JPS63105233A - Turbo-compound engine - Google Patents

Abstract

PURPOSE:To avoid a loss from operating a power turbine within low-to-medium speed ranges by causing a by-pass valve to open and close in relation to the hydraulic pressure of the lubricating oil for an engine which is supplied to a liquid clutch. CONSTITUTION:The inlet oil-pressure of the hydraulic oil which is supplied from an oil gallery for an engine to the housing of a liquid clutch 16 is detected by an oil pressure sensor 37, while the outlet oil-pressure at the liquid clutch 16 by another oil pressure sensor 38. If the inlet oil-pressure is more than a fixed value (approx. 3kg/cm<2>), a by-pass valve 10 is caused to close. If the outlet oil-pressure is not more than a fixed value (approx. 0.5kg/cm<2>), the by- pass valve 10 is caused to open.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a turbo compound engine.

[Prior Art] In a turbo compound engine, a turbo supercharger is connected to the exhaust pipe of an internal combustion engine, and this performs intake supercharging.
A recovery turbine is connected to the rear stage of the turbocharger, and this absorbed power is transmitted to the engine crankshaft. By the way, in a turbo compound engine, the energy recovery effect of the power turbine is demonstrated in the engine's full load high speed range, and as shown by the broken line in Figure 2, the back pressure increases due to the power turbine in the middle and low speed range of the engine. Conversely, the shaft output of the engine may decrease due to this.

Therefore, in the method disclosed in Japanese Utility Model Application Publication No. 60-157941, a bypass valve provided in the middle of the pipe connecting the turbo supercharger and the recovery turbine is closed only when the accelerator pedal is depressed to exhaust the air to the recovery turbine. When the accelerator pedal is released, the bypass valve opens to release the exhaust gas from the turbocharger directly to the outside. This results in
This eliminates the waste of driving the recovery turbine in no-load operation with low exhaust energy.

[Problems to be Solved by the Invention] The purpose of the present invention is to focus on the fact that the oil pressure of the engine's lubricating oil, which is the hydraulic oil of the fluid clutch, is approximately proportional to the rotational speed of the engine, and to An object of the present invention is to provide a turbo compound engine that controls a bypass valve in relation to oil pressure.

[Means for Solving the Problem] In order to achieve the above object, the configuration of the present invention includes a bypass valve provided between a turbocharger and a power turbine connected downstream of the turbocharger, and a and control means for opening and closing the bypass valve in relation to the oil pressure of the lubricating oil of the engine supplied to the fluid clutch that transmits the oil pressure to the crankshaft of the engine.

[Operation] Since the inlet oil pressure of the lubricating oil sent from the oil gear gallery of the engine to the fluid clutch is approximately proportional to the engine rotational speed, when the inlet oil pressure exceeds a predetermined value in the high speed range of the engine, the bypass valve is closed by the 7-cut unit. Exhaust gas is introduced from the turbocharger to the power turbine, and the power turbine is driven.

On the other hand, in the middle and low speed range of the engine, the inlet oil pressure is below a predetermined value, so the bypass valve is opened. The exhaust gas from the turbocharger is discharged to the outside and the power turbine is not driven.

This prevents the shaft output from decreasing due to driving the power turbine in the middle and low speed range of the engine.

Even in the high-speed range of the engine, if the outlet oil pressure of the fluid clutch becomes abnormally low, the bypass valve is opened and drive of the power turbine is stopped, thereby preventing overrunning of the power turbine due to malfunction of the fluid clutch.

[Embodiment of the Invention] As shown in FIG. 1, an exhaust pipe 4 connected to an exhaust manifold 3 of an engine 2 is connected to an inlet of a turbine 8 of a turbocharger 5, and this outlet is connected to an inlet of a turbine 8 of a turbocharger 5 through a connecting pipe 9. It is connected to the inlet of the power turbine 12.

The outlet of this power turbine 12 is connected to an exhaust pipe 26 and opened to the outside through a muffler. In the turbocharger 5, the impeller of the turbine 8 and the impeller of the proar 6 are connected by a shaft 7, and intake air is pressurized by the proar and is supplied to the engine 2.

The shaft 13 of the power turbine 12 is coupled to the sun gear of the planetary gear reducer 14, while the shaft 15 of the ring gear is coupled to the input side of the fluid clutch 16.

The output side of the fluid clutch 16 is connected to a reducer 18 via a shaft 17.
The output gear 24 is connected to the crankshaft 19 of the engine 2.

The outlet of the turbine 8 of the turbocharger 5 and the power turbine 1
A bypass valve 10 is provided in the middle of the connecting pipe 9 to the inlet of the turbine 2, and when this valve is opened, the outlet side of the turbine 8 is connected to the bypass pipe 2.
0, the exhaust gas is directly discharged to the outside, and is not sent to the power turbine 12.

The bypass valve 10 is closed when the inlet oil pressure of the hydraulic oil of the fluid clutch 16 is higher than a predetermined value. Preferably, the bypass valve 10 is opened when the outlet oil pressure of the hydraulic oil of the fluid clutch 16 is abnormally reduced.

In the illustrated embodiment, lubricating oil is supplied to the power turbine 12 as hydraulic oil from an oil gear gallery of the engine. The hydraulic oil of the fluid clutch 16 is returned to the oil pan 40 of the engine via the check valve 39. An oil pressure sensor 37 is provided on the inlet side of the housing of the fluid clutch 16, and an oil pressure sensor 38 is provided on the outlet side.

Then, the signals from the oil pressure sensors 37 and 38 are input to the electronic IT (IT) III device 36 including a microcomputer, and an output signal based on this input signal operates an actuator (for example, an N-magnetic actuator).
is opened and closed.

However, as shown in FIG. 3, instead of the oil pressure sensors 37 and 38, pressure switches 37a and 38a are connected in series,
In addition, it may be inserted and connected to the energizing circuit of a solenoid valve as the bypass valve 10.

Next, the operation of the turbo compound engine according to the present invention will be explained. The discharge pressure of the oil pump that lubricates the engine 2 is approximately proportional to the engine rotational speed as shown in FIG. Accordingly, the outlet oil pressure of the fluid clutch 16 is detected by the oil pressure sensor 38 and input to the electronic 111tll device 36, respectively. Then, the inlet oil pressure reaches a predetermined value pH 3.
(e.g., 3kO1012), the electronic control t[l
Bypass valve 10 is closed by a signal from WI 36.

Furthermore, although the outlet oil pressure is higher than atmospheric pressure due to the action of the check valve 39, it is kept at a predetermined value (for example, 0.5k (J/Cl).
112), the bypass valve 10 is opened by a signal from the electronic control 1111t36.

If the check valve 39 malfunctions, the hydraulic circuit connecting from the engine's oil gear to the inlet of the fluid clutch 16 is blocked, or oil leaks from the casing of the fluid clutch 16, the oil pressure inside the fluid clutch 16 will drop and the torque will decrease. is no longer transmitted to the output shaft.

At this time, the power turbine 12 enters a low load operating state, and the rotational speed increases according to the exhaust gas)ffffi, causing overrunning.

In such a case, the outlet oil pressure of the fluid clutch 16 (upstream of the check valve 39) becomes less than a predetermined value, so the bypass valve 10 is opened and exhaust gas is no longer introduced into the power turbine 12. overrunning is prevented.

FIG. 4 shows a flowchart of the above-mentioned 1lltll program, in which 911 to p14 indicate each step. p
At ll, it is determined whether the inlet oil pressure of the fluid clutch 16 is larger than a predetermined value p1, and if the inlet oil pressure is smaller than the predetermined value p1, the bypass valve 10 is opened at p14 to stop driving the power turbine 12. .

On the other hand, if the inlet oil pressure at pll is greater than the predetermined value p1, the outlet oil pressure of the fluid clutch 16 is set to the predetermined value p12 at p12.
It is determined whether the value is smaller than 2 or not. The outlet oil pressure is specified (i
If it is larger than ap2, the bypass valve 10 is activated at p14.
open. On the other hand, if the outlet oil pressure is smaller than the predetermined value fiip2, the bypass valve 10 is closed at p13 and the power turbine 12 is driven.

Effects of CR Light As described above, the present invention is directed to a system that is arranged between a turbo Ia machine and a tower turbine in relation to the inlet hydraulic pressure of the hydraulic oil of the fluid clutch that transmits the power of the power turbine to the crankshaft of the engine. Since the inlet oil pressure changes almost in proportion to the engine speed, the bypass valve is closed in the high-speed range of the engine and the power turbine is activated, reducing exhaust energy. While the power is effectively recovered, the bypass valve is opened in the middle and low speed range of the engine and the power turbine is not driven, thereby avoiding losses caused by driving the power turbine in the middle and low speed range.

Furthermore, by activating the bypass valve in relation to the inlet oil pressure and outlet oil pressure of the fluid clutch, it is possible to prevent overrunning of the power turbine due to failure of the fluid clutch.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of the turbo compound RrjA according to the present invention, Fig. 2 is a miniature diagram showing the relationship between the engine speed and the inlet oil pressure of the fluid clutch, and Fig. 3 is a diagram showing the bypass valve 11tl + control in the turbo compound engine of the present invention. FIG. 4 is a flowchart of a program for operating the control means by a microcomputer, and FIG. 5 is a diagram showing the characteristics of a general turbo compound engine. 2: Internal combustion engine 4: Exhaust pipe 5: Turbo supercharger 8: Turbine 9: Connection pipe 10: Bypass valve 12: Power turbine 14: Planetary tooth width reducer 16: Fluid clutch 18
: Reduction n 1: Crankshaft 25-way one-way clutch
36: Electronic tIIItla device 36. 37: Oil pressure sensor patent applicant Isuzu Motors Co., Ltd. Agent Patent attorney Toshio Yamamoto Flag circular book review χ 攬萬 0 輛 1 5 Figure 2 FIA Figure 3 Figure 4

Claims (3)

[Claims] (1) Engine lubricating oil supplied to the bypass valve installed between the turbocharger and the power turbine connected downstream, and the fluid clutch that transmits the rotation of the power turbine to the engine crankshaft. A turbo compound engine comprising: control means for opening and closing a bypass valve in relation to hydraulic pressure. (2) The control means includes an oil pressure sensor on the oil inlet side of the power turbine, an actuator that drives the bypass valve, and an electronic control device that operates the actuator and closes the bypass valve when the inlet oil pressure exceeds a predetermined value. , a turbo compound engine according to claim (1). (3) The control means includes an oil pressure sensor on the oil inlet side of the power turbine, an oil pressure sensor on the extraction port side, and an actuator that drives a bypass valve, and when the inlet oil pressure becomes a predetermined value or more, the actuator closes the bypass valve, and an electronic control device that causes the actuator to open the bypass valve when the outlet oil pressure falls below a predetermined value.
The turbo compound engine described in 1).