JPH0322608Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The invention uses a movable iron core that is attracted to a fixed iron core by excitation of an electromagnetic coil to move the valve body and adjust the pressure in the outlet passage to the suction force. The present invention relates to an electromagnetically operated valve that can be controlled according to the conditions.

[Prior Art] Conventionally, there is one such electromagnetically operated valve as shown in FIG. 4, for example. In the figure, 1 is a valve body, in which a supply passage P communicates with a compressed air source as a pressure source, an outlet passage A communicates with an actuator, and a discharge passage E communicates with the atmosphere as a low pressure side. A valve body 2 that opens and closes the supply passage P or the discharge passage E by moving in the axial direction is provided inside. Reference numeral 3 denotes a solenoid attached to the body 1, which includes an electromagnetic coil 4 and a rod 6 integrally connected within a housing chamber 5 formed inside the electromagnetic coil 4.
The fixed iron core 8 houses a movable iron core 7 that is supported by and moves in the axial direction, and also has a fixed iron core 8 that attracts the movable iron core 7 with a force corresponding to the excitation current when the electromagnetic coil 4 is excited.

9 is a pressure chamber communicating with the outlet passage A, 10 is a spring housed in the pressure chamber 9, and the valve body 2 is pressed upward in the figure by the acting force based on the force of the spring 10 and the pressure of the pressure chamber 9, and the valve body 2 is connected to the movable iron core 7 so as to come into contact with the rod 6 and move together with the movable iron core 7. Note that 11 is a communication hole that communicates both ends of the movable iron core 7 of the accommodation chamber 5.

Next, when the electromagnetic coil 4 is discharged as shown in the figure, the valve body 2 is pressed upward in the figure by the force of the spring 10, closing the supply passage P, opening the discharge passage E, and opening the outlet passage A and the discharge passage. It communicates between E.

From this state, when the electromagnetic coil 4 is energized by applying a predetermined current, the movable iron core 7 is attracted and moved toward the fixed iron core 8 side, and at the same time, the valve body 2 is moved downward in the figure, and the discharge passage E is closed, the supply passage P is opened and communicated with the outlet passage A, and compressed air flows into the outlet passage A. Then, the pressure in the outlet passage A that is guided to the pressure chamber 9 and acts on the valve body 2 is transferred to the movable iron core 7.
If the valve body 2 rises more than it can overcome the suction force, the valve body 2
The movable iron core 7 moves upward in the figure to a position where the suction force, the force of the spring 10, and the acting force based on the increased pressure of the pressure chamber 9 are balanced, thereby reducing the opening between the supply passage P and the outlet passage A. , or close the supply passage P and open the exhaust passage E to exhaust the compressed air in the outlet passage A to suppress the pressure rise. Also, if the pressure in the outlet passage A decreases from this state, the valve body 2 and the movable iron Core 7
moves downward in the diagram to the equilibrium position between the suction force, the force of the spring 10, and the acting force based on the reduced pressure of the pressure chamber 9, and the opening degree between the outlet passage A and the discharge passage E is reduced or the discharge passage E is closed, the supply passage P is opened to suppress the pressure drop, and the outlet passage A is opened according to the suction force.
The pressure in the outlet passage A can be changed by controlling the pressure to , and by changing the excitation current to the electromagnetic coil 4.

[Problem that the invention attempts to solve]

However, in this case, when the pressure in the outlet passage A suddenly changes, the valve body 2 overstrokes due to the inertia of the rapidly moving valve body 2 and the movable iron core 7, resulting in excessive supply from the supply passage P or This results in excessive exhaust to the discharge passage E, further promoting pressure fluctuations in the outlet passage A, causing the valve body and the movable iron core 7 to repeatedly vibrate and rapidly move up and down, causing pulsations in the outlet passage A and reducing the pressure. There were problems that could not be well controlled.

The present invention solves this problem, and is an electromagnetically operated valve that suppresses the rapid movement of the movable iron core and valve body due to rapid fluctuations in the pressure in the outlet passage, and enables good control of the pressure in the outlet passage. It provides:

[Means for solving problems]

For this reason, the present invention includes a valve body having a supply passage communicating with a pressure source, an outlet passage communicating with an actuator, and a discharge passage communicating with a low pressure side, an electromagnetic coil, and a housing chamber formed inside the electromagnetic coil. The valve consists of a movable iron core that freely moves in the axial direction and a solenoid attached to the valve body, which has a fixed iron core that attracts the movable iron core in one direction in the axial direction with a force corresponding to the exciting current by excitation of an electromagnetic coil. Inside the main body, there is a suction force connected to the movable iron core so as to control the pressure of the outlet passage according to the suction force of the solenoid to the movable iron core, a spring force opposing the suction force, and an action based on the pressure of the outlet passage. A valve body is provided that is movable to a position in equilibrium with the force, an annular groove is provided on the outer periphery of the movable iron core of the solenoid, and an annular O-ring made of an elastic material is attached to the outer periphery. is attached to the annular groove so that the O-ring is in contact with the inner wall of the housing chamber and the inner periphery is spaced from the bottom wall of the annular groove, and the O-ring is provided with a notch formed by recessing the outer periphery to serve as a throttle passage.

[Effect]

Since the present invention is configured as described above, when the movable iron core moves, the O-ring moves integrally with the movable iron core when the side wall of the annular groove comes into contact with it, and if the moving speed is high, the O-ring will be cut. Due to the squeezing action of the notch,
The pressure on the moving direction side of the O-ring in the storage chamber increases, and negative pressure is generated on the opposite moving direction side, and the force due to this pressure difference is applied to the movable iron core so as to provide a brake, causing a sudden increase in the pressure in the outlet passage. Rapid movement of the movable iron core and valve body due to fluctuations can be suppressed, and the pressure in the outlet passage can be well controlled.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

Note that the same parts as in the case of FIG. 4 are given the same reference numerals, and the explanation thereof will be omitted, and only the different points will be explained.

The movable iron core 7 in the accommodation chamber 5 has an annular groove 12 on its outer periphery.
An annular O-ring 13 made of an elastic material such as synthetic rubber and having a width smaller than the groove width is inserted into the annular groove 12.
Attach to. The O-ring 13 attached to the annular groove 12 is arranged such that the outer circumference is in contact with the inner wall of the storage chamber 5 and there is a gap between the inner circumference and the bottom wall 12A of the annular groove 12. A cutout portion 14 serving as a throttle passage is formed in a recessed manner. Note that the communication hole 11 shown in FIG. 4 is not provided.

To explain this operation, when the movable iron core 7 moves together with the valve body 2, the O-ring 13 moves integrally with the movable iron core 7 when it comes into contact with the side wall of the annular groove 12.
If this moving speed is low, the notch 14 hardly causes a throttling action, but if the moving speed is high, the notch 14 creates a throttling action that causes the storage chamber 5 to
The pressure of the air inside increases on the moving direction side of the O-ring 13, and the pressure decreases on the opposite side of the moving direction, creating negative pressure, and the force due to this pressure difference is applied to the movable iron core 7 to provide braking. In addition, the increased pressure is introduced into the annular groove 12 and presses the O-ring 13 radially outward against the inner wall of the storage chamber 5.
The frictional resistance increases, and the rapid movement of the movable iron core 7 and the valve body 2 is suppressed.

Therefore, even when the pressure in the outlet passage A suddenly changes, rapid vibrational movement of the movable iron core 7 and the valve body 2 is suppressed, and even if it occurs, it is rapidly attenuated, and the pressure in the outlet passage A is Large fluctuations are suppressed and the system quickly stabilizes.

Note that one embodiment shows a pressure reducing valve for gas, but
It can also be used for liquids.

[Effect of idea]

As described above, the present invention includes a valve body provided with a supply passage communicating with a pressure source, an outlet passage communicating with an actuator, and a discharge passage communicating with a low pressure side;
A fixed iron that is housed in an electromagnetic coil and a storage chamber formed inside the electromagnetic coil and is freely movable in the axial direction, and that attracts the movable iron core to one side in the axial direction by excitation of the electromagnetic coil with a force according to the exciting current. It consists of a solenoid that has a core and is attached to the valve body, and inside the valve body there is a solenoid connected to the movable iron core so as to control the pressure in the outlet passage according to the suction force to the movable iron core of the solenoid. A valve body is provided that is movable to a position in equilibrium with the spring force opposing the suction force and the acting force based on the pressure of the outlet passage.The movable iron core of the solenoid is provided with an annular groove on the outer periphery, and the width of the annular groove is greater than the width of the annular groove. A small annular O-ring made of an elastic material is installed in the annular groove in the width direction so that the outer periphery touches the inner wall of the housing chamber and the inner periphery leaves a gap with the bottom wall of the annular groove, and the outer periphery of the O-ring is formed with a depression. By providing a notch that serves as a throttle passage, rapid movement of the movable iron core and valve body due to rapid fluctuations in pressure in the outlet passage can be suppressed.
The pressure in the outlet passage can be well controlled.

In addition, the O-ring increases the frictional resistance because the increased pressure due to the throttling action of the notch is introduced into the annular groove and pressed against the inner wall of the housing chamber, making it possible to further speed up the movement of the movable iron core and valve body. It can be suppressed. Furthermore, O
The ring is inexpensive and easy to install, and the annular groove provided in the movable iron core does not require precision machining and has the advantage of being extremely easy to manufacture.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an electromagnetically operated valve showing an embodiment of the present invention, Fig. 2 is an enlarged sectional view of the main part of Fig. 1, and Fig. 3 is a sectional view taken along the line - in Fig. 2. FIG. 4 is a sectional view of a conventional electromagnetically operated valve. 2... Valve body, 4... Electromagnetic coil, 5... Accommodation chamber, 7...
Movable iron core, 8... Fixed iron core, 12... Annular groove, 13...
O-ring, 14...notch part.

Claims (1)

[Scope of utility model registration request] The valve body is provided with a supply passage communicating with the pressure source, an outlet passage communicating with the actuator, and a discharge passage communicating with the low-pressure side, an electromagnetic coil, and a housing chamber formed inside the electromagnetic coil so that the valve body can be freely moved in the axial direction. It consists of a moving movable iron core and a solenoid attached to the valve body, which has a fixed iron core that attracts the movable iron core in one direction in the axial direction with a force corresponding to the exciting current by excitation of an electromagnetic coil, and an outlet inside the valve body. It is connected to the movable iron core so that the pressure in the passage is controlled according to the suction force on the movable iron core of the solenoid, and the suction force is brought to an equilibrium position with the acting force based on the opposing spring force and the pressure in the outlet passage. A movable valve body is provided, an annular groove is provided on the outer periphery of the movable iron core of the solenoid, and an annular O-ring made of an elastic material is smaller in the width direction than the groove width of the annular groove, and the outer periphery is on the wall of the accommodation chamber. The electromagnetic operated valve is mounted in an annular groove so that the inner periphery is in contact with the bottom wall of the annular groove, and there is a gap between the inner periphery and the bottom wall of the annular groove, and the O-ring has a notch formed on the outer periphery to serve as a throttle passage.