JPS6196277A - Electromagnetic selector valve - Google Patents

Abstract

PURPOSE:To secure the certain valve operation by allowing only the first valve piece to be attracted when a solenoid is put into weak conduction and allowing the first and the second valve pieces to be attracted when the solenoid is put into strong conduction. CONSTITUTION:In an electromagnetic selector valve, the valve bodies 4 and 5 operated by the electromagnetic attraction force for opening and closing the first and the second ports 1 and 2 can be slided independently in a magnetic cylinder body 10. The throttle part 10a for the magnetic flux is formed onto the magnetic cylinder body so that the magnetized state of each valve body differs in case of the weak conduction state and the strong conduction state for a solenoid. In case of the weak conduction, the magnetic attraction force is exerted only onto a valve body 4 for the first port, and in case of the strong conduction, the magnetic attractin force can be exerted onto the valve bodies 4 and 5 for the respective ports.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a three-port electromagnetic device that is equipped with an inlet and an outlet for pressurized fluid, as well as a relief port, and is suitable for incorporation into a braking device of an automobile. Regarding valves.

[Prior art] A conventional 3-port solenoid valve is, for example,
9, a cylindrical valve housing surrounded by an electromagnetic solenoid has one cylindrical end provided with a fluid inlet port 1, and the other cylindrical end provided with an outlet port and a relief port. A single cylindrical slider with valve bodies at both ends, each biased toward the valve closing side by spring force, resists the spring action force of the slider positioning spring depending on the strength of the current flowing through the solenoid. Generally, the open/close state of each port can be changed by moving the valve inside the valve housing. One of the major difficulties with this type of solenoid valve is that it is difficult to balance the acting force between at least two groups of springs, each with a different spring action force, built into the valve housing, with the electromagnetic attractive force exerted on the slider. Under these circumstances, it is extremely difficult to select an appropriate valve so that the valve opening and closing operations can be performed as desired. There are variations in spring action force and electromagnetic action force due to hysteresis,
The surrounding resistance of the members due to the structure of the valve body and the pressure fluctuations of the fluid itself flowing into the valve are also causes of unstable movement of the slider.

[Problems to be Solved by the Invention] The present invention provides a three-port electromagnetic switching valve that incorporates a plurality of springs for actuating the valve body, as described in the prior art section. It is an object of the present invention to provide a valve structure that can perform preferable matching of electromagnetic attraction force and electromagnetic attractive force as easily as possible, and that ensures reliable valve body operation.

[Means for Solving the Problems] In order to achieve the above object, the electromagnetic switching valve of the present invention has first and second ports having valve seats, and a third port having no valve seats.
A three-port solenoid valve comprising an electromagnetic solenoid, a magnetic cylinder as a side wall of a valve housing disposed inside the solenoid, and a first magnetic cylinder disposed at both ends of the housing, respectively. a first valve for opening and closing the first port, which is housed in series so as to be able to slide independently in the magnetic cylinder to the port and the second bow 1;
a second valve body for opening and closing the second port; a magnetic flux constriction portion provided near the first valve body of the magnetic cylindrical body; and the first valve body and the second valve body. a first spring that is interposed between the valve elements and biases both valve bodies in the valve closing direction; and a second spring that biases the first valve body in the valve opening direction against the first spring. When the solenoid is weakly energized, the first valve body is attracted and the first port is closed, and when the solenoid is strongly energized, the second valve body is also attracted and the second port is opened. The configuration was adopted.

[Operations and Effects of the Invention] As already described in the previous section, the electromagnetic switching valve of the present invention has the first
The valve bodies operated by the electromagnetic attraction force to open and close the second bow I can each independently slide inside the magnetic cylinder, and when the solenoid is weakly energized and when it is strongly energized, Since the magnetic cylinder is provided with a magnetic flux restrictor so that the magnetization state of each valve body can be made different,
When weakly energized to close the first port, a magnetic attraction force can be applied only to the first port valve body, which in turn opens the second port and maintains the first port closed. When strongly energized, a magnetic attraction force can be exerted on each valve body for each port.

In addition to setting the conditions for selectively applying magnetic attraction force to the two valve bodies, in addition to the energization level to the solenoid, the magnitude of the magnetic flux throttling effect and the adjacent This can also be done arbitrarily by adjusting the gap between the entraining sliders of the respective valve bodies.

Therefore, compared to conventional electromagnetic switching valves, it is possible to set the balance between the electromagnetic attraction force as the motive force for opening and closing the valve body and the spring acting force of multiple springs without much care. The valve body can now be operated independently and reliably, eliminating the risk of accidents caused by malfunctions of hydraulically operated equipment due to failure or malfunction of the solenoid switching valve, and making valve design easier. You will be able to do this.

[Embodiments] The electromagnetic joint valve of the present invention will be explained based on the embodiments shown in the drawings.

FIG. 1 is a side sectional view of the electromagnetic switching valve of the present invention in a non-energized state, and the valve housing, which has a short cylindrical shape as a whole, has a
It is composed of a cylinder wall member formed by joining a magnetic cylinder 10 and a non-magnetic cylinder 11, a cylinder top part 12 and a cylinder bottom member 13, and is fitted into the inner cavity of a cylindrical electromagnetic solenoid 14. is in a state of Reference numeral 15 indicates an outer tube serving as a casing for housing the solenoid 14, 16 indicates an upper cover of the casing, and 17 indicates a bottom cover portion of the casing, which is a cylinder bottom member 13.
It is integrated with.

A first port 1 is formed at one end of the valve housing, in this case the bottom of the cylinder, and a second port 2 is formed at the top of the cylinder at the other end.
and a third port 3 are provided.

Inside the magnetic cylindrical body 10, a valve body 4 for opening and closing the first port 1 and a valve body 5 for opening and closing the second port 2 are arranged on the inner periphery of the sliders 6 and 7, each having a short cylindrical shape. incorporated into the
They are housed so that they can slide in series in the sleeve direction. Valve body 4
A ball valve is fixed to each of the valve seats 18 and 5, and faces each valve seat 18 and 19.

The magnetic cylindrical body 10 made of a magnetic material such as iron has an outer diameter narrowed at a portion of the first valve body 4 housed in the cylindrical body 10 that faces the slider 6, so that the lines of magnetic force passing through the slider 6 are narrowed. A constricted portion 10a is formed.

8 is a first spring that presses the sliders 6 and 7 for driving the first and second valve bodies 4 and 5 in directions away from each other; 9 is a first spring that presses the sliders 6 and 7 against the pressing force of the first spring 8;
a is the second spring that presses both sliders 6
．． This is the gap between 7 and 7. 20 is a dust removal filter provided at the outlet of each port, 21 is a packing material, and 22 is a sliding ring. Of the above members, 10.13.15
．． 16 and 17 are made of magnetic material, and 4, 5.11 and 12 are made of non-magnetic material.

Furthermore, Fig. 1 shows the main parts of the hydraulic circuit when the electromagnetic switching valve of the present invention is incorporated into an undesired hydraulic system of an automobile, where A is the brake pedal, B is the mask cylinder, C is drum brake, D is wheel cylinder, E
is an oil pump, F is a reservoir, and G is a check valve.

FIG. 2 shows a state in which a weak current is passed through the electromagnetic switching valve shown in FIG. 1, and the first port 1 and the second port 1 to 2 are both closed.

FIG. 3 shows the state in which a strong current is passed through the electromagnetic switching valve shown in FIG. 1, with the first port 1 remaining closed and the second port 2 being open.

Next, the operation of the electromagnetic switching valve of the present invention will be explained with reference to FIGS. 1 to 3.
When the first valve body 4 is not energized, the first valve body 4 has its entraining slider 6 pressed upward by the second spring 9, so that the valve seat 18 of the first port 1 is open. Further, since the entraining slider 7 of the second valve body 5 is pressed upward by the first spring 8, the valve seat 19 of the second port 2
is closed.

When a weak current is passed through the electromagnetic solenoid 14, the relatively weak lines of magnetic force generated are caused by the upper cover 1 of the solenoid casing.
6. An attempt is made to follow the magnetic path formed by the connection of the magnetic cylinder 10, the adjacent sliders 7 and 6 arranged in series, and the casing bottom cover 17 to return to the solenoid 14, but the slider 7 There is a gap a between and 6
Because of the existence of the gap a, the gap a exhibits a large magnetic resistance, so that almost no lines of magnetic force flow through the slider 7, so the slider 7 is not magnetized and is therefore not subjected to the attraction force of the solenoid 14. On the other hand, since magnetic lines of force can pass through the slider 6 as shown by the dashed line in FIG. 2, the slider 6 is magnetized and the solenoid 14
is pushed down against the pressing force of the second spring 9 by the suction force of
8, a so-called neutral state of valve operation is brought about.

Next, when a strong current is applied to the solenoid 14, when the strong magnetic field lines generated from the solenoid 14 pass through the magnetic cylinder 10, they are formed by reducing the thickness of the cylinder wall.
If a certain amount of the magnetic field lines pass through this area, the magnetic field lines will reach a state of magnetic saturation, so the magnetic j lines will be unable to advance any further, and the third Slider 7 as shown in the dashed line in the figure.
The slider 6 is forced to pass through the gap a having a large magnetic resistance, and the slider 6 is forced to follow the magnetic path back to the casing bottom plate 17. In this case, unlike when the current is weakly energized, the lines of magnetic force possessing sufficiently large magnetic energy can penetrate the air gap a.
The slider 7 is strongly magnetized and is pushed down together with the slider 6 by the attractive force of the solenoid 14 against the pressing force of the first and second springs 8.9, and the first port 1 is closed. The valve seat 19 of the second port 2 is unblocked by the second valve body 5. The degree to which such valve operation is performed when the energization level to the solenoid 14 is increased depends largely on the distance of the air gap a and the spring acting forces of the first and second sprues and J legs 8 and 9. Although the distance of the gap a can be easily adjusted, the distance between the first spring and the first spring, which is shared by both the first and second valve bodies to keep them closed, is controlled by the distance between the first and second valve bodies.
Determining the desired spring acting force of each of the valve elements and the second spring for keeping the valve open can be relatively easily determined because the mechanism of operation thereof is simple.

In the above embodiment, the magnetic flux constriction portion 10a provided in the magnetic cylinder 10 is formed by a method of uniformly reducing the wall thickness of the cylinder wall at the portion where the cylinder 10 faces the first valve body 4. ,
In addition, the thickness of the cylindrical wall is gradually changed by forming a tapered shape, or an annular groove is provided on the cylindrical wall, etc., so that the lines of magnetic force can pass through the sliders 6 and 7 in accordance with the level of energization to the solenoid 14. The shape of the constricted portion 10a for arbitrarily distributing the holes can be devised in various ways as necessary. ! Next, when the solenoid 14 is in a de-energized state during normal driving, the solenoid 14 is in a de-energized state. When a person depresses the brake pedal 8 with a normal degree of depression, brake fluid pressure corresponding to this amount of depression is generated in the mask cylinder B, and the brake fluid pressure corresponding to the amount of depression is generated in the mask cylinder B, which is the hydraulic pressure inlet of the electromagnetic switching valve. The pressure is transmitted from the first port 1 to the third port 3, which is a hydraulic pressure outlet, to the wheel control wheel cylinder D, and an appropriate degree of braking is performed. If the driver senses the occurrence of danger and slams on the brakes, causing the wheels to approach a slipping state, an electronic device installed to predict the occurrence of slipping will activate and weakly energize the solenoid 14. When this happens, the hydraulic pressure inlet port (first port) 1 is closed, and henceforth the wheel cylinder D is maintained at a constant hydraulic pressure level. Furthermore, when the wheel approaches a slip state, a strong current is caused to flow through the solenoid 14, so the inlet port (
The first port) 1 is closed, and the second port 2, which serves as a hydraulic pressure relief port, is opened, and the brake fluid in the wheel cylinder D flows from the third port 3 to the second port 2 to the reservoir F. At the same time, oil pump E starts to assist in this discharge. Therefore, the wheels can be prevented from being locked due to a constant increase in the internal pressure of the wheel cylinder D due to excessive depression of the brake pedal A. Although a drum brake C is shown as a wheel brake in FIG. 1, it goes without saying that a disc brake would have the same effect.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of the electromagnetic switching valve of the present invention in a non-energized state, and schematically shows how it is incorporated into a hydraulic circuit of an anti-skid hydraulic device of an automobile. FIGS. 2 and 3 are side sectional views under weak energization and strong energization, respectively. In the diagram 1... 1st port 2... 2nd port 3.
...Third port 4...First valve body 5...Second valve body 6.7...Slider 8...First spring
9... Second spring 10... Magnetic cylinder 10a
...Magnetic flux constriction section 14...Solenoid

Claims (1)

[Claims] 1) A three-port solenoid valve comprising first and second ports having a valve seat and a third port not having a valve seat, comprising: an electromagnetic solenoid; and a solenoid disposed inside the solenoid. a magnetic cylinder serving as a side wall of the valve housing; a first port and a second port respectively provided at both ends of the housing; a first valve body for opening and closing the first port and a second valve body for opening and closing the second port, which are housed; and a magnetic flux constriction portion provided near the first valve body of the magnetic cylinder. a first spring that is interposed between the first valve body and the second valve body and urges both the valve bodies in the valve-closing direction; and a first spring that urges the first valve body to open against the first spring. When the solenoid is weakly energized, the first valve body is attracted and the first port is closed. When the solenoid is strongly energized, the first port is closed. An electromagnetic switching valve characterized in that the second valve body is also attracted and the second port is opened.