JPH032069Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an oil-immersed solenoid valve that prevents malfunctions caused by the intrusion of dust and foreign matter into hydraulic oil.

(Prior Art) For example, a solenoid valve installed in a hydraulic control circuit of an automobile transmission is installed in an oil tank containing hydraulic oil, and is used while being immersed in the hydraulic oil. In this type of use, dirt and foreign matter mixed into the oil in the hydraulic oil circulation path are carried into the oil tank together with the hydraulic oil, gradually contaminating the hydraulic oil in the oil tank. It is necessary to protect solenoid valves from contamination.

Conventionally, there is a technique disclosed in Japanese Utility Model Application Publication No. 60-52510, for example, which can be used as described above. That is, this publication discloses a pressure control device in which a plunger is directly slidably accommodated inside a cap that accommodates hydraulic oil.

(Problem that the invention aims to solve) However, in such conventional devices, dust and foreign matter mixed in the hydraulic oil flowing into the cap tend to accumulate on the sliding part of the plunger, causing malfunction. There's a problem.

The purpose of the present invention is to solve such conventional problems and provide an oil-immersed solenoid valve that protects the solenoid valve from contamination of hydraulic oil and ensures good operating condition of the solenoid valve. do.

(Means for solving the problem) Therefore, the oil-immersed solenoid valve of the present invention is provided with a plunger chamber that slidably accommodates the plunger inside the cap, and an oil passage is provided in the axial direction of the plunger chamber. In the formed oil-immersed solenoid valve, a small hole is provided in the cap that closes one end of the oil passage communicating with the plunger chamber and blocks the plunger chamber from the outside, and the small hole communicates with the plunger chamber and the outside. and providing an external oil reservoir communicating with the small hole,
The quality of the hydraulic oil that enters and exits the plunger chamber via the oil reservoir is regulated in advance, and the amount of oil that enters and exits the plunger chamber is controlled to prevent dirt and foreign matter from entering the interior of the hydraulic oil. This type of solenoid valve is characterized by ensuring good operating conditions.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings. In the drawing, 1 is a valve housing (not shown) attached to the upper part of the oil tank, and the spool is inserted into the through hole 2 formed inside the valve housing. 3 is slidably housed. A stepped recess 4 communicating with the through hole 2 is opened at the end of the valve housing 1, and a valve seat 5 is accommodated in the recess 4.

The valve seat 5 is placed between the end face of the spool 3 and a stopper, which will be described later, and has a pilot pressure chamber 6 and a diaphragm chamber 7 opened at its shaft end.
A valve chamber 8 communicating with both chambers 6 and 7 is formed between them. A poppet valve 9 is accommodated in the diaphragm chamber 7 and valve chamber 8 so as to be slidable in the directions of the respective chambers 6, 7, and 8, and the bottom of the valve chamber 8 and the large diameter portion 9a of the poppet valve 9 are normally connected. A spring 10 inserted between the two is biased toward a stopper, which will be described later.

A diaphragm chamber 11 is attached to the poppet valve 9, and the peripheral end of the diaphragm 11 is held in an annular groove 12 formed at the mouth edge of the diaphragm chamber 7, and pilot pressure chambers 6 are located on both sides of the groove. The conduction of the plunger chamber, which will be described later, is cut off.

On the other hand, a bottomed cylindrical cap 13 is fixed to the end of the valve housing 1.
A small hole 14 is formed in the center of the bottomed part of the oil sump 1, which is made up of a curved pipe that rises upward around the opening.
One end of 5 is fixed. The tip of the oil reservoir 15 is opened upward, and the open end is positioned below the oil level 17 of the hydraulic oil 16 contained in the oil tank, and the inside is filled with the hydraulic oil 16. The volume of this oil reservoir 15 is configured to be larger than the volume change of the plunger chamber based on the displacement of the plunger, which will be described later, or in other words, the volume of the hydraulic oil displaced by the plunger.

An inner housing 18 and a stopper 19 are housed inside the cap 13 and spaced apart from each other.
The inner housing 18 is a hollow cylinder having a through hole 20 formed therein, and a recess 21 is formed in the end face of the flange 18a. A flange portion 22a of the housing stud 22 is accommodated in the recess 21, and a through hole 22a is provided between the end surface of the flange portion 22a and the inner bottom surface of the cap 13.
A sheet 24 formed with 3 is inserted.

On the other hand, the stopper 19 is made of a hollow cylindrical body with an oil passage 25 formed therein, and a recessed hole 26 is formed at the end of the shaft cylindrical portion 19a, and a non-magnetic bottomed pipe is inserted into the recessed hole 26. Bottomed part 2 of slide guide 27
7a is accommodated. Above slide guide 27
A majority of the outer peripheral surface of the slide guide 27 is closely accommodated in the through hole 20 of the inner housing 18, and its open end is in contact with the inner end surface of the flange portion 22a. A chamber 28 is formed.

A plunger 29 is housed in the plunger chamber 28 so as to be slidable along the inner circumferential surface of the slide guide 27, and recesses 30, 3 in both end faces thereof communicate with each other.
1 is open. A spring 32 is inserted between the concave hole 30 and the end face of the poppet valve 9, and the spring 32 causes the plunger 2 to
9 is transmitted to the poppet valve 9. That is, the spring 32 functions as a push rod with elasticity.

On the other hand, the shaft cylinder portion 22b of the housing stud 22 is inserted into the recessed hole 31, and the shaft cylinder portion 22b of the housing stud 22 is inserted into the recessed hole 31.
A communication hole 33 having the same diameter as the through hole 23 is formed in b, and a spring 34 is inserted between the inner end surface of the bottom cap 13 of the recessed hole 31 and the plunger 29 through this hole 33. It is biased in the direction of the stopper 19.

In addition, numeral 35 in the figure represents a gap as a non-magnetic portion provided between the inner housing 18 and the opposing end surface of the stopper 19, and it is also possible to construct this gap with a non-magnetic member. 36 is an excitation coil whose lead wire is connected to the connector 37, and 38 is a through hole opened in the circumferential surface of the shaft cylinder portion 22b, which is electrically connected to the plunger chamber 28 and the communication hole 33. 39 is an orifice formed between the recesses 30 and 31.

(Function) The oil-immersed solenoid valve configured as described above is installed, for example, in the upper part of an oil tank, and most of it is immersed in the hydraulic oil 16 housed in the oil tank as shown in the figure, and is attached to the cap 13. The protruding oil reservoir 15 is also immersed in the hydraulic oil 16, and the hydraulic oil 1 is contained inside it.
6 is fulfilled.

On the other hand, inside the electromagnetic valve, the oil reservoir 15 is connected to the small hole 14 and the communication hole 33, and furthermore, the recessed hole 3 that communicates with each other.
0 and 31, the plunger 29 accommodated in the plunger chamber 28 is stationary at a position where the springs 10, 32, and 34 are balanced, and its outer peripheral surface is connected to the slide guide. It is in close contact with the inner peripheral surface of 27. The poppet valve 9 is stationary at a position where the springs 10, 32, and 34 are balanced, and the peripheral end of a diaphragm 11 attached to its shaft is pressed against the end surface of the stopper 19. The communication between the pilot pressure chamber 7 and the plunger chamber 28 located on both sides is cut off.

When the excitation coil 36 is excited as the hydraulic circuit operates under such circumstances, the coil 3
6, a magnetic flux proportional to the excitation current is generated, and the rollers form a magnetic circuit between the inner housing 18, the plunger 29, and the stopper 19.
The plunger 29 is attracted toward the stopper 19,
The poppet valve 9 is moved to the left in the drawing against the spring 10 via the spring 32.

In this case, the plunger 29 is connected to the slide guide 2.
Since the slide guide 27 is made of non-magnetic material,
There is no fear that the plunger 29 will stick to the inner peripheral surface of the guide 27. Moreover, since the guide 27 is closely housed within the inner housing 18 and is arranged to have a common axis with the housing 18, the plunger 29 itself, which is inscribed in the slide guide 27, is also urged to center itself. It moves concentrically with the guide 27 and can perform smooth and stable operation.

When the plunger 29 moves in this manner, the volumes of the plunger chambers 28 on both sides thereof change. That is, the plunger chamber 28 on the moving side of the plunger 29
The volume of the plunger chamber 2 on the opposite side decreases.
8 increases, the plunger chamber 28 on the decreasing side
The hydraulic oil inside is pushed away to the oil passage 25 side, and a part of it moves from the orifice 39 to the communication hole 33 side.

On the other hand, since a negative pressure is formed in the plunger chamber 28 on the volume increasing side, the hydraulic oil in the communication hole 33 is sucked into the plunger chamber 28 through the through hole 38, and the oil corresponding to this suction amount is The amount is oil sump 15
From there, it is replenished into the communication hole 33 through the small hole 14.
In this case, the hydraulic oil supplied to the plunger chamber 28 is mostly supplied by the hydraulic oil in the communication hole 33 and the displaced part of the hydraulic oil, so the amount of replenishment from the oil reservoir 15, in other words, replacement The amount is suppressed to a small amount, and the hydraulic oil in the communication hole 33 and the plunger chamber 28 maintains substantially the original oil quality. Moreover, oil sump 15
Since it is composed of a pipe and is isolated from the surrounding hydraulic oil 16, the intrusion of dust and foreign matter is suppressed accordingly.

In addition, around the small hole 14 in the oil reservoir 15, the hydraulic oil 16 does not move in and out of the oil tank as it does around the upper opening end, so relatively clean hydraulic oil with less dust and foreign matter stays there. Since this oil is exchanged into the communication hole 33 through the small hole 14 as described above, the oil quality inside the solenoid valve will not deteriorate due to the exchanged oil from the oil reservoir 15.

Note that when the hydraulic oil pushed away by the plunger 29 moves into the oil passage 25, the pressure inside the oil passage 25 is increased and the poppet valve 9 is pressed against the spring 10.
The pilot pressure chamber moves slightly in the 6 direction against the
As mentioned above, the pilot pressure chamber 6 and the plunger chamber 2
8 is isolated by the diaphragm 11, the hydraulic fluid does not flow out toward the pilot pressure chamber 6.

Next, when the current applied to the excitation coil 36 is controlled to decrease, for example, and the magnetic flux generated in the coil 36 decreases, the plunger 29 moves the spring 3 by that amount.
2, it is pushed back and moves to the right in the figure. For this reason, the plunger chambers 28 on both sides of the plunger 29
A change in volume occurs, and the volume of the plunger chamber 28 decreases on the moving side of the plunger 29, and the volume increases on the opposite side of the plunger chamber 28.

Therefore, the hydraulic oil in the plunger chamber 28 on the volume decreasing side is pushed away by the plunger 29, and is discharged into the communication hole 33 through the through hole 38, and a part of it passes through the orifice 39 and is transferred to the volume increasing side. is sucked into the plunger chamber 28, and the other part is discharged from the through hole 23 through the small hole 14 to the oil reservoir 15.

Even in this case, most of the hydraulic oil pushed away by the plunger 29 moves to the other plunger chamber 28, and the hydraulic oil discharged from the small hole 14 is suppressed to a small amount, so that the inside of the solenoid valve is The hydraulic oil maintains approximately the original oil quality.

In this way, the hydraulic oil in the plunger chamber 28 is supplied and discharged by the displacement of the plunger 29, and a predetermined amount of hydraulic oil flows in and out from the small hole 14 each time. As mentioned above, since both of these are suppressed to a small amount, the oil quality inside the solenoid valve is kept approximately constant, and dirt and foreign matter mixed in the replacement oil supplied from the oil sump 15 are prevented from entering the solenoid valve. This means that the intrusion of these intruders is prevented, and malfunctions caused by these intrusions can be avoided.

(Effects of the invention) As described above, the oil-immersed solenoid valve of the present invention has a plunger chamber that slidably accommodates the plunger inside the cap, and an oil-immersed solenoid valve with an oil passage formed in the axial direction of the plunger chamber. In the type solenoid valve, a small hole is provided in the cap that closes one end of the oil passage communicating with the plunger chamber and blocks off the plunger chamber from the outside, and the small hole communicates with the plunger chamber and the outside. An oil reservoir is provided externally that communicates with the small hole.
The oil quality of the hydraulic oil flowing in and out of the plunger chamber is regulated in advance in the oil reservoir, and the amount of oil flowing in and out of the plunger chamber is controlled, and in particular, the amount of oil supplied from the oil reservoir to the plunger chamber as replacement oil is suppressed as much as possible. Therefore, it is possible to prevent dust and foreign matter mixed in the replacement oil from entering the solenoid valve, eliminate concerns about malfunction caused by these, and ensure a good operating condition.

[Brief explanation of the drawing]

The figure is a sectional view showing an embodiment of the present invention. 13...Cap, 14...Small hole, 15...Oil reservoir, 25...Oil passage, 28...Plunger chamber, 29
...Pranjiya.

Claims (1)

[Scope of utility model registration request] In an oil-immersed solenoid valve that includes a plunger chamber that slidably accommodates a plunger inside a cap and an oil passage formed in the axial direction of the plunger chamber, one end of the oil passage communicating with the plunger chamber is closed, and the above-mentioned An oil immersion device characterized in that a small hole is provided in the cap that blocks off the plunger chamber from the outside, the small hole communicates with the plunger chamber and the outside, and an oil reservoir communicating with the small hole is provided outside. type solenoid valve.