JP2007100813A - Differential pressure-regulating valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a compact differential pressure-regulating valve easily and at low cost. <P>SOLUTION: The differential pressure-regulating valve 1 is equipped with a plug 3 in which a valve element forming part 21 having a function of a valve element and a casing part 22 having a function of a case are integrally formed, and has a structure for opening/closing a valve part by the plug 3 proceeding/receding with respect to a housing 2. Therefore, the number of components is reduced, the structure is simplified, and a low cost can be substantialized. Further, a coil spring 28 for closing the valve part is arranged on the inside of the housing 2, and the plug 3 is structured in a substantially complementary shape to the housing 2 mounted so as to cover the housing 2. Thereby, the differential pressure regulating valve 1 is made compact in the axial direction. Especially upon closing of the valve, the plug 3 is in a substantially fitted state with the housing 2, while an extending part 26 supporting the coil spring 28 is structured so as not to protrude to the outside of the housing 2, and therefore, the valve 1 becomes very compact in size. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a differential pressure valve, and more particularly to a differential pressure valve suitable for use in a variable capacity compressor of an automotive air conditioner.

  The automotive air conditioner includes a refrigerant compression compressor that is driven by a vehicle engine as a power source. In this compressor, since the rotational speed of the vehicle engine greatly varies depending on the traveling state of the vehicle, it is necessary to maintain the discharge capacity at a set capacity regardless of the rotational speed. Therefore, a variable capacity compressor is used as a compressor of an automobile air conditioner.

  This variable capacity compressor is connected to the vehicle engine via an electromagnetic clutch, for example. When the automobile air conditioner is not in use, the electromagnetic clutch is disconnected so that the power of the vehicle engine is not transmitted to the variable capacity compressor. During use of the automobile air conditioner, the electromagnetic clutch is connected and variable. The capacity compressor is driven by the vehicle engine.

  However, providing such an electromagnetic clutch increases the weight of the vehicle and increases the manufacturing cost. Furthermore, large electric power is consumed when the electromagnetic clutch is operated. For this reason, so-called clutchless variable displacement compressors have been adopted in which the mounting of an electromagnetic clutch is eliminated and the vehicle engine is directly connected. Since this clutchless type variable displacement compressor is always driven to rotate by the vehicle engine, it is controlled to an operation state in which the discharge capacity is minimized, especially when the automobile air conditioner is not activated. However, even if the variable capacity compressor is controlled to the operation state with the minimum capacity, the discharge capacity is not zero. Therefore, the variable capacity compressor continues to discharge the refrigerant of the minimum capacity. For this reason, in the evaporator in which the refrigerant is continuously circulated in the refrigeration cycle and the refrigerant cooled from the expansion valve is fed, frost may adhere to the surface or freeze.

  Therefore, in a clutchless type variable capacity compressor, a differential pressure valve is provided in a passage through which refrigerant is discharged from the discharge chamber (see, for example, Patent Document 1). This differential pressure valve (expressed as “check valve” in Cited Document 1) has a valve body disposed downstream of the refrigerant flow with respect to the valve seat, and the valve body is urged in the valve closing direction by a spring. When the differential pressure across the valve reaches a predetermined value or more, the valve is opened and the refrigerant is discharged. That is, when the force acting in the valve opening direction due to the differential pressure acting on the valve portion of the differential pressure valve exceeds the load of the spring acting in the valve closing direction, the valve portion starts to open.

By disposing such a differential pressure valve in the variable capacity compressor, when the vehicle air conditioner is stopped and the variable capacity compressor is in the minimum capacity operation state, the valve portion is closed so that the refrigerant is not discharged, When the automotive air conditioner is activated, the valve is fully opened.
JP 2000-345967 A

  However, such a differential pressure valve has a refrigerant inlet port that communicates with the discharge port on one end side, a valve seat member provided with a valve seat on the other end side opening portion, and a case fitted to the valve seat member And a valve body that is slidable in the axial direction in the case, and a spring that biases the valve body in the direction of the valve seat member in the case, and has a large number of parts and a complicated structure. . For this reason, there exists a problem that manufacturing cost increases.

  In addition, since the valve body that operates in the axial direction and the spring that biases the valve body in the axial direction are arranged in series in the case, the case is enlarged in the axial direction. Further, since the case is arranged in series with the valve seat member in the axial direction, the entire differential pressure valve becomes larger in the axial direction, resulting in a problem of installation space in the variable capacity compressor.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a differential pressure valve that can be realized simply and at low cost and can be configured compactly.

  In the present invention, in order to solve the above problem, a differential pressure valve that opens and closes based on the differential pressure across the valve portion has a fluid inlet on one end and a valve seat formed near the outlet on the other end. A housing that is attached to the housing so as to cover the other end, and that opens and closes the valve portion by attaching and detaching to the valve seat, and opening and closing the valve portion along the outer peripheral surface of the housing A guide portion that slides in a direction, an opening that is formed between the valve forming portion and the guide portion and leads out the fluid that has passed through the valve portion, and an extending portion that extends into the housing. There is provided a differential pressure valve characterized by comprising: a plug having a plug; and a biasing means disposed in the housing and biasing the plug in the valve closing direction via the extension portion.

  In such a differential pressure valve, a plug having a function of a valve body and a case is attached to a housing provided with a valve seat so as to cover an end portion on the valve seat side, and operates in the opening / closing direction of the valve portion. . Further, an urging means is arranged inside the housing and urges the plug to be attracted to the housing side. In particular, when the valve is closed, the plug operates on the side close to the housing in the valve portion, so the size of the differential pressure valve in the axial direction becomes small.

  According to the differential pressure valve of the present invention, the plug has the functions of the valve body and the case, the number of parts is reduced, and the structure is simplified, so that it can be realized at low cost. Further, since the urging means is disposed inside the housing and the plug is attached so as to cover the end of the housing on the valve seat side, the differential pressure valve becomes compact in the axial direction.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[First Embodiment]
First, a first embodiment of the present invention will be described. In the present embodiment, the differential pressure valve of the present invention is applied to a clutchless variable displacement compressor of an automotive air conditioner. FIG. 1 is a front view illustrating the configuration of the differential pressure valve according to the first embodiment. FIG. 2 is a cross-sectional view taken along the line AA of FIG. Further, FIG. 3 is a cross-sectional view taken along the line BB in FIG.

  As shown in FIG. 1, the differential pressure valve 1 is constructed by coaxially assembling a stepped cylindrical housing 2 made of brass and a bottomed cylindrical plug 3 made of a resin material. The differential pressure valve 1 is disposed in a refrigerant passage connected to a discharge chamber of the variable capacity compressor.

  As shown in FIGS. 2 and 3, the housing 2 is formed with an inlet 4 for communicating with the discharge chamber of the variable capacity compressor at one end thereof for introducing the discharged refrigerant, and downstream of the discharged refrigerant at the other end. A lead-out port 5 for leading to the side is formed. The housing 2 is configured such that the shape of the outer peripheral portion and the inner peripheral portion thereof decreases stepwise in the axial direction from the inlet 4 toward the outlet 5.

  That is, the housing 2 is provided with a flange portion 7 extending outwardly on the introduction port 4 side of the main body portion 6 at the center in the axial direction, and on the lead-out port 5 side, the reduced diameter portion 8 whose outer diameter is gradually reduced. And the valve seat formation part 9 is provided. This flange portion 7 is fixed to a refrigerant passage connected to a discharge chamber of a variable capacity compressor (not shown). Further, the valve seat 10 is constituted by the front end surface of the valve seat forming portion 9. Furthermore, a locking projection 11 for locking the movement of the plug 3 in the axial direction is provided at the end of the outer peripheral surface of the main body 6 on the reduced diameter portion 8 side.

  Further, the internal passage of the housing 2 is reduced by one step at a position slightly closer to the outlet 5 than the boundary between the main body 6 and the diameter-reduced portion 8, and forms a valve hole 12 connected to the outlet 5. ing. A spring seat 13 is configured by a portion of the step portion of the internal passage facing the inlet 4 side.

  The plug 3 has a stepped cylindrical shape that is substantially complementary to the outer peripheral surface excluding the flange portion 7 of the housing 2 and is attached to the housing 2 so as to cover the outer peripheral surface from the outside. The plug 3 includes a bottomed cylindrical valve body forming portion 21 integrally formed by injection molding of a resin material, and a casing portion 22 having an enlarged diameter from the valve body forming portion 21 toward the opening end. Become.

  The valve body forming portion 21 includes a valve forming portion 23 that is attached to and detached from the valve seat 10 to open and close the valve portion by a portion facing the valve seat 10 at the bottom, that is, a ring-shaped region set at the bottom. Yes. The inner peripheral surface of the valve body forming portion 21 is a guide portion 24 that slides in the axial direction along the outer peripheral surface of the reduced diameter portion 8 of the housing 2.

  Also, four openings 25 are provided at equal intervals in the circumferential direction at the corners of the bottom of the valve body forming portion 21 (see FIG. 1). The opening 25 opens from the peripheral edge of the bottom of the valve body forming portion 21 to the side, and guides the refrigerant that has passed through the valve to the downstream side.

  Furthermore, a shaft-like extending portion 26 extending into the housing 2 is provided at the center of the bottom of the valve body forming portion 21, and a ring-shaped spring receiver 27 is crimped and joined to the tip thereof. Yes. Between the spring receiver 27 and the spring seat 13, a conical coil spring 28 (corresponding to "biasing means") that biases the plug 3 toward the housing 2 side, that is, the valve closing direction, is interposed. Has been. As shown in the figure, the length of the extending portion 26 is set so that it is located in the vicinity of the introduction port 4 of the housing 2 and does not protrude outward from the housing 2 when the valve portion is in the closed state. Has been.

  The casing portion 22 is connected to the guide portion 24 of the valve body forming portion 21 and extends outward in the radial direction, and extends from the outer peripheral end in the axial direction so as to cover the main body portion 6. It consists of a cylindrical body having a L-shaped cross section provided with a restricting portion 30.

  The base portion 29 faces the end surface of the main body portion 6 on the outlet port 5 side, and a damper chamber 31 that prevents slight vibration in the axial direction of the plug 3 is constituted by a space formed between these facing surfaces. Has been. A small pressure relief hole 32 is provided at the peripheral edge of the base portion 29 to allow the damper chamber 31 to communicate with the outside.

  Further, a locking protrusion 33 protruding inward in the radial direction is provided at the opening end of the restricting portion 30 and faces the locking protrusion 11 of the housing 2 in the axial direction. When the plug 3 operates in the valve opening direction, the movement of the plug 3 is restricted by the lock protrusion 11 being locked to the lock protrusion 11. That is, the locking projection 33 and the locking projection 11 constitute a regulating structure that locks the sliding of the plug 3 when the valve portion is fully opened and regulates the lift amount of the valve forming portion 23 from the valve seat 10. Yes.

Next, the operation of the differential pressure valve of the present embodiment will be described. FIG. 4 is a cross-sectional view showing the configuration of the differential pressure valve in the opened state, and corresponds to FIG. 2 (representing the closed state).
When the variable capacity compressor is in the minimum capacity operation state and the discharge pressure is small, such as when the automotive air conditioner is stopped, the differential pressure valve 1 is controlled by the valve forming portion 23 by the load of the coil spring 28. The user sits on the seat 10 and enters the valve closing state shown in FIG.

  When the automotive air conditioner is started or when the variable capacity compressor shifts from the minimum capacity operation to the variable capacity operation, the force in the valve opening direction due to the differential pressure across the differential pressure valve 1 is changed in the valve closing direction due to the load of the coil spring 28. When the force is exceeded, the valve begins to open. At this time, the valve forming portion 23 lifts from the valve seat 10 and eventually becomes the fully opened state shown in FIG. The valve opening degree of the valve portion when fully opened is set in advance by the restriction structure formed by the locking projection 33 and the locking projection 11 described above.

  As described above, the differential pressure valve 1 includes the plug 3 in which the valve body forming portion 21 having a valve body function and the casing portion 22 having a case function are integrally formed, and the plug 3 is attached to the housing 2. In contrast, the valve portion is opened and closed by moving forward and backward. For this reason, since the number of parts is reduced and the structure is simplified, it can be realized at low cost.

  In addition, since the coil spring 28 for closing the valve portion is disposed inside the housing 2 and the plug 3 is configured so as to be substantially complementary to the housing 2 so as to cover the housing 2, the differential pressure valve 1 is It becomes compact in the axial direction. In particular, when the valve is closed, the plug 3 is substantially fitted with the housing 2, while the extending portion 26 that supports the coil spring 28 is configured not to protrude outside the housing 2. Becomes very compact. For this reason, there exists an advantage that it is convenient also in the installation to the variable capacity compressor of the automotive air conditioner.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. The differential pressure valve according to the present embodiment is substantially the same as the configuration of the differential pressure valve of the first embodiment except that the structure of the plug is different. Therefore, the same components are denoted by the same reference numerals. The description is omitted. FIG. 5 is a front view illustrating the configuration of the differential pressure valve according to the second embodiment. FIG. 6 is a cross-sectional view taken along the line CC in FIG. 5 and shows a closed state of the differential pressure valve. Further, FIG. 7 is a cross-sectional view showing the configuration of the differential pressure valve in the open state, and corresponds to FIG.

  As shown in FIG. 5, the differential pressure valve 201 is configured by coaxially assembling a stepped cylindrical housing 2 made of brass and a bottomed cylindrical plug 203 made of a resin material.

  As shown in FIGS. 6 and 7, the plug 203 is provided with four openings 225 at equal intervals in the circumferential direction in the vicinity of the periphery of the bottom of the valve body forming portion 221. The opening 225 does not open in the side part of the valve body forming part 221 and is formed so as to penetrate the bottom part in the axial direction (that is, the opening / closing direction of the valve part).

  When the variable capacity compressor is in the minimum capacity operation state and the discharge pressure is small, such as when the automotive air conditioner is stopped, the differential pressure valve 201 is controlled by the valve forming portion 23 by the load of the coil spring 28. It sits on the valve seat 10 and the valve closing state shown in FIG.

  When the automotive air conditioner is started or when the variable capacity compressor shifts from the minimum capacity operation to the variable capacity operation, the force in the valve opening direction due to the differential pressure across the differential pressure valve 201 is changed in the valve closing direction due to the load of the coil spring 28 When the force is exceeded, the valve forming portion 23 lifts from the valve seat 10 and eventually shifts to the fully open state shown in FIG. At this time, the refrigerant introduced from the introduction port 4 is led out to the downstream side in the axial direction through the opening 225.

  Also in the differential pressure valve 201 of the present embodiment, the plug 203 has the functions of a valve body and a case, the number of parts is reduced, and the structure is simplified, so that it can be realized at low cost. Further, since the coil spring 28 is disposed inside the housing 2 and the plug 203 is attached so as to cover the housing 2, the coil spring 28 is compact in the axial direction.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. The differential pressure valve according to the present embodiment is substantially the same as the configuration of the differential pressure valve of the first embodiment except that the structure of the plug is mainly different. A description thereof will be omitted, for example. FIG. 8 is a front view illustrating the configuration of the differential pressure valve according to the third embodiment. FIG. 9 is a cross-sectional view taken along the line DD in FIG. 8 and shows a closed state of the differential pressure valve. Further, FIG. 10 is a cross-sectional view showing the configuration of the differential pressure valve in the valve open state, and corresponds to FIG.

  As shown in FIG. 8, the differential pressure valve 301 is formed by coaxially assembling a stepped cylindrical housing 302 made of brass and a bottomed cylindrical plug 303 made of a resin material.

  As shown in FIGS. 9 and 10, the housing 302 has substantially the same configuration as the housing 2 of the first embodiment, but the main body 306, The reduced diameter portion 308 and the valve seat forming portion 309 are configured to be slightly longer in the axial direction.

  The valve body forming portion 321 of the plug 303 includes a valve forming portion 23 that is attached to and detached from the valve seat 10 to open and close the valve portion by a ring-shaped region facing the valve seat 10 at the bottom. From the vicinity of the outer peripheral portion of the valve forming portion 23, a pressure receiving holding portion 310 is extended so as to be extrapolated to the valve seat forming portion 309. Six openings 325 are provided at equal intervals in the circumferential direction at the corners of the bottom of the valve body forming portion 321 (see FIG. 8). The opening 325 opens from the periphery of the bottom of the valve body forming portion 321 to the side, and allows the refrigerant that has passed through the valve to be led to the downstream side.

FIG. 11 is a cross-sectional view illustrating the configuration of the plug. 12 is a view taken in the direction of arrow E in FIG. Further, FIG. 13 is a view in the direction of arrow F in FIG.
As shown in these drawings, the pressure receiving holding portion 310 extends from the bottom portion of the plug 303 like a wall portion surrounding the proximal end portion of the extending portion 26. On the side surface of the pressure receiving holding portion 310, cutout portions 311 cut out as tapered concave portions are provided at equal intervals (every 30 degrees) in the circumferential direction. As will be described later, the notch 311 forms a throttle channel for the refrigerant when the valve is opened.

  That is, as shown in FIG. 10, the pressure receiving diameter when the valve is closed (the diameter of the region receiving the refrigerant pressure from the upstream side) is φA, and the pressure receiving diameter changes to φB (> φA) when the valve is opened. To do. Therefore, when the valve portion begins to open, the pressure receiving diameter increases and the load in the valve opening direction received by the plug 303 increases. Further, when the valve portion starts to open, a trapezoidal throttle channel is formed between the above-described notch portion 311 and the valve seat forming portion 309. Therefore, as shown by the arrows in the figure, the refrigerant from the upstream side Is led to the downstream side through this throttle channel. At this time, the throttle passage gradually increases as the valve forming portion 23 lifts from the valve seat 10, so that the pressure receiving diameter φB is maintained. That is, when the valve forming portion 23 and the valve seat 10 are simply in contact with each other when the valve is closed as in the first embodiment, the valve forming portion 23 is lifted from the valve seat 10 when the valve is opened. The pressure receiving diameter tends to be small. However, the pressure can be held by providing the pressure receiving holding portion 310 around the valve portion as in this embodiment, and the change in the pressure receiving diameter can be reduced. That is, a large load in the valve opening direction received by the plug 303 can be maintained regardless of the stroke of the valve portion, and the valve portion can be quickly opened.

In the present embodiment, the shape of the cutout portion 311 is set so that the throttle channel has a trapezoidal shape, but it may be set to have a triangular shape or other shapes.
[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described. The differential pressure valve according to the present embodiment is substantially the same as the configuration of the differential pressure valve of the third embodiment except that the structure of the plug is different. Therefore, the same reference numerals are assigned to substantially the same components. Therefore, the description is omitted. FIG. 14 is a front view illustrating the configuration of the differential pressure valve according to the fourth embodiment. FIG. 15 is a cross-sectional view taken along the line E-E in FIG. 14 and shows a closed state of the differential pressure valve. Further, FIG. 16 is a cross-sectional view showing the configuration of the differential pressure valve in the open state, and corresponds to FIG.

  As shown in FIG. 14, the differential pressure valve 401 is constructed by coaxially assembling a stepped cylindrical housing 302 made of brass and a bottomed cylindrical plug 403 made of a resin material.

  As shown in FIGS. 15 and 16, the plug 403 is provided with six openings 425 at equal intervals in the circumferential direction in the vicinity of the periphery of the bottom of the valve body forming portion 421. The opening 425 does not open in the side portion of the valve body forming portion 421 and is formed so as to penetrate the bottom portion in the axial direction (that is, the opening / closing direction of the valve portion). For this reason, when the valve is opened, the refrigerant introduced from the inlet 4 is led to the downstream side in the axial direction through the opening 425.

  In each of the above embodiments, an example in which a conical coil spring is provided as an urging means for pulling the plug into the housing side has been described. However, a coil spring having a shape other than a conical shape may be used. Other urging means may be used as long as it can be urged.

  Moreover, although the example which applied this invention to the differential pressure | voltage valve installed in the variable capacity compressor of the clutchless system of an automotive air conditioner was shown, the use is not restricted to this, The fluid which regulates the flow of fluid to one direction Any differential pressure valve arranged in the passage is applicable.

It is a front view showing the structure of the differential pressure valve which concerns on 1st Embodiment. It is AA arrow sectional drawing of FIG. It is BB arrow sectional drawing of FIG. It is sectional drawing showing the structure of the differential pressure | voltage valve in the valve opening state. It is a front view showing the structure of the differential pressure valve which concerns on 2nd Embodiment. It is CC sectional view taken on the line of FIG. It is sectional drawing showing the structure of the differential pressure | voltage valve in the valve opening state. It is a front view showing the structure of the differential pressure valve which concerns on 3rd Embodiment. It is DD sectional view taken on the line of FIG. It is sectional drawing showing the structure of the differential pressure | voltage valve in the valve opening state. It is sectional drawing showing the structure of a plug. It is an E direction arrow directional view of FIG. It is a F direction arrow line view of FIG. It is a front view showing the structure of the differential pressure | voltage valve which concerns on 4th Embodiment. It is EE arrow sectional drawing of FIG. It is sectional drawing showing the structure of the differential pressure | voltage valve in the valve opening state.

Explanation of symbols

1,201,301,401 Differential pressure valve 2,302 Housing 3,203,303,403 Plug 4 Inlet 5 Outlet 10 Valve seat 21,221, 321,421 Valve body forming part 22 Casing part 23 Valve forming part 24 Guide Part 25,225,325,425 opening part 26 extension part 29 base part 30 regulation part 31 damper chamber 310 pressure receiving holding part

Claims (14)

In the differential pressure valve that opens and closes based on the differential pressure across the valve,
A housing having a fluid inlet on one end and a valve seat formed near the outlet on the other end;
A valve forming portion that is attached to the housing so as to cover the other end, opens and closes the valve portion by being attached to the valve seat, and slides in an opening / closing direction of the valve portion along the outer peripheral surface of the housing A plug having a guide part, an opening formed between the valve forming part and the guide part for leading the fluid that has passed through the valve part, and an extension part extending into the housing;
A biasing means disposed in the housing and biasing the plug in the valve closing direction via the extension;
A differential pressure valve characterized by comprising: The valve seat is configured from a tip surface on the other end side of the housing,
The valve forming portion is configured from a portion of the plug facing the valve seat;
The differential pressure valve according to claim 1.   The said opening part is provided in the outer position of the said valve part in the said plug, and consists of a 1 or several hole part which penetrates the said plug in the opening-and-closing direction of the said valve part. Differential pressure valve. The housing has a stepped cylindrical shape whose outer diameter decreases toward the other end side, while the plug has a stepped cylindrical shape whose inner diameter increases toward the opening end thereof,
A restriction between the outer peripheral surface of the housing and the inner peripheral surface of the plug to restrict the lift amount of the valve forming portion from the valve seat by locking the sliding of the plug when the valve portion is fully opened. That the structure was provided,
The differential pressure valve according to claim 1.   The plug is configured such that a portion excluding the extension portion is substantially complementary to the outer peripheral surface on the other end side of the housing, and is substantially fitted with the housing when the valve is closed. The differential pressure valve according to claim 1.   The differential pressure valve according to claim 1, wherein the extension portion is configured to have a length that does not protrude outside the housing even when the valve is closed.   The differential pressure valve according to claim 5, wherein a damper chamber is configured by a space portion formed between an outer peripheral surface of the housing and an inner peripheral surface of the plug.   The differential pressure valve according to claim 1, wherein the valve forming portion, the guide portion, the opening portion, and the extending portion of the plug are integrally formed of a resin material.   2. The urging means comprises a coil spring interposed between a spring seat formed on an inner wall of the housing and a spring receiver provided at a distal end portion of the extension portion. Differential pressure valve.   2. The differential pressure valve according to claim 1, wherein the differential pressure valve is arranged in a refrigerant passage connected to a discharge chamber of a variable capacity compressor of an air conditioner for an automobile and controls a flow of the refrigerant as the fluid.   The pressure receiving holding part which suppresses the reduction | decrease of the pressure receiving diameter of the part which receives the load of a valve opening direction in the said plug when the said valve formation part lifts from the said valve seat is provided. Differential pressure valve.   The differential pressure valve according to claim 11, wherein the pressure receiving holding portion is configured such that the pressure receiving diameter is larger when the valve is opened than when the valve is closed.   The differential pressure valve according to claim 12, wherein the pressure receiving holding portion is configured by a wall portion extending from the valve forming portion of the plug and surrounding the other end portion of the housing including the valve seat. The differential pressure valve according to claim 13, wherein the wall portion is formed with a notch that forms a throttle flow path for the fluid with the other end of the housing when the valve is opened.

Images