JPH05256146A - Mechanical supercharger - Google Patents

Abstract

PURPOSE:To improve the fuel consumption of an engine by providing a compressor housing having an impeller enclosed therein, and a supporting means for supporting one or both of the impeller and the wall part of the compressor housing. CONSTITUTION:The impeller 39 of a supercharger is disposed in a compressor housing 41 and press-fitted to the right end part of an impeller shaft 19. The compressor housing 41 is provided with a spiral volute 45, an air inlet member 47 (wall part) and a diffuser. The inlet member 47 is connected in the axially movable state to the volute 45 by a cylindrical engaging part 59 (supporting means) formed between the inlet member 47 and volute 45 and provided with an O-ring 57 disposed in between. A space S formed between the member 47 and impeller 39 can be changed by moving the member 47. When the supercharging of an engine is unrequired, a controller 67 operates a motor 65 to enlarge the space S. Driving horsepower at the supercharging unrequired time is thus reduced with the connection to the engine left as it is so as to improve the fuel consumption of the engine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical supercharger used for vehicles.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 3-500317 discloses a "mechanical drive type supercharger for an internal combustion engine". This is a centrifugal compressor type supercharger that is rotationally driven by the driving force of the engine.

[0003]

The mechanical supercharger is mechanically connected to the engine and is driven even when supercharging is not required, and the power loss corresponding to that causes poor fuel economy during partial load running of the vehicle. Is becoming To prevent this, an interrupting device such as an electromagnetic clutch may be arranged, and for example, the turbocharger may be disconnected when the engine is rotating at a constant speed. It gets complicated.

Therefore, an object of the present invention is to provide a mechanical supercharger which has a simple structure and can reduce power loss when supercharging is unnecessary.

[0005]

SUMMARY OF THE INVENTION A mechanical supercharger of the present invention is an impeller rotatably driven by a driving force of an engine, a compressor housing having the impeller housed therein, a wall portion of the compressor housing, and an impeller. And a supporting means for supporting one or both of them so that the distance between them can be varied.

[0006]

The impeller is rotationally driven by the driving force of the engine, pressurizes the intake air, and supercharges the engine.

The wider the distance between the impeller and the wall of the compressor housing, the lower the compressor efficiency and the driving horsepower as well as the boost pressure. Therefore, if the interval is widened when supercharging is not required, power loss is reduced and fuel consumption is improved. Also, the boost pressure can be adjusted by adjusting this interval.

The structure in which the wall of the compressor housing and the impeller are variably supported by the supporting means and the space is adjusted is simpler than the structure in which the interrupting device is provided. The control function of supercharging pressure which was not possible is obtained.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described with reference to FIGS. FIG. 1 shows a mechanical supercharger of this embodiment. The left and right directions are the left and right directions in FIG. 1, and members and the like without reference numerals are not shown. As shown in FIG. 1, the mechanical supercharger 1 of this embodiment includes a speed increasing unit 3 and a supercharger 5.

The input shaft 7 of the speed increasing unit 3 is supported by a casing 9 which is inserted through bearings 11 and 13. A pulley is spline-connected to the left end of the input shaft 7 and fixed by a washer 8 and a nut 10. The input shaft 7 is connected to the crankshaft of the engine through a belt transmission mechanism including this pulley, It is constantly driven to rotate by the driving force.

The speed increasing unit 3 is a planetary gear type speed increasing mechanism. The internal gear 15 is integrally formed at the right end of the input shaft 7, and the sun gear 17 is at the left end of the impeller shaft 19 of the supercharger 5. Has been formed. The pinion gear 21 is supported by a pinion shaft 25 via a bearing 23, and the pinion shaft 25 is a boss portion 27 of the casing 9.
Supported by. The driving force from the engine is increased by the speed increasing unit 3 to rotate the impeller shaft 19 at high speed.
The impeller shaft 19 is supported by a bearing 31 arranged on the boss portion 27 via an oil film damper 29. Oil plug 3 inside the casing 9
Lubricating oil is supplied from 3, and oil leakage is prevented by the seals 35 and 37.

The impeller 39 of the supercharger 5 is arranged in a compressor housing 41 and is press fitted into the right end portion of the impeller shaft 19. Further, a fall prevention member 43 for the impeller 39 is swaged at the right end of the impeller shaft 19. As shown in FIG. 2, the compressor housing 41 includes a volute 45, a suction port member 47 (wall portion) for air, and a diffuser 49. Volute 4
5 is a connecting member 53 engaged with the circumferential groove 51 of the casing 9.
It is attached to the casing 9 via a bolt 55 and a bolt 55.

The suction port member 47 is connected to the volute 45 so as to be movable in the axial direction by a cylindrical engaging portion 59 (supporting means) which is formed between the volute 45 and an O-ring 57 and is arranged between them. By doing so, the distance S from the impeller 39 can be changed. The engaging portion 59 is provided with a stopper portion 61 for determining the minimum value of the interval S and for avoiding contact between the suction port member 47 and the impeller 39.

The lever portion 63 of the suction port member 47 is connected to a motor 65 via a mechanism that is composed of, for example, a worm gear and a ball screw, and converts a rotational force into a thrust force. The motor 65 operates the suction port member 47 to move. Increase or decrease the interval S. The controller 67 operates the motor 65 to widen the interval S when supercharging of the engine is unnecessary. In this embodiment, the interval S is maximized when the vehicle speed signal 69 is received at a constant vehicle speed and when the throttle opening signal 70 is received at a set opening.

FIG. 4 shows the case where the space S is 0.5 mm as in the conventional case (corresponding to the conventional example), and FIG. 3 shows the space S of 2.
It is a graph which shows the characteristic of supercharger 5 when it expands to 0 mm. These graphs show changes in the pressure ratio and the air flow rate when the slots are opened while the engine load is changed and the rotational speed of the supercharger 5 is held in five stages from 40,000 rpm to 80,000 rpm. The driving horsepower (KW) at the time when the throttle is fully opened and the pressure ratio becomes approximately 1 is entered in the graph of each rotational speed.

From the comparison of the driving horsepowers shown in FIG. 3 and FIG. 4, it can be seen that when the interval S is widened, the efficiency of the compressor is lowered and the driving horsepower is reduced, and that this effect is greater as the rotational speed is higher. .. In this way, the power loss of the engine can be reduced and the fuel consumption can be improved without disconnecting the supercharger 5 when supercharging is unnecessary. It is also possible to control the boost pressure by finely adjusting the interval S. Since the connecting / disconnecting device for disconnecting the supercharger 5 from the engine is not used, the structure is simple and lightweight.

The impeller may be supported by the support means so as to be movable in the axial direction, and the interval S may be adjusted by moving the impeller.

[0018]

In the mechanical supercharger of the present invention, one or both of the wall portion of the compressor housing and the impeller are variably supported by the supporting means, so that the interval is widened when supercharging is not required. By doing so, it is possible to reduce driving horsepower and improve fuel efficiency while the engine is still connected. Further, the supercharging pressure can be controlled by adjusting the interval. It has a simple structure and is lightweight, as it does not use an intermittent mechanism with the engine.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a graph showing characteristics of the example when the spacing S is widened.

FIG. 4 is a graph showing characteristics of the example when the interval S is narrowed.

[Explanation of symbols]

 1 Mechanical Supercharger 5 Supercharger 39 Impeller 41 Compressor Housing 47 Intake Port Member (Wall) 59 Engagement Part (Supporting Means)

Claims (1)

[Claims] 1. An impeller rotatably driven by a driving force of an engine, a compressor housing having the impeller housed therein, and a support means for supporting one or both of a wall portion of the compressor housing and the impeller with a variable distance therebetween. And a centrifugal compressor type mechanical supercharger.