JP2797778B2 - Internal combustion engine lubrication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an internal combustion engine Kurankushi
The present invention relates to improvement of a lubrication device for a shaft .

[0002]

2. Description of the Related Art In a lubrication path of a crankshaft, lubricating oil supplied from an oil pump is first supplied to a crank journal, and a part of the lubricating oil supplied to the crank journal is passed through an oil passage in the crankshaft. A structure for supplying to a crankpin is widely used.

Conventionally, there is an internal combustion engine in which a bearing of a crank journal is divided from an cylinder block into an upper bearing and a lower bearing, and after mounting a piston from below the cylinder, each bearing is fastened to the cylinder block via a bolt. (See Japanese Utility Model Application Laid-Open No. 62-69045).

However, when the bearing of the crank journal is provided separately from the cylinder block, if the materials of the two are different, the bearing may be affected by the difference in thermal expansion, or the coupling rigidity of the bearing may be insufficient and the surface between the bearing and the crank journal may be insufficient. Pressure increases,
There is a possibility that the lubricating oil guided to the sliding contact portion of the crank journal receives frictional heat and becomes considerably high in temperature. However, in the conventional device, the lubricating oil that has become hot between the crank journal and the bearing is supplied to the sliding contact portion between the crankpin and the connecting rod through the oil passage in the crankshaft. May increase excessively, increase the wear due to the decrease in the viscosity of the lubricating oil, and stop the deterioration of the lubricating oil.

[0005] The appropriate value required for the lubricating oil temperature is:
Not only the temperature condition of the oil passage but also the lubricating portion of the engine varies depending on the surface pressure and sliding contact speed (JP-A-61-247809, JP-A-58-21115).
Publication No.).

The present invention has been made in view of the above points, and has as its object to appropriately maintain the temperature of lubricating oil supplied to a crankpin.

[0007]

According to the present invention, an upper bearing and a lower bearing for rotatably supporting a crank journal of a crankshaft are formed separately from the cylinder block, and the upper bearing and the lower bearing are cylinder-blocked by bolts.
And lubricate oil from the oil pump.
A lubricating oil passage to send to the oil gallery of the
The oil passage that supplies the lubricating oil from the oil gallery to the sliding portion of the crank journal and the oil gallery
Lubricating oil between the crank journal and the crankpin
An oil passage which directly communicates with the oil through hole and supplies the sliding contact portion of the crank pin is arranged in parallel with the upper bearing .

In the above lubricating device, a pair of auxiliary bolts which penetrate through the left and right side wall portions of the cylinder block and are screwed to the upper bearing are provided, and one of the oil passages for supplying lubricating oil to the sliding contact portion of the crank journal is provided. And an oil passage for supplying the lubricating oil to the sliding portion of the crankpin is formed through the other auxiliary bolt.

In the above lubricating apparatus, the auxiliary bolt
Fitted with heating means for heating the lubricating oil around the lubricating oil temperature is provided a control means for actuating the heating means when less than the predetermined value.

[0010]

By providing an oil passage for supplying lubricating oil sent from an oil pump to the crank journal and an oil passage for supplying lubricating oil to the crankpin in parallel, the lubricating oil guided to the crankpin can slide on the crank journal or the like. Heating by the frictional heat generated in the contact portion can be suppressed, and the lubricating oil temperature guided to the crank journal and the crankpin can be appropriately maintained.

An auxiliary bolt for fastening the upper bearing to the cylinder block is provided, and the oil passage is formed through the auxiliary bolt, thereby increasing the coupling rigidity of the upper bearing and securing a space for disposing the oil passage. Can be compatible.

Further, by providing a means for heating the lubricating oil through the auxiliary bolt and a control means for operating the heating means when the lubricating oil temperature is lower than a predetermined value, the lubricating oil can be sufficiently warmed from a warm-up time. Lubricating oil can be supplied to the crank journal or each crank pin to improve fuel economy and idle stability during warm-up.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, a crank journal of a crankshaft is rotated around a lower end of a cylinder 11.
An upper bearing 4 and a lower bearing 5 that are freely supported are provided separately from the cylinder block 10. Cylinder block 1
Reference numeral 0 denotes a so-called head-integrated type in which a cylinder head portion that defines a combustion chamber (not shown) is integrally formed.

As shown in FIG. 2, a crankshaft 1 provided in a four-cylinder engine has five crank journals 3.
And four crank pins 2 that support each connecting rod.

Left and right side wall portions 10 of cylinder block 10
A and 10B are formed with two oil galleries 12, 13 along the cylinder row direction. After passing through the oil filter 15, the lubricating oil discharged from the oil pump 14 is guided to each of the crank journals 3 through one oil gallery 12 and the other oil gallery 13.
Through each crank pin 4. The oil gallery 12 is a right side wall 10A to which an exhaust pipe (not shown) is connected.
The oil gallery 13 is located on the left side wall 10B to which an intake pipe (not shown) is connected.

The lubricating oil cooled through the oil cooler 16 is guided to one oil gallery 13.

Each of the upper bearings 4 is formed with oil through holes 21, 22, 23, 24, 25, 26, and 27 for guiding lubricating oil from the oil gallery 12 to sliding portions of the crank journals 3, respectively.

As shown in FIG. 3, the two oil passages 22 for guiding the lubricating oil to the sliding portion of the # 2 crank journal 3 are provided.
Reference numeral 23 denotes a sliding contact portion between the crank journal 3 and the bearing metal 9 via semicircular oil grooves 31 and 32 formed on the inner peripheral surface of the upper bearing 4 and a plurality of oil holes 33 and 34 opening to the bearing metal 9. Communicate with

In each of the upper bearings # 2 and # 4, oil through holes 28 and 29 for guiding lubricating oil from the oil gallery 13 to the respective crank pins 4 are formed.

The # 2 upper bearing 4 has two oil through holes 2
One oil through hole 28 is formed between 2 and 23, a single oil hole 35 opening in bearing metal 9, an oil groove 36 formed annularly in the inner peripheral surface of bearing metal 9, and a crank. The crank pins 4 communicate with the sliding portions of the connecting rods through oil through holes 37 formed inside the shaft 1.
The oil through hole 37 has an opening 37A for the crank journal 3 and an opening 37B for each crankpin 4. The opening 37A opens into the annular oil groove 36.

The upper bearing 4 and the lower bearing 5 are formed by a pair of bolts 4.
1 to the cylinder block 10. The head 41A of each bolt 41 is seated on the lower surface of the lower bearing 5, and the tip screw portion 41B is screwed into a screw hole 42 formed in the cylinder block 10.

A cylindrical gap 43 is defined between the shaft 41C of each bolt 41, the upper bearing 4 and the cylinder block 10. The cylinder block 10 is provided with oil through holes 18 and 19 respectively connecting the gaps 43 and the oil galleries 12 and 13, and the oil galleries 12 and 13 are connected to the oil through holes 28 of the upper bearing 4 through the gaps 43. Alternatively, they communicate with the oil through holes 22, 23 and the like.

Next, the operation will be described.

The lubricating oil circulating in the engine is supplied to the cylinder 1 of the cylinder block 10 in which the cylinder head is integrally formed.
1 and the heat transmitted through the wall around the combustion chamber, the frictional heat generated by the sliding of the various parts, and the high temperature when exposed to the combustion gas.
Since heat is radiated to the outside from the outer wall of 0 and the outer wall of the oil pan,
The oil temperature is balanced in a predetermined range.

As a result, the oil gallery 12 of the cylinder block 10 allows the oil through holes 21, 22, 23, 2
4, 25, 26, 27 through each crank journal 3
The temperature of the lubricating oil guided to the sliding contact portion is maintained in a predetermined range.

On the other hand, the lubricating oil guided to the oil cooler 16 is actively cooled, so that the lubricating oil kept at a relatively low temperature flows from the oil gallery 13 to the oil through holes 28, 29, Each of the crank pins 2 is guided to a sliding contact portion between the connecting rod and each of the connecting rods through each of the oil through holes 37 in the crank shaft 1.

Since the upper bearing 4 is provided separately from the cylinder block 10 together with the lower bearing 5, when the materials are different from each other, the upper bearing 4 may be affected by a difference in thermal expansion, or the coupling rigidity obtained via each bolt 41 may be insufficient. In this case, the surface pressure between each bearing metal 9 and the crank journal 3 increases due to the deformation of the bearing surface, and the lubricating oil lubricating the sliding contact portion of each crank journal 3 receives frictional heat and becomes considerably high in temperature. there is a possibility.

In the conventional apparatus, the lubricating oil, which has become considerably hot at the sliding contact portion of the crank journal, is supplied to the sliding contact portion between the crankpin and the connecting rod through an oil passage in the crankshaft. The lubricating oil whose temperature has risen after the lubrication is released from around the crank journal 3 and returned to the oil pan, while the lubricating oil guided to the sliding contact portion of each crank pin 4 is fed from the oil groove 36 of the bearing metal 9 to the crankshaft. Since the oil is guided through the oil through hole 37 in the shaft 1, the oil quickly passes around the crank journal 3 and is prevented from being heated by frictional heat generated in the sliding contact portion of the crank journal 3.

Accordingly, it is possible to reduce the friction by keeping the viscosity of the lubricating oil film formed at the sliding contact portion between each crank journal 3 and the bearing metal 9 low,
And preventing the seizure or the like without excessively reducing the viscosity of the lubricating oil film formed on the sliding contact portion of the connecting rod.

Next, another embodiment shown in FIG. 4 will be described.

The upper bearing 4 and the lower bearing 5 are fastened to the cylinder block 10 via a pair of bolts 41 inserted from below the cylinder block 10, and the upper bearing 4 is connected to the left and right side wall portions 10A, 10A of the cylinder block 10. 10B
Is fastened to the cylinder block 10 through a pair of auxiliary bolts 51 penetrating the cylinder block 10 to increase the coupling rigidity.

The joint surface 52 of the upper bearing 4 to the cylinder block 10 is inclined in a mountain shape, and each auxiliary bolt 51 is perpendicular to the joint surface 52.

Each auxiliary bolt 51 is connected to the cylinder block 1
0A head 51A seated on left and right side walls 10A, 10B
And a screw portion 51B screwed into each screw hole 54 of the upper bearing 4.
And a shaft portion 51C connecting these. Each of the auxiliary bolts 51 has a concave portion 51D which is depressed facing each of the oil galleries 12, 13 of the cylinder block 10, and a through hole 55 which connects the concave portion 51D and the tip end surface of the screw portion 51B is formed.

As shown in FIG. 5, the oil gallery 12
At the bottom of the screw hole 54 communicating with the
6 and 57 are opened, and one ends of the oil through holes 56 and 57 are respectively opened in semicircular oil grooves 58 and 59 formed on the inner peripheral surface of the upper bearing 4 as in the above-described embodiment. It communicates with a sliding contact portion between the crank journal 3 and the bearing metal 9 through a plurality of oil holes 33 and 34 that open.

Screw hole 54 communicating with oil gallery 13
One oil through hole 60 is opened at the bottom of the oil hole 35. One end of the oil through hole 60 is formed in an annular shape on the inner peripheral surface of the bearing metal 9 and the oil hole 35 opening into the bearing metal 9 as in the above embodiment. Each of the crank pins 4 is connected to an oil groove 36 through an oil through hole 37 formed inside the crankshaft 1.
And the connecting part of the connecting rod.

In this case, since the lubricating oil is guided through the inside of each auxiliary bolt 51, the number of bolts for fastening the upper bearing 4 is increased in the limited space of the head-integrated cylinder block 10 to increase the number of bolts. 4 can be increased in rigidity, and a space for arranging an oil passage for guiding lubricating oil to a sliding portion of each crank pin 4 can be ensured. Further, the number of processing steps for the oil passage can be reduced.

Next, another embodiment shown in FIG. 6 will be described.

In the upper bearings # 1 and # 5, two oil passages 68 and 69 are formed to guide the lubricating oil that has passed through the oil cooler 16 to each of the crankpins 2. The # 1 crank journal 3 and the large diameter journal 80 at the rear end are connected via ring-shaped seal rings 70 and 71, respectively.

As shown in FIG. 7, one seal ring 70 is interposed adjacent to the bearing metal 9 of the # 1 crank journal 3, and an annular groove 72 is defined between the seal ring 70 and the other seal ring 71. You.

An oil through hole 73 for guiding lubricating oil from the # 1 crank journal 3 to each of the # 1 and # 2 crankpins 2 inside the crankshaft 1 and a large diameter journal 80
Oil through holes 74 for introducing lubricating oil to the respective crank pins 2 of # 3 and # 4 are formed.

In each of the upper bearings 4, oil through holes 75, 76, 77, 78, 79 for supplying the lubricating oil guided from the oil gallery 12 to the sliding portions of the respective crank journals 3 are formed.

As a result, the lubricating oil guided to each crank pin 2 does not pass between the crank journal 3 and the bearing metal 9, and the absorption of friction heat of the crank journal 3 can be further reduced.

As shown in FIG. 8, the bottom of the screw hole 54 of the auxiliary bolt 51 communicating with the oil gallery 13 is
One oil passage hole 67 is formed to be inclined, and an oil groove 66 for opening the oil passage hole 67 is formed on the inner peripheral surface of the upper bearing 4. Lubricating oil is supplied from the oil groove 66 to the crank journal 3 in the same manner as in the above-described embodiment. The bearing metal 9 may be bypassed and supplied to the sliding contact portion between each crank pin 4 and the connecting rod.

Next, another embodiment shown in FIG. 9 will be described.

The lubricating oil from the oil gallery 12 is passed through the through holes 55 in the auxiliary bolts 51 to each of the crank journals 3.
And the lubricating oil from the oil gallery 13 is supplied to the sliding contact portion of each crankpin 4 through a through hole 55 in another auxiliary bolt 51, and an electric heater is provided around each auxiliary bolt 51. 81 and 82 are each wound in a coil shape.

[0047] Each electric heater 81 is respectively energized controlled by the thermostats 83 and 84, each thermostat 83 and 84 enter the detection signal Tf ₀ of the oil temperature sensor 85 provided on the outlet side of the oil filter 15, During warm-up when the oil temperature is equal to or lower than a set value, the heaters 81 and 82 are independently energized to heat the lubricating oil.

This control operation will be described with reference to the flowchart of FIG. 10. If the detected oil temperature Tf ₀ is lower than 80 ° C. in step 1 during warm-up, the process proceeds to step 2 where the thermostat 84 energizes the heater 82. At the same time, the thermostat 83 energizes the heater 81, and
If the detected oil temperature Tf ₀ is lower than 110 ° C. in step 3, the process proceeds to step 4 where the thermostat 83 sets the heater 8
1 is energized. As a result, the lubricating oil passing through the through holes 55 in the auxiliary bolts 51 is heated by the heaters 81 and 82, and the lubricating oil sufficiently warmed from the warm-up time slides on the crank journals 3 and the crank pins 4. Friction that is supplied to the contact portion and generated in the sliding contact portion is reduced, and fuel economy and idle stability during warm-up can be improved.

If the detected oil temperature Tf ₀ rises above 80 ° C. in step 5 as the warm-up proceeds, the process proceeds to step 6 where the thermostat 84 stops supplying power to the heater 82, and in step 7 the detected oil temperature When Tf ₀ rises above 110 ° C., the routine proceeds to step 8 where the thermostat 83 stops energizing the heater 81. This prevents the lubricating oil from being overheated after warming up.

[0050]

As described above, according to the present invention, the upper bearing and the lower bearing for rotatably supporting the crank journal of the crankshaft are formed separately from the cylinder block, and the upper bearing and the lower bearing are formed by the cylinder block by bolts.
Connect the lubricating oil from the oil pump
Lubricating oil passage to be sent to the oil gallery of the cylinder block
It provided an oil passage for supplying lubricating oil from the oil gallery to the sliding contact portion of the crank journal, or oil gallery
Connect the lubricating oil to the crank journal and crank pin
An oil passage that directly communicates with the oil through hole and supplies the sliding portion of the crank pin is arranged in parallel with the upper bearing, so that the viscosity of the lubricating oil film formed on the crank journal is kept low to reduce friction. In addition, ensuring the viscosity of the lubricating oil film formed at the sliding contact portion between the crankpin and the connecting rod can improve the fuel efficiency of the engine, and can effectively prevent seizure and the like and deterioration of lubrication.

In the above lubricating device, a pair of auxiliary bolts which penetrate through the left and right side wall portions of the cylinder block and are screwed to the upper bearing are provided, and one of the oil passages for supplying the lubricating oil to the sliding contact portion of the crank journal is provided. An oil passage for supplying lubricating oil to the sliding contact portion of the crankpin is formed via the other auxiliary bolt, so that the coupling rigidity of the upper bearing is increased and the oil passage is provided. Space can be ensured at the same time.

In the above lubricating apparatus, the auxiliary bolt
Fitted with heating means for heating the lubricating oil around the, for the lubricating oil temperature is provided a control means for actuating the heating means when less than the predetermined value, the crank journal or each lubricant warmed sufficiently from the time of warm-up Supply to the crank pin,
Fuel economy during warm-up and idle stability can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an engine showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the engine including the lubricating oil path.

FIG. 3 is a longitudinal sectional view of a main part of the same.

FIG. 4 is a cross-sectional view of an engine showing another embodiment.

FIG. 5 is a sectional view along the line AA in FIG. 4;

FIG. 6 is a longitudinal sectional view of an engine including a lubricating oil path according to still another embodiment.

FIG. 7 is a longitudinal sectional view of a main part of the same.

FIG. 8 is a sectional view of a main part showing still another embodiment.

FIG. 9 is a cross-sectional view of an engine including a control circuit according to still another embodiment.

FIG. 10 is a flowchart showing a control operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Crankshaft 2 Crank pin 3 Crank journal 4 Upper bearing 5 Lower bearing 9 Bearing metal 10 Cylinder block 10A Cylinder block side wall 10B Cylinder block side wall 12 Oil gallery 13 Oil gallery 14 Oil pump 22 Oil through hole 23 Oil through hole 28 Oil Through hole 37 Oil through hole 51 Auxiliary bolt 55 Oil through hole 81 Electric heater 82 Electric heater 83 Thermostat 84 Thermostat 85 Oil temperature sensor

Continuation of the front page (56) References JP-A-3-37407 (JP, A) Japanese Utility Model Application Sho 62-69045 (JP, U) Japanese Utility Model Application Utility Model Sho 57-5901 (JP, U) (58) Fields investigated (Int) .Cl. ⁶ , DB name) F01M 1/06 F01M 5/00

Claims (3)

(57) [Claims] 1. A top bearing and a lower bearing rotatably supporting a crank journal of the crankshaft is formed by dividing this cylinder block, ball the upper bearing and a lower bearing
To the cylinder block with lubrication and lubrication.
Oil is transferred from the oil pump to the oil block of the cylinder block.
Lubricating oil passage to feed oil, lubrication from oil gallery
An oil passage that supplies oil to the sliding contact of the crank journal, and lubricating oil from the oil gallery
And an oil passage that directly communicates with an oil through hole connecting the crank pin and supplies the sliding portion of the crank pin to the upper bearing. Lubrication equipment. 2. A pair of auxiliary bolts which penetrate right and left side wall portions of a cylinder block and are screwed to an upper bearing are provided, and an oil passage for supplying lubricating oil to a sliding contact portion of a crank journal is provided through one auxiliary bolt. 2. The lubricating device for an internal combustion engine according to claim 1, wherein an oil passage for supplying lubricating oil to a sliding portion of the crank pin is formed through the other auxiliary bolt. 3. Install the heating means for heating the lubricating oil around the auxiliary bolt, according to claim 2 in which the lubricating oil temperature is characterized in that a control means for actuating the heating means when less than the predetermined value Internal combustion engine lubrication system.