JP5824893B2 - Supercharger for internal combustion engine - Google Patents

Description

  The present invention relates to a supercharging device for an internal combustion engine.

  As a technique for increasing the intake efficiency of a turbocharger, Patent Document 1 describes a technique in which guide vanes (guide vanes) are provided on the upstream side of a compressor that supercharges intake air. The inclination angle of this guide vane can be adjusted by a gear in a gear case provided at the center of the intake passage, and the inclination angle of the guide vane is controlled according to the engine load and the engine speed. ing.

JP 58-167824 A

  By rectifying the intake air flowing into the centrifugal compressor with the guide vanes and adding the swirl component, it is possible to increase the intake efficiency and accelerate the rise of the engine output and torque, particularly in the low speed region where the intake air flow rate is small. However, there is a concern that in the middle and high speed regions where the intake flow rate is large, the ventilation resistance by the guide vanes increases, and conversely the engine output and torque are reduced.

  Further, as described in Patent Document 1, in order to adjust the inclination angle of the guide vanes according to the engine rotational speed or the like, the individual guide vanes are made movable, and the inclination angle is changed and held. A complicated gear mechanism is required, and there are concerns about an increase in the size of the device, an increase in cost, and a decrease in durability and reliability.

  The present invention has been made in view of such circumstances, and can provide both a turning component in a low speed range and a reduction in ventilation resistance in a medium / high speed range while having a simple structure. An object of the present invention is to provide a new supercharging device for an internal combustion engine.

  That is, a supercharging device for an internal combustion engine according to the present invention is provided with a compressor that supercharges intake air and a taper shape that is provided on the upstream side of the compressor and whose inner peripheral surface gradually decreases in diameter toward the downstream side. An intake pipe section and a guide vane that imparts a swirl component to the intake air, and the intake guide unit provided inside the intake pipe section, and the intake air intake section so that a gap between the intake guide unit and the intake pipe section is increased or decreased. And an actuator for driving the guide unit along the longitudinal direction of the passage.

  With the above configuration, in a predetermined low speed range, the intake guide unit is driven and arranged on the downstream side by the actuator, and the tapered intake pipe portion that gradually decreases in diameter toward the downstream side is arranged on the inner side. The gap with the intake guide unit is reduced. Therefore, most of the intake air passes through the intake guide unit including the guide vane, and the rectification of the intake air and the application of the swirling component by the guide vane are promoted. As a result, the increase in the rotation of the compressor is accelerated and the development of the boost is promoted, so that the start of the low-speed torque can be accelerated and the turbo lag can be suppressed / eliminated.

  On the other hand, the intake guide unit is driven and arranged on the upstream side by an actuator in a predetermined middle / high speed range where the engine rotation speed is higher than the low speed range. As a result, the clearance between the inner peripheral surface of the intake pipe section that extends toward the upstream side and the intake guide unit that is placed inside the intake pipe section increases, reducing ventilation resistance and suppressing engine output and torque reduction. can do.

  In addition, by adopting a tapered shape in which the diameter of the intake pipe portion gradually decreases toward the downstream side, the flow velocity can be increased without disturbing the flow of intake air. That is, by using such a tapered intake pipe portion and driving the intake guide unit in the longitudinal direction of the passage, out of the total amount of intake air passing through the intake pipe portion, the flow rate passing through the intake guide unit The ratio of the flow rate through the gap outside the intake guide unit can be adjusted.

  Furthermore, since the entire intake guide unit is linearly driven by the actuator along the longitudinal direction of the passage, the structure of the actuator and the intake guide unit is simplified. In particular, since the intake guide unit including the guide vanes does not require a movable part, for example, a plurality of guide vanes and a nose cone can be integrally formed of a synthetic resin material. In addition, as compared with the case where each guide vane has a movable structure, the number of parts can be greatly reduced, simplified, and reduced in weight, and durability and reliability are also improved.

  As described above, according to the present invention, it is possible to achieve both the provision of the rectification / swirl component by the guide vanes in the low speed range and the reduction of the airflow resistance in the middle / high speed range, though the structure is simple. .

The perspective view which shows the intake pipe part of the supercharging device of the internal combustion engine which concerns on one Example of this invention. The principal part of the supercharging device of the said Example is shown, (A) is sectional drawing in the state which has arrange | positioned the intake guide unit to the most upstream side, (B) is the state in the state which has arrange | positioned the intake guide unit to the most downstream side Sectional drawing. The perspective view which shows a single air intake guide unit. The perspective view which shows the nose cone and guide vane which were integrally molded of the intake guide unit. The perspective view which shows the turbocharger to which the said intake pipe part is attached.

  Hereinafter, the present invention will be described with reference to illustrated embodiments. Referring to FIG. 5, this internal combustion engine is provided with a turbocharger 1. As is well known, the turbocharger 1 is fixed on the same axis as the exhaust turbine 2 driven by exhaust energy and coaxially with the exhaust turbine 2, and rotates integrally with the exhaust turbine 2 to compress the intake air. And a centrifugal scroll compressor 3 for supercharging. An exhaust manifold 4 attached to the side wall on the exhaust side of the internal combustion engine is provided on the upstream side of the exhaust turbine 2. An intake pipe portion 10 to be described later is attached to the attachment flange 5 on the upstream side of the compressor 3 (see FIGS. 1 and 2). The intake air passes through the intake pipe portion 10 from an air cleaner (not shown) and the like, then is supplied to the compressor 3, and passes through an intake outlet pipe or an intake manifold (not shown) attached to the outlet pipe portion 6 of the compressor 3. To the combustion chamber of each cylinder.

  As shown in FIGS. 1 and 2, the intake pipe portion 10 has a cylindrical shape whose both ends are open, and the inner peripheral surface gradually decreases in diameter from the upstream side to the downstream side in the flow direction F of intake air. It has an inclined surface / tapered surface, which makes the intake air flow velocity faster without disturbing the intake air flow. An upstream attachment flange 11 to which an intake duct (not shown) is attached is provided at the upstream end portion of the intake pipe portion 10, and an upstream attachment flange 5 of the compressor 3 is provided at the downstream end portion. A downstream mounting flange 12 is provided which is attached to (FIG. 5). Bolt holes 11A and 12A through which fixing bolts are inserted are formed in the mounting flanges 11 and 12, respectively.

  An intake guide unit 20 that is a main part of the present embodiment is disposed inside the intake pipe portion 10 having a tapered shape. 3 is a perspective view showing the intake guide unit 20 as a single unit, and FIG. 4 is a perspective view showing the nose cone 22 and the guide vane 23 provided inside the intake guide unit 20 with the outer cylinder portion 21 omitted. It is. The intake guide unit 20 includes a cylindrical outer cylinder portion 21, a nose cone 22 arranged concentrically along the central axis (L0) of the outer cylinder portion 21, and the nose cone 22 and the outer cylinder portion. And a plurality of guide vanes 23 that are stretched between the outer cylinder portion 21 and the central axis of the outer cylinder portion 21 along the passage longitudinal direction (passage center line) L0. Has been.

  The nose cone 22 and the guide vane 23 are integrally formed of a synthetic resin material, and the outer peripheral edge of the guide vane 23 is formed of the synthetic resin material (or a metal material such as an aluminum alloy). It is integrally joined to the surface. Thus, the intake guide unit 20 is composed of two parts, and the number of parts is significantly reduced, the weight is reduced, and the cost is reduced.

  The nose cone 22 has a solid conical shape that gradually expands in diameter toward the downstream side (right side in FIG. 2) in the intake flow direction F, and thereby flows downstream while rectifying the intake flow. Accordingly, the intake passage cross-sectional area is gradually reduced to increase the intake air flow velocity. The rear end portion 22A of the nose cone 22 is formed on a smooth curved surface that curves convexly toward the downstream side so as not to disturb the flow.

  The guide vane 23 has a belt-like shape extending while being spirally curved from the upstream end to the downstream end of the outer cylinder portion 21 so as to impart a swirl component to the intake air and enhance the swirl flow velocity. The swirl direction of the intake air provided by the guide vane 23 is appropriately set according to the impeller shape of the centrifugal scroll compressor 3 disposed on the downstream side.

  Such an intake guide unit 20 is supported by the intake pipe portion 10 so as to be movable along the passage longitudinal direction L0 by a support mechanism, and is also provided in the passage longitudinal direction L0 by an electric or hydraulic actuator 25. Is driven and held along. The operation of the actuator 25 is controlled by a control unit 24 (see FIG. 1) having a function of storing and executing various control processes.

  The support mechanism includes a pair of arm portions 26 projecting radially outward from the outer periphery of the front end of the outer cylinder portion 21 along the diametrical direction, and is fixed to each arm portion 26 and extends along the passage longitudinal direction L0. A pair of guide plates 27, and the tip of one arm portion 26 is connected to the tip of the output shaft 25 </ b> A of the actuator 25. A guide portion 28 having a guide surface 29 parallel to the passage longitudinal direction L0 is formed on the outer periphery of the intake pipe portion 10 so that the guide plate 27 extends in the passage longitudinal direction F on the guide surface 29. It is arranged to be slidable along. A slit 30 through which the arm portion 26 passes is formed in the guide portion 28.

  2A shows a state in which the intake guide unit 20 is arranged on the most upstream side (left side in the figure), and FIG. 2B shows the intake guide unit 20 on the most downstream side (right side in the figure). The state of arrangement is shown.

  As shown in the figure, since the inner peripheral surface of the intake pipe portion 10 forms a tapered surface that gradually decreases in diameter toward the downstream side, the actuator 25 moves the intake guide unit 20 along the passage longitudinal direction L0. Along with the driving, the minimum gaps ΔD1 and ΔD2 between the intake pipe portion 10 and the intake guide unit 20, more specifically, the inner peripheral surface of the intake pipe portion 10 and the outside of the intake guide unit 20 opposed thereto. The gaps ΔD1 and ΔD2 between the outer peripheral surface of the downstream end portion of the cylindrical portion 21 increase and decrease. Specifically, as shown in FIG. 2A, the gap ΔD1 increases as the intake guide unit 20 moves upstream, and the gap ΔD2 decreases as the intake guide unit 20 moves downstream.

  In this embodiment, the engine rotational speed is a predetermined low speed range lower than a predetermined value, more specifically, a lower speed side than an intercept point that is an engine rotational speed at which supercharging pressure control starts at full load. In the region before interception, as shown in FIG. 2B, the actuator 25 drives and arranges the intake guide unit 20 on the (most) downstream side to reduce the gap ΔD2. As a result, the ratio and flow rate of the intake air flowing through the outer gap ΔD2 out of the total amount of intake air flowing through the intake pipe portion 10 is suppressed, and most of the intake air flows through the outer cylinder portion 21 of the intake guide unit 20. The swirl component of the intake air flowing into the compressor 3 can be strengthened to increase the swirl flow velocity. As a result, the increase in the rotation of the compressor 3 can be promoted, the increase / rise of the boost pressure can be accelerated, the rise of the low-speed torque can be improved, and the turbo lag can be suppressed / eliminated.

  On the other hand, in the middle and high speed range where the engine speed is higher than the predetermined value, more specifically, in the post-intercept region on the higher speed side than the intercept point, the boost pressure has already increased, so the turning component is strengthened. However, the increase in ventilation resistance when passing through the plurality of guide vanes 23 in the outer cylinder portion 21 may cause a decrease in engine output (maximum output) and torque. Therefore, in this embodiment, in the middle and high speed range after such interception, as shown in FIG. 2A, the actuator 25 drives and arranges the intake guide unit 20 on the (upstream) upstream side, and the above-mentioned The gap ΔD1 is reduced. As a result, of the total amount of intake air flowing through the intake pipe portion 10, the ratio and flow rate of the intake air flowing through the outer circumferential gap ΔD1 increases, while the flow rate of the intake air flowing through the outer cylinder portion 21 of the intake guide unit 20 is suppressed. The As described above, the clearance D1 on the outer peripheral side is increased to secure a sufficient passage area, and the flow rate flowing in the outer cylinder portion 21 is suppressed, thereby suppressing the airflow resistance and improving the maximum output and torque. Can be planned.

  Further, since the entire intake guide unit 20 is linearly driven by the actuator 25 along the longitudinal direction of the passage, the structure of the actuator 25 and the intake guide unit 20 is simplified and the response is excellent. . In particular, since the intake guide unit including guide vanes does not require a movable part, a plurality of guide vanes 23 and nose cones 22 can be integrally formed of a synthetic resin material as in the above embodiment. Thus, as compared with the case where each guide vane has a movable structure, the number of parts can be greatly reduced, simplified, and reduced in weight, and the durability and reliability are greatly improved.

  As described above, the present invention has been described based on the specific embodiments. However, the present invention is not limited to the above-described embodiments, and includes various modifications and changes without departing from the spirit of the present invention. .

  For example, in the above embodiment, the outer cylinder portion 21 has a straight shape with the same outer diameter. However, like the intake pipe portion 10, it may have a tapered shape that gradually decreases in diameter toward the downstream side. In the case of such a tapered shape, more intake air is guided and supplied into the outer cylinder portion 21 than in the case of the straight shape as in the above embodiment. As shown in B), in the low speed range where the intake guide vane 23 is driven and arranged downstream, the airflow resistance is suppressed and the swirl component is further strengthened, but the intake guide vane 23 shown in FIG. In the middle / high speed range where the engine is driven and arranged on the upstream side, the projected cross-sectional area of the outer cylindrical portion 21 of the intake guide vane 23 viewed from the inlet side is enlarged, the ventilation resistance is deteriorated, and the maximum output / torque is reduced. Therefore, when aiming to improve low-speed torque mainly by applying swirl components in the low-speed range, it is preferable to make the outer cylinder part a tapered shape, and when aiming to lower the ventilation resistance mainly in the mid- and high-speed range For this reason, it is preferable to make the outer cylinder part straight as in the above embodiment.

DESCRIPTION OF SYMBOLS 1 ... Turbocharger 3 ... Compressor 10 ... Intake pipe part 20 ... Intake guide unit 21 ... Outer cylinder part 22 ... Nose cone 23 ... Guide vane 25 ... Actuator

Claims (3)

A compressor that supercharges intake air;
An intake pipe portion which is provided on the upstream side of the compressor and has a tapered shape whose diameter gradually decreases as the inner peripheral surface thereof moves toward the downstream side;
Has an intake guide unit provided within the upper Symbol intake pipe portion,
The guide unit includes an outer cylinder portion concentrically arranged with the intake pipe portion, and a guide vane that imparts a swirl component to the intake air flowing through the outer cylinder portion,
Further, as the gap between the inner circumferential surface of the outer peripheral surface and the intake pipe section of the outer tubular portion of the intake guide unit increases or decreases, and characterized by having an actuator for driving along the intake guide unit in the passage longitudinally A supercharging device for an internal combustion engine. In a predetermined low speed range, the intake guide unit is arranged downstream by the actuator so that the gap between the tapered inner peripheral surface of the intake pipe portion and the intake guide unit arranged inside the intake pipe portion becomes small. While letting
2. The internal combustion engine according to claim 1, wherein the intake guide unit is arranged upstream by the actuator so that the gap becomes larger in a predetermined middle / high speed range where the engine rotation speed is higher than the low speed range. Engine supercharger. The intake guide unit has a nozzle cone arranged along the central axis of the outer cylinder portion, and the nozzle cone has a tapered shape in which the outer peripheral surface gradually increases in diameter toward the downstream side. And
The guide vanes, as well as bridged and the nozzle cone and the outer tubular portion, claim 1 or toward the upstream side to the downstream side, characterized in that it forms a strip which extends while curving spirally 2. A supercharging device for an internal combustion engine according to 2 .

Images