JP4219770B2 - Constant flow valve with capacity adjustment function - Google Patents

Description

  The present invention relates to a constant flow valve that keeps a flow rate constant even when a primary pressure fluctuation occurs in a fluid circuit, and more particularly to a constant flow valve having a capacity adjustment function, and can be applied to, for example, a water circuit of a water heater. it can.

FIG. 8 is a cross-sectional view of a pipe joint in which a conventional constant flow valve (2) is incorporated (see FIG. 4 of Prior Literature 1).
A passage (4) through which a fluid from the upper side to the lower side in FIG. 8 flows passes through the joint body (3).

  The constant flow valve (2) which is the subject of the present invention loaded in the flow path (4) has a valve box (35) comprising a large diameter cylinder (35a) and a small diameter cylinder (35b) protruding from one end thereof. The small diameter cylinder (35b) is provided with a movable cylinder (45a) of a movable valve (45) whose downstream end is open.

  A valve port (35c) is opened on the side wall of the small diameter cylinder (35b), while an outflow gap (A) between one end of the movable cylinder (45a) and the fixed valve seat (35d) is the movable cylinder ( It changes with the reciprocating movement in the axial direction of 45a).

  Further, a pressure receiving flange (45c) (an inlet (45b) for determining a pressure difference between the primary pressure P1 and the secondary pressure P2 is formed) projects from the upstream end of the movable cylinder (45a). The pressure receiving flange (45c) is biased in the valve opening direction by a spring (32). An opening (45d) is formed in the peripheral wall near the upstream end of the movable cylinder (45a).

In this case, when the outlet tap (96) connected to the water heater (98) on the downstream side of the joint body (3) is in the closed state, it acts on the movable valve (45) in the constant flow valve (2). Since the primary pressure P1 and the secondary pressure P2 are equal and both are in pressure balance, the spring (32) is maintained in the stretched state. Therefore, the movable cylinder (45a) is located on the most upstream side, and the outflow gap (A) is maintained in the maximum state. (The upper half of the center line in FIG. 8)
Next, when the tap tap (96) of the water heater (98) is opened and the secondary pressure P2 decreases, the primary pressure P1 upstream of the pressure receiving flange (45c) and the secondary pressure downstream of the pressure receiving flange (45c). The pressure difference of the pressure P2 acts on the pressure receiving flange (45c), whereby the movable valve (45) moves downstream while compressing the spring (32). Thereby, the outflow gap (A) between the movable cylinder (45a) and the fixed valve seat (35d) is maintained at a size corresponding to the pressure difference, and the rated flow rate Q determined by the pressure difference and the outflow gap (A). Of water is supplied to the tap tap (96) side. (The lower half of the center line in FIG. 8)
In this state, when the primary pressure P1 rises and the flow rate to the tap faucet (96) is likely to increase, the pressure difference (P1-P2) acting on the pressure receiving flange (45c) temporarily increases, and the movable valve ( 45) moves in the closing direction and the outflow gap (A) becomes smaller, and the increase in flow rate is suppressed. Further, as the passage resistance of the outflow gap (A) that has become smaller increases, the pressure P2 in the movable cylinder (45a) rises, and thereby the pressure difference (P1-P2) acting on the pressure receiving flange (45c). ) Returns to the initial value before the primary pressure rise and stabilizes.

Thereby, the water of the rated flow rate Q is stably supplied to the tapping tap (96) side without being affected by the fluctuation of the primary pressure P1.
The function of stabilizing the rated flow rate Q by the above action regardless of the fluctuation of the primary pressure P1 is hereinafter referred to as “governor function”.

However, in the above-mentioned conventional one, the magnitude of the rated flow rate Q that can be supplied downstream is determined depending on the strength of the spring (32), and thus is constant, such as the capacity of the water heater (98) and the like. Accordingly, the rated flow rate Q cannot be changed.
Therefore, when the constant flow rate valve (2) is applied to the water supply circuit of the water heater (98) and the rated flow rate Q is kept constant as described above, the following problems arise.

1. When using a constant flow valve (2) with a large rated flow Q in order to enable a large amount of hot water supply In this case, if the hot water user sets the temperature high using the remote controller of the hot water heater (98), the hot water heater (98) If the gas burner falls into a state where it does not reach the set temperature even if it burns at the maximum output, the hot water set at the above-mentioned remote controller or the like cannot be obtained because the water supply amount cannot be reduced.

2. When using a constant flow valve (2) with a small rated flow to enable high-temperature hot water supply In this case, even if hot water is supplied simultaneously in the shower or kitchen and a large amount of hot water is required, a hot water heater (98 ) Cannot be increased, and the flow rate of the shower or the like is insufficient.

Therefore, as an improvement plan for solving the above problem, it is conceivable to add a manual throttle valve to the constant flow valve (2) so that the rated flow rate Q can be adjusted.
Specifically, as shown in FIG. 9, an inlet (45b) is formed at one end of the movable valve (45), and a needle valve (a throttle valve) is provided at the inlet (45b) of the movable valve (45). 47) is configured so that it can be inserted and removed manually. Then, when switching to the large capacity state, the needle valve (47) is escaped from the inlet (45b) (in the imaginary line state in the figure), and the fluid passage area N in this part is the area of the inlet (45b). To match. On the other hand, when switching to the small capacity state, the needle valve (47) is inserted into the inflow port (45b) (in the state of the solid line in the figure), so that the inner circumference of the needle valve (47) and the inflow port (45b) A small passage area N is ensured between the two.
In this way, it is possible to adjust the rated flow rate of the constant flow valve (2) according to the capacity of the hot water heater (98), etc., thereby configuring a constant flow valve with a capacity adjustment function. Can do.

However, in the constant flow valve with the capacity adjustment function of the above improvement plan, in order to make it applicable to a large capacity water heater (98), the diameter of the inlet (45b) can be increased to secure a large flow rate. It is necessary to.
In this case, by inserting the needle valve (47) into the inlet (45b), the passage area N between the needle valve (47) and the inlet (45b) is reduced, and the rated flow rate Q is "small". The switching area N is expressed by the following equation.

That is, if the outer radius of the needle valve (47) is r ₂ and the inner radius of the inlet (45b) is r ₁ ,
Passage area N = π (r ₁ ² −r ₂ ² )
= Π (r ₁ + r ₂ ) (r ₁ −r ₂ )
In the above equation, (r ₁ −r ₂ ) is the size of the gap (K) between the outer periphery of the needle valve (47) and the inner periphery of the inflow port (45b). If you leave
Passage area N = π (r ₁ + r ₂ ) K... A
It becomes.

Therefore, if the diameter of the inlet (45b) is increased in order to be applicable to a high-capacity hot water heater, (r ₁ + r ₂ ) in the above equation a is increased.
Therefore, in the above formula a, if the passage area N when the rated flow rate Q is switched to “small” is constant, the dimension K of the gap (K) is equal to the inner radius r ₁ of the inlet (45b). The larger it is, the smaller it becomes. The size K of the gap (K) becomes smaller because the outer radius r ₂ of the needle valve (47) becomes significantly larger (r ₁ −r ₂ ) than the inner radius r ₁ of the inlet (45b) becomes larger. ) = K means that K becomes smaller.

And, in order to make the constant flow valve with the capacity adjustment function of the above-mentioned improved proposal applicable to a large capacity water heater, the outer radius r ₂ of the needle valve (47) becomes larger and the inner circumference of the inlet (45b) and the needle When the gap (K) between the valves (47) becomes small, the needle valve (47) is caught on the inner periphery of the inlet (45b) provided in the movable valve (45), and smooth flow control of the movable valve (45) is achieved. There was a problem that operation was hindered.
Japanese Patent Laid-Open No. 2001-355552 (FIG. 4)

  The present invention has been made in view of such points, and even when the needle valve (47) is inserted into the inlet (45b) and switched to a small capacity (small flow rate state), the movable valve (45) and the needle valve It is an object of the present invention to provide a constant flow valve with a capacity adjustment function that (47) does not get caught.

[1]
The technical means of the present invention for solving the above problems will be described with reference to FIG.
`` The primary pressure chamber (67) and the secondary pressure chamber (64) are arranged on the outer periphery of a movable cylinder (45a) having both ends opened in the axial direction and having an inlet (45b) that opens to the primary pressure chamber (67). A movable valve (45) around which a pressure receiving plate (45f) to be partitioned is provided;
A needle valve (47) that reciprocates in the axial direction between a small capacity state inserted into the inlet (45b) and a large capacity state escaped from the inlet (45b);
An opening (45d) provided on the peripheral wall of the movable cylinder (45a) to guide the secondary pressure to the secondary pressure chamber (64);
A capacity switching means (70) for moving the needle valve (47) between the small capacity state and the large capacity state;
A fixed valve seat (35d) facing the end of the movable cylinder (45a) opposite to the inlet (45b);
A secondary pressure spring (32) for biasing the movable valve (45) in the valve opening direction in which the movable cylinder (45a) is separated from the fixed valve seat (35d);
A primary pressure spring (53) for biasing the movable valve (45) in a valve closing direction in which the movable cylinder (45a) approaches the fixed valve seat (35d),
The primary pressure spring (53) is interposed between the needle valve (47) inserted into the inflow port (45b) and the movable valve (45) in a compressed state ”.
According to the above technical means, since the primary pressure spring (53) is provided, the needle valve (47) can be narrowed, and thereby the gap between the inner periphery of the inlet (45b) and the needle valve (47) (K ) Can be increased, and the above-described problems can be solved.

Hereinafter, the operation of the present invention will be described in more detail with reference to FIGS.
The primary pressure upstream of the movable valve (45) is such that the movable valve (45) is closed (the movable cylinder (45a) is moved closer to the fixed valve seat (35d) and the outflow gap (A) between them is reduced. And the urging force of the primary pressure spring (53) that urges in the direction of the pressure acting on the upstream surface (upper surface in FIG. 1) of the pressure receiving plate (45f). In addition, the secondary pressure downstream of the inlet (45b) is caused by the opening direction of the movable valve (45) by moving the movable valve (45) away from the fixed valve seat (35d). Along with the urging force of the secondary pressure spring (32) urging in the direction in which the pressure is increased, it acts on the downstream surface (lower surface in FIG. 1) of the pressure receiving plate (45f).

  In this state, when a fluid flow is generated by opening the downstream faucet or the like, the upstream side of the movable valve (45) → the inlet (45b) of the movable valve (45) → the inside of the movable cylinder (45a) → the movable cylinder (45a ) And the fixed valve seat (35d), the fluid flows through a path connecting from the outflow gap (A) to the downstream side of the fixed valve seat (35d). The movable valve (45) is stabilized at a position where the primary pressure P1 and the secondary pressure P2 applied to the upstream surface and the downstream surface of the pressure receiving plate (45f) are balanced, and the flow rate is constant by the outflow gap (A) at this time. Kept.

Next, the relationship between the operation for switching the rated flow rate Q between the large capacity state and the small capacity state and the flow rate adjustment operation of the constant flow valve (2) associated therewith will be described.
When the capacity switching means (70) is activated, the needle valve (47) escapes from the inlet (45b) of the movable cylinder (45a) when the large capacity state shown in FIG. Corresponds to the area of the inlet (45b). As a result, the passage area N is maintained in a large state as compared with the small capacity state described later, and in this state, the constant flow valve maintains the large flow rate Q _max with the constant governor function.

On the contrary, when the capacity switching means (70) is switched to the small capacity state shown in (a) of FIG. 1, the tip of the needle valve (47) is connected to the inlet (45b) of the movable cylinder (45a). And a small gap (K) is secured between the needle valve (47) and the inner periphery of the inflow port (45b), and the passage area N is reduced. In this state, the flow rate is maintained at a constant small flow rate Q _min by the governor function of the constant flow valve.

Next, two principles will be described in which the flow rate decreases as the large capacity state (flow rate Q _max ) is switched to the small capacity state (flow rate Q _min ).
1. Similar to the improvement of FIG. 9, the flow rate is reduced by the needle valve (47) restricting the inlet (45b) of the movable valve (45).
When the large capacity state is switched to the small capacity state, the tip of the needle valve (47) enters the inlet (45b), the inlet (45b) is throttled, and the flow rate is reduced, as in the above-described improvement plan. descend. As a result, the flow rate is decreased by ΔL1 from the initial large flow rate Q _max shown in FIG. 2 to the virtual throttle state L, which is the same as the small capacity state of the improved plan.

2. Flow rate drop due to compression of primary pressure spring (53).
The effective pressure receiving area of the movable valve (45) is S, the spring constant of the primary pressure spring (53) is k1, the compression amount of the primary pressure spring (53) in the large capacity state is B1, and the spring of the secondary pressure spring (32) Assuming that the constant is k2 and the compression amount of the secondary pressure spring (32) in the large capacity state is B2, the formula of the balance between the primary pressure side and the secondary pressure side force of the movable valve (45) in the large capacity state is
S x P1 + k1 x B1 = S x P2 + k2 x B2 ... b
On the other hand, if the compression amount of the primary pressure spring (53) becomes (B1 + ΔB1) when switching to the small capacity state (the state of (A) in FIG. 1), this is substituted into equation b,
S × P1 + k1 × (B1 + ΔB1) = S × P2 + k2 × (B2 + ΔB2) c
To get the formula

Therefore, when switching to the small capacity state, the movable valve (45) moves in the closing direction by ΔB2, the outflow gap (A) further decreases, and the flow rate decreases by ΔL2.
Therefore, from the stop state L shown in FIG. 2 (a state where the effect of the "1" occurs), a flow rate thereof is reduced by further ΔL2 minutes to a final aperture state Q _min.

  As described above, according to the present invention, in addition to the flow restriction effect of “1” produced by the constant flow valve with the capacity adjustment function of the above-described improved proposal, the flow restriction effect of “2” is further generated. In the present invention, the flow rate adjustment range is increased by ΔL 2 compared to the improvement plan.

Therefore, in the present invention, even when the flow rate when switched to the small capacity state is increased by the above-described ΔL2, the same flow rate adjustment performance as that of the improved constant flow valve with the flow rate adjustment function (Q _max ~ in FIG. 2). A constant flow valve having a capability of holding a flow rate adjustment range in the throttle state L).

That is, the diameter of the inlet (45b) is set to be the same as that of the improvement plan so that the same large flow rate Q _max as that of the improvement plan (flow rate in the large capacity state of (b) in FIG. 1) can be obtained, and Even if the passage area N is increased by increasing the small flow rate Q _min (the flow rate in the small capacity state of FIG. 1 (b)) to the throttle state L at the same level as the improved plan, the same flow rate adjustment as the improved plan The range (Q _max -L) can be set.

In other words, in order to increase the passage area N while setting the inner radius r ₁ of the inflow port (45b) to the same size as that of the improved proposal, the needle valve (47) is narrowed (r ₂ is reduced) and the gap size is increased. K can be increased.

  Thus, in the present invention, when the same flow rate adjustment performance as that of the improved proposal is set, the dimension K of the gap (K) in the small capacity state can be increased. Therefore, in the small capacity state, the needle valve (47) Is not caught on the periphery of the inlet (45b) of the movable valve (45). Therefore, since the movable valve (45) operates smoothly, the governor function of the constant flow valve that makes the flow rate constant can be obtained with certainty.

[2]
In item 2 above,
“The capability switching means (70) includes a cam mechanism that reciprocally moves the needle valve (47) in the axial direction in conjunction with rotation of the input shaft”. When reversed, the needle valve (47) moves toward and away from the inlet (45b) of the movable valve (45) to adjust the flow rate as described above.

[3]
In item 2 above,
“The input shaft is rotated by the rotation of the manual switching operation section (73)”.

Since the present invention has the above configuration, the present invention has the following specific effects.
As described above, the size K of the gap (K) between the inner periphery of the inlet (45b) and the needle valve (47) in the small capacity state can be increased as compared with the improved proposal shown in FIG. It is possible to provide a flow rate adjusting valve with a capability adjusting function in which the needle valve (47) is not caught on the periphery of the inlet (45b) of the movable valve (45) in the capability state.

Next, the above-described embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 3 is a cross-sectional view of the constant flow valve (2) with an ability adjustment function according to the embodiment of the present invention, and shows a water flow stop state. FIG. 4 is an enlarged view of a correlation part of the needle valve (47) and the movable valve (45) in FIG.

  The right side of the center line (shown by the imaginary line) of the needle valve (47) and the movable valve (45) in FIGS. 3 and 4 shows the case where water flow is stopped in a state where the capacity is switched to the large capacity. On the other hand, the left side of the center line shows a case where water flow is stopped in a state where the small capacity is switched.

  When the water flow is stopped, the movable valve (45) is separated from the fixed valve seat (35d), and the outflow gap (A) between the movable valve (45) and the fixed valve seat (35d) is described later. The size is kept larger than when the water is passed.

  As shown in FIG. 3, the constant flow valve (2) with a capacity adjustment function according to the embodiment of the present invention is downstream of the bending point of the L-shaped flow path (4) provided through the body case (40). A valve mechanism part (41) disposed in the part, a capacity switching means (70) having a switching operation part (73) for setting and changing the rated flow rate, and a flow meter located upstream of the valve mechanism part (41) (89).

[Valve mechanism (41)]
As shown in FIGS. 3 and 4, the valve mechanism (41) is a movable cylinder slidably inserted into a flange (35h) of a cylindrical valve box (35) inserted into the body case (40). A movable valve (45) having (45a), and a needle valve (47) loosely inserted into an inlet (45b) of the movable valve (45).

  A pressure receiving plate (45f) for receiving the pressure in the flow path (4) is fitted into an annular groove (45e) formed on the outer periphery of the upper end of the movable cylinder (45a) constituting the movable valve (45). The sum of the surface areas of the lower end (45f2) and the upper end (45f1) of the outer periphery of the pressure receiving plate (45f) is an effective area for receiving pressure.

  The movable cylinder (45a) is provided with an annular spring receiving piece (45a1) projecting below the annular groove (45e), and between the annular spring receiving piece (45a1) and the valve box (35). Between the flange (35h), a secondary pressure spring (32) for biasing the movable valve (45) toward the upstream primary pressure chamber (67) is interposed in a compressed state. The side wall of the movable cylinder (45a) passes through the secondary pressure chamber (64) inside the pressure receiving plate (45f) and an opening (45d) that communicates the inside of the movable cylinder (45a).

Further, the upper end of the valve fixing cylinder (34) assembled from the downstream end outlet (39) of the flow path (4) penetrating the main body case (40) is a valve box (35) for accommodating the movable valve (45). ) From below. A fixed valve seat (35d) formed integrally with the valve box (35) and extending forward and backward with respect to the paper surface is provided on the inner wall of the valve box (35).
An annular seal member (38) for guiding the movable cylinder (45a) while ensuring water tightness is disposed on the inner peripheral edge of the flange (35h).

  The upper end portion (45f1) of the pressure receiving plate (45f) externally fitted to the upper end of the movable cylinder (45a) is pressed downward (secondary side) at one end of the primary pressure spring (53). The other end of the primary pressure spring (53) is in contact with a spring receiver (54) that engages with the outer peripheral step (47a) of the needle valve (47).

[About ability switching means (70)]
As shown in FIGS. 3 and 7, a slider (56) is externally fitted to the input side end of the needle valve (47) in a non-rotating state by a coupling pin (27). The cam groove (57) formed in the side wall of the slider (56) is engaged with a cam flange (62) spirally provided on the outer periphery of the cam cylinder (61). Therefore, when the cam cylinder (61) is rotated, the slider (56) and the needle valve (47) are brought together by the cam groove (57) of the slider (56) and the cam flange (62) of the cam flange (62). Reciprocates in the axial direction.

  The central shaft (72) fitted in a non-rotating state at the center of the cam cylinder (61) is connected to an input shaft (74) fixed to a manual operation knob (73) for capacity adjustment. 75) are connected coaxially. The connecting pin (75) has a rotation angle so that the connection pin (75) can be rotated between a pair of stopper projections (83) and (84) standing up from a cam case (81) that houses the cam cylinder (61). The range in which the capacity can be adjusted by the constant flow valve with the capacity adjusting function according to the present embodiment can be set in the range shown in FIGS.

[Actual behavior]
Next, the actual operation of the constant flow valve with the capability adjusting function will be described.
As shown in FIG. 3 showing the water flow stop state, the constant flow valve with a capacity adjustment function according to the present embodiment is used, for example, in a water supply circuit (97) to a water heater (98). The

  For example, when it is necessary to take out a large amount of low-temperature hot water by burning a large-capacity water heater (98) with the maximum capacity, the needle valve (47) in FIG. ) Is moved to the high-capacity state (high-capacity state in which the needle valve (47) is raised) appearing on the right side of the center line. Specifically, by rotating the cam cylinder (61) by operating the operation knob (73) appearing in FIG. 3, the cam flange (62) on the outer periphery of the cam cylinder (61) is moved to the cam groove of the slider (56). (57), thereby moving the slider (56) toward the rear end of the needle valve (47) to maximize the opening of the inlet (45b) (the needle valve (47) Set to the last retreat position).

  In this case, the primary pressure P1 as the pressure on the upstream side of the inflow port (45b) cooperates with the urging force of the primary pressure spring (53), and the upper end portion (45f1) and the lower end portion ( 45f2) is pressed from above. A secondary pressure P2 downstream of the inflow port (45b) (corresponding to the primary pressure P1 when the water flow is stopped in FIGS. 3 and 4) is an opening (45d) provided in the movable cylinder (45a). ) To the secondary pressure chamber (64) on the lower surface side of the upper end portion (45f1) and the lower end portion (45f2) of the pressure receiving plate (45f). As a result, the urging force of the secondary pressure spring (32) that urges the movable valve (45) in the valve opening direction and the secondary pressure P2 cooperate to form the upper end (45f1), the lower end (45f2), etc. It acts on the lower surface of the.

Next, the operation of each part when the stop state shown in FIGS. 3 and 4 is changed to the water flow state shown in FIGS.
In the state shown in FIG. 6 (high capacity state and water flow stopped state), when the water supply state is opened by opening the outlet tap (96) on the downstream side of the water heater (98), the upstream end inlet (90) connected to the water supply → Primary pressure chamber (67) → Inlet port (45b) of movable valve (45) → Inside movable cylinder (45a) → Route through the path connecting the movable cylinder (45a) and outflow gap (A) between fixed valve seat (35d) Watered. In addition, the pressure difference (P1-P2) between the primary pressure P1 on the upstream side of the pressure receiving plate (45f) and the secondary pressure P2 on the downstream side of the pressure receiving plate (45f) is generated with the opening of the tap (96). The movable valve (45) approaches the fixed valve seat (35d) against the urging force of the secondary pressure spring (32), as shown in FIG. The outflow gap (A) between the movable cylinder (45a) and the fixed valve seat (35d) is maintained at a predetermined size, and water supply to the downstream side is continued. At this time, even if the primary pressure P1 upstream of the constant flow valve (2) fluctuates, the water supply amount to the water heater (98) side is kept constant at Q _max by the governor function described above.

Next, the operation for switching the flow rate from the large capacity state (large flow state) shown in FIG. 6 to the small capacity state (small flow state) shown in FIG. To do.
As shown in FIG. 6, in the large capacity state where the needle valve (47) is raised, when the operation knob (73) appearing in FIG. 3 is rotated to switch to the small capacity state, the needle valve (47) is Advance. Specifically, the needle valve (47) is lowered from the raised position in FIG. 6 to the position shown in FIG.

  When water flow occurs in the small capacity switching state, as shown in FIG. 5, the movable valve (45) is kept close to the fixed valve seat (35d), and the primary pressure chamber (67) → needle Gap between the outer circumference of the valve (47) and the inner circumference of the inlet (45b) (K) → Outlet gap (A) between the movable cylinder (45a) and the fixed valve seat (35d) → Downstream end outlet (39) Water is supplied.

  When the large capacity state shown in FIG. 6 is switched to the small capacity state shown in FIG. 5, the flow restricting effects “1” and “2” described in the operation of the present invention described above are produced. That is, in addition to the flow restricting effect of “1” produced by the constant flow valve with the ability adjusting function of the improved plan of FIG. 9, the flow restricting effect of “2” is further generated. As a result, in the constant flow valve with a flow rate adjustment function of the present application, the flow rate adjustment range is increased by ΔL2 shown in FIG.

Therefore, in the constant flow valve with the capacity adjustment function of the present application, even when the flow rate when the small capacity state is switched is increased by the above-described ΔL2, the same flow control as the constant flow valve with the flow adjustment function of FIG. It can be a constant flow valve with performance (the flow rate adjustment range is the range of Q _max to throttle state L in FIG. 2).

That is, the diameter of the inlet (45b) is set to be the same as that of the improvement plan so that the same large flow rate Q _max (the flow rate in the large capacity state in FIG. 6) can be secured, and the small flow rate Q _min ( The passage area N (the inlet (45b) inner circumference and the needle valve (47) in the small capacity state shown in FIG. 5) is increased by increasing the flow rate in the small capacity state in FIG. Even if the area between the two is increased, it is possible to secure the same flow rate adjustment range (“Q _max -L” shown in FIG. 2) as the improvement plan.

In other words, in order to increase the passage area N while setting the inner radius r ₁ of the inflow port (45b) to the same size as that of the improved proposal, the needle valve (47) is narrowed (r ₂ is reduced) and the gap size is increased. K can be increased.

  Thus, in the constant flow valve with a flow rate adjusting function of the present invention, since the dimension K of the gap (K) in the state of switching to the small capacity can be increased as compared with the improved one, in the small capacity state, The needle valve (47) is not caught on the periphery of the inlet (45b) of the movable valve (45). Therefore, since the movable valve (45) operates smoothly, the governor function of the constant flow valve that makes the flow rate constant can be obtained with certainty. Therefore, it is possible to provide a flow rate adjusting valve with a capability adjusting function in which the needle valve (47) is not caught on the periphery of the inlet (45b) of the movable valve (45) in the small capacity state.

In the above embodiment, the case where the constant flow valve with the capacity adjustment function of the present invention is applied to the water supply circuit to the water heater (98) is described as an example, but the present invention is not limited to the gas circuit or the gas circuit. Needless to say, the present invention can be applied to various fluid circuits.
In the above embodiment, the cam cylinder (61) is manually rotated. However, the cam cylinder (61) may be rotated by a motor.

Action explanatory diagram of the present invention A graph for explaining the flow rate difference between the small capacity state (A) and the large capacity state (B) in FIG. Sectional drawing at the time of the water flow stop of the constant flow valve with a capacity adjustment function according to the embodiment of the present invention 3 is an enlarged cross-sectional view of the main part of FIG. 3 (correlation part of the needle valve (47) and the movable valve (45)). Sectional drawing of the principal part at the time of water-flowing in the state which switched the constant flow valve with a capability adjustment function which concerns on embodiment of this invention to the small capability state Sectional drawing of the principal part at the time of water-flowing in the state which switched the constant flow valve with a capability adjustment function which concerns on embodiment of this invention to a large capacity state Top view of slider (56) Illustration of conventional example Illustration of improvement plan

Explanation of symbols

(32) ・ ・ ・ Secondary pressure spring
(35d) ・ ・ ・ Fixed valve seat
(45) ・ ・ ・ Moving valve
(45a) ・ ・ ・ Movable cylinder
(45b) ・ ・ ・ Inlet
(45f) ・ ・ ・ Pressure plate
(47) ... Needle valve
(53) ... Primary pressure spring
(64) ・ ・ ・ Secondary pressure chamber
(67) ... Primary pressure chamber
(70) ・ ・ ・ Capability switching means
(73) ... Switching operation part

Claims (3)

The primary pressure chamber (67) and the secondary pressure chamber (64) are defined on the outer periphery of a movable cylinder (45a) having both ends opened in the axial direction and having an inlet (45b) that opens to the primary pressure chamber (67). A movable valve (45) around which a pressure receiving plate (45f) is provided;
A needle valve (47) that reciprocates in the axial direction between a small capacity state inserted into the inlet (45b) and a large capacity state escaped from the inlet (45b);
An opening (45d) provided on the peripheral wall of the movable cylinder (45a) to guide the secondary pressure to the secondary pressure chamber (64);
A capacity switching means (70) for moving the needle valve (47) between the small capacity state and the large capacity state;
A fixed valve seat (35d) facing the end opposite to the inlet (45b) of the movable cylinder (45a),
A secondary pressure spring (32) for biasing the movable valve (45) in the valve opening direction in which the movable cylinder (45a) is separated from the fixed valve seat (35d);
A primary pressure spring (53) for biasing the movable valve (45) in a valve closing direction in which the movable cylinder (45a) approaches the fixed valve seat (35d),
The primary pressure spring (53) is a constant flow valve with a capacity adjustment function that is interposed between the needle valve (47) inserted into the inlet (45b) and the movable valve (45) in a compressed state. . In the constant flow valve with a capacity adjustment function according to claim 1,
The capacity switching means (70) is a constant flow valve provided with a cam mechanism for reciprocating the needle valve (47) in the axial direction in conjunction with rotation of the input shaft. In the constant flow valve with capacity adjustment function according to claim 2,
The input shaft is a constant flow valve rotated by rotation of a manual switching operation unit (73).

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