JP2019090522A - Flow channel changeover valve - Google Patents

Abstract

To provide a flow channel changeover valve restricting the wear degradation over time, increase in size and in cost of manufacture of a valve body.SOLUTION: A flow channel changeover valve comprises: a casing having a pair of end walls for closing both ends of tubular type peripheral side wall and a cylinder; an input formed on the peripheral wall of the casing; a pair of outputs formed on the casing peripheral side wall at circumferential direction intervals; and a valve assembly having a valve body disposed in the casing for opening/closing the outputs, and a rotary shaft to which the valve body is attached and one end is inserted in a shaft insertion hole formed in one of the casing end walls and the other end is rotatably supported by the other of the casing end walls. The valve body has a cam rod; and the casing end wall has cam grooves. The cam grooves include: a central part that forms an arc with a constant radius of curvature; and both ends curved radially outward from both ends of the central part. One of both ends faces one of the outlets and the other of both ends faces the other of the outlets.SELECTED DRAWING: Figure 3

Description

The present invention relates to a flow path switching valve.

A casing having an oval cylindrical peripheral side wall and a pair of end walls closing both ends of the oval cylinder, an inlet formed on the casing peripheral side wall of the elliptical long diameter portion, and a casing peripheral side wall of the elliptical short diameter portion A pair of formed outlet, valve body disposed in the casing to open and close the outlet, and a valve are attached, and one end is inserted into the shaft insertion hole formed in one of the casing end walls, and the other end is And a valve assembly having a rotary shaft rotatably supported by the other of the casing end walls, the valve body having a length of cam rod, the end wall of the casing having a cam groove, and a cam groove Is a circular arc having a constant radius of curvature, one of the two ends of the cam groove faces one of the outlets, the other of the two ends faces the other of the outlets, It is disclosed in Patent Document 1.
In the flow path switching valve of Patent Document 1, when the rotary shaft rotates, the valve body moves along the cam groove, and when it moves to either end of the cam groove, the outlet facing the end is Close.
In the flow path switching valve of Patent Document 1, a pair of outlets are formed opposite to the casing circumferential side wall of the elliptical short diameter portion, while the cam groove forms a circular arc having a certain curvature radius, so the valve body Is advantageous in that it can be in contact with the outlet formed in the elliptical short diameter portion, and can be separated from the circumferential side wall when passing through the elliptical long diameter portion to move to the opposite opposite outlet.

Patent No. 5864171

In the flow path switching valve of Patent Document 1, when the valve body moves in the vicinity of the outlet, it slides on the casing peripheral wall with a large surface pressure over a relatively large angle area, so the valve body surface wears and deteriorates over time There is a problem that it is easy to do, and the elliptical cylinder has a problem that it causes the flow path switching valve to be larger than a cylinder, and it takes more man-hours to manufacture the casing of the elliptic cylinder and the manufacturing cost increases. There's a problem.
This invention is made in view of the said problem, and an object of this invention is to provide the flow-path switching valve by which the time-dependent wear degradation of the valve body, the enlargement, and the raise of manufacturing cost were suppressed.

In order to solve the above problems, in the present invention, a casing having a cylindrical circumferential side wall and a pair of end walls closing both ends of the cylinder, an inlet formed in the casing surrounding wall, and a circumferentially spaced apart A shaft insertion hole having a pair of outlets formed on the casing circumferential side wall, a valve body disposed in the casing for opening and closing the outlet, and a valve body having one end formed in one of the casing end walls And a valve assembly having a rotary shaft, the other end of which is rotatably supported by the other of the casing end walls, the valve body having a cam rod, the casing end wall having a cam groove, The cam groove has a central portion forming a circular arc having a constant radius of curvature, and both ends curved radially outward from both ends of the central portion, one of the opposite ends facing one of the outlet, the both ends That the other of the two faces the other of the outlet It provides a flow path switching valve according to symptoms.
The cam groove has a central portion forming a circular arc having a constant radius of curvature, and both ends curved radially outward from both ends of the central portion, one of the opposite ends facing one of the outlet, the both ends Since the other of the two faces the other of the outlet, the valve body is pushed radially outward when it moves to both ends of the cam groove, and a large biasing force is exerted on the valve seat formed by the portion around the outlet on the inner peripheral surface of the casing. To close the outlet. When the valve moves in the central part of the cam groove, it moves radially inward rather than when the outlet is closed, so it does not come in sliding contact with the inner surface of the casing circumferential wall, even in the case of sliding contact. Is small. The inlet may be formed on either the end wall or the circumferential side wall of the casing.
The valve body approaches the outlet through a circular arc having a constant radius of curvature, and is pushed radially outward in the vicinity of the outlet and abuts against the outlet, so that the valve body has a large surface pressure against the casing circumferential wall The sliding angle area is very small. As a result, wear and deterioration over time of the valve body surface are suppressed. Since the casing is a cylindrical body, the flow path switching valve is not increased in size, and the manufacturing cost is not increased. The slight increase in manufacturing cost due to slight deformation of both ends of the cam groove is small.

In a preferred aspect of the present invention, the valve body is radially slidably mounted on the rotating shaft.
By attaching the valve body to the rotating shaft so as to be slidable in the radial direction, the valve body can smoothly follow the difference in radial position between the center portion and the both end portions of the cam groove.
In a preferred aspect of the present invention, each of the pair of end walls of the casing has a cam groove, and the valve body has a pair of cam rods engaged with the pair of cam grooves.
Since the valve body is guided by the pair of cam rods and the pair of cam grooves, the movement of the valve body is stabilized.

It is a structural drawing of a part of casing of a flow-path switching valve concerning an example of the present invention, more specifically a bottom wall in which an inflow port was formed, and a peripheral side wall in which a pair of outflow ports were formed. (A) is a top view, (b) is a b-b arrow view of (a), and (c) is a c-c arrow view of (a). It is a structural view of a part of casing of a flow-path switching valve concerning an example of the present invention, more specifically a top wall. (A) is a top view, (b) is a bb arrow view of (a), and (c) is a bottom view. It is a block diagram of the flow-path switching valve concerning the Example of this invention. (A) is a side sectional view, (b) is a front view of the valve body, (c) is a view taken in the direction of the arrow c-c of (b), (d) is a d-d of (b) It is an arrow view, (e) is a top view of the valve body, (f) is a bottom view of the valve body, (g) is a g-g arrow view of (a) focusing only on the rotation axis (H) is a view on h-h of (g), (i) is a top view of the rotation axis, and (j) is a bottom view of the rotation axis.

As shown in FIGS. 1 to 3, the flow path switching valve 1 is provided with a casing 2 having a cylindrical circumferential side wall 2a and a top wall 2b and a bottom wall 2c which are a pair of end walls closing both ends of the cylinder. . The bottom wall 2c is integrally formed with the circumferential side wall 2a, and the top wall 2b is formed separately from the circumferential side wall 2b and assembled to the circumferential side wall 2b.
A pair of outlet 3a _1, 3a ₂ is formed in the casing peripheral side wall 2a at intervals in the circumferential direction, the shaft insertion hole 3b is formed in the top wall 2b, inlet 3c is formed in the bottom wall 2c.
A cam groove 4b is formed on the lower surface of the top wall 2b. The cam grooves 4b has a central portion 4b ₁ of radius of curvature to form a predetermined arc, and two end portions 4b _2, 4b ₃ curved from both ends of the central portion 4b ₁ radially outward. End 4b ₂ is facing the outlet 3a _1, end 4b ₃ is facing the outlet 3a _2.
A cam groove 4c is formed on the upper surface of the bottom wall 2c so as to face the cam groove 4b on the lower surface of the top wall 2b. The cam groove 4c has a central portion 4c ₁ of radius of curvature to form a predetermined arc, and both end portions 4c _2, 4c ₃ curved from both ends of the central portion 4c ₁ radially outward. End 4c ₂ is facing the outlet 3a _1, end 4c ₃ is facing the outlet 3a _2.
As shown in FIG. 3, the flow path switching valve 1 is provided with a valve body 5 disposed in the casing ₂ for opening and closing the outlets 3a ₁ and 3a ₂ and the valve body 5 and an upper end on the casing top wall 2b. A valve assembly 7 is provided which has a rotary shaft 6 inserted into the formed shaft insertion hole 3b and the other end rotatably supported by the casing bottom wall 2c.
The valve body 5 has a face plate 5a having a substantially square front shape and a circular arc cross section, a valve disc 5b made of synthetic rubber embedded in the face plate 5a and having a circular front shape, and a pair extending in the out-of-plane direction from the upper and lower ends of the face plate 5a. And a pair of cam rods 5d extending vertically from the pair of legs 5c. The leg portion 5c has a thick center portion 5c ₁ and a pair of thin edges 5c _2.
The rotary shaft 6 has an upper end portion 6a inserted into the shaft insertion hole 3b of the top wall 2b, a lower end portion 6b rotatably supported by the bottom wall 2c, and a radial outside from the vicinity of the upper end 6a and the vicinity of the lower end 6b And a pair of leg receiving portions 6c extending in the direction. Ashi受部6c has a groove portion 6c ₁ that extends radially outward.
The valve body 5, the thick central portion 5c ₁ of the pair of leg portions 5c is by fitting into the groove 6c ₁ of the pair of legs receiving portions 6c, it is slidably attached to the rotation shaft 6 in the radial direction .

The operation of the flow path switching valve 1 will be described.
As shown in FIGS. 1 to 3, the pair of cam rods 5 d of the valve body 5 is engaged with one end 4 b ₂ , 4 c ₂ of the pair of cam grooves 4 b 4 c, and the cam groove 4 b ₂ via the cam rod 5 d the inner wall is urged from the radially outward the face plate 5a of 4c ₂ is closed the outlet 3a ₁ is pressed against the valve seat formed by the casing peripheral side wall inner surface of the outlet 3a ₁ surrounding the valve disc 5b. As a result, the inlet 3c and the outlet 3a ₂ communicate with each other.
When the motor (not shown) rotates the rotating shaft 6, move the pair of cam rod 5d and the cam grooves 4b, 4c engaged position of the one end portion _4b 2, 4c ₂ to the central part _4b 1, 4c _1, the central portion Move to the other end 4b ₃ , 4c ₃ via 4b ₁ , 4c ₁ . At this time, although the radial position of the cam rod 5d and hence the valve body 5 changes, the valve body 5 is attached to the rotary shaft 6 so as to be slidable in the radial direction. Absent. The pair of cam rods 5d of the valve body 5 engage with the other ends 4b ₃ and 4c ₃ of the pair of cam grooves 4b and 4b, and radially outward from the inner wall of the cam grooves 4b ₃ and 4c ₃ via the cam rod 5d. f-biased faceplate 5a closes the outlet 3a ₂ is pressed against the valve seat formed by the outlet 3a ₂ around the casing peripheral side wall inner surface of the valve disc 5b. As a result, the inlet 3c and the outlet 3a ₁ communicate with each other.

In the flow path switching valve 1, the cam grooves 4b and 4c are curved radially outward from one end of the central portions 4b ₁ and 4c ₁ forming an arc having a constant radius of curvature and one end of the central portions 4b ₁ and 4c ₁ the end portion _4b 2, 4c ₂ of, and an end portion _4b 3, 4c ₃ curved from the other end of the central portion _4b 1, 4c ₁ radially outwards, the ends _4b 2, 4c ₂ are outlet Since the end portions 4b ₃ and 4c ₃ face 3a ₁ and the outlet 3a ₂ faces them, the valve body 5 moves radially outward when it moves to the end 4b ₂ 4c ₂ 4b ₃ 4c ₃ of the cam groove extruded into, pressed against a large urging force to the valve seat portion of the outlet 3a _1, 3a ₂ around the casing peripheral side wall inner surface are formed, to close the outlet 3a _1, 3a _2. When moving the central portion 4b ₁ , 4c ₁ of the cam groove, the valve body 5 moves inward in the radial direction than when the outlet 3a ₁ , 3a ₂ is closed, so the inner surface of the casing circumferential side wall 2a Even in the case of sliding contact, surface pressure is small and sliding resistance is small.
The valve element 5 is the radius of curvature approaches the outlet _3a 1, 3a ₂ through a predetermined arc trajectory, the outlet _3a 1, 3a outlet _3a 1 is pushed out radially outwardly in the vicinity of _2, 3a ₂ Since the valve body 5 is in sliding contact with the casing circumferential side wall 2a with a large surface pressure, the angular region is small. As a result, wear and deterioration over time of the surface of the valve body 5, more specifically, the surface of the valve disc 5b, are suppressed. Since the casing 2 is a cylindrical body, the flow path switching valve 1 is not increased in size, and the manufacturing cost is not increased. The slight increase in manufacturing cost due to slight deformation of both ends of the cam grooves 4b and 4c.
In the flow path switching valve 1, since the valve body 5 is attached to the rotary shaft 6 so as to be slidable in the radial direction, the valve body 5 is smooth due to the difference in radial position between the central portion of the cam groove and both ends. Can follow.
The valve body 5 may be fixed to the rotary shaft 6, but in this case, the elastic deformation of the rotary shaft 6 follows the difference in the radial position.
In the flow path switching valve 1, since the valve body 5 is guided by the pair of cam rods 5d and the pair of cam grooves 4b and 4c, the movement of the valve body 5 is stable.
Although the valve body 5 may be guided by a single cam rod and a single cam groove, the movement stability of the valve body 5 is reduced.
Although the inlet is formed in the casing bottom wall 2c in the above embodiment, the inlet may be formed in the casing circumferential side wall 2a.

  The present invention is widely applicable to flow path switching valves.

1 channel switching valve 2 casing 2a peripheral side wall 2b a top wall 2c bottom 3c inlet _3a 1, 3a ₂ outlet 4b, 4c cam grooves _4b 1, 4c ₁ central _{4b 2, 4c 2, 4b 3} , 4c 3 ends Part 5 Valve body 5b Valve disc 5c Leg 5d Cam rod 6 Rotation shaft 6c Leg receiving part

Claims (3)

A casing having a cylindrical peripheral side wall and a pair of end walls closing both ends of the cylinder, an inlet formed in the casing surrounding wall, and a pair of outlets formed in the casing peripheral side wall at intervals in the circumferential direction A valve body disposed in the casing for opening and closing the outlet is attached, and one end is inserted into a shaft insertion hole formed in one of the casing end walls, and the other end is formed by the other of the casing end walls And a valve assembly having a rotatably supported rotation shaft, the valve body having a cam rod, the end wall of the casing having a cam groove, and the cam groove having a central portion forming an arc having a constant radius of curvature And both ends of the central portion curved radially outward from both ends, one of the two ends facing one of the outlets and the other of the two ends facing the other of the outlets. Flow path switching valve. 2. The flow passage switching valve according to claim 1, wherein the valve body is attached to the rotation shaft so as to be radially slidable. The flow path switching valve according to claim 1 or 2, wherein each of the pair of end walls of the casing has a cam groove, and the valve body has a pair of cam rods engaged with the pair of cam grooves.

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