JPS6040728A - Engine with supercharger - Google Patents

Abstract

PURPOSE:To improve transient responsiveness ever so better, by making a high- speed type supercharger operate in a low-speed range to some extent and, in turn, fully operating the high-speed supercharger at once by means of a back- pressure selector with shifting to the high-speed range, in the case where double supercharging takes place with both low- and high-speed superchargers. CONSTITUTION:In time of low-speed operation on an engine 1, since back pressure in the exhaust gas is small enough, a waste gate valve 8 of a back-pressure selector 10 being set up in an exhaust passage is closed. In consequence, the whole lot of exhaust gases out of the engine 1 flows in a turbine 5b of a low- speed type supercharger 5 set up in a suction passage 3 and performs its scavenging action. At this time, the exhaust gas after driving the supercharger 5 flows in a turbine 4b of a high-speed type supercharger 4 through an exhaust passage 7 and gets ready for supercharging. And, when the engine 1 reaches the specified engine speed and the above valve 8 is opened by back pressure in the exhaust gas, a part of the exhaust gas directly flows in the turbine 4b by way of a bypass passage 9 and exhaust passage 7. With this constitution, the high-speed supercharger 4 performs its operation at once.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a supercharged engine for a vehicle, and particularly to an engine that includes a low speed type or a high speed type supercharger and performs two-stage supercharging.

When supercharging a carrot using an exhaust turbo supercharger that uses exhaust energy, one turbocharger has a trade-off between low-speed response and high-speed output increase. We are trying to match the supercharger to the engine.

Therefore, in the case of such matching, since the gear/V ratio is selected based on the transient response during acceleration (marginal driving force), it is not possible to select a high gear A7 mode that can improve light fuel resistance. There is.

Therefore, conventionally, for example, as shown in Japanese Unexamined Patent Publication No. 55-123313, first stage and second stage superchargers are arranged in series,
A two-stage supercharger has been proposed in J() that uses these two stages of supercharger depending on the rotation speed. However, according to this prior art, the second stage supercharger 1] The gas that drove the engine is exhausted from the exhaust pipe, and the first stage supercharger is not functioning as an exhaust turbo at all at this time.Then, when the rotation speed is high, the first stage Supercharging 1 Many exhaust gases are being used to drive the 1
Since there is a 1p7 starting from 711, the transient distortion during supercharging by this first stage supercharger is large.

The present invention is as follows: 1. T In view of the problems with two-stage supercharging according to the conventional technology, the system avoids the IJI turbo effect to the extent that a high-speed supercharger would do at low speeds, and automatically shifts to a state where supercharging is possible as the rotational speed increases. The object of the present invention is to provide a supercharged engine for this high-speed supercharger in which the transient response of the filtration feed 115 is improved.

For this purpose, the present invention connects the exhaust passage from the low-speed supercharger and the bypass passage of the exhaust bypass type back pressure switching device installed in the low-speed supercharger to the high-speed supercharger. What happens when the drive of a low-speed supercharger is regulated by a back pressure switching device? 333I! The purpose of this is to enable immediate supercharging of type turbochargers.

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings. In Figure 1, there is J5, where 1 is the engine body and 2 is ENO? The cleaner 3 is an intake passage, and this intake passage 3
From the upstream side, the compressor 4a of the second-stage high-speed supercharger 4, and the compressor 5 of the first-stage low-speed supercharger 5.
a are arranged in series. In addition, in the exhaust system, an exhaust passage 6 from the engine body 1 is provided.
The exhaust passages 7 from the turbine 5b are connected in six rows so as to flow into the turbine i4b of the high-speed supercharger 4. Then, a valve 8 is connected to the exhaust passage 6 to the turbine 5b of the low-speed supercharging [5] to the sea urination gate 1.
A bypass device 10 is installed, and a bypass passage 9 of this device 10 joins the exhaust passage 7. Furthermore, a muffler 12 is installed in the exhaust passage 11 from the turbine 4 () of the 11-speed supercharger 4.
etc. were installed and became popular (111 bold.The same number 13 is a pressurized carburetor, 141J is a stage immediately upstream of it) L Achigamba.

Because of this configuration, the back pressure of exhaust gas is small in the low speed range when the
Since the engine is closed, all of the exhaust gas from the engine body 1 is a low-speed supercharger 4j! The second fuel is introduced into the turbine 5b of No. 5 to perform a supercharging effect, thereby obtaining the characteristics shown by the broken line a of No. 1. On the other hand, at this time, the exhaust gas after driving the supercharger a5 is introduced into the turbine 4b of the high-speed supercharger 4 through the JJL air passage 7, so the supercharger 4 does not substantially supercharge. The engine is rotated to such an extent that it prepares for supercharging. Then, when the specified engine rotation speed is reached,
When the Uniist gate valve 8 opens due to the back pressure of the ul gas, a part of the exhaust gas from the 17th engine body is bypassed! 89. It is directly introduced into the turbine 4b of the high-speed supercharger llI4 via the exhaust passage 7. Therefore, since the high-speed supercharger 4 is already in the quasi-1# state of supercharging, when exhaust gas is directly introduced from the engine by part 8 of the above waste gas, it immediately starts normal driving and is effectively In this case, the supercharging starts at 1111, and the characteristics in this case are as shown by the broken line in FIG. The engine characteristics are as shown by the solid line C in FIG.

According to the present invention, in a two-stage supercharging system in which low-speed and high-speed superchargers 4 and 5 are arranged in series, the low-speed supercharger 5 provides supercharging. When the high-speed supercharger 4 is being controlled, the high-speed supercharger 4 is also driven to rotate (so much so) that when the drive of the low-speed supercharger 5 is regulated, the high-speed supercharger 4 immediately starts supercharging. 〃■ Since it starts, J3 can be supercharged without delay during the transition period from low speed range to high speed range. Further, since the transition from a low-speed type to a high-speed type supercharger is automatically performed by the back pressure switching device 1, the structure is simple.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an embodiment of a supercharger (=t engine) according to the present invention, and Fig. 2 is a JtQ diagram showing supercharging characteristics. 1... Engine body, 3... Intake passage, 4...'
f 4-speed supercharger, 5...low-speed supercharger, e, 7
, 11... Exhaust passage, 8... Waste gate, 9
... Bypass passage, 10... Back pressure switching device. Special W [Applicant Shige Tomigami Kuwa Stock Co., Ltd. Agent Patent Attorney Kobashi (G Storage Ben Soku) - Susumu Murai

Claims (1)

[Claims] In the intake system of the engine body, the high-speed supercharger and low-speed supercharger combiner 1 are arranged in a row from the upstream side, and the 111 air system of the engine body is connected to the a3 from the low-speed supercharger. Filtration feeder 4 characterized in that an exhaust passage and a bypass passage equipped with back pressure switching are both connected to the high-speed supercharger.
=J engine.