JPH0686913B2 - Flow controller - Google Patents

Description

TECHNICAL FIELD The present invention relates to a flow rate control device for controlling the flow rate of a fluid flowing in a fluid passage, for example, a water amount control device for controlling 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 rate control device, for example, there is a water amount control device that controls the amount of water supplied to a heat exchanger for a water heater. In such a water amount control device, a rotary shaft rotatably supported in a housing is rotationally displaced by a servo motor, so that the communication hole formed in the rotary shaft and a fluid passage have a communication degree, that is, a fluid passage. The amount of water is controlled by changing the opening area of.

The inflow port of the communication hole opens outward in the axial direction from the end surface of the rotary shaft, while the outflow port opens outward in the radial direction from the outer peripheral surface of the rotary shaft.

[Problems to be Solved by the Invention] However, in the above-described conventional water amount control device, when water flows into the communication hole from the upstream side fluid passage, the inflow port opens outward in the axial direction. Therefore, the rotating shaft receives a large amount of water pressure in the axial direction. For this reason, there has been a problem that the load is moved by vibrating the rotary shaft in the housing in the axial direction, and the housing and the rotary shaft are worn.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a flow rate control device capable of preventing a load from moving due to an axial vibration of a rotary shaft in a housing and preventing wear between the housing and the rotary shaft.

[Means for Solving the Problems] A flow rate control device of the present invention includes a housing provided with a control chamber that communicates with a fluid passage, a housing provided in the control chamber, and rotatably supported by the housing. A rotary shaft having therein a communication hole that communicates the fluid passage on the upstream side of the control chamber and the fluid passage on the downstream side of the control chamber, and rotationally displacing the rotary shaft to change the opening area of the fluid passage. In the flow rate control device, the communication hole includes a bottomed axial hole extending in the axial direction of the rotary shaft, and a diameter of the rotary shaft from a bottom side portion of the axial hole. A radial hole that extends in a direction, opens at an outer peripheral surface in the radial direction of the rotating shaft, and allows a fluid to flow into a gap between the inner peripheral surface of the housing and the outer peripheral surface of the rotating shaft. The hole is different from the radial hole in the rotary shaft. An inflow port that opens at the outer peripheral surface in the radial direction and inflows the fluid from the fluid passage on the upstream side of the control chamber, and an opening at the axial end face of the rotating shaft, and the fluid passage on the downstream side of the control chamber. The technical means is equipped with an outflow port for outflowing the fluid.

[Operation] When the rotating shaft is rotationally displaced by the changing means and the fluid passage on the upstream side of the control chamber and the inflow port of the axial hole of the communication hole of the rotating shaft match, the fluid is on the upstream side of the control chamber. It flows into the control room from the passage. The fluid flowing into the control chamber flows into the axial hole of the communication hole from the inflow port opened on the outer circumferential surface of the rotary shaft in the radial direction. Then, most of the fluid that has flowed into the axial hole of the communication hole passes through the axial hole and flows out to the fluid passage on the downstream side of the control chamber from the outflow port opened at the axial end surface of the rotating shaft. . As a result, the pressure of the fluid that has flowed into the axial hole of the communication hole from the fluid passage on the upstream side of the control chamber is not applied in the axial direction of the rotary shaft.

Further, a part of the fluid that has flowed into the axial hole of the communication hole from the fluid passage on the upstream side of the control chamber passes through the radial hole from the bottom side portion of the axial hole, and the rotating shaft rotates with respect to the housing. It flows into the gap between the inner peripheral surface of the housing and the outer peripheral surface of the rotating shaft, which is required for movement. As a result, the pressure of the fluid flowing from the radial hole of the communication hole into the gap between the inner peripheral surface of the housing and the outer peripheral surface of the rotary shaft is also applied to the outer peripheral surface of the rotary shaft.

EFFECTS OF THE INVENTION Since the pressure of the fluid flowing into the control chamber from the fluid passage on the upstream side is not applied in the axial direction of the rotating shaft, it is possible to prevent the load from moving due to the rotating shaft vibrating in the housing in the axial direction. Therefore, wear of the housing and the rotary shaft can be reduced.

Further, the pressure of the fluid flowing from the radial hole of the communication hole into the gap between the inner peripheral surface of the housing and the outer peripheral surface of the rotary shaft is applied almost uniformly over the entire circumference of the rotary shaft, so that the pressure in the control chamber of the housing is increased. By virtue of the deflection of the rotary shaft, the rotary shaft does not rattle in the radial direction. Therefore, wear of the housing and the rotary shaft can be reduced.

[Embodiment] A flow rate control device of the present invention will be described 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 the heat exchanger for a water heater adopting the present invention.

The water amount control device 1 includes a housing 2, a rotary shaft 3, a bearing 4, a seal member 5, and a servomotor 6.

The housing 2 has a tubular shape, and the upstream side fluid passage 2 is provided inside.
1, a downstream side fluid passage 22 and a control chamber 23 are formed.
In this housing 2, flange portions 24 and 25 are fastened to a fixing member (not shown) provided in the water heater.

The upstream fluid passage 21 is formed in the radial direction with respect to the rotating shaft 3, and has an upper end shown as a connecting portion 26 for connecting a water pipe (not shown) connecting a public water pipe and the housing 2, and a lower end shown in the drawing. Is the entrance port 27 that faces the control room 23.

The downstream fluid passage 22 is formed coaxially with the rotating shaft 3, the left end in the drawing is an outlet port 28 facing the control chamber 23, and the right end in the drawing is a heat exchanger for a water heater (not shown) and the housing 2.
It is used as a connecting portion 29 with a water supply pipe (not shown) for connecting with.

The rotary shaft 3 and the bearing 4 are arranged in the control chamber 23.

The rotating shaft 3 is disposed in the control chamber 23 and is rotatably supported on the inner peripheral surface of the housing 2 via a bearing 4. The left end of the rotary shaft 3 in the drawing is a connecting portion 31 that is connected to the servomotor 6. A communication hole 32 that communicates the upstream fluid passage 21 and the downstream fluid passage 22 is formed inside the rotary shaft 3.

The communication hole 32 extends in the radial direction of the rotary shaft 3 from a bottomed axial hole 33 having a larger diameter on the right side of the figure than on the left side of the figure, and a bottom side of the axial hole 33 on the left side of the figure. The rotary shaft 3 has a radial hole 34 opened on the outer peripheral surface in the radial direction.

On the outer peripheral surface of the rotating shaft 3 of the axial hole 33, the upstream side fluid passage 21
An inflow port 35 for allowing a fluid to flow into the communication hole 32 is formed. The inflow port 35 opens on the outer peripheral surface of the rotary shaft 3 in the radial direction, and is an inlet port of the upstream fluid passage 21.
It communicates with 27 through a bearing 4.

An outflow port 36 for allowing a fluid to flow out from the communication hole 32 to the downstream fluid passage 22 is formed on the right end surface of the rotary shaft 3 in the axial hole 33 in the figure. The outflow port 36 is open at the right end surface of the rotary shaft 3 in the axial direction in the drawing, and is always in communication with the outlet port 28 of the downstream fluid passage 22.

The bearing 4 has a sleeve-like shape, and has a control chamber 23 of the housing 2.
It is fitted inside and holds the rotating shaft 3 rotatably.
The bearing 4 has a radial hole 41 that connects the inlet port 27 of the upstream fluid passage 21 and the inflow port 35 of the rotary shaft 3.
A peripheral groove 42 into which water flows is formed on the outer peripheral surface of the bearing 4.

The seal member 5 is arranged in the control chamber 23 of the housing 2 and prevents water from leaking from the control chamber 23 to the outside. The seal member 5 of the present embodiment has three O-rings.
51-53, one seat 54 and two backup rings 55, 56.

The backup rings 55 and 56 are made of tetrafluoroethylene resin, and are mounted between the outer peripheral surface of the rotating shaft 3 and the inner peripheral surface of the bearing 4 so as to connect the outer peripheral surface of the rotating shaft 3 and the inner peripheral 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. The ends of the backup rings 55 and 56 are cut obliquely (bias cut) with respect to the axial direction of the end lines. Because of this, the backup ring
The sealability of 55 and 56 does not deteriorate even if the rotary shaft 3 vibrates in the vertical direction.

The servomotor 6 is the 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 rotating 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. Also,
The output shaft 63 of the servo case 6 is connected to the connecting portion 31 of the rotary shaft 3 by a spring pin 64.

The operation of the water amount control device 1 of this embodiment will be described with reference to 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, which changes when the rotary shaft is rotated by the servomotor 6, that is, the inlet port of the upstream fluid passage 21.
A flow rate of water corresponding to the opening area of 27 flows into the control chamber 23 from the upstream fluid passage 21 through the radial hole 41 of the bearing 4.

Most of the water that flows into the control room 23 has a rotary shaft 3
Flows into the communication hole 32 from an inflow port 35 formed on the outer peripheral surface of the. The water flowing from the inflow port 35 into the communication hole 32 is
Initially, it flows in the radial direction, but it changes into an axial flow that flows into the axial hole 33. Then, the water that has finished flowing in the axial hole 33 flows out from the outflow port 36, then flows into the downstream side 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, part of the water flowing into the control chamber 23 is
It flows into the gap between the inner peripheral surface of the bearing 4 and the outer peripheral surface of the bearing 4, and flows into the gap between the inner peripheral surface of the bearing 4 and the outer peripheral surface of the rotating shaft 3.

The water that has flowed into these gaps is O-rings 51, 53 and 2
The two backup limbs 55 and 56 prevent leakage from the control chamber 23 to the servo motor 6 side and the downstream fluid passage 22 side. Therefore, the water pressure of the water flowing into the communication hole 32 from the rotary shaft 3 is not applied in the axial direction of the rotary shaft 3 and the bearing 4, so that the bearing 4 does not vibrate in the axial direction.

Further, the pressure of the water flowing into these gaps is applied almost uniformly over the entire circumference of the rotary shaft 3 and the bearing 4, so that the rotary shaft 3 is pressed downward by the water pressure of the water flowing into the communication hole 32. There is no need to be. That is, since the rotary shaft 3 is not deflected with respect to the axial center of the control chamber 23, wear due to interference between the outer peripheral surface of the rotary shaft 3 below the drawing and the inner peripheral surface of the bearing 4 below the drawing can be prevented.

Further, a part of the water that has flowed into the communication hole 32 flows into the gap between the inner peripheral surface of the bearing 4 and the outer peripheral surface of the rotary shaft 3 through the radial hole 34 from the left side portion of the axial hole 33 in the drawing. By
Since the water pressure flowing from the radial hole 34 of the communication hole 32 into the gap between the inner peripheral surface of the bearing 4 and the outer peripheral surface of the rotary shaft 3 is applied almost uniformly over the entire circumference of the rotary shaft 3, the control chamber of the housing 2 The deflection of the rotary shaft 3 with respect to 23 can prevent the rotary shaft 3 from rattling in the radial direction.

That is, by preventing vibration of the rotating shaft 3 and the bearing 4 in the axial direction and the radial direction to prevent the movement of the load, the wear of the housing 2, the rotating shaft 3 and the bearing 4 can be reduced, so that the durability is improved. It is possible to provide the water amount control device 1 in which the

(Modification) In the present embodiment, the present invention is used in the water amount control device that controls the amount of water supplied to the heat exchanger for hot water heater, but the present invention is used in the fuel amount control device that controls the amount of fuel supplied to the burner. May be.

In this embodiment, the servo motor is used as the changing means, but an actuator or the like that rotationally displaces the rotary shaft by hydraulic pressure or the like may be used.

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

[Brief description of drawings]

1 and 4 show a water amount control device adopting the present invention. 1 is a cross-sectional view showing the water amount control device, FIG. 2 is a side view showing the water amount control device, FIG. 3 is a front view showing the water amount control device, and FIG. 4 is another side view showing the water amount control device. is there. In the figure, 1 ... Water amount control device (flow rate control device), 2 ... Housing, 3 ... Rotating shaft, 6 ... Servo motor (changing means),
21 ...... upstream fluid passage (fluid passage), 22 ... downstream fluid passage (fluid passage), 23 ... control chamber, 32 ... communication hole, 33 ...
… Axial hole, 34 …… Radial hole, 35 …… Inflow port

Claims (1)

[Claims] 1. A housing having a control chamber communicating with a fluid passage, and a fluid passage disposed in the control chamber, rotatably supported by the housing, and inside the fluid passage upstream of the control chamber. And a rotation shaft having a communication hole that communicates with the fluid passage on the downstream side, and a changing unit that rotationally shifts the rotation shaft to change the opening area of the fluid passage, The communication hole is a bottomed axial hole that extends in the axial direction of the rotary shaft, and a radial direction of the rotary shaft that extends from the bottom side portion of the axial hole in the radial direction of the rotary shaft. A radial hole that opens at the outer peripheral surface of the housing and discharges fluid into a gap between the inner peripheral surface of the housing and the outer peripheral surface of the rotating shaft, wherein the axial hole is at a portion different from the radial hole. An opening is formed on the outer peripheral surface of the rotary shaft in the radial direction, and It is provided with an inflow port for inflowing a fluid from the fluid passage on the upstream side and an outflow port for opening the fluid at an axial end face of the rotating shaft and outflowing the fluid to the fluid passage on a downstream side of the control chamber. Flow control device.