JPH0142706Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a proportional electromagnetic valve for flow rate control that controls the flow rate of fluid in proportion to applied current.

FIG. 1 is a longitudinal sectional view of a conventional proportional solenoid valve.
The solenoid 2 has its center hole fitted into a core 4, and its end portion is wound around a bobbin 1 which is in contact with a seat 12 via a core plate 5 and an O-ring 17. The cover 3 is a cylindrical cylinder that is fixed by a circumferential groove at the upper end to the outer circumferential part of the core plate 5 which is fitted and fixed to a cylindrical circumferential groove at the upper end of the core 4,
The flange portion at the lower end of the cover 3 contacts the upper surface of the flange portion at the upper end of the block 9 with its lower surface, and the bolt 3
It is fixed to block 9 by a. The stepped cylindrical sheet 12 has its large diameter part fitted into the cylindrical hole of the flange part of the cover 3, and its medium diameter part inserted into the cylindrical hole of the flange part of the block 9 via an O-ring 18 fitted into its circumferential groove. A flow control port 13 whose small diameter portion is inserted into a hole forming a fluid passage in block 9 to communicate passages 10 and 11 provided in block 9.
It is equipped with A cylindrical guide 6 made of a non-magnetic material has its outer peripheral surface fitted into the bobbin 1 and the seat 12, and a plunger 7 and a valve 8, which is press-fitted and fixed to the plunger 7 and moves together, are slid into the guide 6. The valve 8 has a large cylindrical portion at the top that slides on the inner circumferential surface of the guide 6, and a small cylindrical portion at the bottom that slides on the small inner diameter surface of the seat 12 to open and close the flow rate control port 13. A protrusion 20 is provided at the lowermost end. A compression spring 14 is inserted between the core 4 and the plunger 7 so as to abut the bottom of each spring counterbore.

plunger 7, core 4, core plate 5,
The cover 3 and the sheet 12 form a magnetic circuit A, and when the solenoid 2 is energized, an attractive force proportional to the current flowing through the solenoid 2 is generated between the core 4 and the plunger 7, which balances the repulsive force of the compression spring 14. , a displacement of the valve 8 occurs in proportion to the current flowing in the solenoid 2, and a fluid with a flow rate proportional to the applied current passes through the flow control port 13 in the direction of the arrow. When solenoid 2 is not energized, use compression spring 1.
The valve 8 is pushed down by the repulsive force of 4, and the seat 12
The flow control port 13 is closed and no fluid passes through it. In addition, since the communication hole 15 is provided, the plunger 7
The fluid is not trapped between the core 4, the plunger 7, and the guide 6 due to the movement of the fluid, and since the communication hole 16 is provided, the fluid is not trapped between the valve 8, the guide 6, and the seat 12.
The balance between the repulsive force of the compression spring 14 and the suction force of the solenoid 2 is not disturbed.

Further, the protrusion 20 provided on the valve 8
prevents the flow rate vibration of the flowing fluid when the flow rate control port 13 is completely opened.

Now, the generally required current/flow rate characteristics are proportional to the current applied to the solenoid 2 until the maximum flow rate Q is reached, as shown by the broken line in FIG. That is, it is a linear characteristic, and once the maximum flow rate Q is reached, a characteristic is required in which the flow rate remains constant even if the current increases thereafter. However, in the conventional example shown in FIG. 1, the current and flow rate were proportional in region a, as shown in FIG. 2, and the flow rate varied as shown by the solid line in regions b and c. The reason for this is that, as shown in FIGS. 3 to 5, in the partial opening of the valve port in FIG. 3, even if the opening area of the flow rate control port 13 is changed, the area a in FIG. However, when the current increases and the upper end of the flow control port 13 and the end of the valve 8 are in the same position, as shown in FIG.
(coander effect) and flows like a small arrow. Further, as shown in FIG. 5, when the valve 8 goes above the upper side of the flow control port 13, the valve 8
A vortex is generated by the flow adhering to the protrusion 20 and the valve 8, and this vortex causes turbulence in the fluid passing through the flow control port 13, and as the valve 8 moves upward, it becomes a resistance to the flow and reduces the flow rate by ΔQ. This is to reduce the

Note that since the protrusion 20 is added, even if the flow rate decreases, the flow rate vibration is eliminated.

The object of the present invention is to eliminate such drawbacks of conventional proportional solenoid valves and to provide a proportional solenoid valve that does not cause a decrease in flow rate.

In this invention, by energizing the electromagnetic solenoid, the plunger is attracted to the core to a position where it balances the repulsive force of the compression spring, and the end of the valve, which has a protrusion at the tip, moves in unison with the plunger and becomes a seat. A proportional solenoid valve that opens and closes a provided flow rate control port to allow a predetermined flow rate to flow from an inflow passage to an outflow passage, and is provided with a vertical hole that opens at the tip of the projection and a horizontal hole that communicates with the circumferential surface of the projection. .

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 6 shows a longitudinal sectional view. Components with the same reference numerals as those in FIG. 1 have the same configuration and function, and therefore their description will be omitted. fixed to the plunger 7, the plunger 7
There is a communication hole 15 at the center of the protrusion 20 ¹ of the valve 8 ¹ that moves together with the valve 8 1 , and the opening tip (lower end)
A plurality of horizontal holes 22 are provided to communicate the vertical hole 21 and the circumferential surface of the protrusion ²⁰¹ .

The part of the fluid that flows into the vertical hole 21 from the passage 11 as shown by the arrow flows out to the circumferential surface of the protrusion 20 ¹ through the horizontal hole 22, so that the fluid that directly flows into the circumferential surface of the protrusion 20 ¹ This prevents the flow from adhering to the circumferential surface of the protrusion ²⁰¹ .

FIGS. 7 to 9 show states corresponding to FIGS. 3 to 5. No adhering flow occurs in all the areas indicated by a, b, and c in FIG. 2. Since the adhering flow is suppressed, even in the state shown in FIG. 9, which corresponds to region c in FIG. There is no resistance, no decrease in flow rate occurs, and the characteristics shown by the broken line in FIG. 2 are satisfied.

The degree of this characteristic improvement is the protrusion 20 ¹ at the end of the valve 8 ¹
Hole diameters of the vertical hole 21 and horizontal hole 22 provided in the horizontal hole 2
It changes depending on the position of 2. If the positional relationship is such that the flow from the side hole 22 immediately flows out to the flow rate control port 13, the flow rate will change, so care must be taken. Generally, it is preferable that the side hole 22 is located at the tip of the protrusion ²⁰¹ and not facing the flow rate control port. In this embodiment, the vertical hole 21 is also used as the communication hole 15, but these two holes may be separate holes.

As described above, the present invention was able to obtain flow characteristics that eliminate flow reduction at maximum flow rate by attaching a vertical hole and a horizontal hole to the tip of the protrusion of the valve that moves together with the plunger in the proportional solenoid valve. .

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a conventional proportional solenoid valve, Fig. 2 is a current/flow characteristic diagram of the proportional solenoid valve, and Figs. 3 to 5 show fluid near the valve due to flow in the direction of the arrow in Fig. 1. FIG. 6 is a vertical cross-sectional view of an embodiment of the present invention, and FIGS. 7 to 9 are vertical cross-sectional views showing fluid flow in the vicinity of the valve due to flow in the direction of the arrow. 8,8 ¹ ...Valve, 20,20 ¹ ...Protrusion, 2
1...Vertical hole, 22...Horizontal hole.

Claims (1)

[Scope of utility model registration request] By energizing the solenoid, the plunger is attracted by the core to a position balanced with the repulsive force of the spring, and moves together with the plunger, causing the edge of the valve, which has a protrusion at the tip, to open the flow control port provided in the seat. A proportional solenoid valve that opens and closes and allows a predetermined flow rate to flow from an inflow passage to an outflow passage, characterized in that a vertical hole opening at the tip of a protrusion at the tip of the valve and a horizontal hole communicating with the circumferential surface of the protrusion are provided. proportional solenoid valve.