JP6284379B2 - Internal combustion engine - Google Patents

Description

The present invention relates to an internal combustion engine including a pump unit such as a water pump.

  The water pump of the internal combustion engine is driven by an accessory drive belt, and the accessory drive belt is wound around a crank pulley fixed to one end of the crankshaft. Therefore, one end of the crankshaft is exposed from one end surface of the cylinder block.

  The structure of the water pump varies, but in any case, the rotating shaft to which the blade (impeller) is fixed is parallel to the crankshaft, and a pulley is fixed to one end of the rotating shaft. Therefore, the water pump is disposed near the accessory drive belt.

There are various structures and arrangements of the water pump. For example, Patent Document 1 discloses that a water pump is fixed to an end of one side surface of a cylinder block parallel to the crankshaft, and a pulley is arranged outside one end surface of the cylinder block. to thereby protruding, it is wrapped around the accessory drive belt disclosed therein.

  In this patent document 1, the inflow pipe for returning water to the water pump is in a posture parallel to the crankshaft, and the inflow pipe is connected to the water pump from the other end face side of the cylinder block opposite to the accessory drive belt. It extends toward. The discharge passage faces the cylinder block and communicates with a main gallery provided in the cylinder block. Therefore, in Patent Document 1, the inflow passage and the discharge passage are in an orthogonal posture in a plan view.

  Now, the housing of the water pump is divided into a pump housing and a cover housing, and the two housings are overlapped and fastened with bolts. Patent Document 2 discloses that a pump housing having a pump chamber is provided integrally with a cylinder block. In Patent Document 2, the inflow passage and the discharge passage are parallel to each other. The water is flowing in a U-turn.

JP 2010-77883 A Japanese Patent Laid-Open No. 10-212950

  If a structure in which the housing is separated from the cylinder block and fastened to the cylinder block with a bolt as in Patent Document 1, the advantage that a general-purpose water pump such as a commercially available product can be used and the structure of the cylinder block are different. It has the advantage that it can contribute to cost reduction by using a common water pump in many models, or has the advantage that it can easily cope with design changes.

However, in the configuration in which the inflow passage and the discharge passage are just orthogonal as in Patent Document 1, the position of the pump chamber is restricted by the main gallery of the cylinder block, so that the position of the pulley is greatly increased from one end surface of the cylinder block. brings the away, the length of the rotary shaft is inevitably considerably longer, then, or large-sized as a whole water pump, a reduction in the degradation or discharge capacity of the durability twisting occurs in the rotation shaft There is a risk of

  On the other hand, if the inflow passage and the discharge passage are formed in parallel as in Patent Document 2, it can contribute to downsizing, but the structure is limited, so the versatility is low and the design change is troublesome. . Further, in Patent Document 2, since the inlet of the inflow passage and the discharge port of the discharge passage are at the same position, even if the water pump of Patent Document 2 is separated from the cylinder block, the entire pump unit is thick. There is a problem that there is a limit to downsizing.

  The present invention has been made to improve the current situation.

The present invention relates to an internal combustion engine,
“A cylinder block in which a crankshaft is rotatably held, a chain case fixed to one end surface of the cylinder block, and a pump unit disposed on one side surface of the outer peripheral surface of the cylinder block parallel to the crankshaft. With
The pump unit has a housing having a pump chamber therein, a pumping member disposed in said pump chamber, and a pulley or sprocket for rotating the pre-Symbol pumping member,
The housing is formed with an inflow passage for guiding fluid to the pump chamber and a discharge passage for pumping fluid from the pump chamber. The housing has a rotation axis of the pulley or sprocket parallel to the crankshaft. while in attitude are bolted to one side of the cylinder block,
The pulley or sprocket, by arranging the outer side than the chain case, Ru is a power transmission belt or chain from the crankshaft to the pulley or sprocket "
It has become the basic configuration called.

And in the above basic configuration,
Wherein the inflow passage and the discharge passage is a horizontal position and open on the opposite side of the pulley or sprocket, and the inflow passage with the discharge passage is positioned closer to the cylinder block is positioned farther from the cylinder block the way, the and overlap in a direction perpendicular to one side surface of the cylinder block, furthermore, the the tip of the discharge passage has a discharge port opened, the inlet of the inflow passage, than the discharge port Shifted to the pulley or sprocket side ,
Further, the housing has a protruding portion that overlaps the outer surface of the chain case when viewed from the crank axis direction, and the protruding portion is attached to the chain case by a bolt so that the protruding portion does not shift in a direction perpendicular to the crank axis line. Connected,

  When the discharge passage and the inflow passage overlap each other as in the present invention, the housing has a bulging structure when viewed from the direction of the rotation axis of the pulley, so the rigidity is improved and resistance to twisting and bending is improved. it can. As a result, it is possible to prevent the problem that the rotating shaft is twisted due to the bending of the housing and the durability is lowered or the discharge performance is lowered.

  In addition, since the inlet of the inflow passage is shifted to the pulley or sprocket side from the discharge port of the discharge passage, the length of the inflow pipe can be kept to the minimum necessary to make the pump unit as compact and lightweight as possible. it can.

In this case, if the pump chamber is configured to be located outside the one end face of the cylinder block as in the embodiment, the length of the rotating shaft is reduced as much as possible even if the position of the pulley is far away from the one end face of the cylinder block. And has an advantage of ensuring a smooth rotation.
Further, in the present invention, since the protruding portion of the housing is connected to the chain case, the housing is prevented from being displaced downward by the bolt, so that a downward force acts on the pulley or sprocket by the belt or the chain. Even so, the force does not act on the housing, and the housing is held in a stable state. As a result, it is possible to prevent problems such as liquid leakage due to displacement of the housing or twisting of the rotating shaft due to distortion in the housing.

1 is a schematic front view of an internal combustion engine according to an embodiment. FIG. 2 is a side view of the internal combustion engine, as viewed from II-II in FIG. 1. It is an enlarged side view of the principal part. FIG. 4A is a cross-sectional view taken along the line IV-IV in FIG. 3 in a state where the pulley is indicated by a virtual line, and FIG. 4B is a front view of the cover housing. (A) is a separated side view of a pump housing and a cover housing, (B) is a BB view sectional view (front view of a pump housing) of (A). Figure 3 is a VI-VI cross-sectional view of 及 beauty Figure 4 (A).

(1). Outline of Internal Combustion Engine Next, an embodiment of the present invention will be described based on the drawings. First, an outline of the internal combustion engine will be described. As shown in FIGS. 1 and 2, the internal combustion engine includes a cylinder block 1, a cylinder head 2 fixed to the upper surface of the cylinder block 1, a cylinder head cover 3 fixed to the upper surface of the cylinder head 2, and oil fixed to the lower surface of the cylinder block 1. A pan 4 is provided, and one chain case 6 is fixed by a plurality of bolts 7 to one end faces 1 a and 2 a of the cylinder block 1 and the cylinder head 2 facing the one end direction of the crankshaft 5.

  In the following, for convenience, front / rear / left / right language for specifying the direction will be used. The axial direction of the crankshaft 5 is the front / rear direction, and the horizontal direction perpendicular to the crankshaft 5 is the left / right direction. These are clearly shown in FIGS.

  Although not shown, there is a space between one end face 1a of the cylinder block 1 and the chain case 6, and a timing chain is disposed in this space. An oil filter 8 is provided at the lower end of the chain case 6.

One end of the crankshaft 5 protrudes to the outside of the chain case 6, and a crank pulley 9 is fixed to the protruding end. An auxiliary machine drive belt 10 is wound around the crank pulley 9, and a water pump 11 and an air conditioner compressor 12 are driven by the auxiliary machine drive belt 10. Accordingly, the water pump 11 and the air conditioner compressor 12 include pulleys 13 and 14, respectively. The auxiliary machine driving belt 10 can also drive other auxiliary machines such as an alternator. The water pump 11 is an example of a pump unit.

  The water pump 11 and the air conditioner compressor 12 are arranged close to one side 1 b of the cylinder block 1 on one side orthogonal to the crankshaft 5. That is, they are arranged close to the right side in FIG. 1, and the accessory drive belt 10 circulates clockwise in FIG. For this reason, a substantially downward load (pressing force) is applied to the pulley 13 of the water pump 11 by the driving of the accessory drive belt 10 as indicated by the white arrow.

  The internal combustion engine is a multi-cylinder system such as a three-cylinder engine, for example, but a collecting passage communicating with each exhaust port is formed inside the cylinder head 2, and an exhaust outlet hole 16 communicating with the collecting passage is formed as shown in FIG. The cylinder head 2 is open on one side 2b. A joint pipe 17 communicating with the exhaust outlet hole 16 is fixed to one side surface 2 b of the cylinder head 2, and a catalyst case 18 having a catalyst disposed therein is connected to the joint pipe 17.

  The upper part 18a and the lower part 18b of the catalyst case 18 are each tapered, and a sleeve 19 is fixed to the lower end. An exhaust pipe (not shown) is connected to the sleeve 19. A bracket plate 20 is fixed to the sleeve 18.

  The water pump 11 is disposed on one side surface 1b of the cylinder block 1, and the inflow passage 21 into which the cooling water flows is opened in the direction of the other end surface 1c of the cylinder block 1 (or the direction facing the catalyst case 18). The inflow pipe 22 is connected to the inflow passage 21. The inflow pipe 22 passes through the back of the catalyst case 18 and substantially crosses the cylinder block 1, and its starting end is connected to the end of the side surface 2 b of the cylinder head 2 opposite to the chain case 6. ing.

  Although not shown in the figure, a distribution device with a thermo valve for distributing cooling water to a radiator, a heater or the like is provided at the end of the cylinder head 2 opposite to the chain case 6 and cooled by the radiator. Cooling water (or cooling water whose temperature is low and returns without passing through the radiator) returns from the distributor to the water pump 11 via the inflow pipe 22.

  The internal combustion engine of the present embodiment includes an EGR device that returns a part of the exhaust gas to the intake system, and an EGR pipe 23 for taking out the EGR gas is connected to the lower portion 18b of the catalyst case 18 as a part of the EGR device. . The EGR pipe 23 rises to a position between the catalyst case 18 and the water pump 11 and then extends toward the other end of the cylinder head 2 opposite to the chain case 6. 11, an EGR cooler 24 is inserted in a midway portion.

  The EGR cooler 24 is also inserted in the inflow pipe 22. Accordingly, the entire amount of cold air returns to the water pump 11 via the EGR cooler 24, and the EGR gas is cooled by the cooling water passing through the inflow pipe 22. The EGR gas flows through the EGR cooler 24 from the bottom up, and the cooling water flows through the EGR cooler 24 substantially in the left-right direction (lateral direction) (the cooling water inlet and the cooling water outlet of the EGR cooler 24 are slightly higher in height). Actually, the cooling water is flowing up and down as well.)

The EGR cooler 24 is disposed slightly below the water pump 11. For this reason, the inflow pipe 22 extends obliquely downward from the starting end to the EGR cooler 24, and faces the inflow passage 21 of the water pump 11 in an obliquely upward posture from the EGR cooler 24 .

(2) Details of Water Pump Next, the structure and mounting mode of the water pump 11 will be described with reference to other drawings. For example, as can be understood from FIG. 5, the water pump 11 includes a pump housing 26 fixed to one side 1 b of the cylinder block 1 with a bolt 25, and a cover housing 28 fixed to the pump housing 26 with a bolt 27. In addition, the rotary shaft 29 is rotatably held by the cover housing 28, and the pulley 13 is fixed to the outer end portion of the rotary shaft 29. The overlapping portions of the pump housing 26 and the cover housing 27 are both flanges, and the flanges are fastened with bolts 27.

  As shown in FIG. 6, the inner end of the rotating shaft 29 reaches a pump chamber 30 formed in the pump housing 26, and a blade (impeller) 31 as an example of a pressure feeding member is fixed to the inner end of the rotating shaft 29. Yes. The axial center of the pump chamber 30 is slightly separated from the cylinder block 1 than the axial center of the inflow passage 21. Therefore, the inflow passage 21 is provided with an intermediate passage 32 that is inclined (or bent) in a plan view and continues to the pump chamber 30.

  The pump housing 26 is long in the front-rear direction (the axial direction of the crankshaft 5), and the pump chamber 30 is open to the chain case 6 side. Therefore, the cover housing 28 overlaps the pump housing 26 from the chain case 6 side. As shown in FIGS. 4 and 5, the pump housing 26 and the cover housing 28 are substantially pentagonal when viewed from the side, and are fastened by bolts 27 at the respective apex portions.

  Accordingly, the two are fastened by the five bolts 27, but the two close to the chain case 6 pass through the cover housing 28 and are screwed into the pump housing 26, and the remaining three are pump housing 26. And is screwed into the cover housing 28. The cover housing 28 is shaped like a bell in a side view, and a rotating shaft 29 is supported by an elongated seal bearing 33 inside. In addition, the water pump 11 can also be made into a substantially square shape, a substantially circular shape, etc. by front view.

  The pump housing 26 is long in the front-rear direction, and includes a lateral discharge passage 34 that communicates with the pump chamber 30 and is long in the front-rear direction. The inflow passage 22, the pump chamber 30 and the discharge passage 34 are arranged so as to be shifted in the left-right direction. Therefore, the inflow passage 22 and the pump chamber 30 overlap the discharge passage 34 in a side view.

  More precisely, the discharge passage 34 is located on the side closer to the cylinder block 1 and the inflow passage 22 and the pump chamber 30 are located on the side away from the cylinder block 1 and overlap in the left-right direction. . A discharge port 35 opened toward the cylinder block 1 is open at the tip of the discharge passage 34, and the discharge port 35 communicates with a main gallery (fluid passage) 36 provided in the cylinder block 1.

  As shown in FIG. 5B, a part of the pump chamber 30 and the discharge passage 34 communicate with each other through an escape hole 37, the inflow passage 21 and the discharge passage 34 are arranged substantially in parallel, and The cooling water flow direction is reversed. Therefore, the cooling water that has flowed into the inflow passage 21 flows in a U-shaped manner in a plan view and is sent to the main gallery 36 of the cylinder block 1.

  The inflow passage 21 is formed so that the inlet thereof is shifted to the cover housing 28 side with respect to the discharge port 35. Therefore, the pump housing 26 is located on the cylinder block 1 side from the portion where the inflow passage 21 is provided. The inflow passage 21 is opened in the step surface, and the discharge port 35 is opened in the lowered portion. By stepping down in this way, the inflow passage 21 and the discharge passage 34 are overlapped in the left-right direction of the cylinder block 1 while the inflow passage 21 is shifted toward the cover housing 28 for compactness.

  When the pump housing 26 is fastened, the bolt 25 is rotated with a wrench from the side surface 1b of the cylinder block 1 (from the outside in the left-right direction). For this reason, a space is vacant on the left and right front sides of the pump housing 26, and therefore the outside in the left-right direction of the pump housing 26 is a dead space as a work space. 21 is overlapped with the discharge passage 34 in the left-right direction, and the pump housing 26 is made compact by overlapping the inflow passage and the pump chamber 30 and the discharge passage 34 without interfering with the arrangement of other members. Can be

In other words, for example, if the inflow passage 21 and the discharge passage 34 are arranged apart from each other in the vertical direction, the vertical width of the pump housing 26 inevitably increases, and the pump housing 26 not only increases in size but also other members. In this embodiment, the inflow passage 21 and the pump chamber 30 ng 26 overlap in the left-right direction, and the inlet of the inflow passage 21 is connected to the discharge port 35 in a side view. Since it is shifted to the pulley 13 side from the discharge port 35 without overlapping, the length of the inflow passage 21 is made as short as possible, so that it can be made compact as a whole and the arrangement of other members is not hindered. is there.

  In the embodiment, the inflow pipe 22 is fitted (press-fitted) after the pump housing 26 is fixed with the bolt 25. Therefore, the inflow pipe 22 does not interfere with the fastening of the bolt 25. In this case, two of the bolts 25 for fixing the pump housing 26 are arranged on the side facing the insertion direction of the inflow pipe 22 across the inlet of the inflow passage 21.

Therefore, even if a load is applied to the pump housing 26 when the inflow pipe 22 is inserted, the pump housing 26 is not affected by the separation from the cylinder block 1, and the inflow pipe 22 is strongly applied to the pump housing 26. Can be plugged in. For this reason, even if it is the system of retrofitting the inflow pipe 22, the inflow pipe 22 can be firmly attached with a strong force. Of course, if the arrangement position of the bolt 25 is provided in a portion where it does not interfere with the inflow pipe 22, the inflow pipe 22 can be fitted and fastened first.

  By providing the stepped portion in the pump housing 26, the thickness of the pump housing 26 in a plan view changes. Therefore, for convenience, a tapered portion in a side view located on the cover housing 28 side with respect to the inflow passage 21 is referred to as an enormous portion and is denoted by reference numeral 26a, and a portion that has been stepped down and thinned in a plan view is narrow. And is denoted by reference numeral 26b.

  As shown in FIG. 3, the pump housing 26 is fastened to the cylinder block 1 with three bolts 37. Of the three bolts 37, the two narrow portions 26b are located above and below, and the other one is located at the lower end of the large diameter portion 26a on the side close to the narrow portion 26b. In any part, the part where the bolt 37 overlaps is a flange.

Figure 4 (A) and as best seen in FIG. 6, on the side which overlaps with the cover housing 28 of the pump housing 26, the protruding portion 39 overlaps with part of the chain case 6 in a front view as seen from the crank axial direction A collar 40 that is slightly longer than the thickness of the protruding portion 39 is inserted into the protruding portion 39 in the front-rear direction, and the collar 40 and one side portion of the chain case 6 are connected to the cylinder with the bolt 1. It is fastened together with block 1. Therefore, there is a slight gap e between the head seating surface of the bolt 41 and the outer surface of the chain case 6. A hole into which the collar 40 is fitted is indicated by reference numeral 42.

  The collar 40 is fitted into the protruding portion 39 of the pump housing 26, and the bolt 42 is fitted into the chain case 6.

With this configuration, the pump housing 26 is prevented from being displaced downward by the bolts 42 and the collar 40. Therefore, even if a downward force is applied to the pulley 13 due to the rotation of the accessory drive belt 10, the force is not increased. The pump housing 26 is held in a stable state without acting on the pump housing 26.

  As a result, cooling water leakage due to misalignment between the inflow pipe 22 and the inflow passage 21, cooling water leakage due to displacement of the pump housing 26, or distortion of the rotary shaft 29 due to distortion in the pump housing 26 and the cover housing 28. Such a problem can be prevented.

As mentioned above, although embodiment of this invention was described, this invention can be embodied variously besides the above. For example, it is possible to use a joint to connect the inflow passage and the inflow pipe, or to form a boss portion in the inflow passage and fit a hose-like inflow pipe into the boss. The present invention can also be applied to other pump units such as an oil pump. Pump unit is also possible to drive by chain, in this case, can we fix the sprocket to the rotary shaft instead of the pulley.

  The inlet of the inflow passage can be downward, upward, or laterally outward. The discharge port does not necessarily need to be opened toward the cylinder block, and a pipe may be connected to the discharge port as upward, downward, or sideways.

The present invention can be applied to an internal combustion engine provided with a pump unit such as a water pump. Therefore, it can be used industrially.

DESCRIPTION OF SYMBOLS 1 Cylinder block 1a One end surface 1b One side surface parallel to a crank axis 2 Cylinder head 5 Crank shaft 6 Chain case 10 Auxiliary drive belt 11 Water pump as an example of a pump unit 13 Pulley 21 Inflow passage 22 Cooling water inflow pipe 24 EGR Cooler 25 Bolt for water pump fastening 26 Pump housing of water pump 28 Cover housing 29 Rotating shaft 30 Pump chamber 31 Impeller (impeller) as an example of pressure feeding member
34 Discharge passage 35 Discharge port
39 Protruding part
40 colors
41 volts

Claims (1)

A cylinder block in which a crankshaft is rotatably held, a chain case fixed to one end surface of the cylinder block, and a pump unit disposed on one side surface parallel to the crankshaft of the outer peripheral surface of the cylinder block. Have
The pump unit has a housing having a pump chamber therein, a pumping member disposed in said pump chamber, and a pulley or sprocket for rotating the pre-Symbol pumping member,
The housing is formed with an inflow passage for guiding fluid to the pump chamber and a discharge passage for pumping fluid from the pump chamber. The housing has a rotation axis of the pulley or sprocket parallel to the crankshaft. while in attitude are bolted to one side of the cylinder block,
Wherein the pulley or sprocket, by arranging the outer side than the chain case, a configuration in which power is transmitted by a belt or chain from the crankshaft to the pulley or sprocket,
Wherein the inflow passage and the discharge passage is a horizontal position and open on the opposite side of the pulley or sprocket, and the inflow passage with the discharge passage is positioned closer to the cylinder block is positioned farther from the cylinder block the way, the and overlap in a direction perpendicular to one side surface of the cylinder block, furthermore, the the tip of the discharge passage has a discharge port opened, the inlet of the inflow passage, than the discharge port Shifted to the pulley or sprocket side ,
Further, the housing has a protruding portion that overlaps the outer surface of the chain case when viewed from the crank axis direction, and the protruding portion is attached to the chain case by a bolt so that the protruding portion does not shift in a direction perpendicular to the crank axis line. Connected,
Internal combustion institutions.

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