JP5866599B2 - solenoid valve - Google Patents

Description

  The present invention relates to a solenoid valve, and more particularly to a control valve suitable for mounting on a vehicle with high silence.

  In recent years, in vehicles equipped with an internal combustion engine, the combustion efficiency of the engine has improved, and it has become difficult for the cooling water used as a heat source to rise to the temperature required for heating. On the other hand, in a hybrid vehicle using both an internal combustion engine and an electric motor, the utilization rate of the internal combustion engine is low, so that it is more difficult to use such cooling water. There is no heat source by an internal combustion engine in an electric vehicle. For this reason, a heat pump type vehicle air conditioner that performs cycle operation using a refrigerant not only for cooling but also for heating to dehumidify and heat the vehicle interior has been proposed (see, for example, Patent Document 1).

  Such a vehicle air conditioner has a refrigeration cycle including a compressor, an outdoor heat exchanger, an evaporator, an indoor heat exchanger, etc., and the function of the outdoor heat exchanger is switched between heating operation and cooling operation. It is done. During the heating operation, the outdoor heat exchanger functions as an evaporator. In order to switch the cooling / heating function, a plurality of refrigerant circulation passages are provided in the refrigeration cycle, and various control valves are provided for controlling the flow of refrigerant in each refrigerant circulation passage. As such a control valve, an electromagnetic valve is often used so that the opening degree can be electrically adjusted from the outside.

Japanese Patent Laid-Open No. 9-240266

  By the way, since a hybrid vehicle, an electric vehicle, etc. use an electric motor as a traveling drive source, there is a problem that quietness is high and operation sound of on-vehicle equipment is more conspicuous than a vehicle using only an internal combustion engine as a drive source. For example, the solenoid valve opens and closes the valve unit when its valve body is driven by a solenoid, but the driver is uncomfortable because the level of the impact sound between the movable part and the fixed part of the solenoid is audible. there is a possibility. Although such a problem becomes prominent in an electric vehicle such as a hybrid vehicle or an electric vehicle, it may occur to some extent in a vehicle using only an internal combustion engine as a drive source. Moreover, it may occur in the same manner not only in a vehicle but also in an apparatus equipped with an electromagnetic valve.

  An object of the present invention is to realize a silencing mechanism for suppressing the generation of noise caused by the operation of a solenoid valve at low cost and to stably maintain the silencing function.

  In order to solve the above problems, an electromagnetic valve according to an aspect of the present invention is an electromagnetic valve configured by assembling a valve body and a solenoid. The solenoid includes a sleeve fixed to the valve body, and a sleeve. A fixed core, a plunger accommodated in the sleeve and axially opposed to the core, an electromagnetic coil wound around the sleeve to form a magnetic circuit with the plunger and the core, and the core relative to the plunger A biasing member that imparts a biasing force in a direction away from the sleeve, a locking portion that includes a reduced diameter portion provided on the opposite side of the core of the sleeve, and a flexible ring that is fitted to the side surface of the plunger Body, the solenoid is de-energized, and when the plunger is displaced away from the core, it is locked by the locking part, thereby restricting the displacement of the plunger in the axial direction. That comprise buffering and member. The buffer member is locked to the locking portion by setting the contact position between the locking portion and the buffer member so that the reaction force received by the buffer member from the locking portion has a component perpendicular to the axis of the plunger. It is configured to be deformed not only in the axial direction of the plunger but also inward in the radial direction.

  According to this aspect, when the plunger is displaced in a direction away from the core by turning off the solenoid, the buffer member fitted to the plunger is locked to the locking portion. When this buffer member is locked to the locking portion, it is deformed and absorbs an impact, thereby suppressing the occurrence of a collision sound. Further, since the reaction force received when the buffer member is displaced in the axial direction and hits the locking portion is configured to have a component in a direction perpendicular to the axial direction, the buffer member is also deformed inward in the radial direction. be able to. That is, if the reaction force acting on the buffer member is only the component in the axial direction, permanent deformation is likely to occur in the buffer member due to repeated compressive stress. On the other hand, in this mode, the reaction force acting on the buffer member has a radially inward component so that it can be partially released to the inside, thereby preventing permanent distortion and maintaining its life. can do. That is, according to this aspect, the silencing mechanism can be realized with a simple configuration in which the annular cushioning member is fitted to the plunger, and the silencing function can be stably maintained by extending the life of the cushioning member. .

  ADVANTAGE OF THE INVENTION According to this invention, while being able to implement | achieve the silencing mechanism for suppressing generation | occurrence | production of the noise accompanying the action | operation of a solenoid valve at low cost, the silencing function can be maintained stably.

It is sectional drawing showing the specific structure and operation | movement of the control valve which concerns on embodiment. It is sectional drawing showing the specific structure and operation | movement of the control valve which concerns on embodiment. It is a partial expanded sectional view showing the detail of the 1st silencer mechanism of a control valve. It is a partial expanded sectional view showing the detail of the 2nd silencer mechanism of a control valve. It is a partial expanded sectional view showing the structure of the silencing mechanism of the control valve which concerns on a modification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the present embodiment, the electromagnetic valve of the present invention is embodied as a control valve that is applied to an air conditioning apparatus for an electric vehicle. This vehicle air conditioner includes a refrigeration cycle in which a compressor, an indoor condenser, an outdoor heat exchanger, an evaporator, and an accumulator are connected by piping. BACKGROUND ART A vehicle air conditioner is configured as a heat pump type air conditioner that performs air conditioning in a vehicle interior using heat of the refrigerant in a process in which a refrigerant as a working fluid circulates while changing the state of the refrigeration cycle.

  The vehicle air conditioner is operated so as to switch a plurality of refrigerant circulation passages between a cooling operation and a heating operation. In this refrigeration cycle, the indoor condenser and the outdoor heat exchanger are configured to operate in parallel as a condenser, and the evaporator and the outdoor heat exchanger are configured to operate in parallel as an evaporator. Yes. The compressor is configured as an electric compressor that houses a motor and a compression mechanism in a housing. The indoor condenser is provided in the passenger compartment and functions as an auxiliary condenser that dissipates the refrigerant separately from the outdoor heat exchanger. The outdoor heat exchanger is disposed outside the vehicle compartment and functions as an outdoor condenser that dissipates the refrigerant that passes through the interior during the cooling operation, and functions as an outdoor evaporator that evaporates the refrigerant that passes through the interior during the heating operation. An evaporator is arrange | positioned in a vehicle interior and functions as an indoor evaporator which evaporates the refrigerant | coolant which passes the inside. The accumulator is a device that stores the refrigerant sent from the evaporator by gas-liquid separation, and has a liquid phase part and a gas phase part, and leads the refrigerant in the gas phase part to the compressor.

  And the control valve of this embodiment is provided in the downstream of an evaporator, and functions as an evaporation pressure control valve which controls the evaporation pressure of the refrigerant | coolant in the evaporator. That is, the control valve of the present embodiment is provided on each of the downstream side of the indoor evaporator and the downstream side of the outdoor evaporator, and the opening degree of the downstream passage of the evaporator is adjusted by adjusting the opening degree of the valve part by supplying current. To adjust the evaporation pressure of the evaporator. In the present embodiment, an open / close valve (on / off valve) that opens and closes depending on whether or not energization is used as the control valve, and the opening degree is adjusted by adjusting the valve opening time per certain time. In a modification, you may comprise as a proportional valve or differential pressure valve which can adjust the opening area itself of a valve part.

Next, a specific configuration of the control valve of the present embodiment will be described. 1 and 2 are cross-sectional views showing a specific configuration and operation of the control valve according to the embodiment.
As shown in FIG. 1, the control valve 101 is configured by assembling a valve main body 102 that houses a valve mechanism therein and a solenoid 104 that drives the valve mechanism. An inlet port 110 connected to the upstream passage is provided on one side of the body 105 in the valve body 102, and a lead-out port 112 connected to the downstream passage is provided on the other side. A valve hole 114 is provided in the internal passage connecting the introduction port 110 and the outlet port 112, and a valve seat 116 is formed at the downstream opening end thereof.

  A bottomed cylindrical valve body 118 is arranged in the pressure chamber 117 on the downstream side of the valve hole 114. A circular boss-shaped guide portion 119 extends downward from the solenoid 104 toward the pressure chamber 117, and a valve body 118 is slidably fitted on the guide portion 119. That is, the valve body 118 is stably supported while being guided by the guide portion 119. A spring 120 that biases the valve body 118 in the valve opening direction is interposed between the valve body 118 and the body 105.

  On the other hand, the solenoid 104 is attached so as to seal the upper end opening of the body 105. The solenoid 104 has a core 130 connected so as to seal the body 105, a bottomed cylindrical sleeve 132 that is accommodated so as to fix an upper portion of the core 130, and an axially opposed core 130 within the sleeve 132. It includes a disposed plunger 134, a bobbin 136 extrapolated to the sleeve 132 and the core 130, and an electromagnetic coil 138 wound around the bobbin 136. A resin mold is formed so as to cover the electromagnetic coil 138 from the outside. An annular plate 139 made of a magnetic material is provided on the upper surface of the bobbin 136. The annular plate 139 functions as a yoke that forms a magnetic circuit when the solenoid 104 is energized.

  A through hole 131 is provided in the core 130 along the axis thereof, and a long operating rod 142 passes through the through hole 131. The operating rod 142 has an upper end in contact with the lower surface of the plunger 134 and a lower end in contact with the bottom of the valve body 118. That is, the operating rod 142 is disposed so as to be sandwiched between the plunger 134 and the valve body 118 without being fixed, and operates integrally therewith. A back pressure chamber 146 is formed between the bottom of the sleeve 132 and the plunger 134. The plunger 134 has a stepped columnar shape, a communication groove 143 parallel to the axis is formed at a predetermined position on the outer peripheral surface, and a communication path for communicating the communication groove 143 and the back pressure chamber 146 in the upper half. 144 is formed. With such a configuration, the communication state between the space between the core 130 and the plunger 134 and the back pressure chamber 146 is maintained.

  The upper end portion of the sleeve 132 has a reduced inner diameter, and a locking portion 148 is constituted by a step portion formed in the reduced diameter portion. The locking portion 148 regulates the upward displacement of the plunger 134 in the axial direction. On the other hand, the outer diameter of the upper end portion of the plunger 134 is reduced, and a concave fitting groove 150 is provided around the reduced diameter portion. An O-ring 152 (functioning as a “buffer member”) is fitted into the fitting groove 150. When the solenoid 104 is not energized, the O-ring 152 and the locking portion 148 constitute a silencer mechanism, the details of which will be described later. The fitting groove 150 is formed in the plunger 134 so as to be positioned above the annular plate 139 in a state where the plunger 134 is closest to the core 130 when the solenoid 104 is energized (see FIG. 2). As a result, even when the solenoid 104 is energized, the O-ring 152 is positioned outside the yoke (above the annular plate 139), so that loss in magnetic characteristics is unlikely to occur. In the modification, the O-ring 152 and the yoke may partially overlap in a range where the loss of magnetic characteristics is equal to or less than a predetermined reference value. For example, when the plunger 134 is closest to the core 130, the O-ring 152 and the annular plate 139 partially overlap in the radial direction, but the O-ring 152 is interposed between the annular plate 139 and the plunger 134. It is good also as a structure which can ensure a magnetic path without this.

  Further, the above-described guide portion 119 extends downward from the center of the lower surface of the core 130, and the valve body 118 is slidably fitted on the guide portion 119. With such a configuration, the back pressure chamber 154 is defined between the valve body 118 and the core 130. The back pressure chamber 154 communicates with the back pressure chamber 146 via a clearance between the core 130 and the operating rod 142, a space between the core 130 and the plunger 134, a communication groove 143, and a communication passage 144. A communication hole 122 (functioning as a “leak passage”) that connects the back pressure chamber 154 and the upstream pressure chamber is formed at the bottom of the valve body 118. Therefore, the upstream pressure Pin is filled in the back pressure chamber 154 when the control valve 101 as shown in FIG. 2 is controlled.

  The control valve 101 configured as described above has no suction force between the core 130 and the plunger 134 when the solenoid 104 is turned off (non-energized state) as shown in FIG. The body 118 is urged in the valve opening direction by the spring 120 and is fully opened. On the other hand, as shown in FIG. 2, when the solenoid 104 is turned on (energized state), a suction force acts between the core 130 and the plunger 134. 118. As a result, the valve body 118 operates in the valve closing direction.

  In this embodiment, the differential pressure (Pin−Pout) between the upstream pressure Pin and the downstream pressure Pout is opened in the valve body 118 by introducing the upstream pressure Pin into the back pressure chamber 154 through the communication hole 122. The area (AB) acting in the valve direction is made smaller than the cross-sectional area A of the valve hole 114. Thereby, the influence of the pressure of the refrigerant acting on the valve body 118 is largely canceled, and the valve body 118 can be driven in the valve closing direction with a relatively small solenoid force. Further, in the present embodiment, the communication hole 122 is made sufficiently small so that a damper function that relaxes the operation of the valve body 118 by introducing and discharging the refrigerant into the back pressure chamber 154 via the communication hole 122 is exhibited. Become. In the present embodiment, by adjusting the time ratio between the energized state (ON) and the non-energized state (OFF) of the solenoid 104 of the control valve 101, that is, the ON / OFF duty ratio, The average differential pressure as a value can be controlled to an appropriate value.

Next, the configuration and operation of the main part of the present embodiment will be described in detail.
FIG. 3 is a partially enlarged cross-sectional view showing details of the first silencing mechanism of the control valve. (A) shows the reaction force acting on the O-ring 152 when the solenoid 104 is turned off, and (B) shows the details of the shape and arrangement of the O-ring 152.

  When the solenoid 104 is switched from the energized state to the non-energized state (from on to off), the plunger 134 is displaced upward in the axial direction, but the locking portion 148 locks the O-ring 152 to restrict the displacement. The O-ring 152 functions as a buffer member, and is deformed when the O-ring 152 is locked to the locking portion 148 so as to absorb an impact, so that the collision sound is higher than when the plunger 134 is locked directly to the locking portion 148. Is suppressed.

  Here, assuming a configuration in which the O-ring 152 is compressed only in the axial direction, a compressive stress in a certain direction repeatedly acts on the O-ring 152 when the solenoid 104 is turned on / off. As a result, permanent deformation easily occurs in the O-ring 152 at an early stage, and the impact absorbing effect is reduced. Therefore, in the present embodiment, by devising the positional relationship between the O-ring 152 and the locking portion 148 and the shape of the O-ring 152, a configuration in which such permanent distortion hardly occurs is realized.

  That is, as shown in FIG. 3A, the upper end portion of the sleeve 132 is reduced in diameter, and is configured to abut on the O-ring 152 at the tapered surface of the reduced diameter portion. As a result, when the O-ring 152 is locked to the locking portion 148, a diagonal downward vertical drag (see a thick arrow) acts on the O-ring 152 as a reaction force from the locking portion 148. That is, the O-ring 152 receives not only the component in the axial direction of the plunger 134 but also the component in the direction perpendicular to the axial line as a reaction force (see thin arrows). In addition, since the component in the perpendicular direction acts inward in the radial direction, the O-ring 152 can be released to the inside, and uneven deformation in the axial direction can be prevented or suppressed.

  In order to apply such a reaction force, as shown in FIG. 3B, the clearance between the inner peripheral surface of the O-ring 152 and the outer peripheral surface of the plunger 134 is a, and the engagement portion 148 and the O-ring 152 When the radial distance between the contact P and the cross-sectional center O of the O-ring 152 is b and the radius of the cross-section of the O-ring 152 is r, the relationship of a <b and a <rb is satisfied. It is composed. Here, the clearance a is an average value of the shortest distance between the bottom surface of the fitting groove 150 and the inner peripheral surface of the O-ring 152.

  That is, by setting a <b, even if the O-ring 152 is displaced in the radial direction, the contact point P can be positioned outside the center O of the cross section. An inward force can be applied. Further, by setting a <r−b, the contact state with the locking portion 148 can be maintained over the entire circumference of the O-ring 152. That is, permanent distortion can be made difficult to occur by partially releasing the O-ring 152 to the inside, and the silencing function can be stably maintained over a long period of time.

  FIG. 4 is a cross-sectional view showing details of the second silencing mechanism of the control valve. (A)-(C) show the configuration and operation of the facing portion between the core 130 and the plunger 134, and (D) shows the silencing effect due to the operation. For convenience of explanation, the configuration of the facing portion in FIGS. 4A to 4C is slightly exaggerated from that shown in FIGS. 4A shows the position of the plunger 134 when the solenoid 104 is turned off (also referred to as “valve closing position”), and FIG. 4C shows the position of the plunger 134 when the solenoid 104 is turned on. (Also referred to as “fully open position”). FIG. 4B shows a state in which the plunger 134 reaches the inflection point (g point) of the magnetic attractive force in the valve closing process. The horizontal axis of FIG. 4D illustrates the magnetic gap G (mm) between the core 130 and the plunger 134, and the vertical axis indicates the attractive force of the solenoid 104 and the biasing force (load: kg weight) of the spring 120. . The dotted line in the figure shows the suction force and the spring load before the noise reduction countermeasure, and the solid line in the figure shows the suction force and the spring load after the noise reduction countermeasure.

  In the present embodiment, an attractive force adjusting structure that reduces an increase in solenoid force when the magnetic gap G becomes a set value or less is provided in the facing portion between the plunger 134 and the core 130. Thereby, the load difference between the solenoid force in the valve closing direction when the valve body 118 is in the valve closing position and the biasing force in the valve opening direction by the spring 120 is reduced, so that the valve body 118 is seated on the valve seat 116. The collision energy is reduced and the collision sound is reduced.

  That is, as shown in FIG. 4A, the lower portion of the plunger 134 has a tapered shape with the outer diameter decreasing downward, and a convex portion 160 having a constant cross section is formed at the center of the lower end portion. On the other hand, the upper part of the core 130 is substantially complementary to the lower part of the plunger 134. That is, the upper portion of the core 130 has a tapered shape with an inner diameter increasing upward, and a concave portion 162 having a constant cross section is formed at the center of the base end portion. The convex portion 160 can be inserted into the concave portion 162, and the “suction force adjusting structure” is realized by both of them. FIG. 4B shows a state in which the tip of the convex portion 160 reaches the entrance of the concave portion 162, and FIG. 4C shows a state in which the convex portion 160 is inserted into the concave portion 162.

  That is, the attractive force of the solenoid 104 changes according to the magnetic gap G, which is the distance between the opposed surfaces of the core 130 and the plunger 134, and increases as the magnetic gap G becomes smaller. As shown in FIG. When the portion 160 is inserted into the concave portion 162, the magnetic field lines leak in the radial direction at the overlap portion, and the attraction force is hardly increased. In the present embodiment, the collision when the valve body 118 is seated on the valve seat 116 when the valve is closed by adjusting the load difference between the suction force of the solenoid 104 and the urging force of the spring 120 using such properties. Reduce sound.

  Specifically, as shown in FIG. 4 (D), the insertion structure (spool structure) by the convex portion 160 and the concave portion 162 is not provided before the noise reduction countermeasure, and as a result, as the magnetic gap G becomes smaller by energization. The attraction force characteristic increases abruptly. On the other hand, since the spring constant of the spring 120 is not so large, the load difference between the suction force and the urging force at the valve closing position is relatively large at about 1 kg weight. As a result, the large load difference becomes a collision energy when the valve body 118 is seated on the valve seat 116, and a large collision sound is generated.

  Therefore, in the present embodiment, adjustment is made so that the load difference between the suction force and the urging force when the valve is closed is reduced. First, a spring 120 having a larger spring constant is employed. That is, the spring constant is set so that the spring load can be increased within a range not exceeding the magnetic attraction force assumed at the valve closing position (point c). Then, while maintaining the magnetomotive force in the fully open position when the solenoid 104 is switched from OFF to ON (point e), the attractive force is reduced to the extent that the spring load does not fall below the valve load position (point a). (→ b point), the length of the convex portion 160 is adjusted.

  Specifically, a magnetic gap G0 that obtains an attractive force equivalent to the spring load (point c) at the valve closing position of the spring 120 is acquired, and the tip of the convex portion 160 approaches the point g at the magnetic gap G0. Thus, the length of the convex portion 160 is set. That is, the setting is made as shown in FIG. A predetermined error (for example, ± 0.5 mm) may be allowed. As a result, while the convex portion 160 is inserted through the concave portion 162 beyond the point g, that is, while the magnetic gap G is smaller than G0, the magnetic attraction force rises gradually, and as a result, the attractive force at the valve closing position is reduced. (Point b) can be made closer to the spring load (point c). That is, by reducing the load difference between the magnetic attractive force and the spring load, it is possible to reduce the collision energy, and it is possible to reduce the collision noise when the valve is closed. In the present embodiment, a good silencing effect can be obtained by setting the spring load (point c) at the valve closing position to be at least 50% or more (preferably 80% or more) of the magnetic attractive force (point b). I am doing so.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments, and various modifications can be made within the scope of the technical idea of the present invention. Nor.

  FIG. 5 is a partially enlarged cross-sectional view showing a configuration of a silencer mechanism for a control valve according to a modification. (A) shows the reaction force acting on the O-ring 152 when the solenoid 104 is turned off, and (B) shows the details of the arrangement configuration of the O-ring 152 and the locking portion 248.

  In this modification, the locking portion 148 is not a taper surface but an edge portion between the main body of the sleeve 232 and the small diameter portion. That is, as shown in FIG. 5A, the upper end portion of the sleeve 232 is reduced in a convex shape, and the edge portion formed on the inner peripheral surface of the reduced diameter portion contacts the O-ring 152. It is configured to touch. Also in this modified example, as shown in FIG. 5B, the clearance between the inner peripheral surface of the O-ring 152 and the outer peripheral surface of the plunger 134 is a, the contact point P between the locking portion 248 and the O-ring 152, and the O-ring. When the radial distance from the cross-sectional center O of 152 is b and the radius of the cross-section of the O-ring 152 is r, the relationship of a <b and a <rb is satisfied. Accordingly, the contact state with the locking portion 148 can be maintained over the entire circumference of the O-ring 152, and a radially inward force can be applied to the O-ring 152. As a result, the O-ring 152 can be partially escaped inward so that the O-ring 152 is less likely to be permanently deformed, so that the silencing function can be stably maintained over a relatively long period of time.

  In the above embodiment, an example in which an O-ring is used as a buffer member fitted to the plunger 134 has been described. In the modification, an annular body made of an elastic member (for example, rubber) having a circular cross section may be employed. Further, the cross-sectional shape of the buffer member may be an elliptical shape instead of a perfect circle, or may be a polygonal shape. In this case, however, the clearance between the inner peripheral surface of the buffer member and the outer peripheral surface of the plunger is a, the distance in the radial direction of the plunger between the contact point between the engaging portion and the buffer member and the center of the cross section of the buffer member is b, When the radius of the cross section of the member is r, the relationship of a <b and a <rb is satisfied.

  In the above embodiment, the configuration in which the locking portion 148 is integrally formed in the vicinity of the bottom portion of the bottomed cylindrical sleeve 132 is illustrated. In the modified example, the bottom portion of the sleeve 132 may be sealed with a separate member, and a locking portion may be provided on the separate member. That is, the reduced diameter portion may be configured by a nonmagnetic separate member (for example, a resin member) on the opposite side to the core of the sleeve, and the reduced diameter portion may be used as the locking portion.

  In the above embodiment, a configuration is provided in which both the first silencing mechanism (see FIG. 3) for reducing the collision noise of the plunger 134 and the second silencing mechanism (see FIG. 4) for reducing the collision noise of the valve body 118 are provided. Indicated. In the modified example, any one of the mute mechanisms may be provided.

  In the above embodiment, the control valve 101 is provided on the downstream side of both the indoor evaporator and the outdoor evaporator. However, the control valve 101 may be provided only on the downstream side of one of the evaporators. For example, the control valve 101 may be provided on the downstream side of the indoor evaporator, and the control valve 101 may not be provided on the downstream side of the outdoor heat exchanger (when acting as an outdoor evaporator).

  In the above embodiment, an example in which the electromagnetic valve of the present invention is applied to an air conditioning apparatus for an electric vehicle has been shown. However, the present invention also applies to an automobile equipped with an internal combustion engine, or a hybrid automobile air conditioning apparatus equipped with an internal combustion engine and an electric motor. Needless to say, it is applicable. In the above-described embodiment, an example in which an electric compressor is employed as the compressor has been described. However, a variable capacity compressor that performs variable capacity by utilizing the rotation of the engine can also be employed. Furthermore, it is needless to say that the present invention is applicable not only to a vehicle but also to an apparatus equipped with an electromagnetic valve.

  101 Control valve, 102 Valve body, 104 Solenoid, 105 Body, 110 Inlet port, 112 Outlet port, 114 Valve hole, 116 Valve seat, 118 Valve body, 120 Spring, 122 Communication hole, 130 Core, 132 Sleeve, 134 Plunger, 138 Electromagnetic coil, 142 Acting rod, 148 Locking part, 152 O-ring, 154 Back pressure chamber, 160 Convex part, 162 Concave part, 232 Sleeve, 248 Locking part.

Claims (8)

In a solenoid valve constructed by assembling a valve body and a solenoid,
The solenoid is
A sleeve fixed to the valve body;
A core fixed to the sleeve;
A plunger accommodated in the sleeve and disposed opposite to the core in the axial direction;
An electromagnetic coil wound around the sleeve to form a magnetic circuit with the plunger and the core;
A biasing member that applies a biasing force in a direction away from the core to the plunger;
A locking portion comprising a reduced diameter portion provided on the opposite side of the sleeve from the core;
It is made of a flexible annular body that is fitted to the side surface of the plunger, and when the solenoid is de-energized and the plunger is displaced in a direction away from the core, the plunger is locked to the locking portion. A buffer member for restricting displacement in the axial direction of the plunger;
Including
The abutting position of the locking portion and the buffer member is set so that the reaction force received by the buffer member from the locking portion has a component perpendicular to the axis of the plunger, whereby the buffer member is An electromagnetic valve configured to be deformed not only in the axial direction of the plunger but also inward in the radial direction of the annular body when locked by the locking portion. The buffer member is made of an annular body having a circular cross section,
The clearance between the inner peripheral surface of the buffer member and the outer peripheral surface of the plunger is a, and the radial distance of the annular body between the contact point between the locking portion and the buffer member and the cross-sectional center of the buffer member is b. 2. The solenoid valve according to claim 1, wherein the relationship of a <b and a <rb is satisfied when r is a radius of a cross section of the buffer member.   The electromagnetic valve according to claim 2, wherein the buffer member is an O-ring.   The shock-absorbing member is fitted to an end of the plunger opposite to the core, and is provided so as to be positioned outside a yoke constituting the magnetic circuit when the solenoid is energized. Item 4. The solenoid valve according to any one of Items 1 to 3. The valve body includes a body provided with a working fluid introduction port and a lead-out port, and a valve body that opens and closes a valve portion in contact with and away from a valve hole provided in a passage connecting the introduction port and the lead-out port. Including
The plunger is provided on the opposite side to the valve body with respect to the core, and transmits a solenoid force in a valve closing direction to the valve body through an operation rod penetrating the core.
The urging member includes a spring interposed between the body and the valve body, and urges the valve body in a valve opening direction so that the plunger moves from the core to the plunger via the operating rod. Applying a biasing force in the direction of separation,
The valve body, the operation rod, and the plunger are provided so as to be integrally displaceable by contacting the plunger on one end side thereof and contacting the valve body on the other end side. The electromagnetic valve according to claim 1, wherein the electromagnetic valve is characterized in that: At the facing portion between the plunger and the core, there is an attractive force adjustment structure that alleviates an increase in the solenoid force when a magnetic gap becomes a predetermined value or less,
The load difference between the solenoid force in the valve closing direction when the valve body is in the valve closing position and the biasing force in the valve opening direction by the spring is configured to be smaller than in the case without the suction force adjusting structure. The solenoid valve according to claim 5.   The said spring has the spring characteristic which generate | occur | produces the urging | biasing force 50% or more of the solenoid force, when the said valve body will be in a valve closing position by electricity supply to the said solenoid. solenoid valve. The valve body is supported by the body or the core so as to be slidable in the axial direction, and forms a back pressure chamber between the valve body and the leak, while communicating the valve hole and the back pressure chamber. Has a passage,
The damper that relaxes the operation of the valve body while at least part of the influence of the pressure of the working fluid acting on the valve body is canceled by the introduction and withdrawal of the working fluid to and from the back pressure chamber via the leak passage. The solenoid valve according to claim 5, wherein the solenoid valve is configured to exhibit a function.

Images