JP2005325881A - Method for switching flow passage by slide valve and change-over valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enlarge the opening diameter of a port 420 while effectively preventing damage of seal means. <P>SOLUTION: As the seal means, first and second seal rings 2121, 2122 separated from each other in the axial direction are used. Depending on whether the two seal rings 2121, 2122 seal the upper side or lower side of the port 420 of a slide valve element 400, an air inlet 102 side and an air outlet 104 side are communicated/blocked, At the time of such switching action, each of the seal rings 2121, 2122 is moved between a seal position opposing to the port 420 and a non-seal position separated from the port 420. During this movement, the seal rings 2121, 2122 move across only one of both edges of the port 420 and never move across the both edges. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for switching a flow path that passes through a port in accordance with a relative movement of a slide valve body, and more particularly to a technique that is effective in expanding the opening diameter of a port.

  Generally, a slide valve includes an outer member having a support hole along an axis, and a slide valve body that fits in the support hole of the outer member and moves relative to the outer member in the direction of the axis. According to the relative movement of the body, it has the function of switching the flow path through the port. The port is provided on either the slide valve body or the outer member, and either of them has a sealing means for sealing between the slide valve body and the outer member. The flow path changes depending on whether this sealing means seals one side of the port or the other side when viewed in the axial direction.

In Patent Document 1 showing an air governor for an air compressor of a vehicle, a port is provided on the side of a relatively moving slide valve body, and a sealing means is provided on the side of a piston which is an outer member. Also, in Patent Document 2 in which the slide valve body is a plate-like slide type valve, contrary to Patent Document 1, a port is provided on the side of the main body, which is an outer member, and a sealing means is provided on the side of the plate-like slide valve body. It is arranged.
US Pat. No. 6,038,856 JP 2000-337532 A

  In these Patent Documents 1 and 2, the arrangement of the port / seal means with respect to the slide valve body / outer member is reversed, but the switching of the flow path is common. That is, when the flow path is switched, the sealing means moves so as to cross the port. Here, “crossing” means crossing so as to pass through both one edge defining the port and the other edge on the radially opposite side of the port. It will be readily appreciated that the sealing means (rubber seal ring) is subject to wear and damage since the sealing means crosses the port. Therefore, in order to prevent damage to the sealing means, in Patent Document 1, the opening diameter of the port is made as small as possible, and in Patent Document 2, an additional mechanism that moves up and down when the slide valve body moves is provided. .

  In the technique of Patent Document 1, since the flow area of the port portion is small, the amount of air passing through the port is not sufficient, and it is difficult to directly operate the air device with the air. Therefore, when operating an air device, a relay valve using air passing through the port as a control pressure must be used. On the other hand, in the technique of Patent Document 2, since the opening diameter of the port can be increased, the air device can be directly operated. However, there is a problem that an extra additional mechanism is required.

Therefore, an object of the present invention is to provide a technique capable of expanding the opening diameter of the port while effectively preventing damage to the sealing means.
Another object of the present invention is to provide a technique capable of expanding the opening diameter of a port without using an extra additional mechanism.
Other objects of the present invention will become clear from the following description.

  In the present invention, the sealing means is prevented from crossing the port by devising the structure of the sealing means. Here, as described above, the term “crossing” means to cross both the one edge defining the port and the other edge on the radially opposite side of the port, and “do not cross”. Means that only one of the edges of the port crosses but does not cross both edges.

  As the sealing means, there are first and second seal rings which are separated from each other in the axial direction, and the first and second seal rings face the port and do not perform a sealing action, and the axial direction from the port. It moves to and from the sealing position where the sealing action is performed.

  Taking the air governor as an example, the opening diameter of the port so far has been 0.6 to 0.7 mm, for example, while the opening diameter of the air governor to which the present invention is applied is, for example, 3.5 mm. The air device can be operated directly by the air passing through. Note that the flow path passing through the port in the air governor includes an inlet flow path that communicates from the port to the air inlet, an exhaust flow path that communicates from the port to the exhaust port, and an outlet flow path that communicates from the port to the air outlet. The air governor, which is a switching valve, acts to switch between a state in which the inlet channel and the outlet channel communicate with each other and a state in which the outlet channel and the exhaust channel communicate with each other.

  In a preferred embodiment, the opening diameter of the port is small compared to the axial distance between the first and second seal rings. Then, different contact states can be selectively obtained. Furthermore, for example, a situation in which the three of the inlet channel, the exhaust channel and the outlet channel communicate with each other (if such a situation occurs, the inlet pressure leaks to the exhaust side and a predetermined output pressure can be obtained. Can not effectively occur).

  In addition, the port (or each port) preferably includes a hole portion such as a through hole orthogonal to the axis and a tapered portion surrounding the hole portion. The tapered portion on the outer periphery of the hole portion guides the seal ring more gently than the case without it, so that the seal ring is less likely to be damaged, and the passage area defined by the tapered portion, that is, the flow around the port Increase the area. Further, in order to increase the flow area of the portion following the port, for example, the inner peripheral wall portion of the support hole of the outer member that supports the first and second seal rings is raised more than the other portion of the inner peripheral wall of the support hole. It is preferable to reduce the inner diameter of the support hole.

  FIG. 1 is an example of an air circuit using an air governor which is a switching valve according to the present invention. The air governor is built in the base of the air dryer 50 and controls the opening and closing of a purge valve (one of air devices) 60 of the air dryer 50. An inlet 52 of the air dryer 50 communicates with the air compressor 70, and pressurized air is supplied from the air compressor 70. The outlet 54 of the air dryer 50 communicates with the four air tanks 91, 92, 93, 94 through the 4-circuit protection valve 80. Needless to say, the 4-circuit protection valve 80 makes the system including the air tanks 91 to 94 independent. Therefore, even if a failure such as a piping failure occurs in one of the four systems, it does not adversely affect other systems. The air compressor 70 of this air circuit has no unload valve, and air is not supplied from the air governor. This air circuit is a so-called delivery load type, and the air governor keeps the air pressure in each of the air tanks 91 to 94 at a specified level by opening and closing the purge valve 60.

  2 and 3 are cross-sectional views of an air governor (switching valve) according to an embodiment of the present invention, and each drawing shows different switching states. The air governor 10 includes a block-shaped housing 500 and a cap 510 provided on one surface of the housing 500. An O-ring 520 is provided at the attachment portion of the cap 510 and hermetically seals the inside and outside of the cap 510. The inside of the cap 510 is a space for receiving the control spring 220.

  The housing 500 has an air inlet 102, an air outlet 104, and an exhaust port 106, in addition to a cylinder hole 550 that is aligned with the control spring 220. They communicate with the cylinder bore 550. The cylinder hole 550 opens on one surface of the cap 510 side, and continues from the opening side toward the back of the hole in order of a large diameter hole portion 555, a medium diameter hole portion 553, and a small diameter hole portion 551. These large, medium, and small diameter hole portions 555, 553, and 551 have the same axis and extend in a straight line. With respect to such a cylinder hole 550, the air inlet 102 is located in the middle of the large-diameter hole portion 555, the air outlet 104 is located at the bottom of the small-diameter hole portion 551, and the exhaust port 106 is opposite to the air inlet 102. Located on the side.

  A piston 210 as an outer member is movably fitted over the large-diameter hole portion 555 where the opening of the air inlet 102 faces (that is, the hole portion near the cap 510). The piston 210 holds an O-ring 212 on its outer periphery, and a large-diameter hole portion 555 is vertically divided by the sealing function of the O-ring 212. In addition, the auxiliary piston 310 is also movably fitted below the large-diameter hole portion 555. The auxiliary piston 310 also holds an O-ring 312 on its outer periphery, and divides the lower region of the large-diameter hole portion 555 vertically by the sealing function of the O-ring 312. The piston 210 and the auxiliary piston 310 that are vertically adjacent to each other define an inlet chamber that receives air supplied from the air inlet 102 between the pistons by O-rings 212 and 312. The piston 210 and the auxiliary piston 310 further have support holes 214 and 314 that pass through the center. A rod-shaped slide valve body 400 is fitted in the support holes 214 and 314.

  In addition, the middle diameter hole portion 553 of the cylinder hole 550 has an O-ring 523 that separates the small diameter hole portion 551 and the large diameter hole portion 555 from each other. There is a ring plate 640 at the bottom of the large-diameter hole portion 555. The ring plate 640 functions as a stopper for the slide valve body 400 and the auxiliary piston 310 while preventing the O-ring 523 from coming off. In addition, a small spring 120 is provided in the small-diameter hole portion 551 of the cylinder hole 550, and applies an upward force to the slide valve body 400. Since the slide valve body 400 has the flange portion 402f, the force of the spring 120 can be applied to the auxiliary piston 310 side through the flange portion 402f. The spring force of the spring 120 is about 1/10 of that of the control spring 220.

  The slide valve body 400 has an internal passage 410 extending in the axial direction. One end of the internal passage 410 opens at the end of the slide valve body 400. This end is on the side of the small diameter hole portion 551, whereby the internal passage 410 communicates with the air outlet 104 through the small diameter hole portion 551. The other end on the opposite side of the internal passage 410 communicates with a port 420 in the middle of the slide valve body 400 in the axial direction. The port 420 is a hole in a direction orthogonal to the axis, and is a hole that connects the internal passage 410 and the outside of the slide valve body 400. Here, the piston 210 and the auxiliary piston 310 outside the slide valve body 400 include an O-ring that is a seal ring as a sealing means. In the present invention, first and second two seal rings 2121 and 2122 which are separated from each other in the axial direction are used as sealing means on the side of the piston 210 which is an outer member. The first and second seal rings 2121 and 2122 communicate or block the air inlet 102 side and the air outlet 104 side depending on which of the upper and lower sides of the port 420 of the slide valve body 400 is sealed.

  4A is an enlarged view of a portion 4A in FIG. 2, and FIG. 4B is an enlarged view of a portion 4B in FIG. As those enlarged views show more clearly, for example, four ports 420 that are equally spaced in the circumferential direction include a through hole 420c that penetrates the wall of the slide valve body 400 so as to be orthogonal to the axis, and the through hole. And a tapered portion 420t surrounding 420c. The taper portion 420t is inclined downward from the radially outer side of the port 420 toward the inner side. Therefore, the distance from one peripheral edge in the radial direction of the tapered portion 420 t to the other peripheral edge is the opening diameter of the port 420. The opening diameter of this port is slightly larger than the distance between the first and second seal rings 2121, 212. Therefore, the sealing portions of both seal rings 2121 and 212 do not enter the opening diameter of the port 420 at the same time. The seal rings 2121 and 2122 are supported in the mounting groove, but the inner diameter of the support hole inner peripheral wall portion 2100 having the mounting groove is smaller than the other portion of the inner peripheral wall. That is, the inner diameter of the inner peripheral wall of the support hole other than the portion 2100 having the mounting groove is larger than that of the portion 2100 having the mounting groove. Thereby, the flow area around the port 420 is increased.

  4A (and FIG. 2), the first seal ring 2121 is in an unsealed position opposite the port 420, while the second seal ring 2122 is in a sealed position away from the port 420. FIG. At that time, the air governor 10 shuts off the air inlet 102 side and the air outlet 104 side, and connects the air outlet 104 and the exhaust port 106. In this state, the purge valve 60 described above is in a closed state. When the air compressor 70 supplies compressed air, the air pressure enters the inlet chamber through the air inlet 102. The auxiliary piston 310 maintains its position by the air pressure, while the piston 210 moves in the axial direction while contracting the control spring 220 according to the air pressure. By the movement, the seal rings 2121 and 2122 on the inner peripheral side of the piston 210 get over one of the peripheral edges in the radial direction of the tapered portion 420t of the port 420, respectively. When the first seal ring 2121 is in the sealing position beyond the port 420 of the slide valve 400 and the second seal ring 2122 is in the non-sealing position facing the port 420 accordingly, the air inlet 102 and the air The outlet 104 communicates, and air pressure is output from the air outlet 104 to the purge valve 60 side. Thereafter, the air pressure from the air inlet 102 decreases according to the consumption of air, but the control piston 210 receives the spring force (return force) of the control spring 220 and returns to the original state shown in FIG. 4A.

  FIG. 5 shows another example of the arrangement of the spring 120 that applies a force to the slide valve body 400. Instead of the ring plate 640 that prevents the O-ring 523 from coming off, a cylindrical member 640 ′ having a spring receiving step on the inner peripheral side is used, so that the spring 120 of the small diameter hole portion 551 is connected to the cylindrical member 640. It is arranged on the inner circumference of '.

It is a piping diagram showing an example of an air circuit using an air governor of one example of this invention. It is sectional drawing which shows the state with the air governor which is a switching valve. It is sectional drawing which shows another state of the air governor which is a switching valve. It is an enlarged view of 4A part of FIG. It is an enlarged view of 4B part of FIG. It is a figure which shows another example of arrangement | positioning of a spring.

Explanation of symbols

10 Air governor (switching valve)
102 Air inlet 104 Air outlet 106 Exhaust outlet 210 Piston (outer member)
214 Support hole 2121 First seal ring 2122 Second seal ring 400 Slide valve body 410 Internal passage 420 Port 420c Through hole 420t Tapered portion 500 Housing 550 Cylinder hole

Claims (8)

An outer member having a support hole along the axis, a slide valve body that fits in the support hole of the outer member and moves relative to the outer member in the direction of the axis, and the slide valve body or slide valve body A port located on either one of the outer members outside, and a sealing means located on the other of the slide valve body or the outer member, the sealing means viewed in the direction of the axis, In the method of switching the flow path passing through the port depending on whether one side of the port is sealed or the other side of the port is sealed, the sealing means are separated from each other in the direction of the axis. The first and second seal rings are used, and each of the first and second seal rings is opposed to the port and does not have a sealing action; By moving between a sealing position to a sealing action apart in the direction of the axis from, characterized in that each seal ring is to prevent cross the port, switching method of the flow path by the slide valve. The flow path passing through the port includes an inlet flow path communicating from the port to an air inlet, an exhaust flow path communicating from the port to an exhaust outlet, and an outlet flow path communicating from the port to the air outlet. The switching method according to claim 1, wherein a state in which the channel and the outlet channel communicate with each other and a state in which the outlet channel and the exhaust channel communicate with each other are switched. An outer member having a support hole along the axis, and a slide valve body that fits in the support hole of the outer member and moves relative to the outer member in the direction of the axis, the inner passage extending along the axis And a slide valve body including a port connecting the internal passage and the outer peripheral side of the slide valve body, and a sealing means positioned on the inner peripheral wall side of the support hole facing the slide valve body, the sealing means A switching valve for switching a flow path passing through the port according to whether one side of the port is sealed or the other side of the port is sealed when viewed in the direction of the axis. Are first and second seal rings that are spaced apart from each other in the direction of the axis, and each of the first and second seal rings is opposed to the port and has no sealing action. Moves between the sealing position of the sealing action apart in the direction of the axis from the port, thereby characterized in that each seal ring is to prevent cross the port switching valve. The flow path passing through the port includes an inlet flow path communicating from the port to an air inlet, an exhaust flow path communicating from the port to an exhaust outlet, and an outlet flow path communicating from the port to the air outlet. 4. The switching valve according to claim 3, wherein a switching state is switched between a state in which the flow path and the outlet flow path communicate with each other and a state in which the outlet flow path and the exhaust flow path communicate with each other. The switching valve according to claim 3, wherein an opening diameter of the port is smaller than an axial distance between the first and second seal rings. The switching valve according to claim 5, wherein the port includes a through-hole orthogonal to the axis and a tapered portion surrounding the through-hole. The support hole inner peripheral wall portion of the outer member that supports the first and second seal rings rises more than other portions of the inner peripheral wall of the support hole, and the inner diameter of the support hole is small. Or one switching valve. The switching valve is an air governor, and the opening diameter of the port is large enough to supply sufficient air from the inlet channel to the outlet channel via the port. The switching valve according to claim 4, wherein the air device can be operated directly without using a relay valve.

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