JP5206150B2 - Engine coolant passage structure - Google Patents

Description

  The present invention relates to an engine coolant passage structure in which a thermostat valve is attached to a coolant outlet member attached to an engine.

  Conventionally, in an engine coolant passage structure including an engine having a water jacket and a radiator, an inflow port from a radiator passage communicating with the radiator with respect to a thermostat housing in which a thermostat valve is built-in There is known a configuration in which an outflow port to a suction passage communicating with a circulation pump and a bypass passage bypassing a radiator passage are communicated with each other. In this configuration, when the engine is cold, the thermostat valve closes the radiator passage side to bypass the radiator and circulate the coolant to promote engine warm-up, while when the engine is feeling warm, the thermostat valve causes the radiator to bypass the radiator. By opening the passage side and circulating the coolant via the radiator, the temperature of the coolant is set to an appropriate temperature (see, for example, Patent Documents 1 and 2).

  Here, when the engine is cold, the thermostat valve is opened and closed based on the fact that the temperature sensing part of the thermostat valve senses the temperature of the coolant flowing into the thermostat housing through the bypass passage. If the coolant flowing in through the passage flows away from the temperature sensing portion of the thermostat valve and flows out to the suction passage, it becomes difficult for the temperature sensing portion of the thermostat valve to sense the temperature of the coolant. As a result, there is an inconvenience that the opening / closing operation of the thermostat valve is not performed and the opening / closing operation is delayed even when the coolant reaches a predetermined temperature or higher.

Therefore, in the coolant passage structures disclosed in Patent Documents 1 and 2, by forming protrusions and walls in the thermostat housing, the direction of the coolant flowing into the thermostat housing from the bypass passage is forced. In this way, the coolant flows to the temperature sensing part of the thermostat valve.
Japanese Utility Model Publication No. 63-198419 Japanese Utility Model Publication No. 1-162027

  However, in the structure described in each patent document, the flow of the cooling liquid in the thermostat housing is greatly disturbed by the protrusions and walls formed in the thermostat housing, so the flow resistance of the cooling liquid increases. . This is not preferable from the viewpoint of smoothing the coolant flow.

  The present invention has been made in view of such a point, and an object of the present invention is to improve the temperature sensing accuracy of the thermostat valve without disturbing the flow of the coolant in the engine coolant passage structure including the thermostat valve. There is to increase.

According to one aspect of the present invention, the cooling liquid passage structure of the Rutotomoni attached to the engine, inlet chamber to the outlet communicating with the coolant jacket provided in the engine, radiator interposed halfway A coolant outlet member having at least an outlet port and an inlet port for the radiator passage, an outlet port for a suction passage communicating with the coolant circulation pump, and a bypass passage bypassing the radiator passage; and the coolant outlet member In the thermostat housing interposed between the inflow port for the radiator passage, the outflow port for the suction passage, and the bypass passage, and senses the temperature of the coolant in the thermostat housing. The radiator passage and the bike It comprises a thermostat valve for selectively communicating said suction passage to one of the scan path, the.

The bypass passage communicates with a bottom portion of the thermostat housing through a bottom bypass hole, and the outflow port for the suction passage communicates with the thermostat housing by opening to a peripheral side surface portion of the thermostat housing. The coolant outlet member has a temperature-sensitive bypass passage having a smaller diameter than the outlet port for the radiator passage, which bypasses the bottom bypass hole and communicates the outlet of the coolant jacket and the thermostat housing. further comprising a bypass passage for the temperature sensing, the inflow chamber and the communication position of the outlet port for the suction passage in the peripheral surface part of the thermostat housing be open to the opposite side positions, feeling the thermostat valve Drift so that the coolant flows toward the hot section. Generally by punching process is formed on the coolant outlet member by.

  According to this configuration, the thermostat valve accommodated in the thermostat housing of the coolant outlet member senses the temperature of the coolant and selectively communicates either the radiator passage or the bypass passage with the suction passage. Specifically, when the engine is cold, the thermostat valve closes the radiator passage so that the coolant flows through the bypass passage toward the suction passage, thereby bypassing the radiator passage. Then, when the temperature of the thermostat valve senses that the temperature of the coolant flowing into the thermostat housing from the bottom bypass hole exceeds the predetermined temperature, the thermostat valve bypasses the radiator passage. By closing the passage (bottom bypass hole), the coolant flows through the radiator passage toward the suction passage.

  Here, the coolant flowing into the thermostat housing from the bottom bypass hole communicating with the bottom portion of the thermostat housing does not pass through the vicinity of the temperature sensing portion of the thermostat valve, and passes through the opening that opens to the peripheral side surface portion of the thermostat housing. However, in this configuration, the temperature-sensitive bypass passage that bypasses the bottom bypass hole opens at a position opposite to the communication position of the outflow port for the suction passage on the peripheral side surface of the thermostat housing. And it forms so that a cooling fluid may flow toward the temperature sensing part of a thermostat valve. The temperature-sensing bypass passage ensures that the coolant flowing out from the outlet of the coolant jacket flows reliably in the vicinity of the temperature sensing portion of the thermostat valve. As a result, the temperature sensing accuracy of the thermostat valve is increased, and the opening / closing operation of the thermostat valve is prevented from being delayed.

  In this configuration, a temperature-sensitive bypass passage is provided between the outlet of the coolant jacket and the thermostat housing, and no protrusions or walls are provided in the thermostat housing. Thereby, the flow of the cooling liquid is not forcibly disturbed, and the flow resistance of the cooling liquid does not increase.

  Furthermore, although the temperature-sensitive bypass passage remains open even when the radiator passage is opened, the temperature-sensitive bypass passage is smaller in diameter than the outlet port for the radiator passage, and the flow resistance is Because it is much larger, when the radiator passage is open, there is almost no coolant flowing into the thermostat housing through the temperature-sensitive bypass passage, and the coolant flows toward the radiator passage. Therefore, the temperature-sensitive bypass passage does not adversely affect the flow of the coolant.

  The coolant outlet member has an opening for mounting the thermostat valve in the thermostat housing so as to be opposed to the bottom surface of the thermostat housing, and the temperature-sensitive bypass passage is formed in the thermostat housing. It is good also as being formed in the said coolant outlet member by the drilling process by the drill made to approach toward the said peripheral side part from the said opening.

  A temperature-sensitive bypass passage can be easily formed in the coolant outlet member by drilling, and drilling is performed by allowing the drill to enter from the opening of the thermostat housing toward the peripheral side surface thereof. By performing this, it is avoided that unnecessary through holes are formed in the coolant outlet member. This has an advantage that, for example, a plug for filling a hole can be omitted.

Outflow port for the front Symbol radiator passage, the cooling fluid while being positioned relative to the outlet of the jacket, so as to extend outward of the relative direction and communicating with the inlet chamber, the thermostat The housing is arranged side by side with the inflow chamber by shifting the position in a direction orthogonal to the relative direction with respect to the inflow chamber, and the bottom bypass passage branches from the inflow chamber in a direction orthogonal to the relative direction. The temperature-sensitive bypass passage may be provided so as to extend obliquely with respect to the relative direction between the thermostat housing and the inflow chamber.

  In this way, the outlet port for the radiator passage is provided straight along the outlet direction of the coolant with respect to the outlet of the coolant jacket, so that when the radiator passage is opened, its flow resistance is reduced. While suppressing, circulation of the coolant via the radiator is realized. On the other hand, as described above, since the resistance of the cooling liquid in the thermostat housing is also reduced, in this configuration, the cooling liquid circulates stably at all times.

  As described above, according to the present invention, the temperature-sensitive bypass passage is formed so as to open the peripheral side surface portion of the thermostat housing and allow the coolant to flow toward the temperature-sensitive portion of the thermostat valve. Coolant that flows out from the jacket outlet can be reliably flowed to the vicinity of the temperature sensing part of the thermostat valve, improving the temperature sensing accuracy of the thermostat valve, and avoiding delaying the opening and closing operation of the thermostat valve. Can do. Moreover, since no protrusions or walls are provided in the thermostat housing, it is possible to avoid increasing the flow resistance of the coolant.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

  1 and 2 show a water outlet member 1 as a coolant outlet member to which an engine coolant passage structure according to an embodiment of the present invention is applied. As schematically shown in FIG. 3, the water outlet member 1 is attached to the cylinder head 2 of the engine 31, whereby a water jacket 21 as a coolant jacket provided in the cylinder head 2. It connects with respect to the exit 22 of this.

  Here, the configuration of the engine coolant circulation circuit will be described with reference to FIG. 4. The coolant flowing out from the engine 31 through the outlet 22 flows into the water outlet member 1. The water outlet member 1 has an outflow port 11 and an inflow port 12 to which a radiator passage 35 having a radiator 33 interposed in the middle thereof is connected. It has an outflow port 13 to which a suction passage 36 communicating with a water pump 32 as a circulation pump to be circulated is connected. The water outlet member 1 also has an outflow port 14 to which a heater core passage 37 in which a heater core 34 for air conditioning is interposed is connected. The downstream end of the heater core passage 37 is connected to the suction passage 36 (outflow port 13).

  As will be described in detail later, the water outlet member 1 has a thermostat valve 4 and a bottom bypass passage 15 that bypasses the radiator passage 35 is formed therein.

  The thermostat valve 4 is disposed between the inflow port 12 of the radiator passage 35, the outflow port 13 of the suction passage 36, and the bottom bypass passage 15, and according to the temperature of the coolant, The bottom bypass passage 15 is selectively opened to communicate with the suction passage 36. That is, when the temperature of the coolant when the engine is cold is lower than a predetermined temperature, the thermostat valve 4 closes the radiator passage 35 and opens the bottom bypass passage 15, thereby causing the engine 31 to bypass the bottom bypass. The coolant is circulated so as to return to the engine 31 again through the passage 15 and the suction passage 36. Thus, the engine 31 is warmed up by bypassing the radiator 33 and circulating the coolant.

  On the other hand, when the temperature of the engine 31 rises and the temperature of the coolant becomes equal to or higher than the predetermined temperature, the thermostat valve 4 opens the radiator passage 35 and closes the bottom bypass passage 15. The coolant is circulated so as to return to the engine 31 again through the radiator 33 and the suction passage 36. Thus, by supplying the coolant to the radiator 33, the temperature of the coolant is set to a predetermined temperature. Note that the coolant flows through the heater core passage 37 at all times.

  Next, the configuration of the water outlet member 1 will be described with reference to FIGS. FIG. 2 shows a state in which a thermostat valve 4 and a thermo cap, which will be described later, are removed and the thermostat housing 17 is exposed. Further, FIG. 3 shows only the flow path through which the coolant flows and the portion corresponding thereto in the water outlet member 1.

  The water outlet member 1 is formed therein with an inflow chamber 16 that opens to the mounting surface side of the engine 31 and that is recessed toward the inside of the water outlet member 1. The inflow chamber 16 communicates with the outlet 22 of the water jacket 21 formed in the cylinder head 2 of the engine 31 when the water outlet member 1 is attached to the engine 31 (see FIG. 3).

  The outflow port 11 of the radiator passage 35 is formed to have a relatively large diameter, and is disposed so as to face the outlet 22 of the water jacket 21 when the water outlet member 1 is attached to the engine 31. At the same time, it communicates with the inflow chamber 16 so as to extend outward in the relative direction. Then, a pipe (not shown) is attached and connected to the outflow port 11 so that the outflow port 11 and the radiator 33 are connected to each other so that a part of the radiator passage 35 is configured. It has become.

  Thus, by providing the outflow port 11 of the radiator passage 35 straightly along the outflow direction of the coolant with respect to the outlet 22 of the water jacket 21, the resistance when the coolant flows to the radiator passage 35 side is reduced. There is an advantage that the circulation of the coolant having a relatively large flow rate through the radiator 33 is smoothed.

  The bottom bypass passage 15 has a smaller diameter than the outflow port 11 of the radiator passage 35 and extends in a direction perpendicular to the relative direction (vertical direction in FIG. 1) from the engine 31 toward the radiator. It is installed. As shown in FIG. 2, the downstream end of the bottom bypass passage 15 communicates with the peripheral side surface portion of the inflow chamber 16, while the upstream end thereof opens to the side of the water outlet member 1. The outflow port 14 for the heater core passage is configured. As described above, in the water outlet member 1, the bottom bypass passage 15 constitutes a part of the heater core passage 37.

  The water outlet member 1 is also formed with a thermostat housing 17 arranged in parallel with the inflow chamber 16 by being displaced with respect to the inflow chamber 16 in a direction perpendicular to the relative direction. The thermostat housing 17 is located above the bottom bypass passage 15 as shown in FIG. The thermostat housing 17 is also formed in the water outlet member 1 so as to open to a surface opposite to the mounting surface side of the engine 31 and to be recessed toward the inside of the water outlet member 1. As shown in FIGS. 1 and 3, the thermostat valve 4 is accommodated in the thermostat housing 17 by being inserted through the opening.

  A bottom bypass hole 18 communicating with the bottom bypass passage 15 is opened in the bottom surface portion of the thermostat housing 17, and the bottom bypass passage 15 and the thermostat housing 17 communicate with each other through the bottom bypass hole 18. Become.

  The thermostat housing 17 further communicates with the outflow port 13 for the suction passage at the peripheral side surface portion thereof. The outflow port 13 is formed to have a relatively large diameter and extends in a direction orthogonal to the relative direction. A pipe (not shown) is attached and connected to the tip of the outflow port 13 so that the outflow port 13 and the water pump 32 are connected to each other to form a suction passage 36. . 2 is a port that is formed so as to protrude from the outflow port 13 and that is connected to a pipe from the heater core 34. Thereby, as described above, the downstream end of the heater core passage 37 is connected to the outflow port 13.

  As shown in FIG. 1, in the opening of the thermostat housing 17, a thermo cap that extends in the relative direction (vertical direction in FIG. 1) with the thermostat valve 4 housed therein is fastened with, for example, a bolt or the like. It is attached by means, and this thermocap constitutes the inflow port 12 for the radiator passage. That is, by connecting and fixing a pipe (not shown) to the thermocap, the radiator 33 and the inflow port 12 are connected to each other, and a part of the radiator passage 35 is configured.

  The thermostat valve 4 is a wax type, and as shown in FIG. 1, a radiator passage side opening / closing valve 42 for opening and closing the radiator passage 35 is disposed on the upper side of the temperature sensing portion 41 filled with wax. In addition, a bottom bypass passage side opening / closing valve 43 that opens and closes the bottom bypass hole 18 that opens to the bottom surface portion of the thermostat housing 17 is disposed below the temperature sensing portion 41. Thus, when the temperature of the coolant is low, the wax contracts, so that the radiator passage side opening / closing valve 42 closes the radiator passage 35 by the biasing force of the spring, and the bottom bypass passage side opening / closing valve 43 is closed to the bottom bypass hole 18. 1 (see FIG. 1), when the temperature of the coolant is high, the valve element moves in the axial direction of the spring due to the expansion of the wax, and the radiator passage side opening / closing valve 42 opens the radiator passage 35 and the bottom bypass passage. The side opening / closing valve 43 closes the bottom bypass hole 18. Thus, one of the radiator passage 35 and the bottom bypass passage 15 is selectively opened and communicated with the outflow port 13 for the suction passage.

  Here, as in the present embodiment, the inflow port 12 of the radiator passage 35 and the bottom bypass hole 18 are arranged to face the thermostat housing 17, and the outflow port 13 of the suction passage 36 is connected to the thermostat housing 17. In the configuration communicating with the peripheral side surface portion, when the radiator passage 35 is closed, the coolant flowing into the thermostat housing 17 from the bottom bypass hole 18 as shown by the one-dot chain line arrow in FIG. 4 without passing through the vicinity of the temperature sensing portion 4, and may flow to the outflow port 13 opened in the peripheral side surface portion of the thermostat housing 17 as it is. As described above, when the coolant in the thermostat housing 17 is not sufficiently mixed, the temperature of the cooling water in the vicinity of the temperature sensing portion 41 of the thermostat valve 4 remains low. As a result, the feeling of the thermostat valve 4 This is equivalent to a decrease in temperature accuracy.

  Therefore, in the water outlet member 1 according to this embodiment, as shown in FIG. 3, a temperature-sensitive bypass passage 6 that bypasses the bottom bypass hole 18 is further provided.

  The temperature-sensitive bypass passage 6 is disposed between the inflow chamber 16 and the thermostat housing 17 so as to extend obliquely, so that the peripheral side surface portion of the inflow chamber 16, the peripheral side surface portion of the thermostat housing 17, and Are in communication with each other. More specifically, as shown in FIG. 2, the temperature-sensitive bypass passage 6 is opened on the opposite side of the peripheral side surface portion of the thermostat housing 17 from the opening position of the outflow port 13, and the height of the opening is high. The vertical position corresponds to the position of the temperature sensing part 41 of the thermostat valve 4 as shown in FIG. As a result, the coolant flowing into the thermostat housing 17 through the temperature sensing bypass passage 6 flows toward the temperature sensing portion 41 of the thermostat valve 4. As a result, the temperature sensing accuracy of the coolant in the temperature sensing part 41 of the thermostat valve 4 is increased. As a result, it is possible to avoid the fact that the thermostat valve 4 cannot sense this fact and the valve opening / closing operation is delayed although the temperature of the coolant is higher than a predetermined value.

  The diameter of the temperature-sensitive bypass passage 6 is set to be significantly smaller than the diameter of the outflow port 11 of the radiator passage 35, for example. The diameter of the temperature sensing bypass passage 6 may be set as appropriate so that the temperature sensing portion 41 of the thermostat valve 4 can secure a flow rate at which the temperature of the coolant can be sensed, but the radiator passage 35 is opened. Sometimes, the diameter of the temperature-sensitive bypass passage 6 is the outflow of the radiator passage 35 so that the coolant on the temperature-sensitive bypass passage 6 side does not interfere with the flow of the coolant to the radiator passage 35 side. It is preferable to make it significantly smaller than the diameter of the port 11.

  The temperature-sensitive bypass passage 6 is formed by drilling the water outlet member 1 formed by casting. Specifically, as shown by the dashed-dotted arrows in FIGS. 1 and 2, by inserting a drill in an oblique direction from the opening of the thermostat housing 17, the peripheral side surface portion of the inflow chamber 16 from the peripheral side surface portion of the thermostat housing 17. A through hole (temperature-sensitive bypass passage 6) extending toward the bottom is formed. By inserting a drill through the opening of the thermostat housing 17 in this manner, it is possible to avoid forming unnecessary through holes or the like in the water outlet member 1. This has an advantage that, for example, a plug or the like for closing an unnecessary through hole can be omitted.

  As described above, in the engine coolant passage structure according to this embodiment, the temperature sensing accuracy of the thermostat valve 4 is enhanced by the temperature sensing bypass passage 6, while a protrusion or a wall is provided in the thermostat housing 17. Therefore, the flow of the cooling liquid is not forcibly disturbed by such protrusions and walls, and the flow resistance of the cooling liquid is prevented from increasing. As a result, the coolant can be circulated smoothly.

  In the above-described configuration, the temperature sensing bypass passage 6 is provided so as to allow the thermostat housing 17 and the inflow chamber 16 to communicate with each other. However, in FIG. By setting to, the thermostat housing 17 may be provided so as to communicate with the upstream side of the bottom bypass passage 18 in the bottom bypass passage 15.

  As described above, the present invention is useful as a coolant passage structure for an engine because the temperature sensitive accuracy of the thermostat valve can be improved without disturbing the coolant flow.

It is sectional drawing (II sectional drawing of FIG. 2) of the water outlet member to which the engine coolant passage structure was applied. It is a top view of a water outlet member. It is explanatory drawing which extracts and shows only the flow path part of the cooling fluid in a water outlet member. It is a block diagram which shows the coolant circulation circuit of an engine.

Explanation of symbols

1 Water outlet member (coolant outlet member)
11 Outflow port for radiator passage 12 Inflow port for radiator passage 13 Outflow port for suction passage 15 Bottom bypass passage (bypass passage)
16 Inflow chamber 17 Thermostat housing 18 Bottom bypass hole 21 Coolant jacket 22 Outlet 31 Engine 32 Water pump (circulation pump)
33 Radiator 35 Radiator passage 36 Suction passage 4 Thermostat valve 41 Temperature sensing section 6 Temperature sensing bypass passage

Claims (3)

Rutotomoni attached to the engine, inlet chamber to the outlet communicating with the coolant jacket provided in the engine, the outlet port and inlet port for the radiator passage radiator is interposed halfway, the circulation of the cooling liquid An outlet port for a suction passage communicating with the pump, and a coolant outlet member having at least a bypass passage for bypassing the radiator passage;
The coolant outlet member is housed in a thermostat housing interposed between the inflow port for the radiator passage, the outflow port for the suction passage, and the bypass passage, and the coolant in the thermostat housing. A thermostat valve that senses the temperature of the radiator passage and selectively connects one of the radiator passage and the bypass passage to the suction passage,
The bypass passage communicates with a bottom surface portion of the thermostat housing through a bottom bypass hole.
The outflow port for the suction passage communicates with the thermostat housing by opening in a peripheral side surface portion of the thermostat housing,
The coolant outlet member further includes a temperature-sensitive bypass passage having a smaller diameter than the outflow port for the radiator passage, bypassing the bottom bypass hole, and communicating the outlet of the coolant jacket and the thermostat housing,
Bypass passage the temperature sensing, the inflow chamber and the communication position of the outlet port for the suction passage in the peripheral surface part of the thermostat housing be open to the opposite-side position, the temperature sensing portion of the thermostat valve A cooling fluid passage structure for an engine, wherein the cooling fluid outlet member is entirely formed by drilling with a drill so that the cooling fluid flows. The engine coolant passage structure according to claim 1,
Wherein the cooling liquid outlet member has an opening for mounting the said thermostatic valve in the thermostat housing, coolant channel structure of the Tei Ru engine is formed relative to the bottom portion of the thermostat housing. The engine coolant passage structure according to claim 2,
The outlet port for the radiator passage is disposed relative to the outlet of the coolant jacket, and communicates with the inflow chamber so as to extend outward in the relative direction.
The thermostat housing is arranged side by side with the inflow chamber by shifting the position in a direction perpendicular to the relative direction with respect to the inflow chamber,
The bottom bypass passage is branched from the inflow chamber in a direction perpendicular to the relative direction,
The temperature-sensitive bypass passage is an engine coolant passage structure that extends between the thermostat housing and the inflow chamber in an oblique direction with respect to the relative direction.

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