JP5672808B2 - Engine cooling system - Google Patents

Description

  The present invention relates to a cooling device that adjusts the temperature of an engine with a refrigerant.

  In general, when the temperature of the refrigerant is lower than a specified temperature, the engine cooling device quickly returns the refrigerant temperature to the specified temperature by setting the refrigerant taken out of the engine to return to the engine by bypassing the radiator. On the other hand, when the temperature of the refrigerant exceeds the specified temperature, the refrigerant taken out from the engine is circulated through the radiator and then returned to the engine, so that the temperature of the refrigerant falls within the specified temperature range. Try to keep on.

  Such an operation is performed by a thermostat. Although the structure of the thermostat is known, a first valve for opening or closing a valve for communicating the radiator passage and the return passage to the engine is closed, and the first valve is closed. A compression coil spring for energizing in the direction, a second valve for opening or closing the passage for bypassing the radiator and the recirculation passage, and for closing the valve to shut off, and for increasing the temperature of the refrigerant Accordingly, a thermoactuator is provided for pushing the first valve in the direction opposite to the direction of application of the spring biasing force to open the valve and simultaneously closing the second valve.

  By the way, when a single thermostat is used, it is necessary to use a thermostat having a large maximum opening area (large diameter and large opening / closing stroke) in order to increase the circulation amount of the refrigerant. It is necessary to ensure a large pipe diameter and installation space for the target refrigerant circuit. Thus, there is a problem in increasing the amount of refrigerant circulation with a single thermostat.

  On the other hand, for example, Patent Documents 1 and 2 describe the use of two thermostats.

JP 7-180555 A JP 2005-220772 A

  In Patent Document 1, as shown in paragraph 0027, one of the two thermostats is opened and closed according to a normal change in the cooling water temperature, and the remaining thermostats are cooled. It is designed for safety that opens when the water temperature rises to the upper limit.

  Further, in Patent Document 2, as shown in claim 1 and paragraph 0027, two thermostat type response valves for low temperature and high temperature are used, and separate electronic control valves are operated. Thus, the two thermostat type response valves are individually opened and closed.

  As described above, both Patent Documents 1 and 2 describe that two thermostats are used. However, as in the present invention, two thermostats are used to achieve downsizing of the entire apparatus, and total It is not configured to increase the refrigerant circulation amount as much as possible.

  In view of such circumstances, the present invention is configured to increase the total refrigerant circulation amount as much as possible while downsizing the entire apparatus using two thermostats in the engine cooling apparatus. The object is to make it possible to control the opening and closing operations of two thermostats relatively easily based on the temperature of the refrigerant without electronic control.

The present invention switches between a temperature adjustment control state in which the refrigerant taken out from the engine is distributed to the radiator and then returned to the engine, and a temperature increase control state in which the refrigerant taken out from the engine bypasses the radiator and is returned to the engine. The flow path switching unit includes a housing having a room partitioned vertically in the vertical direction, and two communication holes provided in series in the refrigerant flow direction in the partition part of the two rooms. Two thermostats to be incorporated, and the lower chamber is provided with a first inlet through which the refrigerant taken out from the engine and passed through the radiator is introduced, and the upper chamber is taken out from the engine and is provided with the radiator. A second inlet through which the refrigerant bypassed is introduced, and an outlet for returning the refrigerant to the engine, Serial Both thermostats includes a frame central hole matching the communicating hole of the partition portion is provided, a first valve provided to allow opening and closing the central hole matching the prior Killen hole in the frame, the first 1 and a compression coil spring for urging the first valve so as to close the central hole matching the prior Killen holes in the valve, a second valve provided to allow opening and closing the second inlet, the upper the same time closing a center hole in which the temperature of the refrigerant of the supported on the frame and in the upper room matches before Killen hole in the first valve when less than the predetermined temperature so as to be arranged in the room second while ensuring the temperature increase promotion control state by opening the second inlet in the valve, meets before Killen hole in the first valve when the temperature of the refrigerant in the upper room above the specified temperature Opening the Kokoroana When a thermo-actuator to secure the temperature control state by closing the second inlet in said second valve simultaneously, wherein the refrigerant flow direction upstream side of the thermostat, begins to open the first valve The center position of the region is arranged at a predetermined angular position on the circumference with respect to a virtual straight line passing through the centers of the two communication holes in the partition portion.

  In this configuration, since two thermostats are used instead of a single thermostat, the two thermostats have a relatively small maximum opening area compared to the case where a single thermostat is used (both aperture and opening / closing stroke). It is possible to reduce the size of the housing and to reduce the installation space.

  Further, as will be described below, the opening and closing operations of the two thermostats can be controlled relatively easily not by electronic control but by the temperature of the refrigerant.

  First, when the temperature of the refrigerant taken out from the engine is lower than the specified temperature, each first valve of both thermostats closes the center hole of the frame and the communication hole of the partition portion, and at the same time, the second valve opens the second inlet. Since the upper chamber and the lower chamber are shut off, the refrigerant taken out from the engine flows from the second inlet to the outlet through the upper chamber. That is, in this case, the refrigerant taken out from the engine is circulated in the bypass path → second inlet → upper chamber → exit → return path → engine path. In this circulation mode, since the refrigerant does not flow into the radiator, the temperature of the refrigerant is raised relatively early.

  When the temperature of the refrigerant flowing into the upper chamber from the second inlet becomes equal to or higher than the specified temperature, the first valves of the two thermostats open the center hole of the frame and the communication hole of the partition portion, and the second valve is second. Since the inlet is closed, the upper chamber and the lower chamber communicate with each other, and the refrigerant taken out from the engine flows from the first inlet to the outlet through the lower chamber and the upper chamber. That is, in this case, the refrigerant taken out from the engine is circulated through the radiator, the heat exchange path, the first inlet, the lower chamber, the upper chamber, the outlet, the reflux path, and the engine path. In this circulation mode, the refrigerant passes through the radiator, so that the temperature of the refrigerant is maintained at a specified temperature.

  In addition, when the first valves of the two thermostats start to open as described above, if a relatively low temperature refrigerant flows into the lower chamber from the first inlet, the two relatively low temperature refrigerants It flows into the upper chamber from an opening formed by each first valve of the thermostat and each communication hole of the partition. At that time, it is assumed that most of the relatively low-temperature refrigerant flowing into the upper chamber from the opening formed by the first valve of the upstream thermostat and the upstream communication hole of the partition directly collides with the thermoactuator of the downstream thermostat. Assuming that this is the case, the second valve opens the second inlet at the same time as the first valve of the downstream thermostat closes the downstream communication hole of the partition. Accordingly, relatively high-temperature refrigerant flows into the upper chamber from the second inlet, and this relatively high-temperature refrigerant collides with the thermoactuator of the downstream thermostat, so that the first valve of the downstream thermostat again. However, the second valve closes the second inlet simultaneously with opening the downstream side communication hole of the partition.

  As described above, when the first valve and the second valve of the downstream thermostat are repeatedly opened and closed, there is a concern that the amount of refrigerant flowing from the first inlet → the lower chamber → the upper chamber → the outlet decreases. . It is considered that this open / close repeated phenomenon is likely to occur until the temperature of the refrigerant flowing into the first inlet reaches a specified temperature or higher.

  On the other hand, when the configuration of the present invention is adopted, the first valves of the two thermostats start to open the communication holes of the partition portion, and at the same time, the second valves start to close the second inlet. Sometimes, a relatively low-temperature refrigerant flows into the lower chamber from the first inlet, and then flows into the upper chamber through an opening formed by the first valve of the upstream thermostat and the upstream communication hole of the partition. However, most of the relatively low-temperature refrigerant entering the upper chamber flows in a detour without directly colliding with the thermoactuator of the downstream thermostat.

  As a result, the first valve of the downstream thermostat closes the downstream communication hole of the partition portion, and at the same time, the second valve does not operate to open the second inlet, and the first valves of the two thermostats begin to open. Therefore, the occurrence of the phenomenon that the first valve of the downstream side thermostat repeatedly opens and closes as described above can be avoided. The first valve of the side thermostat can be quickly transferred to the fully open state.

  In this way, when the first valves of the two thermostats start to open, it becomes possible to quickly synchronize and shift to the fully open state, so that the first inlet → the lower room → the upper room → the outlet It is possible to quickly maximize the amount of refrigerant flowing into the radiator, and to stably distribute a large amount of refrigerant to the radiator. As a result, it is possible to quickly and stably transition from the temperature increase promotion control state in which the temperature of the refrigerant is raised to the specified temperature to the temperature adjustment control state in which the refrigerant is maintained at the specified temperature. It is possible to prevent this phenomenon.

  Preferably, each frame of the two thermostats has a ring plate having the center hole, and a jiggle valve is provided at a predetermined circumferential position of each ring plate, and the compression coil of the upstream thermostat The first valve side end of the spring is arranged at an arbitrary position in the circumferential direction with the existing position of the jiggle valve as a reference position, and the center position of the opening start region of the first valve is the presence of the jiggle valve The position is specified as the reference position.

  In this configuration, when assembling the upstream thermostat to the upstream communication hole of the partition, the center position of the opening start region by the first valve of the upstream thermostat is positioned on the ring plate of the upstream thermostat frame. The existing position of the installed jiggle valve is used as a reference position. As a result, there is no need to provide a special alignment mark or positioning structure, which is advantageous in suppressing an increase in equipment cost.

  Preferably, the two thermostats have the same specifications. When the two thermostats have the same specifications in this way, it is possible to suppress an increase in the manufacturing cost of the cooling device, such as being able to purchase at a relatively low cost by mass purchase at the production site.

  Further, as will be described below, the opening and closing operations of the two thermostats can be relatively easily synchronized not by electronic control but by the temperature of the refrigerant.

  In other words, when the first valves of the two thermostats start to open as described above, if a relatively low temperature refrigerant flows into the lower chamber from the first inlet, the two relatively low temperature refrigerants It flows into the upper chamber from an opening formed by each first valve of the thermostat and each communication hole of the partition. At that time, it is assumed that most of the relatively low-temperature refrigerant flowing into the upper chamber from the opening formed by the first valve of the upstream thermostat and the upstream communication hole of the partition directly collides with the thermoactuator of the downstream thermostat. Assuming that this is the case, the second valve opens the second inlet at the same time as the first valve of the downstream thermostat closes the downstream communication hole of the partition. Accordingly, relatively high-temperature refrigerant flows into the upper chamber from the second inlet, and this relatively high-temperature refrigerant collides with the thermoactuator of the downstream thermostat, so that the first valve of the downstream thermostat again. However, the second valve closes the second inlet simultaneously with opening the downstream side communication hole of the partition.

  As described above, when the first valve and the second valve of the downstream thermostat are repeatedly opened and closed, there is a concern that the amount of refrigerant flowing from the first inlet → the lower chamber → the upper chamber → the outlet decreases. . It is considered that this open / close repeated phenomenon is likely to occur until the temperature of the refrigerant flowing into the first inlet reaches a specified temperature or higher.

  On the other hand, when the configuration of the present invention is adopted, the first valves of the two thermostats start to open the communication holes of the partition portion, and at the same time, the second valves start to close the second inlet. Sometimes, a relatively low-temperature refrigerant flows into the lower chamber from the first inlet, and then flows into the upper chamber through an opening formed by the first valve of the upstream thermostat and the upstream communication hole of the partition. However, most of the relatively low-temperature refrigerant entering the upper chamber flows in a detour without directly colliding with the thermoactuator of the downstream thermostat.

  As a result, the first valve of the downstream thermostat closes the downstream communication hole of the partition portion, and at the same time, the second valve does not operate to open the second inlet, and the first valves of the two thermostats begin to open. Therefore, the occurrence of the phenomenon that the first valve of the downstream side thermostat repeatedly opens and closes as described above can be avoided. The first valve of the side thermostat can be quickly transferred to the fully open state.

  In this way, when the first valves of the two thermostats start to open, it becomes possible to quickly synchronize and shift to the fully open state, so that the first inlet → the lower room → the upper room → the outlet It is possible to quickly maximize the amount of refrigerant flowing into the radiator, and to stably distribute a large amount of refrigerant to the radiator. As a result, it is possible to quickly and stably transition from the temperature increase promotion control state in which the temperature of the refrigerant is raised to the specified temperature to the temperature adjustment control state in which the refrigerant is maintained at the specified temperature. It is possible to prevent this phenomenon.

  The engine cooling apparatus according to the present invention makes it possible to increase the total refrigerant circulation amount as much as possible while downsizing the entire apparatus using two thermostats. The opening / closing operation can be controlled relatively easily based on the refrigerant temperature without electronic control.

It is a figure which shows the schematic structure in one Embodiment of the cooling device of the engine which concerns on this invention. It is sectional drawing which shows the flow-path switching part of FIG. It is a perspective view which decomposes | disassembles and shows the housing of the flow-path switching part of FIG. FIG. 4 is a cross-sectional view taken along line (4)-(4) in FIG. 2, showing a state in which the thermostat thermowax is coagulated and contracted and the first valve is closed. FIG. 5 is a view corresponding to FIG. 4, showing a state in which the thermostat thermowax is melted and expanded and the first valve is opened. It is an arrow view of the (6)-(6) line cross section of FIG. It is a perspective view which shows the thermostat single-piece | unit of FIG. It is the figure which looked at the thermostat of FIG. 7 from the bottom. It is the figure which looked at the thermostat of FIG. 7 from the top. It is a perspective view which shows the cylindrical compression coil spring single-piece | unit of the thermostat of FIG. It is sectional drawing of the thermostat single-piece | unit of FIG. It is a figure for demonstrating a mode when a 1st valve begins to open in FIG. It is a figure corresponding to FIG. 6, and is a figure for demonstrating the positioning form at the time of assembling at least an upstream thermostat.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings.

  1 to 13 show an embodiment of the present invention. In the following description, “upstream” and “downstream” are based on the refrigerant flow direction.

  As shown in FIG. 1, the cooling device for the engine 1 includes a water pump 2, a radiator 3, a heat exchange path 4, a reflux path 5, a bypass path 6, a flow path switching unit 10, and the like.

  The water pump 2 is driven by the engine 1 so that a coolant such as cooling water in the engine 1 is once taken out to the heat exchange path 4 and the bypass path 6 and then circulated so as to return to the engine 1. It is. The water pump 2 can also be an electric type.

  The radiator 3 is installed in the middle of the heat exchange path 4, and cools by dissipating the heat of the refrigerant.

  The heat exchange path 4 is a flow path for circulating the refrigerant taken out from the engine 1 by the water pump 2 to the radiator 3. On the upstream side of the radiator 3 in the heat exchange path 4, an air vent drain 7 is provided.

  The reflux path 5 is a flow path for returning the refrigerant taken out from the engine 1 by the water pump 2 to the engine 1.

  The bypass path 6 is a flow path for guiding the refrigerant taken out from the engine 1 by the water pump 2 to the reflux path 5 by bypassing the radiator 3. The upstream end of the bypass path 6 is connected to the upstream side of the heat exchange path 4.

  The flow path switching unit 10 causes the refrigerant taken out from the engine 1 to flow from the downstream of the heat exchange path 4 to the recirculation path 5 to keep the refrigerant at a specified temperature, or the refrigerant taken out from the engine 1 from the bypass path 6. This is an apparatus for ensuring a temperature rise promotion control state in which the temperature of the refrigerant is increased by flowing through the reflux path 5.

  In this embodiment, the heater for taking out the refrigerant from the upstream side of the heat exchange path 4 and flowing it through the heater core 8 installed in the vehicle compartment and then flowing it through the upper chamber 24 of the flow path switching unit 10 to the reflux path 5. A passage 9 is provided. Further, a degas bottle (pressurized reserve tank) 11 is connected to the upper chamber 24 of the flow path switching unit 10 via a relay path 12.

  The degas bottle 11 is a container serving as a refrigerant pool for absorbing expansion and contraction of the refrigerant accompanying the temperature change of the refrigerant in the cooling apparatus according to the present invention and a pool of air mixed in the cooling apparatus. An air opening (not shown) is provided at the uppermost position of the degas bottle 11, and a pressure cap (not shown) is attached to the upper atmosphere opening. For example, when the refrigerant is introduced into the degas bottle 11 when replacing the refrigerant of the cooling device, or when the air in the degas bottle 11 is released to the outside, the pressure cap is removed.

  Next, the flow path switching unit 10 will be described in detail with reference to FIGS. The flow path switching unit 10 includes a housing 20, two thermostats 30 and 40, and the like.

  Specifically, in this embodiment, the housing 20 has a two-piece structure in which a lower housing 21 and an upper housing 22 are combined, and rooms 23 and 24 that are partitioned vertically in the form described below are provided. ing.

  The lower housing 21 includes a body 211 that is recessed downward, a cylindrical first inlet 212 that protrudes laterally outward from one longitudinal end of the bottom wall of the body 211, and a lid that is provided on an elliptical upper opening edge of the body 211. And a partition portion 213 having a shape.

  The first inlet 212 is connected to the downstream end of the heat exchange path 4. The partition part 213 is formed in a substantially rectangular flat plate shape when viewed from above, and two communication holes 214 and 215 penetrating in the thickness direction (vertical direction) are arranged in the partition part 213 in the longitudinal direction. Is provided.

  The upper housing 22 has a body 221 that is recessed upward, a cylindrical outlet 222 that protrudes laterally outward from one short side wall of the body 221, and an outwardly upward protrusion from two locations aligned in the longitudinal direction on the ceiling wall of the body 221. A second inlet 223 having a shape that merges and protrudes laterally, a cylindrical third inlet 224 that protrudes outward from the longitudinal center in the ceiling wall of the body 221, and a longitudinal end of the ceiling wall of the body 221 from one end in the longitudinal direction A cylindrical fourth inlet 225 that protrudes outward and upward and an outward flange 226 provided at the lower opening edge of the oval shape of the body 221 are provided.

  The outlet 222 is connected to the upstream end of the reflux path 5, the second inlet 223 is connected to the downstream end of the bypass path 6, the third inlet 224 is connected to the downstream end of the heater passage 9, and the fourth inlet The downstream end of the relay path 12 from the degas bottle 11 is connected to the inlet 225.

  And the partition part 213 of the lower housing 21 and the outward flange 226 of the upper housing 22 are overlapped, and they are fastened by a plurality of bolts 25.

  The partition portion 213 is provided with an insertion hole (reference numeral omitted) through which the bolt 25 is loosely inserted and penetrates in the thickness direction, and the outward flange 226 penetrates in the thickness direction and the bolt 25 is inserted. A female screw hole (reference numeral omitted) to be screwed is provided. Accordingly, the concave portion of the body 211 of the lower housing 21 becomes the lower chamber 23, the concave portion of the upper housing 22 becomes the upper chamber 24, and the partition portion 213 of the lower housing 21 separates the lower chamber 23 and the upper chamber 24. It becomes a partition.

  By attaching the thermostats 30 and 40 to the two communication holes 214 and 215 of the partition part 213, the two communication holes 214 and 215 are individually opened and closed by the two thermostats 30 and 40. As a result, the two thermostats 30 and 40 are arranged in series in the direction in which the refrigerant introduced from the first inlet 212 or the second inlet 223 flows toward the outlet 222. Accordingly, the lower chamber 23 is positioned on the upstream side in the refrigerant flow direction, and the upper chamber 24 is positioned on the downstream side in the refrigerant flow direction.

  By the way, the installation position in the vertical direction of each element constituting the cooling device in this embodiment is assumed to be set to a relationship as shown in FIG.

  Next, the two thermostats 30 and 40 will be described in detail with reference to FIGS. 2 and 4 to 11.

  The two thermostats 30 and 40 have the same specifications (external shape, components, maximum opening area, etc.). Both the thermostats 30 and 40 include frames 31 and 41 (see FIGS. 2 and 7), thermoactuators 32 and 42, first valves 33 and 43, cylindrical compression coil springs 34 and 44, and second valves 35 and 45. And conical compression coil springs 36, 46, and the like.

  The frames 31 and 41 are configured such that arches 312 and 412 are provided above the ring plates 311 and 411 and arches 313 and 413 are provided below the ring plates 311 and 411. Jiggle valves 314 and 414 are provided at predetermined circumferential positions of the ring plates 311 and 411. The function of the jiggle valves 314 and 414 is to finely send bubbles flowing into the lower chamber 23 and send them out to the upper chamber 24.

  The thermoactuators 32 and 42 are driving sources for sensing the temperature change of the refrigerant and simultaneously raising and lowering the first valves 33 and 43 and the second valves 35 and 45, and are supported by the frames 31 and 41. ing. The thermoactuators 32 and 42 include bottomed cylindrical thermal cylinders 321 and 421, cylindrical guide members 322 and 422, push rods 323 and 423, elastic seal spools 324 and 424, thermowax 325 and 425, and the like. Yes.

  The guide members 322 and 422 are attached to the lower openings of the thermal cylinders 321 and 421, and the lower sides of the push rods 323 and 423 are guided by the guide members while the upper sides of the push rods 323 and 423 are placed in the thermal cylinders 321 and 421. 322 and 422 are inserted into the center holes so as to protrude downward from the lower openings of the thermal cylinders 321 and 421, and elastic seal spools 324 and 424 are attached to the guide members 322 and 422, and the thermal cylinders 321 and 421 are attached. Thermo-wax 325 and 425 are filled in an internal sealed space between the elastic seal spools 324 and 424.

  The thermowaxes 325 and 425 change to a state of solidification and shrinkage or a state of melting and expansion according to a change in the temperature of the thermal cylinders 321 and 421, and generally known ones are used. The first valves 33 and 43 are attached between the outer periphery of the lower opening of the thermal cylinders 321 and 421 and the outer periphery of the guide members 322 and 422, and the second valve 35, 45 is attached in a state in which it is prevented from coming off by a retaining ring (reference numeral omitted).

  The thermoactuators 32 and 42 are incorporated between the upper arches 312 and 412 and the lower arches 313 and 413 of the frames 31 and 41. The upper ends of the push rods 323 and 423 are fixed to the centers of the upper arches 312 and 412, the thermal cylinders 321 and 421 are supported by the lower arches 313 and 413 so as to be relatively displaceable, and the first valves 33 and 43 are connected to the ring plates 311 and 431. It arrange | positions so that the center hole (code | symbol abbreviation) of 411 may be opened or closed. The state in which the first valves 33 and 43 open the center holes of the ring plates 311 and 411 is the valve open state, and the closed state is the valve closed state.

  The ring plates 311 and 411 are in contact with the periphery of the communication holes 214 and 215 on the upper surface of the partition part 213 so that the center holes thereof match the two communication holes 214 and 215 of the partition part 213 of the lower housing 21. Is done. Thereby, the center holes of the ring plates 311 and 411 and the two communication holes 214 and 215 of the partition part 213 serve as holes for communicating the lower chamber 23 and the upper chamber 24 of the housing 20. Jiggle valves 314 and 414 provided on the ring plates 311 and 411 are arranged on the inner diameter side of the two communication holes 214 and 215 of the partition part 213.

  Cylindrical compression coil springs 34 and 44 are interposed between the first valves 33 and 43 and the lower arches 313 and 413 in an elastically compressed state. With the elastic restoring force, the first valves 33 and 43 are pressed against the ring plates 311 and 411 so as to close the center holes of the ring plates 311 and 411.

  The conical compression coil springs 36 and 46 are interposed between the bottoms of the thermal cylinders 321 and 421 and the second valves 35 and 45 in an elastically compressed state, and the conical compression coil springs 36 and 46. With the elastic restoring force, the second valves 35 and 45 are pressed against the second inlet 223 of the upper housing 22 so as to close the second inlet 223.

  Next, the basic operation of the cooling device will be described.

  First, when the refrigerant taken out from the engine 1 is lower than a specified temperature (for example, warm-up completion temperature) as in the cold start of the engine 1, the relatively low-temperature refrigerant passes from the bypass 6 to the second inlet 223 of the housing 20. Will flow into the upper room 24.

  That is, when the periphery of the thermowaxes 325 and 425 of the two thermostats 30 and 40 is lower than the specified temperature, the thermowaxes 325 and 425 are solidified and contracted to reduce the wax pressure, so that the elastic seal spools 324 and 424 are The fitting depth of the heat-sensitive cylinders 321 and 421 with respect to the push rods 323 and 423 is increased. As a result, the cylindrical compression coil springs 34 and 44 and the conical compression coil springs 36 and 46 expand together, and the first valves 33 and 43 are pressed against the ring plates 311 and 411 as shown in FIG. The first valves 33 and 43 are closed so as to close the center holes and the communication holes 214 and 215 of the ring plates 311 and 411, while the second valves 35 and 45 are separated from the second inlet 223 to be in the second inlet 223. Open the valve to open.

  Therefore, in this state, the refrigerant taken out from the engine 1 flows into the upper chamber 24 from the bypass 6 through the second inlet 223 of the housing 20 as indicated by the solid arrow A in FIG. The refrigerant flowing into the upper chamber 24 is discharged from the outlet 222 of the housing 20 to the reflux path 5 and returned to the engine 1. That is, the refrigerant is circulated in the route of the engine 1 → the bypass path 6 → the second inlet 223 → the upper chamber 24 → the outlet 222 → the return path 5 → the engine 1. In this circulation mode, since the refrigerant does not flow into the radiator 3, the temperature of the refrigerant is quickly raised by the heat of the engine 1. This state is a temperature increase promotion control state.

  When air is collected in the lower chamber 23 of the flow path switching unit 10 in a state where the refrigerant circulates in such a temperature rise promotion control state, this air is a jiggle valve of the two thermostats 30 and 40. After being sent out to the upper room 24 while being made fine by 314 and 414, it is stored in the degas bottle 11 through the fourth inlet 225 and the relay path 12.

  Thereafter, in a state where the refrigerant taken out from the engine 1 flows into the upper chamber 24 from the bypass passage 6 through the second inlet 223 of the housing 20 and flows out from the outlet 222 to the reflux passage 5, the temperature of the refrigerant is reduced. When the temperature is higher than the specified temperature, the relatively high temperature refrigerant comes into contact with the thermowaxes 325 and 425 of the two thermostats 30 and 40.

  As a result, the thermowaxes 325 and 425 of the two thermostats 30 and 40 are melted and expanded to increase the wax pressure, so that the elastic seal spools 324 and 424 are squeezed and the push rods 323 and 423 are fitted to the thermal cylinders 321 and 421. The mating depth becomes shallower. As a result, the thermal cylinders 321 and 421 are lifted, so that the first valves 33 and 43 are pulled away from the ring plates 311 and 411 while compressing the cylindrical compression coil springs 34 and 44 as shown in FIG. At the same time that the central holes and the communication holes 214 and 215 of the plates 311 and 411 are opened, the second valves 35 and 45 are pressed against the second inlet 223 to close the second inlet 223. . At this time, the conical compression coil springs 36 and 46 are compressed, and the second valves 35 and 45 are brought into pressure contact with the second inlet 223 by the elastic restoring force.

  In this state, the refrigerant taken out from the engine 1 flows into the radiator 3 through the heat exchange path 4 as shown by a one-dot chain line arrow B in FIG. 1, and the refrigerant that has passed through the radiator 3 passes through the radiator 20 in the housing 20. 1 flows into the lower chamber 23 through the inlet 212, and further flows into the upper chamber 24 from the lower chamber 23 through the center holes of the ring plates 311 and 411 and the communication holes 214 and 215 of the partition part 213, 20 is discharged from the outlet 222 to the reflux path 5 and returned to the engine 1.

  That is, the refrigerant is circulated in the route of the engine 1 → the heat exchange path 4 → the first inlet 212 → the lower chamber 23 → the upper chamber 24 → the outlet 222 → the reflux path 5 → the engine 1. In this circulation mode, the refrigerant flows into the radiator 3 and is cooled, so that the temperature of the refrigerant is maintained at a specified temperature. This state is a temperature adjustment control state.

  However, since the thermostats 30 and 40 are steplessly displaced in the axial direction in the guide members 322 and 422 and the thermal cylinders 321 and 421 with respect to the push rods 323 and 423 in accordance with the temperature of the refrigerant flowing into the upper chamber 24, The opening areas of the center holes of the ring plates 311 and 411 and the communication holes 214 and 215 of the partition part 213 by the first valves 33 and 43 are adjusted steplessly according to the displacement position. As a result, the refrigerant taken out from the engine 1 is distributed to the heat exchange path 4 and the bypass path 6, and the amount of refrigerant flowing to the radiator 3 is adjusted, so that the temperature of the refrigerant is adjusted. The

  By the way, as described above, the refrigerant is heated up to a specified temperature or higher by being circulated through the route of the engine 1 → the bypass 6 → the second inlet 223 → the upper chamber 24 → the outlet 222 → the return passage 5 → the engine 1 When both the first valves 33 and 43 start to open the center hole and the communication holes 214 and 215 and at the same time the second valves 35 and 45 start to close the second inlet 223, the refrigerant taken out from the engine 1 exchanges heat. In order to flow into the radiator 3 via the path 4, the relatively low temperature refrigerant remaining in the heat exchange path 4 and the radiator 3 flows into the lower chamber 23 from the first inlet 212.

  The relatively low-temperature refrigerant flowing into the lower chamber 23 flows into the upper chamber 24 through the center holes of the ring plates 311 and 411 and the two communication holes 214 and 215 of the partition part 213.

  However, at that time, most of the relatively low-temperature refrigerant flowing into the upper chamber 24 through the opening formed by the first valve 33 of the upstream thermostat 30 and the upstream communication hole 214 of the partition 213 is downstream. Assuming that the thermostat 42 directly collides with the thermoactuator 42 of the thermostat 40, the thermowax 425 of the thermoactuator 42 of the downstream thermostat 40 immediately coagulates and contracts from the state where it has melted and expanded. Since the wax pressure is lowered, the first valve 43 closes the communication hole and the upstream communication hole 215 and the second valve 45 opens the second inlet 223 at the same time.

  In this case, the relatively high-temperature refrigerant remaining in the bypass passage 6 flows into the upper chamber 24 through the second inlet 223 of the housing 20 and collides with the thermoactuator 42 of the downstream thermostat 40. As a result, the thermowax 425 of the thermoactuator 42 melts and expands from the state in which the thermowax 425 is solidified and contracted, and the first valve 43 opens the center hole and the upstream side communication hole 215 of the ring plate 411 again. At the same time, the second valve 45 closes the second inlet 223.

  As described above, the phenomenon that the operation of opening and closing the first valve 43 and the second valve 45 by the thermoactuator 42 of the downstream thermostat 40 occurs, and the first inlet 212 → the lower chamber 23 → the upper chamber 24 → the outlet. There is a concern that the amount of refrigerant flowing to 222 will be reduced.

  This phenomenon is that the relatively low temperature refrigerant remaining in the heat exchange path 4 and the radiator 3 is taken out from the engine 1 until the temperature of the refrigerant flowing into the first inlet 212 becomes equal to or higher than the specified temperature. It is considered that there is a high possibility that it will occur until it is pushed out by the refrigerant at a temperature or higher. When the occurrence of this phenomenon is prolonged, it takes time to completely shift from the temperature increase promotion control state in which the refrigerant is heated to the specified temperature to the temperature adjustment control state in which the refrigerant is maintained at the specified temperature. There is a concern that the possibility that the refrigerant may overheat temporarily increases.

  Based on such knowledge, in the embodiment according to the present invention, the first valves 33 and 43 of the two thermostats 30 and 40 are connected to the center hole of the ring plates 311 and 411 and the communication hole 214 of the partition part 213 as described above. , 215 starts opening the relatively low temperature refrigerant remaining in the heat exchange path 4 and the radiator 3 by the first valve 33 of the upstream thermostat 30 and the upstream communication hole 214 of the partition portion 213. When flowing into the upper chamber 24 through, the most of the relatively low-temperature refrigerant that has flowed into the upper chamber 24 is detoured without directly colliding with the thermoactuator 42 of the downstream thermostat 40. Yes.

  The reason for coming up with such a technical idea will be explained.

  In the first place, in the case of the thermostats 30 and 40 configured as described above, the first valves 33 and 43 are caused by the contact state of the lower end portions (first valve side end portions) of the cylindrical compression coil springs 34 and 44. When the opening starts, the entire circumferential area may not open simultaneously but may start from a predetermined angular range on the circumference.

  The reason will be described with reference to FIGS. In general, the purpose is to seat both upper and lower ends of cylindrical compression coil springs 34 and 44 against the first valves 33 and 43 and the upper arches 312 and 412 which are in contact with each other in as wide an area as possible. As shown in FIG. 10, for example, the both ends are subjected to planar processing.

  However, even if such planar processing portions 34a and 44a are provided, in an actual assembled state, as shown in FIG. 11, for example, cylindrical compression coil springs 34 and 44 are appropriately separated from the planar processing portions 34a and 44a. The winding region without plane machining may be in a state of floating from the first valves 33 and 43 and the upper arch 312 (including a non-contact state or a light contact state). Reference numerals 34b and 44b are attached to the floating region without the flat surface processing.

  In this floating state, when the first valves 33 and 43 start to open due to the thermowax 325 and 425 being melted and expanded, the valve opening load (lower chamber 23) is applied to the first valves 33 and 43. Even if the refrigerant pressure is evenly applied, as shown in FIG. 12, for example, the entire peripheral area of the first valves 33 and 43 does not open at the same time. The first valves 33 and 43 are inclined in an oblique posture, starting from the winding regions 34b and 44b) where the springs 34 and 44 are lifted first. A predetermined angle range on the circumference (the winding regions 34b and 44b where the cylindrical compression coil springs 34 and 44 float) is referred to as a first opening region 100 of the first valves 33 and 43.

  For this reason, when the first valves 33 and 43 start to open, the refrigerant in the lower chamber 23 passes through a predetermined angular range (opening start region 100) on the circumference of the first valves 33 and 43, and the upper chamber 24 is opened. To flow into. For this reason, it can be said that there is a bias in the direction of refrigerant flow from the lower chamber 23 to the upper chamber 24.

  Incidentally, the direction of the imaginary straight line 105 (described in FIG. 13) that begins to open from the center of the upstream communication hole 214 by the first valve 33 of the upstream thermostat 30 and passes through the center position 101 of the region 100 is indicated by the thermoactuator of the downstream thermostat 40. When the flow path switching unit 10 is assembled in a state of being opposed to 42, the opening formed by the first valve 33 of the upstream thermostat 30 and the upstream communication hole 214 of the partitioning unit 213, as described above. Most of the relatively low-temperature refrigerant flowing into the upper chamber 24 through the air easily collides with the thermoactuator 42 of the downstream thermostat 40.

  The inventors of the present application paid attention to the deviation in the direction of refrigerant inflow as described above and thought that it is possible to bypass the refrigerant as described above by using this deviation.

  Next, in order to realize the technical idea, in the embodiment according to the present invention, for example, as shown in FIG. 13, a lower end portion (first valve side end portion) of a cylindrical compression coil spring 34 provided in the upstream thermostat 30. ), The center position 101 of the opening start region 100 of the first valve 33 (the center position in the winding direction of the winding region 34b floating from the first valve 33 in the cylindrical compression coil spring 34) due to the arrangement position of the planar processing portion 34a. The virtual straight line 102 passing through the centers of the two communication holes 214 and 215 of the partition part 213 is arranged at a predetermined angle α on the circumference.

  In other words, with respect to the central position 101 of the region 100 where the first valve 33 of the upstream thermostat 30 starts to open, most of the refrigerant flowing through the region into the upper chamber 24 directly passes to the thermoactuator 42 of the downstream thermostat 40. It is arranged at a position to bypass without causing a collision.

  To make such an arrangement, first, when the upstream thermostat 30 is manufactured, the center position in the winding direction in the planar processing portion 34a of the lower end portion (first valve side end portion) of the cylindrical compression coil spring 34 is The position of the jiggle valve 314 is determined as a reference position and arranged at a predetermined angular position on the circumference.

  As a specific example, in FIGS. 9 and 13, when the upper surface of the ring plate 311 is viewed on the clock face, the position of the jiggle valve 314 is assumed to be the 12 o'clock position of the clock face. It arrange | positions so that the winding direction center position of the plane process part 34a may correspond. In this example, since the center position in the winding direction of the planar processing portion 34a is not shifted from the position where the jiggle valve 314 exists to one side in the circumferential direction, the shift angle is 0 degree.

  In this way, the center position in the winding direction of the winding region 34 b that floats from the first valve 33 in the cylindrical compression coil spring 34 is the center position in the winding direction in the planar processing portion 34 a of the cylindrical compression coil spring 34 (that is, the jiggle valve 314. Is located at a position shifted by a predetermined angle β in one circumferential direction (clockwise direction). Thus, in the upstream thermostat 30, the center position in the winding direction of the floating winding region 34b with respect to the position of the jiggle valve 314 can be specified.

  Next, when assembling such an upstream thermostat 30 into the upstream communication hole 214 of the partition portion 213, for example, as shown in FIG. 13, the jiggle valve 314 of the upstream thermostat 30 is connected to the two communication holes 214, 215. The virtual straight line 102 passing through each center is arranged at a position shifted by a predetermined angle θ in the other circumferential direction (counterclockwise direction) with the imaginary straight line 102 as a reference position.

  In this way, the center position 101 of the opening start region 100 of the first valve 33 (the center position in the winding direction of the winding region 34b floating from the first valve 33 in the cylindrical compression coil spring 34) is the virtual straight line 102. On the other hand, they are arranged shifted by a predetermined angle α in one circumferential direction (clockwise direction).

  Thus, in the state where the upstream thermostat 30 is assembled to the upstream communication hole 214 of the partition part 213, the position where the jiggle valve 314 exists in the upstream thermostat 30 and the opening start region of the upstream communication hole 214 by the first valve 33 are obtained. The relative position with respect to the center position 101 of 100 is specified. Moreover, the direction of the imaginary straight line 105 (arrow 104 in FIG. 13) that starts to open from the center of the upstream communication hole 214 and passes through the center position 101 of the region 100 deviates without facing the thermoactuator 42 of the downstream thermostat 40. become.

  When such a configuration is adopted, when the first valves 33 and 43 of the two thermostats 30 and 40 start to open the center holes of the ring plates 311 and 411 and the communication holes 214 and 215 of the partition part 213, respectively. At the same time, when each of the second valves 35 and 45 starts to close the second inlet 223, the relatively low-temperature refrigerant remaining in the heat exchange path 4 and the radiator 3 flows into the lower chamber 23 from the first inlet 212. Then, the air begins to flow into the upper chamber 24 through the two communication holes 214 and 215. At this time, an opening formed by the opening start region 100 of the upstream thermostat 30 and the upstream communication hole 214 of the partition portion 213 is formed. Most of the relatively low-temperature refrigerant flowing into the upper chamber 24 through the thermoactuator 4 of the downstream thermostat 40 is indicated by a solid arrow 106 in FIG. To flow to bypass without direct collision to. Note that, as the angle α from the virtual straight line 102 to the center position 101 of the region 100 where the upstream communication hole 214 begins to open is reduced, the relatively low temperature refrigerant is less likely to collide with the thermoactuator 42 of the downstream thermostat 40.

  As a result, the thermowax 425 of the thermoactuator 42 of the downstream thermostat 40 is kept melted and expanded without being solidified and contracted, so that the first valves 33 and 43 of the two thermostats 30 and 40 both start to open. In this state, both the second valves 35 and 45 are maintained in a state where both have started to close. As described above, since the opening and closing operations of the two thermostats 30 and 40 can be synchronized, the occurrence of the phenomenon that the first valve 43 of the downstream thermostat 40 repeatedly opens and closes as described above can be avoided. . That is, when the first valves 33 of the two thermostats 30 and 40 start to open, it is possible to quickly synchronize them and shift to the fully opened state, so that the first inlet 212 → the lower chamber 23 → It becomes possible to quickly maximize the amount of refrigerant flowing from the upper chamber 24 to the outlet 222.

  As described above, in the embodiment to which the present invention is applied, the following effects can be obtained. First, since the two thermostats 30 and 40 are used without using a single thermostat, the two thermostats 30 and 40 have a relatively small maximum opening area compared to the case of using a single thermostat. In addition, the housing 20 can be downsized and the installation space can be reduced. Moreover, since the two thermostats 30 and 40 have the same specifications, it is possible to suppress the increase in the manufacturing cost of the cooling device, such as being able to purchase at a relatively low cost by mass purchase at the production site. .

  Further, as described above, the opening and closing operations of the two thermostats 30 and 40 can be synchronized relatively easily not by electronic control but by the temperature of the refrigerant. When the valves 33 and 43 start to open, it is possible to avoid the phenomenon that the first valve 43 of the downstream side thermostat 40 repeatedly opens and closes, and the first valve 43 of the downstream side thermostat 40 is quickly and completely opened. It becomes possible to shift to the open state.

  As described above, when the first valves 33 of the two thermostats 30 and 40 start to open, it is possible to quickly synchronize them and shift them to the fully opened state, so that the first inlet 212 → It becomes possible to quickly maximize the amount of refrigerant flowing from the lower chamber 23 → the upper chamber 24 → the outlet 222, and a large amount of refrigerant can be stably distributed to the radiator 3. As a result, it is possible to quickly and stably transition from the temperature increase promotion control state in which the temperature of the refrigerant is raised to the specified temperature to the temperature adjustment control state in which the refrigerant is maintained at the specified temperature. It is possible to prevent this phenomenon.

  Further, in this embodiment, when assembling the upstream thermostat 30 into the upstream communication hole 214 of the partition portion 213 of the housing 20, the center position 101 of the opening start region 100 by the first valve 33 of the upstream thermostat 30 is positioned. In this embodiment, since the existing position of the existing jiggle valve 314 installed on the ring plate 311 of the frame 31 of the upstream thermostat 30 is used as the reference position, there is no need to provide a special alignment mark or positioning structure. This is advantageous in suppressing an increase in equipment costs.

  Note that the present invention is not limited to the above-described embodiment, and each component of the cooling device can be appropriately changed within the scope of the claims of the present invention and a range equivalent to the scope. is there.

1 engine
2 Water pump
3 Radiators
4 Heat exchange path
5 Return route
6 Bypass
10 Channel switching part
20 Housing of flow path switching unit
21 Lower housing 212 First inlet 213 Partition 214 Upstream communication hole 215 Downstream communication hole
22 Upper housing 222 Outlet 223 Second inlet
23 Lower room
24 Upper room
30 upstream thermostat
40 Downstream thermostat 31, 41 Frame 311, 411 Ring plate 314, 414 Jiggle valve 32, 42 Thermo actuator 33, 43 First valve 34, 44 Cylindrical compression coil spring 34 a, 44 a Planar machining portion 34 b, 44 b Floating winding region 35, 45 Second valve 100 opening start area 101 center position of opening start area 102 Virtual straight line passing through the centers of the two communication holes

Claims (3)

A flow path switching unit for switching between a temperature adjustment control state in which the refrigerant taken out from the engine is circulated to the radiator and then returned to the engine, and a temperature increase promotion control state in which the refrigerant taken out from the engine bypasses the radiator and returns to the engine With
The flow path switching unit includes a housing having a room partitioned vertically in the vertical direction, and two thermostats incorporated in two communication holes provided in series in the refrigerant flow direction in the partition part of the two rooms. And the lower chamber is provided with a first inlet through which the refrigerant taken from the engine and passed through the radiator is introduced, and the upper chamber is introduced with the refrigerant taken out from the engine and bypassing the radiator A second inlet and an outlet for returning the refrigerant to the engine,
The two thermostat includes a frame central hole matching the communicating hole of the partition portion is provided, a first valve provided to allow opening and closing the central hole matching the prior Killen hole in the frame, the first 1 and a compression coil spring for urging the first valve so as to close the central hole matching the prior Killen holes in the valve, a second valve provided to allow opening and closing the second inlet, the upper the same time closing a center hole in which the temperature of the refrigerant of the are supported on the frame and in the upper room matches before Killen hole in the first valve when less than the predetermined temperature so as to be arranged in the room second while ensuring the temperature increase promotion control state by opening the second inlet in the valve, meets before Killen hole in the first valve when the temperature of the refrigerant in the upper room above the specified temperature Opening a Kokoroana by closing the second inlet at the same time the second valve and a thermo-actuator to secure the temperature control condition,
The thermostat on the upstream side in the refrigerant flow direction is arranged such that the center position of the first valve opening region is at a predetermined angular position on the circumference with respect to a virtual straight line passing through the centers of the two communication holes in the partition portion. An engine cooling system characterized by that. The engine cooling device according to claim 1,
Each frame of the two thermostats has a ring plate having the center hole, and a jiggle valve is provided at a predetermined circumferential position of each ring plate,
The first valve side end of the compression coil spring of the upstream thermostat is disposed at an arbitrary position in the circumferential direction with the position where the jiggle valve is present as a reference position, and the center position of the opening start region of the first valve Is specified with the presence position of the jiggle valve as a reference position. The engine cooling device according to claim 1 or 2,
2. The engine cooling apparatus according to claim 1, wherein the two thermostats have the same specifications.

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