JP2020060116A - Internal combustion engine for automobile - Google Patents

Abstract

To dispose a vacuum pump assisting a brake booster in a state that vibration in driving does not spread inside of a vehicle.SOLUTION: An internal combustion engine is disposed at the back of a vacuum pump 15, a cylinder block 1 and a front cover 3. The front cover 3 has upper and lower auxiliary boss portions 19 projecting backward from a front side wall 12a, and a bracket portion 18 of the vacuum pump 15 is fixed to rear faces of the auxiliary boss portions 19 by bolts. The auxiliary boss portions 19 and their upper and lower main boss portions 13 are connected by inclined ribs 21. As the vacuum pump 15 is fixed to the front cover 3, vibration peculiar to the vacuum pump 15 does not reach the inside of the vehicle through a car body frame. Accordingly, an occupant does not feel discomfort due to the vibration caused by the vacuum pump 15.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an internal combustion engine mounted on an automobile.

  In the foot brakes of automobiles, the pedaling force is increased by a brake booster that uses intake negative pressure, but in recent years, due to the spread of superchargers, there is a situation where the intake negative pressure alone cannot cover the negative pressure of the brake booster. Therefore, an electric vacuum pump is provided as an auxiliary vacuum source for the brake booster. As an example, Patent Document 1 discloses that a vacuum pump is attached to a vehicle body frame.

JP, 2014-227153, A

  Since the vacuum pump is not an indispensable constituent element of the internal combustion engine, its location can be set arbitrarily. However, in the configuration of Patent Document 1, when the vacuum pump is driven, its vibrations are transmitted through the vehicle body frame to the inside of the vehicle. Therefore, there is a concern that the passengers may feel uncomfortable.

  In particular, since the vacuum pump of the type in which the piston reciprocates has a large vibration, there is a strong concern that the vibration will spread to the inside of the vehicle. Further, in a small vehicle such as a light vehicle, it is difficult to use a large amount of vibration isolator to secure a large space inside the vehicle, so it can be said that the problem of vibration caused by driving the vacuum pump is likely to appear strongly.

  Further, in Patent Document 1, since it is necessary to manufacture a special bracket or process a tap hole in the vehicle body frame, there is a possibility that the cost for mounting may increase.

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

The invention of this application specifies its typical form in each claim. Of these, the invention of claim 1 is
"It is located in the engine room in the front of the vehicle body, and the front cover that covers the timing chain is fixed to the front of the cylinder block and cylinder head."
In the basic configuration
“The front cover is provided with an auxiliary boss portion protruding from a portion where the cylinder block or the cylinder head overlaps, and a brake booster is assisted on the rear surface of the auxiliary boss portion on the side overlapping the cylinder block or the cylinder head. The vacuum pump is fixed. ''
It is configured as.

The invention of claim 2 embodies claim 1;
"A seal applied to the overlapping surface of the front cover and the cylinder block or the cylinder head on a portion of the rear surface of the auxiliary boss portion of the front cover which is closer to the cylinder block or the cylinder head than the overlapping surface with the vacuum pump. It forms a groove into which the agent can flow. "
It is configured as.

The invention of claim 3 has the same basic configuration as that of claim 1,
"The front cover is provided with upper and lower auxiliary boss portions protruding from the overlapping portion with the cylinder block or the cylinder head, and a vacuum pump having a piston that reciprocates substantially vertically is fixed to the upper and lower auxiliary boss portions. ing"
Is added. In addition, "upper and lower" specified in claim 3 does not mean only two upper and lower locations, but means a plurality of upper and lower locations.

The invention of claim 4 is based on any one of claims 1 to 3,
“Main bosses for fixing the front cover to a cylinder block or a cylinder head are arranged on both upper and lower sides of the auxiliary boss, and the auxiliary boss and the main boss are connected by ribs.”
It is configured as.

  Since an internal combustion engine for an automobile is supported by a vehicle body frame via a vibration-proof rubber, even if vibration is generated by driving the vacuum pump, the vibration inherent to the vacuum pump is not transmitted to the inside of the vehicle. Further, even if vibration is generated by driving the vacuum pump, the internal combustion engine itself usually vibrates more than the vacuum pump, so the vibration of the vacuum pump is absorbed by the vibration of the internal combustion engine. Further, since the front cover has a sturdy structure, the vacuum pump can be firmly fixed, so that the vibration itself can be suppressed.

  As a result, the vibration caused by driving the vacuum pump is not transmitted to the inside of the vehicle, and it is possible to prevent the occupant from feeling uncomfortable.

  Further, there is an advantage that the dead space existing in the peripheral portion of the front cover can be effectively used. In particular, when the vacuum pump is attached to the rear surface of the front cover as in claim 1, the vacuum pump can be arranged at a position where it does not interfere with the accessory drive belt, which is particularly advantageous in terms of effective use of space.

  By the way, in Patent Document 1, the vacuum pump is fixed to the side frame of the vehicle body, but with this, the center of gravity of the vehicle is slightly displaced from the vertically long center line to the left and right outside, and stability during turning is improved. There is a risk of a slight decrease.

  On the other hand, when the vacuum pump is fixed to the rear surface of the front cover as in the present invention, the vacuum pump can be brought close to the longitudinal centerline of the vehicle regardless of whether the internal combustion engine is horizontal or vertical. Therefore, it is possible to prevent a decrease in stability during turning. When the internal combustion engine is of a horizontal type, fixing the vacuum pump to the rear surface of the front cover is particularly advantageous because it brings the vacuum pump closer to the longitudinal centerline of the vehicle.

  Although a liquid sealing agent is applied to the superposed surfaces of the front cover, the cylinder block, and the cylinder head, the sealing agent may squeeze out of the superposed surfaces after fixing. Then, the vacuum pump is attached after fixing the front cover to the cylinder block and the cylinder head. However, if the sealant is flowing to the auxiliary boss portion, the vacuum pump may be attached incorrectly.

  On the other hand, if the configuration of claim 2 is adopted, even if the sealing agent runs off the outside of the overlapping surface, it is possible to prevent the overflowing sealing agent from flowing into the concave groove and reaching the auxiliary boss portion, so the vacuum pump Can be fixed in an accurate posture without inclination. Further, since the front cover is thin at the concave groove portion, it is possible to absorb the vibration caused by driving the vacuum pump at the concave groove portion.

  In the invention of claim 3, the piston of the vacuum pump reciprocates substantially vertically so that vertical vibration is generated. However, since the auxiliary boss portion is arranged vertically, the vacuum pump touches as much as possible. It can be firmly fixed in a suppressed state. Therefore, it can greatly contribute to the suppression of vibration. The claims 1 and 3 do not contradict each other. Combining the two is particularly beneficial.

  The front cover has its side portions fixed to the cylinder block and the cylinder head with a large number of bolts. Therefore, a large number of main boss portions for fixing to the cylinder block and the cylinder head are formed on the side portions of the front cover.

  Then, the main boss portion is strongly pressed by the bolt so that it has a sturdy structure. However, when the auxiliary boss portion and the main boss portion are connected by a rib as in claim 4, the rigidity of the portion where vibration of the vacuum pump spreads is increased. Since it is much higher, the vacuum pump can be mounted more firmly.

  Further, according to the fourth aspect, since the ribs are located outside the cylinder block and the cylinder head, the area of the portion of the auxiliary boss that spreads vertically increases, and vibration of the vacuum pump can be greatly absorbed. As a result, it is possible to prevent vibration from spreading to the overlapping portion between the front cover and the cylinder block or the cylinder head, and prevent the distortion of the sealing surface between the front cover and the cylinder block or the cylinder head.

It is the side view which looked at embodiment from the side of the air intake side. It is the rear view which looked at the front cover from the II-II viewing direction of FIG. FIG. 6 is a separated side view of the front cover and the vacuum pump as seen from the side of the intake side. It is the perspective view seen from the side of the intake side. It is the perspective view seen from the front side. It is the perspective view seen from the front side in the state where the vacuum pump was omitted. It is the perspective view seen from the side of the intake side in the state where the vacuum pump is omitted.

  Next, an embodiment of the present invention will be described with reference to the drawings. The internal combustion engine is arranged in the engine room provided in the front part of the automobile, but in the present embodiment, the internal combustion engine is arranged in a horizontal position in which the crankshaft is arranged in a long posture in the left-right direction of the vehicle body. Is. Further, the relationship between the intake air and the exhaust air is a front exhaust air / rear intake air with the exhaust side surface positioned on the front side in the traveling direction with reference to the forward traveling direction of the vehicle.

  On the other hand, in the internal combustion engine, it is generalized that the side on which the timing chain is arranged is called the front and the side on which the mission is arranged is called the rear, with the crank axis direction as the front-rear direction in order to specify the direction. The cover that covers the timing chain is called the front cover.

  Also in this embodiment, this general usage is used for the direction of the internal combustion engine, but as described above, since the internal combustion engine of the embodiment is horizontal, the front-rear direction of the vehicle and the front-rear direction of the internal combustion engine are 90 degrees. ° Different. The front-back direction is clearly shown in FIG. The left-right direction is a direction orthogonal to the crank axis and the cylinder bore axis.

(1). Overview The basic mode of the internal combustion engine of this embodiment is the same as before, and as shown in FIG. 1, a cylinder block 1 and a cylinder head 2 fixed to the upper surface thereof, and a cylinder block 1 and a cylinder. A front cover 3 fixed to the front surface of the head 2 is provided. An oil pan 4 is fixed to the lower surface of the cylinder block 1, while a head cover (not shown) is fixed to the upper surface of the cylinder head 2. The lower portion of the front cover 3 is also fixed to the front surface of the oil pan 4. The cylinder block 1, the cylinder head 2, the front cover 3, and the head cover constitute a main part of the engine body.

  The cylinder head 2 of the present embodiment is of a stacking system of an upper member 2a and a lower member 2b, and an intake manifold 5 is fixed to the intake side surface of the lower member 2b. The upper surface of the cylinder head 2 is indicated by reference numeral 6, the boundary line between the upper and lower members 2a and 2b constituting the cylinder head 2 is indicated by reference numeral 7, and the boundary line between the cylinder block 1 and the cylinder head 2 is indicated by reference numeral 8.

  As can be understood from the form of the intake manifold 5, the internal combustion engine of this embodiment has four cylinders. The member indicated by reference numeral 9 in the upper right portion of FIG. 1 is a bracket that supports the EGR valve, and the member indicated by reference numeral 10 in the lower right portion of FIG. 1 is an oil filter.

  As shown in FIG. 2, a window hole 11 for attaching the intake valve VVB device is formed in a portion of the upper portion of the front cover 3 near the intake side surface. Although not intentionally explained, the front cover 3 has a shallow shell-like shape that opens toward the cylinder block 1 and the cylinder head 2. Therefore, the left and right longitudinal side portions of the front cover 3 have cylinder blocks 1 and Front and rear side walls 12a, 12b overlapping the cylinder head 2 are formed, and a main boss portion 13 for fixing the side wall 12 with bolts is formed on the side walls 12a, 12b.

(2). Vacuum Pump Next, the mounting structure of the vacuum pump 15 will be described with reference to other drawings. As shown in FIG. 1, the vacuum pump 15 is arranged on the rear side and the front side of the cylinder block 1. As can be easily understood from FIGS. 4 and 5, the vacuum pump 15 has a drum portion 16 in a substantially horizontal posture and a cylinder portion 17 protruding substantially upward from the drum portion 16. While the electric motor and the crank mechanism part are built in, the cylinder part 17 contains a piston that reciprocates by the crank mechanism. Although not shown, the cylinder portion 17 and the brake booster are connected by a hose (pipe line).

  As clearly shown in FIG. 1, the drum portion 16 has a posture in which its axis extends long in the same front-back direction as the crank axis direction, and is arranged so as to straddle both the cylinder block 1 and the front cover 3. .

  Then, for example, as shown by the alternate long and short dash line in FIG. 2, upper and lower bracket portions 18 are projectingly provided at a portion of the drum portion 16 which is close to the cylinder portion 17, and as clearly shown in FIGS. , Upper and lower auxiliary boss portions 19 are projected forward at a portion of the front side wall 12a of the front cover 3 which overlaps with the cylinder block 1, and the bracket portion 18 is overlapped on the rear surface of the auxiliary boss portion 19 so that It is fastened with a bolt 20 inserted through the portion 19. Therefore, the bracket portion 18 has a tapped hole into which the bolt 20 is screwed.

  As shown in FIGS. 2, 6 and 7, main boss portions 13 are arranged on both upper and lower sides of the auxiliary boss portion 19, and the auxiliary boss portion 19 and the upper and lower main boss portions 13 have ribs 21 of a substantially triangular shape. Are connected together via. Therefore, the front cover 3 is provided with two upper and lower projecting portions 22 having a triangular shape (or a mountain shape) as viewed from the front and having the auxiliary boss portion 19 as the apex so as to project to the outside of the cylinder block 1.

  Then, as clearly shown in FIG. 2 and FIG. 7, in the portion between the cylinder block 1 and the auxiliary boss portion 18 of the overhanging portion 22, the auxiliary boss portion 19 and the front side wall 12 are vertically elongated so as to be divided. The concave groove 23 is formed. The depth of the groove 23 is several mm.

(3). Summary In the above configuration, since the vacuum pump 15 is attached to the front cover 3 that constitutes the engine body, even if vibration is generated by driving the vacuum pump 15, the vibration is transmitted via the body frame. It does not spread inside the car. Therefore, the vibration caused by the driving of the vacuum pump 15 does not give an uncomfortable feeling to the occupant (because the vibration of the internal combustion engine is larger than the vibration of the vacuum pump 15 in the first place, the vibration of the vacuum pump 15 does not occur). It can be said that it is absorbed by the vibration of and does not spread to the inside of the car as an independent vibration.)

  Further, since the front side of the intake manifold 5 is a kind of dead space, the vacuum pump 15 can be arranged by effectively utilizing the dead space. Therefore, it can contribute to the effective use of the space in the engine room. Although the accessory drive belt is arranged on the front surface of the front cover 3, there is a certain amount of space between the accessory drive belt and the front surface of the front cover 3, and therefore, as in the present embodiment, a vacuum is used. Arranging part of the pump 15 so as to straddle the front cover 3 in a rear view has an advantage that the vacuum pump 15 can effectively use the space without interfering with the intake manifold 4 and the accessory drive belt.

  In assembling the internal combustion engine, a liquid sealant is applied to the overlapping surfaces of the side walls 12a and 12b of the front cover 3 with the cylinder block 1 and the cylinder head 2, and the front cover 3 is attached to the cylinder block 1 with the main bolt 24. When it is fastened to the cylinder head 2, a part of the applied seal may protrude to the outside. Therefore, if the protruding sealant reaches the auxiliary boss portion 19, there is a concern that the adhesion between the bracket portion 18 of the vacuum pump 15 and the auxiliary boss portion 19 is hindered, resulting in a defective mounting.

  On the other hand, when the vertically long concave groove 23 is formed between the front side wall 12a and the auxiliary boss portion 19 as in the present embodiment, even if the sealant protrudes to the outside of the front side wall 12a, the protruding seal Since the agent is not stopped by the concave groove 23 and reaches the auxiliary boss portion 18, the vacuum pump 15 can be accurately attached.

  Although a weir plate can be provided as a method of stopping the protruding sealing agent, it is not realistic to provide the weir plate because the end surface of the front cover 3 is finished by milling. Further, by forming the concave groove 23, an increase in weight of the front cover 3 can be suppressed, which is also advantageous in terms of fuel consumption.

  As shown in FIG. 2, in the vacuum pump 15, the cylinder portion 17 is in a posture that is long in the substantially vertical direction. Therefore, the built-in piston reciprocates substantially vertically. Then, a reciprocating load that acts to swing the vacuum pump 15 in the vertical direction acts on the vacuum pump 15, and this load causes a moment that attempts to rotate the vacuum pump 15 in the vertical direction about the auxiliary boss portion 19. become. Therefore, if the auxiliary boss portions 19 for fixing the vacuum pump 15 are arranged side by side, a large moment acts on the attachment portion, which may reduce the attachment strength during use. .

  On the other hand, in this embodiment, since the two auxiliary boss portions 19 are arranged in the vertical direction, a large moment does not act on the auxiliary boss portion 19 and the bracket portion 18. No great load is applied to the portion 18. Therefore, the problem of strength reduction does not occur.

  Furthermore, in the present embodiment, the auxiliary boss portion 19 and the main boss portion 13 are connected by the ribs 21, so that when the auxiliary boss portion 19 is apex, a triangular (mountain-shaped) projecting portion 22 is formed. The rigidity of the part to which is fixed is remarkably high. Also in this respect, the mounting strength of the vacuum pump 15 can be improved.

  Further, even if the vacuum pump 15 vibrates, the stress caused by the vibration is dispersed in the overhanging portion 22, so that the stress generated in the overhanging portion 22 can be easily reduced. Therefore, it is possible to prevent distortion of the sealing surface between the front side wall 12a of the front cover 3 and the cylinder block 1. Note that the ribs 21 can be provided only above or below the auxiliary boss portion 19, but if they are provided above and below as in the present embodiment, the rigidity of the overhanging portion 22 is significantly increased, which is preferable. is there.

  By disposing the vacuum pump 15 on the intake side of the engine body as in the present embodiment, it is possible to prevent adverse effects due to heat and contribute to ensuring safety. Further, since the vacuum pump 15 is located behind the front surface of the intake manifold 5, it is possible to prevent the intake manifold 5 from acting as a cover and giving an impact to the vacuum pump 15 in the event of a collision accident. In this respect as well, safety can be secured.

  Although the embodiment of the invention of the present application has been described above, the invention of the present application can be embodied in various forms other than the illustrated embodiment.

  The present invention can be embodied in an internal combustion engine for automobiles. Therefore, it can be used industrially.

1 Cylinder Block 2 Cylinder Head 3 Front Cover 5 Intake Manifold 12a, 12b Side Wall of Front Cover 13 Main Boss 15 Vacuum Pump 16 Drum 17 Cylinder 18 Bracket 19 Auxiliary Boss 20 Vacuum Pump Fastening 21 Rib 22 Overhang 23 groove 24 main bolt

Claims (4)

It is arranged in the engine room provided in the front part of the vehicle body, and has a configuration in which a front cover for covering the timing chain is fixedly stacked on the front surfaces of the cylinder block and the cylinder head.
The front cover is provided with an auxiliary boss portion protruding from the overlapping portion with the cylinder block or the cylinder head, and a vacuum for assisting a brake booster is provided on a rear surface of the auxiliary boss portion that overlaps with the cylinder block or the cylinder head. The pump is fixed,
Internal combustion engine for automobiles. A sealant applied to a superposed surface of the front cover and the cylinder block or the cylinder head at a portion of the rear surface of the auxiliary boss portion of the front cover which is closer to the cylinder block or the cylinder head than the superposed surface with the vacuum pump. Form a groove that can flow
The internal combustion engine for an automobile according to claim 1. It is arranged in the engine room provided in the front part of the vehicle body, and has a configuration in which a front cover for covering the timing chain is fixedly stacked on the front surfaces of the cylinder block and the cylinder head.
The front cover is provided with upper and lower auxiliary boss portions protruding from the overlapping portion with the cylinder block or the cylinder head, and a vacuum pump having a piston that reciprocates substantially vertically is fixed to the upper and lower auxiliary boss portions. Is
Internal combustion engine for automobiles. Main boss portions for fixing the front cover to a cylinder block or a cylinder head are arranged on both upper and lower sides of the auxiliary boss portion, and the auxiliary boss portion and the main boss portion are connected by ribs.
An internal combustion engine for an automobile according to any one of claims 1 to 3.

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