JP3733899B2 - Solenoid valve of variable capacity compressor and method of manufacturing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electromagnetic valve used in a variable displacement compressor that constitutes a refrigerant circulation circuit and can change a refrigerant discharge capacity based on a pressure in a control pressure region, and a method for manufacturing the same.
[0002]
[Prior art]
As this type of solenoid valve, for example, a control valve for a variable displacement compressor having a configuration disclosed in Japanese Patent Laid-Open No. 2000-291542 is known. In this configuration, a movable iron core (iron core) fixed to the valve body is accommodated in the control valve (electromagnetic valve) so as to reciprocate in an accommodation cylinder (accommodating member) provided in the control valve. Yes.
[0003]
A coil (solenoid) is provided inside the housing (solenoid housing) of the solenoid part and outside the housing cylinder. The coil can apply an external force to a bellows (pressure-sensitive member) connected to the valve body by applying an electromagnetic force generated by the coil to the movable iron core.
[0004]
In general, a refrigerant is introduced into the housing member, and the housing member and the solenoid housing are fixed to each other by brazing in order to prevent leakage of the refrigerant through the joint portion.
[0005]
The housing member is generally formed using stainless steel (nonmagnetic material). The purpose of this is to make the magnetic flux generated by the solenoid act efficiently on the iron core by forming the housing member using stainless steel, which is a nonmagnetic material. For example, when the housing member is formed using iron, which is a magnetic material, there is a possibility that the magnetic flux generated by the solenoid leaks to a portion other than the iron core through the housing member. By using stainless steel, it is possible to avoid the inconvenience.
[0006]
Further, the solenoid housing is generally formed using iron (magnetic material), and plating treatment for rust prevention is required.
In general, the housing member and the solenoid housing are plated in a state where they are fixed to each other by brazing. At this time, in order to prevent the plating solution from entering the housing member, the opening of the housing member is subjected to a masking process. In this masking process, for example, as shown in FIG. 4, the opening of the housing member 91 in a state where the housing member 91 (specifically, the opening side thereof) and the solenoid housing 92 are fixed to each other by brazing. A masking material 93 made of rubber is inserted into this. In this state, the housing member 91 and the solenoid housing 92 are immersed in the plating solution together with the masking material 93.
[0007]
For example, when a plating solution enters the inside of the housing member, a plating layer may be formed on the inner surface of the housing member. In this case, since the fixing strength of the plating layer with respect to stainless steel is weaker than that with respect to iron, there is a concern that the plating layer may be peeled off due to sliding contact with the iron core that reciprocates in the housing member. . If a piece of the plating layer that has been peeled off exists in the housing member, this piece may adversely affect the reciprocation of the iron core in the housing member. The masking process is performed to avoid these.
[0008]
Conventionally, galvanization has been used in the plating process.
[0009]
[Problems to be solved by the invention]
However, when the masking process is performed and the plating process is performed as described above, the work for the masking process is troublesome and becomes an obstacle to cost reduction. In addition, when a gap is generated between the masking material used for the masking process and the housing member, the plating solution may enter the housing member through the gap.
[0010]
In order to solve these problems, for example, a method may be considered in which the solenoid housing alone is plated and the plated solenoid housing and the housing member are fixed to each other by brazing. However, since the transformation temperature of the galvanized layer is lower than the maximum temperature of the brazing part during the brazing process, the galvanized layer of the solenoid housing is overheated during the brazing process in the above-described method. May be removed.
[0011]
An object of the present invention is to provide a variable displacement compression that can maintain the plated layer of the solenoid housing well, reliably avoid the formation of the plated layer in the housing member, and reduce the cost. It is to provide a solenoid valve for a machine and a method for manufacturing the same.
[0012]
[Means for Solving the Problems]
In order to solve the above-described problems, in the invention according to claim 1, the electromagnetic valve constitutes a refrigerant circulation circuit and can change the refrigerant discharge capacity based on the pressure in the control pressure region. Used for. The electromagnetic valve includes a valve chamber, a valve body, an iron core, a housing member, a solenoid, and a solenoid housing. In the electromagnetic valve, the valve chamber is provided to constitute a part of a gas passage for introducing a high-pressure refrigerant gas into the control pressure region or discharging the refrigerant gas from the control pressure region. ing. The valve body is provided in the valve chamber so that the position thereof can be changed, and the opening degree of the gas passage can be changed by the position change in order to control the pressure in the control pressure region. Moreover, the said iron core is connected with the said valve body so that a movement is possible integrally. The housing member is made of a nonmagnetic material and is configured to house the iron core so as to be capable of reciprocating. The solenoid is provided outside the housing member. Furthermore, the solenoid is configured to generate an electromagnetic force that acts on the iron core and is involved in the positioning operation of the valve body. The solenoid housing is made of a magnetic material and can accommodate the solenoid. The solenoid housing and the housing member are fixed to each other by brazing in a state where the solenoid housing is nickel-plated.
[0013]
In the present invention, nickel plating is performed on the solenoid housing. Therefore, the brazing process can be performed in a state where the solenoid housing is plated. That is, since the heat-resistant temperature (transformation temperature) of the plating layer formed by the nickel plating process is higher than the maximum temperature in the brazing part during the brazing process, the plating layer is removed during the brazing process. Therefore, the state in which the plated layer covers the surface of the solenoid housing in the brazed portion can be maintained well.
[0014]
Therefore, for example, compared with the case where the solenoid housing and the housing member fixed to each other by brazing are plated, the masking process for preventing the plating solution from entering the housing member is performed without performing a masking process or the like. The formation of a plating layer on the inner surface of the housing member can be prevented. As a result, it is possible to reduce the cost associated with the abolition of the masking process.
[0015]
Further, as described above, when the masking process and the plating process are performed on the solenoid housing and the housing member fixed to each other by brazing, a gap between the masking material used for the masking process and the housing member is formed. There is a risk that the plating solution may enter the housing member. In the present invention, since it is possible not to perform the plating process on the housing member, it is possible to completely avoid the situation where the plating solution enters the housing member.
[0016]
According to a second aspect of the present invention, in the first aspect of the present invention, the solenoid housing functions as a solenoid yoke that forms a magnetic path of electromagnetic force generated by the solenoid.
[0017]
According to the present invention, by configuring the solenoid housing to function as a solenoid yoke, it is possible to efficiently apply an electromagnetic force to the iron core, and it is not necessary to provide a special solenoid yoke.
[0018]
In the invention of claim 3, in the invention of claim 1 or 2, the housing member is made of stainless steel and the solenoid housing is made of iron.
[0019]
According to the present invention, the housing member and the solenoid housing are formed using stainless steel and iron, which are excellent in marketability, respectively. Therefore, it is relatively inexpensive and easy to make the housing member and the solenoid housing each made of a non-magnetic material and a magnetic material.
[0020]
According to a fourth aspect of the invention, in the invention according to any one of the first to third aspects, the electromagnetic valve is adapted to change in a pressure difference between two pressure monitoring points set in the refrigerant circulation circuit. Based on the displacement of the pressure-sensitive member, the position of the valve body is changed so that the refrigerant discharge capacity is changed to the side that cancels the fluctuation of the pressure difference. Further, the electromagnetic valve is configured to change a set differential pressure that is a reference for the positioning operation of the valve body by the pressure-sensitive member by changing a force applied to the pressure-sensitive member by external control. Has been.
[0021]
According to this invention, the refrigerant discharge capacity can be directly controlled from the outside. Further, for example, the control for keeping the refrigerant flow rate of the refrigerant circulation circuit below a predetermined amount can be performed with high accuracy and good response without using a refrigerant flow rate sensor or the like.
[0022]
In the invention according to claim 5, the solenoid valve that is the object of the manufacturing method is used in a variable capacity compressor that constitutes a refrigerant circulation circuit and that can change the refrigerant discharge capacity based on the pressure in the control pressure region. . The electromagnetic valve includes a valve chamber, a valve body, an iron core, a housing member, a solenoid, and a solenoid housing. In the electromagnetic valve, the valve chamber is provided to constitute a part of a gas passage for introducing a high-pressure refrigerant gas into the control pressure region or discharging the refrigerant gas from the control pressure region. ing. The valve body is provided in the valve chamber so that the position thereof can be changed, and the opening degree of the gas passage can be changed by the position change in order to control the pressure in the control pressure region. Moreover, the said iron core is connected with the said valve body so that a movement is possible integrally. The housing member is made of a nonmagnetic material and is configured to house the iron core so as to be capable of reciprocating. The solenoid is provided outside the housing member. Furthermore, the solenoid is configured to generate an electromagnetic force that acts on the iron core and is involved in the positioning operation of the valve body. The solenoid housing is made of a magnetic material and can accommodate the solenoid. The manufacturing method of the present invention is characterized in that the solenoid housing and the housing member are fixed to each other by brazing in a process after the plating process for nickel-plating the solenoid housing.
[0023]
According to the present invention, for example, compared to the case where the plating process is performed on the both in the process after the brazing process in which the solenoid housing and the housing member are fixed to each other by brazing, the plating solution into the housing member It is not necessary to perform a masking process or the like for preventing intrusion. That is, it is possible to reduce the cost associated with the abolition of the masking process. In addition, since it is not necessary to immerse the housing member in the plating solution, formation of a plating layer on the inner surface of the housing member can be reliably avoided.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. In FIG. 1, the left side of the drawing is the front side of the compressor and the right side is the rear side.
[0025]
As shown in FIG. 1, a compressor C as a variable capacity compressor constituting a vehicle air conditioner includes a cylinder block 11, a front housing 12 joined and fixed to the front end thereof, and a rear end of the cylinder block 11. And a rear housing 14 joined and fixed via a valve forming body 13. The cylinder block 11, the front housing 12, the valve forming body 13, and the rear housing 14 constitute a housing for the compressor C.
[0026]
A crank chamber 15 as a control pressure region is defined in a region surrounded by the cylinder block 11 and the front housing 12.
A rotating shaft 16 disposed so as to penetrate the crank chamber 15 is rotatably supported by the housing. The front end portion side of the rotating shaft 16 is supported by a radial bearing 12 </ b> A fixed to the front wall of the front housing 12. The rear end side of the rotary shaft 16 is supported by a radial bearing 11 </ b> A fixed to the cylinder block 11.
[0027]
The front end portion of the rotating shaft 16 is disposed so as to protrude through the front wall of the front housing 12. The front end portion of the rotary shaft 16 is operatively connected to a vehicle engine E as an external drive source via a power transmission mechanism (not shown).
[0028]
A seal member 12B is provided between the front end portion of the rotating shaft 16 and the front wall of the front housing 12 at a portion outside the radial bearing 12A. The seal member 12B pressure-isolates the inside and the outside of the housing with the seal member 12B interposed therebetween.
[0029]
A lug plate 19 is fixed to the rotary shaft 16 so as to be integrally rotatable in the crank chamber 15. The crank chamber 15 accommodates a swash plate 20 as a cam plate. The swash plate 20 is supported so as to be slidable and tiltable with respect to the rotary shaft 16. The swash plate 20 is operatively connected to the lug plate 19 via a hinge mechanism 21. The swash plate 20 can be rotated synchronously with the lug plate 19 and the rotary shaft 16 by the operation connection with the lug plate 19 via the hinge mechanism 21 and the support of the rotary shaft 16, and the rotation center axis of the rotary shaft 16. It can be tilted with respect to the rotary shaft 16 while being slid in the direction.
[0030]
The swash plate 20 defines a minimum inclination angle of the swash plate 20 by a locking ring 22 fixed to the rotating shaft 16 and a spring 23 disposed between the locking ring 22 and the swash plate 20. It has come to be. The minimum inclination angle of the swash plate 20 means an inclination angle in a state where the angle between the swash plate 20 and the axis direction of the rotary shaft 16 is closest to 90 °.
[0031]
A plurality of cylinder bores 24 (only one is shown in FIG. 1) are formed through the cylinder block 11 so as to extend along the rotation center axis direction of the rotation shaft 16. In the cylinder bore 24, a single-headed piston 25 is accommodated so as to be able to reciprocate. The front and rear openings of the cylinder bore 24 are closed by the valve forming body 13 and the piston 25, and a compression chamber whose volume changes according to the reciprocation of the piston 25 is defined in the cylinder bore 24. Each piston 25 is anchored to the outer periphery of the swash plate 20 via a shoe 26. Thereby, the rotational motion of the swash plate 20 accompanying the rotation of the rotating shaft 16 is converted into the reciprocating linear motion of the piston 25 via the shoe 26.
[0032]
The cylinder block 11 (cylinder bore 24), the rotary shaft 16, the lug plate 19, the swash plate 20, the hinge mechanism 21, the piston 25, and the shoe 26 constitute a variable displacement piston compression mechanism.
[0033]
The rear housing 14 has a suction chamber 27 as a suction pressure region and a discharge chamber 28 as a discharge pressure region. The front sides of the suction chamber 27 and the discharge chamber 28 are closed by the valve forming body 13. The refrigerant gas in the suction chamber 27 is moved from the top dead center side to the bottom dead center side of each piston 25 through the suction port 29 and the suction valve 30 formed in the valve forming body 13 and the cylinder bore 24 (compression chamber). To be introduced. The low-pressure refrigerant gas introduced into the cylinder bore 24 is compressed to a predetermined pressure by the movement from the bottom dead center side to the top dead center side of the piston 25, and the discharge port 31 and the discharge valve formed in the valve forming body 13. It is introduced into the discharge chamber 28 via 32.
[0034]
The suction chamber 27 and the discharge chamber 28 are connected by an external refrigerant circuit 33. The external refrigerant circuit 33 includes a condenser (condenser) 34, a temperature expansion valve 35 as a decompression device, and an evaporator (evaporator) 36. The opening degree of the expansion valve 35 is feedback-controlled based on a detected temperature and an evaporation pressure (an outlet pressure of the evaporator 36) of a temperature sensing cylinder (not shown) provided on the outlet side or the downstream side of the evaporator 36. The expansion valve 35 adjusts the refrigerant flow rate in the external refrigerant circuit 33 by supplying liquid refrigerant commensurate with the heat load to the evaporator 36.
[0035]
In the downstream area of the external refrigerant circuit 33, a refrigerant gas flow pipe 37 that connects the outlet of the evaporator 36 and the suction chamber 27 of the compressor C is provided. In the upstream area of the external refrigerant circuit 33, a refrigerant flow pipe 38 that connects the discharge chamber 28 of the compressor C and the inlet of the condenser 34 is provided. The compressor C sucks and compresses the refrigerant gas introduced into the suction chamber 27 from the downstream area of the external refrigerant circuit 33 and discharges the compressed gas to the discharge chamber 28 connected to the upstream area of the external refrigerant circuit 33.
[0036]
The compressor C and the external refrigerant circuit 33 constitute a cooling circuit (that is, a refrigerant circulation circuit) of the vehicle air conditioner.
In the housing, an extraction passage 41 (gas passage) that connects the crank chamber 15 and the suction chamber 27 is formed so as to penetrate the cylinder block 11 and the valve forming body 13. The housing is provided with an air supply passage 42 (gas passage) that allows the discharge chamber 28 and the crank chamber 15 to communicate with each other. The opening degree of the air supply passage 42 can be adjusted by a control valve 43 disposed on the air supply passage 42 (in the middle of the air supply passage 42).
[0037]
By adjusting the opening of the control valve 43, the balance between the amount of high-pressure refrigerant gas introduced into the crank chamber 15 via the air supply passage 42 and the amount of gas discharged from the crank chamber 15 via the extraction passage 41 is controlled. The crank pressure (inner pressure in the crank chamber 15) Pc is determined. In accordance with the change in the crank pressure Pc, the difference between the crank pressure Pc through the piston 25 and the internal pressure in the compression chamber is changed, and the inclination angle of the swash plate 20 is changed. The capacity (the refrigerant discharge capacity per one rotation of the rotating shaft 16) is adjusted.
[0038]
In the compressor C of the present embodiment, the refrigerant discharge capacity per one rotation of the rotary shaft 16 is substantially zero when the inclination angle of the swash plate 20 is the minimum inclination angle. Has been.
[0039]
As the flow rate of refrigerant flowing through the refrigerant circuit (refrigerant flow rate Q) increases, the pressure loss per unit length of the circuit or piping also increases. That is, the pressure loss (differential pressure) between the two pressure monitoring points P1 and P2 set in the refrigerant circulation circuit shows a positive correlation with the refrigerant flow rate Q in the circuit. Therefore, grasping the differential pressure between the two pressure monitoring points P1 and P2 (PdH−PdL = differential pressure ΔPX between the two points) is nothing other than indirectly detecting the refrigerant flow rate Q in the refrigerant circulation circuit.
[0040]
In the present embodiment, a pressure monitoring point P1 as an upstream high pressure monitoring point is defined in the discharge chamber 28 corresponding to the most upstream area of the flow pipe 38, and a downstream low pressure is placed in the middle of the flow pipe 38 that is a predetermined distance away from it. A pressure monitoring point P2 is determined as a monitoring point. The gas pressure PdH at the pressure monitoring point P1 is passed through the first pressure detection passage 44 (see FIG. 2), and the gas pressure PdL at the pressure monitoring point P2 is passed through the second pressure detection passage 45 (see FIG. 2). To the control valve 43 respectively.
[0041]
In the flow pipe 38, between the pressure monitoring points P1 and P2, a fixed throttle 46 is disposed as a means for expanding the pressure difference between the two points. The fixed throttle 46 serves to clarify (enlarge) the differential pressure ΔPX between the two points P1 and P2 without setting the distance between the pressure monitoring points P1 and P2 so far. In this way, by providing the fixed throttle 46 between the pressure monitoring points P 1 and P 2, the pressure monitoring point P 2 can be set particularly close to the compressor C. As a result, the pressure monitoring point P 2 and the control valve 43 The second pressure detection passage 45 therebetween can be shortened. Note that the pressure PdL at the pressure monitoring point P2 is set to a sufficiently high pressure compared to the crank pressure Pc even when the pressure PdL is lower than PdH due to the action of the fixed throttle 46.
[0042]
As shown in FIG. 2, a valve chamber 48, a communication passage 49, and a pressure sensitive chamber 50 are defined in the valve side housing 47 of the control valve 43. An operating rod 51 is disposed in the valve chamber 48 and the communication passage 49 so as to be movable in the axial direction (vertical direction in the drawing).
[0043]
The communication passage 49 and the pressure sensing chamber 50 are blocked by the upper end portion of the operating rod 51 inserted into the communication passage 49. The valve chamber 48 communicates with the discharge chamber 28 via the upstream portion of the air supply passage 42. The communication passage 49 is in communication with the crank chamber 15 via the downstream portion of the air supply passage 42. The valve chamber 48 and the communication passage 49 constitute a part of the air supply passage 42 (gas passage).
[0044]
In the valve chamber 48, a valve body 52 formed at the intermediate portion of the operating rod 51 is disposed. The step located at the boundary between the valve chamber 48 and the communication passage 49 forms a valve seat 53, and the communication passage 49 forms a kind of valve hole. When the operating rod 51 moves upward from the position shown in FIG. 2 (the lowest movement position) to the highest movement position where the valve body 52 is seated on the valve seat 53, the communication passage 49 is blocked. That is, the valve body 52 of the operating rod 51 functions as a valve body capable of adjusting the opening degree of the air supply passage 42.
[0045]
A pressure sensitive member 54 made of bellows is accommodated in the pressure sensitive chamber 50. The upper end portion of the pressure sensitive member 54 is fixed to the valve side housing 47. The upper end portion of the operating rod 51 is fitted into the lower end portion of the pressure sensitive member 54. The pressure-sensitive chamber 50 includes a first pressure chamber 55 that is an inner space of the pressure-sensitive member 54 and a second pressure chamber 56 that is an outer space of the pressure-sensitive member 54 by a pressure-sensitive member 54 having a substantially bottomed cylindrical shape. It is divided into and. The pressure PdH at the pressure monitoring point P1 is introduced into the first pressure chamber 55 via the first pressure detection passage 44, and the pressure monitoring point is introduced into the second pressure chamber 56 via the second pressure detection passage 45. A pressure PdL of P2 is introduced. The pressure sensitive member 54, the pressure sensitive chamber 50, and the like constitute a pressure sensitive mechanism.
[0046]
An electromagnetic actuator portion 57 as a set differential pressure changing means is provided below the valve-side housing 47, and a solenoid side housing 58 made of iron (magnetic material) as a solenoid housing constituting the electromagnetic actuator portion 57. Is fixed. In this embodiment, the solenoid side housing 58 is formed using SWCH (carbon steel wire for cold heading).
[0047]
A stainless steel (nonmagnetic material) housing cylinder 59 as a bottomed cylindrical housing member is fixed to the center of the solenoid-side housing 58. The end of the housing cylinder 59 on the opening side (upper side in FIG. 2) is in a state of being inserted into a through hole 58 </ b> A formed in the central part in the solenoid housing 58.
[0048]
A center post 60 is fitted and fixed in a portion of the housing cylinder 59 on the opening side. Due to the insertion of the center post 60, a plunger chamber 61 is defined in the lower part of the housing cylinder 59.
[0049]
A plunger 62 as an iron core is accommodated in the plunger chamber 61 so as to be movable in the axial direction of the operating rod 51. An insertion hole 60A extending in the axial direction is formed in the center of the center post 60, and the lower end side of the operating rod 51 is disposed in the insertion hole 60A so as to be movable in the axial direction. The lower end of the operating rod 51 is fitted and fixed in a hole formed in the plunger 62. That is, the plunger 62 and the operation rod 51 are connected so as to be movable integrally.
[0050]
The plunger chamber 61 communicates with the valve chamber 48 through a gap between the insertion hole 60 </ b> A and the operating rod 51. That is, the inside of the housing cylinder 59 is in communication with the valve chamber 48. A joint portion between the housing cylinder 59 and the solenoid-side housing 58 (specifically, a joint portion between the outer peripheral surface of the opening-side end portion of the housing cylinder 59 and the inner peripheral surface of the through hole 58A opposed thereto) is brazed. It is fixed by. Thereby, the leakage of the refrigerant from the inside to the outside of the housing cylinder 59 via the joint portion is prevented. In the present embodiment, copper brazing using a copper brazing material is employed for the brazing.
[0051]
In the plunger chamber 61, a plunger biasing spring 63 made of a coil spring is accommodated between the center post 60 and the plunger 62. The plunger urging spring 63 acts in a direction in which the plunger 62 is separated from the center post 60 to urge the operating rod 51 (valve element portion 52) downward in the drawing. Further, the operating rod 51 is biased downward in the drawing based on the spring property of the pressure-sensitive member 54 itself. Hereinafter, the biasing force based on the spring property of the pressure-sensitive member 54 is referred to as a bellows spring force.
[0052]
In the solenoid-side housing 58, a coil 64 as a solenoid is disposed on the outer peripheral side of the housing cylinder 59 in a range straddling the center post 60 and the plunger 62. Electric power is supplied to the coil 64 from a battery (not shown) via a drive circuit 68 based on a command from the control device 67.
[0053]
By supplying power to the coil 64 described above, an electromagnetic force (electromagnetic attractive force) having a magnitude corresponding to the amount of power supply is generated between the plunger 62 and the center post 60. Based on this electromagnetic force, an upward force acts on the operating rod 51 via the plunger 62. The energization control to the coil 64 is performed by adjusting the applied voltage, and PWM (pulse width modulation) control, that is, duty control is adopted for adjusting the applied voltage.
[0054]
In the present embodiment, the solenoid-side housing 58 functions as a solenoid yoke that forms a magnetic path of electromagnetic force generated by the coil 64. As a result, the electromagnetic force acts efficiently on the center post 60 and the plunger 62.
[0055]
In the control valve 43, the arrangement position of the actuating rod 51 (valve element 52), that is, the valve opening is determined as follows.
First, when the coil 64 is not energized (duty ratio = 0%), the actuating rod 51 is arranged with the downward biasing force of the drawing by the bellows spring force and the downward biasing force of the plunger biasing spring 63 in the drawing. Is dominant. Therefore, the operating rod 51 is disposed at the lowest position, and the valve body 52 opens the communication passage 49 fully. For this reason, the crank pressure Pc becomes the maximum value that can be taken under the situation at that time, and the difference between the crank pressure Pc and the internal pressure of the compression chamber via the piston 25 increases. As a result, the inclination angle of the swash plate 20 is minimized, and the refrigerant discharge capacity per rotation of the rotating shaft 16 in the compressor C is minimized.
[0056]
Next, when the coil 64 is energized with the minimum duty ratio (> 0%) in the variable duty ratio range in the control valve 43, the upward electromagnetic force in the drawing is lowered by the bellows spring force and the plunger biasing spring 63. The urging force is exceeded, and the operating rod 51 starts to move upward. In this state, the upward electromagnetic force reduced by the downward biasing force of the plunger biasing spring 63 opposes the downward pressing force based on the differential pressure ΔPX between the two points biased by the bellows spring force (downward biasing force). . Then, the valve body 52 of the operating rod 51 is positioned with respect to the valve seat 53 at a position where these vertical biasing forces are balanced.
[0057]
For example, when the refrigerant flow rate in the refrigerant circulation circuit decreases due to a decrease in the rotational speed of the vehicle engine E, the force based on the downward two-point differential pressure ΔPX acting on the operating rod 51 decreases. Therefore, the operating rod 51 (valve body portion 52) moves up, the opening degree of the communication passage 49 decreases, and the crank pressure Pc tends to decrease. For this reason, the swash plate 20 tilts in the inclination angle increasing direction, and the refrigerant discharge capacity of the compressor C is increased. When the refrigerant discharge capacity increases, the refrigerant flow rate in the refrigerant circuit also increases, and the two-point differential pressure ΔPX increases.
[0058]
Conversely, when the refrigerant flow rate in the refrigerant circuit increases due to an increase in the rotational speed of the vehicle engine E, the force based on the downward two-point differential pressure ΔPX increases. Therefore, the operating rod 51 (valve body portion 52) moves downward, the opening degree of the communication passage 49 increases, and the crank pressure Pc tends to increase. For this reason, the swash plate 20 tilts in the inclination angle decreasing direction, and the refrigerant discharge capacity is decreased. If the refrigerant discharge capacity decreases, the refrigerant flow rate in the refrigerant circuit also decreases, and the two-point differential pressure ΔPX decreases.
[0059]
Further, for example, when the energization duty ratio to the coil 64 is increased and the upward electromagnetic force is increased, the operating rod 51 (valve body portion 52) is moved upward to reduce the opening degree of the communication passage 49 and the refrigerant discharge capacity. Is increased. Therefore, the refrigerant flow rate in the refrigerant circulation circuit increases, and the differential pressure ΔPX between the two points also increases.
[0060]
Conversely, when the duty ratio to the coil 64 is reduced to reduce the upward electromagnetic force, the operating rod 51 (valve body portion 52) is moved downward to increase the opening of the communication passage 49, and the refrigerant discharge capacity Decrease. Accordingly, the refrigerant flow rate in the refrigerant circulation circuit decreases, and the differential pressure ΔPX between the two points also decreases.
[0061]
That is, the control valve 43 responds to the fluctuation of the differential pressure ΔPX between the two points so as to maintain the control target (set differential pressure) of the differential pressure ΔPX between the two points determined by the duty ratio of energizing the coil 64. The operation rod 51 (valve body 52) is positioned internally autonomously. The set differential pressure can be changed from the outside by adjusting the duty ratio of energizing the coil 64.
[0062]
In the present embodiment, in the manufacturing process of the control valve 43, the solenoid-side housing 58 and the receiving cylinder 59 are fixed to each other by brazing in a state where the solenoid-side housing 58 is plated in a single state. ing. The brazing is performed in a state where the opening-side end portion of the housing cylinder 59 is inserted into the through hole 58A. That is, the plating process of the solenoid housing 58 is performed before the brazing process.
[0063]
In the present embodiment, nickel plating is employed in the plating process. Since the heat resistance temperature (transformation temperature; about 1400 ° C.) of the plating layer formed by the nickel plating process is higher than the maximum temperature (about 1120 ° C. in the present embodiment) in the brazing portion during the brazing process, The plated layer is not removed during the brazing process.
[0064]
In the present embodiment, the following effects can be obtained.
(1) The solenoid side housing 58 and the housing cylinder 59 are fixed to each other by brazing. According to this, the solenoid housing 58 and the housing cylinder 59 are more firmly fixed to each other by brazing, and the inside and the outside of the housing cylinder 59 are pressure-isolated from each other. Becomes easier. That is, it becomes easy to prevent leakage of the refrigerant from the inside of the storage cylinder 59 to the outside through the joint portion between the storage cylinder 59 and the solenoid housing 58.
[0065]
(2) The solenoid housing 58 is subjected to nickel plating. Therefore, the brazing process can be performed in a state where the solenoid-side housing 58 is plated. That is, since the transformation temperature of the plating layer formed by the nickel plating process is higher than the maximum temperature in the brazing part during the brazing process, the plating layer is not removed during the brazing process, The state in which the plated layer covers the surface of the solenoid-side housing 58 at the brazed portion can be satisfactorily maintained.
[0066]
Therefore, for example, as compared with the case where the solenoid housing and the housing cylinder fixed to each other by brazing are plated, the housing is performed without performing a masking process or the like for preventing the plating liquid from entering the housing cylinder. The formation of a plating layer on the inner surface of the cylinder can be prevented. As a result, it is possible to reduce the cost associated with the abolition of the masking process.
[0067]
Moreover, in this embodiment, since it is possible not to perform a plating process with respect to an accommodation cylinder, the situation where a plating solution enters in an accommodation cylinder can be avoided completely.
[0068]
(3) The housing cylinder 59 is made of stainless steel, and the solenoid side housing 58 is made of iron. That is, the housing cylinder 59 and the solenoid housing 58 are formed using stainless steel and iron, which are excellent in marketability, respectively. Therefore, it is relatively inexpensive and easy to make the housing cylinder and the solenoid side housing made of a non-magnetic material and a magnetic material, respectively.
[0069]
(4) The brazing is copper brazing using a copper brazing material. According to this, it is possible to realize brazing with relatively low cost and high mechanical strength.
(5) The solenoid-side housing 58 functions as a solenoid yoke that forms a magnetic path of electromagnetic force generated by the coil 64. According to this, it is possible to efficiently apply an electromagnetic force to the center post 60 and the plunger 62, and it is not necessary to provide a special solenoid yoke.
[0070]
(6) According to the control valve 43 of the present embodiment, the refrigerant discharge amount (refrigerant flow rate) per unit time of the compressor C, which greatly affects the load torque of the compressor C, is directly controlled from the outside. To get. Further, for example, the control for keeping the refrigerant flow rate below a predetermined amount can be performed with high accuracy and good responsiveness without using a refrigerant flow rate sensor or the like.
[0071]
(Second Embodiment)
This second embodiment is the same as the first embodiment except that the pressure-sensitive mechanism is omitted and the position of the valve body is changed only by control from the outside (drive circuit side). In other respects, the configuration is the same as that of the first embodiment. Accordingly, the same components as those in the first embodiment are denoted by the same reference numerals in the drawings, and redundant description is omitted.
[0072]
As shown in FIG. 3, the control valve 70 of the present embodiment communicates the valve chamber 71A, the relay chamber 71B, and the valve chamber 71A and the relay chamber 71B above the solenoid housing 58 (upward in the drawing). A valve-side housing 71 having a communication hole 71C is provided. The relay chamber 71B communicates with the plunger chamber 61 through a gap between the insertion hole 60A and the operating rod 51. That is, the inside of the storage cylinder 59 is in a state of communicating with the relay chamber 71B.
[0073]
The valve chamber 71 </ b> A communicates with the discharge chamber 28 via the upstream portion of the air supply passage 42. The relay chamber 71B communicates with the crank chamber 15 via the downstream portion of the air supply passage 42. That is, the valve chamber 71A, the relay chamber 71B, and the communication hole 71C constitute a part of the air supply passage 42 (gas passage).
[0074]
In the present embodiment, a spherical valve body 72 formed at the upper end of the operating rod 51 is disposed in the valve chamber 71A. The lower end side of the operating rod 51 inserted into the insertion hole 60A and the valve body 72 are connected by an intermediate portion 73 inserted through the communication hole 71C.
[0075]
In the present embodiment, when the coil 64 is not energized from the drive circuit (68), the actuating rod 51 is moved to the position shown in FIG. 3 (the lowest position) by the downward biasing force of the plunger biasing spring 63. It is arranged. In this state, the valve body 72 closes the opening on the upper side of the communication hole 71 </ b> C in the drawing so that the communication between the upstream portion and the downstream portion of the air supply passage 42 via the control valve 70 is blocked.
[0076]
Further, when the coil 64 is energized from the drive circuit (68), an upward biasing force is applied to the plunger 62 by the electromagnetic force generated in the coil 64 by this energization, and the plunger biasing spring 63 is applied. The plunger 62, that is, the valve body 72 is arranged at the most moved position against the urging force. In this state, the aforementioned closed state of the communication hole 71C by the valve body 72 is released, and the upstream portion and the downstream portion of the air supply passage 42 are communicated with each other.
[0077]
That is, in this embodiment, the control device (67) switches the communication state of the air supply passage 42 by the control valve 70 (switching whether or not to make the communication state) with respect to the drive circuit (68). Binary control is performed for this purpose.
[0078]
In the present embodiment, in addition to the same effects as the above (1) to (5), the following effects can be obtained.
(7) In this embodiment, the control valve 70 does not have the pressure-sensitive mechanism, and the control device (67) performs binary control. According to this, as compared with the first embodiment, it is possible to simplify the structure of the control valve, the control device, and the like.
[0079]
The embodiment is not limited to the above, and may be, for example, as follows.
In the above embodiment, the housing cylinder 59 is made of stainless steel, but is not limited to this. As long as it consists of a nonmagnetic material, it is good also as what consists of aluminum etc., for example.
[0080]
In the embodiment, the solenoid housing 58 is made of iron, but is not limited to this. As long as it is made of a magnetic material, it may be made of, for example, an Fe—Co alloy or an Fe—Ni alloy.
[0081]
In the above embodiment, the maximum temperature during brazing is about 1120 ° C., but is not limited thereto. It is sufficient that the temperature is lower than the transformation temperature of the nickel plating layer and does not adversely affect the brazing material.
[0082]
In the embodiment, brass brazing or silver brazing may be employed instead of copper brazing. Also, solder brazing may be employed.
The brazing process does not have to be a process immediately after the plating process.
[0083]
In the first embodiment, the control valve is configured to detect a pressure difference between two pressure monitoring points set in the refrigerant circulation circuit, but is not limited thereto. For example, the position of the valve body may be changed based on the pressure at one pressure monitoring point set in the refrigerant circulation circuit.
[0084]
The actuating rod 51 and the plunger 62 may be integrally formed. That is, the valve body (52, 72) and the plunger 62 may be integrally formed.
The solenoid housing 58 may not function as a solenoid yoke that forms a magnetic path of electromagnetic force generated by the coil 64. In this case, a solenoid yoke made of a member different from the solenoid-side housing 58 may be provided. Further, the solenoid yoke may not be provided.
[0085]
In the above embodiment, the control valve is used for adjusting the opening of the supply passage (gas passage), but the compressor is configured to change the crank pressure Pc by adjusting the opening of the extraction passage (gas passage). In addition, a control valve may be used for adjusting the opening degree of the extraction passage.
[0086]
○ The compressor C is replaced with a configuration in which the cam plate (swash plate 20) rotates integrally with the rotary shaft 16, and the cam plate is supported so as to be rotatable relative to the drive shaft. A (wobble) type compressor may be used.
[0087]
The compressor C is configured to be able to change the refrigerant discharge capacity per rotation of the rotary shaft 16 to almost zero, but may be configured to be unable to change to almost zero.
[0088]
○ Instead of a compressor equipped with a variable displacement piston compression mechanism that compresses refrigerant by reciprocating the piston, rotation of a variable displacement scroll compressor as disclosed in JP-A-11-324930 A mold compressor may be employed.
[0089]
Next, the technical idea that can be grasped from the embodiment will be described below.
(1) The electromagnetic valve for a variable displacement compressor according to any one of claims 1 to 4, wherein the brazing is a copper brazing using a copper brazing material.
[0090]
【The invention's effect】
As described in detail above, according to the first to fourth aspects of the present invention, in the electromagnetic valve of the variable displacement compressor, the plating layer of the solenoid housing is well maintained and the plating layer is formed in the housing member. Can be reliably avoided, and the cost can be reduced. Moreover, according to the invention of Claim 5, the electromagnetic valve of the capacity variable type compressor of Claims 1-4 can be manufactured.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an outline of a compressor according to a first embodiment.
FIG. 2 is a schematic cross-sectional view schematically showing the control valve.
FIG. 3 is a schematic cross-sectional view showing an outline of a control valve according to a second embodiment.
FIG. 4 is a cross-sectional view showing a conventional housing member and the like subjected to masking processing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 15 ... Crank chamber as a control pressure area | region, 41 ... Extraction passage as a gas passage, 42 ... Supply air passage as a gas passage, 43, 70 ... Control valve as a solenoid valve, 48, 71A ... Valve chamber, 52 ... Valve Valve body part as body, 54 ... Pressure-sensitive member, 58 ... Solenoid side housing as solenoid housing, 59 ... Housing cylinder as housing member, 62 ... Plunger as iron core, 64 ... Coil as solenoid, 72 ... Valve body C: Compressor as a variable capacity compressor.

Claims (5)

An electromagnetic valve used in a variable capacity compressor that constitutes a refrigerant circulation circuit and can change a refrigerant discharge capacity based on a pressure in a control pressure region,
A valve chamber provided to form a part of a gas passage for introducing a high-pressure refrigerant gas into the control pressure region or for discharging the refrigerant gas from the control pressure region;
A valve body provided in the valve chamber so as to be capable of changing a position, and capable of changing an opening of the gas passage by the position change in order to control the pressure in the control pressure region;
An iron core connected to the valve body so as to be integrally movable;
A housing member made of a non-magnetic material and capable of reciprocatingly moving the iron core;
A solenoid provided on the outside of the housing member and capable of generating an electromagnetic force acting on the iron core and involved in the positioning operation of the valve body;
A capacitor housing made of a magnetic material and capable of accommodating the solenoid, wherein the solenoid housing and the accommodating member are fixed to each other by brazing in a state in which the solenoid housing is nickel-plated. Solenoid valve for variable compressor. The solenoid valve of the variable displacement compressor according to claim 1, wherein the solenoid housing functions as a solenoid yoke that forms a magnetic path of electromagnetic force generated by the solenoid. The electromagnetic valve for a variable displacement compressor according to claim 1 or 2, wherein the housing member is made of stainless steel and the solenoid housing is made of iron. The pressure sensitive member is displaced based on the pressure difference between the two pressure monitoring points set in the refrigerant circulation circuit, so that the refrigerant discharge capacity is changed to cancel the pressure difference. The valve body is configured to change the position of the valve body, and a setting difference serving as a reference for the positioning operation of the valve body by the pressure-sensitive member by changing the force applied to the pressure-sensitive member by external control. The electromagnetic valve for a variable displacement compressor according to any one of claims 1 to 3, wherein the pressure can be changed. Used in a variable capacity compressor that constitutes the refrigerant circulation circuit and can change the refrigerant discharge capacity based on the pressure in the control pressure region,
A valve chamber provided to form a part of a gas passage for introducing a high-pressure refrigerant gas into the control pressure region or for discharging the refrigerant gas from the control pressure region;
A valve body provided in the valve chamber so as to be capable of changing a position, and capable of changing an opening of the gas passage by the position change in order to control the pressure in the control pressure region;
An iron core connected to the valve body so as to be integrally movable;
A housing member made of a non-magnetic material and capable of reciprocatingly moving the iron core;
A solenoid provided on the outside of the housing member and capable of generating an electromagnetic force acting on the iron core and involved in the positioning operation of the valve body;
A method of manufacturing a solenoid valve comprising a solenoid housing made of a magnetic material and capable of accommodating the solenoid,
A method of manufacturing an electromagnetic valve for a variable displacement compressor, wherein the solenoid housing and the housing member are fixed to each other by brazing in a step after the plating step of nickel plating the solenoid housing.

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