JPH0633267Y2 - Solenoid hydraulic valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an electromagnetic hydraulic valve that is less prone to malfunction due to contaminants mixed in oil. The device of the present invention can be used, for example, in a pressure control valve of a hydraulic system.

[Prior Art] A conventional electromagnetic hydraulic valve is shown in FIG. This electromagnetic hydraulic valve
A solenoid portion 100 having a shaft chamber 101 having one end opening and a shaft 102 slidably held in the shaft chamber 101, a spool chamber 202 having an opening 201 communicating with an opening 103 of the shaft chamber 101, and a spool chamber 20.
2 and a hydraulic control valve unit 200 having a spool 203 slidably held by the shaft 2 and biased by the shaft 102.

The solenoid unit 100 includes a case 104 made of a magnetic material,
The coil 105 inserted and fixed in the case 104, the extremely magnetic ring 106, and the case 104 together with the coil 10
5, the magnetic bodies 107, 108 arranged so as to surround
109, magnetic materials 108, 109 and non-magnetic material ring 106
And a shaft 102 that is inserted into a shaft chamber 101 formed inside. The hydraulic control valve unit 200 includes a housing 207 having an inlet hole 204, an outlet hole 205, a drain hole 206, and a spool chamber 202 inserted therethrough, a spool 203 inserted into the spool chamber 202, and an opposite side of the shaft 102. It is mainly composed of a coil spring 208 that presses the spool 203.

In this electromagnetic hydraulic valve, when a voltage is applied to the coil 105, the shaft 102 linearly moves due to the electromagnetic force of the coil and urges the spool 203 to control the oil flow of the hydraulic control valve unit 200.

[Problems to be Solved by the Invention] However, the conventional electromagnetic hydraulic valve described above has the following problems.

That is, in the opening 201 of the spool chamber 202 that communicates with the opening 103 of the shaft chamber 101, the movement of the spool 203 via the shaft 102 by the coil 105 naturally requires the oil to flow in and out of the outside via the drain hole 206. To do. As a result, the contaminants mixed in the oil may be mixed in the shaft chamber 101 and interfere with the operation of the plunger 300. Particularly when the contaminant is a magnetic substance such as iron powder, the magnetic force of the solenoid 100 accumulates in the shaft chamber 101 to interfere with the operation of the plunger 300, or the magnetic circuit characteristics of the solenoid are changed. In some cases, the plunger 300 could not exert the desired biasing force.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an electromagnetic hydraulic valve that is less likely to malfunction due to contaminants mixed in oil.

[Means for Solving the Problems] The electromagnetic hydraulic valve of the present invention has a shaft chamber 11 having an opening 13 at one end and one end inserted through the opening 13 so as to be slidable in the shaft chamber. A solenoid portion 10 having a shaft 12 to be held, a solenoid for exerting a magnetic force on the shaft, a spool chamber 22 having an opening portion 21 abutting so as to communicate with the opening portion 13, and the spool chamber 22 of the spool chamber 22. Opening 2
Hydraulic control valve section 20 having one end 231 movably inserted in 1 and having a spool 23 slidably held in the spool chamber 22 in the same direction as the shaft 12 and biased by the shaft 12. In the electromagnetic hydraulic valve, the hydraulic control valve portion 20 includes the opening portion 21 of the spool chamber 22 between the shaft 12 and the spool 23.
Has a drain hole 26a for communicating with the outside, and the hydraulic control valve portion 20 has a cylindrical shape formed of a non-magnetic material in the opening portion 21 of the spool chamber 22 communicating with the opening portion 13 of the shaft chamber 11. Of the guide ring 30. The guide ring 30 has an inner periphery formed with an insertion hole through which the one end 231 of the spool 23 and the one end of the shaft 12 are movably inserted, and the drain hole 26a. The small diameter portion 30b is axially projected from one end of the guide ring 30 on the spool chamber 22 side while facing the opening with a predetermined gap.

[Operation] In the electromagnetic hydraulic valve of the present invention, when a current is applied to the coil, the spool operates via the shaft. Oil moves in and out due to the movement of the spool through a small diameter portion and a drain hole at one end of the guide ring, and the small diameter portion is formed corresponding to the drain hole, so that the oil flows into the spool chamber from the spool side. As it exits, the guide ring acts to block the inflow of contaminants from the outside into the shaft chamber.

[Embodiment] A sectional view of an electromagnetic hydraulic valve of the present invention is shown in FIG.

This electromagnetic hydraulic valve is a spool having a solenoid portion 10 having a shaft chamber 11 open at one end and a shaft 12 slidably held in the shaft chamber 11, and an opening portion 21 communicating with an opening portion 13 of the shaft chamber 11. Chamber 22 and spool chamber 2
2, a hydraulic control valve portion 20 having a spool 23 slidably held by the shaft 2 and biased by the shaft 12 and a non-magnetic guide ring 30 fixed to the opening 21.

The solenoid unit 10 includes a case 14 which is a cylindrical container having a bottom at one end, a coil 15 which is inserted and fixed in the case 14,
Magnetic bodies 17, 18, 19 arranged inside the case 14
And a shaft chamber 11 formed inside the magnetic bodies 17, 18 and 19, and a shaft 12 inserted into the shaft chamber 11. The coil 15 has a cylindrical shape and is wound around the bobbin 41 and fixed in the case 14. The magnetic body 17 is a cylindrical member having a flange portion that is inserted and fixed in the case 14 on the side of the opening portion 13 of the solenoid portion 10 and forms a part (yoke) of the magnetic circuit. The magnetic body 18 is a cylindrical member that is inserted and fixed to the inner peripheral surface of the through hole of the magnetic body 17 and constitutes a part (yoke) of the magnetic circuit. The magnetic body 19 is a cylindrical member that is inserted and fixed inside the bobbin 41 on the side opposite to the opening 13 of the solenoid portion 10 and forms a part of the magnetic circuit. Further, one end of the magnetic body 19 is fitted into a hole at the bottom of the case 14, and the one end of the magnetic body 19 is connected to the shaft 12
Is screwed with a screw 52 for adjusting the working distance of the. The non-magnetic body ring 16 is inserted and fixed inside the bobbin 41 via a spacer 42, and abuts on the magnetic body 17 at one end,
It is a cylindrical member that is in contact with the magnetic body 19 at the other end. And the non-magnetic ring 16 and the magnetic bodies 17, 1
The internal through holes 9 are integrally communicated with each other to form a shaft chamber 11, and a shaft 12 to be described later is slidably held by the inner surface of the internal through hole. Shaft 1
Reference numeral 2 denotes a cylindrical magnetic body (plunger) 4 slidably held in the internal through hole forming the side surface of the shaft chamber 11.
3 and a non-magnetic front shaft portion 44 and a rear shaft portion 45 that are inserted and fixed inside the magnetic body 43.

The front shaft portion 44 is arranged in the shaft chamber front portion 46 on the opening 13 side, and one end thereof is inserted into the internal through hole of the magnetic body 18. The rear shaft portion 45 is arranged in the rear portion 47 of the shaft chamber opposite to the opening 13. Further, the front shaft portion 44 and the rear shaft portion 45 are formed with communication holes 48 and 49 that communicate the shaft chamber front portion 46 and the shaft chamber rear portion 47 through the internal through holes of the magnetic body 43.

Further, a resin portion 51 for fixing the terminal 50 is fixed in a hole formed in the bottom of the case 14. The terminal 50 is a terminal of the coil 15.

The hydraulic control valve unit 20 is a spring offset type linear spool valve driven by the solenoid unit 10. The hydraulic control valve unit 20 includes a cylindrical housing 27 having a spool chamber 22 therein, and a spool 2 inserted in the spool chamber 22.
3, a cylindrical guide ring 30 inserted and fixed in the opening 21 of the spool chamber 22, a screw 28 screwed into the opening of the spool chamber 22 on the side opposite to the solenoid portion 10, and inserted into the spool chamber 22. And a coil spring 29 having both ends locked to one end of the spool 23. The housing 27 includes an inlet hole 24, an outlet hole 25, and a drain hole 26, which are formed at right angles to the operating direction of the spool 23.
It is a metal member having a drain hole 26a. The drain hole 26a is opened in the radial direction slightly behind the opening 21 of the spool chamber 22, and communicates the opening 21 with the outside. Further, the housing 27 has a flange portion 270 formed at one end thereof, and the case 14 has the flange portion 270 crimped so that the flange portion 270 and the magnetic body 17 contact each other. The spool 23 has a sliding portion 230 slidably held on the wall surface of the internal through hole of the housing 27, and an end portion (spool end) 231 thereof. The end portion 231 of the spool 23 is inserted through the insertion hole 30a of the guide ring 30 and is in contact with the front shaft portion 44 of the shaft 12.
Further, the end portion 231 of the spool 23 has the same diameter as the front shaft portion 44 of the shaft 12. The coil spring 29 is a biasing member that biases the spool 23 toward the solenoid section 10.

The guide ring 30 is a cylindrical member made of a non-magnetic material, and is fitted and fixed to the opening 21 of the housing 27. Further, the drain hole 26a is formed on the outer periphery of the guide ring 30.
And a small diameter portion 30b corresponding to the small diameter portion 30b is formed.
A passage 272 that connects the opening 21 of the spool chamber 22 and the drain hole 26a is formed between the drain hole 26a and the inner peripheral surface of the housing 27.

Next, the operation of this electromagnetic hydraulic valve will be described.

When a current is applied to the coil 15, a magnetic material (yoke) 17,
A fixed magnetic circuit composed of 18, 19 and the case 14 attracts the magnetic body (plunger) 43 of the shaft 12 toward the spool chamber 22. The front shaft portion 44 of the shaft 12 biases the spool 23 in the same direction, so that the spool 23
With the sliding portion 230, the inlet hole 24 and the outlet hole 25 of the hydraulic control valve portion 20 communicate with each other, and the communication between the outlet hole 25 and the drain hole 26 is blocked. Then, by cutting off the current to the coil 15, the electromagnetic biasing force on the shaft 12 disappears, the compressed coil spring 29 presses the spool 23, and the sliding portion 230 of the spool 23 causes the sliding portion 230 of the spool 23 to again enter the inlet hole 24 and the outlet hole 2.
5, the outlet hole 25 and the drain hole 26 are communicated with each other. In this way, the electromagnetic hydraulic valve controls the flow of hydraulic oil (not shown) from the inlet hole 24 to the outlet hole 25. The reciprocating motion of the shaft 12 generates a flow of hydraulic oil (in the opposite direction to the operating direction of the shaft 12) between the shaft chamber front portion 46 and the shaft chamber rear portion 47 via the communication holes 48 and 49. Further, the reciprocating movement of the spool 23 causes oil to flow in and out between the opening 21 of the spool chamber 22 and the outside (tank) via the drain hole 26a. At this time, the guide ring 30
Since a small-diameter portion corresponding to the drain hole 26a is formed in FIG. 1, a part (not shown) of non-magnetic mixture in the hydraulic oil other than the magnetic powder (not shown) is also shown in FIGS. There is also an advantage that the flow is deflected in the X direction shown in the figure and is unlikely to enter the shaft chamber 11.

Further, since the end portion 231 of the spool 23 and the front shaft portion 44 of the shaft 12 have the same diameter, the insertion hole 30a of the guide ring 30, the end portion 231, and the front shaft portion 44 are formed.
The volume between them does not change due to the reciprocating movement of the end portion 231 and the front shaft portion 44. As a result, the insertion hole 3 of the guide ring 30
The amount of oil flowing between 0a and the end portion 231 is small, and it is possible to prevent the inclusion of a contaminant (not shown) into the shaft chamber 11. As another modification, a magnet may be provided on the small diameter portion 30b of the guide ring 30.

[Effects of the Invention] As described above, the electromagnetic hydraulic valve of the present invention has the drain hole that communicates the opening of the spool chamber to the outside, and the non-magnetic cylindrical guide ring is inserted into the opening of the spool chamber. ,
Since the small diameter portion is axially projected from one end of the guide ring on the spool chamber side while facing the opening of the drain hole with a predetermined gap, the following effects can be obtained.

The guide ring installed at one end of the spool chamber has the advantage of preventing contaminants in the oil from the drain hole from flowing into the shaft chamber of the solenoid section. The problems of deterioration of sliding performance of the shaft and reduction of magnetic biasing force of the solenoid portion due to short circuit of magnetic powder in the circuit can be solved.

To explain further, oil enters and leaves the opening of the spool chamber due to axial movement of the spool through the drain hole, but the small diameter portion of the guide ring faces the opening of the drain hole with a predetermined gap. While extending in the axial direction, the axial flow of oil formed in the vicinity of the opening of the drain hole due to the axial movement of the spool flows while being guided along the outer peripheral surface of the small diameter portion, and then smoothly drains. The powder is deflected and flows into the hole, so that the powder mixed with the oil is less likely to flow into the opening of the shaft chamber.

Further, in the above configuration, the guide ring is made of a non-magnetic material even though the small diameter portion of the guide ring that guides the oil flow at the opening of the spool chamber is deeply projected into the spool chamber side. The magnetic field strength in the chamber does not increase, and the accumulation of iron powder or the like on the sliding portion in the spool chamber does not increase.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the electromagnetic hydraulic valve of the present invention. FIG. 2 is an enlarged cross-sectional view of the essential parts of the electromagnetic hydraulic valve of FIG. FIG. 3 is a sectional view of a conventional electromagnetic hydraulic valve. 10 ... Solenoid part 20 ... Hydraulic control valve part 30 ... Guide ring

Claims (2)

[Scope of utility model registration request] 1. A shaft chamber having an opening at one end, a shaft having one end inserted through the opening and slidably held in the shaft chamber, and a solenoid for exerting a magnetic force on the shaft. A solenoid chamber having an opening, a spool chamber having an opening in contact with the opening so as to communicate with the opening, and an end movably inserted into the opening of the spool chamber in the same direction as the shaft in the spool chamber. A hydraulic control valve section having a spool slidably held by the shaft and biased by the shaft, wherein the hydraulic control valve section includes the spool between the shaft and the spool. There is a drain hole that communicates the opening of the chamber to the outside, and the hydraulic control valve portion is not connected to the opening of the spool chamber that communicates with the opening of the shaft chamber. A cylindrical guide ring formed of a flexible body, and an insertion hole, through which the one end of the spool and the one end of the shaft are movably inserted, is formed on an inner circumference of the guide ring, An electromagnetic hydraulic valve characterized in that a small diameter portion is provided in an axially protruding manner from one end of the guide ring on the spool chamber side while facing the opening of the drain hole with a predetermined gap. 2. The electromagnetic hydraulic valve according to claim 1, wherein the one end of the spool has the same diameter as the one end of the shaft in contact with the spool, which is difficult to practically use.