JP2523796Y2 - Electromagnetic flow control valve - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The invention relates to a flow control valve using an electromagnetic solenoid, and more particularly to a valve having improved valve closing response.

[Prior Art] As such an electromagnetic flow control valve, a core wound around an electromagnetic solenoid, a first passage formed in an axis portion of the core, and a communication with the first passage via a valve seat are formed. Normally open, which includes a second passage, a needle valve provided to be able to advance and retreat the axial center of the core, and a plunger provided around the outer portion of the core of the needle valve. The format is well known. It is also known that the second passage and a core end face facing the plunger communicate with each other through a pressure cancel passage in order to increase the responsiveness at the time of opening and closing the valve.

[Problems to be Solved by the Invention] By the way, for example, in the case of a normally open type in which the first passage side is set to a high pressure and the second passage side is set to a low pressure, when the electromagnetic solenoid is energized, it is electromagnetically attracted to the core and the needle valve is set. Close, but at this time the second with the movement of the plunger
The increase in the internal pressure on the passage side is canceled by part of the fluid flowing out toward the plunger through the pressure cancel passage. However, since the opening area at the outlet of the pressure cancel passage is relatively small, the pressure of the fluid flowing out of the outlet significantly increases near the outlet and acts as a fluid resistance. The speed of the moving fluid is reduced, and the moving speed of the plunger is correspondingly reduced, so that the time required for seating the needle valve is increased. As a result, there is a possibility that the accuracy of the flow rate control is reduced by delaying the valve closing. Therefore, it is desired to increase the valve closing response. The present invention satisfies such a demand.

Means for Solving the Problems In order to solve the above problems, an electromagnetic flow control valve according to the present invention includes a core wound around an electromagnetic solenoid, a plunger that can be electromagnetically attracted to an end of the core, and a shaft of the core. A first passage formed in the core, a second passage formed in communication with the first passage via a valve seat, and a pressure opening in the end face on the core side facing the plunger and communicating with the second passage side. In a normally open type electromagnetic flow control valve including a cancel passage and a valve provided so as to be able to contact and separate a valve seat and to move integrally with a plunger, an annular groove is provided on an end face on a core side facing the plunger. It is characterized in that the annular groove communicates with the pressure cancel passage. Here, the end surface on the core side is an end surface on at least one of the core and a member integrated with the core and functioning similarly to the core.

[Action of the Invention] When the electromagnetic solenoid is energized, the plunger is attracted to the end face on the core side, and the valve is seated on the valve seat. At this time, as the plunger moves, the pressure of the fluid in the portion sandwiched between the plunger and the core increases, but the increase in the internal pressure is canceled by part of the fluid passing through the pressure cancel passage and flowing out to the second passage side. Is done. At this time, the annular groove formed on the end face of the core holder guides the pressure cancel passage to promote the outflow of the fluid, so that the rise in the internal pressure is quickly canceled and the movement of the plunger is accelerated. As a result, the valve is quickly seated and the valve closing time is shortened, so that the valve closing response is improved.

FIG. 1 to FIG. 3 show an embodiment. FIG. 1 shows an entire cross section, and an electromagnetic solenoid 2 accommodated in a case 1 is shown.
A part of the core 3 is fitted to the inner periphery of the. The solenoid inner part 4 of the core 3 is fitted into a core holder 5 previously fitted to the electromagnetic solenoid 2. A through hole 6 is formed at the axial center of the core 3, and a valve seat 7 is formed at one end of the through hole 6.
An orifice 7a formed on one end face is fitted. A portion of the through hole 6 below the valve seat 7 is the first passage 8.
And is connected via a filter 9 to a pressing side (not shown) of, for example, an oil pump. The first passage 8 is the core 3
And a second passage 10 formed laterally in the shape of a lateral hole in communication with the through hole 6 on the side surface at the lower end. Further, a distal end 12 of a needle valve 11 that can advance and retreat in the second passage 10 can be seated on the valve seat 7. A plunger 13 is attached to the outer periphery of a portion of the needle valve 11 protruding outward from the end of the solenoid inner portion 4. When the valve is opened, a slight clearance is formed between the plunger 13 and the end surface 14 of the solenoid inner portion 4 of the core 3.

Furthermore, the end face 15 of the core holder 5 surrounding the end face 14
As shown in FIG. 2 in which the main part is enlarged and a part is cut away, and FIG. 3 in which the cross section of the end faces 14 and 15 is further enlarged, as shown in FIG. Are formed. The annular groove 16 is formed between the core holder 5 and the core holder 5 when the core 3 is fitted to the core holder 5 by notching a portion of the inner peripheral surface of the core holder 5 near the end face 15. The pressure cancel passage 17 is a groove formed in advance by partially recessing the outer surface of the core 3 in a lengthwise direction into a substantially U-shaped cross section when the core 3 is fitted to the core holder 5.
It is formed along 3a. The inlet portion 17a of the pressure cancellation passage 17 communicates with the annular groove 16, and as shown in FIG.
It communicates with the annular groove 16 and the space 18 formed by the plunger 13 and the end faces 14 and 15. The outlet side of the pressure cancellation passage 17 communicates with the second passage 10. A return spring 19 is provided between the core 3 and the plunger 13. The clearance of the plunger 13 with respect to the core 3 can be adjusted by a two-stage adjustment bolt 20 made of a non-magnetic material.

One end of the mounting part 21 of the adjustment bolt 20 is the plunger 13
A bush 23 is provided which extends to the outer peripheral side of the bush holder 22 and has a bush 23 to which the plunger 13 slides.
The sliding surface of the bush 23 with the plunger 13 is formed with a non-magnetic layer such as a fluororesin, and forms a kind of air gap for preventing the influence of residual magnetism. The outer circumferences of the bush holder 22 and the core holder 5 and the electromagnetic solenoid 2
A non-magnetic cylinder 25 is interposed between the inner circumferences of the bobbins 24. A magnetic plate 26 is interposed between one end surface of the bobbin 24 and the case 1. Electric power is supplied to the electromagnetic solenoid 2 from a lead wire 27 that passes through the magnetic plate 26.

Next, the operation of the present embodiment will be described. FIG. 1 shows a valve open state, in which the needle valve 11 is pushed up by the return spring 19 and the tip end 12 is separated from the valve seat 7, so that the first passage 8 and the second passage 10 pass through the valve seat 7. Communicating.

Here, when the electromagnetic solenoid 2 is energized, a closed magnetic path is formed between the electromagnetic solenoid 2-the core holder 5-the core 3-the plunger 13-the bush holder 22-the mounting portion 21-the magnetic plate 26-the case 1-the electromagnetic solenoid 2. So
The plunger 13 is sucked into the end face 14 of the core holder 5 and the tip
The valve seat 12 is seated on the valve seat 7 to close the valve and cut off between the first passage 8 and the second passage 10. At this time, as the plunger 13 moves, the internal pressure in the space 18 increases, but this increase is canceled by a part of the fluid flowing out of the pressure cancel passage 17 to the second passage 10 side. At this time, the fluid flowing toward the pressure cancel passage 17 formed between the end faces 14 and 15 of the core 3 and the core holder 5 is guided into the annular groove 16 formed substantially concentrically with the plunger 13 and smoothly enters the inlet. Since the fluid is guided to the portion 17, the fluid can quickly flow out of the pressure canceling passage 17, and the rise in the internal pressure is quickly canceled, so that the movement of the plunger 13 becomes faster. As a result, the tip 12 of the needle valve 11 can also be quickly seated on the valve seat 7, and the valve closing time is shortened, so that the valve closing response is improved.

When the power supply to the electromagnetic solenoid 2 is stopped, the closed magnetic circuit disappears. Therefore, the plunger 13 is moved upward in the figure by the fluid pressure of the first passage 8 and the return spring 19, and the tip 12 is separated from the valve seat 7 to be unseated. Open the valve.

FIG. 4 is a graph showing measured response times of the product of the present embodiment having the annular groove 16 and the comparative product having no annular groove 16 when the valve is closed. In both the comparative example and the present embodiment, the measurement samples are samplers A to C in which the orifices 7a are changed so that the orifice diameters are different from large, medium and small, respectively, and each sample is composed of a plurality of samples having the same orifice diameter. . FIG. 4 is a graph in which the valve closing operation is performed under the same conditions for each sample, and the time required to complete the valve closing is displayed in a range of variation for each sample. As is clear from this figure, it is clear that the present embodiment can shorten the response time regardless of the size of the orifice diameter and can obtain a high-speed response. Therefore, by realizing such a high-speed response, the flow rate can be controlled with higher precision, which is suitable for use in, for example, a control device of a high-performance automobile engine.

[Effects of the Invention] In the present invention, the annular groove is provided on the end face on the core side facing the plunger, and the annular groove communicates with the pressure canceling passage provided on the core side. As a result, the moving speed of the fluid passing through the inside of the pressure cancel passage can be increased. Therefore, the pressure can be canceled quickly and the plunger can be moved quickly, so that the normally open type valve can be quickly seated on the valve seat. Therefore, valve closing response can be enhanced, and highly accurate flow control can be performed.

[Brief description of the drawings]

1 to 3 show an embodiment, and FIG. 1 is a full sectional view,
FIG. 2 is an enlarged view of a main part partially cut away, and FIG. 3 is an enlarged sectional view of the main part. FIG. 4 is a response time comparison graph between the present embodiment and a comparative example. (Explanation of reference numerals) 2 ... Electromagnetic solenoid, 3 ... Core, 5 ... Core holder, 7 ... Valve seat, 8 ... First passage, 10 ... Second
Passageway, 11 Needle valve, 13 Plunger, 16
... annular groove, 17 ... pressure cancel passage.

Claims (1)

(57) [Scope of request for utility model registration] 1. A core wound around an electromagnetic solenoid, a plunger capable of being electromagnetically attracted to an end of the core, a first passage formed in a shaft center portion of the core, and a valve seat in the first passage. A second passage formed in communication with the valve, a pressure canceling passage opened in the end face on the core side facing the plunger and communicating with the second passage, and a valve provided so as to be able to contact and separate the valve seat and move integrally with the plunger. 1. A normally open type electromagnetic flow control valve, comprising: an annular groove provided in an end face on a core side facing the plunger, and communicating the annular groove with a pressure canceling passage.