JP2020159439A - Rotary switching valve - Google Patents

Abstract

To prevent degradation of sealability of packing parts positioned at a front side in a rotating direction of a valve element in a rotary switching valve which includes a valve casing 1 provided with a valve chest 11 having a cylindrical peripheral face, an axial port communicated with an axial one end of the valve chest, and a radial port 131 opened to a part in a circumferential direction of a peripheral face of the valve chest, and a valve element 2 rotatably disposed in the valve chest, ans is further provided with a valve opening 22 capable of communicating an internal space of the valve element and the radial port by rotation of the valve element on a peripheral wall portion 21 of the valve element, and in which an annular packing 5 is disposed on an annular packing mounting groove 4 formed at the circumference of the opening end to the valve chest, of the radial port.SOLUTION: Projecting portions 41a projecting to an inner peripheral side of the packing mounting grooves 4, are disposed on tip portions at a valve chest 11 side, of parts positioned, at least, at both sides in a rotating direction of the valve element 2 of an outer peripheral-side groove wall 41 of the packing mounting groove 4. Tip portions at the valve chest 11 side, of packings 5 are pressed by the projecting portions 41a.SELECTED DRAWING: Figure 6

Description

In the present invention, a valve chamber having a cylindrical peripheral surface, an axial port communicating with one end in the axial direction of the valve chamber, and at least one radial port opening in a part of the peripheral surface of the valve chamber in the circumferential direction are provided. A valve housing having a valve housing and a valve body having a cylindrical peripheral wall portion rotatably provided in the valve chamber are provided, and one axial end of the valve body always communicates with the internal space of the valve body and the axial port. The present invention relates to a rotary switching valve in which a valve opening is formed on the peripheral wall portion of the valve body so that the internal space of the valve body and the radial port can be communicated with each other by the rotation of the valve body.

Conventionally, in this type of rotary switching valve, an annular packing in contact with the outer peripheral surface of the peripheral wall portion of the valve body is mounted in an annular packing mounting groove provided around the opening end of the radial port with respect to the valve chamber. The packing prevents the fluid from leaking from the radial port into the gap between the outer peripheral surface of the peripheral wall portion of the valve body and the peripheral surface of the valve chamber (see, for example, Patent Document 1).

Here, the tip surface of the packing that is in sliding contact with the peripheral wall portion of the valve body is a curved surface that is curved in an arc shape over the outer peripheral surface and the inner peripheral surface of the packing in a free state. Therefore, a gap is generated between the curved surface at the tip of the packing and the tip of the groove wall on the outer peripheral side of the packing mounting groove. Then, when the valve body is rotated, the tip of the packing portion located on the front side in the rotation direction of the valve body escapes to the front side in the rotation direction of the valve body by the frictional force from the valve body, and the seal of this portion is sealed. The sex gets worse.

JP-A-2018-1686969

In view of the above points, it is an object of the present invention to provide a rotary switching valve capable of preventing deterioration of the sealing property at the packing portion located on the front side in the rotation direction of the valve body.

In order to solve the above problems, the present invention opens a valve chamber having a cylindrical peripheral surface, an axial port communicating with one end in the axial direction of the valve chamber, and a part of the peripheral surface of the valve chamber in the circumferential direction. A valve housing having at least one radial port and a valve body having a cylindrical peripheral wall portion rotatably provided in the valve chamber are provided, and one axial end of the valve body is the internal space and axis of the valve body. It is a rotary switching valve that is open so as to always communicate with the directional port and has a valve opening formed on the peripheral wall of the valve body so that the internal space of the valve body and the radial port can be communicated by the rotation of the valve body. In the case where the annular packing in contact with the outer peripheral surface of the peripheral wall portion of the valve body is mounted in the annular packing mounting groove provided around the opening end of the radial port with respect to the valve chamber, the outer peripheral side groove wall of the packing mounting groove is mounted. Of these, protrusions protruding toward the inner peripheral side of the packing mounting groove are provided at the tip of the portion located on both sides of the valve body in the rotation direction on the valve chamber side, and are located on at least both sides of the valve body in the rotation direction of the packing. The outer peripheral surface of the portion is characterized in that the tip end portion on the valve chamber side is in contact with the protrusion.

According to the present invention, even if a frictional force from the valve body to the front side in the rotation direction acts on the tip portion of the packing portion located on the front side in the rotation direction of the valve body, the tip portion is the outer peripheral side groove wall of the packing mounting groove. Since the protrusions provided at the tip of the corresponding portion are pressed from the front side in the rotation direction, the tip does not escape to the front side in the rotation direction. Therefore, it is possible to prevent deterioration of the sealing property at the packing portion located on the front side in the rotation direction of the valve body.

Further, in the present invention, it is desirable that the protrusion is formed in a tapered shape in which the amount of protrusion of the packing mounting groove toward the inner peripheral side gradually increases toward the valve chamber. According to this, the tip end portion of the outer peripheral surface of the packing is likely to come into contact with the protrusion portion, and it is difficult to form a gap between the packing and the protrusion portion, and the sealing property is improved.

By the way, the outer peripheral side groove wall of the packing mounting groove, the inner peripheral side groove wall of the packing mounting groove surrounding the opening end of the radial port with respect to the valve chamber, and the bottom of the packing mounting groove that receives the base end opposite to the valve chamber side of the packing. Although it is possible to integrally form the wall with the valve housing, only the outer peripheral side groove wall of the packing mounting groove is integrally formed with the valve housing, and an annular having an inner peripheral side groove wall and a bottom wall portion of the packing mounting groove. The packing mounting member may be provided, and the packing mounting member may be fitted and fixed to the valve housing at the radial port.

The cutting side view of the rotary switching valve of embodiment of this invention. The cut plan view cut by II-II of FIG. The perspective view of the valve body provided in the rotary switching valve of an embodiment. The perspective view of the packing and the packing mounting member provided in the rotary switching valve of an embodiment. The perspective view of the state in which the upper half part of the valve casing provided in the rotary switching valve of an embodiment is cut off. An enlarged cut-out plan view of a main part of the rotary switching valve of the embodiment.

The rotary switching valve of the embodiment of the present invention shown in FIGS. 1 and 2 has a valve chamber 11 having a cylindrical peripheral surface and an axial port communicating with an axial end (lower end of FIG. 1) of the valve chamber 11. 12, comprises a valve housing 1 having a first and a ₂ second pair of radial ports 13 _1, 13 which is open in the circumferential direction two portions of the circumferential surface of the valve chamber 11. Incidentally, the rotary switching valve, the mixing ratio of the first fluid and the second fluid flow from the second radial port 13 ₂ axially port 12 to flow from the first radial port 13 ₁ in the axial direction port 12 mixing valve for switching, or is to use as a distribution valve for switching the distribution ratio of the first radial port 13 ₁ of the fluid flowing axially port 12 and the second radial port 13 _2.

The rotary switching valve further includes a valve body 2 having a cylindrical peripheral wall portion 21 rotatably provided in the valve chamber 11. With reference to FIG. 3, one end of the valve body 2 in the axial direction is open so as to always communicate with the internal space of the valve body 2 and the axial port 12. Further, the peripheral wall 21 of the valve body 2, the interior space and first and second respective radial ports 13 _1, 13 ₂ and communicable a single valve opening in the valve body 2 by the rotation of the valve body 2 22 is formed. A valve shaft 23 is erected on the end wall of the other end of the valve body 2 in the axial direction. Then, the valve shaft 23 is connected to the motor 3 mounted on the outer surface of the valve housing 1, and the valve body 2 is rotated by the motor 3.

Further, a stopper protrusion 24 inserted into the arcuate groove 14 formed on the other end surface of the valve chamber 11 in the axial direction is projected at one position on the outer peripheral portion of the end wall at the other end in the axial direction of the valve body 2. .. The rotation range of the valve body 2 is limited by the stopper protrusions 24 contacting both ends of the arcuate groove 14.

The valve body 2 is further provided with a reinforcing rib 25 extending in the axial direction along the radial direction of the valve body 2 passing through the circumferential intermediate portion of the valve opening 22. Here, when the valve opening 22 is the peripheral wall 21 of the circumferential portions having no closed first and one second each radial port _13, 13 ₂ opposed each radial port 13 1 to _{13 2} , each radial port ₁₃ 1, 13 the ₂ parts of the opposing wall portions 21 to flex pushed in the radial direction side to the fluid pressure of each radial port ₁₃ 1, 13 _2, each radial port ₁₃ 1, 13 results in ₂ of the seal failure. Reinforcing ribs 25 serve to prevent the poor sealing of the radial ports ₁₃ 1, 13 ₂ as will be described later.

By the way, if the diameter of the valve body 2 is also reduced in order to reduce the size of the valve, the passage resistance in the valve body 2 becomes large. Therefore, the portion of the peripheral wall portion 21 of the valve body 2 adjacent to the one end side in the axial direction of the valve opening 22 (the lower end side in FIGS. 1 and 3, that is, the axial port 12 side) is set from the circumferential range of the valve opening 22. It is notched except for the peripheral wall portion 21a in a predetermined circumferential range centered on the reinforcing rib 25, which is also narrow. The notched portion of the peripheral wall portion 21 is shown by a two-dot chain line in FIG. According to this, in the portion where the peripheral wall portion 21 is cut out, the passage area between the peripheral wall portion 21 and the axial port 12 is increased by the thickness of the peripheral wall portion 21, and the passage resistance in the valve body 2 due to the reduction in the diameter of the valve body 2. Can be suppressed from increasing.

Incidentally, when the peripheral wall portion 21 of the circumferential portions having no valve opening 22 is opposed to the first and the diameter of the second direction port 13 _1, 13 _2, each radial port acting on the portion of the peripheral wall 21 13 _1, 13 ₂ of the fluid pressure can be received by the peripheral wall portion 21a through the reinforcing ribs 25. Therefore, it is possible to prevent causing poor sealing at the deflection of the portion of each radial port 13 _1, 13 ₂ opposed to the peripheral wall portion 21.

Around the open end with respect to the first and second respective radial ports 13 _1, 13 ₂ of the valve chamber 11, an annular packing mounting groove 4 is provided. An annular packing 5 in contact with the outer peripheral surface of the peripheral wall portion 21 of the valve body 2 is mounted in each packing mounting groove 4. Each packing mounting groove 4 and each packing 5 has an annular shape as seen from the valve chamber 11 side.

Further, in the present embodiment, the outer peripheral side groove wall 41 of each packing mounting groove 4 is integrally formed with the valve housing 1. On the other hand, receives an inner circumferential side groove wall 42 of the packing mounting groove 4 surrounding the open end, the valve chamber 11 side opposite to the base end portion 51 of the gasket 5 with respect to each radial port 13 _1, 13 ₂ of the valve chamber 11 the bottom wall 43 of each packing mounting groove 4, the valve housing 1 separately, are formed in each packing mounting member 6 of an annular that is fitted and fixed to the valve housing 1 in each radial port 13 _1, 13 ₂ ing.

With reference to FIG. 4, four claws 62 elastically deformable in the radial direction of the tubular portion 61 extend outward from the bottom wall 43 portion of each packing mounting member 6. Is provided. Further, as shown in FIG. 5, the peripheral surface of the radial port ₁₃ 1, 13 _2, grooves 131 corresponding to the respective claw portions 62 are formed. Then, in a state in which each gasket 5 in the circumferential groove wall 42 within which is formed in each packing mounting member 6 was fitted to, when inserted from the outside of each packing mounting member 6 on each radial port 13 _1, 13 ₂ , where each packing mounting member 6 has reached a predetermined set position, the pawl portions 62 are engaged enters elastically in the groove 131, in each packing mounting members 6 each radial port 13 _1, 13 ₂ It is fitted and fixed to the valve housing 1.

The base end portion 51 of each packing 5 is formed in a flange shape that bends toward the outer peripheral side. Further, on the outer periphery of the radial ports 13 _1, 13 _2, by positioning the proximal end of the portion to be the outer periphery side groove wall 41 of the packing mounting groove 4, to form a step 132 that faces outward. When each packing mounting member 6 reaches the set position, the flange-shaped base end portion 51 of each packing 5 is sandwiched between the step 132 and the bottom wall 43.

Further, a ridge 63 is provided at a diagonal position on the outer surface of the tip end portion of the tubular portion 61 of each packing mounting member 6. On the other hand, the diagonal positions of the peripheral surface of the radial port ₁₃ 1, 13 _2, a groove portion 133 projecting 63 extending in the longitudinal direction of the engageable radial ports ₁₃ 1, 13 ₂ are formed .. Then, each packing mounting member 6 is phase-determined by engaging the protrusion 63 with the groove portion 133.

By the way, the tip surface of each packing 5 that is in sliding contact with the peripheral wall portion 21 of the valve body 2 is in a free state, and as shown in the virtual line of FIG. 6 and FIG. It is a curved surface curved in an arc shape in cross section. Therefore, when the outer periphery side groove wall 41 of the packing mounting groove 4 is formed in a true face parallel to each radial port 13 _1, 13 ₂ of the axis over the front end portion of the valve chamber 11 side, of the gasket 5 A gap is created between the curved tip surface and the tip end portion of the outer peripheral side groove wall 41 of each packing mounting groove 4. Then, when the valve body 2 is rotated, the tip of the packing portion 5a located on the front side in the rotation direction of the valve body 2 is the front side in the rotation direction of the valve body 2 by the frictional force from the valve body 2. It escapes to, and the sealing property of this part deteriorates.

Therefore, in the present embodiment, the outer peripheral side groove wall 41 of each packing mounting groove 4 is located at the tip of the portion located on both sides of the valve body 2 in the rotation direction on the valve chamber 11 side, and is located on the inner peripheral side of each packing mounting groove 4. A protruding portion 41a is provided. The tip of each packing 5 on the valve chamber 11 side of the outer peripheral surface of the portion located on both sides of the valve body 2 in the rotation direction is pressed against the protrusion 41a as shown by a solid line in FIG.

According to this, even if a frictional force from the valve body 2 to the front side in the rotation direction acts on the tip portion of the packing portion 5a located on the front side in the rotation direction of the valve body 2, the tip portion is the outer periphery of the packing mounting groove 4. Since the protrusion 41a provided at the tip of the corresponding portion of the side groove wall 41 is pressed from the front side in the rotation direction, the tip does not escape to the front side in the rotation direction. Therefore, it is possible to prevent deterioration of the sealing property at the packing portion 5a located on the front side in the rotation direction of the valve body 2.

Further, in the present embodiment, the protrusion 41a is formed in a tapered shape in which the amount of protrusion of the packing mounting groove 4 toward the inner circumference gradually increases toward the valve chamber 11. According to this, the tip end portion of the outer peripheral surface of the packing 5 is likely to come into contact with the protrusion 41a, and it is difficult to form a gap between the packing 5 and the protrusion 41a, and the sealing property is improved.

Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited thereto. For example, in the above embodiment, the protrusions 41a located at the tip on the valve chamber 11 side are formed only on the outer peripheral side groove walls 41 of each packing mounting groove 4 located on both sides of the valve body 2 in the rotation direction. However, a protrusion 41a located at the tip end on the valve chamber 11 side may be formed on the outer peripheral side groove wall 41 of each packing mounting groove 4 over the entire circumference. Further, in the above embodiment, the packing mounting member 6 having the inner peripheral side groove wall 42 and the bottom wall 43 of the packing mounting groove 4 is provided, but the packing mounting member 6 is omitted and the outer peripheral side groove wall of the packing mounting groove 4 is provided. In addition to 41, the inner peripheral side groove wall 42 and the bottom wall 43 can be integrally formed in the valve housing 1.

Further, in the above embodiment, the first and second two radial ports 13 1 to the valve housing _1, 13 is ₂ is provided, provided with a single radial port, axial port and a radial direction The present invention can also be applied to a rotary switching valve that communicates with and shuts off a port and switches the flow rate of a fluid flowing between both ports. Further, the rotary switching valve of the above embodiment is an electric type in which the valve body 2 is rotated by a motor 3, but may be a manual type.

1 ... valve housing, 11 ... valve chamber, 12 ... axial port, 13 ₁ , 13 ₂ ... radial port, 2 ... valve body, 21 ... peripheral wall, 22 ... valve opening, 4 ... packing mounting groove, 41 ... packing Outer peripheral groove wall of the mounting groove, 41a ... Projection, 42 ... Inner peripheral groove wall of the packing mounting groove, 43 ... Bottom wall of the packing mounting groove, 5 ... Packing, 51 ... Packing base end, 6 ... Packing mounting member.

Claims (3)

A valve housing having a valve chamber having a cylindrical peripheral surface, an axial port communicating with one end in the axial direction of the valve chamber, and at least one radial port opening in a part of the peripheral surface of the valve chamber in the circumferential direction. It is equipped with a valve body having a cylindrical peripheral wall portion rotatably provided in the valve chamber, and one end in the axial direction of the valve body is opened so as to always communicate with the internal space of the valve body and the axial port. A rotary switching valve in which a valve opening is formed on the peripheral wall of the valve body so that the internal space of the valve body and the radial port can be communicated with each other by the rotation of the valve body.
In the case where the annular packing in contact with the outer peripheral surface of the peripheral wall of the valve body is mounted in the annular packing mounting groove provided around the opening end of the radial port with respect to the valve chamber.
A protrusion protruding toward the inner peripheral side of the packing mounting groove is provided at the tip of the groove wall on the outer peripheral side of the packing mounting groove, which is located at least on both sides in the rotation direction of the valve body, on the valve chamber side.
A rotary switching valve characterized in that the tip of the outer peripheral surface of the packing, which is located on both sides of the valve body in the rotation direction, is in contact with the protrusion. The rotary switching valve according to claim 1, wherein the protruding portion is formed in a tapered shape in which the amount of protrusion of the packing mounting groove toward the inner peripheral side gradually increases toward the valve chamber. The outer peripheral side groove wall of the packing mounting groove is integrally formed with the valve housing, and the inner peripheral side groove wall of the packing mounting groove surrounding the opening end of the radial port with respect to the valve chamber and the base end portion opposite to the valve chamber side of the packing are formed. The rotary switching according to claim 1 or 2, wherein an annular packing mounting member having a bottom wall of the packing mounting groove to be received is provided, and the packing mounting member is fitted and fixed to the valve housing at the radial port. valve.

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