JPS5922375Y2 - Oil immersion type solenoid switching valve - Google Patents

Description

[Detailed description of the invention] This invention operates a valve by reciprocating a movable iron core relative to a fixed iron core in oil filled in its storage chamber by biasing a spring or excitation of an electromagnetic coil. This invention relates to direct current or alternating current oil-immersed electromagnetic switching valves.

Normally, in this type of oil-immersed electromagnetic switching valve, the collision of the movable iron core against the fixed iron core that occurs during the valve switching operation takes place in a storage chamber filled with oil, so the switching noise is small and the durability is good. However, in order to prevent beats and minute vibrations from occurring when the movable iron core and fixed iron core are attracted to each other, the contact surfaces of the fixed iron core and movable iron core are made to be in close contact when they come into contact with each other. It has a precise surface finish.

However, when the movable iron core is separated from the fixed iron core when switching the valve, the contact surfaces of the movable iron core and the fixed iron core are in close contact with each other, so it is difficult for oil to enter between the circumferential contact surfaces. The movable core is pressed against the fixed core by hydraulic pressure, and it takes time to separate the movable core from the fixed core, and the moment the movable core is separated from the fixed core, it attempts to move at that high speed. Because the speed of oil flowing between the circumferential contact surfaces of the fixed iron core and the movable iron core is slow, negative pressure is temporarily generated between the circumferential contact surfaces, and as a result, the movable iron core The drawback was that it delayed the operation of the iron core.

In addition, this activation delay changes depending on the viscosity of the oil, which is a function of temperature.As the viscosity increases, the activation delay increases, while as the viscosity decreases, the activation delay decreases. The switching valve cannot be used when highly accurate control is required, and has the disadvantage that its field of use is limited.

This invention was developed in view of the drawbacks of the conventional oil-immersed electromagnetic switching valves mentioned above. The purpose is to provide type solenoid switching valves.

The oil-immersed electromagnetic switching valve according to the present invention is provided with an axial penetration portion that allows oil to freely flow across the front and rear surfaces of the movable iron core, and at least one of the movable iron core and the fixed iron core. A plurality of narrow grooves are formed on the abutment surface almost uniformly so as to partition the abutment surface into a large number of sections, and each of the narrow grooves is formed so as to be in constant communication with the through part, When the movable iron core moves back and forth toward and away from the fixed iron core, the oil in the narrow groove can freely flow, that is, when the contact surfaces of the fixed iron core and the movable iron core are in close contact with each other. , the oil is always in the plurality of narrow grooves and can easily enter between the contact surfaces at any time, and at the moment the movable iron core is separated from the fixed iron core, the oil is kept at high speed. With respect to the moving iron core, the fixed iron core of the movable iron core is moved so that the oil flows across the entire surface and instantaneously between the two contact surfaces through the above-mentioned through-hole and the plurality of narrow grooves. This makes it possible to quickly leave the country.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be explained in detail regarding a three-position closed center type electromagnetic switching valve shown in the drawings.

The oil-immersed AC electromagnetic switching valve shown in FIG.
It consists of a spool valve 2 that switches the connections of P, A, B, and T, and a pair of left and right drive means that are located on both sides of the valve body 1 and that reciprocate the spool valve 2 in the axial direction. It includes a coil spring 3 and an electromagnetic coil 4 that work in opposite directions.

The electromagnetic coil 4 excites a movable iron core 6 that is movable in the axial direction with respect to a removable fixed iron core 5 fixed to the valve body 1, and causes the front abutment surface 6a of the movable iron core 6 to move around the fixed iron core 5. Contact surface 5a
The spring 3 has a biasing force to separate the movable iron core 6 from the fixed iron core 5 and move it away from the fixed iron core 5 in the axial direction.

The bushing pin 7 that comes into contact with the axial center of the movable iron core 6 slidably passes through the through hole 5b of the axial center of the fixed iron core 5, and its front end is fixed or in contact with the spool valve 2, so that the spool The valve 2 reciprocates integrally with the movable iron core 6 via the bushing pin 7.

The movable iron core 6 has its front face facing the fixed iron core 5 and its rear face facing the plug 9 located at the end of the mold 8 of the electromagnetic coil 4, and moves reciprocally therebetween, while its peripheral surface A cylindrical pressure-resistant tube 1 integrally welded to a fixed iron core 5 and a plug 9
The outer periphery of the movable iron core 6 and the bushing pin 7 are coated with
A series of spaces S surrounded by the valve body 1, the fixed iron core 5, the tube 10, and the plug 9 where the spool valve 2 is present are filled with lubricating oil.

The electromagnetic coil 4 is arranged around the outer circumference of the tube 10, while
The spring 3 is suspended between the spool valve 2 and the fixed iron core 5.

As shown in FIGS. 3 and 4, the movable iron core 6 has a notch-shaped deep groove 11 that runs longitudinally in the axial direction and penetrates through the movable iron core 6.
A penetrating portion consisting of the deep groove 1 is provided, and the deep groove 1 is
1 to allow oil to freely flow to the front and rear of the movable iron core 6, while the flatness, straightness, and surface roughness of the contact surface 6a of the front surface of the movable iron core 6 against the fixed iron core 5 are strictly controlled. The surface is machined to a precise surface finish, and a plurality of narrow grooves 12 are formed in an annular manner around the shaft center on the corresponding contact surface 6a, with a constant interval between each other, and each end is formed into the above-mentioned deep groove. It is installed so that it communicates with 11.

The narrow groove 12 is designed to divide the abutting surface 6a of the movable iron core 6 into as many small areas as possible without significantly reducing the area of the abutting surface 6a, as shown in FIG. 5, for example.
A large number of openings are provided with a V-shaped cross section and the width Y of the opening is made as small as possible.

Therefore, the contact surface 6a of the movable iron core 6 is partitioned into a large number of small-area sections by the narrow grooves 12, and the oil from the deep grooves 11 freely flows into the narrow grooves 12 at all times. 12, oil can easily enter the entire surface of the contact surface 6a at any time.

As shown in FIG. 2, the fixed iron core 5 has a bushing pin 7 penetrating through the through hole 5b, which is formed to have a rectangular cross section, and oil flows through the notch 13 provided in the axial direction to the front and back of the fixed iron core 5. At the same time, the abutment surface 5a of the fixed iron core 5 against the movable iron core 6 is machined to a precise surface finish similar to the abutment surface 6a of the movable iron core 6, and the corresponding abutment surface An embedding groove is provided in a part of the contact surface 5a, and the corner coil 14 is embedded therein so as not to protrude beyond the contact surface 5a, as is conventionally known.

In the oil-immersed AC electromagnetic switching valve constructed as described above, when the electromagnetic coils 4 on both sides are demagnetized, the coil springs 3 on both sides bias the valve 2 to the neutral position as shown in FIG. The abutting surfaces 6a of the movable iron cores 6 on both sides are separated from the abutting surfaces 5a of the corresponding fixed iron cores 5 via the respective movable iron cores 6.

Next, when the electromagnetic coil 4 on the left side in FIG. 1 is excited, the movable iron core 6 on the left side is attracted to the fixed iron core 5 on the left side against the biasing force of the coil spring 3 on the right side. , both 5,
At the same time, the contact surfaces 5a, 5a of the valve 2 come into close contact with each other, and the valve 2
is moved to the right via Butushpin 7 and becomes Po)
A is communicated with pressure port P.

At this time, the oil present on the front surface of the movable iron core 10 freely passes through the pair of penetration parts 11 and flows into the rear surface.

Next, when the left electromagnetic coil 4 is demagnetized, the compressed right coil spring 3 presses the valve 2 to the left,
A movable iron core 6 is isolated from a fixed iron core 5 via a bushing pin 7.

At this time, between the circumferential abutting surfaces 6a and 5a of the movable iron core 6 and the fixed iron core 5, the abutting surface 6a of the movable iron core 6 is arranged so as to partition the circumferential abutting surface into a large number of sections. Because oil quickly flows over the entire surface of the contact surfaces through the plurality of narrow grooves 12 provided, the pressure of the oil acts evenly from the entire circumference of the movable iron core 6 and is balanced. The movable iron core 6 is not pressed against the fixed iron core 5 by hydraulic pressure.

Further, at the moment when the movable iron core 6 is separated from the fixed iron core 5, the circumferential contact surface 6a.

Even if a negative pressure is to be generated between 5a, the oil will not flow through the penetration
．． Since it quickly flows through the plurality of narrow grooves 12 and into the entire area between the contact surfaces 6a and 5a, there is no room for negative pressure to occur.

Therefore, even with the force of the spring 3, which is weaker than the adsorption force between the movable iron core 6 and the fixed iron core 5, the movable iron core 6 and thus the valve 2 can be quickly moved without causing any delay in operation. can.

Furthermore, by exciting the right electromagnetic coil 4,
When communicating with the pressure capo-1-P, the same action as described above between the left movable iron core and the fixed iron core is performed between the right movable iron core and the fixed iron core.

FIG. 6 shows the dimensions of the narrow groove 12 of the electromagnetic switching valve of the present invention shown in the above embodiment as seen in FIGS. 3 and 4, and the diameter is R = 6 mm, S = 9 mm, and T = 12 mm.
, U15 mm and ゛Depth X = 0.2 mm, Width Y =
0.5 mm, deep groove width V = 2.5 mm, width between deep grooves W = 3.5 mm, and a conventional oil-immersed AC electromagnetic switching valve without narrow grooves. Operation delay due to oil temperature (horizontal axis), i.e. return time of movable iron core 6 (
This is a comparison graph of the vertical axis).

・The oil used was JISK 2213-2 additive turbine oil.

As is clear from this graph, the return time shown by curve M of the conventional oil-immersed AC solenoid directional valve is 55 m at 10°C.
At 5.60°C, it becomes 20 m5, and the recovery time shown by curve N of the oil-immersed AC electromagnetic switching valve according to the used book example is 10 m5.
The return time is 3Q ms at 10°C and 18m5 at 60°C, and the oil-immersed AC electromagnetic switching valve according to this embodiment has a return time approximately % shorter than the conventional one at 10°C. It can be seen that the change in return time with respect to changes in oil temperature is smaller than in the conventional case.

In the above embodiment, the narrow groove 12 is connected to the movable iron core 6.
However, a narrow groove is provided in the abutment surface 5a of the fixed iron core 5, and the circumferential abutment is made such that the through portion 11 and the narrow groove communicate with each other when the circumferential abutment surfaces are brought into close contact with each other. It may be formed such that the through portion 11 and the narrow groove intersect when the contact surfaces 5 a and 5 b are in close contact with each other.

Further, in the above embodiment, a plurality of narrow grooves 12 are provided concentrically, but they may be provided in a ring shape such as a spiral centered on an axis, or in the shape of a mesh in the base, for example.

Furthermore, although the penetrating portion 11 is formed in a deep groove of the movable iron core 6,
It may also be formed into a thank you note.

Furthermore, although the above embodiments have been described with respect to an AC type electromagnetic switching valve, it goes without saying that the present invention can be similarly applied to a DC type electromagnetic switching valve.

As described in detail in the above embodiments, the oil-immersed electromagnetic switching valve according to the present invention has a plurality of narrow grooves provided on the contact surface of at least one of the movable iron core and the fixed iron core. It has a simple structure in which it is partitioned into compartments and the narrow groove is formed so as to be in constant communication with the above-mentioned through-hole, so that oil can quickly flow between the two soldering surfaces through the narrow groove. Therefore, the operation delay of the movable iron core can be reduced, and the change in the operation delay due to changes in oil viscosity can be reduced, and the return time of the movable iron core in response to the valve switching signal is shortened. This has the advantage that the field of use of oil-immersed electromagnetic switching valves can be expanded.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional front view of an oil-immersed AC electromagnetic switching valve according to an embodiment of the present invention, Fig. 2 is a sectional view of a part of the bushing pin and fixed iron core, and Fig. 3 is a partial sectional view of the movable iron core. 4 is a right side view of FIG. 3, FIG. 5 is an enlarged view of the main part showing the state in which the movable iron core and fixed iron core are in close contact, and FIG. 6 is the movable iron core in the conventional example and the present invention. It is a graph comparing the recovery time of . 1...Body, 2...Valve, 3...
・Spring, 4... Electromagnetic coil, 5...
... Fixed iron core, 6... Movable iron core, 5a, 5a.
- Contact surface, 11... curved penetration part, 12... narrow groove.

Claims (2)

[Scope of utility model registration request] (1) The movable iron core 6 that reciprocates in the axial direction in the oil by the biasing of the spring 3 or the excitation of the electromagnetic coil 4 to switch the valve 2 and the front surface of the movable iron core 6 in the axial direction are in contact with each other. The fixed iron core 5 has a contact surface 5a that is in close contact with the surface 6a so as to be able to come into contact with and separate from the surface 6a. A plurality of narrow grooves are provided on the abutment surface (5a or 5a) of at least one of the movable iron core 6 and the fixed iron core 5, approximately uniformly centered on the axis, so as to divide the abutment surface into a large number of sections. 12 is extended, and each of the narrow grooves 12 is formed so as to be in continuous communication with the through portion 11, so that the narrow grooves 12 are formed so as to be in constant communication with the through portion 11, so that the narrow grooves 12 are formed so as to be in constant communication with the through portion 11, and the narrow grooves 12 are formed so as to be in continuous communication with the through portion 11. An oil immersion type electromagnetic switching valve characterized by allowing free flow of oil within the width groove 12. (2) Utility model registration scope In the oil-immersed electromagnetic switching valve according to claim 1, the penetration portion 11 is a deep groove provided longitudinally in the axial direction on the circumferential surface of the movable iron core; Each narrow groove 12 is characterized in that it is formed in a substantially annular shape around the axis.