JP6894316B2 - Internal combustion engine - Google Patents

Description

The present invention relates to an internal combustion engine in which a negative pressure is taken out by an ejector device using an intake air flow, and is particularly suitable for an internal combustion engine of a vehicle equipped with a brake booster driven by a negative pressure. There is.

The brakes of the vehicle are driven by the flood control that is pumped from the master cylinder, but since the required pressure cannot be obtained only by the pedal depression force, the pedal depression force is amplified by the brake booster and transmitted to the master cylinder. There is. In the brake booster, the piston is generally driven by a negative pressure, and intake air is used as a negative pressure source.

However, in recent years, it has become difficult for vehicles in recent years to directly extract negative pressure from the intake system due to supercharging or leaning. Therefore, it is considered to take out the negative pressure by passing the intake air through the ejector chamber, and an example thereof is disclosed in Patent Document 1.

Japanese Unexamined Patent Publication No. 2010-1879

Patent Document 1 extracts negative pressure by utilizing the flow of intake air, and can extract negative pressure even if the intake air is positive pressure, so that the drive of the brake booster can be ensured, but a dedicated ejector can be used. Since the device must be prepared, there is a problem that the weight increases and it becomes a negative factor for fuel efficiency, and it takes time and effort to design because it is necessary to adjust with other members to select the installation location of the ejector device. There was a problem.

If the ejector device is provided at a location away from the intake system, the pipelines (pipes, tubes) through which the intake air flows become longer, so that the problems of weight increase and cost increase become more prominent. Further, if the ejector device and the intake system are connected by a pipe (pipeline), there is a concern that the ejector effect may be reduced due to pressure loss.

The present invention has been made in view of this situation, and while it is common with Patent Document 1 to take out negative pressure by utilizing the flow of intake air, it is not provided in an improved form such as making it compact. Is to be.

The invention of the present application includes various configurations, and a typical example thereof is specified by a claim. In the invention of claim 1,
"Intake system members with multiple branch pipes arranged side by side on the outer surface of the tank,
A lid member that partially surrounds the intake system member from the outside to form a closed space outside the intake system member is provided.
The lid member is arranged so as to cover the one branch pipe and the portions on both sides sandwiching the branch pipe, and the space is a throttle portion located at a portion between the lid member and the one branch pipe. It has a first expansion portion located on one side of the throttle portion and a second expansion portion located on the other side of the throttle portion.
A first opening is formed in a portion of the lid member that covers the first expansion portion, and a second opening is formed in a portion of the lid member that covers the throttle portion.
A third opening for communicating the tank and the second expansion portion is formed at the portion of the tank at the second expansion portion. "
It is configured as.

The invention of claim 2 is claimed in claim 1.
"The intake system member has three or more of the branch pipes, and valleys are formed on both sides of the one branch pipe.
The lid member is arranged so as to partially cross the one branch pipe and the valleys on both sides thereof, and the throttle portion is formed between the top surface portion of the one branch pipe and the lid member. The extension is formed at the valley. "
It is configured as.

The invention of claim 3 is claimed in claim 1 or 2.
"The intake system member is formed hollow by joining a plurality of shell-shaped members."
It is configured as.

The negative pressure taken out from the space ( ejector chamber ) can be used in various ways. For example, as in Patent Document 1, it can be used as a drive source for a brake booster, and can also be used for suction of a fuel canister, suction of blow-by gas, and the like.

In the present invention, since the intake system member is also used as a part of the ejector device, it can be made compact and the weight can be reduced. In addition, since the intake air taken into the space ( ejector chamber ) returns directly to the intake system from the intake outlet (third opening) provided in the intake system member (tank) , pipes and hoses for returning the intake air to the intake system. The above-mentioned intake system member is also used as a part of the ejector device, so that the weight can be suppressed and the fuel efficiency can be improved.

Further, since the ejector device is integrated with the intake system member, it does not affect the layout of other members at all, and therefore, it is possible to save the trouble of designing the arrangement position. Further, since the ejector chamber is integrated with the intake system member, the installation space is small and the ejector chamber can be arranged without being affected by other members.

Further, since the intake air returns directly from the intake outlet to the inside of the intake system member, the pressure loss can be remarkably reduced and a high ejector effect can be obtained. As a result, the extraction of negative pressure can be ensured.

Depending on the type of internal combustion engine, an ejector device may not be required, such as when the internal combustion engine does not have a supercharger. In this case, if the intake system members are prepared according to the type of the internal combustion engine, there is a problem that it takes time and effort for manufacturing and time and effort for storage and management.

On the other hand, if the configuration of the embodiment is adopted, if the ejector device is not required, it is sufficient to connect the joint to the third opening (intake air outlet) without attaching the lid member. Therefore, the intake system member uses the ejector device. It can be shared between the case where it is provided and the case where it is not provided. Therefore, the intake system members can be shared by internal combustion engines having different specifications, which can contribute to cost reduction as a whole.

In addition, another negative pressure outlet is provided at a portion of the lid member located on the side opposite to the first opening ( intake inlet ) (located on the side of the third opening ( intake outlet )) across the throttle portion. In the case of an internal combustion engine that does not require an ejector chamber, the first opening ( intake inlet) and the second opening ( ejector type negative pressure outlet ) can be closed with a plug. If the other negative pressure outlet is provided in this way, the ejector function can be selectively used according to the operating state of the engine, and the value in use can be further improved.

Although various structures can be adopted for the ejector chamber, in the present invention , the narrowed portion of the ejector chamber can be formed by utilizing the rounded profile of the branch pipe. Therefore, it is possible to prevent the intake system member from becoming thick and further promote compactness and weight reduction.

It is a side view (the side view seen from the lateral direction orthogonal to the cam axis) of the surge tank integrated intake manifold to which the present invention was applied (the lid member is shown by the alternate long and short dash line). FIG. 2 is a sectional view taken along line II-II of FIG. (A) is an enlarged view of a main part of FIG. 1 with a lid member attached, and (B) is a sectional view taken along line BB of (A). It is a conceptual diagram when a negative pressure is applied to the drive source of a brake booster. It is a figure which shows the correspondence when the ejector function is unnecessary. It is a figure which shows another example of an ejector room. It is a figure which shows another example of an ejector room.

(1). Configuration of First Embodiment Next, an embodiment of the present invention will be described with reference to the drawings. First, the first embodiment shown in FIGS. 1 to 3 will be described. This embodiment is applied to the surge tank integrated intake manifold 1.

The internal combustion engine of the present embodiment is for a vehicle and has four cylinders. Therefore, the surge tank integrated intake manifold 1 includes four branch pipes 2a to 2d of the first to fourth branches and one tank 3 in which they communicate with each other. It has. A throttle body fastening portion 4 is integrally provided at one end of the tank 3 on the outer side of the first branch pipe 2a, and the throttle valve 5 is fixed to the throttle body fastening portion 4. The portion between the adjacent branch pipes 2a to 2d is a valley portion 6.

As can be understood from FIG. 2, the surge tank integrated intake manifold 1 has a shape like an inflated hot water bottle as a whole, and each branch pipe 2a to 2d goes downward from the tank 3 and then to the front. The end portion 7 is substantially horizontal, rotating around in the order of top and back. The end portion 7 is connected to the intake port 9 of the cylinder head 8.

In the following, the front-back, left-right, and up-down directions are used to specify the direction, but the left-right direction is the alignment direction of the branch pipes 2a to 2d (the axial direction of the cam axis), and the front-back direction is orthogonal to the cam axis and the cylinder axis. The horizontal direction and the vertical direction are defined as the vertical direction (to be exact, the cylinder axis direction) (these directions assume a vertical engine with the cylinder in the vertical position).

As shown in FIG. 2, the surge tank integrated intake manifold 1 is formed in a hollow structure by the first to third shell-shaped members 10, 11 and 12 which are welded in layers in the front-rear direction. Three members 10, 11 and 12 are joined at their edges.
It is formed in a state.

As shown in FIG. 3A, the branch pipes 2a to 2d extend upward with a wide interval. Therefore, in the upper part, the valley portion 6 has a certain width. Then, the left and right longitudinal lid members 13 are welded to the front surface (outer surface) of the surge tank integrated intake manifold 1 so as to cover the second branch pipe 2b and the valleys 6 on both the left and right sides thereof. An ejector chamber (space) 14 is formed between the member 13 and the surge tank integrated intake manifold 1.

As shown in FIG. 3B, the front surface of the lid member 13 is substantially flat, and the left and right wall portions 13a are in contact with the valley portion 6 of the surge tank integrated intake manifold 1 and welded. Therefore, the portion between the front surface (top surface) of the second branch pipe 2b and the lid member 13 is the squeezed portion 15 having a small cross-sectional area. More precisely, the left and right side portions (the portions of the valley portion 6) sandwiching the throttle portion 15 are the expansion portions 16 and 17 having a larger volume than the throttle portion 15. For convenience, the expansion portion on the side closer to the first branch pipe 2a is referred to as the first expansion portion 16, and the expansion portion on the side closer to the third branch pipe 2c is referred to as the second expansion portion 17.

Of the lid member 13, the throttle portion 15 is provided with a tubular first negative pressure outlet 18 (second opening), and the portion of the lid member 13 corresponding to the first expansion portion 16 is provided. Is provided with a tubular intake inlet 19 (first opening) , and further, a tubular second negative pressure outlet 20 is provided at a portion of the lid member 13 corresponding to the second expansion portion 17. .. Then, an intake outlet (third opening ) 21 for communicating the ejector chamber 14 and the tank 3 is opened in the valley portion of the second expansion portion 17 (in FIG. 2, the intake outlet 21 is drawn by a chain line. The position of is displayed.). The intake inlet 19, the intake outlet 21, and the second negative pressure take-out port 20 can be set to have a left-right relationship opposite to that shown in the figure.

The intake inlet 19 is connected to the upstream side of the intake system with respect to the throttle valve 5. Therefore, the intake air flows through the ejector chamber 14 in the order of the first expansion portion 16 → the throttle portion 15 → the second expansion portion 17, and is released from the intake outlet 21 to the inside of the tank 3, but the first negative pressure outlet 18 Since the opening is toward the throttle portion 15, a negative pressure for sucking air from the outside to the inside is generated in the first negative pressure outlet 18 due to the ejector effect. Various members can be operated by utilizing this negative pressure. In FIG. 2, the black arrow indicates the intake flow direction, and the white arrow indicates the negative pressure suction direction.

(2). Example of application to a brake device FIG. 4 shows an example in which the ejector device of the above-described embodiment is applied to drive a brake booster. This point will be described.

The vehicle is provided with a brake pedal 24 that the driver steps on with his / her foot, and a brake rod 25 that moves back and forth in conjunction with the brake pedal 24 is connected to the brake pedal 24. The forward force of the brake rod 25 is amplified by the brake booster 26.

The brake booster 26 includes an amplification chamber 27 and a control chamber 28 through which the brake rod 25 penetrates. A power piston 29 is slidably fitted in the amplification chamber 27, and a control valve plunger 30 is provided in the control chamber 28. It fits freely on the slide.

The tip of the brake rod 25 is in contact with the main piston 32 built in the master cylinder 31. The master cylinder 31 and the hydraulically driven pad device 33 are connected by a hydraulic line 34, and when the main piston 32 advances, the flood control operates on the hydraulically driven pad device 33 and the wheels W are braked.

The amplification chamber 27 and the control chamber 28 are connected to the first negative pressure take-out port 18 of the lid member 13 via the first negative pressure introduction passage 35, and the amplification chamber 27 and the control chamber 28 are second negative. It is also connected to the second negative pressure outlet 20 of the lid member 13 via the pressure introduction passage 36. Check valves 37 for preventing backflow are inserted in both introduction passages 35 and 36.

The intake inlet 19 of the lid member 13 is connected to the intake system on the upstream side of the throttle valve 5 via the pressure feed passage 38, and is connected to the pressure feed passage 38 by an ECU (engine control unit, not shown). A controlled control valve 39 is provided. The control valve 39 switches between taking out the negative pressure by the ejector device and taking out the direct negative pressure by the second negative pressure take-out port 20 in relation to the pressure sensor provided in the intake system, and controls the flow rate. , It is possible to control the amount of negative pressure taken out from both. That is, while mainly taking out the negative pressure from the second negative pressure take-out port 20, the shortage can be supplemented by taking out from the first negative pressure take-out port 18 (and vice versa).

Since the exhaust device is formed by welding the lid member 13 to the surge tank integrated intake manifold 1, it is compact and does not require the trouble of mounting. Further, since the intake air discharged from the ejector chamber 14 returns from the intake outlet 21 to the tank 3, a hose is not required and the weight and cost can be reduced accordingly, and pressure loss can be eliminated, which can contribute to the improvement of the ejector effect. ..

Further, in the embodiment, since the throttle portion 15 is formed by using the curved cross-sectional shape of the second branch pipe 2b, no special processing is required for the surge tank integrated intake manifold 1, and the manufacturing cost is suppressed accordingly. can do. In FIG. 4, reference numeral 40 indicates an air cleaner, and reference numeral 41 indicates an engine body.

(3). Other Embodiments Next, usage examples and other examples shown in FIGS. 5 to 7 will be described. FIG. 5A shows a response when the ejector function is not required in the first embodiment. As a response in this case, the first negative pressure outlet 18 and the intake inlet 19 are plugged 42. It's blocking.

In FIG. 5B, the surge tank integrated intake manifold 1 can be used in both a mode in which the lid member 13 is attached and a mode in which the lid member 13 is not attached. The joint 43 for connecting the hose is fitted and attached by forced fitting or the like. The joint 43 may be welded to the valley portion 6 of the surge tank integrated intake manifold 1.

In the example shown in FIG. 6, a protrusion 44 is formed between the branch pipe 2 and the lid member 13 in order to increase the degree of constriction of the throttle portion 15. That is, in order to increase the change in the distance between the lid member 13 and the branch pipe 2, the projecting portions 44 facing each other are formed.

On the other hand, in FIG. 7, the degree of drawing of the drawing portion 15 is increased by narrowing the width of the passage between the branch pipe 2 and the lid member 13. In these aspects of FIGS. 6 and 7, it can be said that since the flow velocity of the intake air at the throttle portion 15 becomes high, the ejector effect can be enhanced and a strong negative pressure can be formed.

The invention of the present application can be embodied in various ways other than the above-described embodiments. For example, the exhaust chamber does not necessarily have to be formed in the branch pipe of the intake manifold. For example, when the surge tank and the intake manifold are separated, it can be provided on the outer surface of the surge tank. As already mentioned, the negative pressure can be used for various purposes.

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

1 Surge tank integrated intake manifold 2, 2a to 2d Branch pipe 3 Tank 4 Throttle body 5 Throttle valve 6 Tanibe
10, 11, 12 Shell-shaped member 13 Cover member constituting the ejector device 14 Ejector chamber (space)
15 Aperture part 16 1st expansion part 17 2nd expansion part 18 1st negative pressure outlet (2nd opening)
19 Intake inlet (first opening)
20 2nd negative pressure outlet 21 Intake outlet ( 3rd opening )
24 Brake pedal 26 Brake booster 39 Flow control valve

Claims (3)

An intake system member with multiple branch pipes arranged side by side on the outer surface of the tank,
A lid member that partially surrounds the intake system member from the outside to form a closed space outside the intake system member is provided.
The lid member is arranged so as to cover the one branch pipe and the portions on both sides sandwiching the branch pipe, and the space is a throttle portion located at a portion between the lid member and the one branch pipe. It has a first expansion portion located on one side of the throttle portion and a second expansion portion located on the other side of the throttle portion.
A first opening is formed in a portion of the lid member that covers the first expansion portion, and a second opening is formed in a portion of the lid member that covers the throttle portion.
A third opening for communicating the tank and the second expansion portion is formed at the portion of the tank at the second expansion portion.
Internal combustion engine. The intake system member has three or more branch pipes, and valleys are formed on both sides of the one branch pipe.
The lid member is arranged so as to partially cross the one branch pipe and the valleys on both sides thereof, and the throttle portion is formed between the top surface portion of the one branch pipe and the lid member. It is formed, and the expansion portion is formed at the portion of the valley portion.
The internal combustion engine according to claim 1. The intake system member is formed hollow by joining a plurality of shell-shaped members.
The internal combustion engine according to claim 1 or 2.

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