MOTOR THERMOSTAT HAVING A PRESSURE DAMPING FLUID DERIVATION PASSAGE Field of the Invention This invention relates to internal combustion engines, including, but not limited to, controlling a flow of the engine cooling system with a thermostat device. . BACKGROUND OF THE INVENTION Internal combustion engines have cooling systems associated with them, which transfer heat away from the motor structure. These cooling systems typically include thermally operated devices, which can channel a flow of cooling fluid either into the interior of the engine or into a radiator, depending on the temperature of the cooling flow. Typical motor thermostats are 3-way valves that have one intake and three discharges. A first hole thereof acts as an admission for the flow of control fluid. A second orifice thereof which acts as a first discharge, when opened, directs the flow of cooling fluid directly into the engine when the cooling flow is at a low temperature. A third hole of them that acts as a
The second discharge, when opened, allows the flow of cooling fluid to be diverted from the engine and pass through a radiator. Where it gets cold, before returning to the engine. An activator controls the opening of the valves that control the flow of the cooling fluid to the first and / or the second discharge. The thermal actuator, typically a material that pushes a rod when it is heated and expanded, is immersed in the flow of cooling fluid entering the thermostat inlet. When an engine operates at high engine speed conditions, the flow of cooling fluid increases. This increased flow rate often causes instabilities during the transition periods at a position of the thermostat. These instabilities are often the result of the effects of hovercraft on the thermostat plates that are used to fluidly block the second and third holes. These instabilities often cause the plates to vibrate or knock loudly against their valve seats, thus causing damage to them. Brief Description of the Invention A thermostat assembly includes a portion of the actuator that has a sealed container with an arm protruding therefrom. A retainer plate connects the assembly
from thermostat to a motor component. A bypass valve plate is arranged to sealingly engage a bypass valve seat that is formed in the first motor component. The bypass valve plate includes a body portion, a central opening and an outer periphery, an inner ring surrounding the central opening, an outer ring surrounding the outer periphery, a plurality of openings formed in the body portion. The openings are disposed adjacent an interface between the body portion and the outer ring, such that a bypass passage of the pressure damping fluid is defined through the plurality of openings in the bypass valve plate. Brief Description of the Drawings FIG. 1 is a cross section of a thermostat assembly installed between a first and a second motor component. FIG. 2 and FIG. 3 are cross-sectional views of one embodiment of a thermostat assembly having an improved bypass valve plate. FIG. 4 and FIG. 5 are sketch views of the different perspectives of the improved bypass valve plate of the thermostat assembly shown in FIG. 2. FIG. 6 and FIG. 7 are cross views of another
mode for a thermostat assembly having a bypass valve plate and a bypass valve seat configuration, improved. FIG. 8 and FIG. 9 are cross-sectional views of another embodiment for a thermostat assembly having a bypass valve plate and improved bypass valve seat configuration. Description of a Preferred Modality The following describes an apparatus for a method for reducing the effect of instabilities in the flow of the cooling fluid through a thermostat, especially during a transition phase of the operation, by providing a passage of Improved bypass of fluid flow, which has pressure damping characteristics. In FIG. 1 is a sectional view of a known thermostat 100 when installed in an internal combustion engine between a first component 102 and a second component 104 thereof. The thermostat 100 includes a thermal actuator assembly 106. The thermal actuator assembly 106 includes an arm 108 that can be extended when heated. The arm 108 passes through a cover 110 which is sealingly and permanently attached to a container 112. The container 112 contains a "tablet
wax "114 which melts and expands under high temperature conditions A plate 115 of the thermostat non-sliply engages with the actuator assembly 106 in an inner portion thereof, and has a seal 116 over molded in an outer portion A retaining plate 118 surrounds a portion of the actuator assembly 106 and is disposed in a slot 120 of the second component 104. A first spring 122 is disposed between the plate 115 of the thermostat and the retainer plate 118. The first spring 122 pushes the plate 144 of the thermostat in the opposite direction from the holding plate 118. In a cold condition, the force of the first spring 122 acts to maintain a seated position of the holding plate 118 in the slot 120, and also to push the plate 115 of the thermostat against an external seat 124 that is formed in the second component 104. A latching device 126 is connected to the actuator assembly 106 on one side thereof which is opposite to the arm 108. The bypass valve retainer 126 has a plate 128 of the bypass valve connected to a distal end thereof. A second spring 130 is disposed between the bypass valve retainer 126 and the bypass valve plate 128, actuating to push the bypass valve plate 128 away from the actuator assembly 106. In the modality
shown, a slot 132 is formed in the first component 102 of the motor opposite to the plate 128 of the bypass valve. The slot 132 forms a seat 134 of the bypass valve which contacts the plate 128 of the bypass valve under certain conditions, usually hot conditions. During operation, a flow of refrigerant enters the thermostat 100. The flow of refrigerant, or more specifically a supply of engine coolant, enters the thermostat 100 through an intake opening 136. Sometimes when the coolant flow has a low temperature, or below 190 degrees F (88 degrees C), the wax pad 144 on the actuator assembly is mostly solid, the arm 108 rests against a support 138 which is formed in the second component 104, and the plate 128 of the bypass valve hangs away from the seat 134 of the bypass valve. Therefore, the flow of refrigerant entering through the intake opening 136, passes through the plate 128 of the bypass valve and leaves the thermostat 100 through the bypass passage, or a return passage 140 of coolant that is formed in the first component 102 and that channels the coolant flow directly back into the engine. When the flow of refrigerant entering the
Through the intake opening 136, or has a temperature above about 190 degrees F (88 degrees C), the wax tablet 114 melts and thermally expands into the container 112. Expansion of the wax tablet 114 causes that the arm 108 extends away from the container 112, pushing against the support 138. The extension of the arm 108 causes the plate 115 of the thermostat to move away from the seat 124 of the discharge, the first spring 122 is compressed, and the plate 128 of the bypass valve moves towards the seat 134 of the bypass valve. The continuous operation under hot conditions will eventually settle the plate 128 of the bypass valve on the seat 134 of the bypass valve. In this condition, the flow of refrigerant entering through the intake opening 136 will pass into a chamber 142 of the thermostat actuator 100, and will exit the thermostat through a discharge opening 144 of the radiator 144. The flow of refrigerant entering through the radiator discharge opening 144 returns to the engine after passing through a radiator (not shown). One embodiment for an improved thermostat is shown in the partial cross section of FIG. 2, and in an expanded cross-sectional view, in detail of FIG 3. The thermostat 200 has many similar features and elements with the thermostat 100, and for simplicity, the
Common elements are called using the same reference numbers. The thermostat 200 has an intake opening 136, a bypass discharge opening 140, and a radiator discharge opening 144. The thermostat 200 has an improved bypass valve plate 228. The bypass valve plate 228 is connected to the bypass valve retainer 126, and operates in substantially the same manner as the bypass valve plate 128 shown in FIG. 1, but has a plurality of openings 230 formed along the entire periphery thereof, equidistant from a central axis 232. During the operation of the thermostat 200, and especially during a transition period of heating of the cooling flow, the plate 228 of the bypass valve is pushed towards the seat 134 of the bypass valve, as described. In the thermostat 100 of FIG. 1, when the bypass valve plate 128 has been pushed into the slot 132 but is not yet seated on the seat 134 of the bypass valve, a pressure pulsation effect is created which causes a vibration in the plate 128 of the bypass valve. This vibration, over time, can lead to various types of faults in the plate 128 of the bypass valve, the detent device 126, and in general, to the functionality of the thermostat 100. This
Vibration can be advantageously avoided with the use of the plate 228 of the improved bypass valve. The openings 230 act to relieve the pressure differentials that cause the vibrations through the plate 228 of the bypass valve, and effectively eliminate the vibrations and increase the service life of the thermostat 200 in comparison with the service life of the thermostat 100. A sketch view from two different perspectives of the plate 228 of the bypass valve is shown in FIG. 3 and FIG. 4. The plate 228 of the bypass valve includes a body section 402. The body section 402 is substantially planar and has a disc shape. An outer ring 404 surrounds the body section 402 along an outer periphery thereof, and an inner ring 406 surrounds a central opening 408 of the body section 402. The outer ring 404 and the inner ring 406 advantageously provide structural rigidity to the body section 402. The plurality of openings 230 are disposed adjacent the outer periphery of the body section 402, near an interface between the body section 402 and the outer ring 404. The body section 402, the inner ring 404, the outer ring 406, the central opening 408, and the plurality 230 of openings, can advantageously be formed simultaneously in a single operation of punching and cutting a single piece of sheet
metallic During the operation of the thermostat 200, a pressure damping passage is created, between the intake opening 136, through the plurality of openings 230, through an area between the bypass valve plate 228 and the seat 134 of the bypass valve, and out of the return passage 140. The pressure damping passage is advantageously more effective for damping pressure pulsations that would otherwise cause vibrations to the bypass valve plate at the moments when the bypass valve plate 228 is transitioning to a position closed and is near and almost seated in the seat 134 of the bypass valve. In FIG. 6 and FIG. 7 is shown in a cross-sectional view, an alternative embodiment for a thermostat 600 having a passage of pressure damping fluid. The thermostat 600 has mainly similar characteristics and elements with the thermostat 100, and for simplicity, the common elements are called using the same reference numbers. The thermostat 600 has an intake opening 136, a discharge opening 140, and a radiator discharge opening 144. The thermostat 600 has a plate 628 of the improved bypass valve, and a seat 634 of the bypass valve,
improved. The plate 628 of the bypass valve is connected to the bypass valve retainer 126, and operates in a manner substantially similar to the bypass valve plate 128 shown in FIG. 1. The plate 628 of the bypass valve has an improved side surface 630. The side surface 630 has a convex conical profile for the most part, and is arranged to engage the seat 634 of the improved bypass valve which is formed in a first motor component 632 around an opening of the refrigerant return passage 140 . In this embodiment, the seat 634 of the bypass valve has a substantially conical concave shape which matches the known convex shape of the lateral surface 630 of the bypass valve plate 628. During the operation of the thermostat 600, and especially during a period of heating transition of the refrigerant flow, the plate 628 of the bypass valve is pushed towards the seat 634 of the bypass valve, as described. The vibrations described above for the thermostat 100 in FIG. 1 can be advantageously avoided with the use of the plate 628 of the improved bypass valve. The tapered side surface 630F acts to relieve the pressure differentials that cause the vibrations through the plate 628 of the bypass valve, and eliminate
effectively vibrations and increase the service life of the thermostat 600 compared to the service life of the thermostat 100. In this mode, a pressure damping passage is created between the intake opening 136, through a passage 636 which exists between the plate 628 of the bypass valve and the seat 634 of the bypass valve, and outside the return passage 140 of the refrigerant. At the moments when the plate 628 of the bypass valve is near or approaching the seat 634 of the bypass valve, there is a uniform flow area around the entire periphery of the plate 628 of the bypass valve in the passage 638. The uniform flow area in passage 636 acts to promote efficient flow of refrigerant therethrough, and advantageously is more effective to dampen pressure pulsations that would otherwise cause vibrations to the bypass valve plate, in the moments when the plate 628 of the bypass valve is transitioning to a closed position and is near and almost seated on the grip 634 of the bypass valve. An alternative embodiment for a thermostat 800 having a pressure damping passage is shown in cross section in FIG. 8 and FIG. 9. The thermostat
800 has similar characteristics and elements with the thermostat 100, and for simplicity, the common elements are called using the same reference numbers. The thermostat 800 has an intake opening 136, a discharge opening 140, and a radiator discharge opening 144. The thermostat 800 has an improved bypass valve plate 828, and an improved valve seat 834. The plate 828 of the bypass valve is connected to the bypass valve retainer 126, and operates in a manner substantially similar to the bypass valve plate 28 shown in FIG. 1.
The plate 828 of the bypass valve has an improved side surface 830. The lateral surface 830 has a convex conical profile for the most part and is arranged to be brought into linear contact with the seat 834 of the bypass valve which is formed in a first component 832 of the motor around an opening of the return passage 140 of the refrigerant. The seat 834 of the bypass valve is formed as a marked transition, at approximately 90 degrees, and has little or no finish that contacts the side surface 830 in a flat manner. The seat 834 of the bypass valve can be described as a "sharp" edge surrounding the opening for the passage 140 that contacts the side surface 830 along a
line . During the operation of the thermostat 800, and especially during a period of heating transition of the refrigerant flow, the plate 128 of the bypass valve is pushed towards the seat 834 of the bypass valve, as described. The vibration described above for the thermostat 100 in FIG. 1, advantageously can be avoided with the use of plate 828 of the improved bypass valve. Conical surface 830 acts to relieve pressure differentials that cause vibration through plate 828 of the bypass valve and effectively eliminate vibration and increases service life of thermostat 800 compared to the service life of the thermostat 100. In this embodiment, a pressure damping passage is created between the intake opening 136, through a passage 836 that exists between the bypass valve plate 828 and the bypass valve seat 834, outside the return passage 140 of the refrigerant. At the moments when the plate 828 of the bypass valve is near and approaching the seat 834 of the bypass valve, there is an area of high turbulence about the entire periphery of the plate 828 of the bypass valve in the passage 836. The flow area for the fluid that passes through
of passage 836 acts to destroy all pressure differentials existing through plate 828 of the bypass valve by altering all pressure waves with turbulence created by an edge flow condition close to the marked transition of the seat or the edge 834. This configuration is advantageously more effective for damping pressure pulsations that would otherwise cause vibrations to the bypass valve plate at times when the bypass valve plate 828 is transitioning to a closed position and it is near or almost seated on the seat 834 of the bypass valve. The present invention can be incorporated into other specific forms, without departing from its spirit or its essential characteristics. The described modalities should be considered in all aspects only as illustrative and not as restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that are within the meaning and range of equivalence of the claims must be covered within its scope.