Cylinder head cooling system

The present invention relates to a cooling system for an engine, and more particularly to a liquid cooling system for a cooling cylinder head of a motorcycle.

The engine (internal combustion engine) used in a motorcycle is typically air-cooled or water-cooled. Air-cooled engines rely on the flow of air over heat-conducting surfaces such as fins that cool the engine. A water-cooled engine uses the flow of liquid (eg, refrigerant or oil) in the engine to absorb heat from the engine, and uses a heat exchanger such as a radiator to absorb the heat in the liquid. To the air.

<p><patcit num="1"><text>U.S. Pat. No. 4,714,508</text></patcit></p>

<p num="0004"> In one embodiment, the invention has a pair of cylinders arranged in a "V" shape that converges towards the crankshaft axis and defines a space between the cylinders in the upper range of each cylinder. Provide cylinder heads for motorcycle engines. The cylinder head includes a base configured to be coupled to one of the cylinders, an intake passage and an intake valve movably located in the intake passage, and the intake is configured to be located closer to the space. Includes a side and an exhaust side that includes an exhaust passage and an exhaust valve that is movably located within the exhaust passage and is configured to be located on a side away from the space. The cooling liquid inlet port and the cooling liquid discharge port are arranged on the intake side. The cooling liquid passage passes through the cylinder head and reduces the operating temperature of the cylinder head.</p><p num="0005"> In another embodiment, the present invention is a cylinder head for a motorcycle engine, on the intake side having an intake passage where an intake valve is located, on the exhaust side having an exhaust passage where an exhaust valve is located, and on the intake side. Provided is a cylinder head for a motorcycle engine including a cooling liquid inlet port arranged and a cooling liquid exhaust port arranged on the intake side. The exhaust passage has a curvature. The cylinder head also includes a liquid cooling passage that extends between the inlet and outlet ports. The liquid cooling passage includes a single loop passage having a measurable length. A portion of the liquid cooling passage substantially follows the curvature of the exhaust passage for a rotation of at least 270 degrees.</p><p num="0006"> In yet another embodiment, the invention is a motorcycle, the frame, the engine coupled to the frame, and the left and right extending laterally outward from the frame and coupled to the frame in front of the engine. Includes an engine guard, left and right leg shields that are coupled to the left and right engine guards, a liquid cooling circuit that communicates with the engine, and left and right radiators that communicate with the liquid cooling circuit and are located in the left and right leg shields, respectively. , Provides motorcycles. In some configurations, the air passing through the left and right radiators is directed away from the motorcycle by the left and right air ducts located in the lower left and right respectively.</p><p num="0007"> Other aspects of the invention will become apparent by considering the detailed description and accompanying drawings.</p>

<figref num="1">A side view of a motorcycle according to an embodiment of the present invention.</figref><figref num="2">The front view of a part of the motorcycle of FIG. 1 showing the left and right engine guards, the left and right leg shields or the "bottom" of the motorcycle.</figref><figref num="3">A rear view of a portion of the motorcycle of FIG. 2, including a regirator assembly located in the lower left and right, and a liquid cooling circuit.</figref><figref num="4">Side view of the liquid cooling circuit and engine of the motorcycle of FIG. 1 with the leg shield removed.</figref><figref num="5">Front view of the liquid cooling circuit of FIG. 4 with the engine removed.</figref><figref num="6">Top view of the liquid cooling circuit of FIG.</figref><figref num="7">FIG. 5 is a perspective view of the liquid cooling circuit of FIG.</figref><figref num="8">An exploded perspective view of a part of the engine of FIG. 4, illustrating a front cylinder, a front gasket, and a front cylinder head.</figref><figref num="9">The rear view of the front cylinder head of FIG. 8 which shows the intake side of the front cylinder head.</figref><figref num="10A">FIG. 8 is a perspective view of the front cylinder head of FIG. 8 showing a liquid cooling passage.</figref><figref num="10B">FIG. 2 is a cross-sectional view taken along lines 10B-10B in FIG. 10A, illustrating a portion of the liquid cooling passage surrounding the exhaust passage of the front cylinder head.</figref><figref num="10C">FIG. 5 is a cross-sectional view taken along lines 10C-10C in FIG. 10A, illustrating a substantially circular cross section of a straight portion of the liquid cooling passage.</figref><figref num="10D">FIG. 5 is a cross-sectional view taken along lines 10D-10D in FIG. 10A, illustrating a substantially circular cross-section of the connection of the liquid cooling passages.</figref><figref num="11">The bottom view of the front cylinder head of FIG. 8 illustrating an opening exposed on the base of the front cylinder head.</figref><figref num="12">FIG. 10A is a perspective view of a core used in the manufacture of the liquid cooling passage and front cylinder head of FIG. 10A.</figref><figref num="13">FIG. 5 is a schematic view of the liquid cooling circuit of FIG. 5 illustrating the operation of the first state in which the liquid refrigerant bypasses the radiator coil of the radiator assembly.</figref><figref num="14">FIG. 13 is a schematic diagram similar to FIG. 13, illustrating the operation of the second state in which the liquid refrigerant flows through the radiator coil.</figref><figref num="15">A front perspective view of a part of the motorcycle of FIG. 2 showing the lower left and right sides.</figref><figref num="16">The rear perspective view of the lower left and right of FIG.</figref><figref num="17">Exploded view of the lower right of FIG.</figref><figref num="18">FIG. 5 is a cross-sectional view taken along line 18-18 of FIG.</figref><figref num="19">FIG. 5 is a cross-sectional view taken along line 19-19 of FIG. 15, illustrating the direction of air flow through the lower right section.</figref>

Before elaborating on the embodiments of the present invention, it should be understood that the present invention is limited in its use to the details of the structure and arrangement of the parts illustrated in the drawings or given the following description. Not. The present invention can be implemented in other embodiments and can be realized or implemented in various aspects. It should also be understood that the technical terms or terms used herein are for explanatory purposes and should not be considered limiting. The use of "include", "provide", "have" and their variants herein is used with the intent of including additional items as well as the items listed below and their equivalents. Unless otherwise specified or limited, the terms "mounted", "connected", "supported" and "combined" and their variants are used in a broad sense and are used in a broad sense, both direct and indirect. Includes connection, support, and coupling. Furthermore, "connected" and "combined" are not limited to physical or mechanical connections and connections.

FIG. 1 shows a motorcycle 10. The illustrated motorcycle 10 is a touring motorcycle 10, a frame 12, a front wheel 18 coupled to the frame 12 via a steering assembly 16, and a frame 12 via a swing arm assembly (not shown). Includes a rear wheel 18 coupled to. The motorcycle 10 is an engine 20 coupled to the frame 12 and includes an engine 20 operably coupled to the rear wheels 18 via a transmission 22.

With reference to FIGS. 2 and 3, the frame 12 includes a steering head 24 and two down tubes 26 extending downward from the steering head 24 at the front end of the frame 12. The motorcycle 10 includes an engine guard 28 coupled to the down tube 26. The engine guard 28 includes a top bar 30, a left sidebar 3, a right sidebar 32 and a lower portion 36. The lower portion 36 includes a left flange 38 at the lowermost end of the left sidebar 32, a right flange 40 at the lowermost end of the right sidebar 34, and further includes a connecting portion 42 between the left and right flanges. The top bar 30 is connected to the upper portion of the down tube 26, and the left and right flanges 38 and 40 are connected to the lower portion of the down tube 26 (for example, the position where the foot peg or foot control is mounted on the frame 12). The engine guard 28 protects the motorcycle 10 from coming into contact with the ground in the unlikely event that the motorcycle 10 lights up.

The motorcycle 10 has left and right side fairings (or "lowers") coupled to the engine guard 28 so that the lower parts 44L and 44R are respectively located on the respective sides of the central surface C of the motorcycle 10. ) Includes 44L and 44R. As used herein, each reference code containing "L" identifies a structure located on the left side of the motorcycle 10 (from the perspective of the rider sitting on the motorcycle 10) and each corresponding reference code containing R. Identify a structure located on the right side of the motorcycle 10. The lower 44L, 44R are located approximately in front of the area occupied by the rider's feet and assist in blocking wind from the rider's skin and feet during the ride. Each lower 44L, 44R includes front panels 170L, 170R having upper parts 46L, 46R, outer parts 48L, 48R, inner parts 50L, 50R, lower parts 52L, 52R, and central parts 54L, 54R (FIG. 2). .. Further, each front panel 170L, 170R includes a forward facing surface 56L, 56R and a rear facing surface 58L, 58R. The front panels 170L and 170R are substantially concave so that the rear facing surfaces 58L and 58R define the cavities 174L and 174R (FIG. 3). Each central portion 54L, 54R includes holes 60L, 60R covered by screens 62L, 62R. Each inner portion 50L, 50R includes vents 64L, 64R rotating about a substantially vertical axis, and the rider adjusts the vents 64L, 64R to control and direct the amount of air passing between the lower 44L, 44R. Make it possible.

The lower left and right lower parts 44L and 44R are mirror images that are substantially the same as each other. The installation of the lower right 44R on the right side of the engine guard 28 will be described in detail. The attachment of the lower left 44L to the left side of the engine guard 28 is not described, but it is attached in a manner similar to that of the lower right 44R. The forward facing surface 56R of the lower right 44R along the outer portion 48R includes an outer surface shape that forms a recess that receives the right sidebar 34. The lower right 44R also includes an upper portion cover 66R that is fastened to the upper portion 46R and captures the portion of the top bar 30 between the outer surface shape of the upper portion 46R and the upper portion cover 66R. The configuration of the lower right 44R allows the lower right 44R to be nested within the right side of the engine guard 28. In addition to this, the lower right 44R is attached to the engine guard 28 by U-bolts and straps at various positions.

FIG. 4 illustrates an engine 20, which is a V-type engine including front and rear cylinders 68F, 68R and corresponding front and rear cylinder heads 70F, 70R. As used herein, each reference code including "F" refers to the structure associated with the front cylinder 68F and front cylinder head 70F, and each corresponding reference code containing "R" refers to the rear cylinder 68R and rear. Refers to the structure related to the cylinder head 70R. Each cylinder 68F, 68R includes a reciprocating piston (not shown), and each of the cylinder heads 70F, 70R has an intake valve 72F, respectively, to control the flow of intake and exhaust air through their respective combustion chambers. Includes 74R and exhaust valves 74F, 74R. The cylinders 68R and 68R (and the pistons therein) converge toward the crankshaft shaft A at the lower part of the engine 20 and gradually increase upward between the cylinder heads 70F and 70R and between the cylinders 68F and 68R. Create space S. The cylinders 68F and 68R include cooling fins and are air-cooled. Cylinder heads 70F, 70R include internal liquid cooling passages 76F, 76R and air-cooled fins, which are described in detail below.

The motorcycle 10 includes a liquid cooling system 78 that circulates liquid through the liquid cooling passages 76F and 76R of the cylinder heads 70F and 70R in order to remove the heat of combustion from the cylinder heads 70F and 70R. The liquid cooling system 78, or liquid cooling circuit, best shown in FIG. 4-7, is a pump 80, a supply header 82, a pair of supply branch lines 84, a liquid cooling passage 76F, 76R, a pair of return branches. It includes a line 86, a return header 88, and a thermostat valve 90, all connected in series. The liquid cooling system 78 also includes a radiator supply line 92, a right radiator assembly 94R, a radiator crossover line 96, a left radiator assembly 94L and a radiator return line 98, all of which are connected in series with the thermostat valve 90. ..

The radiator assemblies 94L and 94R include radiator coils 100L and 100R, exhaust manifolds 102L and 102R defining the low temperature side of the radiator coils 100L and 100R, and fans 106L and 106R near the rear surface of the radiator coils 100L and 100R. including. The radiator assemblies 94L, 94R are coupled to the lower 44L, 44R, respectively. Specifically, the right radiator assembly 94R is located in the cavity 174R of the lower right 44R and covers the hole 60R from the rearward side of the lower right 44R. The left radiator assembly 94L is located in the cavity 174L of the lower left 44L and covers the hole 60L from the rearward facing side of the lower left 44L. The radiator assemblies 94L and 94R are attached to the lower parts 44L and 44R with screw fasteners, and the screw fasteners are screwed to the mounting bosses on the lower parts 44L and 44R.

The pump 80 and the thermostat valve 90 are coupled and supported by the lower portion 36 of the engine guard 28. The pump 80 is located between the left and right lower parts 44L and 44R at a height substantially lower than the left and right radiator coils 100L and 100R when the motorcycle 10 is in the upright position (FIG. 5). The pair of supply branch lines 84 and the pair of return branch lines 86 are substantially entirely arranged in the space S of the V-twin engine 20 (FIG. 4).

The liquid cooling system 78 also has a fill neck 110 and a pressure cap 108 communicating with the inlet manifold 104R of the right radiator assembly 94R, a fill cap 114 and an overflow bottle 112 communicating with the pressure cap 108, and an overflow bottle 112 and the atmosphere. Includes an overflow tube 116 with communication. The liquid cooling system 78 also includes a drain plug 118 on the inlet manifold 104L of the left radiator assembly 94L.

FIG. 8-11 illustrates the front cylinder head 70F. The rear cylinder head 70R is substantially the same as the illustrated front cylinder head 70F, except that it is a mirror image of the rear cylinder head 70R. The cylinder head 70F is configured to face the corresponding cylinder 68F of the engine 20 and is coupled to the corresponding cylinder 68F to define the combustion chamber 122F (FIG. 11). The cylinder head 70F further includes an intake side 124F and an exhaust side 126F. The intake side 124F includes an intake passage 128F and an intake valve 78F arranged in the intake passage 128F and movable therein. The exhaust side 126F of the head 70F includes an exhaust passage 130F and an exhaust valve 74F arranged in the exhaust passage 130F and movable therein. The intake valve 78F selectively provides the intake air from the intake passage 128F into the combustion chamber 122F, and the exhaust valve 74F selectively releases the combustion exhaust gas from the combustion chamber 122F to the exhaust passage 130F. The heat from the combustion process tends to heat the cylinder head 70F, especially in the area around the combustion chamber 122F and the exhaust passage 130F.

As best shown in FIG. 10A, the liquid cooling passage 76F extends from the inlet port 132F to the exhaust port 134F through the cylinder head 70F. The cooling passage 76F extends in a single loop from the inlet port 132F of the intake side 124F of the head 70F around the exhaust passage 130F, and returns to the exhaust port 134F of the intake side 124F of the head 70F. The liquid is circulated in or through the cylinders 68F, 68R, whatever. Therefore, only the cylinder heads 70F and 70R of the engine 20 are directly cooled by the liquid, while the cylinders 68F and 68R are strictly cooled by the air. Further, the cylinder heads 70F and 70R are designed so as to be accurately cooled in the area around the exhaust passages 130L and 130R. The cooling passage 76F does not extend throughout the cylinder head 70F, but mainly extends around the exhaust passage 130F. The cooling passage 76F has a focused path and defines a measurable length through which the liquid flows. That is, the cooling passage 76F is formed of a conduit having a substantially symmetrical cross section, and the conduits together define a longitudinal axis (not shown) that follows the center of the cooling passage 76F, and the length of the longitudinal axis is , Can be measured. This is in contrast to the prior art cooling passages, which are defined by freely shaped cavities and do not intuitively define the longitudinal axis, path or length.

With reference to FIG. 8-11 again, the inlet and exhaust ports 132F and 134F are arranged on the intake side 124F of the cylinder head 70F. The inlet and exhaust ports 132F and 134F are visible on the cylinder head 70F from the rear (FIG. 9) of the motorcycle 10 with a line of sight perpendicular to the front (or conversely, the inlet and exhaust ports 132F and 134F are automatic. It is visible on the rear cylinder head 70R from the front to the rear of the motorcycle 10 with a right-angled line of sight). The inlet and exhaust ports 132F and 134F each define a port shaft (not shown) that exits the port in the rear direction, and the inlet and exhaust ports 132R and 134R of the rear cylinder head 70R each have a port in the front direction. Define the exit port axis (not shown). The inlet and exhaust ports 132F and 134F are separated from the plane P defined by the base of the cylinder head 70F. The inlet and exhaust ports 132F and 134F are located on the respective sides of the inlet passage 128F.

As shown in FIGS. 10A and 10B, the cooling passage 76F extends from the end of the first substantially straight portion 136F extending from the inlet port 132F into the cylinder head 70F and the end of the first linear portion 136F. A horseshoe-shaped portion 138F to connect to a substantially horseshoe-shaped portion 138F that follows the curvature of the exhaust passage 130F at at least an angle B (for example, a rotation of 270 degrees) to substantially surround the exhaust passage 130F and to the exhaust port 134F. Includes a second straight section 140F extending from the horseshoe-shaped section 138F along the straight path. The connection section 142F communicates the horseshoe-shaped portion 138F with the interconnection of the first straight portion 136F and the second straight portion 140F. The connecting section 142F passes through the bridge portion 144F of the cylinder head 70F between the intake passage 128F and the exhaust passage 130F, and the connecting section 142F has a reduced diameter compared to the rest of the cooling passage 76F (FIG. 10C and 10D). The liquid cooling passage 76F has a substantially circular cross section along a substantially total length thereof.

As shown in FIGS. 8 and 11, the intermediate portion of the horseshoe-shaped portion 138F breaks the surface of the base 120F and defines an opening 146F that exposes a portion of the liquid cooling passage 76F. The opening 146F is covered by a gasket 148F sandwiched between the base 120F of the cylinder head 70F and the deck 150F of the cylinder 68F when the engine 20 is assembled. The gasket 148F prevents leakage of the cooling fluid from the opening 146F.

With reference to FIGS. 10A and 12, the cylinder head 70F is manufactured by a casting process using a core to define and form internal passages such as intake and exhaust passages 128F, 130F. Further, the core 152F (FIG. 12A) is used to form the cooling passage 76F. The core 152F is fixed in the casting block or tool so that the core remains fixed during the casting and cooling process. The core has three legs. The first and second legs are located at the ends of the straight section and the third leg 154F is located at the base of the horseshoe-shaped section 138F. The third leg 154F creates an opening 146F during the casting process. After the cylinder head 70F is cast, the core is removed with water or chemicals.

As shown in FIGS. 5-7, 13 and 14, the refrigerant supply header 82 extends from the space S between the cylinders 68F and 68R. The refrigerant supply header 82 is divided into a pair of supply branch lines 84 connecting the cooling passages 76F and 76R of the cylinder heads 70F and 70R to the liquid cooling system 78. The discharge ports 134F and 134R supply liquid refrigerant from the cylinder heads 70F and 70R of the pair of return lines 86, and both flow to the refrigerant return header 88. All of the inlet ports and discharge ports 132F, 132R, 134F, 134R of the cylinder heads 70F and 70R are simplified types for connecting and / or not connecting to the supply branch line 84 and the return branch line 86 without the use of tools. Provide a connecting joint. Inlet port 132F, 132R and discharge ports 134F, 134R are all are positioned near the space S Runode (as shown in FIG. 4, since it is located in the "V" of the engine 20), the supply and return headers 82 , 86 need only be turned to a single position. That is, the inlet port and the discharge port 132F, 132R, 134F, 134R are arranged on the intake side 124F, 124R located near the space S.

During operation, the cooling system 78 operates to circulate the liquid through the cylinder heads 70F, 70R to cool the cylinder heads 70F, 70R. As shown in FIG. 13, in the first operation mode when the temperature of the liquid is lower than the threshold temperature, the pump 80 supplies the liquid to the supply header 82, the supply branch line 84, the cooling passages 76F, 76R, and the return branch line. 86, the return header 88 is circulated to the first valve inlet 156 of the thermostat valve 90. Due to the temperature of the liquid being below the threshold temperature, the valve 90 is in the first position, allowing the liquid to flow through the valve 90 through the first valve outlet 158 and back to the pump 80. In the first mode, the thermostat bypasses the left and right radiator assemblies.

The second mode of operation is shown in FIG. This mode of operation occurs when the temperature of the liquid is above the threshold temperature. In the second mode, the pump 80 delivers the liquid to the first valve inlet 156 of the thermostat valve 90 via the supply header 82, the supply branch line 84, the cooling passages 76F, 76R, the return branch line 86, and the return header 88. Circulate. Due to the temperature of the liquid being above the threshold temperature, the valve 90 is in the second position, allowing the liquid to flow out of the second valve outlet 160 through the valve 90. From the second valve outlet 160, the fluid passes through the radiator supply line 92, the inlet manifold 104R, the radiator coil 100R, the discharge manifold 102R of the right radiator assembly 94R, the radiator crossover line 96, the inlet manifold 104L, and the radiator coil 100L. The thermostat valve 90 is oriented so that the second valve inlet 162 returns. The second valve inlet 162 directs the liquid to the first valve outlet 158 that returns to the pump 80. In the second mode of operation, the fans 160L, 160R are rotated, air is drawn through the radiator coils 100L, 100R, and the heat from the liquid in the radiator coils 100L, 100R is transferred to the air passing therethrough. Assist.

With reference to FIGS. 15-17, the lower 44L, 44R is such that the rear facing surfaces 58L, 58R of the front panels 170L, 170R are covered to define the cavities 174L, 174R that house the radiator assemblies 94L, 94R. Includes rear panels 164L, 164R coupled to front panels 170L, 170R. Further, the rear panels 164L, 164R include accommodation covers 166L, 166R that cover and selectively provide access to the accommodation cavities 176L, 176R in the lower 44L, 44R. The accommodating cavities 176L and 176R are arranged above the cavities 174L and 174R and are sealed from the cavities 174L and 174R. The rear panels 164L, 164R also define ducts 172L, 172R for air exiting the radiator assemblies 94L, 94R. The ducts 172L and 172R direct the air away from the motorcycle 10 in the outward direction so that the air is directed downward and away from the rider's shin and the motorcycle. FIG. 17 shows the right rear panel 164R and the right accommodation cover 166R related to the liquid cooling system 78. FIG. 17 also shows adapters 168L, 168R fitted between the left and right screens 62L, 62R and the left and right radiator assemblies 94L, 94R.

18 and 19 show the configuration of the right radiator assembly 94R in the cavity 174R formed in the lower right 44R. The arrows illustrated by the virtual lines in FIGS. 16 and 19 more clearly show the path that air takes as it passes through the right radiator assembly 94R, enters the cavity 174R, and exits through duct 172R.

During use, the duct 172R redirects the airflow away from the rider and expels the air to a low pressure, high speed airflow position. The duct 172R is designed to minimize constraints on airflow while maintaining clearance for the rider's lower legs, feet and motorcycle controls (eg, rear brake pedals, shift levers). The duct 172R is positioned to discharge heated air into a relatively low pressure and high speed flow region of the air flow around the vehicle. The duct 172R allows the heated air to be carried away from the rider by the wake airflow around the bike with minimal recirculation in the left and right lower 44L, 44R directions. The duct also improves the performance of air flow through the radiator due to the larger pressure difference between the air duct inlet and outlet.