JPH03260479A - Rate-of-flow control device - Google Patents

Abstract

PURPOSE:To prevent a rotary shaft from vibrating axially in a housing by furnishing a communication hole with a flow-in port, which opens from the periphery of the rotary shaft outward in the radial direction, and a flowout port which opens from the end face of the rotary shaft outward in the axial direction. CONSTITUTION:Inside of a rotary shaft 3 is provided a communication hole 32, which leads from an upstream fluid path 21 to a downstream fluid path 22 and which is equipped with a shaft hole 33 and a radial hole 34. A flow-in port 35 is formed at the rotary shaft 3 peripheral surface of the shaft hole 33 and leads to an inlet port 27 via a bearing 4. The rotary shaft 3 is also provided with a flowout hole 36. Most water flowing into a control chamber 23 will flow out from the flowout port 36, while part of the water flows into the gap between the inside surface of a housing 2 and the periphery of the bearing 4 and also the gap between the bore of the bearing 4 and the periphery of the rotary shaft 3 so as to prevent it from vibrating in the axial direction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flow rate control device that controls the flow rate of fluid flowing in a fluid passage, for example, a water flow rate control device that controls the amount of water supplied to a heat exchanger for a water heater. Alternatively, the present invention relates to a flow rate control device suitable for use in a fuel amount control device that controls the amount of fuel supplied to a burner.

[Prior Art] Conventionally, as a flow I control device, there is a water amount control device that controls the amount of water supplied to a heat exchanger for a water heater, for example. Such a water flow control device uses a servo motor to rotate and displace a rotary shaft rotatably supported in a housing, thereby controlling the degree of communication between the communication hole formed in the rotary shaft and the fluid passage, that is, the fluid passage. The amount of water is controlled by changing the opening area.

The inflow port of the communication hole opens axially outward from the end surface of the rotating shaft, while the outflow port opens radially outward from the outer peripheral surface of the rotating shaft.

[Problems to be Solved by the Invention] However, in the conventional water flow control device described above, when water flows into the communication hole from the upstream fluid passage, the inflow port opens outward in the axial direction. Therefore, the rotating shaft receives large water pressure in the axial direction. For this reason, there has been a problem in that the rotating shaft vibrates in the axial direction within the housing, causing load movement, resulting in wear between the housing and the rotating shaft.

SUMMARY OF THE INVENTION An object of the present invention is to provide a flow control device that can prevent abrasion between the housing and the rotating shaft by preventing load movement due to axial vibration of the rotating shaft within the housing.

[Means for Solving the Problems] A flow rate control device of the present invention includes a housing including a Sal chamber communicating with a fluid passage, disposed within the control chamber, rotatably supported by the housing, A rotating shaft having a communication hole therein that communicates the fluid passageway upstream of the control chamber with the fluid passageway downstream thereof, and changing the opening area of the fluid passageway by rotationally displacing the rotating shaft. In the flow rate control device, the communication hole opens radially outward from the outer circumferential surface of the rotating shaft, and the communication hole is configured to have an inflow rate that allows fluid to flow in from the fluid passageway upstream of the control chamber. A technical means including a port and an outflow port that opens axially outward from the end face of the rotating shaft and flows out the fluid into the fluid passage downstream from the control chamber is adopted.

[Operation] When the rotating shaft is rotationally displaced by the changing means and the fluid passage on the upstream side of the control chamber matches the inflow port of the communication hole of the rotating shaft, fluid flows from the fluid passage on the upstream side of the control chamber into the control chamber. flows into. Most of the fluid that enters the Ilf control chamber flows into the inflow port of the communication hole formed on the outer peripheral surface of the rotating shaft.

Further, a portion of the fluid flowing into the control chamber flows into a gap between the inner circumferential surface of the housing and the outer circumferential surface of the rotating shaft, which is necessary for the rotation of the rotating shaft with respect to the housing. Therefore, the pressure of the fluid is applied to the outer peripheral surface of the rotating shaft and not in the axial direction of the rotating shaft.

[Effects of the Invention] Since the pressure of the fluid flowing into the control chamber from the upstream fluid passage is not applied in the axial direction of the rotating shaft, it is possible to prevent the load from shifting due to the rotating shaft vibrating in the axial direction within the housing. Therefore, wear between the housing and the rotating shaft can be reduced.

In addition, since the pressure of the fluid flowing into the control chamber from the upstream fluid passage is applied almost uniformly over the entire circumference of the rotating shaft,
Since the rotating shaft is deflected with respect to the control chamber of the housing, the rotating shaft does not rattle, so that wear between the housing and the rotating shaft can be reduced.

[Embodiment] The flow rate control device of the present invention will be explained based on an embodiment shown in FIGS. 1 to 4.

FIG. 1 and FIG. 4 show a water amount control device for controlling the amount of water supplied to a heat exchanger for a water heater employing the present invention.

This water I control device W1 includes a housing 2, a rotating shaft 3, a bearing 4, a seal member 5, and a servo motor 6.

The housing 2 has a cylindrical shape and includes an upstream fluid passage 2 therein.
1. A downstream fluid passage 22 and a control chamber 23 are formed. This housing 2 has flange portions 24 and 25 fastened to a fixing member (not shown) provided on the water heater.

The upstream fluid passage 21 is formed in the radial direction with respect to the rotating shaft 3, and its upper end in the figure serves as a connection part 26 with a water pipe (not shown) that connects a public water pipe and the housing 2, and its lower end in the figure is an inlet port 27 facing the control room 23.

The downstream fluid passage 22 is formed coaxially with respect to the rotating shaft 3, and the left end in the figure serves as an outlet port 28 facing the control room 23, and the right end in the figure serves as an outlet port 28 facing the water heater heat exchanger (not shown) and the housing 2. Connection part 2 with water supply piping (not shown) that connects
It is said to be 9.

A rotating shaft 3 and a bearing 4 are arranged within the control room 23 .

The rotating shaft 3 is disposed within the control chamber 23 and rotatably supported on the inner circumferential surface of the housing 2 via a bearing 4. The left end of the rotating shaft 3 in the drawing is a connecting portion 31 that is connected to the servo motor 6. Furthermore, a communication hole 32 is formed inside the rotating shaft 3 to communicate the upstream fluid passage 21 and the downstream fluid passage 22.

The communication hole 32 has a shaft hole 33 whose diameter is larger on the right side in the figure than on the left side in the figure, and a radial hole 34 formed in a radial direction from the left side of the shaft hole 33 in the figure.

The upstream fluid passage 21 is provided on the outer peripheral surface of the rotating shaft 3 in the shaft hole 33.
An inflow port 35 is formed through which fluid flows into the communication hole 32. The inflow port 35 opens radially outward from the outer circumferential surface of the rotating shaft 3 and communicates with the inlet port 27 of the upstream fluid passage 21 via the bearing 4 .

An outflow port 36 that allows fluid to flow out from the communication hole 32 to the downstream fluid passage 22 is provided on the right end surface of the rotation shaft 3 of the shaft hole 33 in the drawing.
is formed. The outflow port 36 opens axially outward from the right end surface of the rotating shaft 3 in the drawing, and always communicates with the outlet port 28 of the downstream fluid passage 22 .

The bearing 4 has a sleeve shape and is attached to the control chamber 2 of the housing 2.
3, and rotatably holds the rotating shaft 3. This bearing 4 is connected to the inlet port 27 of the upstream fluid passage 21.
A radial hole 41 that communicates with the inflow port 35 of the rotating shaft 3
has. Furthermore, a circumferential groove 42 into which water flows is formed on the outer peripheral surface of the bearing 4.

The seal member 5 is disposed within the control chamber 23 of the housing 2 and prevents water from leaking from the control chamber 23 to the outside. The sealing member 5 of this embodiment includes three O-rings 51 to 53, one seat 54, and two backup rings 55 and 56.

The backup rings 55 and 56 are made of tetrafluoroethylene resin and are installed between the outer circumferential surface of the rotating shaft 3 and the inner circumferential surface of the bearing 4. Water is prevented from leaking from the gap to the servo motor 6 and the downstream fluid passage 22 side. These backup rings 55
．． 56 is cut diagonally with respect to the axial direction of the terminal wire (pierce cut). Therefore, the backup rings 55 and 56 have good sealing performance even if the rotating shaft 3 vibrates in the vertical direction. Does not decrease.

The servo motor 6 is a changing means of the present invention, and controls the opening area of the inlet port 27 of the upstream fluid passage 21 by displacing the rotating shaft 3 by a predetermined amount in the rotational direction according to the amount of energization. . In this servo motor 6, a motor case 62 is fastened to a mounting plate 61 fixed to the housing 2. Further, the output shaft 63 of the servo motor 6 is connected to the connecting portion 31 of the rotating shaft 3 by a spring pin 64.

The operation of the water flow control device 1 of this embodiment will be explained based on FIGS. 1 to 4.

The degree of communication between the radial hole 41 of the bearing 4 and the inflow port 35 of the communication hole 32 changes by rotating the rotation shaft by the servo motor 6, that is, the opening area of the inlet port 21 of the upstream fluid passage 21. Water with a corresponding flow rate flows from the upstream fluid passage 21 through the radial hole 41 of the bearing 4 to the control chamber 2.
It flows into 3.

Most of the water that flows into the control chamber 23 flows through the communication hole 32 from the inflow port 35 formed on the outer peripheral surface of the rotating shaft 3.
flow inside. The water that flows into the communication hole 32 from the inflow port 35 initially flows in the radial direction, but changes to an axial flow that flows into the shaft hole 33 . After flowing through the shaft hole 33, the water flows out from the outflow port 36, flows into the downstream fluid passage 22 from the outlet port 28, and is supplied to the water heater heat exchanger through the water supply pipe.

On the other hand, a portion of the water flowing into the control chamber 23 flows into the gap between the inner circumferential surface of the housing 2 and the outer circumferential surface of the bearing 4, and also flows into the gap between the inner circumferential surface of the bearing 4 and the outer circumferential surface of the rotating shaft 3. Flows into the gap.

The water that has flowed into these gaps is prevented from leaking from the control chamber 23 to the servo motor 6 side and the downstream fluid passage 22 side by the O-ring 51.53 and the two backup rings 55.56. Therefore, the water pressure of the water flowing into the communication hole 32 from the rotary shaft 3 is not applied to the rotary shaft 3 and the bearing 4 in the axial direction, so that the bearing 4 does not vibrate in the axial direction.

Furthermore, since the pressure of the water flowing into these gaps is applied almost uniformly over the entire circumference of the rotating shaft 3 and the bearing 4, the rotating shaft 3 is held down in the downward direction in the figure by the water pressure of the water flowing into the communication hole 32. You won't be disappointed.

That is, since the rotary shaft 3 is not deflected with respect to the fine details of the control chamber 23, wear due to interference between the lower outer peripheral surface of the rotary shaft 3 in the drawing and the lower inner peripheral surface of the bearing 4 in the drawing can be prevented.

Further, a portion of the water that has flowed into the communication hole 32 flows from the left side portion of the shaft hole 33 through the radial hole 34 into the gap between the inner circumferential surface of the bearing 4 and the outer circumferential surface of the rotating shaft 3. This can prevent the rotating shaft 3 from shaking within the bearing 4.

That is, by preventing the vibration of the rotating shaft 3 and the bearing 4 in the axial direction and thereby preventing the movement of the load, the wear of the rotating shaft 3 and the bearing 4 of the housing 21 can be reduced, thereby significantly improving the durability. Water flow control device 1
can be provided.

(Modified example) In this embodiment, the present invention was used for a water amount control device that controls the amount of water supplied to a heat exchanger for a water heater. It's okay.

In this embodiment, a servo motor is used as the changing means, but an actuator or the like that rotationally shifts the rotating shaft using hydraulic pressure or the like may also be used.

The fluid passage on the upstream side may be connected to a water supply pipe that connects the heat exchanger and the housing, and the fluid passage on the downstream side may be connected to a water supply pipe that connects the housing and a hot water supply place such as a bath or kitchen. It may be connected to.

[Brief explanation of drawings]

Figures 1 and 4 show a water flow control device employing the present invention, Figure 1 is a sectional view of the water flow control device, Figure 2 is a side view of the water flow control device, and Figure 3 is a water flow control device. FIG. 4 is another side view showing the water flow control device. In the diagram 1...Water flow control device (flow rate control device) 3...
・Rotating shaft 6... Servo motor stage) 21... Upstream fluid passage (fluid passage) Stream side fluid passage (fluid passage) 23.
...Control room through hole 35...Inflow port 36...Outflow port 2...How (changer 22...lower 32...connection)

Claims (1)

[Scope of Claims] 1) A housing provided with a control chamber communicating with a fluid passage, the housing being disposed within the control chamber and rotatably supported by the housing, and containing a portion upstream of the control chamber. Flow rate control comprising: a rotating shaft provided with a communication hole that communicates the fluid passageway with the fluid passageway on the downstream side; and a changing means for rotationally displacing the rotating shaft to change an opening area of the fluid passageway. In the device, the communication hole opens radially outward from the outer peripheral surface of the rotating shaft,
an inflow port that allows fluid to flow in from the fluid passageway upstream from the control chamber; and an inflow port that opens axially outward from an end surface of the rotating shaft and allows fluid to flow out into the fluid passageway downstream from the control chamber. A flow control device characterized by comprising an outflow port.