chamber.

  In the variable displacement compressor of the present invention, the differential pressure control valve opens and closes the valve hole according to the pressure difference between the upstream side and the downstream side in the discharge chamber or the discharge passage. Specifically, when the fluid discharge capacity is minimized and the pressure difference between the upstream side and the downstream side becomes a predetermined value or less, the differential pressure control valve closes the valve hole. As a result, backflow of fluid from the discharge passage to the discharge chamber or from the discharge chamber to the compression chamber is prevented. That is, the differential pressure control valve functions as a check valve. On the other hand, when the fluid discharge capacity increases from the minimum and the pressure difference between the upstream side and the downstream side becomes larger than a predetermined value, the differential pressure control valve opens the valve hole. As a result, the fluid discharged from the compression chamber flows from the discharge chamber to the discharge passage.

  At this time, the variable capacity compressor can reduce pressure loss due to the operational effects of the differential pressure control valve of the present invention. In addition, the variable capacity compressor can reliably prevent the backflow of the fluid and the like due to the effect of the differential pressure control valve of the present invention.

  The differential pressure control valve of the present invention can reduce pressure loss and can reliably close the valve hole. In addition, the variable capacity compressor of the present invention can reduce pressure loss and reliably prevent fluid backflow and the like.

1 is a cross-sectional view of a variable displacement compressor that employs a differential pressure control valve of Example 1. FIG. 1 is a cross-sectional view of a differential pressure control valve of Example 1. FIG. 6 is a graph showing a relationship between a displacement amount of a valve element and an urging force acting on the valve element in the differential pressure control valve of Example 1. FIG. FIG. 6 is an explanatory diagram illustrating magnetic flux lines of a permanent magnet during separation from the differential pressure control valve according to the first embodiment. FIG. 6 is an explanatory diagram illustrating magnetic flux lines of a permanent magnet when seated according to the differential pressure control valve of the first embodiment. 4 is a cross-sectional view of a differential pressure control valve of Reference Example 1. FIG. It is explanatory drawing which shows the magnetic flux line of the permanent magnet at the time of separation concerning the differential pressure control valve of the reference example 1. FIG. It is explanatory drawing which shows the magnetic flux line of the permanent magnet at the time of seating in connection with the differential pressure control valve of the reference example 1 . 6 is a cross-sectional view of a differential pressure control valve of Reference Example 2. FIG. It is explanatory drawing which shows the magnetic flux line of the permanent magnet at the time of separation concerning the differential pressure control valve of the reference example 2 . It is explanatory drawing which shows the differential pressure control valve of the reference example 2 , and shows the magnetic flux line of the permanent magnet at the time of seating. 6 is a cross-sectional view of a differential pressure control valve of Reference Example 3. FIG. It is explanatory drawing which shows the differential pressure control valve of the reference example 3 , and shows the magnetic flux line of the permanent magnet at the time of separation. It is explanatory drawing which shows the differential pressure control valve of the reference example 3 , and shows the magnetic flux line of the permanent magnet at the time of seating. 10 is a cross-sectional view of a differential pressure control valve of Reference Example 4. FIG. It is sectional drawing of the differential pressure control valve of Example 2. FIG. FIG. 5 is an enlarged cross-sectional view of a main part of a differential pressure control valve of Example 2 . It is explanatory drawing which shows the magnetic flux line of the permanent magnet at the time of separation concerning the differential pressure control valve of Example 2. FIG. FIG. 6 is an explanatory diagram illustrating magnetic flux lines of a permanent magnet when seated according to the differential pressure control valve of the second embodiment. FIG. 6 is an enlarged cross-sectional view of a main part of a differential pressure control valve of Example 3 .

Examples 1 to 3 and Reference Examples 1 to 4 embodying the present invention will be described below with reference to the drawings.

Example 1
As shown in FIG. 1, the differential pressure control valve 100 according to the first embodiment is assembled to a variable displacement swash plate compressor (hereinafter simply referred to as “compressor”) and functions as a check valve. In this compressor, a plurality of cylinder bores 1a are formed concentrically in parallel with each other at equal angular intervals in a cylinder block 1. The cylinder block 1 is sandwiched between a front housing 3 positioned at the front and a rear housing 5 positioned at the rear, and is fastened in this state. A crank chamber 9 is formed inside the cylinder block 1 and the front housing 3. Here, the left side in FIG. 1 is the front, and the right side in FIG. 1 is the rear. The same applies to FIGS. 2 and 4 to 20.

  A shaft hole 3 a is formed in the front housing 3, and a shaft hole 1 b is formed in the cylinder block 1. A drive shaft 11 is rotatably supported in the shaft holes 3a and 1b via a shaft seal device 9a and bearing devices 9b and 9c. The front housing 3 is provided with a pulley 13 via a bearing device 3b. The pulley 13 is fixed to the drive shaft 11. A belt 13c driven by a vehicle engine or motor is wound around the pulley 13. An electromagnetic clutch may be provided instead of the pulley 13.

  A lug plate 15 is press-fitted into the drive shaft 11 in the crank chamber 9. Between the lug plate 15 and the front housing 3, bearing devices 9d and 9e are provided. A swash plate 17 is inserted through the drive shaft 11. Between the lug plate 15 and the swash plate 17, an inclination reduction spring 19 is provided around the drive shaft 11. Further, a circlip 11 a is fixed to the drive shaft 11 in the crank chamber 9. A return spring 21 is provided around the drive shaft 11 between the circlip 11 a and the swash plate 17. The lug plate 15 and the swash plate 17 are connected by a link mechanism 23 that supports the swash plate 17 so that the tilt angle can be changed.

  A piston 25 is accommodated in each cylinder bore 1a so as to be able to reciprocate. Between each piston 25 and the swash plate 17, shoes 27a and 27b which are paired in front and rear are provided. The swinging motion of the swash plate 17 is converted into the reciprocating motion of each piston 25 by the pair of shoes 27a and 27b.

  A valve unit 29 is provided between the cylinder block 1 and the rear housing 5. Each cylinder bore 1 a has a compression chamber 31 between the piston 25 and the valve unit 29. In the rear housing 5, there are formed a suction chamber 5a located on the radially inner side and an annular discharge chamber 5b located on the radially outer side. Refrigerant gas as a heat exchange fluid is supplied to the suction chamber 5a.

  The valve unit 29 sucks the refrigerant gas in the suction chamber 5a into the compression chamber 31 when the piston 25 is in the suction stroke, and compresses and discharges the refrigerant gas in the compression chamber 31 when the piston 25 is in the discharge process. Discharge into the chamber 5b.

  The crank chamber 9 and the suction chamber 5a are connected by an extraction passage 42. The crank chamber 9 and the discharge chamber 5b are connected by air supply passages 44 and 46. The rear housing 5 houses a capacity control valve 2 that communicates with the suction chamber 5a by the pressure detection passage 48 and communicates with the air supply passages 44 and 46.

  The capacity control valve 2 opens and closes the air supply passages 44 and 46 based on the flow rate differential pressure of the refrigerant gas detected by the pressure detection passage 48. Then, the high-pressure refrigerant gas in the discharge chamber 5b is supplied to the crank chamber 9 through the supply passages 44 and 46, and the pressure in the crank chamber 9 is adjusted to a desired value. As a result, the inclination angle of the swash plate 17 is changed to a desired discharge capacity.

  A discharge passage 50 is formed in the rear housing 5 so as to communicate with the discharge chamber 5 b and open on the rear surface of the rear housing 5. When the compressor is mounted on the vehicle air conditioner, the opening 5c on the rear surface side of the rear housing 5 in the discharge passage 50 is connected to a condenser (not shown).

  As shown in an enlarged view in FIG. 2, the discharge passage 50 includes a large-diameter hole 50 a that is recessed backward from the inner wall surface of the discharge chamber 5 b with an axis X 1 parallel to the front-rear direction as a central axis. It consists of a small-diameter hole 50b that allows the radial hole 50a and the opening 5c to communicate with each other. A differential pressure control valve 100 is disposed in the large-diameter hole 50a.

  The differential pressure control valve 100 includes a valve seat 110, a guide member 130, and a valve body 120. The differential pressure control valve 100 is assembled as a unit. The differential pressure control valve 100 is prevented from being removed by a circlip (not shown) or the like in a state where the valve seat 110 is abutted against the stepped portion 50c by being inserted into the large-diameter hole 50a from the discharge chamber 5b side. An O-ring 140 is provided on the outer peripheral surface of the valve seat 110. Thus, the differential pressure control valve 100 is fixed in the rear housing 5 with the discharge chamber 5b and the discharge passage 50 separated. The discharge chamber 5b is on the upstream side of the discharge passage 50, and the side opposite to the discharge chamber 5b across the valve seat 110 in the large-diameter hole 50a is the downstream side of the discharge passage 50.

  The valve seat 110 includes a base portion 113 having an axis X1 as a central axis, and a cylindrical portion 114 that is concentric with the base portion 113 and has a small diameter and is located rearward of the base portion 113. In this embodiment, the valve seat 110 is a valve seat body itself made of iron (S45C or the like) as a magnetic material.

  The base 113 and the cylindrical portion 114 are provided with a valve hole 111 having an axis X1 as a central axis. The valve hole 111 allows the discharge chamber 5 b to communicate with the downstream side of the discharge passage 50. The cylindrical portion 114 includes a small-diameter convex portion 115 positioned on the distal end side, and a guide member holding portion 116 that is positioned between the convex portion 115 and the base portion 113 and has a slightly larger diameter than the convex portion 115. The outer periphery of the convex 115 is a notch 115b. The tip of the convex portion 115 facing the rear is a valve seat surface 115a. The valve seat surface 115a is parallel to a plane orthogonal to the axis X1.

  The guide member 130 includes a cylindrical portion 133 having a cylindrical shape with the axis X1 as a central axis, and a disk portion 134 having a disk shape that blocks the rear end edge of the cylindrical portion 133. In this embodiment, the guide member 130 is made of a resin (nylon resin or the like) that is a nonmagnetic material. The guide member 130 is fixed to the valve seat 110 by fitting the front end edge 133a of the cylindrical portion 133 to the outer peripheral surface of the guide member holding portion 116 from the outside.

  In the middle of the cylindrical portion 133 in the front-rear direction, a plurality of windows 133b that allow the inside and the outside of the cylindrical portion 133 to communicate with each other are provided so as to be arranged on a circumference centered on the axis X1. Each window 133b is formed in a triangle whose apex is on the valve seat 110 side.

  The valve body 120 is accommodated in a space surrounded by the cylindrical portion 114 of the valve seat 110 and the guide member 130, and is located downstream of the discharge passage 50 with respect to the valve seat 110. The valve body 120 includes a cylindrical portion 121 having a cylindrical shape with the axis X1 as a central axis, and a disk portion 125 having a disk shape that closes the front end edge of the cylindrical portion 121. In this embodiment, the valve body 120 is a valve body itself made of iron (S45C or the like) as a magnetic material.

  A clearance is provided between the outer peripheral surface of the cylindrical portion 121 of the valve body 120 and the inner peripheral surface of the cylindrical portion 133 of the guide member 130 so that the valve body 120 can slide in the front-rear direction. Thereby, the valve body 120 is guided by the guide member 130 and can be displaced in the front-rear direction.

  The outer diameter of the disk part 125 of the valve body 120 is made substantially equal to the outer diameter of the convex part 115, and the outer peripheral area of the front end surface of the disk part 125 is a valve body seating surface 125a. The valve seat surface 125a is also parallel to a plane orthogonal to the axis X1. When the valve body 120 is displaced forward and the valve body seating surface 125a comes into contact with the valve seating surface 115a, the valve body 120 is seated on the valve seat 110 and the valve hole 111 is closed. At this time, the cylindrical portion 121 of the valve body 120 closes the window 133b. When the valve body 120 is displaced rearward from the state, the valve body 120 is separated from the valve seat 110 to open the valve hole 111. At this time, the cylindrical portion 121 opens the window 133b. Then, the valve body 120 is further displaced rearward, and the rear end of the cylindrical portion 121 is stopped against the disk portion 134 of the guide member 130, whereby the valve hole 111 is fully opened. At this time, the cylindrical portion 121 fully opens the window 133b.

  A permanent magnet 150 is fixed to the notch 115b of the valve seat 110 with an adhesive or the like. The permanent magnet 150 is disposed at a position recessed from the valve seat surface 115a with a step D. That is, the front end surface of the permanent magnet 150 on the valve seat surface 115a side is parallel to a plane orthogonal to the axis X1. Moreover, the front end surface of the permanent magnet 150 is located farther from the valve body seat surface 125a than the valve seat surface 115a, and does not contact the valve body seat surface 125a. The more the permanent magnet 150 is lowered from the valve seat surface 115a, the lower the magnetic flux density of the valve seat surface 115a when the valve is opened. For this reason, the space from the front end surface of the permanent magnet 150 to the valve seat surface 115a in the notch 115b is defined as the first foreign object storage portion 115c. The permanent magnet 150 is set according to the relationship between the attractive force and attractive force between the valve body 120 and the valve seat 110 and the magnetic flux density at the time of opening the valve.

  The permanent magnet 150 has an annular shape concentric with the valve hole 111 with the axis X1 as the central axis. In this embodiment, the permanent magnet 150 is a neodymium magnet. The permanent magnet 150 provided at this position urges the valve seat 110 and the valve body 120 to approach each other by an attractive force based on the magnetic force. On the outer periphery of the disk portion 125, a second foreign matter storage portion 125b is formed which is integrated with the first foreign matter storage portion 115c when the valve is closed. This differential pressure control valve does not include a spring that biases the valve body 120 toward the valve seat 110.

  FIG. 3 shows the relationship between the displacement amount of the valve body 120 and the urging force that urges the valve body 120 toward the valve seat 110 by solid lines S1 and S2. A solid line S <b> 1 indicates a relationship between the displacement amount of the valve body 120 and the magnetic force acting between the permanent magnet 150 and the valve seat 110. Here, the magnetic force acting between the permanent magnet 150 and the valve seat 110 is an attractive force when the displacement amount of the valve body 120 is zero, and is an attractive force when the displacement amount is larger than zero.

  On the other hand, a solid line S2 shows an example of a biasing force that biases the valve body toward the valve seat in a general differential pressure control valve that biases the valve body toward the valve seat only by the spring. In this example, a differential pressure control valve is assumed in which the permanent magnet 150 is removed from the differential pressure control valve 100 of this embodiment, and a spring with a strong biasing force is used instead of the spring 140.

  In the case of Example 1, as indicated by the solid line S1, when the valve hole 111 is closed, that is, when the displacement amount of the valve body 120 is 0, the attractive force acting between the permanent magnet 150 and the valve seat 110 is It is set so that the seating between the valve seat 110 and the valve body 120 can be maintained when the pressure difference between the discharge chamber 5b and the downstream side of the discharge passage 50 is a predetermined value ΔP or less. Further, as shown by a solid line S2, this adsorption force is set so that a spring in a general differential pressure control valve is the same as an urging force that urges the valve body 120 toward the valve seat 110 when the valve hole 111 is closed. Has been.

  On the other hand, in the case of a general differential pressure control valve, as shown by a solid line S2, when the valve hole 111 is opened, that is, when the displacement amount of the valve body 120 becomes larger than 0, the spring causes the valve body 120 to be displaced. The urging force that urges the power increases proportionally.

  On the other hand, in the case of Example 1, as indicated by the solid line S1, when the valve hole 111 is opened, that is, when the displacement amount of the valve body 120 is greater than 0, the gap between the permanent magnet 150 and the valve seat 110 is The suction force acting on the abruptly decreases.

  In the compressor configured as described above, in the vehicle air conditioner, the discharge chamber 5b is connected to the condenser via the discharge passage 50, the condenser is connected to the evaporator via the expansion valve, and the evaporator is Connected to the suction chamber 5a. When the drive shaft 11 is rotationally driven by an engine or the like, the refrigerant gas in the suction chamber 5a is compressed in the compression chamber 31 with a discharge capacity corresponding to the inclination angle of the swash plate 17, and discharged to the discharge chamber 5b.

  During this time, for example, the capacity control valve 2 operates in response to a change command of the air conditioning temperature by the passenger, a change in the rotational speed of the vehicle engine, or the like. When the high-pressure refrigerant gas in the discharge chamber 5b is supplied to the crank chamber 9 via the supply passages 44 and 46, the inclination angle of the swash plate 17 is reduced and the discharge capacity is reduced. Conversely, if it becomes difficult for the high-pressure refrigerant gas in the discharge chamber 5b to be supplied to the crank chamber 9 via the supply passages 44 and 46, the inclination angle of the swash plate 17 increases and the discharge capacity increases. Thus, in this compressor, the discharge capacity can be changed as appropriate.

  Here, the differential pressure control valve 100 operates as follows. When the inclination angle of the swash plate 17 is minimized and the discharge capacity of the refrigerant gas discharged from the discharge chamber 5b is minimized, the pressure difference between the discharge chamber 5b and the downstream side of the discharge passage 50 becomes a predetermined value ΔP or less. . Then, as shown in FIG. 2, the valve body 120 is urged toward the valve seat 110 by the attractive force acting between the permanent magnet 150 and the valve body 120, and is seated on the valve seat 110. Closes the valve hole 111. The state is maintained by the attractive force acting between the permanent magnet 150 and the valve body 120. As a result, the discharge passage 50 is closed, and the refrigerant circulation between the compressor, the condenser, the expansion valve, and the evaporator is stopped.

  On the other hand, when the inclination angle of the swash plate 17 increases from the minimum, the discharge capacity of the refrigerant gas discharged from the discharge chamber 5b also increases, and the pressure difference between the discharge chamber 5b and the downstream side of the discharge passage 50 becomes a predetermined value ΔP. Exceed. As a result, the attractive force acting between the permanent magnet 150 and the valve body 120 loses the pressure difference, and the valve body 120 cannot close the valve hole 111, and the valve body 120 is guided by the guide member 130 and the valve seat. Get away from 110. Then, as indicated by a solid line S1 in FIG. 3, the attractive force acting between the permanent magnet 150 and the valve body 120 is rapidly reduced, so that the valve body 120 is further pushed by the refrigerant gas passing through the valve hole 111. . For this reason, the valve body 120 is greatly separated from the valve seat 110, and the valve body 120 opens the window 133b. As a result, the discharge passage 50 is quickly switched to the fully open state, and refrigerant circulation is performed among the compressor, the condenser, the expansion valve, and the evaporator.

  Here, since the differential pressure control valve 100 according to the first embodiment employs a permanent magnet 150 that urges the valve seat 110 and the valve body 120 to approach each other by an attractive force, a solid line S1 in FIG. As shown by S2, the attraction force of the permanent magnet 150 becomes weaker as the valve body 120 moves away from the valve seat 110, and the valve body 120 is opened when the valve hole 111 is opened as compared with a general differential pressure control valve. It is easy to leave the seat 110. For this reason, the differential pressure control valve 100 can reliably open the valve hole 111 even when the pressure difference between the discharge chamber 5b and the downstream side of the discharge passage 50 is small, particularly when the flow rate is low, and the refrigerant gas flows into the discharge chamber 5b. Pressure loss at the time of flowing downstream from the discharge passage 50 through the valve hole 111 can be reduced.

  Further, in this differential pressure control valve, as shown in FIG. 4, the permanent magnet 150 has a valve seat 110 and a valve at the time of seating with respect to the valve seat surface 115a and the valve body seat surface 125a depending on the position of the permanent magnet 150. The magnetic flux density that can be seated with the body 120 acts. For this reason, the valve seat surface 115a and the valve body seat surface 125a can contact | abut at the time of seating. FIG. 5 shows a state where the valve hole 111 is closed and the differential pressure control valve is closed. In this state, even if foreign matter made of a magnetic material that can be contained in the refrigerant gas enters the vicinity of the valve seat seat surface 115a and the valve seat seat surface 125a, they are already in contact with each other. There is no risk of biting.

  And the 1st, 2nd foreign material accommodating part 115c, 125b is provided in the vicinity of the valve seat surface 115a. Also, as shown in FIGS. 4 and 5, the permanent magnet 150 changes the magnetic flux density in the first and second foreign matter storage portions 115 c and 125 b at the time of separation depending on the position of the permanent magnet 150, and the magnetic flux density A concentrated area occurs. For this reason, the magnetic flux density in the first and second foreign matter storage portions 115c and 125b at the time of separation shown in FIG. 4 is set higher than the magnetic flux density in the first and second foreign matter storage portions 115c and 125b at the time of sitting shown in FIG. ing. On the other hand, the magnetic flux densities on the valve seat surface 115a and the valve body seat surface 125a at the time of separation shown in FIG. 4 are lower than those on the seating shown in FIG. Moreover, the magnetic flux density in the 1st foreign material accommodating part 115c at the time of separation shown in FIG. 4 is higher than the magnetic flux density of the valve seat surface 115a and the valve body seat surface 125a at the time of separation shown in FIG. FIG. 4 shows a state where the valve hole 111 is opened and the differential pressure control valve is opened. In this state, since the distance between the valve body 120 and the valve seat 110 increases, the magnetic flux line from the permanent magnet 150 changes, and the magnetic flux line passes through the valve seat 110 closer to the valve body 120. For this reason, the area | region where a magnetic flux line concentrates between the permanent magnet 150 and the valve seat 110 generate | occur | produces, and a foreign material is attracted. The sucked foreign matter is accommodated in the first foreign matter accommodation portion 115c on the valve seat 110 side and the second foreign matter accommodation portion 125b on the valve body 120 side.

For this reason, when the valve is opened, foreign matter is attracted to the first foreign matter storage portion 115c that is provided in the vicinity of the valve body seating surface 125a of the valve body 120 provided with the permanent magnet 150, and the magnetic flux lines are concentrated and the magnetic flux density is high. Is done. The sucked foreign matter is accommodated in the first and second foreign matter accommodation portions 115c and 125b. Therefore, when the valve is closed, it is difficult for the foreign matter to be adsorbed between the valve seat surface 115a and the valve body seat surface 125a that come into contact, and the foreign matter is caught between the valve seat surface 115a and the valve body seat surface 125a. hard. For this reason, in this differential pressure control valve, it is hard to produce a clearance gap between the valve seat surface 115a and the valve body seat surface 125a at the time of seating, and the valve hole 111 can be closed more reliably.

  In this differential pressure control valve, since the valve seat 110 made of a magnetic material is magnetized by the permanent magnet 150, even if the valve body 120 is separated from the valve seat 110, the first and second foreign matter storage portions 115c and 125b Adsorbed by magnetic force.

  Therefore, this differential pressure control valve can reduce the pressure loss and can reliably close the valve hole 111. Further, the variable displacement compressor can reduce pressure loss and reliably prevent the backflow of the refrigerant gas due to the effect of the differential pressure control valve.

  Further, in this differential pressure control valve, since the valve seat 110 holds the permanent magnet 150, the weight of the valve body 120 is light, and the operability of the valve body 120 with respect to fluctuations in the pressure difference between the upstream side and the downstream side is improved. It has improved.

  Further, since the differential pressure control valve includes the guide member 130 made of a nonmagnetic material, the magnetic flux lines of the permanent magnet 150 are difficult to flow toward the guide member 130. For this reason, since the magnetic flux density between the valve seat 110 and the valve body 120 increases, the magnetic force acting between the valve seat 110 and the valve body 120 increases, and the valve body 120 moves toward the valve seat 110. It is easy to do and is seated stably on the valve seat 110. For this reason, this differential pressure control valve can make the permanent magnet 150 small, and the miniaturization is realized.

  Further, since the differential pressure control valve does not include a spring that biases the valve body 120 toward the valve seat 110, the number of parts is reduced and the assembling work is simplified.

  The valve body 120 and the valve seat 110 may not be entirely made of a magnetic material. Since it is only necessary to generate a magnetic flux concentration region between the permanent magnet 150 and the valve body 120 or the valve seat 110 to attract foreign matter, the valve body 120 and the valve seat 110 have at least portions disposed on the side surfaces of the permanent magnet 150. Any magnetic material may be used. Further, the valve seat surface 115a and the valve body seat surface 125a themselves may not be magnetic materials. The valve body 120 and the valve seat 110 may be formed of a magnetic material, and the valve seat surface 115a and the valve body seat surface 125a may be coated with a resin.

(Reference Example 1)
As shown in FIG. 6, the differential pressure control valve 200 of Reference Example 1 is disposed in the large-diameter hole 50 a of the discharge passage 50. The differential pressure control valve 200 includes a valve seat 210, a guide member 230, and a valve body 220.

  The valve seat 210 includes a base portion 213 having an axis X1 as a central axis, and a convex portion 214 that is concentric with the base portion 213 and has a small diameter, and is located rearward with respect to the base portion 213. A valve hole 211 having an axis X1 as a central axis is provided through the base 213 and the convex 214. The tip of the convex portion 214 facing the rear is a valve seat surface 214a.

  The guide member 230 includes a cylindrical portion 233 having a cylindrical shape with the axis X1 as a central axis, and a disk portion 234 having a disk shape that blocks the rear end edge of the cylindrical portion 233. The guide member 230 is fixed to the convex portion 214 of the valve seat 210.

  In the middle of the cylindrical portion 233 of the guide member 230 in the front-rear direction, a plurality of windows 233b that allow the inside and the outside of the cylindrical portion 233 to communicate with each other are provided so as to be arranged on a circumference centered on the axis X1.

  The valve body 220 is accommodated in a space surrounded by the convex portion 214 of the valve seat 210 and the guide member 230. The valve body 220 includes a cylindrical portion 221 having a cylindrical shape with the axis X1 as a central axis, and a disk portion 225 having a disk shape that closes the front end edge of the cylindrical portion 221.

  The outer peripheral area of the front end surface of the disc portion 225 of the valve body 220 is a valve body seating surface 225a. A notch 214d is formed in the inner periphery of the convex portion 214 of the valve seat 210, and a permanent magnet 250 is fixed in the notch 214d by press-fitting. The permanent magnet 250 has an annular shape concentric with the valve hole 211 with the axis X1 as the central axis. The permanent magnet 250 has a through hole 250 a having the same diameter as the valve hole 211.

  The permanent magnet 250 is disposed at a position recessed from the valve seat surface 214a with a step D. A space from the tip surface of the permanent magnet 250 to the valve seat surface 214a in the inner periphery of the convex portion 214 serves as a foreign matter storage portion 214c. Other configurations are the same as those of the first embodiment.

  In this differential pressure control valve, as shown in FIG. 8, the permanent magnet 250 has a predetermined magnetic flux that allows the valve seat 210 and the valve body 220 to be seated on the valve seat surface 214a and the valve body seat surface 225a. Acting density. For this reason, the valve seat surface 214a and the valve body seat surface 225a can be contacted at the time of seating.

  Even in a state where the valve body 220 is seated on the valve seat 210, the foreign matter storage portion 214 c exists behind the permanent magnet 250. FIG. 7 shows magnetic flux lines at the time of separation. At the time of separation, since the distance between the valve body 220 and the valve seat 210 is widened, the magnetic flux line from the permanent magnet 250 changes from when the valve is closed, and the magnetic flux line passes through the valve seat 210 closer to the valve body 220. For this reason, the area | region where a magnetic flux line concentrates between the permanent magnet 250 and the valve seat 210 generate | occur | produces, and a foreign material is attracted. The sucked foreign matter is accommodated in the foreign matter accommodation portion 214c. On the other hand, the magnetic flux density at the valve seat surface 214a and the valve body seat surface 225a at the time of sitting is lower than those at the time of sitting. Further, the magnetic flux density in the foreign matter container 214c during the separation is higher than the magnetic flux densities of the valve seat surface 214a and the valve body seat surface 225a during the separation. For this reason, the foreign matter is not attracted to the valve seat surface 214a and the valve body seat surface 225a, and is accommodated in the foreign matter accommodation portion 214c. In addition, since the foreign material storage part 214c is adjacent to the permanent magnet 250, the stored foreign material remains in the foreign material storage part 214c even when the valve body 220 is separated from the valve seat 210. Other functions and effects are the same as those of the first embodiment.

(Reference Example 2)
As shown in FIG. 9, the differential pressure control valve 300 of Reference Example 2 is disposed in the large diameter hole 50 a of the discharge passage 50. The differential pressure control valve 300 includes a valve seat 310, a guide member 330, and a valve body 320.

  The valve seat 310 includes a base portion 313 having an axis X1 as a central axis, and a cylindrical portion 314 which is concentric with the base portion 313 and has a small diameter and is located rearward of the base portion 313. The base portion 313 and the cylindrical portion 314 are provided with a valve hole 311 having an axis X1 as a central axis. The tip of the cylindrical portion 314 facing the rear is a valve seat surface 314a.

  The guide member 330 includes a cylindrical portion 333 having a cylindrical shape with the axis X1 as a central axis, and a disk portion 334 having a disk shape that closes the rear end edge of the cylindrical portion 333. The guide member 330 is fixed to the cylindrical portion 314 of the valve seat 310.

  In the middle of the cylindrical portion 333 of the guide member 330 in the front-rear direction, a plurality of windows 333 b that communicate between the inside and the outside of the cylindrical portion 333 are provided so as to be arranged on a circumference centered on the axis X1.

  The valve body 320 is accommodated in a space surrounded by the cylindrical portion 314 of the valve seat 310 and the guide member 330. The valve body 320 includes a convex portion 321 having a cylindrical shape with the axis X1 as a central axis. The front end surface of the convex portion 321 is a valve body seating surface 321a. A permanent magnet 350 is fixed to the inner periphery of the convex portion 321 by press-fitting. The permanent magnet 350 has a columnar shape that is concentric with the valve hole 311 with the axis X1 as the central axis.

  The permanent magnet 350 is disposed at a position recessed from the valve seat surface 321a with a step D. A space from the front end surface of the permanent magnet 350 to the valve body seat surface 321a in the inner periphery of the convex portion 321 serves as a foreign matter storage portion 321c. Other configurations are the same as those of the first embodiment.

  In this differential pressure control valve, as shown in FIG. 11, the permanent magnet 350 has a predetermined magnetic flux that allows the valve seat 310 and the valve body 320 to be seated with respect to the valve seat surface 314a and the valve body seat surface 321a. Acting density. For this reason, the valve seat surface 314a and the valve body seat surface 321a can be contacted at the time of seating.

  Even in a state in which the valve body 320 is seated on the valve seat 310, the foreign substance storage portion 321 c exists in front of the permanent magnet 350. FIG. 10 shows the magnetic flux lines at the time of separation. At the time of separation, the distance between the valve body 320 and the valve seat 310 increases, so that the magnetic flux line from the permanent magnet 350 changes from when the valve is closed, and the magnetic flux line passes through the valve body 320 closer to the valve seat 310. For this reason, the area | region where a magnetic flux line concentrates between the permanent magnet 350 and the valve body 320 generate | occur | produces, and a foreign material is attracted. The sucked foreign matter is accommodated in the foreign matter accommodation portion 321c. On the other hand, the magnetic flux densities on the valve seat surface 314a and the valve body seat surface 321a at the time of sitting are lower than those on the seating. In addition, the magnetic flux density in the foreign matter container 321c during the separation is higher than the magnetic flux densities of the valve seat surface 314a and the valve body seat surface 321a during the separation. For this reason, the foreign matter is not adsorbed on the valve seat surface 314a and the valve body seat surface 321a, but is accommodated in the foreign matter accommodation portion 321c. In addition, since the foreign material accommodating part 321c is also adjacent to the permanent magnet 350, even if the valve body 320 leaves | separates from the valve seat 310, the accommodated foreign material remains in the foreign material accommodating part 321c. Other functions and effects are the same as those of the first embodiment.

(Reference Example 3)
As shown in FIG. 12, the differential pressure control valve 400 of Reference Example 3 is disposed in the large-diameter hole 50 a of the discharge passage 50. The differential pressure control valve 400 includes a valve seat 410, a guide member 430, and a valve body 420.

  The valve seat 410 includes a base portion 413 having an axis X1 as a central axis, and a cylindrical portion 414 that is concentric and small in diameter with respect to the base portion 413 and is located rearward of the base portion 413. The base portion 413 and the cylindrical portion 414 are provided with a valve hole 411 having an axis X1 as a central axis. A front end facing the rear of the cylindrical portion 414 is a valve seat surface 414a.

  The guide member 430 includes a cylindrical portion 433 having a cylindrical shape with the axis X1 as a central axis, and a disk portion 434 having a disk shape that closes the rear end edge of the cylindrical portion 433. The guide member 430 is fixed to the cylindrical portion 414 of the valve seat 410.

  In the middle of the cylindrical portion 433 of the guide member 430 in the front-rear direction, a plurality of windows 433b that communicate between the inside and the outside of the cylindrical portion 433 are provided so as to be arranged on a circumference centered on the axis X1.

  The valve body 420 is accommodated in a space surrounded by the cylindrical portion 414 of the valve seat 410 and the guide member 430. The valve body 420 has a cylindrical convex portion 421 with the axis X1 as a central axis, a disc-shaped disc portion 425 that closes the front of the convex portion 421, and protrudes forward from the disc portion 425. It consists of a convex portion 426 having a cylindrical shape as a central axis. A permanent magnet 450 is fixed to the inner periphery of the convex portion 421 in the valve body 420 by press-fitting on the side opposite to the valve hole 411.

  The permanent magnet 450 is disposed at a position recessed from the valve body seating surface 426 a with a step D including the disk portion 425. The permanent magnet 450 has a columnar shape concentric with the valve hole 411 with the axis X1 as the central axis. The front end surface of the convex portion 426 is a valve seat surface 426a. A foreign substance storage portion 426 c is formed on the inner periphery of the convex portion 426. Other configurations are the same as those of the first embodiment.

  In this differential pressure control valve, as shown in FIG. 14, the permanent magnet 450 has a predetermined magnetic flux that allows the valve seat 410 and the valve body 420 to be seated when seated against the valve seat surface 414a and the valve body seat surface 426a. Acting density. For this reason, the valve seat surface 414a and the valve body seat surface 426a can be contacted at the time of seating.

  Even in a state where the valve body 420 is seated on the valve seat 410, the foreign substance storage portion 426 c exists in front of the disc portion 425. FIG. 13 shows magnetic flux lines at the time of sitting. At the time of separation, the distance between the valve body 420 and the valve seat 410 increases, so the magnetic flux line from the permanent magnet 450 changes from when the valve is closed, and the magnetic flux line passes through the valve body 420 closer to the valve seat 410. For this reason, the area | region where a magnetic flux line concentrates between the permanent magnet 450 and the valve body 420 generate | occur | produces, and a foreign material is attracted. The sucked foreign matter is accommodated in the foreign matter accommodation portion 426c. On the other hand, the magnetic flux density on the valve seat surface 426a and the valve body seat surface 414a at the time of sitting is lower than those on the seating. In addition, the magnetic flux density in the foreign matter container 426c during the separation is higher than the magnetic flux densities of the valve seat surface 414a and the valve body seat surface 426a during the separation. For this reason, the foreign matter is not attracted to the valve seat surface 414a and the valve body seat surface 426a, and is accommodated in the foreign matter accommodation portion 426c. In addition, since the foreign material storage part 426c is on the back side of the permanent magnet 450 with the disk part 425 interposed therebetween, the stored foreign material remains in the foreign material storage part 426c even if the valve body 420 is separated from the valve seat 410. . Other functions and effects are the same as those of the first embodiment.

(Reference Example 4)
As shown in FIG. 15, the differential pressure control valve 500 of Reference Example 4 is disposed in the large-diameter hole 50 a of the discharge passage 50. The differential pressure control valve 500 includes a valve seat 510, a guide member 530, and a valve body 520.

  The valve seat 510 includes a base portion 513 having an axis X1 as a central axis, and a cylindrical portion 514 that is concentric with the base portion 513 and has a small diameter, and is located rearward of the base portion 513. A valve hole 511 having an axis X1 as a central axis is provided through the base 513 and the cylindrical portion 514. The tip of the cylindrical portion 514 facing the rear is a valve seat surface 514a.

  The guide member 530 includes a cylindrical portion 533 having a cylindrical shape with the axis X1 as a central axis, and a disk portion 534 having a disk shape that closes the rear end edge of the cylindrical portion 533. The guide member 530 is fixed to the cylindrical portion 514 of the valve seat 510.

  In the middle of the cylindrical portion 533 of the guide member 530 in the front-rear direction, a plurality of windows 533b that communicate the inside and the outside of the cylindrical portion 533 are provided so as to be arranged on a circumference centered on the axis X1.

  The valve body 520 is accommodated in a space surrounded by the cylindrical portion 514 of the valve seat 510 and the guide member 530. The valve body 520 includes a convex portion 521 having a cylindrical shape with the axis X1 as a central axis, and a disc portion 525 provided integrally in a disc shape behind the convex portion 521. A permanent magnet 550 is fixed to the outer periphery of the convex portion 521 by press-fitting.

  The permanent magnet 550 is disposed at a position recessed from the valve seat surface 526a with a step D. The permanent magnet 550 has an annular shape concentric with the valve hole 511 with the axis X1 as the central axis.

  The convex portion 521 has a convex portion 526 in front of the permanent magnet 550. The front end surface of the convex portion 526 is a valve seat surface 526a. A foreign substance storage portion 526 c is formed on the outer periphery of the convex portion 526. Other configurations are the same as those of the first embodiment. This differential pressure control valve 500 can provide the same effects as those of the first embodiment.

(Example 2)
As illustrated in FIG. 16, the differential pressure control valve 600 according to the second embodiment includes a valve seat 610, a guide member 630, and a valve body 620.

  The valve seat 610 includes a base portion 613 having an axis X1 as a central axis, and a cylindrical portion 614 that is concentric with the base portion 613 and has a small diameter, and is positioned rearward of the base portion 613.

  A valve hole 611 having an axis X1 as a central axis is provided through the base 613 and the cylindrical portion 614. The cylindrical portion 614 includes a small-diameter convex portion 615 located on the distal end side, and a guide member holding portion 616 that is positioned between the convex portion 615 and the base portion 613 and has a slightly larger diameter than the convex portion 615. The outer periphery of the convex portion 615 is a notch 615b. The front end of the convex portion 615 facing the rear is a valve seat surface 615a.

  The guide member 630 includes a cylindrical portion 633 having a cylindrical shape with the axis X1 as a central axis, and a disk portion 634 that blocks the rear end edge of the cylindrical portion 633. The front end edge 633a of the cylindrical portion 633 is fitted to the outer peripheral surface of the guide member holding portion 616 from the outside, whereby the guide member 630 is fixed to the valve seat 610. The guide member 630 is made of a resin (nylon resin or the like) that is a nonmagnetic material.

  In the middle of the cylindrical portion 633 in the front-rear direction, a plurality of windows 633b that allow the inside and the outside of the cylindrical portion 633 to communicate with each other are provided so as to be arranged on a circumference centered on the axis X1. Each window 633b is formed in a quadrangle.

  The valve body 620 is accommodated in a space surrounded by the cylindrical portion 614 of the valve seat 610 and the guide member 630, and is located downstream of the discharge passage 50 with respect to the valve seat 610. The valve body 620 includes a disk part 625 having a disk shape with the axis X1 as a central axis, and a cylindrical part 621 having a cylindrical shape integrally formed with the disk part 625 with the disk part 625 positioned at the front end. In this embodiment, the disk portion 625 is a valve body body made of iron (S45C or the like). The cylindrical portion 621 is made of the same type of resin as the guide member 630.

  The outer diameter of the disk portion 625 is substantially equal to the outer diameter of the convex portion 615, and the outer peripheral area of the front end surface of the disk portion 625 is a valve seat surface 625a.

  A permanent magnet 650 is fixed to the notch 615b of the valve seat 610 by press fitting. The permanent magnet 650 is disposed at a position recessed with a step D from the valve seat surface 615a. As shown in FIG. 17, in the notch 615b, a space from the front end surface 650a of the permanent magnet 650 to the valve seat surface 615a is defined as a first foreign object storage portion 615c. A second foreign material container 625b that is integrated with the first foreign material container 615c when the valve is closed is formed on the outer periphery of the disk portion 625. The tip surface 650a of the permanent magnet 650 is recessed. More specifically, the tip surface 650a of the permanent magnet 650 has a taper with a step D larger in the direction closer to the valve seat surface 615a and the valve body seat surface 625a than in the side far from the valve seat surface 615a and the valve body seat surface 625a. It is formed in a shape.

  In the differential pressure control valve 600, as shown in FIGS. 18 and 19, the magnetic flux density in the first and second foreign matter storage portions 615c and 625b at the time of separation is the same as that in the first and second foreign matter storage portions 615c and 625b at the time of seating. The permanent magnet 650 is arranged so as to be higher than the magnetic flux density. In addition, the permanent magnet 650 is arranged so that the magnetic flux density in the first and second foreign matter storage portions 615c and 625b at the time of separation is higher than the magnetic flux density on the valve seat surface 615a and the valve body seat surface 625a at the time of separation. Has been. Further, the difference in magnetic flux density between the valve seat surface 615a and the first and second foreign matter storage portions 615c and 625b is increased. Other configurations are the same as those of the first embodiment.

  In this differential pressure control valve 600, the difference in magnetic flux density between the valve seat surface 615a and the first and second foreign matter storage portions 615c and 625b is large, so that the difference between the valve seat surface 615a and the valve body seat surface 625a. Foreign matter is harder to bite.

  Further, in the differential pressure control valve 600, the first and second foreign substance storage portions 615c and 625b are located on the tip side of the permanent magnet 650, and the tip surface 650a of the permanent magnet 650 is recessed. Thereby, the 1st, 2nd foreign material accommodating part 615c, 625b can be enlarged, and many foreign materials can be accommodated. Further, since the tip surface 650a is formed in a tapered shape, a region where magnetic flux is concentrated is generated between the tip surface 650a and the valve seat surface 615a, and foreign matter can be reliably adsorbed. Foreign matter is less likely to be caught between the seat surface 615a and the valve body seat surface 625a.

  Further, in this differential pressure control valve 600, since the cylindrical portion 621 of the valve body 620 is made of the same type of resin as the guide member 630, foreign matter is difficult to bite between the guide member 630 and the cylindrical portion 621. Other functions and effects are the same as those of the first embodiment.

(Example 3)
As shown in FIG. 20, in the differential pressure control valve 700 of the third embodiment, the tip surface 651a of the permanent magnet 651 is closer to the valve seat surface 615a and the valve body seat surface 625a. The step D is formed in a two-step shape having a larger step D than the one far from the seating surface 625a. Other configurations are the same as those of the first embodiment. Also in this differential pressure control valve 700, the same effects as those of the second embodiment can be achieved.

In the above, the present invention has been described with reference to the first to third embodiments. However, the present invention is not limited to the first to third embodiments, and can be appropriately modified and applied without departing from the spirit of the present invention. Needless to say.

  For example, the differential pressure control valves 100, 200, 300, 400, 500, 600, 700 may be directed in the vertical direction, or may be provided at a position other than the rear housing 5.

  The present invention can be used for an air conditioner or the like.

100, 200, 300, 400, 500, 600, 700 ... Differential pressure control valve 110, 210, 310, 410, 510, 610 ... Valve seat, valve seat body 111, 211, 311, 411, 511, 611 ... Valve hole 115, 214, 321, 421, 521 , 615 ... convex portion 115b, 214d, 615b ... notch 115a, 214a, 314a, 414a, 514a, 615a ... valve seat surface 120, 220, 320, 420, 520, 620 ... Valve body, valve body 625 ... Disc (valve body)
125a, 225a, 321a, 426a, 526a, 625a ... valve body seating surfaces 130, 230, 330, 430, 530, 630 ... guide members 150, 250, 350, 450, 550, 650 ... permanent magnets 115c, 125b, 214c, 321c, 426c, 526c, 615c, 625b ... foreign matter accommodating portion
31 ... Compression chamber 5b ... Discharge chamber 50 ... Discharge passage

Claims (8)

A valve seat having a valve hole through which a fluid passes, and a seat located on the downstream side with respect to the valve seat, and seated on or separated from the valve seat according to a pressure difference between the upstream side and the downstream side In the differential pressure control valve comprising a valve body that opens and closes the valve hole,
The valve seat is made of a magnetic material, and has a valve seat body in which a valve seat surface is formed around the valve hole,
The valve body is made of a magnetic material, and has a valve body main body formed with a valve body seating surface that is seated or separated from the valve seating surface,
The valve seat is provided with a permanent magnet that urges the valve seat body and the valve body body so as to approach each other by an attractive force at a position recessed from the valve seat surface ,
In the vicinity of the valve seat surface, a foreign object storage part is provided that is disposed in a notch formed in the valve seat surface and can store a foreign material made of a magnetic material,
The valve body main body is formed in a convex shape with the tip being the valve body seat surface, and the notch is formed on the outer periphery.
The permanent magnet, differential pressure control valve the magnetic flux density in the dust containing portion during the separating is characterized by a high of Turkey than the magnetic flux density in the dust containing part of the time of sitting.   The said permanent magnet is arrange | positioned so that the magnetic flux density in the said foreign material accommodating part at the time of separation may become higher than the magnetic flux density in the said valve seat surface at the time of separation and the said valve body seat surface. The differential pressure control valve. 3. The differential pressure control valve according to claim 2 , wherein, when the foreign matter storage portion is located on the tip side of the permanent magnet, the tip surface of the permanent magnet is recessed. 4. The differential pressure control valve according to claim 3 , wherein the tip surface has a larger step difference in a direction closer to the valve seat surface and the valve body seat surface than in a direction far from the valve seat surface and the valve body seat surface. The permanent magnet is the valve hole concentric annular a differential pressure control valve according to any one of claims 1 to 4. The differential pressure control valve according to claim 5 , wherein the valve seat body has a convex portion that is formed in a cylindrical shape with a tip formed as the valve seat surface. The differential pressure control valve according to any one of claims 1 to 6 , further comprising a guide member made of a nonmagnetic material that is fixed to the valve seat and guides the valve body. A compression chamber and a discharge chamber; the fluid sucked into the compression chamber can be compressed and discharged into the discharge chamber; and the discharge capacity of the fluid discharged from the compression chamber into the discharge chamber is changed A variable capacity compressor configured to be possible,
8. The variable displacement compressor according to claim 1, wherein the differential pressure control valve according to any one of claims 1 to 7 is disposed in the discharge chamber or a discharge passage communicating with the discharge chamber.

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