JPS6141483Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a proportional flow control valve, particularly a proportional flow control valve for gases.

Conventional fluid flow control valves, particularly electromagnetic flow control valves for air, etc., generally have the following configuration.

In other words, this type of electromagnetic flow control valve has a movable core that is installed in a casing so as to be movable in the axial direction and moves in one direction from its original position when an electromagnetic coil is energized, and a movable core that is installed at the axis of the movable core. a shaft that is assembled to the tip of the shaft so that when the movable core is in the original position, the movable core seats on a valve seat provided in the housing, and when the movable core moves in one direction, the movable shaft moves away from the valve seat; Generally, a valve body is provided with a spring that biases the movable core and shaft in the other direction, and the flow rate of fluid passing through the valve body is controlled according to the value of current applied to the electromagnetic coil. It is a structure. In this type of flow control valve, the flow rate is controlled by controlling the opening degree of the movable valve element from the valve seat. Communication is formed between the chamber (primary valve chamber), the valve seat opening, the gap between the valve seat and the movable valve body, the outlet chamber (secondary valve chamber), and the fluid outlet.

Conventionally, in order to accurately control gas such as air, it has been required to have gas flow characteristics that correspond to or are proportional to the poppet valve opening. However, in the conventional valve configuration, the resistance of the flow path is large, and it is difficult to ensure a sufficient current for a given applied current or voltage. Therefore, in order to secure a given flow rate, it is necessary to increase the diameter of the suction port, the primary and secondary valve chambers, the valve seat opening diameter, etc., and as a result, a large-sized valve is required. There was a problem.

The purpose of this invention is to ensure a sufficient flow rate without increasing the diameter. That is, the basic structure of the proportional flow rate control valve of the present invention is to make the center of the opening of the valve seat eccentric from the center of the cross section of the primary valve chamber perpendicular to the poppet valve shaft.

The present invention will be explained in detail below.

The valve structure of the present invention makes the center of the valve seat opening eccentric with respect to the cross-sectional center of the intake chamber (primary valve chamber), which forms the flow path for guiding the fluid flowing in from the suction port to the valve seat opening. The fluid flow is facilitated and smoothed, preventing the formation of turbulence or vortices, thereby reducing the line resistance to the minimum when passing through the valve. In the conventional valve structure, the center C of the valve seat opening 25a and the center of the cross section 23a of the primary valve chamber are formed concentrically, and a vortex is generated when air flowing from the suction port heads toward the valve seat opening. It was found that the pipe resistance increased and a sufficient valve flow rate could not be obtained under a predetermined differential pressure.

According to the present invention, the above-mentioned main cause of increased pipe line resistance is eliminated by the basic configuration of the valve seat opening center and the primary valve chamber cross-sectional center being eccentric from each other. In the present invention, the suction port is desirably disposed substantially tangentially to the outer periphery of the primary valve chamber, but other mounting configurations are also possible.

As a result, in the present invention, as shown qualitatively in FIG. 3, with the same primary valve chamber, suction port, valve seat opening, etc., the valve body has a larger diameter than the conventional concentric structure. , it is possible to obtain better flow rate response for the same control applied current.

Hereinafter, the embodiments will be described with reference to the drawings.

FIG. 1 is a sectional view in the central axis direction showing an embodiment of the present invention. The electromagnetic proportional flow control valve 1 is
The casing 2 has a primary valve chamber 3 and a secondary valve chamber 4, and a valve seat 5 (equipped with a valve seat opening) that partitions both valve chambers, and a valve seat 5 that can be seated on the valve seat 5 and that can be seated in the valve opening direction. A movable valve body 6 that is movable (in the central axis direction) and a central shaft 7 that supports and controls the movable valve body 6 are the basic components of the valve portion.

The primary valve chamber 3 has _a circular cross section 3a centered at point _C3 in FIG. It forms a circular aperture centered on point _C5 , which is eccentric by _tX and _tY . A suction port 8 to the primary valve chamber 3 opens in a tangential direction to its cross-sectional outer circumference 3a, and a port (outlet) from the secondary valve chamber 4 opens in a tangential direction from its cross-sectional outer circumference.
9 is formed. The port 9 is preferably on the opposite side of the valve seat center _C5 from the port 8, but the mutual arrangement of the inlet and the outlet is such that they open tangentially to the respective valve chamber. , in any desired angular position and is not limited to the illustrated embodiment. In addition, an arrangement of the suction port and the outlet other than in the tangential direction of the valve chamber may be allowed as required. The degree of eccentricity is preferably such that the opening of the valve seat is inscribed in the outer periphery of the primary valve chamber. In this example, the primary valve chamber is placed on the opposite side of the valve seat from the movable valve body, which produces a favorable effect, but if the primary valve chamber is placed on the same side as the movable valve body, Similar effects can also be expected from the eccentric positions of the primary valve chamber cross section and the center of the valve seat opening.

Generally, it is sufficient to form the secondary valve chamber 4 concentrically with the valve seat opening center _C5 , but it can also be made eccentric by a certain amount like the primary valve chamber.

This eccentric arrangement of the primary valve chamber 3 and the center of the valve seat opening 5a produces particularly advantageous results, particularly in an electromagnetic proportional flow control valve as shown in FIG. That is, on the side of the secondary valve chamber 4 of the casing 2, the central shaft 7 passes through the bearing 12a, extends to the end of the electromagnetic coil 11, and is supported by passing through the bearing 12b, and the right end thereof is connected to the valve by the spring 17. It is biased in the closing direction. The spring 17 is supported by a blind screw 18 so that the urging force can be adjusted. central axis 7
A movable core (iron core) 10 is attached at least in a fixed axial position in the valve opening direction, and when the coil 11 is energized (preferably with a variable current value, and in some cases with a variable voltage value), the movable core (iron core) 10 moves in the valve opening direction with respect to the central axis 7. (towards the right in the figure).

The part that accommodates the coil 11 and the movable core 10 is
It is divided into a secondary valve chamber 4 by a partition wall 13, and a bearing 12
a simultaneously forms an airtight seal. Between the bearing 12a and the movable valve body 6, a bellows 14 (preferably made of Teflon) is arranged airtightly from the secondary valve chamber 4, and the inner chamber of the bellows 14 has a communication hole passing through the movable valve body 6. 15, it communicates with the primary valve chamber 3 and into the valve seat opening 5a. Both ends of the bellows 14 form flange portions 14a and 14b, respectively, and are airtightly fixed to the poppet valve 6 and the casing 2 via a locking tool 16 and a packing 17, respectively. Note that the locking tool 16 has a communication path 16a with the communication hole 15.

The seating surface of the movable valve body 6 against the valve seat 5 is preferably coated with an elastic material to contribute to sealing when the valve is opened. The details of the electromagnetic coil 11 are outside the scope of the invention of the present application, so a description thereof will be omitted.

The operation of the electromagnetic proportional flow control valve 1 configured as described above is as follows. For example, when used as a control valve for an intake system of an internal combustion engine, the suction port 8 is connected to the atmospheric pressure side (high pressure side) and the outlet 9 is connected to the negative pressure side. In this case, when a DC control current is gradually applied to the coil, the movable core receives a corresponding repulsive force in the valve opening direction from the coil magnetic field. The central shaft 7 (therefore, the movable valve body 6) remains stopped (valve closed) due to the frictional resistance and the like. When the current value increases further,
The movable valve body begins to move to the right and the valve begins to open.

Further, as the current value increases, the movable valve body moves to the right, the valve opening increases accordingly, and the flow rate increases proportionally. At this time, the bellows 14 acts auxiliary to control the valve, and receives pressure in the bellows 14 through the communication hole 15 corresponding to pressure fluctuations in the portion of the valve seat opening 5a. As a result, the differential pressure between the bellows and the pressure in the secondary valve chamber decreases, and a force in the valve opening direction is exerted on the poppet valve. In other words, the bellows has an acting force in the valve opening direction corresponding to the negative pressure at the valve seat opening 5a. , contributes to stabilizing and improving the accuracy of valve opening control. This relationship, ie, the valve flow rate responsiveness to the control signal (current value), is schematically shown by curve A in the graph of FIG. On the other hand, valves with the same diameter of each part without eccentric arrangement only exhibit response characteristics as shown by dotted line B, as an example.

As described above, in the present invention, it is possible to obtain a proportional flow rate control valve with better response characteristics (or sensitivity) to input signals in a control valve having a fixed diameter for each part. Therefore, for a certain maximum allowable flow rate, it is sufficient to use valves with considerably smaller diameters for each part than in conventional methods, resulting in smaller size, lighter weight, lower costs, and miniaturization of control signals (current, voltage). . In addition, as shown in FIG. 3, the present invention provides good linearity over a relatively wide range.

Naturally, the present invention can also be applied to control valves in which the poppet valve opens when no signal is applied and moves in the valve closing direction as the signal increases.

Note that the electromagnetic control mechanism is suitable for the most precise control, but it is not limited to the direct axial drive type as in this example, and the rotational drive (electromagnetic type, etc.) can be mechanically controlled by a movable valve body or a straight line of the central axis. It is also possible to adopt an indirect linear drive system that converts the signal into motion, and it is also naturally possible to use other control media (such as fluid pressure) instead of electric signals. However, whichever control mechanism is adopted, the present invention is particularly effective in small flow control valves that are controlled by minute control signals or operating forces.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view in the central axis direction showing an embodiment of the present invention, FIG. 2 is a cross-sectional view taken from FIG. 1, and FIG. 3 is a graph showing valve response characteristics of the present invention and the conventional method. are shown respectively. In Fig. 3, curve A: valve of the present invention, curve B: conventional method. 1...Proportional flow control valve, 2...Casing, 3
...Primary valve chamber ( _C3 primary valve chamber center), 4...Secondary valve chamber, 5...Valve seat (5a valve seat opening, _C5 valve seat opening center), 6...Movable valve body, 7... Central axis, 8, 9...
...port, 10...movable core, 11...coil,
14...Peroz, 17...Spring.

Claims (1)

[Claims for Utility Model Registration] (1) A casing in which each port is provided as a primary valve chamber and a secondary valve chamber, respectively, and a valve seat that divides the inside of the casing into a primary valve chamber and a secondary valve chamber; It consists of a movable valve body that can sit on the valve seat and is movable in a direction away from and/or toward the valve seat in response to a control signal by a control mechanism, and a central shaft that supports and controls the movable valve body, and a central shaft that supports and controls the movable valve body. In a proportional flow control valve of the type that controls the flow rate of fluid passing through the opening of the valve seat in response to a control signal to the mechanism, the center of the cross section perpendicular to the center axis of the movable valve body of the primary valve chamber is the valve seat opening. Proportional flow control valve formed eccentrically from the center of the cross section. (2) The control mechanism includes a core that is axially fixedly disposed on the central shaft, is assembled in the casing so as to be axially movable, and moves from its original position in the valve opening direction when an electromagnetic coil is energized; Registration of a utility model consisting of an electromagnetic coil arranged in a casing concentrically with the movable core and a spring that biases the movable valve element in the valve opening direction, and which controls the flow rate according to an electric signal to the electromagnetic coil. The valve according to claim 1.