JP2001304451A - Proportional solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a proportional solenoid valve obtaining an output pressure in conformity to the carried current by avoiding excessive rise of the electromagnetic force when the distance between the core and a movable iron core remains short while in the high amperage condition. SOLUTION: A support groove 5b is provided at the inside surface of the support part 5a of a case 5, and a smooth pressure control with respect to the carried current is established by avoiding excessive rise of the electromagnetic force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a proportional solenoid valve.

[0002]

FIG. 8 is a sectional view showing a conventional proportional solenoid valve. In the figure, 21 is a bobbin, 22 is a bobbin 21
23, a movable core, 23a is a rod inserted into and fixed to the movable core 23, 24 is a core forming a magnetic circuit, 25 is a magnetic circuit similar to the core 24, and the above-described components are Case to store, 25a
Are support portions of the case 25 projecting toward the bobbin 21 side;
Reference numeral 6 denotes a nonmagnetic spacer interposed between the movable iron core 23 and the core 24.

[0003] Next, reference numeral 27 denotes a spool valve which is pushed by the rod 23a, 28 is inserted into the case 25, and the spool valve 27 slides in its inner diameter.
a is an input port, 28b is an output port, 28c is a drain port, 29 is a movable iron core 23 and a spool valve 2
7, a spring for biasing the spring 7 toward the case 25, an adjusting screw 30 for adjusting the amount of force of the spring 29, a feedback chamber 31 composed of a step of the spool valve 27 and the housing 28, and a feedback chamber 31 for output pressure. This is the feedback aperture that leads to.

Next, the operation will be described. When the power is not supplied, the spool valve 27 is located at a point where the force of the spring 29 and the feedback force generated by the output pressure being guided to the feedback chamber 31 through the feedback throttle 32 are balanced. Release the pressure according to the initial set force. When an electric current is applied to the coil 22, an electromagnetic force acts to attract the movable iron core 23 toward the core 24, so that the balance point changes, and the spool valve 27 changes the input port 28 a and the drain port 28.
The rate of closing c changes, and the output pressure drops. The output pressure becomes a pressure proportional to the current flowing through the coil 22.

[0005]

Since the conventional proportional solenoid valve is configured as described above, when controlling the pressure by balancing the spring force, the feedback force, and the electromagnetic force, the energizing current and the position of the movable iron core are controlled. If the relationship between the electromagnetic force and the electromagnetic force is poor, the balance between the spring force, the feedback force, and the electromagnetic force is lost. As shown in FIG. 9, there is a problem that the output pressure does not change despite the decrease in the current. Was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to provide a proportional solenoid valve capable of obtaining a smooth pressure with respect to a supplied current.

[0007]

According to a first aspect of the present invention, there is provided a proportional solenoid valve housed in a case and wound with a coil, and a core provided at the center of the bobbin to form a magnetic circuit. A movable core that is attracted in the direction of the core by energizing the coil, a rod that is integrated with the movable core, a spool valve that is pushed by the rod, and a housing that guides the spool valve. In this case, a groove is provided on the inner diameter side of the support portion of the case projecting toward the bobbin.

[0008] The proportional solenoid valve according to claim 2 of the present invention comprises:
A groove is provided on the end face of the movable iron core on the core side.

[0009] The proportional solenoid valve according to claim 3 of the present invention comprises:
A groove is provided on the end face of the core, on the side of the movable iron core.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to FIG. In the figure, 1
Is a bobbin, 2 is a coil wound around the bobbin 1, 3 is a movable core, 3a is a rod inserted and fixed in the movable core 3, 4 is a core constituting a magnetic circuit, 5 is a magnetic circuit similar to the core 4. And 5a is a support portion of the case 5 protruding toward the bobbin 1, and 5b is a support groove provided in an inner diameter portion of the support portion 5a. Reference numeral 6 denotes a nonmagnetic spacer interposed between the movable core 3 and the core 4.

Next, 7 is a spool valve which is pushed by the rod 3a, 8 is a housing which is inserted into the case 5 and the spool valve 7 slides in its inside diameter, 8a is an input port, 8b is an output port, 8c is a drain port, 9 is a spring for urging the movable iron core 3 and the spool valve 7 toward the case 5; 10 is an adjusting screw for adjusting the force of the spring 9; 11 is the spool valve 7 and the housing 8
A feedback chamber 12 constituted by the steps of the above is a feedback throttle for guiding the output pressure to the feedback chamber 11.

Next, the operation will be described. When the power is not supplied, the spool valve 7 is located at a point where the force of the spring 9 and the feedback force generated by the output pressure being guided to the spool valve feedback chamber 11 through the feedback throttle 12 are balanced, and the spool port 7 is connected to the output port 8b. A pressure corresponding to the initial setting force of the spring 9 is applied. When an electric current is applied to the coil 2, an electromagnetic force acts to attract the movable core 3 toward the core 4, so that the balance point changes, and the rate at which the spool valve 7 blocks the input port 8a and the drain port 8c changes. Goes down. The output pressure becomes a pressure proportional to the current flowing through the coil 2.

As shown by a broken line in FIG. 2, when the distance between the movable iron core 3 and the core 4 is shortened, the electromagnetic force suddenly increases. A phenomenon occurs in which the output pressure does not increase even if the pressure is lowered. Therefore, in the present embodiment, when the support groove 5b is provided, and when the distance between the movable iron core 3 and the core 4 is short at high current, magnetic saturation is caused to suppress the increase of the electromagnetic force. As shown by the solid line in FIG. 9, the output pressure smoothly rises as the current decreases.

The distance between the movable core 3 and the spacer 6 is
In the case of less than 2/5 of the total moving distance of the movable core 3,
The degree of increase (change) of the electromagnetic force with respect to the moving distance of the movable core 3
Is set to be equal to or less than the spring constant of the spring 9 when the direction in which the spring 9 is compressed is positive.

Further, in the proportional solenoid valve shown in FIG. 1, a case is shown in which a rectangular support groove 5b is provided in the support portion 5a, but a circular support groove 5b is provided at a position as shown in FIG.
c may be provided.

As described above, in the proportional solenoid valve according to the present invention, the support grooves 5b and 5c for adjusting the degree of magnetic saturation are provided in the inner diameter portion of the support portion 5a. When the distance is short, the electromagnetic force is prevented from increasing too much, and a smooth output pressure can be obtained with respect to the supplied current.

Embodiment 2 FIG. FIG. 4 is a cross-sectional view showing a proportional solenoid valve according to Embodiment 2 of the present invention. As shown in FIG. 4, the movable iron core 3 has an end face provided with a movable iron core groove 3b on the end face thereof. , Movable iron core 3 and core 4
May be reduced to restrict the flow of magnetic flux from the movable iron core 3 to the core 4. The shape of the groove is shown in FIG.
May be V-shaped, and although not shown, may be U-shaped.

As described above, according to the present embodiment, in order to restrict the flow of magnetic flux from the end face of the movable core 3 to the core 4, the movable core groove 3b is provided on the end face of the movable core 3 on the core 4 side. When the distance between the core 4 and the movable core 3 is short due to high current,
The electromagnetic force is prevented from increasing excessively, and a smooth output pressure can be obtained with respect to the supplied current.

Embodiment 3 In the second embodiment, the case where the groove is provided in the movable iron core 3 has been described, but the core groove 4a or 4b may be provided on the end face of the core 4 as shown in FIG. In order to restrict the flow of the magnetic flux from the end face of the movable core 3 to the core 4 in this manner, core grooves 4a and 4b are provided in the core 4 facing the movable core 3, and a high current is applied between the core 4 and the movable core 3. When the distance is short, the electromagnetic force is prevented from increasing too much, and a smooth output pressure can be obtained with respect to the supplied current.

Embodiment 4 Further, in the above embodiment, the case where the support groove 5b and the movable iron core grooves 3b, 3c or the core grooves 4a, 4b are provided at the same time is shown, but a structure in which only one of them is provided may be used.

As described above, according to the present invention, grooves are provided on the inner diameter of the support portion 5a and the end face of the movable core 3 or the end face of the core 4, and the distance between the core 4 and the movable core 3 is short at high current. Sometimes, by preventing the electromagnetic force from excessively increasing, a proportional solenoid valve capable of performing smooth pressure control with respect to the supplied current can be obtained.

[0022]

According to the proportional solenoid valve according to the first aspect of the present invention, a bobbin housed in a case and wound with a coil, a core provided at the center of the bobbin and constituting a magnetic circuit, It has a movable core that is attracted in the direction of the core by energizing the coil, a rod that is integrally attached to the movable core, a spool valve that is pushed by the rod, and a housing that guides the spool valve. Since the groove is provided on the inner diameter side of the support portion of the case that protrudes toward the bobbin, smooth pressure control can be performed on the supplied current.

According to the proportional solenoid valve according to the second aspect of the present invention, since the groove is provided on the end face of the movable iron core on the core side, it is possible to obtain a smooth output pressure with respect to the energizing current. it can.

According to the proportional solenoid valve of the third aspect of the present invention, since the groove is provided on the end face of the core on the side of the movable iron core, a smooth output pressure can be obtained with respect to the energizing current. it can.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a proportional solenoid valve according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a relationship between a movable iron core, a distance between spacers, and an electromagnetic force.

FIG. 3 is a sectional view showing a proportional solenoid valve according to Embodiment 1 of the present invention;

FIG. 4 is a sectional view showing a proportional solenoid valve according to a second embodiment of the present invention.

FIG. 5 is a sectional view showing a proportional solenoid valve according to a second embodiment of the present invention.

FIG. 6 is a sectional view showing a proportional solenoid valve according to Embodiment 3 of the present invention.

FIG. 7 is a sectional view showing a proportional solenoid valve according to Embodiment 3 of the present invention.

FIG. 8 is a sectional view showing a conventional proportional solenoid valve.

FIG. 9 is a diagram showing a relationship between an energizing current and an output pressure.

[Explanation of symbols]

1 bobbin, 2 coils, 3 movable iron core, 3a rod, 3b, 3c, 4a, 4b, 5b, 5c groove, 4 core, 5 case, 5a support section, 7 spool valve, 8 housing.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiromichi Tsugami 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term (reference) 3H106 DA03 DA23 DB02 DB12 DB23 DB32 DC09 DD09 EE04 EE07 GA01 GA13 GA15 GA30

Claims (3)

[Claims] 1. A bobbin housed in a case and wound with a coil, a core provided at the center of the bobbin, forming a magnetic circuit, and a movable core attracted in the direction of the core by energizing the coil. And a rod integrally mounted on the movable iron core, a spool valve pushed by the rod, and a housing for guiding the spool valve, the support for the case protruding toward the bobbin. A proportional solenoid valve characterized in that a groove is provided on the inner diameter side of the portion. 2. The proportional solenoid valve according to claim 1, wherein a groove is provided on an end face of the movable iron core, the end face being on the core side. 3. The proportional solenoid valve according to claim 1, wherein a groove is provided on an end face of the core, the end face being on the movable iron core side.