Electricity: magnetically operated switches – magnets – and electr – Magnets and electromagnets – With magneto-mechanical motive device
Reexamination Certificate
2000-01-18
2001-02-06
Donovan, Lincoln (Department: 2832)
Electricity: magnetically operated switches, magnets, and electr
Magnets and electromagnets
With magneto-mechanical motive device
C335S251000, C251S129140
Reexamination Certificate
active
06184766
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a solenoid valve, and more particularly, to a solenoid valve which makes it possible to switch over the channel by driving by an electromagnetic unit in response to an electric signal.
BACKGROUND ART
FIG. 7
is a sectional view illustrating an non-energizing state of a conventional normally closed type three-way solenoid valve.
In
FIG. 7
, a bobbin
1
is a formed resin inserted with a plate
22
made of a magnetic material, and terminals
6
and
7
, provided with a coil winding section
1
g
. Further, the bobbin
1
is provided with an input port
2
, an output port
3
and a discharge port
4
, and has O-ring grooves
1
a
and
1
b
receiving O-rings
9
and
10
for preventing oil leakage.
A plunger
29
is made of a magnetic material, guided by the bobbin
1
and vertically slidably arranged. A bush
23
is made of a magnetic material, and inserted on one end side of the bobbin
1
so as not to be in contact with the plunger
29
. Further, a case
11
is made of a magnetic material, attached to the outer periphery of the bobbin
1
having a coil
12
wound on the coil winding section
1
g
, and is secured to the plate
22
by caulking. A holder
24
made of a magnetic material is provided between the case
11
and the bush
23
, and ensures magnetic association of the two. A non-magnetic holder
25
is attached to the one end side of the bobbin
1
so as to secure internal parts of the solenoid.
A ball
13
is inserted into the input port
2
at the other end of the bobbin
1
, and further a bush
14
is inserted therein. Going off of the ball
13
is prevented by heat-caulking a caulking section
1
c
of the bobbin. The plunger
29
is provided integrally with a valve rod
29
a
for pushing the ball
13
attached to the input port
2
, and the base portion of the valve rod
29
a
forms a valve section
29
b.
A magnetic circuit is formed with the case
11
, the plate
22
, the plunger
29
, the bush
23
and the holder
24
.
In the conventional solenoid valve
100
having the configuration described above, in a non-energizing state of the coil
12
, the ball
13
is seated onto a valve seat
1
e
under a pressure of a fluid acting on the input port
2
, and the fluid does not flow in from the input port
12
. Movement of the ball
13
seated onto the valve seat
1
e
pushes up the valve rod
29
a
. As a result of upward movement of this valve rod
29
a
, i.e., the plunger
29
, the valve section
29
b
leaves a valve seat
1
d
, and communication is established between the output port
3
and the discharge port
4
.
When energizing the coil
12
, magnetism is supplied to the magnetic circuit composed of the case
11
, the plate
22
, the plunger
29
, the bush
23
and the holder
24
, and the plunger
29
is magnetically attracted toward the plate
22
. This magnetic attraction overcomes the pressure of the fluid acting via the ball
13
and the plunger
29
, and the plunger
29
moves toward the plate
22
. Under the effect of this movement of the plunger
29
, the valve section
29
b
is seated onto the valve seat
1
d
, and at the same time, the valve rod
29
a
of the plunger
29
pushes the ball
13
. The ball
13
thus leaves the valve seat
1
e
. The output port
3
is thus separated from the discharge port
4
, and there is achieved communication between the input port
2
and the output port
3
.
In the conventional solenoid valve
100
, a portion generating an electromagnetic force and a valve portion controlling the fluid are integrally configured. It is therefore impossible to achieve common parts among solenoid valves of different specifications, leading to a higher cost.
DISCLOSURE OF THE INVENTION
The present invention was developed to solve the foregoing problems and has an object to provide a solenoid valve having a configuration in which the portion generating an electromagnetic force can be separated from the valve portion controlling the fluid, which permits improvement of general-purpose property of parts and achievement of a lower cost.
The invention provides a solenoid valve having an input port, an output port and a discharge port, in which a channel is switched over by driving by an electromagnetic unit, comprising a cylindrical bobbin having a center hole pierced therein and a coil wound on the outer periphery thereof; a housing having the input port, the output port and the discharge port, arranged on one end side of the bobbin; a plate made of a magnetic material, provided between the bobbin and the housing; a case, made of a magnetic material, having a bottom plate provided with a throughhole and a plurality of claws extending from ends of the bottom plate in a direction at right angles to the main surface of the bottom plate, covering the bobbin from the other end of the bobbin so as to align the center of the throughhole with the center hole of the bobbin, and integrally securing the bobbin, the plate and the housing by caulking the claws with the plate and housing; a plunger, made of a magnetic material, having a cylindrical shape with a bottom, inserted into the center hole of the bobbin with the bottom directed toward the plate, which is reciprocally arranged in the axial direction of the bobbin as the outer peripheral surface on the opening side of the plunger faces on the inner wall surface of the throughhole of the case, and is magnetically attracted toward the plate by a magnetic attracting force produced during energizing of the coil; a ball, arranged in the housing, for switching over the channel by the utilization of a difference between the magnetic attracting force and pressure of a fluid acting via the input port; and a valve rod made of a non-magnetic material, arranged in the housing, for transmitting the magnetic attracting force to the ball under pressing by the plunger magnetically attracted toward the plate; wherein an engaged section is formed on an end face on the housing side of the bobbin, an engaged section is formed on an end face of the bobbin side of the housing, an engaging section for positioning the bobbin and an engaging section for positioning the housing are formed on the plate, and a relative relationship between the bobbin and the housing is maintained by engaging these engaging sections with the engaged sections of the bobbin and the housing.
REFERENCES:
patent: 5597013 (1997-01-01), Ushakov
patent: 5651391 (1997-07-01), Connolly et al.
patent: 5752689 (1998-05-01), Barkhimer et al.
patent: 5915416 (1999-06-01), Okazaki et al.
patent: 5950984 (1999-09-01), Anderson et al.
patent: 61-278675 (1986-12-01), None
patent: 8-105563 (1996-04-01), None
patent: 8-226566 (1996-09-01), None
patent: 9-79412 (1997-03-01), None
Himei Hidekazu
Kojima Takao
Donovan Lincoln
Mitsubishi Denki & Kabushiki Kaisha
Nguyen Tuyen T.
Sughrue Mion Zinn Macpeak & Seas, PLLC
LandOfFree
Solenoid valve does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Solenoid valve, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Solenoid valve will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2581132