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Patent Abstract
A solenoid valve for a brake system, in which a filter formed in
a mesh structure by injection molding is installed on the outer
circumference of the lower part of a valve housing below projecting
parts, thereby causing the outer circumference of the filter to
be deformed so as to decrease the pressing force of the filter,
when the filter is assembled with a modulate block, so that the
filter is easily assembled with the modulate block, not requiring
a sealing member outside the valve housing so that the production
costs of the solenoid valve products are reduced, and preventing
the generation of foreign substances between the valve housing and
the modulate block when the armature vertically moves.
Patent Claims
What is claimed is:
1. A solenoid valve for a brake system comprising: a coil for forming
an electromagnetic field when current is applied thereto; a sleeve
having a cylindrical shape and passing through the central portion
of the coil; an armature, inserted into one end of the sleeve, vertically
moving by means of the electromagnetic field formed by the coil;
a valve housing, for accommodating the armature, inserted into one
end of the sleeve and provided with an oil route opened and closed
by the armature; a magnet core fixed to the other end of the sleeve
and separated from the armature by a designated interval; a return
spring for returning the armature to the oil route when current
is not applied to the coil; and a filter fixed to the outer circumference
of the lower part of the valve housing by press fit.
2. The solenoid valve according to claim 1, wherein the filter
is formed in a mesh structure by injection molding.
3. The solenoid valve according to claim 2, wherein the filter
is inserted into a modulate block such that both sides of upper
and lower ends of the filter are fixed and sealed into the modulate
block.
4. The solenoid valve according to claim 1, wherein the valve housing
includes: a through hole formed through the central portion of the
valve housing; first projecting parts formed on both portions of
the outer circumference of the valve housing; and second projecting
parts, each of which has an inclined plane.
5. The solenoid valve according to claim 4, wherein a modulate
block, into the valve housing is inserted, includes: a through hole
formed through the central portion of the modulate block for receiving
the valve housing; and indentations in a stepped structure corresponding
to the second projecting parts of the valve housing.
6. The solenoid valve according to claim 4, wherein a part of the
modulate block is deformed, when the valve housing is inserted into
the modulate block, to fix and seal the outer circumference and
the upper end of the valve housing.
7. The solenoid valve according to claim 1, wherein a plurality
of protrusions having a stepped surface are formed on the surface
of the armature contacting the magnet core.
8. A solenoid valve for a brake system, comprising: a sheet portion
including a through hole formed in a longitudinal direction through
the central portion thereof, and a check ball for introducing and
discharging a fluid therethrough; a valve housing having an inner
diameter with a stepped structure for receiving the sheet portion;
an armature, installed in the valve housing, moving up and down
and having a circular sealing structure for opening and closing
an inlet of the sheet portion when power is applied thereto and
released therefrom; a sleeve installed outside the valve housing
and a magnet core; a return spring for returning the armature to
its original position; and a modulate block, into which the valve
housing is inserted, wherein the valve housing is installed in a
longitudinal direction in the sleeve such that a front end of the
valve housing is separated from the magnet core by a designated
interval.
9. The solenoid valve according to claim 8, wherein the valve housing
includes: a through hole formed through the central portion of the
valve housing; first projecting parts formed on both portions of
the outer circumference of the valve housing; and second projecting
parts, each of which has an inclined plane.
10. The solenoid valve according to claim 8, wherein a filter is
installed on the outer circumference of the lower part of the valve
housing below the first and second projecting parts such that the
filter is fixed to the modulate block by press fit for sealing the
inside of the valve.
11. The solenoid valve according to claim 8, wherein the modulate
block, into the valve housing is inserted, includes: a through hole
formed through the central portion of the modulate block for receiving
the valve housing; and indentations in a stepped structure corresponding
to the second projecting parts of the valve housing.
12. The solenoid valve according to claim 10, wherein the filter
is formed in a mesh structure by injection molding.
13. The solenoid valve according to claim 10, wherein the filter
is inserted into the modulate block such that upper and lower ends
of the filter are fixed and sealed into the modulate block.
14. The solenoid valve according to claim 9, wherein the modulate
block is deformed, when the valve housing is assembled with the
modulate block, to fix and seal the valve housing, and the end of
the outer circumference of the valve housing is stepped and provided
with a chamber.
15. The solenoid valve according to claim 8, wherein one end of
the return spring is supported by the sheet portion and the other
end of the return spring is supported by the armature.
Patent Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Korean Patent Application
Nos. 2003-25258 and 2003-25259, filed Apr. 21, 2003, in the Korean
Intellectual Property Office, the disclosure of which is incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a brake system for vehicles,
and more particularly to a solenoid valve for a brake system, which
has an improved assembling efficiency, prevents the generation of
foreign substances, improves the quality of the brake system, and
reduces the manufacturing costs of products.
[0004] 2. Description of the Related Art
[0005] Recently, there are proposed an anti-lock brake systems
(hereinafter, referred to as `ABSs`), among hydraulic brake systems
installed in vehicles, for periodically intermitting braking hydraulic
pressure transmitted to wheels and preventing slip of wheels. Such
ABSs for vehicles include many solenoid valves, which are installed
on the path of a hydraulic line connecting a master cylinder and
a wheel cylinder or a hydraulic line returned from the wheel, for
opening and closing the channel of a fluid so as to control the
braking hydraulic pressure.
[0006] FIG. 1 illustrates a normal closed type solenoid valve 110.
As shown in FIG. 1, the normal closed type solenoid valve 110 comprises
a coil 112 wound on a bobbin 111 for forming an electromagnetic
field when current is applied to the coil 112, a coil case 113 having
a hollow cylindrical shape provided with an opened surface for surrounding
the coil 112, and a flux ring 114 having a disk shape for covering
the opened surface of the coil case 113. The normal closed type
solenoid valve 110 opens its channel only when power is supplied
to the coil 112.
[0007] In the solenoid valve 110, a sleeve 121 having a cylindrical
shape provided with both opened surfaces is installed in the central
area of the coil case 113, a magnet core 122 is fixedly inserted
into the upper opened surface of the sleeve 121, and an armature
123 having a designated diameter is inserted into the lower opened
surface of the sleeve 121 such that the armature 123 is separated
from the magnet core 122 by a designated interval and moves up and
down. The armature 123 interacts with the electromagnetic field
formed by the coil 112, thereby moving up and down.
[0008] A plunger 124 having a rod shape with a diameter smaller
than that of the armature 123 is formed integrally with the lower
end of the armature 123, and moves up and down together with the
movement of the armature 123. A spherical member 124a is formed
on the lower end of the plunger 124.
[0009] A valve housing 126 is placed around the outer periphery
of the plunger 124. A through hole 125 is formed through the central
portion of the valve housing 126 in a longitudinal direction so
that the plunger 124 is inserted into the valve housing 125. An
oil entry route 127 is formed in the side surface of the valve housing
126, and a sheet portion 129 provided with an oil exit route 128
opened and closed by the spherical member 124a of the plunger 124
is installed in the lower portion of the through hole 125.
[0010] A return spring 130 is installed between the armature 123
and the magnet core 122, and returns the armature 123 to the sheet
portion 129. A spring receiving groove 123a having a designated
diameter for receiving the return spring 130 is formed in the upper
end of the armature 123. Here, non-described reference numeral 131
represents a modulate block, into which the valve housing 126 is
fixedly inserted.
[0011] Now, the operation of the above-described conventional solenoid
valve 110 will be described in detail. When an electromagnetic field
is generated by applying current to the coil 112, magnetic flux
flows along the coil case 113, the flux ring 114, the armature 123,
and the magnet core 122, and the armature 123 and the plunger 124
move in the opposite direction of the movement of the sheet portion
129 against the elastic force of the return spring 130, thereby
opening the oil exit route 128. Thereafter, when the current applied
to the coil 112 is shut off, the armature 123 and the plunger 124
move toward the sheet portion 129 by means of the elastic force
of the return spring 230, thereby closing the oil exit route 128.
[0012] FIG. 2 illustrates a normal opened type solenoid valve 210.
As shown in FIG. 2, the normal opened type solenoid valve 210 comprises
a coil 212 wound on a bobbin 211 for forming an electromagnetic
field when current is applied to the coil 212, a coil case 213 having
a hollow cylindrical shape provided with an opened surface for surrounding
the coil 212, and a flux ring 214 having a disk shape for covering
the opened surface of the coil case 213. The normal opened type
solenoid valve 210 closes its channel only when power is supplied
to the coil 212.
[0013] In the solenoid valve 210, a sleeve 221 having a cylindrical
shape is installed in the central area of the coil case 213, and
the inner diameter of the lower end of the sleeve 221 is expanded.
A magnet core 222 is fixedly inserted into the upper end of the
sleeve 221, and an armature 223 having a designated diameter is
inserted into a lower opening of the sleeve 221 such that the armature
223 is separated from the magnet core 222 by a designated interval
and moves up and down. The outer diameter of the lower end of the
armature 223 is expanded corresponding to the expanded inner diameter
of the sleeve 221, and the lower end of the armature 223 is stepped.
The armature 223 interacts with the electromagnetic field formed
by the coil 212, thereby moving up and down.
[0014] A receiving groove 225 for receiving a spring 230 for assisting
the returning of the armature 223 is formed in the central portion
of the upper portion of the armature 223. One end of the spring
230 is supported by the magnet core 222, and the other end of the
spring 230 is supported by the armature 223. A plunger 224 having
a rod shape with a diameter smaller than that of the armature 223
is formed integrally with the lower end of the armature 223, and
moves up and down together with the movement of the armature 223.
[0015] A valve sheet 229, which is separated from the lower end
of the plunger 224 by a designated interval and has a channel formed
therein and opened upper end lower portions, is fixedly installed
in the valve housing 226.
[0016] The outer wall of the valve housing 226 is stepped, and
sealing members are formed on both portions (portions "B")
of the outer wall contacting a modulate block 234. An oil filter
233 is installed on the inner surface of the lower end of the valve
housing 226, an orifice pot 232 is installed on the inner surface
of the oil filter 233, and a check valve 232 is installed at one
side of the inner part of the oil filter 233.
[0017] Now, the operation of the above-described conventional solenoid
valve 210 will be described in detail. When an electromagnetic field
is generated by applying current to the coil 212, magnetic flux
flows along the coil case 213, the flux ring 214, the armature 223,
and the magnet core 222, and the armature 223 and the plunger 224
move in the opposite direction of the movement of the valve sheet
229 against the elastic force of the return spring 230, thereby
opening the oil exit route 228. Thereafter, when the current applied
to the coil 212 is shut off, the armature 223 and the plunger 224
move toward the valve sheet 229 by means of the elastic force of
the return spring 230, thereby closing the oil exit route 228.
[0018] The above-described conventional solenoid valves 110 and
210 fix and seal the valve housings 126 and 226 to the modulate
blocks 131 and 234 using the sealing members (portions "A"
and "B") or by processing portions "C" of the
housings 126 and 226, thereby having reduced assembling efficiency
and endurance. Further, in case that portions of the valve housings
126 and 226 are processed to a pocket shape and fixed to the modulate
blocks 131 and 234 by means of steel deformation, the valve housings
126 and 226 are deformed and foreign substances are generated, thereby
causing deterioration of the quality of the solenoid valves 110
and 210.
SUMMARY OF THE INVENTION
[0019] Therefore, an aspect of the invention is to provide a solenoid
valve for a brake system, which prevents the deformation of an assembled
structure thereof and the generation of foreign substances, and
has improved assembling efficiency and quality.
[0020] In accordance with one aspect, the present invention provides
a solenoid valve for a brake system comprising: a coil for forming
an electromagnetic field when current is applied thereto; a sleeve
having a cylindrical shape and passing through the central portion
of the coil; an armature, inserted into one end of the sleeve, vertically
moving by means of the electromagnetic field formed by the coil;
a valve housing, for accommodating the armature, inserted into one
end of the sleeve and provided with an oil route opened and dosed
by the armature; a magnet core fixed to the other end of the sleeve
and separated from the armature by a designated interval; a return
spring for returning the armature to the oil route when current
is not applied to the coil; and a filter fixed to the outer circumference
of the lower part of the valve housing by press fit.
[0021] The filter may be formed in a mesh structure by injection
molding.
[0022] The filter may be inserted into a modulate block such that
both sides of upper and lower ends of the filter are fixed and sealed
into the modulate block.
[0023] The valve housing may include: a through hole formed through
the central portion of the valve housing; first projecting parts
formed on both portions of the outer circumference of the valve
housing; and second projecting parts, each of which has an inclined
plane.
[0024] A modulate block, into the valve housing is inserted, may
include: a through hole formed through the central portion of the
modulate block for receiving the valve housing; and indentations
in a stepped structure corresponding to the second projecting parts
of the valve housing.
[0025] A part of the modulate block may be deformed, when the valve
housing is inserted into the modulate block, to fix and seal the
outer circumference and the upper end of the valve housing.
[0026] A plurality of protrusions having a stepped surface may
be formed on the surface of the armature contacting the magnet core.
[0027] In accordance with another aspect, the present invention
provides a solenoid valve for a brake system, comprising: a sheet
portion including a through hole formed in a longitudinal direction
through the central portion thereof, and a check ball for introducing
and discharging a fluid therethrough; a valve housing having an
inner diameter with a stepped structure for receiving the sheet
portion; an armature, installed in the valve housing, moving up
and down and having a circular sealing structure for opening and
closing an inlet of the sheet portion when power is applied thereto
and released therefrom; a sleeve installed outside the valve housing
and a magnet core; a return spring for returning the armature to
its original position; and a modulate block, into which the valve
housing is inserted, wherein the valve housing is installed in a
longitudinal direction in the sleeve such that a front end of the
valve housing is separated from the magnet core by a designated
interval.
[0028] The valve housing may include: a through hole formed through
the central portion of the valve housing; first projecting parts
formed on both portions of the outer circumference of the valve
housing; and second projecting parts, each of which has an inclined
plane.
[0029] A filter may be installed on the outer circumference of
the lower part of the valve housing below the first and second projecting
parts such that the filter is fixed to the modulate block by press
fit for sealing the inside of the valve.
[0030] The modulate block, into the valve housing is inserted,
may include: a through hole formed through the central portion of
the modulate block for receiving the valve housing; and indentations
in a stepped structure corresponding to the second projecting parts
of the valve housing.
[0031] The filter may be formed in a mesh structure by injection
molding.
[0032] The filter may be inserted into the modulate block such
that upper and lower ends of the filter are fixed and sealed into
the modulate block.
[0033] The modulate block may be deformed, when the valve housing
is assembled with the modulate block, to fix and seal the valve
housing, and the end of the outer circumference of the valve housing
may be stepped and provided with a chamber.
[0034] One end of the return spring may be supported by the sheet
portion and the other end of the return spring may be supported
by the armature.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] These and/or other aspects and advantages of the invention
will become apparent and more readily appreciated from the following
description of the embodiments, taken in conjunction with the accompanying
drawings in which:
[0036] FIG. 1 is a cross-sectional view of a conventional solenoid
valve for a brake system;
[0037] FIG. 2 is a cross-sectional view of another conventional
solenoid valve for a brake system;
[0038] FIG. 3 is a cross-sectional view of a solenoid valve for
a brake system in accordance with a first embodiment of the present
invention;
[0039] FIG. 4 is an enlarged view of the portion "D"
of FIG. 3; and
[0040] FIG. 5 is a cross-sectional view of a solenoid valve for
a brake system in accordance with a second embodiment of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] Reference will now be made in detail to the embodiments
of the present invention, an example of which is illustrated in
the accompanying drawings, wherein like reference numerals refer
to like elements throughout. The embodiments are described below
to explain the present invention by referring to the figures.
[0042] FIG. 3 is a cross-sectional view of a solenoid valve 150
for a brake system in accordance with a first embodiment of the
present invention. The solenoid valve 150 of this embodiment is
a normal opened type solenoid valve, which opens its channel only
when power is supplied thereto.
[0043] As shown in FIG. 3, the solenoid valve 150 of the first
embodiment of the present invention comprises a coil 152 wound on
a bobbin 151 for forming an electromagnetic field when current is
applied to the coil 152, a coil case 153 having a hollow cylindrical
shape provided with an opened surface for surrounding the coil 152,
and a flux ring 154 made of a disk-shaped magnetic material for
covering the opened surface of the coil case 153. Thereby, the electromagnetic
field formed by the coil 152 flows along a closed circuit formed
by the coil case 153 and the flux ring 154.
[0044] A through hole is formed through the central portion of
the solenoid valve 150 in a longitudinal direction. The solenoid
valve 150 further comprises a valve housing 165 including an oil
entry route 167 formed in the side surface thereof for entering
oil into the solenoid valve 150 therethrough, and an oil exit route
128 and an orifice 169 formed in the lower end thereof for discharging
the oil to the outside therethrough.
[0045] An armature 163 having a cylindrical shape is inserted into
the through hole of the valve housing 165 and the central portion
of the coil case 153 so that the armature 163 interacts with the
electromagnetic field formed by the coil 152 and moves up and down,
and a spherical member 164 for opening and closing the oil exit
route 128 is installed on the lower end of the armature 163.
[0046] A sleeve 161 having a cylindrical shape provided with upper
and lower opened ends surrounds the outer circumferences of the
valve housing 165 and the armature 163. The valve housing 165 is
fixedly inserted into the lower opened end of the sleeve 161, and
a magnet core 162 is fixedly inserted into the upper opened end
of the sleeve 161 such that the magnet core 162 is separated from
the armature 163 by a designated interval. As shown in FIG. 4, a
plurality of protrusions, each of which has a stepped surface, are
formed on the upper end of the armature 163, i.e., the surface "D"
of the armature 163 contacting the magnet core 162.
[0047] A return spring 170 for returning the armature 163 to the
oil exit route 168 of the valve housing 165 is installed between
the armature 163 and the magnet core 162. The return spring 170
is mounted in a groove formed in the central portion of the upper
surface of the armature 163. One end of the return spring 170 is
supported by the magnet core 162, and the other end of the return
spring 170 is supported by the armature 163.
[0048] First projecting parts 165a are respectively formed on both
portions of the outer circumference of the valve housing 165 below
a stationary part 165b of the valve housing 165 fixed by the sleeve
161, and have a stepped structure. Second projecting parts 165c
are respectively formed below the first projecting parts 165a.
[0049] A modulate block 171, to which the valve housing 165 is
fixed, includes stepped indentations 171a corresponding to the first
and second projecting parts 165a and 165c of the valve housing 165.
When the valve housing 165 is assembled with the modulate block
171, a portion of the modulate 171 is deformed so that the outer
circumference including the upper end. i.e., the portion "E"
of the valve housing 165 is fixed to the inner circumference of
the modulate block 171, and is sealed.
[0050] A filter 166 formed in a mesh structure by injection molding
surrounds the portion of the valve housing 165 below the first and
second projecting parts 165a and 165c. When the filter 166 is assembled
with the modulate block 171, the outer circumferences of the portion
"F" and the portion "G" of the filter 166 are
deformed and fixed to the inner circumference of the modulate block
171 by press fit, and are then sealed.
[0051] Now, the operation of the above-described solenoid valve
150 will be described. When an electromagnetic field is generated
by applying current to the coil 152, magnetic flux flows along the
coil case 153, the flux ring 154, the armature 163, and the magnet
core 162, and the armature 163 moves in the opposite direction of
the oil exit route 168 of the valve housing 165 against the elastic
force of the return spring 170, thereby opening the oil exit route
168. Subsequently, when the current applied to the coil 152 is shut
off, the armature 163 returns to its original position by the elastic
force of the return spring 170, thereby closing the oil exit route
168.
[0052] Hereinafter, with reference to FIG. 5, a solenoid valve
for a brake system in accordance with a second embodiment of the
present invention will be described in detail.
[0053] FIG. 5 is a cross-sectional view of a solenoid valve 250
for a brake system in accordance with a second embodiment of the
present invention. The solenoid valve 250 of this embodiment is
a normal opened type solenoid valve, which closes its channel when
power is supplied thereto.
[0054] As shown in FIG. 5, the solenoid valve 250 of the second
embodiment of the present invention comprises a coil 252 wound on
a bobbin 251 for forming an electromagnetic field when current is
applied to the coil 252, a coil case 253 having a hollow cylindrical
shape provided with an opened surface for surrounding the coil 252,
and a flux ring 254 made of a disk-shaped magnetic material for
covering the opened surface of the coil case 253. Thereby, the electromagnetic
field formed by the coil 252 flows along a closed circuit formed
by the coil case 253 and the flux ring 254.
[0055] A through hole is formed through the central portion of
the solenoid valve 250 in a longitudinal direction, and the front
end of the through hole is closed by a sleeve 261. A magnet core
262, which moves up and down when power is applied thereto, is installed
in the sleeve 261. An armature 270 and a valve housing 269 are installed
below the magnet core 262.
[0056] A sheet portion 267, having a through hole formed through
the central portion thereof and a check ball 264 for controlling
the introduction and discharge of a fluid therethrough, is installed
in the valve housing 269. The armature 270, which moves together
with the movement of the magnet core 262 and has a circular sealing
structure for opening and closing the inlet of the sheet portion
267, is installed in the valve housing 269. A return spring 258
for returning the armature 270 to the original position is installed
between the armature 270 and the sheet portion 267.
[0057] The outer circumference of the magnet core 262 of the valve
housing 269 is fixed to the sleeve 261, and the lower end of the
valve housing 269 is fixed to a modulate block 271. When the valve
housing 269 is assembled with the modulate block 271, the modulate
block 271 is deformed and fixed to the valve housing 269. The end
of the valve housing 269 is stepped, and provided with a chamber.
[0058] One end of the valve housing 269 is fixed to the sleeve
261, and the other end of the valve housing 269 is fixed into the
modulate block 271. First projecting parts 265a are respectively
formed on both portions of the outer circumference of the valve
housing 269 fixed into the modulate block 271 and have a stepped
structure, and second projecting parts 265c are respectively formed
below the first projecting parts 165a.
[0059] The modulate block 271, into which the valve housing 265
is fixed, includes stepped indentations 271a corresponding to the
first and second projecting parts 265a and 265c of the valve housing
265. When the valve housing 265 is assembled with the modulate block
271, a portion of the modulate block 271 is deformed to fix and
seal the outer circumference and the top end (portion "H")
of the valve housing 265.
[0060] A filter 266 formed in a mesh structure by injection molding
surrounds the portion of the valve housing 265 below the first and
second projecting parts 265a and 265c. When the filter 266 is assembled
with the modulate block 271, the outer circumference of the filter
166 is deformed and fixed to the inner circumference of the modulate
block 171 by press fit, and is then sealed (portion "I"
and portion "J").
[0061] Now, the operation of the above-described solenoid valve
250 will be described. When current is applied to the coil 252,
which is assembled with the solenoid valve 261, magnetic force is
generated. The magnetic force generates attractive force between
the valve housing 269 and the magnet core 262. Since the valve housing
269 is fixed to the modulate block 271, the magnetic core 262 moves
toward the valve housing 269, thereby pushing the armature 270.
The armature 270 moves and contacts the sheet portion 267, thereby
shutting off the channel connecting the inlet and the outlet. When
current is released from the coil 252, the armature 270 and the
magnet core 262 return to their original positions by the return
spring 258 positioned between the armature 270 and the sheet portion
267.
[0062] As apparent from the above description, the present invention
provides a solenoid valve for a brake system, in which a filter
formed in a mesh structure by injection molding is installed on
the outer circumference of the lower part of a valve housing below
projecting parts, thereby causing the outer circumference of the
filter to be deformed so as to decrease the pressing force of the
filter, when the filter is assembled with a modulate block, so that
the filter is easily assembled with the modulate block, not requiring
a sealing member outside the valve housing so that the production
costs of solenoid valve products are reduced, and preventing the
generation of foreign substances between the valve housing and the
modulate block when the armature vertically moves.
[0063] Although embodiments of the invention have been shown and
described, it would be appreciated by those skilled in the art that
changes may be made in these embodiments without departing from
the principles and spirit of the invention, the scope of which is
defined in the claims and their equivalents.
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