Solenoid valve

A solenoid valve having a movable member being moved by an electromagnetic attraction of a solenoid section in a valve chest between the solenoid section. A valve seat opposed thereto and a valve body provided an the movable member is abutted against or separated from the valve seat to close or open a valve port or ports. The movable member is supported in the valve chest through a support member or members for regulating a displacement of the movable member in a direction perpendicular to the moving direction of the movable member. The valve body may be fixed to or movable from the movable member. The movable member is formed with a through-hole for receiving the valve body, which extends in the moving direction thereof. The valve body, formed of an elastic material, is disposed in the through-hole and a surface of the valve body, which is opposed to the solenoid section forms a surface of the movable member, which is abutted against the solenoid section. There are provided a first valve port formed on the solenoid section side and a second valve port opposed thereto. The valve body need not be fixed to the movable member so that the valve body is moved toward the second valve seat without being influenced by the movement of the movable member toward the second valve seat. One surface of the valve body is abutted against or separated from a first valve seat of the first valve port to close or open the first valve port and the other surface of the valve body is abutted against or separated from a second valve seat of the second valve port to close or open the second valve port.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a solenoid valve for use in ON-OFF operation and 
switching of a flow of fluid such as air. 
2. Related Art Statement 
A known solenoid valve of the type described, includes a solenoid section 
provided with a solenoid coil and a fixed iron core; a valve seat opposed 
to the solenoid section in a valve chest; a valve port of this valve seat; 
a movable member with a valve body, which is positioned between the 
solenoid section and the valve seat in the valve chest that is moved by 
magnetic action; and a resilient member such as a spring for biasing this 
movable member from the underside of the solenoid section to the valve 
seat. During non-excitation of the solenoid section, the movable member is 
urged against the valve seat by the biasing force of the resilient member 
or the like to close the valve port. During excitation of the solenoid 
section, the movable member is separated from the valve seat by the 
magnetic attracting action of the solenoid section against the biasing 
force of the resilient member or the like and attracted to the fixed iron 
core, thereby opening the valve port. The movable member is reciprocated 
between the solenoid section and the valve seat in the valve chest, 
whereby the valve port is ON-OFF operated, so that the flow of the fluid 
can be switch controlled. 
The movable member is reciprocated between the solenoid section and the 
valve seat in the valve chest due to the magnetic attraction of the 
solenoid section, for ON-OFF operation of the valve port. However, since 
the displacement of the movable member is not regulated in a direction 
perpendicular to the reciprocatory movement the outer peripheral portion 
of the movable member comes into contact with or slides on the inner wall 
surface of the valve chest. A resulting disadvantage is when the outer 
peripheral portion of this movable member comes into contact with or 
slides on the inner wall surface of the valve chest, whereby the contact 
portion and the sliding portion are worn, the dust or debris caused by 
wear moves to a fluidal circuit connected to the solenoid valve, to 
thereby hinder other components. 
A further disadvantage is that, due to the wear of the above-described 
contact portion and sliding portion, smooth operation of the movable 
member is hindered. 
In the known solenoid valve, when the solenoid section is deenergized, the 
movable member which has been in contact with the fixed iron core is moved 
to the side of the valve seat by the biasing force of a resilient member 
such as the spring or the like, whereby the valve body abuts against the 
valve seat. As the valve body is fixed to the movable member, in addition 
to the biasing force of the resilient member such as a spring or the like, 
an inertial force of the valve body and the inertial force of the movable 
member, which is substantially larger than the former inertial force, are 
directly applied to the contact portion between the valve body and the 
valve seat. A resulting disadvantages due to the biasing force of the 
resilient member such as a spring or the like, and the inertial forces of 
the movable member and the valve body which are directly applied to the 
contact portion between the valve body and the valve seat, is that the 
contact portion between the valve body and the valve seat is worn and 
damaged, to thereby impair the function of the solenoid valve. 
Also, in the known solenoid valve, when the movable member is brought into 
abutting contact with the fixed iron core of the solenoid section due to 
the magnetic attracting action of the solenoid section, by percussions 
occurring between the metallic abutting surfaces of both members, the 
abutting surfaces of both members are worn, so that the solenoid valve 
cannot be used for a long period of time and with high frequency. 
As a means for preventing the foregoing disadvantages a shock-absorbing 
member formed of resilient material is provided on either the abutting 
surface of the movable member or the abutting surface of the fixed iron 
core of the solenoid section. However, the provision of a shock-absorbing 
member makes the construction complicated. Furthermore, when the 
shock-absorbing member is provided on the movable member, if a coupling 
groove is formed in the movable member and the shock-absorbing member is 
to be coupled into this coupling groove, then, the thickness of the 
shock-absorbing member is restricted by the depth of the coupling groove, 
i.e., the thickness of the movable member. Due to the small thickness, 
only a shock-absorbing member of low resiliency can be provided. 
Accordingly, a satisfactory shock-absorbing effect cannot be obtained. 
However, if the thickness of the movable member is increased to deepen the 
coupling groove, whereby a shock-absorbing member having a large thickness 
can be provided, then, the inertial force of the movable member during its 
movement is increased by as much as the thickness of the movable member is 
increased. Therefore the impact forces of the movable member, which is 
aplied to the fixed iron core and the valve seat, is increased such that a 
satisfactory shock-absorbing effect still cannot be obtained. 
Furthermore, the valve body of the above-described solenoid valve is 
constructed such that the valve body is moved in association with the 
movement of the movable member at all times. The inertial force of the 
movable member is larger in value than the inertial force of the valve 
body and the inertial force of the valve body itself is applied to the 
valve body to abut the valve body against the valve seat. A resulting 
disadvantage is that the valve body and/or the valve seat wears and is 
likely to become damaged. 
Further, in the above-described solenoid valve, when a plurality of valve 
bodies, one for ON-OFF operation of a first valve port and the other for 
ON-OFF operation of a second valve port, are provided in the movable 
member, these valve bodies are supported by shock-absorbing springs in the 
movable member. A disadvantage of this arrangement is that the movable 
member becomes large in size and complicated in construction. 
SUMMARY OF THE INVENTION 
The present invention has been developed to obviate the above-described 
disadvantages and has as one of its objects the provision of a solenoid 
valve constructed such that the outer peripheral portion of the movable 
member does not come into contact with or slide on the inner wall surface 
of the valve chest. 
Another object of the present invention is to provide a solenoid valve 
constructed such that the inertial force of the movable member is not 
directly applied to a contact portion between the valve body and the valve 
seat, thus providing higher durability. 
A further object of the present invention is to provide a solenoid valve 
construction wherein absorb to absorb the shock given by the movable 
member to the solenoid section can be simplified, and yet, a satisfactory 
shock-absorbing effect can be obtained, abutting surfaces of the movable 
member and the solenoid section can be satisfactorily prevented from being 
worn, thereby improving the durability thereof. 
A still further object of the present invention is to provide a solenoid 
valve, wherein operating reliability and durability can be improved, and 
compactness and simplification of the construction can be attained. 
To achieve the above-described objects, the present invention contemplates 
a solenoid valve constructed such that the movable member with a valve 
body, which moves between the solenoid section and the valve seat in the 
valve chest, is supported in the valve chest by a support member which 
controls displacement of the movable member in a direction perpendicular 
to the direction of movement of the movable member. 
In the solenoid valve the movable member with the valve body, for ON-OFF 
operation of the valve port is supported in the valve chest by the support 
member which controls displacement of the movable member in the direction 
perpendicular to the direction of movement. Thus the movable member is 
prevented from being displaced in the direction perpendicular to its 
direction of movement. Accordingly, the outer peripheral portion of the 
movable member does not come into contact with or slide on the inner wall 
surface of the valve chest due to the above-described displacement of the 
movable member. Thus the movement of the movable member can be performed 
smoothly and reliably. 
In another embodiment of the solenoid value according to the present 
invention, the valve body is not fixed to the movable member. The valve 
body is thus enabled to remove toward the solenoid section in association 
with the movement of the movable member toward the solenoid section and 
moves toward the valve seat without being influenced by movement of the 
movable member toward the valve seat. 
When the movable member of the solenoid valve moves toward the solenoid 
section, the valve body also moves toward the solenoid section in 
association with the movement of the movable member toward the solenoid 
section. However, when the movable member moves toward the valve seat, the 
valve body moves toward the valve seat uninfluenced by the movement of the 
movable member toward the valve seat. Thus the valve body is moved toward 
the valve seat and is urged thereagainst without being directly subject to 
the inertial force of the movable member due to its movement toward the 
valve seat. Accordingly, the inertial force of the movable member is not 
directly applied to the contact portion between the valve body and the 
valve seat. Thus the contact portions of the valve body and the valve seat 
can be prevented from being worn or damaged by inertial force of the 
movable member. 
In another embodiment of the solenoid valve according to the present 
invention, the solenoid valve includes a movable member, which is 
attracted by the magnetic attracting action of the solenoid section, to 
thereby move between the solenoid section and the valve seat opposed 
thereto in the valve chest. A through-hole is formed in the movable member 
in the direction of movement for receiving the valve body. The valve body 
is formed of an elastic material and is received in the through-hole. The 
surface of the valve body, which is opposed to the solenoid section, is 
abutted against the solenoid section when the movable member is attracted 
by the solenoid section. 
When the movable member is attracted by the magnetic attracting action of 
the solenoid section to move toward the solenoid section, the surface of 
the valve body, which is opposed to the solenoid section, abuts against 
the solenoid section. The impact shock at the time of abutting is relieved 
by the elastic force of the valve body because the valve body, which has 
been abutted against the solenoid section is made of elastic material. 
Thus a shock-absorbing effect of the movable member to the solenoid 
section can be obtained, so that the abutted surfaces between the movable 
member and the solenoid section can be prevented from being worn. 
In a still further embodiment of the present invention, the solenoid valve 
includes a first valve port on the underside of the solenoid section, a 
second valve port opposed to the first valve port. A movable member with a 
valve body is moved between the first and second valve ports by magnetic 
attraction of the solenoid section. The movable member is supported by a 
support member which controls displacement in a direction perpendicular to 
the moving direction. The single valve body is not fixed to the movable 
member so that movement of the valve body toward the second valve port is 
uninfluenced by movement of the movable member toward the second valve 
port. One surface of the valve body is adapted to abut against or be 
separated from a first valve seat of the first valve port to thereby close 
or open the first valve port. The other surface of the valve body is 
adapted to abut against or be separated from a second valve seat of the 
second valve port to thereby close or open the second valve port. 
The movable member is prevented from being displaced in the direction 
perpendicular to the moving direction by the support provided by the 
support member. Thus, the outer peripheral portion of the movable member 
does not come into contact with or slide on the inner wall surface of the 
valve chest. Consequently the outer peripheral portion of the movable 
member can be prevented from being worn, and the movable member can be 
operated smoothly and reliably. 
Furthermore, the valve body is not fixed to the movable member so that 
movement of the valve body toward the second valve port is uninfluenced by 
movement of the movable member toward the second valve port. When the 
movable member moves toward the second valve port, the valve body moves 
toward the second valve port and is abutted against the second valve seat 
without being subject to the inertial force of the movable member. Thus 
the valve body and the second valve seat can be effectively prevented from 
being worn or damaged. 
Further, the single valve body is provided on the movable member, whereby 
both the first and second valve ports can be opened or closed by the 
single valve body. Thus the solenoid valve can be rendered compact in size 
and simplified in construction. 
Additionally, the aforesaid and other objects, and advantages of the 
present invention will become apparent more fully from the following 
detailed description in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to the drawings, one embodiment of the solenoid valve is 
generally indicated by the reference number 1 in FIG. 1. The solenoid 
valve 1 includes a solenoid section 2, a valve box 3 connected to the 
solenoid section 2 and a movable member 4 with a valve body 4a. The 
solenoid section 2 is constituted by a bobbin 5 wound with a solenoid coil 
5a, a columnar fixed iron core 6 and a protective cap 7 covering the outer 
periphery of this fixed iron core 6. The center of the columnar fixed iron 
core 6 is provided in the undersurface with a cylindrical groove 6a for 
receiving a resilient member, and an annular groove 6b for receiving the 
bobbin 5 is formed at the outer peripheral portion thereof. A resilient 
member S such as a spring is is disposed in the cylindrical groove 6a and 
protrudes therefrom. The bobbin 5 wound around the solenoid coil 5a is 
disposed in the annular groove 6b and completely therein. 
The fixed iron core 6, with the bobbin 5 and the resilient member S, is 
disposed in the protective cap 7 such that the undersurface of the fixed 
iron core 6 is positioned inwardly of the open end face of the protective 
cap 7. Under this arrangement, a first vacant chamber 8a is formed in the 
protective cap 7 between the open end face of the protective cap 7 and the 
undersurface of the fixed iron core 6. 
An O-ring groove 7a is circumferentially formed on the open end face of the 
protective cap 7 and accommodates an O-ring R. A contact portion between 
the protective cap 7 and the valve box 3 is sealed by this O-ring R, so 
that fluid can be prevented from leaking through the contact portion. 
An input port 9 for fluid is formed at one side surface of the valve box 3 
and an output port 10 for fluid is formed at the other side surface 
thereof. The valve box 3 has a second vacant chamber 8b at an upper open 
portion thereof, and this second vacant chamber 8b is connected to the 
first vacant chamber 8a of the solenoid section 2, to thereby form a valve 
chest 8. 
The center of the vacant chamber 8b of the valve box 3 is provided with a 
valve seat 11, opposite the center of the undersurface of the solenoid 
section 2 and spaced a predetermined distance therefrom. 
A valve port 12 of the valve seat 11 and the output port 10 communicate 
with each other through an output flow path 13 defined in the valve box 3. 
The valve port 12 of the valve seat 11 and the input port 9 are 
communicate with each other through an input flow path 9a defined in the 
valve box 3 and the valve chest 8. 
The movable member 4 is formed of a disk-shaped magnetic material. A valve 
body 4a formed of an elastic material such as rubber is bonded to the 
center of the undersurface of the movable member 4. As shown FIGS. 2 and 
3, in the movable member 4, includes flow-in ports 4b provided around the 
valve body 4a at four positions for example. The movable member 4 is 
provided in the valve chest 8 between the undersurface of the fixed iron 
core 6 and the valve seat 11. The outer peripheral side surface of the 
movable member 4 is spaced a predetermined distance from the inner side 
surface of the valve chest 8. As shown in FIG. 1, during non-excitation of 
the solenoid section 2, the movable member 4 is urged toward the valve 
seat 11 from the side of the solenoid section 2 by a biasing force of the 
resilient member S such as the spring and by fluid pressure of the fluid 
which has flowed into the valve chest 8 on the side of the first vacant 
chamber 8a, whereby the valve body 4a is urged against the valve seat 11, 
so that the valve port 12 is closed. 
During excitation of the solenoid section 2, the movable member 4 is 
attracted by magnetic attraction of the solenoid section 2, and is 
separated from the valve seat 11 against the biasing force of the 
resilient member S and the fluid pressure of the fluid. The top surface of 
the movable member 4 abuts against the undersurface of the fixed iron core 
6, to thereby open the valve port 12. 
Thus, as excitation and non-excitation the solenoid section 2 are 
alternately repeated, the movable member 4 is reciprocated between the 
undersurface of the fixed iron core 6 and the valve seat 11. However, 
during this reciprocatory movement, the movable member 4 would not 
necessarily perform regular reciprocatory movement, because the outer 
peripheral portion of the movable member 4 may come into contact with or 
slide on the inner wall surface of the valve chest 8. To prevent such 
contact and sliding, the movable member 4 is supported in the valve chest 
8 by a support member 14 which limits displacement of the movable member 4 
in a direction perpendicular to the reciprocatory movement, i.e. in a 
directive horizontal to the movable member as shown in FIG. 1. 
The support member 14 is formed of an elastic material such as rubber and 
synthetic resin. The shape of the support member 14 as shown in FIGS. 1 
and 2 is of a generally annular disk shape. The support member 14 is 
provided on the inner peripheral edge of the top surface with two 
oppositely disposed raised coupling portions. The raised coupling portions 
14a are coupled and fixed into corresponding coupling grooves 4c formed on 
the outer peripheral edge of the undersurface of the movable member 4. 
Thus the inner peripheral edge portion of the support member 14 and the 
outer peripheral edge portion of the movable member 4 are connected to 
each other. The outer peripheral edge of the support member 14 is clamped 
between a stepped portion 3a at the top open end of the valve box 3 and 
the bottom open end of the protective cap 7. Thus the outer peripheral 
edge of the support member 14 and the inner wall surface of the valve 
chest 8 are connected to each other. The movable member 4 is supported in 
the valve chest 8 by the support member 14 thus connected. Under this 
arrangement the movable member 4 can be prevented from being moved or 
displaced in the horizontal direction as shown in FIG. 1. The 
reciprocatory movement of the movable member 4 between the valve seat 11 
and the undersurface of the fixed iron core 6 is not hindered by the 
support member 14. 
In the solenoid valve shown in FIG. 3, the support member 14, has a 
construction of two plate pieces, wherein most of the annular disk 14 as 
shown in FIG. 2 is cut away. The two plate pieces are provided on the 
movable member 4 opposite to each other. 
The solenoid shown in FIG. 3 is not different from the solenoids of FIG. 1 
or 2 in any respect other than the above. Thus the parts shown in FIG. 3 
are indicated by the same reference numerals as used in FIGS. 1 and 2 for 
simplification. 
Operation of the solenoid valve 1 will now be described. 
When the solenoid coil 5a of the solenoid section 2 is not energized, as 
shown in FIG. 1, the movable member 4 is urged toward the valve seat 11 
from the underside of the solenoid section 2 by the biasing force of the 
resilient member S and by the fluid pressure of the fluid on the side of 
the first vacant chamber 8a of the valve chest 8. Thus the valve body 4a 
of the movable member 4 is urged against the valve seat 11, to close the 
valve port 12. With the valve port 12 closed, the fluid which flowed into 
the valve chest 8 through the input port 9 does not flow out from the 
output port 10 through the output flow path 13. 
However, when the solenoid coil 5a of the solenoid section 2 is energized, 
the movable member 4, attracted by the magnetic attraction of the solenoid 
section 2, separates from the valve seat 11 against the biasing force of 
the resilient member S and the fluid pressure of the fluid. The top 
surface of the movable member 4 is attracted to the undersurface of the 
fixed iron core 6, to thereby open the valve port 12. With the valve port 
12 opened, the fluid flows into the valve chest 8 from the input port 9 
along the input flow path 9a. The fluid in the valve chest 8 flows to the 
output port 10 from the valve port 12 along the output flow path 13. 
As described above, deenergizing and energizing of the solenoid coil 5a are 
alternately repeated, whereby the movable member 4 is reciprocated between 
the undersurface of the fixed iron core 6 and the valve seat 11 in the 
vertical direction as viewed in FIG. 1, to thereby open or close the valve 
port 12. 
During reciprocatory movement of the movable member 4, the movable member 4 
is by the support member 14 from being displaced in a direction 
perpendicular to the reciprocatory movement, i.e. in a horizontal 
direction as viewed in FIG. 1. Thus the outer peripheral portion of the 
movable member 4 does not come into contact with or slide on the inner 
wall surface of the valve chest 8. In this manner the valve port ON-OFF 
operation of the movable member 4 is stable and reliable and the outer 
peripheral portion of the movable member 4 and the inner wall surface of 
the valve chest 8 can be prevented from being worn. 
It should be noted that, the support member 14 is formed of elastic 
material such as rubber and synthetic resin. However, the support member 
14 may be formed of a thin-wall metal plate or a filament member such as 
wire and thread. 
The solenoid valve according to the present invention has a movable member 
with a valve body, that is reciprocated between the solenoid section of 
the valve chest and the valve seat by magnetic attraction of the solenoid 
section, to thereby open or close the valve port. The solenoid valve is 
constructed such that the movable member is supported in the valve chest 
by a support member which prevents displacement of the movable member in 
the direction perpendicular to the moving direction. Thus, the following 
advantages can be obtained. 
(1) The movable member is supported in the valve chest by the support 
member which limits displacement of the movable member in the direction 
perpendicular to the moving direction. Under this arrangement the movable 
member is not displaced in the direction perpendicular to the direction of 
movement of the movable member, so that the outer peripheral portion of 
the movable member can be prevented from coming into contact with or 
sliding on the inner wall surface of the valve chest. 
(2) Based on Item (1), the movable member obviates and operational failure 
due to contact with the inner wall surface of the valve chest, so that the 
valve port ON-OFF operation is stabilized and reliably performed. 
(3) Based on Item (1), the outer peripheral portion of the movable member 
and the inner wall surface of the valve chest can be prevented from being 
worn. Thus the problem of dust that is produced by wear is avoided and no 
such dust flows into the fluid circuit to cause troubles in other 
components. Smooth operation of the movable member is not hindered by the 
above-described wearing process. 
Another embodiment of the solenoid valve as shown in FIG. 4 is generally 
indicated by the reference number 101. The solenoid valve 101 includes a 
solenoid section 102, a valve box 103 connected thereto, a valve body 104 
and a movable member 105. 
The solenoid section 102 includes a bobbin 106 wound with a solenoid coil 
106a, a columnar fixed iron core 107 and a protective cap 108 covering the 
outer periphery of the fixed iron core 107. The center of the columnar 
fixed iron core 107 is provided in the undersurface with a recess 107a for 
receiving a resilient member 109, and at the outer peripheral portion with 
an annular groove 107b for receiving the bobbin 106. The resilient member 
109 such as a spring is disposed in the recess 107a and the protrudes 
therefrom. The bobbin 106 is disposed in the annular groove 107b and 
completely recessed therein. The fixed iron core 107 having the resilient 
member 109 and the bobbin 106 is disposed in the protective cap 108. 
Circumferentially formed on the open bottom end face of the protective cap 
108 is an O-ring groove 108a, into which is disposed an O-ring 200R. A 
contact portion between the protective cap 108 and the valve box 103 is 
sealed by the O-ring 200R, thus preventing fluid from leaking. 
An input port 110 for fluid is formed at one side of the lower half portion 
of the valve box 103, and an output port 111 is formed at the other side 
of the lower half portion of the valve box 103, respectively. The valve 
box 103 is provided at an upper half portion thereof with a valve chest 
112. The valve chest 112 of the valve box 103 is constructed such that the 
inner diameter at the upper side thereof is large and the inner diameter 
at the lower side is small, whereby a checking portion 113 for the movable 
member 105 is formed at the inner peripheral portion by the difference in 
the inner diameters. The center of the valve chest 112 includes a valve 
seat 114 opposite to the center of the undersurface of the solenoid 
section 102 and spaced predetermined therefrom. 
A valve port 114a of the valve seat 114 is communicates with the output 
port 111 along an output flow path 111a defined in the valve box 103. The 
valve port 114a of the valve seat 114 communicates with the input port 110 
along an input flow path 110a defined in the valve box 103 and the valve 
chest 112. 
The movable member 105 is formed of a disk-shaped magnetic material, and 
flow-in ports 105a are provided, for example, at four positions on the 
outer peripheral portion thereof. The center of the movable member 105 is 
provided with a coupling hole 105b for loosely accommodating the valve 
body 104. The coupling hole 105b is constructed such that the inner 
diameter at the upper side thereof is large and the inner diameter at the 
lower side is small, such that an engaging portion 105c is formed on the 
inner peripheral portion thereof by the difference in the inner diameters. 
The valve body 104 is formed of an elastic material such as rubber and soft 
synthetic resin and is not fixed to the movable member 105. Furthermore, 
the valve body 104 is formed at the upper portion thereof with an 
engageable flange portion 104a. 
The valve body 104 is loosely received into the coupling hole 105b such 
that the engageable flange portion 104a comes into abutting contact with 
the engaging portion 105c of the coupling hole 105b. The valve body 104 is 
biased toward the valve seat 114 by a resilient member 109 such as a 
spring protruding from the recess 107. 
During non-excitation of the solenoid section 102, the valve body 104 is 
urged toward the valve seat 114 from the underside of the solenoid section 
102 by the biasing force of the resilient member 109 and by fluid pressure 
of fluid which has flowed into the valve chest 112. Thus the valve body 
104 is urged against the valve seat 114, to close the valve port 114a. 
With the valve port 114a closed, as shown in FIG. 4, the movable member 
105 is interposed between the checking portion 113 and the engageable 
flange portion 104a of the valve body 104 with play in the vertical 
direction, and is positioned to the side of the valve seat 114. 
During excitation of the solenoid section 102, the movable member 105 which 
is positioned to the side of the valve seat 114 is attracted by the 
magnetic attraction of the solenoid section 102 into abutting contact with 
the undersurface of the fixed iron core 107 of the solenoid section 102. 
When the movable member 105 moves from the side of the valve seat 114 
toward the solenoid section 102, the engageable flange portion 104a of the 
valve body 104 is engaged with the engaging portion 105c. The valve body 
104 is thus pushed from the valve seat 114 against the biasing force of 
the resilient member 109 and fluid pressure of the fluid which has flowed 
into the valve chest 112, to thereby open the valve port 114a. In other 
words, when the movable member 105 moves toward the solenoid section 102, 
the valve body 104 moves toward the solenoid section 102 in association 
with the movement of the movable member 105. 
However, when the movable member 105 moves toward the valve seat 114 due to 
demagnetization of the solenoid section 102, the valve body 104 is moved 
toward the valve seat 114 by the biasing force of the resilient member 109 
separately of the movement of the movable member 105. In this manner the 
valve body 104 is urged against the valve seat 114, to thereby close the 
valve port 114a. In other words, movement of the valve body 104 toward the 
valve seat 114 is not influenced by movement of the movable member 105 
toward the valve seat 114. The valve body 104 is moved toward the valve 
seat 114 by the biasing force of the resilient member 109 independently of 
the movable member 105. 
Operation of the solenoid valve 101 will now be described. 
When the solenoid coil 106a of the solenoid section 102 is not energized, 
as shown in FIG. 4, the valve body 104 is urged toward the valve seat 114 
from the underside of the solenoid section 102 by the biasing force of the 
resilient member 109. Fluid pressure of fluid which has flowed into the 
valve chest 112 also urges the valve body 104 against the valve seat 114, 
to thereby close the valve port 114a. The movable member 105, not being 
subjected to magnetic attraction of the solenoid section 102, is 
positioned at the side of the valve seat 114, between the checking portion 
113 and the engageable flange portion 104a of the valve body 104, with 
play in the vertical direction. The valve port 114a is closed, to prevent 
flow of fluid between the input port 110 and the output port 111. 
When the solenoid coil 106a of the solenoid section 102 is energized, the 
movable member 105 is attracted by the magnetic attraction of the solenoid 
section 102 to move toward the solenoid section 102, into abutting contact 
with the undersurface of the fixed iron core 107 of the solenoid section 
102. During such movement of the movable member 105, the engageable flange 
portion 104a of the valve body 104 is engaged with the engaging portion 
105c of the movable member 105 to cause upward movement of the valve body 
104. The valve body 104 thus separates from the valve seat 114 against the 
biasing force of the resilient member 109 and the fluidal pressure of 
fluid which has flowed into the valve chest 112 to open the valve port 
114a. The valve body 104 thus moves toward the solenoid section 102 in 
association with the movement of the movable member 105. When the valve 
port 114a is opened fluid flows from the input port 110 toward the output 
port 111 and outwardly of the output port 111, to actuate a given fluid 
pressure component, not shown. 
When the solenoid coil 106a is subsequently deenergized to demagnetize the 
solenoid section 102, the movable member 105 is released from abutting 
contact with the undersurface of the fixed iron core 107. At the same 
time, the valve body 104 is moved toward the valve seat 114 by the biasing 
force of the resilient member 109 and by the fluid pressure of the fluid 
in the valve chest 112. The valve body 104 is thus urged against the valve 
seat 114, to close the valve port 114a. Due to such movement of the valve 
body 104, the movable member 105 is also moved toward the valve seat 114. 
After the valve body 104 comes into contact with the valve seat 114, the 
movable member 105 continues to move by its inertial force until the 
engaging portion 105c for the valve body separates from the engageable 
flange portion 104a and comes into abutting contact with the checking 
portion 113 and stops. 
During movement of the valve body 104 and the movable member 105 toward the 
valve seat 114, the valve body 104 movement is not influenced by movement 
of the movable member 105 toward the valve seat 114. The valve body 104 
moves toward the valve seat 114 independently of the movable member 105, 
and is urged against the valve seat 114 without being directly subjected 
to the inertial force of movement of the movable member 105 toward the 
valve seat 114. Accordingly, the inertial force of the movable member 105 
is not directly applied to the contact portion between the valve body 104 
and the valve seat 114. Thus the contact portions of the valve body 104 
and the valve seat 114 can be prevented from being worn and/or damaged by 
the above-described inertial force of the movable member 105. 
The deenergizing and energizing of the solenoid coil 106a are alternately 
repeated, whereby the valve body 104 and the movable member 105 are 
rciprocated between the undersurface of the fixed iron core 107 and the 
valve seat 114 in the vertical direction as viewed in FIG. 4, to thereby 
open or close the valve port 114a. 
The solenoid valve 101 shown in FIG. 5 is identical in construction with 
the solenoid valve shown in FIG. 4 except that the checking portion 113 
for the movable member is slightly different in construction from the one 
in the embodiment shown in FIG. 4. The portions or members in FIG. 5 
corresponding to those in the embodiment shown in FIG. 4 are depicted by 
the same reference numerals to avoid repeating the description. More 
specifically, the checking portion 113 for the movable member in the 
embodiment shown in FIG. 5 is a checking member 113a formed of an elastic 
material such as rubber and soft synthetic resin. The checking member 113a 
is of annular shape and is provided at the bottom portion of the inner 
periphery of the valve chest 112. The checking portion 113 for the movable 
member is thus formed of the elastic material as described above. When the 
movable member 105 moves toward the valve seat 114 to come into abutting 
contact with the checking portion 113, an impact shock by the inertial 
force of the movable member 105 can be satisfactorily relieved. With this 
construction, the movable member 105 and the checking portion 113 can be 
prevented from being worn and/or damaged due to the abutting contact of 
the movable member 105 with the checking portion 113. 
The solenoid valve of this embodiment includes the movable member attracted 
by th magnetic attraction of the solenoid section in the valve chest to 
move between the solenoid section and the valve seat,; and a valve body 
provided on this movable member coming into abutting contact with or being 
separated from the valve seat to close or open the valve port. This 
embodiment also includes a valve body not fixed to the movable member so 
that the valve body moves toward the solenoid section in association with 
the movement of the movable member toward the solenoid section. However, 
the valve body moves toward the valve seat uninfluenced by movement of the 
movable member toward the valve seat to provide the following advantages. 
The valve body is not influenced by movement of the movable member toward 
the valve seat and moves toward the valve seat independently of the 
movable member. The valve body is urged against the valve seat without 
being directly subject to the inertial force due to the movement of the 
movable member toward the valve seat. Thus the inertial force of the 
movable member is not directly applied to the contact portion between the 
valve body and the valve seat, so that the contact portion between the 
valve body and the valve seat, particularly the valve body can be 
prevented from being worn and/or damaged by the inertial force of the 
movable member. 
With the above-described advantage, the solenoid valve can be improved in 
durability and reliability. 
A solenoid valve 201 of the embodiment shown in FIG. 6 includes a solenoid 
section 202, a valve box 203 connected thereto, a valve body 204 and a 
movable member 205. 
The solenoid section 202 is constituted by a bobbin 206 wound with a 
solenoid coil 206a, a columnar fixed iron core 207 and a protective cap 
208 covering the outer periphery of the fixed iron core 207. The center of 
the columnar fixed iron core 207 is provided in the undersurface with a 
cylindrical groove 207a for coupling a resilient member, and, at the outer 
peripheral portion with an annular groove 207b for receiving the bobbin. A 
resilient member 209 such as a spring is disposed in the cylindrical 
groove 207a and protrudes therefrom. The bobbin 206 is disposed in the 
annular groove 207b of the fixed iron core 207 and completely recessed 
therein. The fixed iron core 207 having the resilient member 209 and the 
bobbin 206 is disposed in the protective cap 208. 
Circumferentially formed on the open end face of the protective cap 208 is 
an O-ring groove 208a, into which is disposed an O-ring 200R. A contact 
portion between the protective cap 208 and the valve box 203 is sealed by 
the O-ring 200R, so that fluid is prevented from leaking through the 
contact portion. 
An input port 210 is formed at one side of the lower half portion of the 
valve box 203 and an output port 211 is formed at the other side of the 
lower half portion. The valve box 203 is provided in the upper portion 
with a valve chest 212. The center of valve chest 212 is provided a valve 
seat 214, which is opposite to the center of the undersurface of the 
solenoid section 202 and spaced a predetermined distance therefrom. 
A valve port 214a of the valve seat 214 and the output port 211 communicate 
with each other along an output flow path 211a defined in the valve box 
203. The valve port 214a of the valve seat 214 and the the input port 210 
communicate with each other along an input flow path 210a define in the 
valve box 203 and the valve chest 212. 
The movable member 205 is formed of a disk-shaped magnetic material, and 
flow-in ports 205a are provided, for example, at four positions on the 
outer peripheral portion. The center of the movable member 205 is provided 
with a through-hole 205b extending in the moving direction, i.e. in the 
vertical direction in the drawing for receiving a valve body. The top 
surface of the movable member 205 is provided with a plurality of radial 
grooves 205c for receiving shock-absorbing members 215. The shock 
absorbing members 215 are each formed of an elastic material and protrude 
slightly from the top surface of the movable member 205. The surface 215a 
of the shock-absorbing members 215, which is opposed to the solenoid 
section 202, forms a portion of the movable member 205 which abuts against 
the solenoid section 202. 
The valve body 204 is formed of an elastic material such as rubber and soft 
synthetic resin. The valve body 204 is disposed in the through-hole 205b. 
A surface of the valve body 204, which is opposed to the solenoid section 
202, is slightly raised from the top surface (one surface on the side of 
the solenoid section) of the movable member 205 similar to the 
shock-absorbing members 215, and this opposed surface 204a forms the 
portion of the movable member 205, which is abutted against the solenoid 
section 202. 
The valve body 204 is biased toward the valve seat 214 by the resilient 
member 209 such as the spring or the like which protrudes from the 
cylindrical groove 207a member. 
Operation of the solenoid valve 201 will now be described. 
When the solenoid coil 206a of the solenoid section 202 is not energized, 
as shown in FIG. 6, the valve body 204 and the movable member 205 are 
urged toward the valve seat 214 from the underside of the solenoid section 
202 by the biasing force of the resilient member 209. Fluid pressure of 
fluid which has flowed into the valve chest 212, also urges the valve body 
204 against the valve seat 214, to thereby close the valve port 214a. With 
the valve port 214a being closed, fluid does not flow between the input 
port 210 and the output port 211. 
When the solenoid coil 206a of the solenoid section 202 is energized, the 
valve body 214 and the movable member 205, are attracted by magnetic 
attraction of the solenoid section 202 to move toward the solenoid section 
202. The valve body 204 is separated from the valve seat 214 to open the 
valve port 214a. Further, the surface 204a of the valve body 204, which is 
opposed to the solenoid section 202, and the surface 214a of the 
shock-absorbing member 215, which is also opposed to the solenoid section 
202, are brought into abutting contact with the undersurface of the fixed 
iron core 207. 
The impact shock at the time of abutting is relieved by the elasticity of 
the valve body 204 and the shock-absorbing member 215, such that a 
shocking absorbing effect of the movable member 205 against the solenoid 
section 202 is obtained. Under this arrangement the movable member 205 and 
the solenoid section 202 can be prevented from being worn due to the 
abutting action. 
Since, at the time of abutting, the surface 204a of the valve 204, and the 
surface 215a of the shock-absorbing member 215, are slightly raised from 
the top surface of the movable member 205, the top surface of the movable 
member 205 is not abutted against the undersurface of the fixed iron core 
207 of the solenoid section 202. Accordingly, under this arrangement, the 
movable member 205 and the solenoid section 202 can be prevented from 
being worn. 
When the valve port 214a is opened the fluid flows from the input port 210 
to the output port 211, outwardly through the output port 211 and actuates 
a given fluid pressure component, not shown. 
When the solenoid coil 206a is subsequently deenergized to demagnetize the 
solenoid section 202, the valve body 204 and the movable member 205 are 
separated from the fixed iron core 207 of the solenoid section 202 by the 
biasing force of the resilient member 209 and by the pressure of the fluid 
in the valve chest 212 to move toward the valve seat 214. The valve body 
204 is thus urged against the valve seat 214, to thereby close the valve 
port 214a. 
The deenergizing and energizing of the solenoid coil 206a are alternately 
repeated, whereby the valve body 204 and the movable member 205 are 
reciprocated between the undersurface of the fixed iron core 207 and the 
valve seat 214 in the vertical direction as viewed in FIG. 6, to thereby 
open or close the valve port 214a. 
Although the movable member 205 in this embodiment is provided with the 
shock-absorbing member 215, the shock-absorbing member 215 may be omitted. 
As indicated by a broken line in FIG. 6, a shock-absorbing member 216 may 
be provided in the center of the undersurface of the fixed iron core 207, 
to further improve the shock-absorbing effect. 
The solenoid valve of this embodiment includes the movable member attracted 
by the magnetic attraction of the solenoid section for movement in the 
valve chest between the solenoid section and the valve seat. The movable 
member is formed with a through-hole extending in the moving direction for 
receiving a valve body, a valve body formed of an elastic material 
disposed in the through-hole and the surface of the valve body, forms a 
portion of the movable member, which is abutted against the solenoid 
section, to provide the following advantages. 
The impact shock between the movable member and the solenoid section at the 
time of abutting is relieved by the valve body for ON-OFF operation of the 
valve port. The valve body functions as a shock-absorbing member in 
addition to its ON-OFF function in operating the valve port. The the 
construction which provides a shock-absorbing effect between the movable 
member and the solenoid section can be simplified. 
The valve body in its function as a shock-absorbing member is disposed in 
the through-hole for receiving the valve body, whereby the thickness of 
the valve body is not restricted by the depth of the through hole. The 
thickness of the valve body can be made larger than the depth of the 
through-hole, so that the valve body being thick and highly elastic can be 
used to obtain a satisfactory shock-absorbing effect. 
The movable member and the solenoid section can be prevented from being 
worn at the time of abutting, so that the solenoid valve can be improved 
in durability and reliability. 
Even if the thickness of the movable member is decreased, the thickness of 
the valve body is not restricted by the thickness of the movable member. 
Thus the thickness of the movable member can be decreased without reducing 
the shock-absorbing effect of the valve body. With the thickness of the 
movable member being decreased, the inertial force of the movable member 
is reduced during movement. Thus the impact shock of the valve body, when 
it abuts against the solenoid section and the valve seat, and the impact 
shock of the movable member, when it abuts against the solenoid section, 
can be relieved. 
Wear of the valve body due to its abutting against the solenoid section and 
the valve seat and wear of the movable member due to its abutting against 
the solenoid section can be prevented, so that the solenoid valve can be 
improved in durability and reliability. 
A solenoid valve 301 of the embodiment shown in FIG. 7 is a three part 
solenoid valve, and includes a solenoid section 302, a valve box 303 
connected thereto, a valve body 304 and a movable member 305. 
The solenoid section 302 includes a bobbin 306 wound with a solenoid coil 
306a, a fixed iron core 307 and a protective cap 308 covering the fixed 
iron core 307. 
A first valve port 307a is formed in the center of the bottom portion of 
the fixed iron core 307, and a discharge port 308a is formed in the center 
of the top portion of the protective cap 308. The first valve port 307a 
and the discharge port 308a communicate with each other along a discharge 
flow path 308b extending through the center of the fixed iron core 307. 
The center of the bottom portion of the fixed iron core 307 is formed with 
a recess 307c, into which is disposed a biasing means 309 such as a spring 
which protrudes therefrom. 
An input port 310 is formed at one side (at the right in FIG. 7) of the 
valve box 303, and an output port 311 is formed at the opposite side (at 
the left in FIG. 7) of the valve box 303. In the center of the top portion 
of the valve box 303, a second valve port 303a is formed which is opposite 
the first valve port 307a and spaced a predetermined distance therefrom. 
The input port 310 and the output port 311 communicate with each other 
through the second valve port 303a, and the output port 311 and the 
discharge port 308a communicate with each other through the first valve 
port 307a. 
A valve chest 312 is formed at the junction between the solenoid section 
302 and the valve box 303. The valve chest 312 is provided a movable 
member 305 which moves between a first valve seat 307b of the first valve 
port 307a and a second valve seat 303b of the second valve port 303a by 
electromagnetic action of the solenoid section 302. 
The movable member 305 is supported in the valve chest 312 by a plurality 
of support members 313 each formed of an elastic member such as rubber and 
synthetic resin. Based on the support provided by the support member 313, 
the movement of the movable member 305 is restricted in the direction 
perpendicular to the moving direction thereof i.e, movement of the movable 
member 305 is not permitted in the horizontal direction in FIG. 7. 
The movable member 305 is formed of a thin plate-shaped magnetic material. 
The movable member 305 is provided on the outer peripheral portion thereof 
with input/output ports 305a that extend through the movable member 305. 
Circumferentially formed on the outer surface of the movable member 305 on 
the side of the solenoid section 302 is a shock-absorbing member 305b 
formed of an elastic material such as rubber and soft synthetic resin. The 
shock absorbing member 305b protrudes slightly from the movable member 
305. 
A coupling hole 305c for loosely accomodating the valve body 304 is formed 
in the center of the movable member 305. The coupling hole 305c is formed 
such that the upper portion has a large diameter and the lower portion has 
a small diameter. An engaging portion 305d for the valve body 304 is 
formed in the inner peripheral portion by this difference in the inner 
diameters. 
The valve body 304 is formed of an elastic material such as rubber and soft 
synthetic resin and is provided at the top portion thereof with an 
engageable flange portion 304a. 
The engageable flange portion 304a of the valve body 304 is abutted against 
the engaging portion 305d of the movable member 305 and is loosely 
disposed in the coupling hole 305c. The valve body 304 is biased toward 
the second valve seat 303b by the biasing means 309, and is not fixed to 
the movable member 305. 
During excitation of the solenoid section 302, the movable member 305 is 
moved toward the first valve port 307a by the magnetic attraction of the 
solenoid section 302. The valve body 304 is moved in association with the 
magnetically induced movement of the movable member 305 and is separated 
from the second valve seat 303b to open the second valve port 303a. The 
valve body 304 is thus abutted against the first valve seat 307b to close 
the first valve port 307a. 
However, when the movable member 305 moves toward the second valve port 
303a due to the demagnetization of the solenoid section 302, the valve 
body 304 is moved toward the second valve port 303a by the biasing force 
of the biasing means 309 uninfluenced by the movement of the movable 
member 305. The valve body 304 is separated from the first valve seat 307b 
to open the first valve port 307a, and is abutted against the second valve 
seat 303b to close the second valve port 303a. 
The valve body 304 protrudes slightly from the surface of the movable 
member 305 on the side of the solenoid section 302, so that the impact 
shock between the movable member 305 and the fixed iron core 307 can be 
absorbed by the protruding portion of the valve body 304. 
Operation of the three-port type solenoid valve 301 will now be described. 
During deexcitation of the solenoid section 302, as shown in FIG. 7, the 
valve body 304 is abutted against the second valve seat 303b by the 
biasing force of the biasing means 309 to close the second valve port 
303a. 
The movable member 305 is positioned on the side of the second valve port 
303a because the biasing force is imparted to the movable member 305 
through the valve body 304. 
When the solenoid section 302 is excited from the state shown in FIG. 7, 
the movable member 305 is moved toward the first valve port 307a by 
magnetic attraction of the solenoid section 302 against the biasing force 
of the biasing means 309. In association with movement of the movable 
member 305, the valve body 304 is moved toward the first valve port 307a, 
and is separated from the second valve seat 303b to open the second valve 
port 303. The valve body 304 is thus abutted against the first valve seat 
307b to close the first valve port 307a. 
The impact shock between the movable member 305 and the fixed iron core 307 
during this excitation can be reliably absorbed by the valve body 304 and 
the shock-absorbing member 305b because the valve body 304 which impinges 
upon the first valve seat 307b is formed of an elastic member. Furthermore 
the shock-absorbing member 305b which impinges upon the fixed iron core 
307 is provided on the movable member 305. 
When the second valve port 303a is opened and the first valve port 307a is 
closed, the fluid such as pneumatic pressure which has been fed to the 
input port 310 flows from the input port 310 to the output port 311 
through the second valve port 303a, and is outputted by the output port 
311. The outputted fluid can thus operate a fluidal pressure component, 
not shown, such as, for example, a single-acting cylinder. 
When the solenoid section 303 is subsequently demagnetized, the valve body 
304 is moved toward the second valve port 303a by the biasing force of the 
biasing means 309, and is separated from the first valve seat 307b to open 
the first valve port 307a. The valve body 304 thus abuts against the 
second valve seat 303b to close the second valve port 303a. 
Due to the movement of the valve body 304, the movable member 305 also 
moves toward the second valve port 303a and is restored to the position 
shown in FIG. 7. 
The valve body 304, when moving toward the second valve port 303a, is not 
influenced by the movement of the movable member 305 and is moved toward 
the second valve port 303a by the biasing force of the biasing means 309 
independently of the movable 305. Thus the valve body 304 is abutted 
against the second valve seat 303b without being subject to the inertial 
force due to the movement of the movable member 305. 
At the time of abutting between the valve body 304 and the second valve 
seat 303b, the inertial force of the movable member 305 is not directly 
applied to either member, so that the valve body 304 and the second valve 
seat 303b can be reliably prevented from being worn and/or damaged. 
When the first valve port 307a is opened and the second valve port 303a is 
closed, the flow of the fluid between the input port 310 and the output 
port 311 is changed over to permit flow of fluid between the output port 
311 and the discharge port 308a. Due to this change-over, the fluid on the 
back pressure side of the fluid pressure working component, not shown, is 
discharged to the outside through the output port 311, the first valve 
port 307a and the discharge port 308a. 
In this case, the fluid going through the valve chest 312 flows along the 
outer periphery of the movable member 305 between the support members 313, 
313, . . . and through the input/output ports 305. However, the affect of 
the thickness of the movable member 305 on the fluid flow is low because 
the movable member 305 is of the thin plate shape, enabling the fluid flow 
to be smoothly carried out. 
The valve body 304 and the movable member 305 are reciprocated between the 
first valve port 307a and the second valve port 303a in the vertical 
direction as viewed in FIG. 7. During this reciprocatory movement, the 
movable member 305 is restricted in displacement in a direction 
perpendicular to the direction of the reciprocatory movement thereof, i.e. 
the movable member 305 is not permitted to move in the horizontal 
direction in FIG. 7. 
Because of the limited movement of the movable member 305 the outer 
peripheral portion of the movable member 305 does not come into contact 
with or slide on the inner wall surface of the valve chest 312. Thus 
unreliability and instability of the ON-OFF operations of the solenoid 
valve 301 by the movable member 305 and/or wear of the outer peripheral 
portion of the movable member 305 and the valve chest 312 can be 
positively avoided. 
Furthermore, in the solenoid valve 301 ON-OFF operations of the first valve 
port 307a and the second valve port 303a are carried out by the single 
valve body 304, so that the solenoid valve can be rendered compact in size 
and simplified in construction. 
Further, in the solenoid valve 301 the impact shock between the movable 
member 305 and the fixed iron core 307 is absorbed by the valve body 304 
and the shock-absorbing member 305b, which are formed of elastic 
materials. Since the spring in the movable member does not absorb the 
impact shock the solenoid valve can be rendered compact in size and 
simplified in construction. 
The present invention has been specifically described with reference to the 
foregoing embodiments. However, the present invention need not necessarily 
be limited to the above embodiments and, cover various modifications 
without departing from the gist thereof. 
For example, the support member 313 is formed of elastic material such as 
rubber and soft synthetic resin. However, the support member 313 may be 
formed of a thin metallic plate or a filament member such as wire and 
thread. 
Furthermore, the solenoid valve 301 is applied to a fluid pressure working 
component such as a single-acting type cylinder. However, the solenoid 
valve may be applied to any other fluid pressure working component or 
applied as a control valve for a fluid pressure working valve. 
Further, the solenoid valve 301 may be formed into a two-port type solenoid 
valve. 
The solenoid valve 301 is constructed such that the solenoid valve includes 
the first valve port formed on the solenoid section side, the second valve 
port opposed to this first valve port, the movable member being moved by 
the magnetic force of the solenoid section between the first and second 
valve ports and the valve body provided on this movable member. The 
movable member is supported by the support member or members for limiting 
the displacement of the movable member in the direction perpendicular to 
the moving direction thereof. The valve body is not fixed to the movable 
member and can move toward the second valve port without being influenced 
by the movement of the movable member toward the second valve port. One 
surface of the valve body is abutted against or separated from the first 
valve seat of the first valve port to close or open the first valve port 
and the other surface of the valve body is abutted against or separated 
from the second valve seat of the second valve port to close or open the 
second valve port, to provide the following advantages. 
The movable member is supported by the support member or members, whereby 
the movable member is prevented from displacement in the direction 
perpendicular to the moving direction. Under this arrangement the outer 
peripheral portion of the movable member does not come into contact with 
or slide on the inner wall surface of the valve chest. Thus the outer 
peripheral portion can be prevented from being worn. The outer peripheral 
portion of the movable member does not come into contact with or slide on 
the inner wall surface chest. Thus the movable member can be operated 
smoothly and reliably. 
The valve body is not fixed to the movable member and moves toward the 
second valve port without being influenced by movement of the movable 
member toward the second valve port. During the movement of the movable 
member toward the second valve port, the valve body is moved toward the 
second valve port and is abutted against the second valve seat without 
being subject to the inertial force of the movable member. Thus the valve 
body and the second valve seat can be effectively prevented from being 
worn and/or damaged. 
The first and second valve ports are ON-OFF operated by the single valve 
body provided on the movable member, so that the solenoid valve can be 
rendered compact in size and simplified in construction. 
With the construction of the above-described embodiments, the valve port 
ON-OFF operation is stabilized and can be reliably carried out. 
With the construction of the above-described embodiments, the solenoid 
valve can be improved in durability. 
With the construction of the above-described embodiments, the solenoid 
valve can be improved in operating reliability.