JP2004011735A - Solenoid valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To smoothly actuate a solenoid valve by securely exhausting air from an exhaust passage of the solenoid valve. <P>SOLUTION: In a containing hole 16 formed in a valve casing 20, a main valve shaft 17 is provided to be capable of reciprocating in an axial direction. Output ports 24 and 25 are changed by the main valve shaft 17 to a feed port 21 and exhaust ports 22 and 23. A movable core 36 reciprocates in an axial direction by energization of a solenoid part 32 installed on the valve casing 20 to a coil 33, and a pilot valve interlocked with the movable core 36 changes an output passage communicated with an air pressure chamber 29 to a feed passage 39 communicated with the feed port 21 and an exhaust passage 42 to be communicated. In the exhaust passage 42, a filter 52 to prohibit inflow of dust into the exhaust passage 42 is incorporated. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a solenoid valve operated by a solenoid, and more particularly to a solenoid valve which is useful when applied to a pilot operation type in which a main valve shaft is operated by a pilot pressure generated by a direct-acting solenoid valve.
[0002]
[Prior art]
Directional control valves that control the direction of air flow control the supply and stop of air pressure to the pneumatic circuit, control the supply and discharge of air pressure, control the switching of the air pressure supply direction for reciprocating cylinders, etc. And two-position valves having two or more valve switching states and three-position valves having three switching states. As such a directional control valve, a pilot pressure is supplied to the main valve shaft or stopped by a direct acting three-port solenoid valve or a pilot valve that is operated by an electromagnet, that is, a movable iron core of a solenoid. There is a pilot-operated indirect-acting solenoid valve in which the main valve shaft is switched by a valve.
[0003]
This indirectly actuated solenoid valve has the advantage that the main valve shaft, whose operating force is large, can be switched by the pilot pressure, and a single solenoid type solenoid valve that operates the main valve shaft with one electromagnet and two electromagnets There is a double solenoid type that operates the main valve shaft. In the single solenoid type two-position valve, the main valve shaft returns to the original position when the power to the electromagnet is released. On the other hand, in the double solenoid type two-position valve, the main valve shaft keeps the original position if the current to one electromagnet is released and the current to the other electromagnet is not supplied. Further, in the double solenoid type three-position valve, when energization of both electromagnets is released, the main valve shaft becomes the neutral position, and when one of the electromagnets is energized, the main valve shaft operates similarly to the two-position valve.
[0004]
On the other hand, since the above-mentioned pilot valve is a direct acting three-port valve, it can be used as a single solenoid valve.
[0005]
[Problems to be solved by the invention]
Both the single solenoid type and the double solenoid type may be used alone or may be used with multiple solenoid valves assembled and mounted on a bracket or block.The assembled type is called a manifold solenoid valve. Is The flow path is connected to each of the air supply port and the exhaust port that are switched by the main valve shaft regardless of whether they are used alone or of the manifold type. The opening of the exhaust passage of the dynamic three-port solenoid valve is formed in the valve casing, and the three-port solenoid valve is directly discharged from the solenoid valve to the outside. Also, when the pilot valve is used alone as a single-acting three-port solenoid valve, the exhaust passage is similarly discharged directly from the valve casing to the outside.
[0006]
For this reason, when foreign matter such as dust enters the exhaust passage of the pilot valve, exhaust from the exhaust passage is not reliably performed, and there is a problem that the pilot valve does not operate reliably at a predetermined timing. Further, since exhaust gas from the pilot block is directly discharged to the outside, there is a problem that the exhaust sound becomes noise.
[0007]
SUMMARY OF THE INVENTION It is an object of the present invention to operate a solenoid valve smoothly by reliably discharging air from an exhaust passage of the solenoid valve.
[0008]
Another object of the present invention is to suppress exhaust noise from a solenoid valve.
[0009]
[Means for Solving the Problems]
The solenoid valve according to the present invention is provided with a valve casing in which a receiving hole communicating with an air supply port, an output port, and an exhaust port is provided, and is provided in the receiving hole so as to be reciprocally movable in an axial direction. A main valve shaft for switching and communicating with the air port and the exhaust port, a solenoid unit attached to the valve casing and provided with a movable core that reciprocates in the axial direction by energizing the coil, and interlocked with the movable core. A pilot valve mounted on the valve casing and communicating with the output passage communicating with the air pressure chamber accommodating the piston between an air supply passage and an exhaust passage communicating with the air supply port; and a pilot valve provided in the exhaust passage. And a filter for preventing inflow of dust into the exhaust passage.
[0010]
Further, the solenoid valve of the present invention is provided with pistons at both ends of the main valve shaft, and has two pilot valves respectively operated by the solenoids in correspondence with two pneumatic chambers accommodating the respective pistons. Features. Further, the solenoid valve according to the present invention is characterized in that the main valve shaft moves to two or three positions.
[0011]
The solenoid valve of the present invention has an air supply passage having an open end formed in a first valve seat, and an open end formed in a second valve seat which is opposite to the first valve seat. An exhaust passage, and a valve casing formed with an output passage for guiding air flowing out of the air supply passage to an output portion, and a movable core attached to the valve casing and reciprocating in an axial direction by energizing a coil. A solenoid provided, an on-off valve provided on the movable iron core for opening and closing the first valve seat, and disposed in the valve casing so as to face the on-off valve, and driven by the movable iron core via an interlocking pin. A flapper valve for opening and closing the second valve seat; and a filter provided in the exhaust passage for preventing inflow of dust into the exhaust passage.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing a solenoid valve according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a part of FIG. 1 in an enlarged manner. As shown in FIG. 1, a plurality of solenoid valves 11 are attached to the manifold block 10 so as to face the width direction of the manifold block 10. In FIG. 1, among the plurality of solenoid valves attached to the manifold block 10, One is shown. The manifold block 10 is formed with an air supply passage 12 connected to an air pressure source and two exhaust passages 13 and 14 each extending in the longitudinal direction.
[0013]
The solenoid valve 11 has a substantially rectangular parallelepiped main valve block 15, and a main valve shaft 17 is housed in a housing hole 16 formed in the main valve block 15 so as to be able to reciprocate in the axial direction. A cover block 18 is fixed to one end of the main valve block 15, and a pilot block 19 is fixed to the other end. A valve casing 20 is formed by the main valve block 15, the cover block 18, and the pilot block 19. ing.
[0014]
The main valve block 15 is provided with an air supply port 21 for communicating the air supply passage 12 with the accommodation hole 16, and two exhaust ports 22 and 23 for communicating the two exhaust passages 13 and 14 with the accommodation hole 16, respectively. Is formed. The main valve block 15 further has an output port 24 formed at an intermediate position between the air supply port 21 and one exhaust port 22, and an output port 25 formed at an intermediate position between the air supply port 21 and the other exhaust port 23. Have been.
[0015]
As described above, when the output ports 24 and 25 are formed in the main valve block 15, a joint that supplies compressed air to a pneumatic operating device such as a pneumatic cylinder is attached to the main valve block 15. However, when a plurality of solenoid valves 11 are mounted on the manifold block 10, output ports 24 and 25 may be provided in the manifold block 10 so as to communicate with the housing holes 16 so as to correspond to the respective solenoid valves 11. .
[0016]
The main valve shaft 17 is provided with a plurality of valve elements 17a, and when the main valve shaft 17 moves to the first position at one end in one direction, as shown in FIG. Are in communication, and the output port 24 and the exhaust port 22 are in communication. On the other hand, when the main valve shaft 17 moves to the second position at the other direction end, the ports are switched, the air supply port 21 and the output port 24 are in communication, and the output port 25 and the exhaust port 23 is in communication.
[0017]
A piston 26 is arranged at one end of the main valve shaft 17, and a piston 27 having a larger diameter than the piston 26 is arranged at the other end. A pneumatic chamber 28 is formed by the cover block 18 and the main valve block 15 to guide the piston 26 slidably in the axial direction. The pilot block 19 and the main valve block 15 guide the piston 27 slidably in the axial direction. A pneumatic chamber 29 is formed.
[0018]
The air supply port 21 communicates with the pneumatic chamber 28 through an air supply passage 31 formed in the main valve block 15. If compressed air is supplied to the air supply port 21, compressed air is always supplied to the air pressure chamber 28. Thus, a thrust toward the first position is applied to the main valve shaft 17. However, if a compression coil spring is incorporated in the pneumatic chamber 28 and this is used as a spring accommodating chamber, thrust in the same direction can be applied by the compression coil spring.
[0019]
A solenoid part 32 is attached to the pilot block 19. As shown in FIG. 1, the solenoid part 32 has a bobbin 34 around which a coil 33 is wound, and a fixed iron core 35 is attached inside the bobbin 34. A plunger, that is, a movable iron core 36 is mounted so as to be reciprocally movable in the axial direction. A rubber on-off valve 37 is attached to the tip of the movable iron core 36, and this on-off valve 37 comes into contact with a first valve seat 38 formed on the pilot block 19. An opening of an air supply passage 39 formed in the main valve block 15 and the pilot block 19 is formed in the valve seat 38 so as to communicate with the air supply port 21, and this opening is opened and closed by an on-off valve 37. Is done. A compression coil spring 40 for applying a spring force to the open / close valve 37 toward the valve seat 38 is attached to the movable iron core 36. Accordingly, when the coil 33 is energized, the movable iron core 36 moves toward the fixed iron core 35 against the spring force, and the opening of the air supply passage 39 is opened. The opening is closed.
[0020]
On the opposite side of the valve seat 38, a second valve seat 41 is formed in a direction opposite to the valve seat 38. The valve seat 41 has an opening of an exhaust passage 42 communicating with the outside of the pilot block 19. Is provided. A cylindrical valve holder 43 is attached to the pilot block 19 so as to cover the valve seat 41. A flapper valve 44 is incorporated in the valve holder 43 so as to be openable and closable. Open and close the opening of. A plurality of interlocking pins 45 are arranged between the flapper valve 44 and the movable iron core 36, and the flapper valve 44 is opened and closed by the movable iron core 36 via the interlocking pin 45.
[0021]
A through hole 46 is formed in the valve holder 43, and as shown in FIGS. 1 and 2, when the coil 33 is de-energized, the movable iron core 36 is pressed toward the valve seat 38 by a spring force. The valve 37 contacts the valve seat 38, and the flapper valve 44 is separated from the valve seat 41. As a result, the pneumatic chamber 29 is communicated with the outside via the exhaust passage 42, the air in the pneumatic chamber 29 is discharged to the outside, and the main valve shaft 17 is moved by the air pressure supplied into the pneumatic chamber 28 as shown in FIG. Is the first position as shown in FIG.
[0022]
On the other hand, when the coil 33 is energized, the on-off valve 37 moves away from the valve seat 38 and the flapper valve 44 is applied with a spring force toward the valve seat 41 by a coil spring 47 incorporated in the valve holder 43. Therefore, the compressed air supplied from the air supply port 21 through the air supply passage 39 enters the air pressure chamber 29 as an output portion through an output passage formed by a gap between the interlocking pin 45 and a hole through which the interlocking pin 45 passes. Inflow. Although the compressed air supplied to both air pressure chambers 28 and 29 has the same pressure, the pressure receiving area of the piston 27 is set to be larger than the pressure receiving area of the piston 26, so that the flapper valve 44 is closed and When the communication is closed and the compressed air is supplied into the air pressure chamber 29, the main valve shaft 17 is driven to the left stroke end position in FIG. 1, that is, the second position. As described above, the on-off valve 37 and the flapper valve 44 constitute a pilot valve that switches the output passage communicating with the pneumatic chamber 29 to the air supply passage 39 and the exhaust passage 42 to communicate therewith.
[0023]
On the other hand, the pilot block 19 is provided with a manual button 48 for moving the movable iron core 36 by manual operation to separate the on-off valve 37 from the valve seat 38. Can be activated.
[0024]
A mounting hole 51 is formed in the pilot block 19 at a predetermined depth from a connection end face with the main valve block 15, and a filter 52 is mounted in the mounting hole 51 across the exhaust passage 42. The filter 52 is formed of cloth, porous resin, or the like, and has a large number of pores. The filter 52 allows air from inside the pneumatic chamber 29 to be discharged to the outside, and discharges air from the pneumatic chamber 29 to the outside. When this is done, the exhaust noise is muted. In addition, foreign substances are prevented from entering the exhaust passage 42 from outside.
[0025]
FIG. 3 is a sectional view showing a solenoid valve according to another embodiment of the present invention, in which the manifold block 10 shown in FIG. 1 is omitted. In FIG. 3, members common to those shown in FIGS. 1 and 2 are denoted by the same reference numerals.
[0026]
The solenoid valve 11 shown in FIG. 3 has a main block 15 similar to that shown in FIG. 1, and a pilot block 19 provided with a solenoid 32 as shown in FIG. Therefore, this solenoid valve is a double solenoid type two-position valve in which pistons 27 having the same outer diameter are provided at both ends of the main valve shaft 17, and one pilot valve is provided for one solenoid valve. And two filters 52 are provided in the exhaust passage 42. Even with this type of solenoid valve, foreign substances can be prevented from flowing into the respective exhaust passages 42.
[0027]
Although the solenoid valve 11 shown in FIG. 3 is a two-position valve, the main valve shaft 17 is set to a neutral position by a spring force, and the main valve shaft 17 is moved to the stroke end position by each pilot valve. By doing so, a three-position valve can be obtained.
[0028]
As shown in the figure, a pilot valve formed by an on-off valve 37 and a flapper valve 44 is a direct-acting type in which an output passage is switched between an air supply passage 39 and an exhaust passage 42 by a plunger of a solenoid portion 32, that is, a movable iron core 36. , Which can be used as a single unit as a 3-port solenoid valve. Also in that case, it is possible to prevent foreign matter from flowing into the exhaust passage 42.
[0029]
The present invention is not limited to the above embodiment, and can be variously modified without departing from the gist thereof. For example, FIG. 1 shows a manifold type solenoid valve in which a plurality of solenoid valves are mounted on the manifold block 10, but the solenoid valve 11 shown in FIG. 1 can be used alone.
[0030]
【The invention's effect】
According to the present invention, since a filter is provided in the exhaust passage that guides air exhausted from the pneumatic chamber for driving the main valve shaft by operating the pilot valve, dust or the like is externally introduced into the exhaust passage. Foreign matter is prevented from entering, and the pilot valve can be operated smoothly. In addition, a noise reduction effect can be obtained by the filter, and exhaust noise due to air flowing out of the exhaust passage can be reduced.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a solenoid valve according to an embodiment of the present invention.
FIG. 2 is an enlarged sectional view showing a part of FIG.
FIG. 3 is a cross-sectional view showing a solenoid valve according to another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Manifold block 11 Solenoid valve 12 Air supply passages 13 and 14 Exhaust passage 15 Main valve block 16 Housing hole 17 Main valve shaft 18 Cover block 19 Pilot block 20 Valve casing 21 Supply ports 22, 23 Exhaust ports 24, 25 Output ports 26 piston 27 piston 28 pneumatic chamber 29 pneumatic chamber 31 air supply passage 32 solenoid part 33 coil 34 bobbin 35 fixed iron core 36 movable iron core 37 opening and closing valve 38 valve seat 39 air supply passage 40 compression coil spring 41 valve seat 42 exhaust passage 43 valve holder 44 Flapper valve 45 Interlocking pin 46 Through hole 47 Coil spring 48 Manual button 51 Mounting hole 52 Filter

Claims (4)

A valve casing in which a housing hole communicating with the air supply port, the output port, and the exhaust port is formed,
A main valve shaft that is provided in the accommodation hole so as to be reciprocally movable in the axial direction, and switches the output port to the air supply port and the exhaust port to communicate with each other;
A solenoid unit provided with a movable iron core attached to the valve casing and reciprocating in an axial direction by energizing a coil;
A pilot valve that is attached to the valve casing in conjunction with the movable core and switches an output passage communicating with an air pressure chamber that houses the piston to an air supply passage and an exhaust passage that communicates with the air supply port; ,
An electromagnetic valve, comprising: a filter provided in the exhaust passage, which prevents dust from flowing into the exhaust passage, and reduces exhaust noise at the time of exhaust. 2. The solenoid valve according to claim 1, wherein pistons are provided at both ends of the main valve shaft, and two pilot valves respectively operated by the solenoids are provided corresponding to two pneumatic chambers accommodating the respective pistons. Characteristic solenoid valve. 3. The solenoid valve according to claim 2, wherein the main valve shaft moves to two or three positions. An air supply passage having an open end formed in a first valve seat, an exhaust passage having an open end formed in a second valve seat opposite to the first valve seat, and A valve casing formed with an output passage for guiding the air flowing out of the air passage to the output unit,
A solenoid provided with a movable iron core attached to the valve casing and reciprocating in the axial direction by energizing the coil;
An on-off valve provided on the movable core to open and close the first valve seat;
A flapper valve arranged in the valve casing to face the open / close valve, and driven by the movable iron core via an interlocking pin to open and close the second valve seat;
An electromagnetic valve, comprising: a filter provided in the exhaust passage, which prevents dust from flowing into the exhaust passage, and reduces exhaust noise at the time of exhaust.

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