JP2006183488A - Cooling water feeding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling water feeding device utilizing a dead space between a radiator and an engine while securing a space around a cylinder head. <P>SOLUTION: The cooling water feeding device 120 is provided with a crank case 54 for supporting a crank shaft 58 rotated and driven by an engine 50; a cooling water pump 125 driven by driving force from the crank shaft 58 and pressurizing and delivering the cooling water; the radiator 129 arranged on a side part of the crank case 54 and radiating the heat of the cooling water; and a thermostat 130 arranged in a passage between the radiator 129 and the cooling water pump 125, making the cooling water flow to the radiator 129 when a temperature of the cooling water is higher than a predetermined value, and bypassing the radiator 129 when the temperature is equal to or lower than the predetermined value; and the cooling water for cooling the engine 50 is supplied to a water jacket 122 formed in the engine 50. The cooling water pump 125 is arranged on the side surface of the crank case 54, and the thermostat 130 is arranged in the space between the cooling water pump 125 and the radiator 129. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cooling water supply device that supplies cooling water to a water jacket formed in a cylinder head and cools the cylinder head.

  When generating power efficiently by the engine, it may be preferable to set the temperatures of the cylinder head and the cylinder block, respectively. In this case, it is known that a radiator is disposed on the side surface of the crankcase, and a thermostat is disposed on the side of the cylinder head (see, for example, Patent Document 1).

JP 2003-172143 A

  However, according to such a configuration, since the distance from the cylinder head to the radiator is increased, the cooling water flow path (cooling water pipe) becomes long. In addition, the radiator only covers the AC generator (ACG) in a side view, and does not have a structure that covers other components. For this reason, there is a problem that a dead space is generated between the radiator and the engine. Furthermore, since the thermostat is arranged in the cylinder head, there is a problem that the size of the cylinder around which many parts are arranged is further increased.

  The present invention has been made in view of such a problem, and an object thereof is to provide a cooling water supply device that effectively uses a dead space between a radiator and an engine while securing a space around a cylinder head. To do.

  In order to solve the above problems, a cooling water supply device according to a first aspect of the present invention supplies cooling water for cooling the engine to a water jacket formed in the engine, and is driven to rotate by the engine. A crankcase that supports the crankshaft, a cooling water pump that is driven by a driving force from the crankshaft to pressurize and discharge the cooling water, a radiator that is disposed on the side of the crankcase and radiates the cooling water, A thermostat that is disposed in a path between the radiator and the cooling water pump, and causes the cooling water to flow through the radiator when the temperature of the cooling water is higher than a predetermined value, and bypasses the radiator when the temperature is lower than the predetermined value. A cooling water pump is disposed on a side surface of the case, and a thermostat is disposed in a space between the cooling water pump and the radiator.

  The cooling water supply apparatus according to the first aspect of the present invention has a radiator fan for cooling the radiator at the end of the crankshaft, and the thermostat is disposed in front of and below the radiator fan in a side view. It is preferable.

  A cooling water supply device according to the second aspect of the present invention supplies cooling water to a water jacket formed in the engine, and is disposed on a side portion of the engine to dissipate cooling water. A radiator cover for covering the radiator, a cooling water pump for pressurizing and discharging the cooling water, and a radiator and the cooling water pump. When the temperature of the cooling water is higher than a predetermined value, the cooling water is supplied to the radiator. A cooling water pipe joint that has a thermostat that bypasses the radiator when less than a predetermined value and a thermostat cover that covers the thermostat, and a bypass passage through which the cooling water bypassing the radiator flows is connected to the thermostat cover The cooling water pipe joint overlaps at least a part of the radiator cover in a side view.

  At this time, in a side view, at least a part of the radiator and the thermostat cover are arranged so as to overlap with each other, and a discharge hole for discharging the cooling water is formed at a position where the radiator and the thermostat cover overlap with each other. It is preferable to have a connecting pipe that connects the two.

  In the cooling water supply devices according to the first and second aspects of the present invention, the thermostat is a valve body provided in the interior, and the interior is partitioned into a first thermostat chamber and a second thermostat chamber so as to be freely opened and closed. And a first introduction part and a second introduction part connected to each of the first and second thermostat chambers, and the first and second introduction parts are connected to the upper ends of the first and second thermostat chambers in the vertical direction. It is preferable to be located at the same height or higher.

  When the cooling water supply device according to the first aspect of the present invention is configured as described above, since the thermostat is disposed between the radiator and the cooling water pump disposed in the crankcase, the radiator and the crankcase The dead space between them can be used effectively. Further, since the thermostat becomes a part of the cooling water flow path for flowing the cooling water to the cooling pump, the cooling water pipe through which the cooling water flows can be shortened. At this time, the dead space can be effectively used by disposing the thermostat in front of and below the radiator fan.

  Moreover, if the cooling water supply device according to the second aspect of the present invention is configured as described above, the cooling water pipe joint formed to protrude from the thermostat cover can be protected by the radiator cover. At this time, the distance between the radiator and the thermostat can be shortened by forming the discharge hole at a position overlapping with the thermostat cover of the radiator, and the connecting pipe can be protected by the radiator cover.

  At this time, the interior of the thermostat is partitioned by the valve body so as to be freely opened and closed, and the first and second introduction parts are configured to communicate with the first and second thermostat chambers partitioned by the valve body. 2 By configuring the introduction part so that it is positioned at the same height or higher as the upper ends of the first and second thermostat chambers in the vertical direction, there is no need to provide a special structure for removing the air staying inside. It is possible to make it difficult for air to stay in the first and second thermostat chambers.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. First, a scooter type vehicle 1 on which a cooling water supply device according to the present invention is mounted will be described with reference to FIG. The scooter-type vehicle 1 has a body frame 2, which is positioned at the front portion thereof, and has a head pipe 3 extending in the vertical direction, a down frame 4 extending downward from the head pipe 3, and a down frame. The frame 4 includes a pair of left and right side frames 5 extending downward and rearward and further rearward and obliquely upward from a substantially central portion of the frame 4, and an arcuate curved frame 7 attached to the side frames 5 via side plates 6. .

  A steering shaft (not shown) is rotatably attached to the head pipe 3, and a front fork 8 is attached to the lower end of the steering shaft. A front wheel 9 is supported at the lower end of the front fork 8. On the other hand, a handle post 10 is attached to the upper end of the steering shaft. Further, a handle 11 is attached to the upper end of the handle post 10, and the front wheel 9 can be steered by operating the handle 11. An upper stay 12 and a lower stay 13 are attached to extend forward from the head pipe 3, and a front car 14 is attached to the front ends of these upper and lower stays 12, 13.

  A fuel tank 15 is attached between the pair of side frames 5 below the pair of side frames 5. A link attachment portion 48 formed at the front end of the power unit 16 is attached to the rear end of the curved frame 7 located behind the fuel tank 15 so as to be swingable up and down, and at the rear end of one of the side frames 5 The rear end of the power unit 16 is attached via the cushion unit 17. Here, the fuel tank 15 is provided with a fuel pump 18 having an overturn sensor inside, and is configured to be able to supply fuel from a fuel filler port (cap) 19 provided at the top. The power unit 16 includes an engine 50, a transmission 90, a throttle body 21, an air cleaner 22, an exhaust pipe 23 extending rearward from the engine 50, and a muffler 24 connected to the rear end of the exhaust pipe 23. Is done. A rear wheel 25 is attached to the rear end of the power unit 16, and the rear wheel 25 is driven by the power unit 16 so that the scooter type vehicle 1 can travel with power.

  A luggage box 26 and a grab rail 20 are attached to the rear portion of the side frame 5. The luggage box 26 is supported at the front by a front cross pipe 27 attached to the side frame 5 via the front plate 28, and supported at the rear by a portal frame 29 attached to the side frame 5. The grab rail 20 is supported by a rear stay 30 extending upward from the side frame 5. The helmets 31 and 32 represent a state of being stored in the luggage box 26. A rear storage box 33 is attached to the rear part of the grab rail 20.

  In the scooter type vehicle 1 configured as described above, the front upper portion of the vehicle body is covered with the front cover 34, and the left and right front side covers 35 are attached to the lower side of the front cover 34. A turn signal lamp (not shown) is attached to the front side cover 35. A front inner cover 36 is attached to the rear portion of the front cover 34, and a side portion of the step floor 37 on which the driver and the passenger rest his / her feet is covered with a side cover and an under cover 38. Further, a seat 39 is attached to the upper portion of the luggage box 26, and the lower periphery of the seat 39 is covered with the body cover and the body side cover 40. Further, a handle cover 42 that covers the handle 11 is attached to the upper portion of the front cover 34, and a head lamp 43 is attached to the handle cover 42. A front fender 44 is attached so as to cover the upper part of the front wheel 9, and a rear fender 45 is attached so as to cover the upper part of the rear wheel 25.

  A tail lamp 46 is disposed below the grab rail 20, and a battery 41 is stored between the front cover 34 and the front inner cover 36.

  Next, details of the power unit 16 will be described with reference to FIGS. In the present embodiment, the direction of the arrow F in FIG. 2 is the front, and the direction of the arrow U in FIG. The engine 50 configuring the power unit 16 includes a cylinder head cover 51, a cylinder head 52, a cylinder block 53, and a crankcase 54. In a cylinder chamber 55a formed by being surrounded by a cylinder sleeve 55 fitted in the cylinder block 53, a piston 56 is disposed so as to be slidable in the vertical direction. The piston 56 is connected to a crankcase via a connecting rod 57. It is connected to a crankshaft 58 that is rotatably held in 54. An intake port 60 and an exhaust port 61 communicate with the combustion chamber 59 formed by the cylinder block 53 (cylinder sleeve 55), the cylinder head 52, and the piston 56 via an intake port and an exhaust port, respectively. The saddle-shaped intake valve 62 and the saddle-shaped exhaust valve 63 are each provided with an intake port by valve springs 64 and 65, one end of which is attached to the valve shaft and supported by the retainer, and the other end is supported by the cylinder head 52. And the exhaust port is normally biased in the direction of closing.

  Further, a camshaft 66 for opening and closing the intake valve 62 and the exhaust valve 63 is rotatably disposed in the cylinder head 52. The camshaft 66 is arranged on a cam driven sprocket 67 and a crankshaft 58. A timing chain 69 is wound around the cam drive sprocket 68 provided. Therefore, the camshaft 66 rotates in accordance with the rotation of the crankshaft 58, and the cams 70 and 71 formed on the camshaft 66 push down the intake valve 62 and the exhaust valve 63 via the rocker arms 72 and 73. Open and close intake and exhaust ports. The intake port 60 is provided with an injector 74, and fuel is atomized into the intake port 60 and injected by the injector 74. Further, a spark plug 75 is attached to the cylinder head 52.

  A cam chain tensioner 84 for adjusting the timing of opening and closing the intake valve 62 and the exhaust valve 63 by the cams 70 and 71 by adjusting the tension of the timing chain 69 is attached to the side of the cylinder block 53. .

  In the engine 50 configured as described above, a mixture of the air cleaned by the air cleaner 22 and the fuel injected by the injector 74 is supplied from the intake port 60 to the combustion chamber 59 and compressed by the piston 56 and then ignited. It is ignited by the plug 75 and combusted to become energy for rotating the crankshaft 58 through the piston 56, and then exhausted as exhaust gas from the exhaust port 61 to the outside.

  The crankshaft 58 includes a right crankshaft half body 58a and a left crankshaft half body 58b, and a connecting rod 57 is connected to the crankshaft 57 via a crank pin 76 that is connected to both the crankshaft half bodies 58a and 58b. It is connected. The crankcase 54 that houses the crankshaft 58 includes a right case half 54a and a left case half 54b, and one end of the crankshaft 58 (the journal portion of the right crankshaft half 58a) is provided with a bearing 77. The other end (the journal portion of the left crankshaft half 58b) is supported by the left case half 54b via a bearing 78. Further, an ACG 79 and a radiator fan 85 are disposed at the tip of the journal portion of the right crankshaft half 58a.

  A left side portion of the left case half 54b extends rearward to form a part of the transmission case 80, and a transmission chamber 82 surrounded by a transmission cover 81 attached to the left side surface of the left case half 54b. A transmission 90 is stored. The transmission 90 is attached to the front end of the journal portion of the left crankshaft half 58b extending into the transmission chamber 82 and rotates integrally with the drive pulley 91. The transmission 90 is positioned behind the transmission chamber 80 and the crankshaft 58. A countershaft 92 that extends in parallel and is rotatably mounted, a driven pulley 93 that is mounted so as to be relatively rotatable with respect to the countershaft 92 at a substantially central portion of the countershaft 92, and is mounted and driven at the left end of the countershaft 92. A clutch 94 that engages and disengages the pulley 93 and the counter shaft 92 and a transmission belt (not shown) that is wound around the drive pulley 91 and the driven pulley 93 and transmits the rotation of the drive pulley 91 to the driven pulley 93.

  The drive pulley 91 is fixedly attached to the crankshaft 58 so as to be integrally rotatable. The drive pulley 91 is relatively movable in the axial direction with respect to the fixed pulley half 91a and rotates integrally with the crankshaft 58. The transmission belt is sandwiched between the fixed pulley half 91a and the movable pulley half 91b. On the other hand, the driven pulley 93 is fixed to the countershaft 92 so as to be rotatable relative to the countershaft 92. The driven pulley 93 can move relative to the stationary pulley half 93a in the axial direction and can rotate relative to the countershaft 92. The movable pulley half 93b, and the transmission belt is sandwiched between the fixed pulley half 93a and the movable pulley half 93b. Therefore, by variably setting the pulley widths of the drive pulley 91 and the driven pulley 93, the wrapping radius of the transmission belt around the pulleys 91 and 93 is continuously changed, so that the gear ratio is continuously variable (continuously). Can be controlled.

  In parallel with the counter shaft 92, a rear wheel shaft 96 to which the idle shaft 95 and the rear wheel 25 are attached is rotatably attached, and a gear train attached to the counter shaft 92, the idle shaft 95 and the rear wheel shaft 96 is arranged. The rotational driving force of the countershaft 92 is transmitted to the rear wheel 25 via this. As described above, the output of the engine 50 is transmitted to the crankshaft 58, and after being shifted by the transmission 90, is transmitted to the rear wheel 25.

  In addition, when such a power unit 16 is operated, since it generates heat | fever, it is necessary to cool each part. Therefore, a water jacket 122 that cools the cylinder head 52 by flowing cooling water therein is formed and cooled by the cooling water. The cylinder block 53 protrudes outward at the side. A plurality of cooling fins 86 are formed to release heat generated in the cylinder block 53 from the cooling fins 86, and the transmission case 80 extends forward at the front portion of the transmission case 80. A cooling air introduction passage 83 for taking outside air into the transmission chamber 82 is provided for cooling.

  Then, the cooling water supply apparatus 120 used for the scooter type vehicle 1 configured as described above will be described with reference to FIGS. The cooling water supply device 120 supplies cooling water into a water jacket 122 formed on the cylinder head 52 to cool the cylinder head 52. The cooling water pump 125 pressurizes and discharges the cooling water. From the radiator 129 that collects and dissipates the cooling water used for cooling by the water jacket 122, and the thermostat 130 that returns to the water jacket 122 without releasing heat by the radiator 129 when the temperature of the cooling water is below a predetermined value. Composed.

  The cooling water pump 125 is attached to one end of a pump shaft 132 that extends substantially parallel to the right crankshaft half 58a, and has an impeller 131 that pressurizes cooling water by being rotated by the pump shaft 132. A pump driven sprocket 133 is attached to the other end of the pump shaft 132. In addition, a pump idle shaft 134 is provided between the pump shaft 132 and the right crankshaft half 58a and extends substantially parallel to the shafts 58a and 132. A pump driven gear 136 that meshes with a pump drive gear 135 coupled to the right crankshaft half 58a is attached to the pump idle shaft 134, and a pump drive sprocket 137 is attached to the pump idler shaft 134 along with the pump drive gear 135. A pump chain 138 is wound around the pump drive sprocket 137 and the pump driven sprocket 133. Thereby, the rotation of the right crankshaft half 58a due to the driving of the engine 50 is transmitted to the pump idle shaft 134 via the pump drive gear 135 and the pump driven gear 136, and the rotation is transmitted from the pump drive sprocket 137 to the pump chain. The pump shaft 132 rotates by being transmitted to the pump driven sprocket 133 via 138, and the cooling water is pressurized and discharged from the discharge port 126 of the cooling water pump 125.

  A water jacket 122 that is a space formed so as to cover the combustion chamber 59 is provided in front of the combustion chamber 59 formed in the cylinder head 52. Further, the cylinder head 52 has a cooling water lead-out part 121 formed in the upper rear part of the water jacket 122 in which a cooling water lead-out passage 121a that communicates with the outside and the water jacket 122 and discharges the cooling water to the outside is formed. Yes. Further, the cylinder head 52 has a cooling water introduction space 123 formed adjacent to the lower rear of the water jacket 122, and the cooling water introduction space 123 is opened on the rear side surface below the cylinder head 52. And communicates with the water jacket 122.

  On the other hand, a cooling water introduction portion 128 that protrudes downward is formed on the lower side surface of the front portion of the cylinder block 53. The cooling water introduction portion 128 has an introduction port 128a that is open to the side. A first passage 140a extending in the direction and a second passage 140b communicating with the first passage 140a and extending forward (hereinafter referred to as “cooling water introduction” together with the first and second passages 140a and 140b). Called passage 140 "). The second passage 140b has a lead-out port 128b opened at the front end surface of the cylinder block 53. When the cylinder head 52 is attached to the cylinder block 53, the second passage 140b has an opening (lead-out port 128b). ) Communicates with the opening of the cooling water introduction space 123 of the cylinder head 52, and the cooling water introduction passage 140 communicates with the water jacket 122. Further, the discharge port 126 of the cooling water pump 125 and the cooling water introduction part 128 formed in the cylinder block 53 are disposed close to each other, and these are connected by a cooling water supply pipe 127.

The thermostat 130 has a first introduction part 141 and a second introduction part 142, and when the temperature of the cooling water flowing from the first and second introduction parts 141 and 142 is below a predetermined temperature, The second introduction unit 142 is closed and the cooling water is discharged from the first introduction unit 141 to the outlet unit 143. When the temperature is higher than a predetermined temperature, the first introduction unit 141 is closed and the second introduction unit 142 is closed. The cooling water is discharged to the derivation unit 143. Further, the thermostat 130 is provided with a valve body 154 whose axis is inclined forward in a side view, and the thermostat 130 has a first thermostat chamber S ₁ communicated with the first introduction part 141 by the valve body 154. And a second thermostat chamber S ₂ communicating with the second introduction part 142.

  A first cooling water pipe 144 is connected to the cooling water outlet portion 121 formed in the cylinder head 52, and the first cooling water pipe 144 is connected to the second cooling water pipe 146 a and the third cooling water at the branch portion 145. Branches to the water pipe 146b. The second cooling water pipe 146 a is connected to the suction hole 147 of the radiator 129, and the third cooling water pipe 146 b is connected to the first introduction part 141 of the thermostat 130. On the other hand, the second introduction portion 142 of the thermostat 130 is connected to a discharge hole 148 of a radiator 129 disposed in the vicinity via a rigid connection pipe 149. The branch portion 145 is formed with a positioning portion 145a for positioning when the first to third cooling water pipes 144, 146a, 146b are attached.

  The housing (thermostat cover 130a) for storing the thermostat 130 is integrally formed with the housing for storing the cooling water pump 125, and the lead-out portion 143 of the thermostat 130 and the inlet 150 of the cooling water pump 125 are directly connected. Has been. Therefore, the thermostat 130 constitutes a part of the cooling water flow path that sends the cooling water to the suction port 150 of the cooling water pump 125, and the flow path through which the cooling water flows can be shortened, and the overall size can be reduced. Moreover, the assembly property of the power unit 16 can be improved by connecting the radiator 129 and the thermostat 130 with the connecting pipe 149.

  According to the cooling water supply device 120 configured as described above, the cooling water discharged from the cooling water pump 125 passes through the cooling water introduction passage 140 of the cooling water introduction portion 128 formed in the cylinder block 53 and is water. It flows into the jacket 122. Then, the cylinder head 52 is cooled and discharged from the cooling water outlet 121 to the outside. The discharged cooling water flows into the suction hole 147 of the radiator 129 or the first introduction part 141 of the thermostat 130. When the temperature of the cooling water is equal to or lower than a predetermined value, the thermostat 130 causes the second introduction part 142 to flow. Therefore, when the temperature of the cooling water is higher than a predetermined value, the first introduction part 141 is closed by the thermostat 130 and the heat is radiated through the radiator 129. After that, the second introduction unit 142 returns to the cooling water pump 125 to circulate.

  As described above, the cooling water intake (cooling water introduction portion 128) for cooling the cylinder head 52 is not formed in the cylinder head 52 but in the cylinder block 53. While improving the design freedom around, the dead space around the cylinder block 53 can be used effectively. As is apparent from FIG. 4 and the like, the cooling water introduction portion 128 is provided in the front end portion of the cylinder block 53, that is, in the vicinity of the cylinder head 52, so that the cooling water introduction passage 140 is shortened as a whole. Therefore, the weight can be reduced and the manufacturing cost can be reduced. Further, the processing of the cooling water introduction passage 140 in the cylinder block 53 is facilitated.

  Such a cooling water supply device 120 is concentrated on the right side of the power unit 16, and the radiator 129 has a radiator cover 152 and a radiator outer cover 153 attached to the right end of the right crankcase half 54a. Stored in At this time, the radiator 129 is disposed on the outer side of the vehicle body with respect to the radiator fan 85, the thermostat 130 is disposed in front of and below the radiator 129 in a side view, and the cooling water pump 125 and the thermostat 130 are connected to the radiator. A part of 129 (radiator cover 152) is disposed so as to overlap in a side view.

Therefore, since the cooling water pump 125 can be disposed at a position close to the crankshaft 58 on the side of the crankcase 54, the driving force of the crankshaft 58 can be easily used. Further, since the cooling water pump 125 and the thermostat 130 can be disposed in the space formed between the radiator 129 (the radiator cover 152) and the cylinder block 53 or the crankcase 54, the dead space can be effectively utilized, Can be made compact. Similarly, by arranging the thermostat 130 (thermostat cover 130a) between the cylinder block 53 and the link mounting portion 48, space efficiency can be improved. Furthermore, by disposing the thermostat 130 below the radiator 129, it is possible to make it difficult for air (bubbles) to stay in the thermostat 130. Furthermore, since the second thermostat chamber S ₂ than the line L ₁ which extends horizontally from an upper end in communication with the first inlet portion 142 below the outlet 148 is disposed, the second thermostat chamber S ₂ in air ( Bubbles) can be made difficult to stay. In addition, by tilting the axis L ₂ of the thermostat 130 with respect to the vertical direction, the height of the thermostat 130 can be shortened, and the position where the air stays in the thermostat 130 can be arbitrarily determined, and the air is placed at that position. It is possible to vent the air efficiently by providing a passage for removing the air.

  Further, the cooling water supply device 120 is concentrated on the right side of the power unit 16 so that the cooling water pipes (first to third cooling water pipes 144, 146a, 146b) are also concentrated on the right side. . Furthermore, as shown in FIG. 11, the cooling water pipe 121 and the cooling water outlet portion 121 through which the cooling water flows in and out, the suction hole 147, the discharge hole 148, and the cooling water introduction portion 128 have a ladder shape in a side view. Therefore, the cooling water pipe can be easily assembled and maintained. Moreover, by setting it as such a structure, the length of the bypass flow path (3rd cooling water pipe 146b) for circulating cooling water without passing through the radiator 129 can be shortened.

  At this time, the third cooling water pipe 146b branched at the branching portion 145 is connected to a cooling water pipe joint 141a (first introduction portion 141) formed in the thermostat cover 130a extending substantially vertically downward. At least a part of the cooling water pipe joint 141a protruding outward from the cooling water pipe 146b and the thermostat cover 130a is covered and protected by the radiator cover 152 in a side view. Similarly, since the discharge hole 148 of the radiator 129 and the second introduction part 142 of the thermostat 130 are formed so as to overlap in a side view, the connecting pipe 149 that connects them can be protected by the radiator cover 152.

  By the way, in the engine 50 shown in the present embodiment, in addition to the cooling water supply device 120 described above, the O2 sensor 116 for detecting the oxygen concentration of the exhaust gas in the exhaust port 61 and the temperature of the cooling water in the water jacket 122 are used. A water temperature sensor 119 for measuring the temperature is attached to the cylinder head 52. The O2 sensor attachment hole 116a and the water temperature sensor attachment hole 119a for attaching these sensors 116 and 119 are provided on the right side of the power unit 16 in the same manner as the cooling water outlet portion 121. It is formed in the part. Further, since the axes of these mounting holes 116a and 119a are disposed substantially parallel to the axis of the cooling water outlet passage 121a, as shown in FIG. 5, the cooling water outlet 121, the O2 sensor 116, and the water temperature The sensor 119 extends substantially in parallel. Therefore, when attaching these sensors 116 and 119 or attaching the first cooling water pipe 144 or the like to the cooling water outlet portion 121, the operation can be performed from one side (right side) of the engine 50, so that the attaching operation becomes easy.

1 is a side view of a scooter type vehicle to which a cooling water supply device according to the present invention is attached. It is a top view of a power unit. It is a left view of a power unit. It is a right view of a power unit. It is sectional drawing of a cylinder head. It is a sectional side view of the principal part containing a cooling water supply apparatus. It is a plane sectional view of the important section containing a cooling water supply device. It is sectional drawing of the principal part of the power unit containing a cooling water supply apparatus. It is sectional drawing of the principal part of a cylinder block. It is a front view of a power unit. It is explanatory drawing which shows the structure of a cooling water flow path.

Explanation of symbols

50 Engine 54 Crankcase 58 Crankshaft 85 Radiator fan 120 Cooling water supply device 122 Water jacket 125 Cooling water pump 129 Radiator 130 Thermostat 130a Thermostat cover 141a Cooling water pipe joint 148 Discharge hole 149 Connection pipe 152 Radiator cover 154 Valve body S _1st 1 thermostat room S ₂ 2nd thermostat room

Claims (5)

A cooling water supply device for supplying cooling water for cooling the engine to a water jacket formed in the engine,
A crankcase that supports a crankshaft that is rotationally driven by the engine;
A cooling water pump driven by a driving force from the crankshaft and pressurizing and discharging the cooling water;
A radiator disposed on a side portion of the crankcase to dissipate the cooling water;
It is arranged in a path between the radiator and the cooling water pump, and when the temperature of the cooling water is higher than a predetermined value, the cooling water is allowed to flow through the radiator, and when the temperature is lower than a predetermined value, the radiator is bypassed. A thermostat,
The cooling water pump is disposed on a side surface of the crankcase,
A cooling water supply apparatus, wherein the thermostat is disposed in a space between the cooling water pump and the radiator. A radiator fan for cooling the radiator at an end of the crankshaft;
The cooling water supply device according to claim 1, wherein the thermostat is disposed in front of and below the radiator fan in a side view. A cooling water supply device for supplying cooling water for cooling the engine to a water jacket formed in the engine,
A radiator disposed on a side of the engine for radiating the cooling water;
A radiator cover covering the radiator;
A cooling water pump for pressurizing and discharging the cooling water;
It is arranged in a path between the radiator and the cooling water pump, and when the temperature of the cooling water is higher than a predetermined value, the cooling water is allowed to flow through the radiator, and when the temperature is lower than a predetermined value, the radiator is bypassed. A thermostat that lets you
A thermostat cover covering the thermostat;
A cooling water pipe joint to which a bypass passage through which cooling water bypassing the radiator flows is connected to the thermostat cover, is formed,
In the side view, the cooling water supply device is characterized in that the cooling water pipe joint overlaps at least a part of the radiator cover. In the side view, the radiator and the thermostat cover are arranged so that at least a part thereof overlaps, and a discharge hole for discharging the cooling water is formed at a position overlapping the thermostat cover of the radiator,
The cooling water supply device according to claim 3, further comprising a connection pipe that connects the discharge hole and the inside of the thermostat cover. The thermostat is a valve body provided inside, and the inside is divided into a first thermostat chamber and a second thermostat chamber so as to be freely opened and closed, and is connected to each of the first and second thermostat chambers. Having an introduction part and a second introduction part,
The cooling water supply according to any one of claims 1 to 4, wherein the first and second introduction parts are positioned at the same height as or higher than the upper ends of the first and second thermostat chambers in the vertical direction. apparatus.

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