JPH0670479B2 - Electromagnetic flow control valve - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow control valve used in a fluid circuit for moving a fluid device as intended, and more particularly to a force for biasing a valve body toward a valve seat. The present invention relates to an electromagnetic flow control valve capable of changing a flow rate or pressure accurately and continuously by controlling as necessary.

(Prior Art) A flow control valve is used to adjust the flow rate of a fluid circuit to adjust the movement speed of an actuator and the rate of pressure increase. Its performance is that the flow rate adjustment range is large. , Fine adjustment is possible, and stable and continuous characteristics are required.

The most common is the needle valve. This uses a screw to move a needle valve having a conical tip forward or backward to change the valve opening. However, it has many problems due to its structure. It is difficult to eliminate looseness in the screw part, inconsistency of the axis line between the orifice and the needle valve, etc., and the change in screw rotation angle and valve opening are not constant, and accurate flow rate adjustment or pressure adjustment is not possible. There was a drawback to say. Further, the wear of the threaded portion was also a big problem.

On the other hand, as a flow rate control valve developed to solve the above mechanical problem, for example, there is a valve shown in FIG. 3 (a).
In this valve, a valve seat member 2 having a valve seat 2a having a substantially conical inner surface is fixed to an inlet 1a for pressurized fluid of a housing 1, and a valve body 3 capable of making line contact with the inner surface of the valve seat 2a is The flow rate of the pressurized fluid flowing between the valve seat and the valve body is controlled by shifting it by the throttle adjusting plate 4 which can shift in the axial direction of the seat member 2. In order to shift the diaphragm adjusting plate 4 made of a magnetic material in the axial direction, the magnetic force of the electromagnet 5 arranged facing the diaphragm adjusting plate 4 and spaced around the valve seat member 2 is changed to adjust the adjusting plate 4. It is sufficient to change the suction force that acts on. Therefore, by changing the current or voltage acting on the coil forming the electromagnet, it is possible to continuously adjust the force for biasing the valve body toward the valve seat (hereinafter referred to as the throttling force), which is easy to operate. There is no mechanical problem such as looseness of the screw part.

(Problems to be Solved by the Invention) However, in the electromagnetic flow control valve having the above-described configuration, when the throttle adjusting plate 4 comes into contact with the spherical valve body 3, the throttle adjusting plate 4 is provided with the axis line of the valve seat member 2. There is a tendency not to be perpendicular to the direction but to contact with a certain inclination, and since this inclination changes each time the flow rate is adjusted and is not constant, the flow rate or pressure of the pressurized fluid discharged from the discharge port 1b fluctuates, and There is a drawback that it is difficult to control the flow rate or pressure of the pressurized fluid. Further, since the diaphragm adjusting plate 4 is apt to cause self-excited vibration and causes oscillation when performing the foot-back control for the flow control valve, there is a problem that the gain of the loop cannot be set to a large value. .

Such a problem is, for example, as shown in FIG.
Two electromagnetic flow control valves (20a, 20b) described above are used, and these valves are electrically connected to each other via the voltage control means 21 so that the voltages acting on the respective valves 20a, 20b are opposite to each other. This is particularly important in a servo valve that changes the set pressure P by adjusting the throttling forces f ₁ and f ₂ in the interlocked manner.

Therefore, in order to prevent self-excited vibration between the diaphragm adjusting plate 4 and the spherical valve body 3 due to so-called dance, the axial gap formed between the diaphragm adjusting plate 4 and the sealing member 6 is reduced. It may be possible to set it so that the diaphragm adjusting plate does not easily vibrate around the spherical valve body, but the movable range of the valve body 3 becomes small, and it becomes difficult to control the valve body. This means that the response characteristic is deteriorated when two valves are combined and used as a servo valve.

In addition, in this conventional technique, when the valve is closed against the applied pressure of the pressurized fluid flowing into the valve seat member 2, the throttle adjusting plate 4 collides with the electromagnet 5 or the electromagnet housing and the valve body 3 Has a disadvantage in that it collides with the valve seat 2a, a relatively large noise is generated, and durability is unavoidably reduced.

(Means for Solving Problems) In order to solve these problems, in the electromagnetic type flow control valve of the present invention, in particular, a buffer member made of rubber or a rubber-like elastic sheet is made to face the diaphragm adjusting plate to serve as the driving means. An end surface of the buffer member facing the diaphragm adjusting plate is provided so as to project in the axial direction from an end surface of the driving unit facing the diaphragm adjusting plate.

More preferably, a low-elasticity sheet is arranged between the diaphragm adjustment plate and the sealing member.

(Operation) Therefore, in the electromagnetic type flow control valve configured as described above, in order to control the flow rate or pressure of the pressurized fluid, an electric signal is applied to the electromagnet to shift the throttle adjusting plate in the axial direction. When adjusting the opening degree, the throttle adjusting plate presses the valve body toward the valve seat in the contact state with the spherical valve body, and also contacts the cushioning member made of rubber or a rubber-like elastic sheet. At this time, the throttle adjusting plate presses the valve element in the axial direction against the elastic force of the cushioning member and imparts a desired valve opening degree. On the other hand, since the throttle adjusting plate is in contact with the buffer member, it does not tilt or vibrate around the valve body, and as a result, the flow rate or pressure can always be controlled accurately.

Moreover, in this flow rate control valve, when the closing operation is performed, the throttle adjusting plate contacts the cushioning member, and the valve body is
Under the action of the cushioning member, the collision impact is sufficiently mitigated to come into contact with the valve seat, so that it is possible to effectively prevent a decrease in durability in addition to the generation of noise during the closing operation.

By the way, in this flow control valve, an electromagnet is arranged on the same side as the valve element and the valve seat with respect to the throttle adjusting plate, and the closing operation of the control valve is brought about by the suction action of the electromagnet. Therefore, even when the cushioning member has a so-called fatigue, it is possible to always surely realize the complete closing of the control valve.

Further, in this control valve, when a low-elasticity sheet is provided between the throttle adjusting plate and the sealing member,
It is also possible to effectively eliminate the vibration of the throttle adjustment plate due to the inertial force when the control valve is in the open position. From this point as well, collision noise can be effectively prevented and the flow rate or pressure can still be reduced. The control accuracy of can be effectively improved.

(Embodiment) An electromagnetic flow control valve of the present invention will be described below with reference to the drawings. In the drawings, the same symbols as those in FIG. 3 denote the same components.

FIG. 1 (a) shows a preferred embodiment of the present invention. Reference numeral 1 denotes a housing, which has an inlet 1a for pressurized fluid and an outlet 1b. The valve seat member 2 is fixed to the inlet 1a of the housing 1. In addition, the O-ring 8a is attached to the valve seat member 2 and
1a and the valve seat member 2 are sealed. This valve seat member 2 is provided with a mouthpiece 9a so that pressurized fluid can be supplied to one end reliably and easily.
Is a hollow member having a valve seat 2a with which the spherical valve body 3 abuts on the other end, and the pressurized fluid flows in the hollow passage. In this embodiment, the mouthpiece portion 9a and the valve seat 2a are formed integrally with the valve seat member 2, but they may be formed separately.

The valve seat 2a has a substantially conical inner surface so as to make line contact with the valve body 3. Further, in consideration of the fact that a steel ball is usually used as the valve element, it is advantageous to form the valve seat 2a with a ceramic of alumina or silicon carbide in order to improve the wear resistance of the contact portion. . On the other hand, if a valve body made of plastic, preferably acetal resin, is used instead of a steel ball, the valve body can be made lighter. In addition, the noise generated when the valve body collides with the valve seat or the throttle adjusting plate can be almost eliminated, and the life of the contact portion can be improved, and the chemical resistance is great. Therefore, the control valve including the valve body 3 may be appropriately selected according to the pressurized fluid used.

The electromagnet 5 and the casing 10 are spaced apart from the valve seat member 2.
The drive means is fixed to the housing 1 concentrically with the axis of the valve seat member. Therefore, the pressurized fluid supplied from the mouthpiece portion 9a passes through the hollow valve seat member, passes through the opening formed between the valve seat 2a and the valve body 3, and is connected to the valve seat member and the drive means. It is discharged from the discharge port 1b through the gap between them. Housing 1
The casing 10 that is fixedly attached to and supports the electromagnet has an opening on the end surface facing the diaphragm adjusting plate 4, and accommodates a buffer member 12 made of rubber or a rubber-like elastic material in the opening.
At one end surface of the cushioning member 12, the throttle adjusting plate 4 moves the valve body 3 into the valve seat 2a.
When the valve is completely contacted with the valve, that is, from 0% of the valve opening to 100% of the valve opening, the throttle adjusting plate 4 directly contacts the end surface of the drive means, in this embodiment, the end surface of the casing 10. Project in the axial direction so as not to come into contact. In addition, cushioning member
The use of rubber or a rubber-like elastic material having a degree of compliance similar to that of general-purpose rubber is advantageous in terms of durability and that the movement of the diaphragm adjusting plate 4 in the axial direction is not hindered. The thickness is between the recessed portion 11 formed in the sealing member 6 and the diaphragm adjustment plate 4 made of a magnetic material, which accommodates the diaphragm adjustment plate so that the diaphragm adjustment plate can be displaced in the axial direction when the valve opening is 0%. The axial gap d (see FIG. 1 (b)),
In other words, it is preferable that the distance is substantially the same as the movement distance of the diaphragm adjusting plate 4 in the axial direction.

Therefore, even if an electric signal is applied to the electromagnet 5 constituting the driving means to shift the throttle adjusting plate 4 in the valve seat direction and press the valve body 3 in the valve seat direction, the spherical valve body 3 is abutted. Since the diaphragm adjusting plate 4 is in contact with the cushioning member 12 over the entire circumference at its peripheral portion, it does not deviate in a direction other than the axial direction.
Further, there is no vibration around the valve body 3.

The O-ring 8b is inserted into the open end of the housing 1, and the sealing member 6 is sealed and fixed to the housing using the fastening bolt 7. In this embodiment, the recess 11 is provided in the sealing member 6 in order to allow the movement of the diaphragm adjusting plate 4 in the axial direction. However, the diaphragm adjusting plate 4 can be moved in the axial direction in the housing 1. In that case, the driving means is provided so as to deviate toward the introduction port 1a side in accordance with the moving distance of the diaphragm adjusting plate.

Further, in order to absorb the inertial force acting on the diaphragm adjusting plate 4,
In the concave portion 11 or on one side surface of the diaphragm adjusting plate facing the concave portion 11,
By disposing a low-elasticity sheet, for example, a urethane foam sheet, it is possible to absorb the inertial force and more reliably prevent vibration of the diaphragm adjusting plate.

The manner in which the flow rate (or pressure) of the pressurized fluid is controlled using the electromagnetic flow control valve having such a configuration will be described below. In addition, it is assumed that a connection pipe connected to a supply source of the pressurized fluid, for example, an air compressor (not shown) is seal-connected to the mouthpiece portion 9 of the control valve. Pressurized air from the air compressor passes through the hollow part of the valve seat member,
The valve body 3 is pushed to the right in FIG.
Other connection pipe (not shown) connected to the via the base 9b
Flows in. In order to limit the flow rate of the pressurized air flowing into the other connecting pipe, an electric signal is applied to the electromagnet 5 constituting the driving means to move the throttle adjusting plate 4 in the valve seat direction, that is, to the left in FIG. 1 (a). Move towards. The diaphragm adjusting plate 4 presses the valve body 3 leftward against the force of the pressurized air acting on the valve body 3, and the force exerted on the diaphragm adjusting plate by the electromagnet 5 and the buffer member 12 and the valve body 3 are increased. It stops at the position where the force acting on it balances. Therefore, the valve opening degree decreases and the flow rate of the pressurized air flowing through the control valve decreases, so that a desired flow rate (or pressure) can be provided. At this time, the diaphragm adjusting plate 4 is in contact with the valve body 3 and also with the buffer member 12 at the peripheral edge thereof, so that the diaphragm adjusting plate 4 vibrates around the valve body 3 or in a direction other than the axial direction. There is no shift. In this example,
Although the buffer member 12 is fixed to the electromagnet 5 by a known fixing means such as adhesion, it may be fixed to the peripheral surface of the opening of the casing 10.

FIG. 2 (a) shows another embodiment of the present invention. This embodiment also has substantially the same structure as the embodiment shown in FIG. 1 (a), except that the housing 1 is provided with an inlet 1a for pressurized fluid and the outlet 1b is provided in the sealing member 6. . The pressurized fluid guided from the valve seat member 2 into the housing 1 passes through the throttle adjusting plate 4 in the axial direction, at least one, at least four through holes 14 in this embodiment, and the discharge port. It is led to 1b (see FIG. 2 (b)).

Even in the conventional electromagnetic flow control valve, it is possible to provide a through hole penetrating the throttle adjusting plate in the axial direction and discharge the pressurized fluid from the discharge port provided in the sealing member. The energy of the pressurized fluid passing through the adjusting plate vibrates the throttle adjusting plate violently around the valve body, so that the function as the flow control valve cannot be achieved. On the other hand, in the electromagnetic type flow control valve of the present invention, the vibration and the deviation of the throttle adjusting plate 4 other than in the axial direction are blocked by the cushioning member 12, so that the throttle adjusting plate vibrates or moves in a direction other than the predetermined direction. There is no shift.

Also in the embodiment shown in FIG. 2 (a), in order to absorb the inertial force acting on the diaphragm adjusting plate 4, a low elasticity sheet such as a urethane foam sheet is provided in the gap between the diaphragm adjusting plate 4 and the recess 11. Needless to say, it may be provided.

Furthermore, the outlet 1b of the valve shown in FIG. 2 (a) is connected to the inlet of another electromagnetic type flow control valve having substantially the same configuration, and the outlet (1b) is connected to a port (not shown). No.) is connected to this port, a connecting pipe that supplies pressurized air to an actuator such as an air cylinder is connected to this port, and the electric signal that acts on the electromagnet of each valve is controlled to apply the actuator action. It is also possible to freely control the pressure of the compressed air.

(Effects of the Invention) As described in detail above, in the electromagnetic flow control valve of the present invention, the cushioning member made of rubber or a rubber-like elastic sheet is provided on the drive means so as to face the diaphragm adjusting plate, and the end face of the cushioning member is provided. Protrudes in the axial direction from the end surface of the drive means in the direction of the diaphragm adjusting plate, so that the diaphragm adjusting plate abuts on the valve body and always abuts on the cushioning member and is displaced in the axial direction. Therefore, the throttle adjustment plate faithfully shifts in the axial direction, presses the valve element in the valve seat direction, and does not shift in any direction other than the axial direction.
Further, it is possible to obtain an electromagnetic flow control valve having excellent static and dynamic characteristics, which does not vibrate around the valve body and has various problems caused by the vibration of the diaphragm adjusting plate. Further, even if a through hole is provided through the throttle adjusting plate and the pressurized fluid flows through the through hole, the diaphragm adjusting plate does not vibrate due to the energy of the pressurized fluid. The exhaust port does not have to be provided so as to intersect with the axis of the seat member, and the degree of freedom in design is increased, for example, the size of the valve, especially the outer diameter can be reduced. Furthermore, the valves can be integrally connected and used as if they were a single servo valve.

Further, here, at the time of the closing operation of the flow control valve, the throttle adjusting plate abuts on the cushioning member, and the valve body abuts on the valve seat in a state in which the impact shock is sufficiently mitigated by the cushioning member.
It is possible to effectively prevent the generation of collision noise during the closing operation, and it is also possible to improve the durability of the valve body, the valve seat, and the like.

Furthermore, since the flow control valve causes the valve body to closely contact the valve seat under the action of the magnetic attraction force of the electromagnet, even if the cushion member has a setback, the flow control valve is not affected by it. Complete closure of the valve can be reliably achieved.

Here, when a low-elasticity sheet is provided between the throttle adjustment plate and the sealing member, vibration of the throttle adjustment valve when the control valve is in the open position is prevented by the low-elasticity sheet. In addition to preventing collision noise, the flow rate or pressure control accuracy can be further enhanced.

[Brief description of drawings]

FIG. 1 (a) is a sectional front view showing an electromagnetic flow control valve of the present invention, and FIG. 1 (b) is an explanatory view showing a part of FIG. 1 (a) extracted and shown. 2A is a sectional front view showing another embodiment of the present invention, FIG. 2B is a plan view of a diaphragm adjusting plate used in the embodiment of FIG. 2A, and FIG. ) And (b) are a sectional view showing a known electromagnetic type flow control valve and a diagram showing an operating principle of a servo valve using the electromagnetic flow control valve. 1 ... Housing, 1a ... Inlet port 1b ... Outlet port, 2 ... Valve seat member 3 ... Valve body, 4 ... Throttle adjusting plate 5 ... Electromagnet, 6 ... Sealing member 7 ... Fastening bolt , 8a, 8b …… O-ring 9a, 9b …… Mouthpiece, 10 …… Casing 11 …… Recess, 12 …… Buffer member 14 …… Through hole

Claims (2)

[Claims] 1. A housing (1) having an inlet (1a) for pressurized fluid, and a valve seat (2a) attached to the inlet (1a) and extending inside the housing and having a substantially conical inner surface. (2) having a valve seat, a spherical valve body (3) capable of making line contact with the valve seat (2a), and a valve seat (2a) via the valve body (3)
A diaphragm adjusting plate (4) made of a magnetic material, the diaphragm adjusting plate (4) being disposed so as to face each other and capable of being displaced in the axial direction of the valve seat member (2);
Secured to the housing (1) around the valve seat member (2),
A drive means having an electromagnet (5) for displacing the diaphragm adjustment plate (4) toward the valve seat, a sealing member (6) for sealing the open end of the housing (1), the housing (1) or a seal. In an electromagnetic flow control valve having a discharge port (1b) provided in a stop member (6), a buffer member (12) made of rubber or a rubber-like elastic sheet is made to face a diaphragm adjusting plate (4) to drive means. And an end surface of the buffer member (12) facing the diaphragm adjusting plate (4) is projected in the axial direction from an end surface of the driving means facing the diaphragm adjusting plate (4). Flow control valve. 2. A low-elasticity sheet is provided between the diaphragm adjusting plate (4) and the sealing member (6).
A flow control valve according to item.