JP5794947B2 - Directional control valve - Google Patents

Description

  The present invention relates to a directional control valve in which a poppet-shaped valve body is opened and closed in a direction perpendicular to a valve seat surface to control a gas flow direction.

  The direction control valve switches between a state in which air pressure is supplied to the pneumatic operating device and a state in which supply is stopped, and a state in which air pressure is supplied to the pneumatic operating device and air discharged from the pneumatic operating device is discharged to the outside. And is also referred to as an on-off valve or switching valve. This type of directional control valve has a valve housing in which a valve hole for movably accommodating a valve shaft is formed. The valve housing is formed with a plurality of openings, that is, ports, communicating with the valve holes, and the ports are opened / closed and switched by a valve body that protrudes radially outward from the valve shaft. A valve body of a directional control valve of a type in which the valve body contacts, opens or closes and switches a port by contacting a valve seat surface formed in a direction perpendicular to the valve shaft is a poppet type.

  In a directional control valve having a poppet type valve body, when the valve body is opened and closed, the valve shaft or the valve body is guided to the valve housing. When air flows from one port to another port, air flows through the flow path between the valve shaft and the valve hole. In the direction switching valve described in Patent Document 1, a valve shaft is movably supported by a valve housing and a plurality of grooves through which air flows are formed on the outer peripheral surface of the valve shaft. It moves in the axial direction in contact with the guide hole of the valve hole. In the direct acting solenoid valve described in Patent Document 2, a guide ring that slides in the valve hole is provided on the valve shaft, and a flow path is formed by a notch provided in the guide ring. The valve shaft has a through hole communicating with the discharge port. One end of the through hole communicates with one spring chamber, and the other end of the through hole communicates with the other spring chamber. The axial thrust is balanced so as not to be applied to the valve shaft in the axial direction. The directional control valve described in Patent Document 3 is a type in which the valve body is supported so as to move in the axial direction by bringing the valve body into contact with the valve hole. The valve shaft is guided by a plurality of protruding pieces that are provided on the outer peripheral portion of the valve body so as to protrude radially outward and contact the inner peripheral surface of the valve hole, and a flow path is formed between the protruding pieces. . As a valve shaft drive system, there are an electromagnetic operation type using a solenoid, that is, an electromagnet, a mechanical operation type using a cam or a link, a fluid operation type using a fluid pressure, and the like.

JP-A-61-96272 JP-A-8-4936 JP 2006-258183 A

  In the conventional directional control valve having a poppet-shaped valve body, as described above, a flow path through which air flows is formed between the valve shaft to which the valve body is attached and the valve hole, and the outer peripheral surface of the valve shaft A groove is formed in the valve shaft, and the valve shaft and the valve hole are in sliding contact with each other. Similarly, when the guide ring is fixed to the valve shaft and a notch for forming a flow path is provided in the guide ring, the guide ring slides in contact with the valve hole. Even when a protrusion piece is provided on the outer periphery of the valve body, the protrusion piece slides in surface contact with the valve hole.

  Thus, the valve shaft is mounted so as to be able to reciprocate in the valve hole of the valve housing in the axial direction. When the valve shaft is moved, the valve shaft is centered in a direction that tilts in the valve hole or moves in the radial direction. It is necessary not to slip. If the valve shaft is displaced in the valve hole when it moves, the valve body does not sufficiently contact the valve seat surface, so that only a part of the valve seat surface may contact and the sealing performance may not be ensured. Furthermore, when operating the valve body at high speed, it is necessary to reduce the sliding resistance of the valve shaft provided with the valve body. When guiding the valve shaft by bringing the valve shaft into surface contact with the valve hole of the valve housing or bringing the outer peripheral surface of the valve body into surface contact with the valve hole, in order to reduce the sliding resistance of the valve shaft, It is necessary to ensure a relatively large clearance from the processing accuracy of valve holes and valve shafts. However, if the clearance is increased, the valve shaft may be misaligned, so that the sealing performance between the valve seat surface and the valve body is inevitably lowered as described above.

  When the spring force for urging the valve shaft in the axial direction is increased, the pressing force by which the valve body is pressed against the valve seat surface, that is, the sealing force for the valve seat surface of the valve body can be increased. In the electromagnetic operation type using a solenoid as a drive source, not only can the high-speed response of the valve body be improved, but the solenoid current must be increased, and deterioration of the opening / closing performance due to a rise in coil temperature is inevitable. .

  On the other hand, in order to seal the flow of air by bringing the valve body into contact with the valve seat surface, it is necessary to secure a contact area between the valve body and the valve seat surface. When the valve seat has a circular shape corresponding to a valve body having a circular outer peripheral surface as in the past, in order to secure a flow path area between the outer peripheral surface of the valve body and the inner peripheral surface of the valve hole, Since it is necessary to increase the outer diameter, the valve assembly including the valve body and the valve shaft must be enlarged. In order to increase the flow rate by increasing the size of the valve body, it is necessary to increase the seat force, and the valve body cannot be opened and closed at high speed. Furthermore, if the valve shaft is guided by a protruding piece provided so as to protrude from the outer peripheral surface of the valve body as in Patent Document 3, the valve housing must be enlarged.

  An object of the present invention is to improve the opening / closing characteristics by preventing the center deviation of the valve shaft while increasing the flow path between the valve shaft and the valve hole without increasing the size of the directional control valve.

Directional control valves of the present invention, the feed supply port air is supplied, and an output port for the outflow of air from the supply port, communicated with the exhaust port for discharging air that is returned to the output port to the outside A valve housing having a valve housing hole having a port and a supply-side valve hole communicating with the output port; and a discharge housing provided in the valve housing hole for communicating the output port with the discharge port. A cylindrical guide member provided with a valve hole, a valve shaft that is reciprocally mounted in the valve housing hole in the axial direction, and a valve provided at an end of the guide member and provided on the valve shaft A valve seat on the discharge side that contacts the body and closes the valve hole on the discharge side, opens the valve hole on the discharge side away from the valve body, and protrudes radially inward toward the valve shaft together with the moth apart circumferentially Provided on the inner surface of the de member, the projection portion of the at least three guide members to form a communicating groove of the guide member therebetween, provided extending in the axial direction the protrusion of the guide member, support the valve shaft The guide member guides the valve shaft in the axial direction at the line contact portion of the guide member, and abuts the valve seat surface on the discharge side against the valve body. It is characterized by making it seal .

  In this directional control valve, the valve shaft provided with the valve element is supported by the line contact portion provided in the valve hole for communicating the ports, so that the sliding between the line contact portion and the valve shaft is possible. Dynamic resistance can be reduced. Accordingly, the occurrence of misalignment of the valve shaft can be prevented, so that the entire contact surface of the valve body can be brought into contact with the valve seat surface, and the sealing performance of the valve seat surface can be enhanced. Further, since the sliding resistance applied to the valve shaft when the valve shaft moves can be reduced, the thrust for driving the valve shaft can be reduced.

  Since this thrust can be reduced, the spring member for applying the thrust to the valve shaft can be reduced in size, the solenoid can be reduced in size, and the entire direction control valve can be reduced in size. When the line contact portion is provided in the valve hole, a communication passage having a large cross-sectional area can be formed in the valve hole without increasing the valve hole, and thus the direction control valve can be reduced in size.

It is a partially notched front view of the direction control valve which is one embodiment of this invention. It is sectional drawing which expands and shows a part of FIG. It is a perspective view which shows the longitudinal cross-section of a valve housing. (A) is the perspective view which shows the guide member shown by FIG. 2, (B) is the perspective view seen from the opposite side of (A). (A) is the left view of FIG. 4 (A), (B) is the 5B-5B sectional view taken on the line in (A). FIG. 6 is an enlarged sectional view taken along line 6-6 in FIG. FIG. 7 is an enlarged cross-sectional view taken along line 7-7 in FIG. FIG. 3 is an exploded front view of the valve shaft shown in FIG. 2.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The directional control valve shown in FIGS. 1 and 2 is a 5-port solenoid valve in which a main valve assembly operates in two positions, and has a substantially rectangular parallelepiped block-shaped valve housing 10. A through hole, that is, a valve accommodating hole 11 is formed in the valve housing 10 so as to extend in the longitudinal direction, and a supply port 12 connected to an air pressure supply source (not shown) is provided at the center of the valve housing 10 in the longitudinal direction. A valve housing 10 is formed in communication with the valve housing hole 11. An output port 13 a is formed in the valve housing 10 so as to communicate with the valve accommodating hole 11 while being shifted from the supply port 12 to one side in the longitudinal direction. A pneumatic operating device such as a pneumatic cylinder is connected to the output port 13a, and the output port 13a communicating with the supply port 12 allows air to flow out to the pneumatic operating device. A discharge port 14a is formed in the valve housing 10 so as to be shifted to one side in the longitudinal direction with respect to the output port 13a. The discharge port 14a is returned to the output port 13a from the pneumatic operating device. Exhaust air to the outside.

  An output port 13 b is formed in the valve housing 10 so as to communicate with the valve accommodating hole 11 while being shifted from the supply port 12 to the other side in the longitudinal direction. A pneumatic operating device such as a pneumatic cylinder is connected to the output port 13b, and the output port 13b communicating with the supply port 12 allows air to flow out to the pneumatic operating device. A discharge port 14b is formed in the valve housing 10 so as to be shifted to the other side in the longitudinal direction with respect to the output port 13b. The discharge port 14b is returned from the pneumatic operating device to the output port 13b. Exhaust air to the outside.

  The output port 13a described above is a first output port, the output port 13b is a second output port, the discharge port 14a is a first discharge port, and the discharge port 14b is a second output port. It has become a discharge port. Both the discharge ports 14a and 14b communicate with each other through a communication path 14c provided at a position shifted from the supply port 12 and the output ports 13a and 13b. The communication path 14c is indicated by a two-dot chain line in FIG.

  Each of the ports described above is formed to open on the bottom side of the valve housing 10 in FIG. The valve housing 10 is attached to a mounting member such as a manifold block (not shown), and the mounting member is formed with a flow path communicating with each port. For example, when a plurality of directional control valves are mounted on a manifold block as a mounting member, the supply port 12 of each directional control valve is communicated with a common supply flow path formed in the manifold block. The two output ports 13a and 13b of the directional control valve are connected to a pneumatically operated device by a joint attached to the manifold block. The two discharge ports 14a and 14b of the direction control valve are communicated with each other through a communication passage 14c and are also communicated with an exhaust passage formed in a manifold block.

  An output port 15a that communicates with the output port 13a via the valve accommodating hole 11 is formed in the upper surface of the valve housing 10 in FIG. 2, and an output port 15b that communicates with the output port 13b via the valve accommodating hole 11 is formed. Is formed in the upper surface of the valve housing 10. The respective output ports 15 a and 15 b are used when a pneumatic actuator is directly connected to the valve housing 10. At that time, the other output ports 13a and 13b are closed without being communicated with the pneumatic actuator, and the output port 15a becomes the first output port and the output port 15b becomes the second output port. On the other hand, when the output ports 13a and 13b are connected to the pneumatic actuator via the mounting member, the output ports 15a and 15b are closed by a cover member (not shown).

  In the following description, when the output ports 13a and 13b communicate with other ports, the output ports 15a and 15b communicate with each other. A duplicate description of communication is omitted.

  A main valve assembly 20 is mounted in the valve housing hole 11 so as to be capable of reciprocating in the axial direction. The main valve assembly 20 includes a valve shaft 21 and two integral valve bodies 22 and 23 made of rubber. The outer diameter of the integral valve bodies 22 and 23 is larger than that of the valve shaft 21. Large diameter. A cylindrical guide member 24a is arranged on one end side of the valve housing 10, and a cylindrical guide member 24b is also arranged on the other end side. The guide member 24 a is a first guide member, and is attached to a cylindrical adjustment screw member 25 a that is fixed to one end of the valve housing hole 11. The guide member 24 b is a second guide member, and is attached to a cylindrical adjustment screw member 25 b that is fixed to the other end of the valve housing hole 11. The two guide members 24a and 24b have the same shape, and similarly, the two adjustment screw members 25a and 25b have the same shape, and are opposite to each other in the valve housing 10. Installed. The axial movement range of the main valve assembly 20 can be adjusted by adjusting the axial positions of both the adjusting screw members 25a and 25b.

  As shown in FIG. 2, an end block 16 is abutted against one end of the valve housing 10, and the end block 16 is fixed to the valve housing 10 by a screw member (not shown). A solenoid 18 is abutted against the flange 17 provided at the other end of the valve housing 10, and the solenoid 18 is fixed to the valve housing 10 by a screw member (not shown). As shown in FIG. 1, the case body 26 of the solenoid 18 incorporates a U-shaped fixed iron core 27 in which two rod-shaped portions 27a and an arc-shaped portion 27b connecting them are integrated. A bobbin 29 around which a solenoid coil 28 is wound is attached to the rod-like portion 27a.

  In order to supply a drive current to the solenoid coil 28, a connector 30 is detachably attached to the case body 26 of the solenoid 18, as shown in FIG. A movable iron core 31 is disposed on the front surface of the rod-shaped portion 27 a, and when a drive current is supplied to the solenoid coil 28, the movable iron core 31 is attracted toward the fixed iron core 27 by a magnetic force. Thus, the illustrated direction control valve is of an electromagnetic operation type.

  As shown in FIG. 2, the movable iron core 31 is floated by a leaf spring 32 and attached to the case body 26. The leaf spring 32 has a central portion 32a fixed to the movable iron core 31, and leg portions 32b provided at both ends thereof. The leaf spring 32 is formed by bending a belt-like elastic plate, and the leg portion 32b is formed in the case body 26. It is fixed in the recessed part formed in. A claw portion (not shown) is provided in the central portion 32a, and the movable iron core 31 is attached to the leaf spring 32 by the claw portion, and the movable iron core 31 is floated by the leaf spring 32 so as to be movable in the axial direction of the valve shaft 21. Is supported.

  An operation button 33 is attached to the end block 16 so as to be reciprocally movable in the axial direction so as to be coaxial with the valve shaft 21. Drive pieces 34 and 35 are attached to both ends of the valve shaft 21, and between the drive piece 34 on one end side of the valve shaft 21 and the operation button 33, the valve shaft 21 is moved to the right in FIG. 2. A compression coil spring 36 is mounted as a spring member for urging the thrust to go. Due to the spring force of the compression coil spring 36, the end face of the drive piece 35 abuts on the movable iron core 31, and the plate spring 32 is formed with a through hole 32c into which the drive piece 35 enters. In order to urge the valve shaft 21 to thrust leftward against the spring force of the compression coil spring 36, a compression coil spring 37 is arranged as a spring member in the case body 26, and the compression coil spring 37. Is accommodated in a recess 38 formed in the movable iron core 31.

  The spring force urged toward the left direction in FIG. 2 by the compression coil spring 37 in FIG. 2 is stronger than the spring force urged toward the right direction with respect to the valve shaft 21 by the compression coil spring 36. It has become. When a drive signal is not applied to the solenoid coil 28, the valve shaft 21 is located at the first position in the left direction. On the other hand, when a drive current is supplied to the solenoid coil 28, the movable iron core 31 is driven toward the fixed iron core 27, and the valve shaft 21 is driven to the second position in the right direction by the spring force of the compression coil spring 36. The When the operation button 33 is pushed in, the operation button 33 comes into contact with the drive piece 34 and the valve shaft 21 moves to the second position without energizing the solenoid coil 28.

  As shown in FIG. 2, the portion between the supply port 12 and the output port 13 a in the valve accommodating hole 11, that is, the portion between the first supply side ports, communicates with the first valve on the supply side. A hole 41a is formed. A portion between the supply port 12 and the output port 13b, that is, a portion between the second supply side ports, is formed with a second valve hole 41b on the supply side for communicating these. A supply-side first valve seat surface 42a is formed at the end of the valve hole 41a on the output port 13a side, and a supply-side second valve seat surface 42b is formed at the end of the valve hole 41b on the output port 13b side. Is formed. The valve holes 41a and 41b and the valve seat surfaces 42a and 42b are formed in the valve housing 10, and both valve seat surfaces 42a and 42b face in opposite directions.

  As shown in FIGS. 4 and 5, the guide member 24a is formed of a cylindrical member, and has a first valve hole on the discharge side for communicating the output port 13a and the discharge port 14a on one end side. 43a is formed. The valve hole 43a is provided in a first discharge side inter-port portion between the output port 13a and the discharge port 14a. A discharge-side first valve seat surface 44a is formed on one end surface of the guide member 24a, and an end portion of the valve hole 43a on the output port 13a side is opened in the valve seat surface 44a. When the guide member 24a is incorporated in the valve housing 10, the valve hole 43a formed in the guide member 24a is a first valve on the discharge side coaxial with the first valve hole 41a on the supply side formed in the valve housing 10. It becomes a hole. Further, the valve seat surface 44a serves as a first valve seat surface on the discharge side facing the first valve seat surface 42a on the supply side.

  An annular groove 46a in which the seal member 45a is mounted is formed on the outer peripheral surface on the one end portion side of the guide member 24a, and the discharge port 14a and the output port 13a are sealed by the seal member 45a. On the other end side of the guide member 24a, a plurality of first through holes 47a are formed to communicate the output port 13a and the discharge port 14a via the valve hole 43a.

  The guide member 24b has the same shape as the guide member 24a, and is provided in the valve housing 10 in the opposite direction to the guide member 24a. The valve hole 43b on the one end portion side of the guide member 24b is provided in a portion between the second discharge side ports between the output port 13b and the discharge port 14b, and serves as a second valve hole on the discharge side. . The output port 13b and the discharge port 14b communicate with each other through the valve hole 43b. When the guide member 24b is incorporated in the valve housing 10, the valve hole 43b formed in the guide member 24b is a second valve on the discharge side that is coaxial with the second valve hole 41b on the supply side formed in the valve housing 10. It becomes a hole. Further, the valve seat surface 44b becomes a second valve seat surface on the discharge side facing the second valve seat surface 42b on the supply side.

  An annular groove 46b in which the seal member 45b is mounted is formed on the outer peripheral surface on the one end side of the guide member 24b, and the discharge port 14b and the output port 13b are sealed by the seal member 45b. A plurality of through holes 47b formed on the other end side of the guide member 24b are second through holes that allow the output port 13b and the discharge port 14b to communicate with each other through the valve hole 43b.

In the valve accommodating hole 11, the valve holes 41a and 41b communicating with the supply port 12 and the output ports 13a and 13b have the smallest inner diameter. Portions between the output ports 13a and 13b and the discharge ports 14a and 14b where the guide members 24a and 24b are fitted have larger inner diameters than the valve holes 41a and 41b. The portions where the adjustment screw members 25a and 25b are screw-coupled at both ends of the valve accommodating hole 11 have a larger inner diameter and become a maximum diameter portion.

  The integrated valve body 22 includes a first valve body 51a on the supply side that abuts on the first valve seat surface 42a on the supply side, and a first on the discharge side that abuts on the first valve seat surface 44a on the discharge side. And has a valve body 52a. Similarly, the integrated valve body 23 includes a second valve body 51b on the supply side that contacts the second valve seat surface 42b on the supply side and a discharge side that contacts the second valve seat surface 44b on the discharge side. And a second valve body 52b, which are integrated. As described above, by integrating the two valve bodies, the mounting strength of the integrated valve bodies 22 and 23 with respect to the valve shaft 21 can be increased, and the valve body can be attached to the valve shaft 21 with fewer steps. Can do.

  6 is an enlarged cross-sectional view taken along line 6-6 in FIG. 2, and shows the cross-sectional shapes of the valve hole 41a and the valve shaft 21. FIG. The maximum inner diameter of the valve hole 41a is set smaller than the outer diameter of the valve body 51a. When the valve body 51a comes into contact with the valve seat surface 42a, the valve hole 41a is closed by the valve body 51a. Four protrusions 53 protrude radially inwardly from the inner peripheral surface of the valve hole 41a and are provided in a mountain shape. Each protrusion 53 is spaced apart at equal intervals in the circumferential direction and extends in the axial direction. . The protruding tip of the protrusion 53 has an arc shape, and a line contact portion 54 that makes line contact with the outer peripheral surface of the valve shaft 21 is provided at the protruding tip of the arc shape. The line contact portion 54 extends in the axial direction from the valve seat surface 42a over the entire length of the valve hole 41a. However, the line contact portion 54 may be partially provided without being provided over the entire length of the valve hole 41a. A portion other than the line contact portion 54 on the inner peripheral surfaces of the valve shaft 21 and the valve hole 41 a, that is, a space between the protrusions 53 in the circumferential direction is a communication groove 55. A communication flow path that connects the supply port 12 and the output port 13a is formed by the four communication grooves 55 formed in the valve hole 41a.

  The cross-sectional shape of the valve hole 41b is the same as that of the valve hole 41a. Four line contact portions 54 are provided on the inner peripheral surface of the valve hole 41b, and a communication groove 55 is formed between the protrusions 53. Yes.

  7 is an enlarged cross-sectional view taken along line 7-7 in FIG. 2, and shows the cross-sectional shapes of the valve hole 43a and the valve shaft 21. FIG. The maximum inner diameter of the valve hole 43a provided in the guide member 24a is set smaller than the outer diameter of the valve body 52a. When the valve body 52a contacts the valve seat surface 44a, the valve hole 43a is closed by the valve body 52a. It is done. On the inner peripheral surface of the valve hole 43a, like the valve holes 41a and 41b, four protrusions 53 protrude inward in the radial direction, and each protrusion 53 has a circumferential shape and the like. They are spaced apart. A line contact portion 54 is provided at the arc-shaped protruding tip of the protrusion 53 over the entire length of the valve hole 43a from the valve seat surface 44a. However, the line contact portion 54 may be partially provided without being provided over the entire length of the valve hole 43a. Of the inner peripheral surfaces of the valve shaft 21 and the valve hole 43a, the portion other than the line contact portion 54, that is, the space between the protrusions 53 in the circumferential direction is provided with a communication groove 55 for communicating the output port 13a and the discharge port 14a It has become.

  The cross-sectional shape of the valve hole 43b provided in the guide member 24b is the same as that of the valve hole 43a, and four line contact portions 54 are provided on the inner peripheral surface of the valve hole 43b.

  Thus, since the valve shaft 21 is in line contact with any of the plurality of line contact portions 54 and reciprocates in the axial direction in the portion that penetrates the valve hole, the line contact portion 54 and the valve shaft 21 Even if this clearance is set sufficiently small, the sliding resistance of the valve shaft 21 can be reduced. As a result, the valve shaft 21 is supported in a floating state, the valve shaft 21 can be driven at high speed, high-speed response can be improved, and misalignment of the valve shaft 21 can be reliably prevented. The sealing performance between the valve body and the valve seat surface can be ensured over a long period of time. In addition, the cross-sectional shape of each valve hole has a cross shape, and a portion other than the line contact portion 54 can be used as the communication groove 55. Therefore, the flow of the communication flow path between the ports formed by the communication groove 55 The area can be sufficiently secured without increasing the inner diameter of the valve hole.

  In the illustrated directional control valve, four line contact portions 54 are provided in each valve hole. However, when the three line contact portions 54 are provided in the circumferential direction, the three line contact portions 54 are provided. It becomes a form. In this embodiment, the flow area of the communication channel formed by the communication groove 55 can be made larger than when four line contact portions 54 are provided. However, five or more line contact portions 54 may be provided.

  In this directional control valve, although the circumferential positions of the line contact portions 54 of the two valve holes 41a and 41b provided integrally with the valve housing 10 are the same, both valve holes 41a and 41b are aligned. The positions of the line contact portions 54 in the circumferential direction may be shifted from each other. By shifting in this way, the valve shaft 21 can be supported at eight portions in the circumferential direction in the two valve holes 41a and 41b as a whole. Similarly, by adjusting the circumferential positions of the two guide members 24a and 24b, the valve shaft 21 can be supported by a larger number of portions.

  As shown in FIG. 2, in the five-port directional control valve, the air pressure supplied to the supply port 12 acts in the opposite direction on the two valve bodies 51a and 51b that are in the opposite directions. The thrust in the axial direction is not applied to the valve shaft 21 by the air pressure of 12, and the thrust is balanced. Further, since the two discharge ports 14a and 14b are connected to each other by a communication passage 14c provided in the valve housing 10, the discharge air pressures flowing into the respective discharge ports 14a and 14b are opposite to each other. It acts on the valve bodies 52a and 52b in the opposite direction. Thereby, thrust is not applied to the valve shaft 21 in the axial direction by the discharged air pressure, and the thrust is balanced. Thus, the directional control valve shown in the figure is a balanced type without forming a through hole in the valve shaft 21, and at a high speed without increasing the size of the compression coil springs 36 and 37 and the solenoid 18. The main valve assembly 20 can be driven.

  In the directional control valve described above, the line contact portions 54 are respectively connected to the valve holes 41 a and 41 b formed in the valve housing 10 and the valve holes 43 a and 43 b formed in the guide members 24 a and 24 b incorporated in the valve housing 10. Is provided. As a result, the valve shaft 21 is guided and reciprocated by any of the line contact portions 54 in all the valve holes. Since the line contact part 54 extends in the axial direction and is formed in the valve hole, the line contact part 54 is provided in at least one of the valve holes without providing the line contact part 54 in all the valve holes. In addition, the line contact portion 54 can prevent the valve shaft 21 from being misaligned.

  For example, the line contact part 54 is provided only in the valve holes 41a and 41b formed in the valve housing 10, and the valve holes 43a and 43b are provided without providing the line contact part 54 in the valve holes 43a and 43b of the guide members 24a and 24b. When the cross section is circular, the directional control valve has a configuration in which the line contact portion 54 is provided only in the valve housing 10. In contrast, when the valve holes 41a and 41b are circular in cross section and the line contact portions 54 are provided in the valve holes 43a and 43b of the guide members 24a and 24b, the line contact portions 54 are provided only in the guide members 24a and 24b. This is a directional control valve. In these directional control valves, a line contact portion 54 is provided in two valve holes. Further, the valve hole provided with the line contact portion 54 may be provided at three or one of the four valve holes. In any form, the valve shaft 21 is provided by the line contact portion 54. The occurrence of misalignment is prevented.

As shown in FIG. 8, the valve shaft 21 includes a connecting shaft 56 that passes through the valve holes 41a and 41b on the supply side, and first and second valved shafts 56a connected to both ends of the connecting shaft 56, 56b, and the two valve shafts 56a and 56b have the same shape. Small-diameter coupling portions 57a and 57b having a smaller diameter than the central portion are provided at both ends of the coupling shaft 56, and a fitting hole 58a into which the small-diameter coupling portion 57a is fitted is one end on the first valved shaft 56a. A fitting hole 58b is formed at one end of the second valved shaft 56b. The fitting hole 58b is fitted into the second valved shaft 56b. Small-diameter coupling portions 59a and 59b to which the drive pieces 34 and 35 are attached are provided at the other end portions of the valve-equipped shafts 56a and 56b.

  Large-diameter flanges 61a and 61b are provided at one end portions, that is, fitting end portions of the valve-equipped shafts 56a and 56b. The integrated valve body 22 in which the two valve bodies 51a and 52a are integrated is provided so as to cover the flange 61a, and the integrated valve body 23 in which the two valve bodies 51b and 52b are integrated covers the flange 61b. It is provided as such. By molding the integral valve bodies 22 and 23 on the valve-equipped shafts 56a and 56b with a rubber material, the two valve bodies are molded integrally.

  In order to assemble the main valve assembly 20 to the valve housing 10, one shaft with a valve, for example, a shaft 56 a with a valve, is connected to the connecting shaft 56, and is connected to the valve housing hole 11 from the left side in FIG. insert. At this time, since the inner diameter of the valve housing hole 11 on the left side of the valve hole 41a is larger than the outer diameter of the integrated valve body 22, it can be easily inserted. Next, the adjusting screw member 25a to which the guide member 24a is attached is inserted into the outside of the valved shaft 56a and screwed to the valve housing 10. Further, the other valved shaft 56b is inserted into the valve accommodating hole 11, the valved shaft 56b is connected to the connecting shaft 56, and the adjusting screw member 25b to which the guide member 24b is attached is inserted outside the valved shaft 56b. And screwed to the valve housing 10. The movement range of the main valve assembly 20 in the axial direction is adjusted by the axial positions of both the adjusting screw members 25a and 25b.

  When the rod of a pneumatic cylinder as a pneumatic actuator is reciprocated by the directional control valve described above, for example, the output port 13b is connected to the forward pneumatic chamber of the pneumatic cylinder and the output port 13a is connected to the backward pneumatic chamber. When the drive current is not supplied to the solenoid coil 28, the valve shaft 21 is driven to the first position on the left side in FIG. 2 by the spring force of the compression coil spring 37. At this time, the supply port 12 communicates with the output port 13a, and the discharge port 14b communicates with the output port 13b. As a result, compressed air from the outside is supplied to the retreating pneumatic chamber via the supply port 12 and the output port 13a, and the rod reaches the retreat limit position. At the same time, the compressed air in the forward pneumatic chamber is discharged from the output port 13b to the discharge port 14b.

  When a drive current is supplied to the solenoid coil 28, the valve shaft 21 is driven to the second position. At this time, the supply port 12 communicates with the output port 13b, and the discharge port 14a communicates with the output port 13a. Thereby, compressed air from the outside is supplied to the forward pneumatic chamber via the supply port 12 and the output port 13b, and the rod is driven to the forward limit position. At the same time, the compressed air in the retreating pneumatic chamber is discharged from the output port 13a to the discharge port 14a.

  The illustrated directional control valve is a 5-port type having a pair of output ports 13a and 15a and a discharge port 14a that share the supply port 12 and a pair of output ports 13b and 15b and a discharge port 14b. On the other hand, the directional control valve in which the supply port 12, the paired output port 13a or 13b, and the discharge port 14a or 14b are provided is a three-port type. Further, the directional control valve that opens and closes the supply port and the output port and does not have a discharge port is a two-port type. In any of these forms, by providing the line contact portion 54 in the valve hole, the valve shaft 21 is supported in a floating state, and without increasing the sliding resistance of the valve shaft 21, The high-speed response can be improved and the flow passage area of the communication path can be increased.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the illustrated directional control valve, the two discharge ports 14a and 14b are communicated with each other through the communication path 14c to balance the discharge air pressure. However, the communication path 14c may not be provided. good.

DESCRIPTION OF SYMBOLS 10 Valve housing 11 Valve accommodation hole 12 Supply port 13a, 13b Output port 14a, 14b Discharge port 14c Communication path 15a, 15b Output port 20 Main valve assembly 21 Valve shaft 24a, 24b Guide member 27 Fixed iron core 28 Solenoid coil 31 Movable iron core 36, 37 Compression coil spring 41a Valve hole (first valve hole on the supply side)
41b Valve hole (second valve hole on the supply side)
42a Valve seat surface (first valve seat surface on the supply side)
42b Valve seat surface (second valve seat surface on the supply side)
43a Valve hole (first valve hole on the discharge side)
43b Valve hole (second valve hole on the discharge side)
44a Valve seat surface (first valve seat surface on the discharge side)
44b Valve seat surface (second valve seat surface on the discharge side)
51a Valve body (first valve body on the supply side)
51b Valve body (second valve body on the supply side)
52a Valve body (first valve body on the discharge side)
52b Valve body (second valve body on the discharge side)
53 Projection 54 Line Contact 55 Communication Groove

Claims (9)

A supply port through which air is supplied, and an output port for the outflow of air from the supply port, communicating said supply port and said output port communicated with the discharge port for discharging the air that is returned to the output port to the outside A valve housing formed with a valve housing hole having a valve hole on the supply side;
A cylindrical guide member provided in the valve housing hole and provided with a discharge-side valve hole for communicating the output port and the discharge port ;
A valve shaft that is reciprocally mounted in the valve housing hole in the axial direction ;
A discharge-side valve is provided at an end of the guide member, abuts on a valve body provided on the valve shaft, closes the discharge-side valve hole, and separates from the valve body and opens the discharge-side valve hole. A valve seat surface;
With projecting radially inwardly toward the valve shaft, apart circumferentially provided on an inner surface of the guide member, the protruding portion of the at least three guide members forming the communicating groove of the guide member therebetween When,
A protruding portion of the guide member that extends in the axial direction and has a line contact portion of the guide member that supports the valve shaft;
The guide member guides the valve shaft in the axial direction at a line contact portion of the guide member, and seals the valve body by contacting the valve seat surface on the discharge side. . The direction control valve according to claim 1,
Forming a valve seat surface on the supply side at the end of the valve hole on the supply side;
Projecting portions of at least three valve housings projecting inward in the radial direction toward the valve shaft and forming communication grooves of the valve housing between them in a circumferential direction are provided on the inner surface of the valve hole on the supply side Provided in
A line contact portion of the valve housing that extends in the axial direction and supports the valve shaft is provided on the protrusion of the valve housing,
A directional control valve characterized in that the valve shaft is guided by a line contact portion of the valve housing and a line contact portion of the guide member. The direction control valve according to claim 2,
The direction control valve according to claim 1, wherein a portion into which the guide member is fitted is larger than an inner diameter of the valve hole on the supply side. The direction control valve according to claim 1,
There are two output ports, a first output port and a second output port, and the discharge port includes a first discharge port that communicates with the first output port, and a second output port. Two with a second discharge port in communication,
The guide member includes a cylindrical first guide member provided with a first valve hole on a discharge side for communicating the first output port with the first discharge port, and the second output port. And a cylindrical second guide member provided with a second valve hole on the discharge side for communicating with the second discharge port,
The supply-side valve hole includes a supply-side first valve hole that communicates the supply port and the first output port, and a supply-side first hole that communicates the supply port and the second output port. A directional control valve having two valve holes. The direction control valve according to claim 4,
Projecting portions of at least three guide members projecting radially inward toward the valve shaft and forming communication grooves of the guide members therebetween are formed on the inner peripheral surfaces of the first and second guide members. Set apart in the circumferential direction,
A directional control valve characterized in that a linear contact portion of a guide member that supports the valve shaft is provided to extend in the axial direction at a protrusion of the guide member. The direction control valve according to claim 4,
The at least three valve housing protrusions projecting radially inward toward the valve shaft and spaced apart in the circumferential direction to form a communication groove of the valve housing therebetween. Provided on the inner surface of the hole,
A directional control valve characterized in that a line contact portion of a valve housing that extends in the axial direction and supports the valve shaft is provided on a protrusion of the valve housing. The direction control valve according to claim 4,
The valve shaft is formed by a connecting shaft and a valved shaft connected to both ends of the connecting shaft. The direction control valve according to claim 4,
An directional control valve characterized in that an adjusting screw member for attaching the guide member is screwed to both ends of the valve housing hole, and a moving range of the valve shaft is adjusted by the adjusting screw member. The direction control valve according to claim 4,
The valve housing is provided with a communication passage communicating with the first discharge port and the second discharge port, shifted from the supply port and the first and second output ports. Directional control valve.

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