JPH0720461Y2 - solenoid valve - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] This invention operates a spool valve by exciting an electromagnetic coil, and changes the positional relationship with a sleeve in which the spool valve is inserted in a retractable manner. This relates to a solenoid valve that performs switching operation of oil passages, etc., especially when the input fluid is at high pressure and high flow rate, so as not to apply unbalanced pressure to the spool valve that prevents smooth movement of the spool valve. It concerns a solenoid valve.

[Conventional technology]

FIG. 4 is a cross-sectional view showing a conventional solenoid valve disclosed in, for example, Japanese Patent Laid-Open No. 56-76777, and (1) shows cast iron that accommodates each constituent member of the solenoid valve and forms a magnetic circuit. And a cap body (3) made of a non-magnetic material, together with a cap (3) made of a non-magnetic material, is an end plate that closes one end opening of the case body (1) to form a magnetic circuit. A fluid escape hole (8a) is formed substantially in the center of the cap (3) which is superposed with the gap (G) with a gap (G). (4) is a core fixed at a predetermined position in the case body (1) together with an exciting coil (7) wound around a bobbin (6) made of an insulating material. It is provided for sucking the plunger (5) that presses the rod (10) that can move back and forth in the central portion in a predetermined direction.

(8) is a lead wire which is held by an insulating bush (9) attached to a predetermined position of the bobbin (6) and which energizes the exciting coil (7), and (12) and (13) are the case body ( 1) A plurality of fluid flow holes (19a) (19b) respectively corresponding to a fluid input hole (16), a fluid output hole (17), and a fluid discharge hole (18) provided at one side with a predetermined interval. ) And (19c) are formed in the first and second sleeves, and (11) is a spool valve inserted in both sleeves (12) and (13) so as to be able to move back and forth. A valve body (11a) having a trapezoidal cross section is formed in the portion, and narrow diameter portions (11b) (11b) are formed on both sides thereof. Then, the valve seats (12a) (18a) on both sides of the fluid flow hole (19b) formed by the first and second sleeves (12) (13).
The taper part (11L) formed on both sides of the valve body (11a)
The fluid input hole (1R)
The fluid flowing in from 6) is guided to the fluid output hole (17), and the fluid in the fluid output hole (16) is discharged from the fluid discharge hole (18).

(15) is a recess (15a) formed in the center of the free end side of the spool valve (11) and an adjusting screw (14) screwed into the center of the free end side of the case body (1). A spring interposed between the spring (15) and the adjusting screw (14) for constantly pressing the spool valve (11) toward the rod (10) with a predetermined pressure. Is for adjusting the pressure of this spring (15).

Since the solenoid valve of this invention is configured as described above,
When the excitation coil (7) is deenergized, the pressing force of the spring (15) causes the taper portion (11L) of the valve body (11a) of the spool valve (11) to move to the sleeve ( Since the valve seat (13a) of (13) is engaged with a predetermined pressure, the fluid discharge hole (18) is closed, and the fluid flowing from the fluid input hole (16) flows through the fluid output hole (17) to the outside. Is supplied to.

Next, when the exciting coil (7) is energized, the plunger (5) is attracted to the core (4), so that the rod (10) resists the elastic force of the spring (15). The valve seat (12) of the taper part (11R) sleeve (12) of the valve body (11a) of the spool valve (11) presses the valve seat (12).
Since it is engaged with a) at a predetermined pressure, the fluid input hole (16) is closed, and the pressure fluid in the fluid output hole (17) connected to the outside is discharged from the fluid discharge hole (18) to the outside, so-called normally open. Operates as a three-way solenoid valve of the type.

[Problems to be solved by the invention]

The spool valve (11) in the conventional solenoid valve described above is well balanced at the time of static pressure where the fluid does not flow inside, but when the fluid flowing in the solenoid valve has a high pressure and a high flow rate, the sleeve ( 12) (13) valve seat (12a) (1
The valve body (11a) of the spool valve (11) that engages with 3a) has a trapezoidal cross-section with tapered portions (11L) (11R), and is formed on both sides of the valve body (11a). Since the fluid passage is the thin portion (11b) (11b) having a flat end, the high pressure and high flow rate fluid flowing around the spool valve (11) does not flow smoothly, and the spool valve (11) On the other hand, there is a drawback that the spool valve (11) does not move smoothly because unbalanced fluid pressure is applied.

The present invention has been made in view of this point, and an object thereof is to provide an electromagnetic valve having a spool valve that smoothly moves even when a fluid having a high pressure and a high flow rate flows.

[Means for solving problems]

A solenoid valve according to the present invention has a shape of a valve element of a spool valve that reciprocates in a sleeve and a shape of a small diameter portion that is a fluid flow passage of the spool valve, even if high pressure and high flow rate fluid flows. It is a hydrodynamic shape that does not apply unbalanced fluid pressure to the spool valve.

[Action]

In this invention, the unbalanced fluid pressure is not applied to the spool valve due to the shape of the valve body of the spool valve and the shape of the small diameter portion which is the fluid flow passage of the spool valve, so that the spool valve always moves smoothly back and forth. However, the operation is always reliable.

[Example of device]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view showing a spool valve and a sleeve of a solenoid valve according to an embodiment of the present invention. The same reference numerals as those of the conventional one (FIG. 4) described above are the same constituent members, and the description thereof will be omitted.

(11A) is a valve body formed in a maximum diameter portion approximately in the middle of the spool valve (11), and both sides of this valve body (11A) are right-angled walls (11X) perpendicular to the axial direction of the spool valve (11). (11Y) is formed, and this right-angled wall (11X) (11Y) is
2) An annular poppet valve is formed in (13) so as to make substantially surface contact with valve seats (12A) (13A) formed substantially at right angles to the axial direction. As shown in FIG. 2 and FIG. 3, (11Z) is circumferentially spaced 180 ° from each other at the free side ends of the small diameter portions (11b) and (11b) of the spool valve (11). Formed above the sleeve (1
2) A plurality of pressure relief slits that always correspond to the fluid circulation holes (19a) and (19c) of (13).

Since the spool valve (11) in the solenoid valve of the present invention is configured as described above, the fluid that flows in from the fluid input hole (16) of the case body (1) and is sent out to the fluid output hole (17), And fluid output hole (17) to fluid discharge hole (18)
Even if the fluid discharged to the
The fluid flowing into the small diameter parts (11b) (11b) of the spool valve (11) always causes the pressure relief slit (11) of the spool valve (11).
Z) and also the right angle wall (11X) of the spool valve (11)
(11Y) and valve seats (12A) (13A) are large enough to prevent the working fluid from escaping suddenly due to the size of the area, so the shock between the spool valve (11) and sleeve (12) (13) is absorbed. The spool valve (11) is relaxed and unbalanced fluid pressure is not applied.

[Effect of device]

According to this invention, a right-angled wall is formed on both sides of a valve body having the maximum diameter of a spool valve that reciprocates in a sleeve, and a poppet valve is formed between the right-angled wall and an opposing valve seat. Since the pressure relief slit is formed in the small diameter part that is the fluid flow passage, the impact of high pressure and high flow rate fluid is absorbed and relaxed by these, and unbalanced fluid pressure is not applied to the spool valve. The spool valve always moves smoothly back and forth, and it is possible to provide a solenoid valve that operates reliably.

[Brief description of drawings]

1 is a sectional view showing a spool valve and a sleeve of a solenoid valve according to an embodiment of the present invention, FIG. 2 is a sectional view of a spool valve, and FIG. 3 is a sectional view taken along line (III)-(III) of FIG. FIG. 4 is a sectional view showing a conventional solenoid valve. In the figure, (1) is the case body, (4) is the core,
(5) is a plunger, (7) is an exciting coil, (11) is a spool valve, (11A) is a valve element, (11b) is a small diameter portion, (11X).
(11Y) right angle wall, (11Z) pressure relief slit, (12)
(13) is a sleeve, (12A) and (13A) are valve seats, (16) is a fluid input hole, (17) is a fluid output hole, and (18) is a fluid discharge port. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (2)

[Scope of utility model registration request] 1. A plunger, at a predetermined position in the case body,
In a housing containing an exciting coil, a sleeve and a spool valve, right-angled walls are provided on both sides in the axial direction of the valve body of the maximum diameter portion of the spool valve that reciprocates in the sleeve, and a valve seat of the sleeve facing the right-angled wall. Is formed substantially perpendicular to the axial direction to form an annular poppet valve between the spool valve and the sleeve, and a pressure relief slit is formed in the small diameter portion of the spool valve corresponding to the fluid passage. Solenoid valve characterized by. 2. A utility model registration claim in which a case body is provided with a fluid input hole, a fluid output hole, and a fluid discharge hole corresponding to the valve body and the small diameter portion of the spool valve. The solenoid valve described.