WO2006078607A1

WO2006078607A1 - Butterfly valve seal and bypass shutoff

Info

Publication number: WO2006078607A1
Application number: PCT/US2006/001509
Authority: WO
Inventors: Richard Stonely
Original assignee: Cooper Standard Automotive Inc
Current assignee: Cooper Standard Automotive Inc
Priority date: 2005-01-18
Filing date: 2006-01-18
Publication date: 2006-07-27
Anticipated expiration: 2007-07-18
Also published as: CA2593210A1; GB2435588A; WO2006078607B1; DE112006000232T5; MX2007008682A; GB0711466D0

Abstract

A valve system (18) includes an actuator (38) that selectively drives a valve member (42) between a first position and a second position to control fluid flow to an outlet port (34) and a bypass port (36). A temperature sensor (19) indicates a fluid temperature to a controller (21), which controls the actuator (38) to control the position of the valve member (42) based upon the fluid temperature. A bias feature (41a, 41b) biases the valve member (42) toward one of the first position or the second position in response to an inoperable state of the actuator (38).

Description

BUTTERFLY VALVE SEAL AND BYPASS SHUTOFF

Field of the Invention

This invention relates to a flow control valve and, more particularly, to a butterfly valve in a vehicle coolant system that controls coolant flow into a heat exchanger and bypasses coolant flow into an engine. Description of the Related Art

Vehicle combustion engines generate heat from the combustion of fuel and the friction between moving parts within the engine. An engine coolant system circulates a coolant through flow passages between the engine and a heat exchanger, such as a radiator. The coolant carries the heat from the engine to the radiator, which is exposed to ambient airflow passing over the surface of the radiator to transfer the heat from the coolant to the airflow. The coolant then circulates back to the engine, and the engine cooling cycle repeats. Coolant hoses or tubes typically carry the coolant between the engine and the radiator.

Typically, the radiator system includes a bypass conduit located upstream from the radiator. When the coolant temperature is within a selected "cold" temperature range, such as when the vehicle is initially started, the coolant does not require cooling in the radiator. In response, a valve system closes a first valve to prevent coolant flow to the radiator and opens a second valve to allow coolant flow to the bypass conduit. The bypass conduit circulates the coolant into the engine, thereby circumventing coolant flow through the radiator. At a later time, when the coolant temperature increases, the valve system opens the first valve to allow coolant flow to the radiator and closes the second valve to prevent flow to the bypass conduit.

Typical valve systems include multiple valves and actuators to respectively open and close the various flow paths. Disadvantageously, these systems may be bulky, expensive, prone to sticking in an open or a closed position, and may provide poor sealing. Accordingly, a more compact, economic, and reliable valve system is needed. This invention addresses those needs and provides enhanced capabilities while avoiding the shortcomings and drawbacks of the prior art. SUMMARY OF THE INVENTION

One example valve system according to the present invention includes an actuator that selectively drives a valve member between a first position and a second position to control fluid flow through a plurality of passages. The fluid is received through an inlet port and flows through one or more of the plurality of passages. A temperature sensor indicates a fluid temperature to a controller, which controls the actuator to control the position of the valve member based upon the fluid temperature.

In one example, heated fluid from an engine flows into the valve system. When the temperature sensor detects a temperature above a threshold, the controller activates the actuator to move the valve member to the second position to allow fluid flow through an outlet port to a heat exchanger. When in the second position, the fluid is prevented from flowing through a bypass port. When the temperature sensor detects a fluid temperature below the threshold, the controller activates the actuator to move the valve member to the first position to allow fluid flow through the bypass port to bypass flow to the heat exchanger. In one example, a bias feature biases the valve member toward the first position such that the fluid flows to the heat exchanger if the actuator becomes inoperable.

The above examples are not intended to be limiting. Additional examples are described below. The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows. Figure 1 is a schematic view of the example engine coolant system;

Figure 2 is a perspective cutaway view of an example valve system in an open position; Figure 3 is an end view of the example valve system shown in Figure 2;

Figure 4 is a cross-sectional view of the example valve system shown in Figure 2;

Figure 5 is a perspective cutaway view of the example valve system in a closed position;

Figure 6 is a cross-sectional view of the valve system shown in Figure 5;

Figure 7 is an isolated view of the butterfly valve of the valve system shown in Figure 5;

Figure 8 is a perspective cutaway view of the example valve system in an intermediate position;

Figure 9 is a cross-sectional view of the valve system shown in Figure 8; and

Figure 10 is an end view of the valve system shown in Figure 8.

DETAILED DESCRIPTION Figure 1 is a schematic view of an example engine coolant system 10. The engine coolant system 10 includes a combustion engine 12 that, for example, burns fuel for the purpose of moving a vehicle. Conduits 14 circulate a coolant between the combustion engine 12 and a heat exchanger 16, such as a radiator. The coolant absorbs heat from the combustion engine 12 and transfers the heat to the heat exchanger 16. The heat exchanger 16 rejects the heat in the coolant to an airflow passing over the surface of the heat exchanger 16, heating the airflow. The coolant then returns to the combustion engine 12, completing the cycle.

The engine coolant system 10 includes a valve system 18 that controls coolant flow to the heat exchanger 16 and to a bypass conduit 20 based upon a coolant temperature. In the illustrated example, a temperature sensor 19 is located upstream from the valve system 18 to measure the coolant temperature. The temperature sensor communicates a signal indicative of the coolant temperature to a controller 21, which is in communication with the valve system 18.

When the coolant temperature is "cold" or below a threshold temperature, the controller 21 commands the valve system 18 to direct the coolant into the bypass conduit 20 rather than to the heat exchanger 16. When the coolant temperature is "hot" or above the threshold temperature, the controller 21 commands the valve system 18 to direct the coolant to the heat exchanger 16. This provides the benefit of increased efficiency in the engine coolant system 10. It is to be understood that in this example, terms such as "cold" and "hot" are relative to the operating conditions of the particular system in which the valve system 19 operates. Figure 2 is a perspective cutaway view of the example valve system 18 shown in Figure 1. The valve system 18 includes a valve housing 30, which is made from a metal or is molded from a plastic material. The valve housing 30 includes an inlet port 32 and an outlet port 34. The inlet port 32 connects to the conduit 14 and receives coolant from the combustion engine 12. The outlet port 34 provides a coolant egress from the valve housing 30, through the conduit 14, and to the heat exchanger 16. In the illustrated example, a bypass port 36 extends substantially perpendicular to the flow path through the valve housing 30.

In this example, an actuator 38 is mounted on a periphery of the valve housing 30. The actuator 38 engages an axle 40 and rotates the axle 40 to position a butterfly valve 42 between open, closed, or intermediate positions. The butterfly valve 42, partially cutaway in the illustrated example, rotates within the valve housing 30 between various functional positions.

Figures 2-4 show the butterfly valve 42 in a second position, wherein coolant entering the inlet port 32 flows through the valve housing 30 and exits the outlet port 34 to flow to the heat exchanger 16. When the temperature sensor 19 detects that the coolant is above a threshold temperature, the controller 21 signals the actuator to rotate the axle 40 to move the butterfly valve 42 to the second position. Given this description, one of ordinary skill in the art will recognize suitable threshold temperatures to meet the particular needs of their system. While in the second position, the butterfly valve 42 seals against an end 44 of the bypass port 36, which extends through the valve housing 30 into the inlet port 32. The seal prevents coolant from entering the bypass port 36 and flowing through the bypass conduit 20 to the engine 12. This example arrangement is compact and eliminates the use of several different valves to control flow between the heat exchanger 16 and the bypass conduit 20.

Figures 5 and 6 show, respectively, a perspective cutaway view and a cross- sectional view of the valve system 18 when the butterfly valve 42 is in a first position. When the temperature sensor 19 detects that the coolant is below the threshold temperature, the controller 21 signals the actuator to rotate the axle 40 to move the butterfly valve 42 to the first position.

While in the first position, the butterfly valve 42 seals against opposing portions 41a and 41b of the butterfly valve 42 against corresponding opposing valve seats 46a and 46b that extend from the valve housing 30.

The valve seats 46a and 46b in this example are protrusions that extend partially around an inner circumference of valve housing walls 50 of the valve housing 30 to define respective planes. The planes formed by the protrusions are offset a distance D from a plane formed by the butterfly valve 42 such that one of the protrusions seals against one side of the butterfly valve 42 and the other protrusion seals against the other side of the butterfly valve 32 when the butterfly valve 32 is rotated to the closed position. The protrusions include a flat mating surface 52 that seals against a flat mating surface 54 on the butterfly valve 42. The protrusions also seal against the axle 40, for added protection from leaking across the butterfly valve 42. These features provide the benefit of a low-leak and reliable valving system.

Referring to Figure 7, the opposing portions 41a and 41b of the butterfly valve 42 have different areas, A₁ and A₂ respectively, from each other and function as a biasing feature. In the example shown, the area A₂ of the portion 41b is relatively larger than the area A₁ of the other portion 41a. In the first position, coolant that presses against the butterfly valve 42 produces a pressure difference between the differing areas A₁ and A₂ of the opposing portions 41a and 41b. The pressure difference biases the butterfly valve 42 toward the second position. In other words, in the event that the actuator 38 loses power or otherwise becomes inoperable, the pressure difference creates a torque on the axle 40 such that the butterfly valve 42 moves from the first position toward the second position. This provides the advantage of allowing the coolant to circulate through the engine coolant system 10 and to be cooled by the heat exchanger 16, thereby protecting the engine from over-heating when the actuator 38 is inoperable.

Figures 8-10 show the butterfly valve 42 in an intermediate position between the second position and the first position. When the temperature sensor 19 detects that the coolant is below a first threshold temperature and above a second threshold temperature, the controller 21 signals the actuator to rotate the axle 40 to move the butterfly valve 42 from either the second position or the first position to the intermediate position. As can be appreciated, the intermediate position can be any position between the second position and the first position.

In the intermediate position, the coolant is permitted to simultaneously flow through the bypass port 36 and out of the outlet port 34 to the heat exchanger 16. This provides the benefit of increasing the efficiency of the engine coolant system 10 when the temperature sensor 21 indicates that the coolant temperature is slightly above a predetermined "cold" temperature, for example.

The disclosed examples also provide a pressure-balanced design wherein the coolant pressure at the inlet port 32 is essentially equal to the coolant pressure at the outlet port 34. This is due to the essentially linear flow path through the valve housing 30 from the inlet port 32 to the outlet port 34. Previously known designs may include geometries that create a circuitous flow path through a valve housing, which may cause an undesirable pressure differential between the inlet port and the outlet port.

Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.

Claims

1. A valve system comprising: an actuator; a valve member driven by the actuator and selectively moveable between a first position and a second position to control flow through a plurality of passages; and a bias feature that biases the valve member toward one of the first position or the second position in response to an inoperable state of the actuator.

2. The valve system as recited in Claim 1, wherein the bias feature comprises the valve member having oppositely located surfaces of unequal area.

3. The valve system as recited in Claim 2, wherein the oppositely located surfaces are substantially semi-circular.

4. The valve system as recited in Claim 3, wherein the valve member comprises a disk.

5. The valve system as recited in claim 2, wherein the oppositely located surfaces induce a pressure differential on the valve member in response to coolant flow against the valve member that biases the valve member toward the one of the first position or the second position.

6. The valve system as recited in Claim 1, wherein the valve member includes an inlet port, and at least one of the plurality of passages comprises a bypass port having an end portion that extends at least partially into the inlet port.

7. The valve system as recited in Claim 6, wherein the valve member seals against the end portion of the bypass port in one of the first position or the second position to prevent flow into the bypass port.

8. The valve system as recited in Claim 6, wherein the bypass port is substantially perpendicular to the inlet port.

9. The valve system as recited in Claim 1, wherein the valve member includes a first surface that generally faces in a flow-receiving direction and a second surface that faces in an opposite direction.

10. The valve system as recited in Claim 9, wherein the first surface seals against a first valve seat within one of the plurality of passages and the second surface seals against a second valve seat within the one of the plurality of passages when in the first position.

11. The valve system as recited in Claim 10, wherein the first valve seat includes a first seal surface that faces in a first direction and the second valve seat includes a second seal surface that faces in a second direction that is opposite of the first direction.

12. The valve system as recited in Claim 10, wherein the valve member comprises an axle in driving communication with the actuator, and each of the first valve seat and the second valve seat seal against the axle.

13. The valve system as recited in Claim 10, wherein the first valve seat defines a first plane and the second valve seat defines a second plane that is non-planar with the first plane.

14. The valve system as recited in Claim 13, wherein the valve member defines a valve member plane that is non-planar with each of the first plane and the second plane.

15. The valve system as recited in Claim 10, wherein the first surface seals against an end portion of another of the plurality of passages when in the second position.

16. A method of controlling a valve member that is driven by an actuator between a first position and a second position to control flow through a plurality of passages, comprising the steps of: biasing the valve member toward one of the first position or the second position in response to an inoperable state of an actuator that moves the valve member.

17. The method as recited in Claim 16, including the step of generating a pressure differential on the valve member in response to coolant flow against the valve member to bias the valve member toward the one of the first position or the second position.

18. The method as recited in Claim 17, including the step of pivoting the valve member about an axis that extends through the valve member in response to the pressure differential.

19. The method as recited in Claim 17, wherein the first position allows coolant to flow to a heat exchanger and the second position allows coolant to bypass the heat exchanger, and the method includes the step of biasing the valve member to the first position.

20. The method as recited in Claim 19, including the step of sealing the valve member against a first seal surface in the first position and against a pair of oppositely-facing seal surfaces in the second position.

21. A coolant system comprising: a heat exchanger; a combustion engine; a coolant loop that fluidly connects the heat exchanger and the combustion engine; and a bypass valve within the coolant loop, the bypass valve comprising: an actuator; a valve member driven by the actuator and selectively moveable between a first position that allows fluid flow to bypass the heat exchanger and a second position that allows fluid flow to the heat exchanger; and a bias feature that biases the valve member toward the second position in response to an inoperable state of the actuator.