WO2019090461A1

WO2019090461A1 - Improved diaphragm valve

Info

Publication number: WO2019090461A1
Application number: PCT/CN2017/109667
Authority: WO
Inventors: Yi Liu; Jing Cheng; Qiang Wang
Original assignee: Norgren Manufacturing Co., Ltd.
Priority date: 2017-11-07
Filing date: 2017-11-07
Publication date: 2019-05-16
Also published as: CN111556941A

Abstract

A pilot actuated diaphragm valve (10). The valve (10) has an inlet (34), an outlet (36), a diaphragm (40), a bleed channel (26), and an annular filter (100). The bleed channel (26) has a bleed channel axis X. The annular filter (100) is arranged upstream of the diaphragm (40). The bleed channel (26) is arranged upstream of the diaphragm (40). The annular filter (100) is axially aligned with the inlet (34). The annular filter (100) is orthogonally aligned with the bleed channel axis X, arranged to prevent contaminants entering the bleed channel (26). A coolant control system for a vehicle, the coolant control system comprising a pilot actuated diaphragm valve (10).

Description

Improved Diaphragm Valve

TECHNICAL FIELD

The present disclosure relates to an improved diaphragm valve. Particularly, but not exclusively, the disclosure relates to a pilot actuated diaphragm valve. Aspects of the invention relate to a pilot actuated diaphragm valve and to a coolant control system for a vehicle.

BACKGROUND

Diaphragm valves are known. Typically, the bleed channel is provided on the diaphragm. However, this may lead to blockages due to contaminants or debris carried by the fluid flowing through the diaphragm valve. To prevent such contaminant or debris blocking the bleed channel and impairing the function of the diaphragm valve, a filter may be used. However, the use of a filter restricts the fluid flow through the valve.

The present invention aims to solve one or more of the above problems.

SUMMARY OF THE INVENTION

Aspects and embodiments of the invention provide a pilot actuated diaphragm valve and a coolant control system for a vehicle as claimed in the appended claims.

According to an aspect of the invention, there is provided a pilot actuated diaphragm valve having: an inlet, an outlet, a diaphragm, a bleed channel having a bleed channel axis X, and an annular filter, wherein: the annular filter is arranged upstream of the diaphragm, the bleed channel is arranged upstream of the diaphragm, the annular filter is axially aligned with the inlet, the annular filter is orthogonally aligned with the bleed channel axis X, arranged to prevent contaminants entering the bleed channel.

The present invention moves the bleed channel away from the diaphragm, and uses an annular filter to prevent debris in the fluid from blocking the bleed channel. Furthermore, the annular shape of the filter minimizes flow disruption, even when contaminants or debris begin to collect temporarily on the filter surface.

The bleed channel may be provided in the valve body.

The annular filter may be located within an annular recess defined at least in part by the valve body. This arrangement means that the filter provides minimal disruption to the primary flow of fluid through the valve, from the inlet to the outlet. Primary fluid flow through the valve is unrestricted by the presence of the annular filter.

The annular recess may be defined between the valve body and an inlet fitting assembly such that an inner surface of the annular filter remains flush with the respective inner surfaces of the inlet fitting assembly and the valve body. This arrangement provides a self-cleaning function, such that the primary flow of fluid through the valve, from the inlet to the outlet, washes across the surface of the annular filter to remove any contaminants or debris that may begin to collect there. The self-cleaning function means that it is not necessary to service the diaphragm valve during the lifetime of the diaphragm valve.

The annular recess may define a circumferentially extending channel between the annular filter and the bleed channel. This arrangement ensures that fluid flow to the bleed channel is available via the filter even if a portion of the filter is temporarily blocked, for example by any contaminants or debris that may have begun to collect on a portion of the filter.

The annular filter may comprise at least one mesh portion.

The at least one mesh portion may have a mesh pore size that is smaller than a diameter D of the bleed channel. This ensures that the bleed channel is not blocked by contaminants or debris carried by the fluid flowing through the diaphragm valve. Such contaminants or debris may otherwise cause the diaphragm to malfunction.

The at least one mesh portion may have a mesh pore size that is smaller than a distance d of a slipping gap between an armature assembly and an inner surface of an armature bore. This ensures that the slipping gap of armature assembly is not blocked by contaminants or debris carried by the fluid flowing through the diaphragm valve. Such contaminants or debris may otherwise cause the diaphragm to malfunction. For example, in diaphragm valve, the armature assembly of pilot valve must be able to lift up and fall down smoothly, otherwise, the diaphragm valve can’t work normally.

The diaphragm may include a bleed channel aperture provided on a first tab.

According to another aspect of the invention, there is provided a coolant control system for a vehicle, the coolant control system comprising a pilot actuated diaphragm valve as hereinbefore described.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of the diaphragm valve of the present invention;

Figure 2 is an exploded view of the diaphragm valve of Figure 1;

Figure 3 is a cross-sectional view of the diaphragm valve of Figure 1 in a closed condition;

Figure 4 is a perspective view of the annular filter of the present invention; and

Figure 5 is a cross-sectional view of the diaphragm valve of Figure 1 in an open condition;

Figure 6 is a schematic vehicle coolant system diagram;

DETAILED DESCRIPTION

Referring to Figures 1 and 2, a diaphragm valve 10 is shown. The diaphragm valve 10 is a 2/2 way valve, having two ports and two valve conditions -open and closed. The diaphragm valve 10 is indirectly actuated and is normally closed (open when energised) .

The diaphragm valve 10 has a valve body 20, an inlet fitting assembly 30, an outlet fitting assembly 32, a diaphragm 40, a guiding piece 50, a cover assembly 60, a pilot valve assembly 70 and annular filter 100.

The valve body 20 has an inlet channel 22 and an outlet channel 24, both defined by a valve body wall. The inlet channel 22 and the outlet channel 24 meet in a region having an upstanding wall, defining an inner orifice 25 and an outer orifice 23. The upstanding wall terminates in an annular main valve seat 38. The main valve seat 38 separates the inner orifice 25 and the outer orifice 23.

The inlet channel 22 further defines an annular shoulder 16. Upstream of the annular shoulder 16, the valve body wall has a bleed orifice having a diameter D. the bleed orifice extends as a bleed channel 26 through the valve body wall. The bleed channel 26 has an axis X.

The outlet channel 24 has a pilot orifice, which extends as a pilot channel 28 through the valve body wall.

The inlet fitting assembly 30 is a pipe having a flanged attachment region 31. The inlet fitting assembly 30 defines the diaphragm valve inlet 34. Similarly, the outlet fitting assembly 32 is a pipe having a flanged attachment region 33. The outlet fitting assembly 32 defines the diaphragm valve outlet 36.

The cover assembly 60 defines chamber 62. Chamber 62 is fluidly connected to the bleed bore of the valve body 20. Chamber 62 is also fluidly connected to the pilot bore, as will be described in more detail below. The cover assembly includes a flanged attachment region 64 for attachment to the valve body 20. The cover assembly 60 also includes a pilot valve assembly receiving region 66, for receiving the pilot valve assembly 70. In the assembly receiving region 66, a pilot valve seat 80 is provided at an upper end of a pilot channel.

The diaphragm 40 is a flexible disc having a centrally aligned main aperture 42 for fixing about the guiding piece 50. The diaphragm further includes a bleed channel aperture 44 provided on a first tab 45 and a pilot channel aperture 46 provided on a second tab 47.

The guiding piece 50 has four downwardly depending prongs 52, an annular recess 54 for receiving the diaphragm 40 and a circular retaining flange 56.

The pilot valve assembly 70 includes a coil assembly 72, an armature assembly 74, a return spring 76, a pilot valve member 78 and a pilot valve seat 80. The armature assembly 74 moves within an armature bore 84. The slipping gap 82, that is, the gap between the armature assembly 74 and an inner surface of the armature bore 84 is a distance d.

The annular filter 100 (see Figure 4) has two annular flanges -an upstream annular flange 102 and a downstream annular flange 104. The two annular flanges are joined by four webs 106. The

annular flanges

102, 104 and four webs 106 define, between them, four pockets 108 which are covered in a mesh 110. The mesh 110 provides a substantially flush inner surface, together with the two

annular flanges

102, 104 joined by four webs 106. On an outer surface of the annular filter 100, the

annular flanges

102, 104 extend radially further than the four webs 106, such that a circumferentially extending channel 112 is defined.

Assembly of the diaphragm valve 10

The annular filter 100 is inserted into the inlet channel 22 of the valve body 20, such that the downstream annular flange 104 abuts the annular shoulder 16. In this position, the mesh 110 of the annular filter 100 is orthogonally aligned with the axis X of the bleed channel 26. The annular filter 100 is orthogonally aligned with the bleed channel axis X, arranged to prevent contaminants entering the bleed channel 26.

The inlet fitting assembly 30 is joined to the valve body 20 via the flanged attachment region 31 such the end of the inlet fitting assembly 30 abuts the upstream annular flange 102 of the annular filter 100. Thus the annular filter 100 is secured in an annular recess 18 between the inlet fitting assembly 30 and the valve body 20. Furthermore, the inner surface of the annular filter 100 remains flush with the respective inner surfaces of the inlet fitting assembly 30 and the valve body 100.

An O-ring seal 14 is included between the inlet fitting assembly 30 and the valve body 20 to ensure a fluid tight connection. The inlet 34 and inlet channel 22 are thus fluidly connected, and in use, coolant will predominantly flow axially through the annular filter 100. Coolant may also flow from the inlet 34 to the bleed channel, via the mesh 110. Given the radially extending

annular flanges

102, 104, the coolant may flow circumferentially, in the circumferentially extending channel 112, before entering the bleed channel.

The diaphragm 40 is joined to the guiding piece 50, with the centrally aligned main aperture 42 fixed about the annular recess 54. The guiding piece 50 is inserted into the inner orifice 25 such that the four downwardly depending prongs 52 abut the inner wall surface of the upstanding wall. The diaphragm 40 thereby seals against the main valve seat 38.

The bleed channel aperture 44 is aligned with the bleed channel and the pilot channel aperture 44 is aligned with the pilot channel. The cover assembly 60 sandwiches the periphery of the diaphragm 40, including the first and

second tabs

45, 47, against the valve body 20. The cover assembly 60 is attached to the valve body 20 at attachment region 64.

The outlet fitting assembly 32 is joined to the valve body 20 via the flanged attachment region 33. An O-ring seal 15 is included between the outlet fitting assembly 32 and the valve body 20 to ensure a fluid tight connection. The outlet channel 24 and the outlet 36 are thus fluidly connected, and in use, with the diaphragm valve 10 open, coolant will predominantly flow from chamber 62 to the outlet 36, via the outlet channel 24. Coolant may also flow from the chamber 62 to the outlet 36, via the bleed pilot channel.

Function of the diaphragm valve 10

Referring to Figure 3, when the coil assembly 72 of pilot valve assembly 70 is de-energized, the armature assembly 74 closes the pilot valve by the pilot valve member 78 being urged against the pilot valve seat 80 by return spring 76.

The inlet pressure passes through the bleed channel 26, this pressure multiplied by the surface area of the upper side of the diaphragm 40, produces a force which is larger than the force on the underside of the diaphragm 40. So, the diaphragm 40 is pressed onto the main valve seat 38 and the diaphragm valve 10 is closed. Thus the diaphragm valve 10 operates in a normally closed condition.

Referring to Figure 5, when the coil assembly 72 of pilot valve assembly 70 is energized, the armature assembly 74 is lifted up from pilot valve seat 80.

The pressure over the diaphragm 40 is vented through the open pilot valve seat 80. More fluid flows out of the pilot valve than passes through the bleed channel 26, because the pilot valve seat 80 area is larger than the bleed channel 26 area, which causes a pressure difference. The increasing force on the underside of the diaphragm 40 lifts the diaphragm 40 from the main valve seat 38 and opens the diaphragm valve 10.

To ensure proper functioning of the diaphragm valve 10, the bleed channel 26 must not be blocked, and equally, the armature assembly 74 of pilot valve assembly 70 must be free to move within the bore 84.

The filter mesh 110 is selected so that the maximum dimension of the pores within the mesh (mesh size) is smaller than both the slipping gap 82 distance d and the bleed channel 26 diameter D. Therefore the filter mesh 100 prevents any contaminants within the coolant from entering and potentially blocking the bleed channel 26 and/or smooth operation of the armature assembly 74.

In normal operation of the diaphragm valve, it is possible that some debris may block a portion of the mesh 110 of annular filter 100 for a short period of time. However, due to the provision of the circumferentially extending channel 112 in the annular filter 100, the coolant may still pass through the annular filter 100 and bleed channel via another portion of the mesh 110. Therefore the function of diaphragm valve is not adversely affected.

Furthermore, since the annular filter is axially aligned with the predominant flow direction of coolant entering the diaphragm valve 10, any debris that begins to collect on the mesh 110 will be flushed away by the coolant fluid inertia. This means it is not necessary to take the annular filter 100 out and clean it manually.

Yet furthermore, given the flush arrangement of the annular filter 100 within the annular recess 18, the flow rate of diaphragm valve 10 is not restricted.

When returning the diaphragm valve to the closed condition, as shown in Figure 3, the guiding piece 50, and specifically the four downwardly depending prongs 52 ensure that the diaphragm 40 is centrally aligned in the inner orifice 25, such that a good seal is formed between the diaphragm 40 and the annular main valve seat 38. The guiding piece 50 furthermore provides an attenuated closing operation even in the case of a high flow rate through the diaphragm valve 10. This prevents a so-called water hammer effect.

Figure 6 shows a coolant control system for a vehicle 210. The coolant control system comprising four diaphragm valves 10, which are used to control the flow of coolant from the an engine heat exchanger through a pressure reduction valve and a filter 220 to heat exchangers 230 distributed throughout the passenger cabin. The vehicle is a passenger bus, commonly used for inter-and intra-city travel. The diaphragm valve 10 is controlled by using an electrical current signal to control the opening and closing of the coolant liquid flow paths.

The function is covered by a 2/2 way indirect acting valve normally closed, open when energized. This arrangement provides an open loop control strategy. This arrangement provides a more economical solution as compared to individual motorized valves.

The skilled person will appreciate that an alternate coolant control system may employ an alternate number of diaphragm valves. Furthermore, the skilled person will appreciate that the diaphragm valve of the present invention is not restricted to being used with a coolant control system, but may be employed in other systems. The media is not restricted to coolant, and may be any fluid such as air, water etc.

Claims

A pilot actuated diaphragm valve having:

an inlet, an outlet, a diaphragm, a bleed channel having a bleed channel axis X, and an annular filter, wherein:

the annular filter is arranged upstream of the diaphragm,

the bleed channel is arranged upstream of the diaphragm,

the annular filter is axially aligned with the inlet,

the annular filter is orthogonally aligned with the bleed channel axis X, arranged to prevent contaminants entering the bleed channel.
A pilot actuated diaphragm valve according to claim 1 having a valve body, wherein the bleed channel is provided in the valve body.
A pilot actuated diaphragm valve according to claim 2, wherein the annular filter is located within an annular recess defined at least in part by the valve body.
A pilot actuated diaphragm valve according to claim 3, wherein the annular recess is defined between the valve body and an inlet fitting assembly such that an inner surface of the annular filter remains flush with the respective inner surfaces of the inlet fitting assembly and the valve body.
A pilot actuated diaphragm valve according to claim 3, wherein the annular recess defines a circumferentially extending channel between the annular filter and the bleed channel.
A pilot actuated diaphragm valve according to any of claims 1 to 5, wherein the annular filter comprises at least one mesh portion.
A pilot actuated diaphragm valve according to claim 6, wherein the at least one mesh portion has a mesh pore size that is smaller than a diameter D of the bleed channel.
A pilot actuated diaphragm valve according to claim 6, wherein the at least one mesh portion has a mesh pore size that is smaller than a distance d of a slipping gap between an armature assembly and an inner surface of an armature bore.
A pilot actuated diaphragm valve according to any preceding claim, wherein the diaphragm includes a bleed channel aperture provided on a first tab.
A coolant control system for a vehicle, the coolant control system comprising a pilot actuated diaphragm valve according to any of claims 1 to 9.