Double-circulation cooling system of parallel double-cylinder engine

Abstract

The invention discloses a double-circulation cooling system of a parallel double-cylinder engine. The double-circulation cooling system comprises an oil cooling system and a water cooling system. The oil cooling system comprises a first lubricating oil way and a second lubricating oil way. The water cooling system comprises an inner circulation system and an outer circulation system, when the temperature of the cooling liquid in the engine cylinder body is lower than a preset first temperature threshold value, the inner circulation system is started, and the outer circulation system is closed, and when the temperature of the cooling liquid in the engine cylinder body is higher than the preset first temperature threshold value and lower than a preset second temperature threshold value, the inner circulation system is started; the inner circulation system and the outer circulation system are both started; and when the temperature of the cooling liquid in the engine cylinder body is higher than a preset second temperature threshold value, the outer circulation system is started, and the inner circulation system is closed. According to the dual-circulation cooling system, different cooling circulation systems are started for different temperature states of the engine, and the engine can exert the optimal stable performance through the coupling design of the water cooling system and the oil cooling system.

Description

Technical Field

[0001] The invention relates to an engine cooling system, more specifically, to a dual-circulation cooling system for a parallel twin-cylinder engine. Background Art

[0002] The engine oil temperature and cylinder temperature represent the engine temperature. If the temperature is too low, the engine combustion efficiency will be low, the power will drop, and the fuel consumption will increase. If the temperature is too high, the oil viscosity will decrease, the lubricating oil film on the cylinder wall will be destroyed, the lubrication performance will be reduced, and the reliability of engine parts will be reduced, and even early combustion and knocking problems will be caused, which will damage the normal operation of the engine. Therefore, how to maintain the temperature of the engine within the optimal operating temperature range is a key technology to ensure that the engine can achieve its maximum performance and reliable stability, and it has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0003] Based on this, it is necessary to provide a dual-circulation cooling system for a parallel twin-cylinder engine to address the above technical problems.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions: A water cooling system, the water cooling system comprising an internal circulation system and an external circulation system, the internal circulation system acting on the inside of an engine assembly, the external circulation system acting on the outside of the engine assembly, the engine assembly comprising an engine body, When the temperature of the coolant inside the engine body is lower than a preset first temperature threshold, the internal circulation system is turned on and the external circulation system is turned off. When the temperature of the coolant inside the engine body is higher than a preset first temperature threshold and lower than a preset second temperature threshold, both the internal circulation system and the external circulation system are turned on; When the temperature of the coolant inside the engine body is higher than a preset second temperature threshold, the external circulation system is turned on and the internal circulation system is turned off. Wherein, the first temperature threshold and the second temperature threshold are set by a thermostat in the engine body.

[0005] As a preferred embodiment of the present invention, the thermostat includes a thermostat bypass valve, a thermostat main valve, a thermostat valve core and a thermostat compression spring. The thermostat main valve controls the on-off of the external circulation system, and the thermostat bypass valve controls the on-off of the internal circulation system.

[0006] As a preferred embodiment of the present invention, the first temperature threshold is 79°C, and the second temperature threshold is 95°C.

[0007] As a preferred embodiment of the present invention, a water temperature sensor is provided in the engine assembly, and the water temperature sensor monitors the temperature of the coolant inside the engine body.

[0008] As a preferred embodiment of the present invention, when the internal circulation system is turned on, the coolant flows into the engine body through the water pump outlet pipe under the action of the water pump assembly. After heat exchange, the coolant flows out from the cylinder head arranged on the engine body. The coolant flows to the engine internal circulation water pipe through the thermostat bypass valve and then flows back to the water pump assembly. At the same time, the coolant flowing out of the water pump assembly flows into the interior of the oil cooler through the oil cooler inlet pipe and cools it. The coolant flows into the water pump inlet pipe through the oil cooler outlet pipe and the tee and then flows back to the water pump assembly. When the external circulation system is turned on, the coolant flows into the water tank radiator assembly through the engine external circulation water pipe, and the fan motor assembly works to cool the water tank radiator assembly quickly.

[0009] A dual-circulation cooling system for a parallel twin-cylinder engine, characterized in that the dual-circulation cooling system for the parallel twin-cylinder engine comprises an oil cooling system and a water cooling system as described in any one of claims 1 to 5.

[0010] As a preferred embodiment of the present invention, the oil cooling system comprises a first lubricating oil circuit and a second lubricating oil circuit. The first lubricating oil circuit includes a main oil pump, which pumps the oil to the oil inner circulation pipe on the upper crankcase assembly, and enters the first branch where the crankshaft assembly is located, the second branch where the balance shaft assembly is located, and the third branch where the cylinder head camshaft component is located through the main oil channel hole on the upper crankcase assembly, and then flows back to the oil pan assembly after passing through the engine body. The second lubricating oil circuit comprises an auxiliary oil pump and an oil pump filter assembly. The auxiliary oil pump pumps the oil in the oil pan assembly into the oil cooler. The oil flows back to the main oil pump after passing through the lower crankcase cover assembly, the lower crankcase assembly, the upper crankcase assembly, and the oil filter assembly.

[0011] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a parallel twin-cylinder engine dual-circulation cooling system, which activates different cooling circulation systems for different temperature states of the engine. When the temperature is low, the small circulation system is activated, the water flow is small, the cooling effect is weak, the temperature rise time of the engine is shortened, and it is helpful for the engine to reach the normal working temperature as soon as possible, and the combustion efficiency is improved. When the temperature is too high, the large circulation system is activated, the water flow is large, and the fan motor is controlled to work through the temperature control switch, the heat is quickly dissipated, and the temperature of the engine can be quickly reduced to the normal working temperature. When the temperature is within the normal working temperature range of the engine, the internal and external circulations work simultaneously to maintain the normal cooling and heat dissipation balance state of the engine. At the same time, through the coupling design of the water cooling system and the oil cooling system, the engine oil temperature and the coolant temperature can be maintained within the optimal working temperature range, so that the engine can exert the best stable performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the scheme of the present invention, a brief introduction is given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0013] Figure 1 is a schematic diagram of a dual-circulation cooling system of the present invention; Figure 2 is a schematic diagram of the circulation of the oil cooling system of the double-circulation oil cooling system of the present invention; Figure 3 It is a schematic diagram of the circulation of the water cooling system of the double-circulation water cooling system of the present invention; Figure 4 is a schematic diagram of a first lubricating oil circuit of the oil cooling system of the present invention; Figure 5 is a schematic diagram of a second lubricating oil circuit of the oil cooling system of the present invention; Figure 6 It is a schematic structural diagram of the water cooling system of the present invention; Figure 7 yes Figure 6 A partial schematic diagram of the water cooling system structure; Figure 8 Schematic diagram of the working of the water cooling system of the present invention, which is in the internal circulation state at this time; Fig. 9 Schematic diagram of the working of the water cooling system of the present invention, in which the internal and external circulations coexist; Fig.10 Schematic diagram of the working of the water cooling system of the present invention, which is in the external circulation state at this time; The markings in the figure are as follows: 100-engine assembly; 101-starting motor; 102-Start the deceleration component; 103-overrunning clutch assembly; 104-crankshaft assembly; 105-magneto assembly; 106- crankshaft position sensor; 107- cylinder water inlet; 108-Balance shaft assembly; 109-water pump assembly; 1091- main water inlet of water pump; 1192-water pump secondary water inlet; 110-water pump outlet pipe; 111-oil cooler water inlet pipe; 112-Oil cooler; 113-water temperature sensor; 114-Thermostat; 1141-Thermostat bypass valve; 1142-thermostat main valve; 1143-Thermostat valve core; 1144-Thermostat compression spring; 115- Engine internal circulation water pipe; 116-Thermostat cover; 117-lower crankcase cover assembly; 118-Oil filling plug; 119-cylinder head cover; 120- cylinder head camshaft components; 121- cylinder assembly; 122-upper crankcase assembly; 123-lower crankcase assembly; 124-Oil pump chain assembly; 125-Oil pump driven sprocket; 126-oil pump assembly; 127-Oil filter assembly; 128-engine oil internal circulation pipe; 129-Oil filter assembly; 130-oil return pipe; 131-Oil pan assembly; 132-Oil pump oil filter assembly; 133-left cover assembly; 134-engine body; 200-Vehicle control system; 300-Water cooling system; 301-water tank radiator assembly; 302-Fan motor assembly; 303-water tank outlet hose; 304-water tank outlet hard pipe; 305- three-way water inlet pipe; 306-tee connector; 307-water pump inlet pipe; 308-oil cooler water outlet pipe; 309-water tank inlet hose; 310-water tank water inlet hard pipe; 311-Engine external circulation water pipe; 312-Fan temperature control switch. DETAILED DESCRIPTION

[0014] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0015] like Figure 1 , Figure 2 and Figure 3 As shown, the dual-circulation cooling system of a parallel twin-cylinder engine according to an embodiment of the present application includes: an engine assembly 100, a vehicle control system 200 and a water cooling system 300.

[0016] The engine assembly 100 includes a starter motor 101, a starter reduction component 102, an overrunning clutch assembly 103, a crankshaft assembly 104, a magneto assembly 105, a crankshaft position sensor 106, a cylinder water inlet 107, a balance shaft assembly 108, a water pump assembly 109, a water pump outlet pipe 110, an oil cooler water inlet pipe 111, an oil cooler 112, a water temperature sensor 113, a thermostat 114, an engine internal circulation water pipe 115, a thermostat cover 116, and a lower crankcase cover assembly. 117, oil port filling plug 118, cylinder head cover 119, cylinder head camshaft component 120, cylinder block assembly 121, upper crankcase assembly 122, lower crankcase assembly 123, oil pump chain assembly 124, oil pump driven sprocket 125, oil pump assembly 126, oil filter assembly 127, oil internal circulation pipe 128, oil filter assembly 129, oil return pipe 130, oil pan assembly 131, oil pump filter assembly 132, left cover assembly 133, engine body 134.

[0017] The engine body 134 includes a cylinder head camshaft component 120 , a cylinder block assembly 121 , an upper crankcase assembly 122 , and a lower crankcase assembly 123 .

[0018] It should be noted that the starting motor 101, the starting deceleration component 102, the crankshaft assembly 104, the cylinder water inlet 107, the balance shaft assembly 108, the water temperature sensor 113, the thermostat 114, the thermostat cover 116, the lower crankcase cover assembly 117, the oil port oil filling plug 118, the cylinder head cover 119, the oil pump assembly 126, the oil filter assembly 127, the oil internal circulation pipe 128, the oil return pipe 130, the oil pan assembly 131, and the left cover assembly 133 are arranged on the engine body 134.

[0019] In addition, the crankshaft assembly 104 is arranged in parallel with the balance shaft assembly 108. The overrunning clutch assembly 103 and the magneto assembly 105 are arranged on the crankshaft assembly 104. The water pump assembly 109 is arranged on the balance shaft assembly 108 and rotates synchronously. The water pump assembly 109 is provided with a water pump main water inlet 1091 and a water pump secondary water inlet 1092. The water pump outlet pipe 110 is arranged on the water pump assembly 109 and connected to the cylinder water inlet 107.

[0020] In addition, the oil cooler water inlet pipe 111 is arranged on the water pump assembly 109 and connected to the oil cooler 112. The oil cooler 112 is arranged on the lower crankcase cover assembly 117. The crankshaft position sensor 106 is arranged on the left cover assembly 133 to monitor the position of the crankshaft assembly 104.

[0021] In addition, the engine internal circulation water pipe 115 is arranged on the water pump assembly 109 and is connected to the thermostat 114 through the cylinder head camshaft component 120 .

[0022] The oil pump assembly 126 is provided with a main oil pump 1261 , an auxiliary oil pump 1262 and an oil pump driven sprocket 125 , and is connected to the crankshaft assembly 104 via an oil pump chain assembly 124 .

[0023] The oil filter assembly 129 is disposed on the left cover assembly 133 to filter the oil for lubrication of the crankshaft assembly 104 , the balance shaft assembly 108 and the camshaft.

[0024] The oil pump filter assembly 132 is disposed on the oil pump assembly 126 to pump the oil stored in the oil pan assembly 131 into the engine body 134 for recycling.

[0025] The water cooling system 300 includes: a water tank radiator assembly 301, a fan motor assembly 302, a water tank water outlet hose 303, a water tank water outlet hard pipe 304, a three-way water inlet pipe 305, a three-way joint 306, a water pump water inlet pipe 307, an oil cooler water outlet pipe 308, a water tank water inlet hose 309, a water tank water inlet hard pipe 310, an engine external circulation water pipe 311, and a fan temperature control switch 312; The oil cooling system of the dual-circulation cooling system is further explained below.

[0026] like Figure 1 and Figure 2 As shown, after the engine is filled with oil as required, it is powered on and started, and the oil is divided into two paths for lubrication, cooling and recycling. Among them, the first lubricating oil path Y1 of the oil cooling system pumps the oil to the oil internal circulation pipe 128, the left cover assembly 133, the oil filter assembly 129 and the box body through the main oil pump 1261, and then under the action of the oil pressure inside the box body, it flows through the main oil channel on the upper crankcase assembly 122 to the first branch K1 where the crankshaft assembly 104 is located, the second branch K2 where the balance shaft assembly 108 is located, and the third branch K3 where the cylinder head camshaft component 120 is located to lubricate and cool the components, and finally flows back to the oil pan assembly 131 through the engine body 134.

[0027] The second lubricating oil circuit Y2 of the oil cooling system can pump the stored oil in the oil pan assembly 131 to the oil cooler 112 through the auxiliary oil pump 1262 and the oil pump filter assembly 132, and then flow back to the main oil pump 1261 through the lower crankcase cover assembly 117, the lower crankcase assembly 123, the upper crankcase assembly 122, and the oil filter assembly 127, thereby realizing the recycling of the oil; in addition, the second lubricating oil circuit Y2 of the oil cooling system will be cooled and lowered by the circulating coolant discharged by the water pump assembly 109 when passing through the oil cooler 112, so that the oil can be maintained within the normal operating temperature range of the engine, thereby improving the reliability and life of the engine.

[0028] like Figure 4 The diagram is a schematic diagram of the first lubricating oil circuit Y1 of the oil cooling system. The specific operation is as follows: unscrew the oil filling plug 118 of the oil port, the oil flows into the chamber of the cylinder head camshaft component 120 and the cylinder block assembly 121 through the cylinder head cover 119, and flows into the lower crankcase assembly 123 through the oil passage holes of the upper crankcase assembly 122 and the lower crankcase assembly 123, and then flows to the main oil pump 1261 after preliminary filtration through the oil filter assembly 127, and the crankshaft assembly 104 drives the oil pump driven sprocket 125 and the oil pump assembly 126 through the oil pump chain assembly 124. During operation, the engine oil is pumped by the oil pump to the oil circulation pipe 128 arranged on the upper crankcase assembly 122, and then flows into the oil filter assembly 129 for secondary filtration, and then passes through the main oil channel hole on the upper crankcase assembly 122 to be divided into three channels: the crankshaft lubricating oil channel, the balance shaft lubricating oil channel and the camshaft lubricating oil channel, which lubricate and cool the crankshaft, the balance shaft and the camshaft respectively, and finally flows back to the oil pan assembly 131 through the engine body 134 for subsequent recycling.

[0029] like Figure 5As shown, it is a schematic diagram of the structure of the second lubricating oil circuit Y2 of the oil cooling system. As the engine continues to work, the oil will also heat up and flow back to the oil pan assembly 131. The crankshaft assembly 104 drives the oil pump driven sprocket 125 and the auxiliary oil pump 1262 to work through the oil pump chain assembly 124. The auxiliary oil pump 1262 pumps the high-temperature oil in the return oil pan assembly 131 to the lower crankcase cover assembly 117 and the oil cooler 112 through the oil pump oil filter assembly 132. The oil cooled by the coolant flows back to the upper crankcase assembly 122 and the lower crankcase assembly 123 through the return oil pipe 130, and then flows back to the main oil pump 1261 again after preliminary filtration by the oil filter assembly 127, thereby circulating to achieve stable lubrication and cooling effects of the engine.

[0030] The water cooling system of the dual-circulation cooling system is further explained below.

[0031] like Figure 1 and Figure 3 As shown, the vehicle is powered on and started, and the vehicle control system 200 controls the starter motor 101 to work, driving the starter reduction component 102 to rotate, and then driving the overrunning clutch assembly 103 to rotate counterclockwise, thereby driving the crankshaft assembly 104 to rotate synchronously counterclockwise, and the crankshaft position sensor 106 detects the change in the crankshaft position and sends a signal to the vehicle control system 200, controlling the engine assembly 100 to ignite and start according to the calibration procedure until it works normally, and then the crankshaft assembly 104 drives the balance shaft assembly 108 to rotate through gear meshing, and then drives The water pump impeller of the water pump assembly 109 rotates, pumping the coolant in the water tank radiator assembly 301 to the two branches of the water pump outlet pipe 110 and the oil cooler inlet pipe 111. One water flow passes through the engine body 134 to the thermostat 114, the engine internal circulation water pipe 115, and then flows back to the water pump assembly 109 through the water pump secondary water inlet 1092. The other water flow passes through the oil cooler 112 to the oil cooler outlet pipe 308, the three-way joint 306, the water pump inlet pipe 307, and then flows back to the water pump assembly 109 through the water pump main water inlet 1091.

[0032] like Figure 6 and Figure 7 As shown, as the water pump assembly 109 rotates, the water in the water pump inlet pipe 307 is pumped to the water pump outlet pipe 110, flows through the cylinder water inlet 107 and is divided into two paths to cool the cylinder piston of the engine body 134, then flows into the thermostat 114, flows into the engine internal circulation water pipe 115 through the thermostat bypass valve 1141, and then flows back to the water pump assembly 109 through the water pump secondary water inlet 1092, forming an internal circulation of water flow inside the engine. The direction of the internal circulation water flow is as shown in FIG. Figure 3 As indicated by the black arrow in .

[0033] Only when the temperature of the coolant inside the engine cylinder reaches the first temperature threshold value of 79°C set by the thermostat 114, the thermostat valve core 1143 of the thermostat 114 starts to work and move downward, compressing the thermostat compression spring 1144 to a certain stroke, and the thermostat main valve 1142 is gradually opened to a certain degree, while the opening of the thermostat bypass valve 1141 gradually decreases. At this time, part of the coolant flowing through the thermostat 114 still flows back to the water pump assembly 109 along the front thermostat bypass valve 1141 and the engine internal circulation water pipe 115 branch to form an internal circulation, and the other part of the coolant flows through the thermostat main valve 1142 to the thermostat cover 116 and the engine external circulation water pipe 311 to form an external circulation. The internal and external circulations coexist at the same time, and the water flow directions of the internal and external circulations are as follows: Figure 3 Indicated by the black and white arrows.

[0034] The thermostat 114 is provided with a thermostat bypass valve 1141, a thermostat main valve 1142, a thermostat valve core 1143 and a thermostat compression spring 1144. The rotation of the water pump assembly 109 pumps the coolant to the water pump outlet pipe 110, and then flows to the cylinder assembly 121 and the cylinder head camshaft component 120 through the cylinder water inlet 107. The thermostat 114 adjusts the opening of the thermostat main valve 1142 and the thermostat bypass valve 1141 according to the coolant temperature. When the coolant temperature is lower than the first temperature threshold value (79°C) set by the thermostat 114, the thermostat main valve 1142 is completely closed and the thermostat bypass valve 1141 is completely opened; when the coolant temperature exceeds the first temperature threshold value of 79°C of the thermostat 114 and is lower than the second temperature threshold value of 95°C, the thermostat main valve 1142 and the thermostat bypass valve 1141 are opened at the same time; when the coolant temperature exceeds the second temperature threshold value of 95°C of the thermostat 114, the thermostat main valve 1142 is completely opened and the thermostat bypass valve 1141 is completely closed.

[0035] The working mode of the water cooling system is further explained below.

[0036] like Figure 8As shown, the vehicle control system 200 monitors the temperature value of the water temperature sensor 113 and controls the working state of the fan motor assembly 302 as needed. When the engine is just started or has just started and the temperature is low, when the water temperature sensor 113 measures that the coolant temperature inside the engine body 134 is lower than the first temperature threshold (79°C) set by the thermostat 114, the thermostat 114 will not start working temporarily, that is, the thermostat valve core 1143 is at the upper limit position, and the thermostat main valve 1142 of the thermostat 114 is in a completely closed state under the action of the thermostat compression spring 1144. There is almost no coolant flowing between the water tank water inlet hose 309, the water tank water inlet hard pipe 310 and the engine external circulation water pipe 311 between the thermostat 114 and the water tank radiator assembly 301 (only a small amount of coolant overflows through the overflow port of the thermostat), and the thermostat bypass valve 1141 is fully opened at this time. Under the action of the water pump assembly 109, the coolant flows into the engine body 134 through the water pump outlet pipe 110, flows out from the cylinder head provided on the engine body 134 after internal circulation, flows to the engine internal circulation water pipe 115 through the thermostat bypass valve 1141, and then flows back to the water pump assembly 109. At the same time, the coolant flowing out of the other branch through the water pump assembly 109 flows into the interior of the oil cooler 112 through the oil cooler inlet pipe 111 and cools it, then flows into the water pump inlet pipe 307 through the oil cooler outlet pipe 308 and the tee 306, and then flows back to the water pump assembly 109. In this state, the thermostat main valve 1142 is never opened, and the coolant only circulates inside the water pump assembly 109, the cylinder block and cylinder head on the engine body 134, and the oil cooler 112, and does not pass through the water tank radiator assembly 301. This is called the internal circulation state. At this time, the coolant flow is small and the cooling effect is weak, which helps the engine reach normal operating temperature as soon as possible.

[0037] like Fig. 9 As shown, as the engine continues to work, the engine's heat dissipation demand will be higher, and the engine's internal circulation can no longer meet the engine's heat dissipation demand. When the operating temperature of the engine body 134 (i.e., the coolant temperature) exceeds the first temperature threshold of 79°C of the thermostat 114 and is less than the second temperature threshold of 95°C, the vehicle control system 200 controls the opening of the thermostat main valve 1142 according to the real-time temperature measured by the water temperature sensor 113, so that the thermostat main valve 1142 gradually opens, and at the same time, the opening of the thermostat bypass valve 1141 gradually decreases. At this time, the internal and external circulations of the engine coolant are carried out simultaneously.

[0038] like Fig.10As shown, when the engine runs at high speed for a long time, the engine temperature rises rapidly. When the temperature of the coolant exceeds the second temperature threshold of 95°C of the thermostat 114, the thermostat main valve 1142 will be fully opened, and the thermostat bypass valve 1141 will be fully closed. At this time, the coolant flows into the water tank radiator assembly 301 through the engine external circulation water pipe 311, while the engine internal circulation water pipe 115 branch between the thermostat 114 and the water pump assembly 109 has no coolant circulation. At this time, external circulation cooling is realized, and at the same time, the vehicle control system 200 turns on the fan temperature control switch 312 to drive the fan motor assembly 302 to work, and quickly cools the water tank radiator assembly 301, which helps to reduce the engine temperature to the normal operating temperature as soon as possible to prevent the engine from overheating and damage.

[0039] It should be noted that the thermostat 114 plays an important role in the internal and external circulation of the engine coolant, that is, it is in a closed state before the engine temperature reaches the normal operating temperature, and the coolant only realizes a small circulation inside the water pump assembly 109 and the cylinder body of the engine body 134, so that the engine assembly 100 can quickly heat up to a normal operating state; after the engine temperature exceeds the second temperature threshold of 95°C of the thermostat 114, the thermostat main valve 1142 will be fully opened, and the thermostat bypass valve 1141 will be fully closed to realize a large circulation. At the same time, the vehicle control system 200 drives the fan motor assembly 302 to work so that the system dissipates heat quickly, so that the engine can maintain a cooling state of internal and external circulation coexisting, ensuring the optimal normal operating temperature of the engine.

[0040] The parallel twin-cylinder engine dual-circulation cooling system activates different cooling circulation systems for different engine temperature states. When the temperature is low, the small circulation system is activated, the water flow is small, the cooling effect is weak, and the temperature rise time of the engine is shortened, which helps the engine reach the normal operating temperature as soon as possible and improves the combustion efficiency. When the temperature is too high, the large circulation system is activated, the water flow is large, and the fan motor is controlled by the temperature control switch to dissipate heat quickly, so that the engine temperature can quickly return to the normal operating temperature. When the temperature is within the normal operating temperature range of the engine, the internal and external circulations work at the same time to maintain the normal cooling and heat dissipation balance of the engine. At the same time, through the coupling design of the water cooling system and the oil cooling system, the engine oil temperature and coolant temperature can be maintained within the optimal operating temperature range, so that the engine can play the best stable performance.

[0041] Obviously, the embodiments described above are only part of the embodiments of the present application, rather than all the embodiments. The drawings provide preferred embodiments of the present application, but do not limit the patent scope of the present application.

Claims

1. A water cooling system, the water cooling system comprising an internal circulation system and an external circulation system, the internal circulation system acting on the inside of an engine assembly (100), the external circulation system acting on the outside of the engine assembly (100), the engine assembly (100) comprising an engine body (134), When the temperature of the coolant inside the engine body (134) is lower than a preset first temperature threshold, the internal circulation system is turned on and the external circulation system is turned off. When the temperature of the coolant inside the engine body (134) is higher than a preset first temperature threshold and lower than a preset second temperature threshold, the internal circulation system and the external circulation system are both turned on; When the temperature of the coolant inside the engine body (134) is higher than a preset second temperature threshold, the external circulation system is turned on and the internal circulation system is turned off. in, The first temperature threshold and the second temperature threshold are set by a thermostat (114) in the engine body (134).

2. The cooling system according to claim 1, characterized in that: The thermostat (114) comprises a thermostat bypass valve (1141), a thermostat main valve (1142), a thermostat valve core (1143) and a thermostat compression spring (1144); the thermostat main valve (1142) controls the on-off of the external circulation system, and the thermostat bypass valve (1141) controls the on-off of the internal circulation system.

3. The cooling system according to claim 1, characterized in that: The first temperature threshold is 79°C, and the second temperature threshold is 95°C.

4. The cooling system according to claim 1, characterized in that: A water temperature sensor (113) is provided in the engine assembly (100), and the water temperature sensor (113) monitors the temperature of the coolant inside the engine body (134).

5. The cooling system according to claim 1, characterized in that: When the internal circulation system is turned on, the coolant flows into the engine body (134) through the water pump outlet pipe (110) under the action of the water pump assembly (109). After heat exchange, the coolant flows out from the cylinder head arranged on the engine body (134). The coolant flows to the engine internal circulation water pipe (115) through the thermostat bypass valve (1141), and then flows back to the water pump assembly (109). At the same time, another branch of coolant flowing out of the water pump assembly (109) flows into the interior of the oil cooler (112) through the oil cooler inlet pipe (111) and is cooled. The coolant flows into the water pump inlet pipe (307) through the oil cooler outlet pipe (308) and the tee (306), and then flows back to the water pump assembly (109); When the external circulation system is turned on, the coolant flows into the water tank radiator assembly (301) through the engine external circulation water pipe (311), and the fan motor assembly (302) works to cool the water tank radiator assembly (301) to quickly reduce the temperature.

6. A dual-circulation cooling system for a parallel twin-cylinder engine, characterized in that: The dual-circulation cooling system of the parallel twin-cylinder engine comprises an oil cooling system and a water cooling system as claimed in any one of claims 1 to 5.

7. The parallel twin-cylinder engine dual-circulation cooling system according to claim 6, characterized in that: The oil cooling system comprises a first lubricating oil circuit (Y1) and a second lubricating oil circuit (Y2). The first lubricating oil circuit (Y1) comprises a main oil pump (1261), wherein the main oil pump (1261) pumps the engine oil to the engine oil internal circulation pipe (128) on the upper crankcase assembly (122), and enters the first branch (K1) where the crankshaft assembly (104) is located, the second branch (K2) where the balance shaft assembly (108) is located, and the third branch (K3) where the cylinder head camshaft component (120) is located through the main oil channel hole on the upper crankcase assembly (122), and then flows back to the oil pan assembly (131) after passing through the engine body (134). The second lubricating oil circuit (Y2) comprises an auxiliary oil pump (1262) and an oil pump filter assembly (132). The auxiliary oil pump (1262) pumps the engine oil in the oil pan assembly (131) into the engine oil cooler (112). The engine oil flows back to the main oil pump (1261) after passing through the lower crankcase cover assembly (117), the lower crankcase assembly (123), the upper crankcase assembly (122), and the oil filter assembly (127).

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