JP2012184672A - Internal combustion engine cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal combustion engine cooling device including a thermostat regulating the flow of cooling water in a cylinder block during warm-up, the device capable of precisely leading the cooling water in the cylinder block to a temperature sensing part of the thermostat during the warm-up.SOLUTION: A thermostat 100 is arranged so that an axial line of a valve element 102 (axial center of a temperature sensing part 104) goes along a horizontal direction, and a through-hole 102a communicating the upstream side and the downstream side of the valve element 102 is provided at a vertical direction lower side of the valve element 102. In accordance with such a structure, the cooling water (hot water) in the cylinder block (in-block cooling water passage 31) is precisely led to the temperature sensing part 104 of the thermostat 100 during the warm-up, and the cooling water in the cylinder block is reliably sensed by the temperature sensing part 104 of the thermostat.

Description

  The present invention relates to a cooling device for an internal combustion engine mounted on a vehicle or the like.

  In an internal combustion engine (hereinafter also referred to as an engine) mounted on a vehicle or the like, a water jacket is provided in the internal combustion engine (cylinder head and cylinder block) as a cooling water passage, and the cooling water is circulated through the water jacket by a water pump. Thus, the entire internal combustion engine is cooled (warmed up).

  Further, as a cooling device for an internal combustion engine, for a water jacket of a cylinder head (hereinafter also referred to as “head side water jacket”) and a water jacket of a cylinder block (hereinafter also referred to as “block side water jacket”). A cooling device for an internal combustion engine (generally referred to as “two-system cooling device”) in which cooling water is circulated in parallel has been proposed (see, for example, Patent Documents 1 and 2).

  In such a two-system cooling device, for example, a thermostat that restricts or allows the flow of the cooling water in the block-side water jacket is provided, and the cooling water is supplied to the block-side water jacket when the internal combustion engine is cold-started. The cooling water is supplied to the head-side water jacket while being stopped (water in the block is stopped). According to such a cooling device, the temperature of the cylinder block can be quickly increased while suppressing an excessive increase in the temperature of the cylinder head, so that friction loss at various locations in the internal combustion engine (cylinder friction loss, etc.) The fuel consumption (fuel consumption rate) can be improved.

  However, in such a two-system cooling device, when the internal combustion engine is warmed up, the cooling water does not flow through the block-side water jacket (only the flow of convection), so the temperature of the cooling water in the cylinder block during the warming up The temperature is not sensitive. In consideration of such a point, there is a technique described in Patent Document 3 below. In the cooling system described in Patent Document 3, a through hole (leakage passage) is provided in the valve seat of the thermostat, and a small amount of cooling water in the cylinder block (in the first cooling passage) penetrates during cold start. It passes through the hole and flows into the temperature sensitive cylinder.

JP 2008-133772 A JP 2009-097352 A JP 2004-346828 A

  By the way, the above-mentioned patent document 3 only describes that a through hole is provided in the valve seat, and does not disclose where to place the through hole. Therefore, in the cooling system described in Patent Document 3, there is room for improvement in that the cooling water in the cylinder block is appropriately guided to the temperature sensing part of the thermostat during warm-up.

  The present invention has been made in view of such circumstances, and in an internal combustion engine cooling apparatus having a thermostat that restricts the flow of cooling water in the cylinder block during warm-up, the cooling water in the cylinder block during warm-up is provided. An object of the present invention is to provide a structure capable of accurately guiding the temperature to the temperature sensing part of the thermostat.

  The present invention relates to a cooling device for cooling an internal combustion engine by circulating cooling water, the cooling water passage in the head (head side water jacket) formed in the cylinder head of the internal combustion engine, and the cylinder block of the internal combustion engine And a thermostat (block thermostat) for restricting the flow of the cooling water in the block cooling water passage when the temperature of the cooling water is lower than a predetermined water temperature. In such a cooling device, the thermostat is configured to open the valve body in a valve-opening direction when the temperature of the valve body and the cooling water exceeds a predetermined temperature. When the thermostat is arranged so that the axis (opening / closing direction) of the valve body is along the horizontal direction Moni, the vertically lower side of the valve body, and technically characterized in that a through-hole that communicates the upstream side and the downstream side of the valve body is provided.

  According to the present invention, since the through hole that communicates the upstream side and the downstream side of the valve body of the thermostat is provided, a small amount of cooling water flows into the cylinder block during warm-up (when the thermostat is closed). As a result, cooling water flows into the thermostat. In addition, the thermostat is arranged so that the axis of the valve body (axial center of the temperature sensing part) is along the horizontal direction, and the through hole is provided on the lower side in the vertical direction of the valve body. The cooling water in the cooling water passage) can be accurately guided to the temperature sensing part of the thermostat. That is, if the through hole is provided on the lower side in the vertical direction of the valve body, the hot water of the cooling water flowing in the thermostat flows upward (to the temperature sensing part side) and heats the thermo wax in the temperature sensing part. On the other hand, the cold water is pushed downward by the hot water and flows out from the through hole to the downstream side (see FIG. 8). As a result, the maximum temperature of the cooling water in the cylinder block can be sensed with high sensitivity by the temperature sensing part of the thermostat, so that the warm-up performance is improved.

  Here, the through hole may be provided in the valve body, or may be provided in another part as long as it is on the lower side in the vertical direction of the valve body. For example, the upstream side and the downstream side of the valve body are connected to peripheral members (portions on the lower side in the vertical direction of the valve body) of the valve body such as a frame (specifically, a valve seat (valve seat)) constituting the thermostat. A through hole that communicates with each other may be provided.

  In the present invention, an air vent jiggle valve may be provided above the valve body in the vertical direction. Thus, by providing a jiggle valve on the upper side in the vertical direction of the valve body, when cooling water is poured into the cooling device, it flows to the downstream side of the valve body through the jiggle valve (air vent hole) ( The air can be surely removed. Thereby, it is possible to prevent air from accumulating in the internal combustion engine (in the cylinder head or in the cylinder block). Such a jiggle valve may also be provided in the valve body, or may be provided in another part as long as it is above the valve body in the vertical direction. For example, a jiggle valve may be provided on a peripheral member (portion on the upper side in the vertical direction of the valve body) of the valve body such as a frame (specifically, a valve seat) constituting the thermostat.

  In the present invention, as a specific configuration of the thermostat arrangement position, the internal passage of the internal combustion engine, which communicates the cooling water passage in the block and the cooling water passage in the head (from the cooling water passage side in the block to the head). There may be mentioned a configuration in which a thermostat is provided in the vicinity of the downstream communication passage where the cooling water flows on the inner cooling water passage side. More specifically, a thermostat chamber communicating with the communication path is provided inside the internal combustion engine, and the thermostat is disposed in the thermostat chamber so that the axis of the valve body is along the horizontal direction. Further, as another configuration, a configuration in which a thermostat chamber is provided on the cooling water outlet side of the in-block cooling water passage and the thermostat is disposed in the thermostat chamber can be mentioned.

  ADVANTAGE OF THE INVENTION According to this invention, in the cooling device of the internal combustion engine provided with the thermostat which restrict | limits the flow of the cooling water in a cylinder block, the cooling water in a cylinder block can be guide | induced to the temperature sensing part of a thermostat accurately.

It is a schematic block diagram which shows an example of the cooling device of this invention. It is sectional drawing which shows an example of the thermostat for blocks used for the cooling device of FIG. FIG. 2 shows a closed state of the block thermostat. It is sectional drawing which shows an example of the thermostat for blocks used for the cooling device of FIG. FIG. 3 shows the valve open state of the block thermostat. It is a front view which extracts and shows only the valve body of the thermostat for blocks. It is a figure which shows the flow of the cooling water circulated at the time of cold in the cooling device of FIG. It is a figure which shows the flow of the cooling water which circulates in the cooling device of FIG. 1 in an engine semi-warm-up state. It is a figure which shows the flow of the cooling water circulated in the cooling device of FIG. 1 when an engine is completely warmed up. It is a figure which shows typically the flow of the cooling water in the thermostat for blocks at the time of valve closing. It is a figure which shows typically the motion of the air in the thermostat for blocks at the time of the cooling water injection. It is sectional drawing which shows the other example of the thermostat for blocks. FIG. 10 shows a closed state of the block thermostat. It is a schematic block diagram which shows the other example of the cooling device of this invention. It is a schematic block diagram which shows a part of example of a 2 system cooling device. It is a schematic block diagram which shows a part of other example of a 2 system cooling device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Embodiment 1]
A cooling device for an engine (internal combustion engine) to which the present invention is applied will be described with reference to FIG.

  In this example, a case will be described in which the present invention is applied to a two-system cooling device having a cooling water passage (head-side water jacket) inside the cylinder head of the engine and a cooling water passage (block-side water jacket) inside the cylinder block. .

  The cooling device of this example includes a water pump (W / P) 4, a heater 5, a radiator 6, a radiator thermostat 7 (hereinafter referred to as “radiator thermostat 7”), and a cylinder block thermostat 100 (hereinafter referred to as “block”). And a cooling water circulation passage 200 for circulating cooling water through these devices.

  The cooling water circulation passage 200 is configured to circulate cooling water (for example, LLC: Long Life Coolant) via the engine 1, the radiator 6, the radiator thermostat 7, and the like, and cooling water, which will be described later. The cylinder head 2 includes an in-head cooling water passage 21, a heater 5, and a heater system passage 202 that circulates through the radiator thermostat 7 and the like. In this example, one water pump 4 is used in combination for circulating the cooling water between the engine cooling system passage 201 and the heater system passage 202.

  The engine 1 is a gasoline engine or a diesel engine mounted on a conventional vehicle or a hybrid vehicle, and includes a cylinder head 2 and a cylinder block 3. A gasket 10 is mounted between the cylinder head 2 and the cylinder block 3. The gasket 10 is provided with an upstream communication path 10a and a downstream communication path 10b.

  Inside the cylinder head 2, an in-head cooling water passage (head-side water jacket) 21 is formed. Further, an in-block cooling water passage (block side water jacket) 31 is formed inside the cylinder block 3, and the in-block cooling water passage 31 and the above-mentioned head cooling water passage 21 are connected to the gasket 10. It communicates through the upstream communication path 10a. The upstream communication passage 10 a is provided in the vicinity of the cooling water inlet 31 a of the in-block cooling water passage 31. The downstream communication passage 10b of the gasket 10 is provided on the downstream side of the in-block cooling water passage 31, and the thermostat chamber 11 is provided above the downstream communication passage 10b (inside the cylinder head 2). ing. A block thermostat 100 is disposed in the thermostat chamber 11. The cooling water inlet 101a of the block thermostat 100 communicates with the cooling water passage 31 in the block through the downstream communication passage 10b. The cooling water outlet 101 b communicates with the cooling water outlet 21 b of the in-head cooling water passage 21. The details of the block thermostat 100 will be described later.

  The water pump 4 is a mechanical water pump that is connected to a crankshaft that is an output shaft of the engine 1 and is driven by the rotational driving force of the crankshaft. The discharge port 4a of the water pump 4 is connected to the cooling water inlet 31a of the in-block cooling water passage 31 of the engine 1 via the block inlet passage 201a. The cooling water outlet 21b of the in-head cooling water passage 21 is connected to the cooling water inlet 5a of the heater 5 and the cooling water inlet 6a of the radiator 6 via the head outlet passage 201b.

  The cooling water outlet 5b of the heater 5 is connected to the cooling water inlet 7a of the radiator thermostat 7 via the heater outlet passage 202a. The cooling water outlet 6b of the radiator 6 is connected to the cooling water inlet 7b of the radiator thermostat 7 through the radiator outlet passage 202b. The cooling water outlet 7c of the radiator thermostat 7 is connected to the suction port 4b of the water pump 4 via the thermo outlet passage 202c.

  The radiator thermostat 7 is a known temperature-sensitive switching valve generally used in this type of cooling device. When the valve is in a closed state, the radiator thermostat 7 is connected to a cooling water inlet 7b (radiator 6 connection port) and a cooling water outlet 7c. The cooling water inlet 7b and the cooling water outlet 7c are connected to each other when the valve is opened and the valve is open.

  Specifically, the radiator thermostat 7 is a valve device that includes a heat-sensitive portion that gives displacement to the valve body and operates by expansion and contraction of the thermo-wax in the temperature-sensitive portion, and when the cooling water temperature is relatively low, The cooling water passage between the radiator 6 and the water pump 4 is blocked (between the cooling water inlet 7b and the cooling water outlet 7c), so that the cooling water does not flow through the radiator 6. On the other hand, after the warm-up of the engine 1 is completed, that is, when the coolant temperature is relatively high, the radiator thermostat 7 opens (the coolant inlet 7b and the coolant outlet 7c communicate with each other) according to the coolant temperature. Thus, a part of the cooling water flows through the radiator 6.

  The cooling water inlet 7a (heater 5 connection port) of the radiator thermostat 7 and the cooling water outlet 7c are always in communication with each other, and the cooling water flowing from the cooling water inlet 7a toward the cooling water outlet 7c is the above temperature sensitive. It comes to contact the part.

  Further, the radiator thermostat 7 has a water temperature (for example, 82 ° C. or higher) in which the water temperature around the temperature sensing portion (≈thermo wax temperature) is higher than the valve opening temperature (for example, 70 ° C.) of the block thermostat 100 described later. The valve is set to open when

  The heater 5 is connected to the heater system passage 202, and the cooling water discharged from the water pump 4 circulates in the order of “in-head cooling water passage 21 → heater 5 → radiator thermostat 7 → water pump 4”. The heater 5 is a heat exchanger for heating the passenger compartment using the heat of the cooling water, and is disposed facing the air duct of the air conditioner. In other words, when the vehicle interior is heated (when the heater is ON), the conditioned air flowing in the air duct is passed through the heater 5 (heater core) and supplied as warm air to the vehicle interior, while at other times (for example, during cooling) When the heater is turned off, the conditioned air bypasses the heater 5.

-Thermostat for block-
Next, an example of the block thermostat 100 that is a characteristic part of this example will be described with reference to FIGS. 1 and 2 to 4.

  The block thermostat 100 in this example is a temperature-sensitive switching valve, and includes a frame 101, a valve body 102, a compression coil spring (return spring) 103, a temperature-sensitive portion 104, and the like. As shown in FIG. 1, the block thermostat 100 of this example is disposed in the thermostat chamber 11 provided in the engine 1 so that the axis (opening / closing direction) of the valve body 102 is along the horizontal direction.

  The frame (valve body) 101 is a stepped, substantially cylindrical member, and its axis is arranged along the horizontal direction. The frame 101 is held by the wall of the thermostat chamber 11. The frame 101 is provided with a cooling water inlet (opening) 101a and a cooling water outlet (opening) 101b. The frame 101 is provided with an annular valve seat (valve seat) 101c. Further, the frame 101 is provided with a spring seat 101d that receives the compression coil spring 103 on the rear side (the side opposite to the protruding side of the rod 142).

  The cooling water inlet 101a may be one or plural. In this example, a plurality of the cooling water outlets 101b are provided. The cooling water inlet 101a communicates with the inside of the in-block cooling water passage 31 shown in FIG. The cooling water outlet 101b communicates with the cooling water outlet 21b of the in-head cooling water passage 21 shown in FIG.

  The valve body 102 is provided inside the frame 101 so as to be displaceable along the horizontal direction (along the axial direction of the frame 101). That is, the valve body 102 is disposed such that its axis is along the horizontal direction. As shown in FIG. 4, the valve body 102 is a member having a circular front shape, and the block thermostat 100 is closed when the outer peripheral portion of the valve body 102 abuts on the valve seat 101 c (FIG. 2). Status). The valve body 102 is integrally attached to a case 141 of a temperature sensing unit 104 described later. Further, a compression coil spring 103 is sandwiched between the valve body 102 and the spring seat 101 d of the frame 101, and the valve body 102 is cooled by the cooling water outlet 101 b side (valve closing direction) by the elastic force of the compression coil spring 103. It is energized towards.

  The valve body 102 in this example is provided with a through hole 102a at a position vertically below the axis of the valve body 102 (axis center of the temperature sensing unit 104). The upstream side (cooling water inlet 101a side) and the downstream side (cooling water outlet 101b side) of the valve body 102 communicate with each other. In this way, the through hole 102a is provided directly below the axis of the valve body 102, and as shown in FIG. 8, between the axis of the valve body 102 (the axis of the temperature sensing portion 104) and the center of the through hole 102a. There is a difference in elevation. In addition, the valve body 102 is provided with an air vent hole 102b and a jiggle valve 105 at a position vertically above the axis of the valve body 102. 11-93666).

  The temperature sensing unit (temperature sensing cylinder) 104 is a temperature sensing actuator that applies displacement in the opening / closing direction (axial direction) to the valve body 102 and includes a case 141 and a rod 142.

  The case 141 is a cylindrical container, and is arranged so that its axis (axis of the temperature sensing unit 104) is along the horizontal direction (axis of the frame 101). The rod 142 is a rod-like member extending along the axial direction of the valve body 102 (the axis of the temperature sensing unit 104), and is slidably disposed on the case 141. The rod 142 protrudes from the case 141 toward the cooling water outlet 101b (the cooling water outlet 21b side of the in-head cooling water passage 21). The protruding end of the rod 142 is fixed to the frame 101. The valve body 102 is integrally attached to the case 141. The axis of the valve body 102 and the axis of the case 141 (the axis of the temperature sensing unit 104) coincide with each other.

  The case 141 is filled with a thermowax 143 that expands and contracts in response to heat transmitted through the wall of the case 141, and the expansion and contraction of the thermowax 143 causes the protrusion amount of the rod 142 to the case 141. It is going to change. The thermo wax 143 is sealed in the case 141 by a sealing material 144 made of rubber or the like.

  In the block thermostat 100 having the above-described structure, the valve body 102 contacts the valve seat 101c when the discharge amount of the rod 142 of the temperature sensing unit 104 (the amount of protrusion from the case 141) is the minimum ( Figure 2). From this state (valve closed state), when the temperature of the thermowax 143 in the temperature sensing unit 104 reaches a predetermined temperature or higher (valve opening temperature (eg, 70 ° C.) or higher), the thermowax 143 in the temperature sensing unit 104 expands. . Due to the expansion of the thermowax 143, the protruding amount of the rod 142 from the case 141 is increased, and the temperature sensing unit 104 and the valve body 102 are separated from the bubble sheet 101c against the elastic force of the compression coil spring 103 (opened). The block thermostat 100 is opened in a state where the valve body 102 is displaced in the valve direction) and the valve body 102 is completely separated from the bubble sheet 101c (the state shown in FIG. 3).

  Further, when the temperature of the thermowax 143 in the temperature sensing unit 104 decreases from the valve opening state shown in FIG. 3 and the thermowax 143 contracts to reduce the discharge amount of the rod 142, the elastic force of the compression coil spring 103 causes When the valve body 102 is displaced in the valve closing direction and the outer periphery of the valve body 102 is in contact with the valve seat 101c (the state shown in FIG. 2), the block thermostat 100 is closed.

  As described above, the block thermostat 100 in this example is closed when the temperature of the thermowax 143 in the temperature sensing unit 104 is lower than a predetermined temperature, thereby cooling the in-block of the engine 1 shown in FIG. The water passage 31 is closed (a minute amount of cooling water flows through the through hole 102a provided in the valve body 102), and the flow of the cooling water in the cylinder block (in-block cooling water passage 31) is restricted. On the other hand, when the temperature of the thermo wax 143 in the temperature sensing unit 104 is equal to or higher than a predetermined temperature (valve opening temperature: 70 ° C., for example), the block thermostat 100 is opened and the cylinder block 3 (in-block cooling water passage 31 is opened). ) Cooling water flows inside.

-Description of operation-
Next, the flow of the cooling water of the cooling device shown in FIG. 1 will be described with reference to FIGS. 1 and 5 to 7. The cooling water flow forms of this cooling device include “when cold”, “semi-warm-up state”, and “completely warm-up state”. FIG. 5 shows “when cold (when the cylinder block is warming up)”. FIG. 6 shows a “half warm-up state”, and FIG. 7 shows a “complete warm-up state”. 5 to 7, the passage through which the cooling water flows and the flow direction thereof are indicated by solid arrows, and the passage through which the cooling water does not flow is indicated by broken lines.

  First, when cold, the temperature of the thermowax 143 in the temperature sensing portion 104 of the block thermostat 100 is low (for example, less than 70 ° C.), so that the block thermostat 100 is closed, and the inside of the block cooling water passage 31 is closed. The flow of cooling water to the water is restricted (this state is also referred to as “in-block water stop state”). The temperature of the cylinder block 3 can be quickly raised by such a water stop state in the block, so that a cylinder friction loss or the like can be reduced, and fuel consumption can be improved.

  When the water in the block is stopped (the block thermostat 100 is closed), as shown in FIG. 5, the cooling water is [water pump 4 → cooling water inlet 31a → upstream communication path of gasket 10. 10a → head cooling water passage 21 → cooling water outlet 21b → heater 5 → radio thermostat 7 → water pump 4]. That is, the cooling water can be allowed to flow into the in-head cooling water passage 21 in a state where the flow of the cooling water in the in-block cooling water passage 31 is restricted.

  However, in this example, since the through hole 102a is provided in the valve body 102 of the block thermostat 100, the inside of the block cooling water passage 31 (inside the block thermostat 100) as shown by a two-dot chain line in FIG. A small amount of cooling water flows in Here, in this example, the axis of the valve body 102 (axial center of the temperature sensing unit 104) is along the horizontal direction, and the through hole 102a provided in the valve body 102 is below the valve body 102 in the vertical direction. Because of the difference in height between the axis of the valve body 102 (the axis of the temperature sensing portion 104) and the center of the through hole 102a, the cooling that flows in the block thermostat 100 is performed as shown in FIG. Hot water (thick line) of the water flows to the upper part (temperature sensing part 104 side) and heats the thermowax 143 in the temperature sensing part 104, while cold water (thin line) is pushed downward by the warm water and is discriminated. It flows out from the through-hole 102a of 102 to the downstream (cooling water outlet 101b side). Thus, the maximum temperature of the cooling water in the cylinder block 3 (cooling water in the block cooling water passage 31) can be sensed with high sensitivity by the temperature sensing unit 104 of the block thermostat 100.

  Next, when the engine 1 is in a semi-warm-up state (cylinder block warm-up state) and the temperature of the thermowax 143 in the temperature sensing unit 104 of the block thermostat 100 becomes equal to or higher than a predetermined temperature (valve open temperature), the block The thermostat 100 is opened. When the block thermostat 100 is opened, as shown in FIG. 6, in addition to the cooling water circulation to the in-head cooling water passage 21, the cooling water also flows into the in-block cooling water passage 31. That is, when the block thermostat 100 is opened, the cooling water is [water pump 4 → in-block cooling water passage 31 → cooling water inlet 31a → downstream communication passage 10b of the gasket 10 → block thermostat 100 → cooling water outlet 21b. → Heater 5 → Radiator thermostat 7 → Water pump 4].

  When the engine 1 is completely warmed up, as shown in FIG. 7, the radiator thermostat 7 is actuated (opened) so that a part of the cooling water flows to the radiator 6, and the cooling water is recovered. Heat is released from the radiator 6 to the atmosphere.

-Action and effect-
As described above, according to the cooling device of this example, the block thermostat 100 is disposed so that the axis of the valve body 102 (the axis of the temperature sensing unit 104) is along the horizontal direction, and the valve body 102 is arranged. Since the through hole 102a is provided on the lower side in the vertical direction, the cooling water (hot water) in the cylinder block 3 (in-block cooling water passage 31) is accurately guided to the temperature sensing part 104 of the thermostat 100 during warm-up. The maximum temperature of the cooling water in the cylinder block 3 (cooling water in the block cooling water passage 31) can be sensed with high sensitivity by the temperature sensing unit 104 of the block thermostat 100. As a result, the warm-up performance is improved.

  Further, in the cooling device of this example, since the jiggle valve 105 for venting air is provided on the upper side in the vertical direction of the valve body 102, the cooling device (in the cooling water passage 21 in the head, in the cooling water passage 31 in the block, and When cooling water is injected into the cooling water circulation passage 200, etc. (at the time of initial or maintenance cooling water injection), as shown by the solid line in FIG. 9, the air flows through the jiggle valve 105 (air vent hole 102b). Since it flows out to the downstream side of the body 102, it is possible to reliably prevent air from being accumulated in the engine 1. At the time of cooling water injection, the cooling water flows downstream through the through hole 102a on the lower side of the valve body 102, as indicated by a broken line in FIG.

-Other examples of thermostats for blocks-
Next, another example of the block thermostat will be described with reference to FIG.

  In the block thermostat 100A of this example, similarly to the thermostat 100 shown in FIGS. 2 to 4, the frame 101, the valve body 102, the compression coil spring (return spring) 103, and the temperature sensing part (temperature sensing cylinder) 104. Etc.

  In the block thermostat 100A of this example, a through-hole that communicates the upstream side and the downstream side of the valve body 102 at a position that is a valve seat (valve seat) 101c and is vertically lower than the axis of the valve body 102. 111a is provided, and the valve seat 101c is provided with an air vent hole 11b and a jiggle valve 105 at a position vertically above the axis of the valve body 102. Is basically the same as the block thermostat 100 shown in FIGS.

  Also in the block thermostat 100A of this example, when the discharge amount of the rod 142 of the temperature sensing unit 104 (the amount of protrusion from the case 141) is the minimum, the position where the valve body 102 abuts on the valve seat 101c (see FIG. The valve closing position shown in FIG. From this state (valve closed state), when the temperature of the thermowax 143 in the temperature sensing unit 104 reaches a predetermined temperature or higher (valve opening temperature (eg, 70 ° C.) or higher), the thermowax 143 in the temperature sensing unit 104 expands. . Due to the expansion of the thermowax 143, the protruding amount of the rod 142 from the case 141 is increased, and the temperature sensing unit 104 and the valve body 102 are separated from the bubble sheet 101c against the elastic force of the compression coil spring 103 (opened). The valve thermostat 100 is opened while the valve body 102 is completely separated from the bubble sheet 101c.

  In addition, when the temperature of the thermowax 143 in the temperature sensing unit 104 decreases and the thermowax 143 contracts to reduce the discharge amount of the rod 142 from such a valve-open state, the valve force is reduced by the elastic force of the compression coil spring 103. The block thermostat 100 is closed when the body 102 is displaced in the valve closing direction and the outer periphery of the valve body 102 is in contact with the valve seat 101c.

  As described above, in the block thermostat 100A in this example, the valve thermostat 100A in this example is changed from the closed state to the open state in accordance with the temperature of the thermowax 143 in the temperature sensing unit 104. Also when applied to the cooling device, the flow of the cooling water in the in-block cooling water passage 31 (cylinder block 3) of the engine 1 can be restricted during warm-up. Further, when the water in the block is stopped, the cooling water passes through the through hole 111a provided in the valve seat 101c, so that a minute amount in the block cooling water passage 31 (inside the block thermostat 100A). Therefore, the cooling water (hot water) in the cylinder block 3 (the cooling water passage 31 in the block) is supplied from the thermostat 100A during the warming-up for the same reason as described above. The temperature of the cooling water in the cylinder block 3 (cooling water in the cooling water passage 31 in the block) is sensed with high sensitivity by the temperature sensing part 104 of the block thermostat 100A. Can be warmed. As a result, the warm-up performance is improved.

[Embodiment 2]
Another example of the cooling device of the present invention will be described with reference to FIGS.

  Also in the cooling device of this example, the water pump (W / P) 4, the heater 5, the radiator 6, the radiator thermostat 7, the block thermostat 100, and these devices are cooled in the same manner as in the first embodiment. A cooling water circulation passage 200 </ b> A for circulating water is provided, and a block thermostat 100 having the same structure as that of FIGS. 2 to 4 is applied.

  In this example, the upstream communication path is not provided in the gasket 10 of the engine 1, but only the downstream communication path 10b is provided. A cooling water inlet 21 a is provided at the upstream end of the in-head cooling water passage 21 of the cylinder head 2.

  The cooling water inlet 21a of the in-head cooling water passage 21 is connected to the discharge port 4a of the water pump 4 via the head inlet passage 221a. Further, a block inlet passage 231 a is connected in the middle of the head inlet passage 221 a, and this block inlet passage 231 a is connected to the cooling water inlet 31 a of the in-block cooling water passage 31. That is, the discharge port 4a of the water pump 4 is connected to the cooling water inlet 21a of the in-head cooling water passage 21 and the cooling water inlet 31a of the in-block cooling water passage 31 (the upstream communication passage is eliminated from the gasket 10). The other configuration is basically the same as [Embodiment 1] described above.

  Also in the cooling device of this example, the flow of the cooling water in the in-block cooling water passage 31 (in the cylinder block 3) of the engine 1 can be restricted during warm-up. That is, when cold, the temperature of the thermowax 143 in the temperature sensing part 104 of the block thermostat 100 is low (for example, less than 70 ° C.), so that the block thermostat 100 is closed, and the inside of the block cooling water passage 31 is closed. The cooling water flow is limited (this state is also referred to as “in-block water stop state”). The temperature of the cylinder block 3 can be quickly raised by such a water stop state in the block, so that a cylinder friction loss or the like can be reduced, and fuel consumption can be improved.

Also in this example, since the through hole 102a is provided in the valve body 102 of the block thermostat 100, at the time of warming up (when the block thermostat 100 is closed),
As shown by a two-dot chain line in FIG. 11A, a minute amount of cooling water flows in the in-block cooling water passage 31 (inside the block thermostat 100). Therefore, for the same reason as described above, the cooling water (hot water) in the cylinder block 3 (intra-block cooling water passage 31) can be accurately guided to the temperature sensing portion 104 of the thermostat 100 during warm-up. The maximum temperature of the inside cooling water (cooling water in the block cooling water passage 31) can be sensed with high sensitivity by the temperature sensing portion 104 of the block thermostat 100.

  When the temperature sensing unit 104 of the block thermostat 100 is heated in this way and the temperature of the thermowax 143 in the temperature sensing unit 104 rises to a predetermined temperature (opening temperature) or more, the block thermostat 100 Open the valve. When the block thermostat 100 is opened, as shown in FIG. 11 (B), in addition to the cooling water circulation to the in-head cooling water passage 21, the cooling water also flows into the in-block cooling water passage 31. . Thereafter, when the engine 1 is completely warmed up, as shown in FIG. 7 described above, the radiator thermostat 7 is actuated (opened), and a part of the cooling water flows to the radiator 6. The recovered heat is released from the radiator 6 to the atmosphere.

  As described above, also in this example, the maximum temperature of the cooling water in the cylinder block 3 (cooling water in the cooling water passage 31 in the block) is determined by the temperature sensing unit 104 of the block thermostat 100 during warm-up. Sensitive to temperature. As a result, the warm-up performance is improved.

  In addition, in this example, the cooling water inlet 21a is provided in the cooling water passage 21 in the head, and the cooling water is allowed to flow positively through the cooling water passage 21 in the head (into the cooling water passage 21 in the head without passing the gasket 10). Therefore, the pressure loss of the cooling water circulation system can be reduced, and the load of the water pump 4 can be reduced. As a result, fuel consumption can be improved.

[Example of dual cooling system]
Next, an example of a two-system cooling device will be described with reference to FIGS.

  In this example, a block thermostat 100 is arranged in a thermostat chamber 12 provided in the engine 1 so that the axis of the valve body 102 (the axis of the temperature sensing unit 104) is along the vertical direction.

  The block thermostat 100 applied to this example has the same structure as that shown in FIGS. 2 to 4. Therefore, also in this example, when warming up (when the block thermostat 100 is closed), FIG. As indicated by a two-dot chain line in FIG. 5A, a minute amount of cooling water flows through the in-block cooling water passage 31. You can feel the temperature. When the temperature of the cooling water in the cooling water passage 31 in the block rises and the temperature of the thermo wax in the temperature sensing unit 104 becomes equal to or higher than a predetermined temperature (valve opening temperature), the block thermostat 100 opens, As shown in FIG. 12 (B), the cooling water also flows in the cooling water passage 31 in the block.

[Other examples of dual cooling system]
Next, another example of the dual cooling system will be described with reference to FIGS. 13 (A) and 13 (B).

  Also in this example, the block thermostat 100 is arranged such that the axis of the valve body 102 (the axis of the temperature sensing unit 104) is along the vertical direction. However, in this example, the temperature sensing portion 104 of the block thermostat 100 is disposed on the inner side of the block cooling water passage 31 and is cooled in the block during warm-up (when the block thermostat 100 is closed). The cooling water flowing in the water passage 31 (two-dot chain line in FIG. 13A) can be efficiently sensed by the temperature sensing unit 104. In this example as well, when the temperature of the cooling water in the cooling water passage 31 in the block rises and the temperature of the thermo wax in the temperature sensing unit 104 becomes equal to or higher than a predetermined temperature (valve opening temperature), the thermostat 100 for the block As shown in FIG. 13B, the cooling water flows also in the cooling water passage 31 in the block.

  In the example of FIG. 13, the cooling water inlet 101a and the cooling water outlet 101b of the block thermostat 100 are opposite to the example of FIG.

-Other embodiments-
In the above example, the block thermostat 100 is provided in the engine 1 and in the vicinity of the downstream communication passage 10b that communicates the in-block cooling water passage 31 and the in-head cooling water passage 21. Without being limited thereto, the block thermostat 100 may be arranged at another location as long as the flow of the cooling water in the block cooling water passage 31 can be limited. For example, a thermostat chamber may be provided on the cooling water outlet side of the cooling water passage in the block, and the block thermostat may be disposed in the thermostat chamber.

  In the above example, the example in which the present invention is applied to the cooling device including the mechanical water pump driven by the engine has been described. However, the present invention is not limited to this, and the present invention is also applied to the cooling device including the electric water pump. Is applicable.

  In the above example, an example in which the present invention is applied to a cooling device in which a heater (heat exchanger) is incorporated has been shown. However, in addition to the heater, for example, an exhaust heat recovery device, an EGR cooler, an ATF (Automatic Transmission fluid) The invention can also be applied to cooling systems incorporating one or more of heat exchangers such as warmers and ATF coolers. The present invention can also be applied to a cooling device in which these heaters and heat exchangers are not incorporated.

  In the above example, an example in which the present invention is applied to a cooling device for an internal combustion engine mounted on a vehicle has been described. However, the present invention is not limited to this example, and the present invention is also applied to a cooling device for an internal combustion engine other than a vehicle internal combustion engine. The invention is applicable.

  The present invention is applicable to a cooling device for an internal combustion engine (engine) mounted on a vehicle or the like, and more specifically, includes a thermostat that restricts the flow of cooling water in a cylinder block of the internal combustion engine during warm-up. It can be effectively used for a cooling device.

1 engine (internal combustion engine)
2 Cylinder head 21 Cooling water passage in the head (head side water jacket)
3 Cylinder block 31 Cooling water passage in the block (water jacket on the block side)
31a Cooling water inlet 10 Gasket 10b Downstream communication passage 4 Water pump 6 Radiator 7 Thermostat (Thermostat for radiator)
100 Thermostat (Block thermostat)
101a Cooling water inlet 101b Cooling water outlet 101c Valve seat (valve seat)
DESCRIPTION OF SYMBOLS 102 Valve body 102a Through-hole 102b Air vent hole 104 Temperature sensing part 142 Rod 143 Thermowax 105 Jiggle valve 200 Cooling water circulation passage

Claims (3)

A cooling device for cooling an internal combustion engine by circulating a cooling water, wherein an internal cooling water passage formed in a cylinder head of the internal combustion engine, and an in-block cooling water passage formed in a cylinder block of the internal combustion engine, A cooling device for an internal combustion engine comprising a thermostat for restricting a flow of cooling water in the cooling water passage in the block when the temperature of the cooling water is lower than a predetermined water temperature,
The thermostat includes a valve body and a temperature sensing part that displaces the valve body in a valve opening direction when the temperature of the cooling water reaches a predetermined temperature or more, so that the axis of the valve body is along a horizontal direction. A cooling apparatus for an internal combustion engine, wherein the thermostat is disposed, and a through hole that communicates the upstream side and the downstream side of the valve body is provided on the lower side in the vertical direction of the valve body. The cooling apparatus for an internal combustion engine according to claim 1,
A cooling device for an internal combustion engine, wherein a jiggle valve for venting air is provided on an upper side in a vertical direction of the valve body. The cooling apparatus for an internal combustion engine according to claim 1 or 2,
The cooling apparatus for an internal combustion engine, wherein the thermostat is provided in the vicinity of a communication passage that connects the in-block cooling water passage and the in-head cooling water passage inside the internal combustion engine.

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