JPH0330751B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a solenoid valve used in an industrial machine that utilizes fluid pressure or vacuum pressure.

[Prior Art] In conventional solenoid valves, when the fixed core attracts the movable core by excitation of the excitation coil, the movable core is also attracted in the radial direction by the excitation coil, and the attraction acts strongly. Since the outer circumferential wall slides in contact with the inner surface of the cylindrical body made of a non-magnetic material inside the excitation coil, the friction between the movable core and the cylindrical body causes a large amount of wear. I couldn't use it for a while.

In addition, in order to reduce this friction, it has been considered to coat the outer peripheral wall of the movable core with a highly lubricating synthetic resin coating with a small friction coefficient, but this coating also wears out due to the sliding of the movable core. There was a problem in that the electromagnetic valve could not be used for a long time with high frequency operation because of peeling.

[Problems to be Solved by the Invention] The present invention allows pressure fluid flowing through a solenoid valve to flow into the gap between the outer peripheral wall of a movable core and an outer peripheral fixed portion surrounding it, and directs this pressure fluid to the outer peripheral wall of the movable core. By supporting the movable core with this pressure fluid, it is possible to prevent contact between the outer peripheral wall of the movable core and the fixed part surrounding it, reduce wear of the movable core, and extend the life of the solenoid valve. The purpose is to increase

[Means for Solving the Problems] In order to solve the above problems, the present invention provides an inflow port and an outflow port for pressure fluid, a passageway that communicates both ports, a valve seat formed in the passageway, and a valve seat formed in the passageway. In a solenoid valve comprising an electromagnetic operating part that opens and closes, a part of the pressure fluid flowing through the electromagnetic valve is directed to one of the outer peripheral wall of the movable core of the electromagnetic operating part and the outer peripheral fixed part surrounding it to the other opposing side. It is characterized by having a plurality of rows of radial outflow holes in the circumferential direction for holding the movable iron core in a non-contact state with the outer peripheral fixing part by allowing the movable iron core to flow out.

[Operation] When the movable core slides due to the suction force of the fixed core, the flow from the multiple rows of outflow holes provided in either the outer circumferential wall of the movable core or the fixed part surrounding it toward the other opposing side. A part of the pressure fluid flowing through the solenoid valve flows out in the radial direction, and the movable core is supported by the air bearing effect of these radial pressure fluids.
To prevent contact between the outer peripheral wall of the movable core and the fixed part surrounding it.

[Embodiment] Figures 1 to 3 show a first embodiment of the present invention, in which a valve body 1 is provided with an inflow port 2 and an outflow port 3, which face an electromagnetic operating section to be described later. A valve chamber 4 is recessed in the surface, the inflow port 2 is communicated with the valve chamber 4 by a passage 5 in the valve body 1, and the outflow port 3 is communicated with the valve chamber 4 by a passage 6 in the valve body 1. It communicates with the valve seat 4a of the chamber 4.

On the other hand, in the electromagnetic operation section, magnetic frames 13a and 13b having a U-shaped cross section and covering the outside of the bobbin 12 made of a non-magnetic material around which the excitation coil 11 is wound have holes provided at both ends of the magnetic frames 13a and 13b. The fixed core 15, which is inserted and fixed into the hole 14 of the bobbin 12 through the hole in one bent part, has a reduced diameter part formed near its suction end, and the reduced diameter part has an opening in the diametrical direction. A cross-shaped distribution hole 15a is provided therein, and a plurality of ejection holes 15b, .

A connecting ring 16 is fixed to the other end of the magnetic frames 13a, 13b, and by screwing the connecting ring 16 and the valve body 1 with a sealing member interposed, the magnetic frames 13a, 13b It is connected to the valve body 1. In addition, the magnetic frames 13a and 13b
In order not to reduce the insulation function of the exciting coil 11, its inner and outer peripheries are molded with synthetic resin.

Hole 14 of the bobbin 12, magnetic frames 13a, 13
A guide tube 18 made of a non-magnetic material is fitted into the inner surface of the hole provided in the bent portion of b and the hole of the connecting ring 16, and the guide tube 18 is made of a non-magnetic material and passes through these holes. It is fixed to the circumferential surface of the fixed iron core 15, and the other end is expanded and abutted against the end surface of the connecting ring 16. Further, a support tube 22 is attached to the reduced diameter portion of the fixed iron core 15 with a gap forming a communication portion 21 with the guide tube 18.
is supported by the valve body 1 so as to surround the valve seat 4a of the valve chamber 4 at its other end.

The support pipe 22 has a pressure fluid introduction hole 23 that opens into the passage 5 of the valve body 1 near the end on the valve body side, and has an appropriate number of outflow holes 22a, . . . in the middle part thereof. A plurality of consecutive rows of outflow holes in the axial direction are arranged at equal intervals.

A movable iron core 27 is inserted into the support tube 22 with a gap 25 between it and the support tube 22, and a movable iron core 27 is provided at one end with a valve member 26 for closing the valve seat 4a. 27 is always biased by a return spring 28 provided between a recess formed on the other end surface and the fixed iron core 15 so that the valve member 26 closes the valve seat 4a. The movable core 27 constitutes the electromagnetic operation unit 10 together with the exciting coil 11, the fixed core 15, the magnetic frames 13a and 13b, and the like.

In FIG. 1, reference numeral 29 is a conductive wire that connects the excitation coil 11 to a power source.

In the first embodiment described above, when the excitation coil 11 is not excited, the valve member 26 is moved by the return spring 28.
The valve seat 4a is closed by the valve seat 4a, but the pressure fluid from the inflow port 2 passes through the passage 5 and the pressure fluid introduction hole 23, or from the passage 5 to the communication part 21 and the outflow hole 22a, ... or the cross-shaped distribution hole. 15a and the ejection holes 15b, . . . and flows into the gap 25.

When the exciting coil 11 is excited in this state, the movable core 27 is attracted to the fixed core 15 and slides, and the valve member 26 first slightly opens the valve seat 4a. Due to the initial opening of the valve seat 4a, the fluid in the gap 25 flows from the valve seat 4a to the outflow port 3 along the outer circumferential wall of the movable core 27, and this flow flows through the outflow holes 22a, . . .
The inflow of pressure fluid from the jet holes 15b, . . . continues while the valve member 26 opens the valve seat 4a. On the other hand, the pressure fluid flowing from the pressure fluid introduction hole 23 to the valve seat 4a also flows to the outflow port 3 through the valve seat 4a.

The movable iron core 27 is held at the center of the support tube 22 by the air bearing effect caused by the inflow of pressure fluid from the outlet holes 22a, . Since the pressure fluid flows out to the outflow port 3 through the valve seat 4a, a flow of pressure fluid is formed along the outer peripheral wall of the movable core 27 through the gap 25, and the movable core 27 is moved by the flow of pressure fluid. Even if a force is applied to bring them into contact, a gas film of several microns is formed due to the fluid pressure and the contact is prevented. Prevented. In this case, if the opening area of the pressure fluid introduction hole 23 is made smaller than the opening area of the valve seat 4a, the amount of pressure fluid flowing into the gap 25 through the outflow holes 22a, etc. becomes large, so that the pressure The supporting force of the movable iron core 27 due to the flow of fluid can be increased.

When the movable iron core 27 mentioned above slides, the movable iron core 27
When the pump is pulled in the radial direction by the excitation coil 11 and tries to eccentrically move within the gap 25, the gap 25a on the eccentric side becomes narrower and the fluid pressure P ₁ in that part increases, as shown in FIG. On the other hand, as the gap 25b on the opposite side becomes wider and the fluid pressure _P2 in this area becomes lower, a force acts on the movable core 27 to return it to the concentric direction. Therefore,
Even if a force is applied to make the movable core 27 eccentric when the movable core 27 is sliding, the movable core 27 is prevented from coming into contact with the support tube 22 .

Note that when the movable core 27 is attracted to the fixed core 15 and slides, the pressure fluid flowing in from the jet holes 15b collides with the end face of the movable core 27, so that the sliding speed of the movable core 27 is reduced. Furthermore, when the gap between the movable core 27 and the fixed core 15 becomes narrower, the pressure fluid in this narrowed gap becomes resistance to the sliding movement of the movable core 27, so the sliding speed of the movable core 27 further decreases, and the fixed core 15 is fixed. The impact caused by the collision with the iron core 15 is alleviated.

Furthermore, although not shown, if an axial groove with an open inner side is provided between the outflow hole rows of the support tube 22, the above-mentioned fluid pressure P ₁ will be increased by the pressure fluid flowing inside the groove. Since the action areas of P and P ₂ can be partially divided, the above-mentioned concentric return action becomes more reliable.

4 to 6 show a second embodiment of the present invention, in which an inflow port 32 formed in a valve body 31 is communicated with a valve chamber 34 through a passage 35 and a valve seat 34a. , the outflow port 33 is the passage 36
It is communicated with the valve chamber 34 by. Further, the magnetic frame 41 is formed as an integral piece with a rectangular cross section, and the movable iron core 4 is attracted to the fixed iron core 42.
3 is directly inserted into the guide tube 18 with a gap 25 in between, without using a support tube. The movable iron core 43 is provided with a valve member 45 having a through hole 44 on one end surface thereof, and further has a pressure fluid introduction hole 46 communicating with the through hole 44 in the axial direction thereof.
The pressure fluid introduction hole 46 is opened at the end face of the movable iron core 43 by a small-diameter jet hole 47 formed at the bottom of the hole, and has an outflow hole 43a that opens radially from the pressure fluid introduction hole 46. A suitable number of rows of outflow holes are arranged in a row at equal intervals in the axial direction.

The rest of the structure of the second embodiment is the same as that of the first embodiment, but as shown in FIG.
8 can be omitted.

In the second embodiment, the through hole 44 is provided in the valve member 45.
However, since the movable iron core 43 is provided with the outflow holes 43a, ... and the ejection holes 47, the valve member 45
Even when the valve seat 34a is closed, a small amount of the pressurized fluid from the inflow port 32 flows into the movable core 4.
3 and flows out from the gap 25 to the outflow port 33. Since the force of the air pressure acting on both ends of the movable iron core 43 is approximately balanced due to the ejection of the pressurized fluid from the ejection hole 47, the return spring 28 can be omitted if the attitude of the solenoid valve is considered. The valve member 45 never opens the valve seat 34a.

On the other hand, the movable iron core 43 has its outer circumferential wall supported by the pressure fluid flowing through the above-mentioned gap 25, and therefore is located substantially concentrically with the guide tube 18 without contacting it. In this case, if the movable iron core 43 is eccentric due to some force, the first
As explained in the embodiment, the fluid pressure P ₁ in the gap 25a on the eccentric side and the fluid pressure in the gap 25b on the opposite side
Due to the acting force due to the difference with P ₂ , the movable iron core 43
returns to the concentric direction and is prevented from contacting the tube 18 (see FIG. 5).

When the excitation coil 11 is excited in the above-mentioned state, the attractive force of the fixed iron core 42 is applied to the fixed iron core 42 and the movable iron core 4.
3 and the valve member 45 opens the valve seat 34a, the pressurized fluid from the inflow port 32 is transferred to the outflow port 33.
leaks to. When the movable core 43 slides, even if the movable core 43 receives a force in the radial direction and tries to eccentrically shift, an acting force that returns the movable core 43 to the concentric direction acts to prevent the movable core 43 from coming into contact with the tube 18. What is prevented is the same as in the first embodiment.

In addition, as shown in FIG. 5, the movable iron core 43
If a groove 48 is opened in the axial direction at the middle position of each row of the plurality of rows of outflow holes 43a, . .

Further, the sliding movement of the movable core 43 is decelerated by the reaction force when the pressure fluid ejected from the jet hole 47 collides with the fixed core 42, and when the gap between the movable core 43 and the fixed core 42 further narrows, Since the pressure fluid in the narrowed gap acts as a resistance to the sliding movement of the movable core 43, the sliding speed of the movable core 43 is further reduced, and the impact caused by the collision with the fixed core 42 is alleviated. In this case, although not shown, a convex portion is formed around the ejection hole 47 of the movable iron core 43,
If a concave portion into which the convex portion is loosely inserted is formed in the fixed core 42, when the convex portion of the movable core 43 is inserted into the concave portion of the fixed core 42, the discharge passage for pressurized fluid from the ejection hole 47 will suddenly contract. After a while, moveable iron core 43
Since the speed is further reduced, the above-mentioned impact can be further alleviated.

7 and 8 show a third embodiment of the present invention, in which a valve body 51 is installed within the guide pipe 18, and only an inflow port 52 is bored, and an outflow port 53 is bored in the fixed iron core 61. The inflow port 52 is defined by a passage 55 provided in the valve body 51, and the outflow port 53 is defined by a passage 56 provided in the fixed core 61. This space is used as the valve chamber 54, and the valve chamber 54 of the passage 56 communicates with the space inside the passage 56.
The opening end to the valve seat 54a is the valve seat 54a.

The valve chamber 54 includes the guide pipe 18 and the gap 2.
5, and a movable iron core 63 having a valve member 62 at one end for closing the valve seat 54a is inserted. This movable iron core 63 has a pressure fluid introduction hole 64 opened to the passage 55 side, and an appropriate number of outflow holes 63a, which open radially from the pressure fluid introduction hole 64, are connected in the axial direction. A plurality of rows of outflow holes are arranged at equal intervals, and grooves 65, . . . are formed in the axial direction at intermediate positions of the outflow hole rows (see FIG. 8).

Moreover, the fixed iron core 61 in the movable iron core 63
A recess 66 is provided on the surface facing the recess 66, and the return spring 28 inserted into the recess 66 keeps the movable core 63 in pressure contact with the valve body 51 at all times, and the valve member 62 opens the valve seat 54a. are doing.

On the other hand, an ejection hole 58 is provided in the axial direction of the valve body 51 at a location where the end surface of the movable iron core 63 contacts, and a guide cylinder protrudes into the pressure fluid introduction hole 64 in the passage 55. 59 is formed.

In the third embodiment, when the excitation coil 11 is not excited, the return spring 28 causes the valve member 62 of the movable core 63 to open the valve seat 54a, so that the pressure fluid from the inflow port 52 is Passage 55, pressure fluid introduction hole 64, outflow hole 63a,...
It flows out from the outflow port 53 through the gap 25 and the like. Therefore, the movable iron core 63 is supported by the pressure fluid flowing through the gap 25 in its outer circumferential wall, and is positioned substantially concentrically with the guide tube 18 without contacting it.

When the excitation coil 11 is excited in the above state, the fixed iron core 61 attracts the movable iron core 63 and the valve member 62
closes the valve seat 54a and the flow of pressure fluid stops. The movable core 63 is prevented from coming into contact with the guide tube 18 when the movable core 63 slides.
This is similar to the example.

When the valve member 62 closes the valve, the movable iron core 63
When the valve starts sliding, pressure fluid also flows out from between the end face of the movable iron core 63 and the valve body 51, but since the flow path from the fluid introduction hole 64 to the gap between them is narrowed by the guide cylinder 59. , the pressure fluid flowing through this narrow channel is restricted and the above-mentioned concentric return action is not disturbed.

When the excitation of the excitation coil 11 is cut off, the movable iron core 63 opens the valve seat 54a by the return spring 28.
The sliding speed of the movable iron core 63 due to the return spring 28 is
Since the pressure fluid from the jet hole 58 provided in the valve body 51 decelerates in the same manner as in the first embodiment, the impact caused by the collision between the movable iron core 63 and the valve body 51 is alleviated.

[Effects of the Invention] The present invention provides for either the outer circumferential wall of the movable iron core that opens and closes the valve seat or the outer circumferential fixed portion surrounding it.
By opening multiple rows of radial outflow holes in the circumferential direction that allow some of the pressure fluid flowing through the solenoid valve to flow out toward the opposing surface, the radial pressure that flows out from these outflow holes toward the opposing surface is reduced. The movable core is supported by the air bearing effect caused by the fluid and is prevented from coming into contact with the fixed part of its outer periphery, so there is almost no wear on the movable core, making it possible to use it at extremely high frequencies. This has the effect of dramatically increasing the life of the valve.

Furthermore, the pressure fluid that flows along the outer circumferential wall of the movable core to support the movable core utilizes the pressure fluid that flows through the electromagnetic valve and does not require any other pressure source or piping, so the structure is simple.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view showing a first embodiment of the present invention, FIG. 2 is a sectional view taken along line A-A in FIG. 5 is a longitudinal sectional front view showing the second embodiment of the present invention, FIG. 5 is a sectional view of a main part illustrating its function, FIG. 6 is a sectional view taken along line B-B of the movable iron core in FIG. The figure is a longitudinal sectional front view showing a third embodiment of the present invention, and FIG. 8 is a plan view of the movable iron core of FIG. 7. 2, 32, 52... Inflow port, 3, 33, 5
3... Outflow port, 4a, 34a, 54a... Valve seat, 5, 6, 35, 36, 55, 56... Passage,
10... Electromagnetic operation section, 22a, 43a, 63a...
...Outflow hole, 25... Gap, 27, 43, 63...
Movable iron core.

Claims (1)

[Scope of Claims] 1. A solenoid valve comprising an inflow port and an outflow port for pressurized fluid, a passageway that communicates both ports, a valve seat formed in the passageway, and an electromagnetic operation unit that opens and closes the valve seat. A part of the pressure fluid flowing through the solenoid valve is directed to either one of the outer peripheral wall of the movable core in the electromagnetic part and the outer peripheral fixed part surrounding it, and flows out toward the other, thereby making the movable iron core non-contact with the outer peripheral fixed part. A solenoid valve characterized by having multiple rows of radial outflow holes in the circumferential direction for holding.