JP6754705B2 - Internal combustion engine - Google Patents

Description

The present invention relates to a two-system cooling type internal combustion engine.

In an internal combustion engine, the cylinder block and the cylinder head are cooled by cooling water, and the cooling water often flows to the water jacket of the cylinder head after passing through the water jacket formed on the cylinder block. In the one-system system, when starting in a low temperature environment, the cooling water that has passed through the cylinder head and has been heated is cooled by the cylinder block, which causes a problem that the warm-up time becomes long. Since cooling water is used as a heat source, there is a problem that the heater is not effective during warm-up operation.

Therefore, when the engine temperature is below a certain level, the cooling water is not flowed through the cylinder block but only through the cylinder head, and when the engine temperature rises to a certain level, the cooling water is flowed through both the cylinder block and the cylinder head. A system cooling method has been proposed and implemented. As an example of this two-system cooling system, the applicant of the present application has disclosed Patent Document 1.

In the two-system cooling system, based on the engine temperature (or cooling water temperature), the flow of cooling water goes through the water jacket (block jacket) of the cylinder block and then toward the cylinder head, and via the cylinder block. It is switched to the state where it goes to the cylinder head without going through the cylinder head, and in Patent Document 1, the cooling water goes to the block going to the cylinder block and the cooling water goes to the cylinder head without going through the cylinder block. A water supply port for the head is provided on the outside of the block jacket and on the exhaust side.

Japanese Unexamined Patent Publication No. 2015-190450

The configuration of Patent Document 1 is excellent in the cooling water diversion function and has greatly evolved as compared with the prior art, but as a result of examination by the inventors of the present application, room for improvement was found. For example, since the water supply port for the block and the water supply port for the head are formed close to each other, it is necessary to secure a space in the cylinder block and the cylinder head for providing the water supply port for the head near the water supply port for the block. Therefore, there is a possibility that the cylinder block and the cylinder head become large.

Further, in the cylinder head, the temperature on the exhaust side is higher than that on the intake side, and if the cooling water comes into contact with the exhaust side first, thermal strain may occur in the cylinder head due to a sudden temperature drop. In the cylinder head, the cooling water flows from the intake side to the exhaust side to smooth the temperature gradient of the cooling water, but if a water supply port for the head is provided on the exhaust side, the cooling liquid is guided to the intake side in the cylinder head. A passage is required, which may complicate the structure of the cylinder head.

The present invention has been made in the wake of such a situation, and is intended to provide a more improved two-system cooling system.

The internal combustion engine of the present invention is
" A cylinder block formed by arranging a plurality of cylinder bores in the direction of the crank axis is formed so that a coolant jacket surrounding the group of cylinder bores opens upward.
A leak passage that flows toward the cylinder head when the coolant is lower than a preset predetermined temperature is circularly formed at one end of the coolant jacket located on the front end side or the rear end side facing the cylinder bore alignment direction. The portion of the coolant jacket excluding the leak passage is formed in an arc shape to form a main passage through which the coolant flows when the temperature is higher than a preset predetermined temperature.
The leak passage and the main passage are formed with cooling water inlets communicating with the coolant inflow passage provided in the cylinder block adjacent to each other.
The coolant flowing through the coolant inflow passage is switched between a state in which it mainly flows in the leak passage and a state in which it mainly flows in the main passage by a thermo valve whose valve body moves in response to the temperature of the coolant. "
It is a basic configuration.

Then, in claim 1, in the above basic configuration,
"The thermo valve has a form in which a sliding valve body and a temperature sensitive portion that slides the sliding valve body are coaxially arranged, and are arranged in the coolant inflow passage in a long posture in a direction crossing the coolant inflow passage. On the other hand
A temperature-sensitive space in which the temperature-sensitive portion of the thermo valve enters is formed in the cylinder block in a state of being branched from the coolant inflow passage. "
The configuration is added.

The invention of claim 2 has the above-mentioned basic configuration.
"A partition wall member having side plates overlapping or spaced apart from the inner surface of the coolant jacket is arranged in the leak passage, and is located on the side plate of the partition wall member on the side of the coolant inflow passage. On the other hand, an inlet-side partition wall forming a boundary between the cooling water inlet of the leak passage and the cooling water inlet of the main passage is formed at the end of the leak passage.
The thermo valve has a form in which a sliding valve body and a temperature sensitive portion that slides the sliding valve body are coaxially arranged.
A valve hole is formed in the inlet side partition wall provided on the side plate of the partition wall member to switch the flow of cooling water by fitting and removing the valve body of the thermo valve, and the thermo valve is placed on the side plate of the partition wall member. A support for holding is formed ,
In addition, a temperature-sensitive space in which the temperature-sensitive portion of the thermo valve is exposed is formed at the inlet side partition wall so as to communicate with the coolant inflow passage. "
The configuration is added.

In the configuration of claim 1 , since the coolant outlet toward the cylinder head can be formed at the end of the leak passage opposite to the cooling water inlet, the coolant inlet and the coolant outlet of the leak passage do not interfere with each other. kill in the formation. Therefore, the freedom of design is high, and it is possible to contribute to the compactification of the cylinder block and the cylinder head.

Further, when the engine temperature is low, a part of the coolant jacket surrounding the cylinder bore group is used to direct the coolant to the cylinder head, and a part of the coolant jacket is used for the two-system cooling system. Since it is also used as a leak passage, the structure can be simplified accordingly.

In the configuration of claim 2, since the flow of the coolant can be switched inside the coolant jacket, it is possible to further contribute to the compactness (prevention of upsizing) of the cylinder block.

When the cooling water inlet of the leak passage is provided on the exhaust side and the cooling water outlet of the leak passage is provided on the intake side as in the embodiment, the cooling liquid flows into the cylinder head from the intake side, so that the inside of the cylinder head The structure of the jacket can be simplified. As a result, it can contribute to cost reduction and improvement of cooling performance by smoothing the flow of coolant.

When the coolant inlet of the leak passage is disposed on the exhaust side, the coolant pump (water pump), the front portion of the cylinder block but will be provided on the exhaust side of the (front front portion of the cover is exactly) If the coolant pump is installed on the exhaust side, the intake side can be opened, so it is possible to place a heat-sensitive alternator, ISG (Integrated Starter Generator), or air conditioner compressor on the intake side. The freedom of placement of heat-sensitive auxiliary equipment can also be improved.

As the valve device, there are an electromagnetic solenoid type and an electric motor type , but when a thermo valve is used as in the present invention , the flow of the coolant is made sensitive to the coolant temperature without requiring a special control device. You can switch accurately. Therefore, it is advantageous in terms of cost and also excellent in reliability.

When the leak passage and the main passage are separated by using the partition wall member as in claim 2, the basic structure of the coolant jacket may be the same as the conventional one, so that the labor required for manufacturing and processing the cylinder block can be reduced. Furthermore, since the attaching the thermo valve in the partition member, it is possible to switch the flow of the cooling liquid by the thermo valve accurately, further, can be loaded in the cylinder block in a state of a unit incorporating a thermo-valve in the partition wall member Therefore, the labor of assembling can be reduced.

If the leak passage is exposed on the inner surface of the coolant jacket, the leak passage part of the cylinder block will be cooled by the coolant when the engine temperature is low, but the coolant will not move in the main passage. , The temperature of the coolant gradually rises. Therefore, in the cylinder block, a temperature difference may occur between the location of the leak passage and the main passage.

In this regard, if the side plate is provided on the partition wall member as in claim 2 , the side plate can exert a heat insulating effect and prevent the cylinder block from being supercooled at the leak passage. Therefore, it is possible to prevent thermal strain from being generated in the cylinder block due to the difference in temperature.

It is a top view of the cylinder block of 1st Embodiment. It is a partially cutaway plan view of a main part in a state where a coolant flows directly to a cylinder head. It is a partially cutaway plan view of a main part in a state where a coolant flows through a cylinder block. (A) is the IVA-IVA view of FIG. 1, (B) is the IVB-IVB view of FIG. 2, and (C) is the IVC-IVC view of FIG. It is a figure which shows the 2nd to 4th Embodiment which is the modification of 1st Embodiment. It is a figure which shows 5th and 6th Embodiment which is another example of the means of forming a leak passage. (A) is a perspective view of the seventh embodiment, and (B) is a partially broken plan view. 7 is a sectional view taken along line VIII-VIII of FIG. 7B. It is a perspective view of 8th Embodiment which is a modification of 7th Embodiment. In the figure which shows a reference example , (A) is a perspective view of a bulkhead member, (B) is a plan sectional view in a state where a valve device is incorporated. 9 is a view showing a ninth embodiment, in which (A) is a partially broken plan view, (B) is a sectional view taken along line BB of (A), and sectional views taken along line CC of (C) and (A). (D) is a plan sectional view in a state where the valve body is retracted. It is a figure which shows the tenth embodiment.

(1). Outline of First Embodiment Next, an embodiment of the present invention will be described with reference to the drawings. This embodiment is applied to an internal combustion engine for a vehicle. First, the first embodiment shown in FIGS. 1 to 4 will be described.

The internal combustion engine of the present embodiment has three cylinders, and therefore, the cylinder block 1 is formed with three cylinder bores 2 arranged in series in the crank axis direction. The center line passing through the axis of each cylinder bore 2 is indicated by the symbol O. In FIG. 1, the right side across the center line O is the exhaust side, and the left side across the center line O is the intake side. The lower side of the sheet has become the front in FIG. 1, a front cover 3 that covers the timing chain (see FIG. 4 (A)) has become heavy to front surface 1a of the cylinder block 1.

The cylinder block 1 is formed with a loop-shaped coolant jacket (block jacket) 4 that surrounds a group of cylinder bores 2. Further, on the exhaust side side surface of the cylinder block 1, a coolant inflow passage 5 for sending the coolant to the coolant jacket 4 is formed at a portion located next to the cylinder bore 2 located in the foreground. A pedestal 6 is formed on the exhaust side side surface of the cylinder block 1 where the coolant inflow passage 5 is open, and the water pump 7 is fixed to the pedestal 6. Needless to say, the water pump 7 is driven by an auxiliary drive belt.

A resin partition wall member 8 is attached to a portion of the coolant jacket 4 that surrounds the cylinder bore 2 located on the front side about half a circumference from the front. The partition member 8 has a plan-view arcuate side plate 9 that overlaps the inner surface of the coolant jacket 4, and partition walls 10 and 11 formed at both ends of the side plate 9, and the partition walls 10 and 11 form a coolant jacket. It divides 4.

Therefore, the coolant jacket 4 is separated into an arc-shaped leak passage 12 that surrounds the cylinder bore 2 on the front side by about half a circumference and a main passage 13 excluding the leak passage 12. Therefore, the leak passage 12 and the main passage 13 have a symmetrical shape with the center line O long in the arrangement direction of the cylinder bores 2 interposed therebetween, and the exhaust side end of the leak passage 12 and the exhaust side end of the main passage 13. The portions are adjacent to each other as cooling water inlets 12a and 13a communicating with the coolant inflow passage 5, and the intake side end of the leak passage 12 and the intake side end of the main passage 13 are cooling water outlets 12b and 13b. Are next to each other.

The leak passage 12 is a flow path that directly sends the coolant to the cylinder head 14 (see FIG. 4A) when the engine temperature is lower than a predetermined value, as in the warm-up operation, and is an engine. When the temperature is low, the coolant flows through the leak passage 12 from the cooling water inlet 12a toward the cooling water outlet 12b, and is sent from the cooling water outlet 12b to the cylinder head 14. Therefore , the cooling water inlet 12a and the cooling water outlet 12b of the leak passage 12 are distributed and arranged on both sides of the cylinder bore row center line O.

Not shown figure, the cylinder head 14, first inflow hole (not shown) which communicates with the cooling water outlet 12b of the leak passage 12 is vacant. In FIG. 2, the portion corresponding to the first inflow hole of the cylinder head 14 (the portion of the coolant outlet 12b ) is shaded.

When the engine temperature (coolant temperature) exceeds a preset value, most of the coolant flows into the cooling water inlet 13a of the main passage 13 and is sent to the cylinder head 14 from the cooling water outlet 13b of the main passage 13. .. Therefore, the cylinder head 14 has a second inflow hole (not shown) communicating with the cooling water outlet 13b of the main passage 13. In FIG. 3, a portion (cooling water outlet 13b) corresponding to the second inflow hole is shaded. Reference numerals 15 shown in FIGS. 1 to 3 are tap holes into which head bolts are screwed.

(2). Switching the flow of the coolant As shown in FIGS. 2 and 3, in the cylinder block 1, the coolant inflow passage 5 is provided with the coolant in the leak passage 12 and the main passage 13 according to the temperature. A thermo valve 17 is provided to switch to and flow.

The thermo-valve 17 has a central shaft 18 parallel to the crank axis direction, a temperature sensing portion 19 fixed to the central shaft 18 so as not to move, and a valve body 20 that fits into the central shaft 18 and slides to cool the thermo valve 17. The liquid inflow passage 5 is arranged in a long posture in a direction crossing the passage 5. The temperature sensing portion 19 of the thermo-valve 17 has a built-in wax volume by temperature changes, the slide tube 21 to slide by the temperature change of the wax is fitted on the central shaft 18. The valve body 20 is fixed to the slide cylinder 21.

Therefore, the valve body 20 slides due to the temperature change of the coolant. In the present embodiment, the valve body 20 moves forward when the temperature of the coolant is low, and moves backward when the temperature rises. To be precise, the valve body 20 starts to retreat when the coolant reaches a predetermined first temperature, and completely retreats when it reaches a predetermined second temperature. Therefore, when the temperature of the coolant is lower than the first temperature, the valve body 20 is fully advanced, and when the temperature of the coolant is lower than the second temperature, the valve body 20 is completely retracted to the first temperature. in the region between the second temperature, the valve body 20 is located between a retracted position and before proceeding position, coolant flows to both the leak passage 12 and the main passage 13.

As shown in FIGS. 2 and 3, the coolant inflow passage 5 is connected to the first passage 5a communicating with the cooling water inlet 12a of the leak passage 12 in the coolant jacket 4 and the cooling water inlet 13a of the main passage 13 in the coolant jacket 4. It has a second passage 5b that communicates with each other, and both passages 5a and 5b are separated by a wall 22. The wall 22 is located at the exhaust side partition wall 10 of the partition member 8.

Then, the valve body 20 of the thermo valve 17 penetrates through the hole 23 made in the wall 22. As shown in FIGS. 4B and 4C, the valve body 20 is slidably inserted into the round hole 24 formed in the cylinder block 1, and the passages 5a and 5b are in a posture crossed with the round hole 24. .. The cylinder block 1 is formed with a temperature sensing space 25 in which the temperature sensing portion 19 of the thermo valve 17 is exposed. The temperature-sensitive space 25 has a form branched from the coolant inflow passage 5 in the crank axis direction, and the cooling liquid comes into overall contact with the coolant in the temperature-sensitive space 25, so that the wax of the temperature-sensitive portion 19 is used. The volume changes in response to the temperature of the coolant.

As described above, when the temperature of the coolant (engine temperature) is lower than the first temperature, the valve body 20 is advanced, the first passage 5a of the coolant inflow passage 5 is opened, and the second passage 5b is closed. ing. Therefore, the entire coolant flows to the cylinder head 14 via the leak passage 12. In this state, the coolant does not flow in the main passage 13 and remains accumulated. Therefore, the temperature is gradually raised.

When the temperature of the coolant reaches the first temperature, the valve body 20 begins to recede. Therefore, the coolant flows into both the leak passage 12 and the main passage 13. The ratio is proportional to the temperature. When the temperature of the coolant rises to a predetermined second temperature, the valve body 20 is completely retracted, the first passage 5a of the coolant inflow passage 5 is fully closed, and the second passage 5b is fully opened. Therefore, almost all of the coolant flows into the main passage 13. In order to cool the cylinder block 1 evenly, it is preferable to set so that even if the valve body 20 of the thermo valve 17 is fully retracted, some of both coolants flow into the leak passage 12.

When the partition wall member 8 is provided with the side plate 9 overlapping the inner surface of the coolant jacket 4 (leak passage 12) as in the present embodiment, the side plate 9 acts as a heat insulating material, so that the coolant only covers the leak passage 12. It is possible to prevent the cylinder block 1 from being overcooled at the location of the leak passage 12 in the flowing state.

Thermo-valves have been conventionally used as a means for controlling the flow of coolant (cooling water), including internal combustion engines for vehicles. The thermo valve operates accurately and is highly reliable. Even this embodiment, by using the thermo-valve 17 as a BenSo location, perform the water flow control the leak passage 12 and the main passage 13 easily and accurately.

(3). Modification example (Figs. 5 to 6)
In the above description, the inflow hole of the cylinder head 14 is formed directly above the coolant jacket 4, but as shown in FIG. 5 as the second embodiment, the coolant outlet communicating with the inflow hole of the cylinder head 14 is formed. 26, 27 may be formed on the outside of the coolant jacket 4 (12, 13). In this case, the coolant outlets 26, 27 and the coolant jackets 4 (12, 13) are communicated with each other by the grooves 28, 29 formed in the cylinder head 14.

Further, the cylinder head 14 may have only one inflow hole. In this case, as shown in FIG. 5 (B) as the third embodiment, one coolant outlet 30 located outside the coolant jacket 4 may be formed in the cylinder block 1 or FIG. 5 (C). ) As a fourth embodiment, the connecting portion between the leak passage 12 and the leak passage 12 on the intake side is formed as a common coolant outlet 31, and water is supplied from the coolant outlet 31 to the cylinder head 14. May be good.

As can be understood from FIGS. 5B and 5C, it is not always necessary to partition the leak passage 12 and the leak passage 12 on the intake side (outlet side) . That is, in the state where the coolant is flowing in the leak passage 12, the coolant does not flow back in the main passage 13, so that the leak passage 12 and the main passage 13 are not separated by the intake side, but in the main passage 13 . There is almost no flow of coolant, and a two-system cooling system can be realized.

In the first embodiment, the side plate 9 of the partition member 8 extends over the entire length of the leak passage 12, but as shown in FIG. 6A as the fifth embodiment, only at the end of the leak passage 12. It is also possible to provide the partition member 8. Further, as shown in FIG. 6B as the sixth embodiment, it is also possible to provide the partition wall member 8 with a side plate 32 that overlaps the outer surface of the leak passage 12. Although not shown, inner and outer side plates 9 and 32 may be provided.

(4). 7th to 8th embodiments (FIGS. 7 to 9)
7 and 8 show a seventh embodiment, which is a specific example of claim 2. In the seventh embodiment, the thermo valve 17 is arranged in a vertical posture (a posture parallel to the cylinder bore 2), and the valve body 20 is vertically movable. Further, the partition wall member 8 is provided with the horizontal partition wall 33, and the portion above the horizontal partition wall 33 is formed in the leak passage 12. The lower end of the side plate 9 stops at the horizontal partition wall 33, but as shown by the alternate long and short dash line, it can be extended to the bottom of the leak passage 12.

In the present embodiment, the coolant inflow passage 5 is provided at a height halfway up and down at the exhaust side end of the leak passage 12. Therefore, at the exhaust side end of the leak passage 12, a horizontal auxiliary horizontal partition wall 36 located below the horizontal partition wall 33 and a first and second auxiliary horizontal partition wall 36 separated in the circumferential direction with the auxiliary horizontal partition wall 36 interposed therebetween. Vertical partition walls 37 and 38 are provided to form a distribution space 39 communicating with the coolant inflow passage 5.

The first vertically long partition wall 37 forming the outside of the leak passage 12 extends from the auxiliary horizontal partition wall 36 to the upper end of the partition wall member 8, and the second vertically long partition wall 38 located inside extends from the horizontal partition wall 33 to the partition wall. It extends to the lower end of the member 8. Therefore, the leak passage 12 and the main passage 13 are separated by a stepped wall. In this embodiment, the entrance side partition wall according to claim 2 is formed by a group of the exhaust side end portion 33a of the horizontal partition wall 33, the auxiliary horizontal partition wall 36, and the first and second vertically elongated partition walls 37 and 38. Is configured.

The horizontal and the exhaust side end portion 33a and the auxiliary horizontal partition wall 36 of the partition wall 33, and open upper and lower valve hole 40 and 41 in a concentric state, as shown in Figure 8, the valve body 20 is in the vertical By selectively closing the valve holes 40 and 41, the coolant selectively flows into the leak passage 12 and the main passage 13. That is, in a state in which closes the upper vent hole 41 in the valve body 20, the cooling liquid flows in the leak path 12 through the upper valve hole 40, in a state that closes the upper vent hole 40 in the valve body 20, the cooling fluid Flows into the main passage 13 through the lower valve hole 41. It is the same as before toward the cylinder head 14 after flowing through the coolant jacket 4.

In this embodiment, the inner surface of the rie click passage 12 because it is covered by the side plate 9, can be prevented accurately the cylinder block 1 at a point leak passage 12 is excessively cooled.

The thermo valve 17 is basically the same as in the first embodiment , and the valve body 20 is attached to the slide shaft 42 provided in the temperature sensing portion 19. The temperature sensitive portion 19 is fixed to the support portion 8c formed on the partition wall member 8. Therefore, the partition member 8 and the valve device 17 are unitized into one. Therefore, by fitting the partition wall member 8 into the coolant jacket 4 from above, the valve device 17 is set, and the leak passage 12 and the main passage 13 are formed.

In the embodiments shown in FIGS. 7 and 8, the second vertically elongated partition wall 38 was extended to the bottom surface of the coolant jacket 4, but as shown in FIG. 9 as the eighth embodiment, the second vertically elongated partition wall 38 and the coolant jacket A certain distance of dimension E may be provided between the bottom surface of 4 and the bottom surface of 4. With this configuration, the lower portion of the leak passage 12 becomes the front portion 13'of the main passage 13, and the coolant flows around the entire circumference of the coolant jacket 4 in a state where the engine temperature is high. Therefore, it is suitable for uniform cooling of the cylinder block 1.

(5). Reference example (Fig. 10)
In the reference example shown in FIG. 10, similarly to the seventh embodiment, the leak passage 12 is divided into upper and lower parts by the horizontal partition wall 33, and the auxiliary horizontal partition wall 36 and the first and second vertically elongated partition walls 37 and 38 are separated. It is provided to form a distribution space 39 that communicates with the coolant inflow passage 5. Further, in this embodiment, a third vertically elongated partition wall 43 connected to the lower surface of the horizontal partition wall 33 is formed inside the distribution space 39, and the auxiliary horizontal partition wall 36 is extended to the third vertically elongated partition wall 43. Therefore, the auxiliary distribution space 44 is formed.

Then, concentric valve holes 45 and 46 are formed in the first vertically elongated partition wall 37 and the second vertically elongated partition wall 38, and the two valve holes 45 and 46 are selectively opened and closed by the horizontally moving valve body 20. It has become like. A relief hole 47 communicating with the auxiliary distribution space 44 is formed in the exhaust side end 33a of the horizontal partition wall 33. The valve device 17 'is, for example, an electromagnetic solenoid type, the body 48 is fixed to the outer surface of the third longitudinal partition wall 43, that secure the valve element 20 to the rod 49.

In this reference example , the lower portion of the leak passage 12 is formed as the front portion 13'of the main passage 13 by forming a notch 37a at the lower end of the first vertically long partition wall 37. Therefore, the main passage 13 is formed over the entire circumference of the coolant jacket 4.

(5). 9th and 10th embodiments (FIGS. 11 to 12 )
Also in the ninth embodiment shown in FIG. 11, the semicircular partition member 8 is arranged at the front end portion of the coolant jacket 4, but in this embodiment, the side plate 9 is placed halfway in the groove width direction of the coolant jacket 4. By arranging in the portion, the leak passage 12 and the front portion 13'of the main passage 13 are formed at the front end portion of the coolant jacket 4. Therefore, in the present embodiment, the leak passage 12 and the front portion 13'of the main passage 13 are formed separately in the groove width direction of the coolant jacket 4.

The leak passage 12 is located outside the coolant jacket 4 in the radial direction, and the front portion 13'of the main passage 13 is located inside the radial direction . As shown in ( B), the partition wall member 8 includes a bottom plate 50, and the side plate 9 rises from the bottom plate 50. Therefore, only Komu fit the partition member 8 to the coolant jacket 4, the side plate 9 is self-supporting. In order to further improve the posture stability, the side plate 9 may be provided with an auxiliary strut piece that abuts on the inner and outer surfaces of the coolant jacket 4.

A partition wall 10 for partitioning the leak passage 12 and the main passage 13 in the circumferential direction is provided at the end of the partition wall member 8 near the coolant inflow passage 5, and the partition wall 10 is provided with a valve of the thermo valve 17. A valve hole 45 opened and closed by the body 20 is opened. Thermo valve 17 is arranged in a horizontal shape includes a rod 48 the valve body 45 is fixed, it is fixed to a pair of support portions (support plate) 51 formed in the partition wall member 8. The support portion 51 rises integrally from the overhanging portion 50a of the bottom plate 50. Therefore, also in this embodiment, the thermo valve 17 and the partition member 8 are unitized. The space between the pair of support portions 51 is a temperature sensing space 25 in which the temperature sensing portion 19 of the thermo valve 19 is exposed.

In this embodiment, the coolant inflow passage 5 and the leak passage 12 are always in communication with each other. Therefore, as in (A), in the state where the communication hole 45 is closed by the valve body 20, the coolant flows only in the leak passage, and in the state where the valve body 20 retracts and the communication hole 45 is opened, The coolant flows into both the main passage 13 and the leak passage 12. Since the leak passage 12 is not exposed on the inner surface of the coolant jacket 4, the cylinder block 1 is not supercooled by the coolant when the engine temperature is low.

Further, since the front 13 'the groove width of the main passage 13 is small, most of the coolant was not toward the main passage 13 flows so as to surround the outer group of cylinder bores 2. Therefore, the cylinder block 1 can be uniformly cooled over the entire circumference of the coolant jacket 4.

FIG. 12 shows a tenth embodiment which is a modification of the embodiment of FIG. In this embodiment, the first vertically elongated partition wall 52 located at the outer end of the side plate 9 and the second vertically elongated partition wall 53 located inside the outer end of the side plate 9 are parallel to the exhaust side end of the partition wall member 8. The valve holes 54 and 55 formed in the vertically elongated partition walls 52 and 53 are partitioned by the valve body 20 of the valve device 17 to select enemies by forming a cooling liquid distribution space 39 between the two. I am doing it.

The thermo-valve 17 has the same shape as before and is arranged horizontally, and the temperature-sensitive portion 19 is attached to a pair of support portions 51 formed on the partition wall member 8. In this case, the support portion 51 is extended to the upper end of the coolant jacket 4, both support portions 51 are connected by an inner partition wall 56 on the side of the leak passage 12, and one support portion 51 and the second vertically long partition wall 53 are connected to each other. Are connected by an outer partition wall 57. Therefore, the coolant in the coolant inflow passage 5 flows into the leak passage 12 only from the valve hole 55 of the second vertically long partition wall 53.

Therefore, in this embodiment, by selectively closing the two communication holes 54 and 55 with the valve body 20, the coolant is switched between a state in which it flows only in the leak passage 12 and a state in which it flows only in the main passage 13. Similar to the ninth embodiment, since the main passage 13 extends over the entire circumference of the coolant jacket 4, the cylinder block 1 can be cooled evenly. The temperature sensing portion 19 of the thermo valve 17 is exposed in the temperature sensing space 25 communicating with the coolant inflow passage 5.

When a part of the coolant jacket 4 is partitioned in the groove width direction to form the leak passage 12 as in the ninth and tenth embodiments, the portion (front portion) of the coolant jacket 4 that forms the leak passage 12 It is also possible to make the groove width larger than other parts.

Although an embodiment has been described what example of the present invention, the present invention, Ru can be variously embodied to other.

The invention of the present application can be actually embodied in an internal combustion engine. Therefore, it can be used industrially.

1 Cylinder block 2 Cylinder bore 4 Coolant jacket (block jacket)
5 Coolant inflow passage 7 Water pump 8 Partition member 9 Side plate 10, 11 Partition wall 12 Leak passage 12a Leak passage coolant inlet 12b Leak passage coolant outlet 13 Main passage
13a Main passage cooling water inlet 13b Main passage cooling water outlet 17 Thermo valve 18 Central axis 19 Temperature sensitive part 20 Valve body 21 Slide cylinder 33 Horizontal partition wall
36 Auxiliary horizontal partition walls that make up the entrance side partition wall 37, 38 , 52 Vertical partition walls that make up the entrance side partition wall 39 Space for distribution

Claims (2)

A cylinder block formed by arranging a plurality of cylinder bores in the direction of the crank axis is formed so that a coolant jacket surrounding the group of cylinder bores opens upward.
A leak passage that flows toward the cylinder head when the coolant is lower than a preset predetermined temperature is circularly formed at one end of the coolant jacket located on the front end side or the rear end side facing the cylinder bore alignment direction. The portion of the coolant jacket excluding the leak passage is formed in an arc shape to form a main passage through which the coolant flows when the temperature is higher than a preset predetermined temperature.
The leak passage and the main passage are formed with cooling water inlets communicating with the coolant inflow passage provided in the cylinder block adjacent to each other.
The coolant flowing through the coolant inflow passage is switched between a state in which it mainly flows in the leak passage and a state in which it mainly flows in the main passage by a thermo valve whose valve body moves in response to the temperature of the coolant. It ’s a composition,
The thermo valve has a form in which a sliding valve body and a temperature sensitive portion that slides the sliding valve body are coaxially arranged, and is arranged in the coolant inflow passage in a long posture in a direction crossing the coolant inflow passage. On the other hand
A temperature-sensitive space in which the temperature-sensitive portion of the thermo valve enters is formed in the cylinder block in a state of being branched from the coolant inflow passage.
Internal combustion engine. A cylinder block formed by arranging a plurality of cylinder bores in the direction of the crank axis is formed so that a coolant jacket surrounding the group of cylinder bores opens upward.
A leak passage that flows toward the cylinder head when the coolant is lower than a preset predetermined temperature is circularly formed at one end of the coolant jacket located on the front end side or the rear end side facing the cylinder bore alignment direction. The portion of the coolant jacket excluding the leak passage is formed in an arc shape to form a main passage through which the coolant flows when the temperature is higher than a preset predetermined temperature.
The leak passage and the main passage are formed with cooling water inlets communicating with the coolant inflow passage provided in the cylinder block adjacent to each other.
The coolant flowing through the coolant inflow passage is switched between a state in which it mainly flows in the leak passage and a state in which it mainly flows in the main passage by a thermo valve whose valve body moves in response to the temperature of the coolant. It ’s a composition,
A partition wall member having side plates overlapping or spaced apart from the inner surface of the coolant jacket is arranged in the leak passage, and is located on the side plate of the partition wall member on the side of the coolant inflow passage. At the end, an inlet-side partition wall forming a boundary between the cooling water inlet of the leak passage and the cooling water inlet of the main passage is formed.
The thermo valve has a form in which a sliding valve body and a temperature sensitive portion that slides the sliding valve body are coaxially arranged.
A valve hole is formed in the inlet side partition wall provided on the side plate of the partition wall member to switch the flow of cooling water by fitting and removing the valve body of the thermo valve, and the thermo valve is placed on the side plate of the partition wall member. A support for holding is formed ,
In addition, a temperature-sensitive space in which the temperature-sensitive portion of the thermo valve is exposed is formed at the inlet side partition wall so as to communicate with the coolant inflow passage.
Internal combustion engine.

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