JPS63280823A - Supercharging system for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve a low speed torque without sacrificing the fuel cost and output of the low load side and the high load side of an engine by providing a disk wheel at a space between the pump of a torque converter and a stator, and connecting this disk wheel and a turbo charger by means of a line of gears. CONSTITUTION:At a torque converter Tq comprising a pump 1, a turbine and a stator 3, is provided at a space between the pump 1 and the stator 3 a disk wheel 4, which is fixed at a hollow shaft 8 at whose other end is fixed a gear 9. Meanwhile, at a turbo charger Tc which comprises a compressor 10 and an exhaust turbine 11 both of which are connected with a shaft 12, a planetary gear device 13 is provided at the shaft 12, and while its sun gear S is fixed at the shaft 12, a gear 14 is fixed at a planet carrier C, and this gear 14 is made to mesh with the above-stated gear 9. As a result, at a low revolution sphere, the torque of the pump 1 is torque-distributed to an output shaft 6 and the disk wheel, and the turbo charger Tc is made drivable.

Description

[Detailed description of the invention] The present invention relates to a supercharging system for an internal combustion engine.

The present inventor proposed a turbo compound system in which the power of a Lee power recovery turbine is introduced into a torque converter in Patent Application No. 59654 of 1980.

Furthermore, in Patent Application No. 082229 filed in 1988, the company proposed a supercharger drive system in which the supercharger is driven by a torque converter.

By combining the two, the present invention improves low-speed torque without sacrificing fuel efficiency and output on the low-load side and high-speed side of the supercharged engine, and improves efficiency by recovering exhaust heat. It is something that we try to improve.

In other words, by providing another impeller within the torque converter consisting of the pump, turbine, and stator, and connecting this impeller to the turbocharger, the impeller within the torque converter is used to control the turbocharger in the low engine speed range. The idea is to use the engine exhaust to drive the turbocharger in the high engine speed range, and to recover some of the exhaust heat as shaft power using a torque converter.

Therefore, the present invention is a structurally simplified invention that realizes the functions of both a turbo compound engine and a hybrid supercharging system using only one turbocharger.

The present invention will be explained in detail based on the drawings.

Tq is a torque converter, and Tc is a turbocharger with a planetary gear device 13 mounted on the rotating shaft.

First, the explanation will proceed from the torque converter Tq side.

1 is a pump, 2 is a turbine, and 3 is a stator. 4 is a blade wheel installed between the pump 1 and the stator 3. 5 is a driving shaft of a torque converter Tq connected to a crankshaft of a base engine (not shown), and the pump 1 and driving shaft 5 are connected. 6 is a driven shaft (output shaft) of the torque converter Tq, and is coupled to the turbine 2. Reference numeral 7 denotes a one-way clutch that rotates in the same direction as the turbine 2, and the stator 3 is fixed via the one-way clutch 7 to a transmission (no colored thread).

8 is a hollow shaft fixed to the impeller 4, and a gear 9 is attached to the other end.
is fixed. Therefore, 4.8 and 9 are rotatable with respect to the shaft of the stator 3 and the driven shaft 6.

Next, the explanation will proceed from the turbocharger Tc side.

10 is a compressor, 11 is an exhaust turbine/, 12
is an axis connecting 10 and 11. A portion 13 surrounded by a broken line is a planetary gear device. 13, S is a sun gear fixed to the shaft 12, P is a pinion, and C is the pinion P.
The planet carrier supporting the , R is the ring gear.

Ring gear R is fixed and does not rotate. 14 is a gear fixed to the planet carrier C. 15 is an intermediate gear, and this 15 meshes with the gears 14 and 9.

Incidentally, the planetary gear device 13 and the impeller 4 may be connected by a belt.

Next, the operation of each element constituting the present invention will be explained.

First, let's talk about the gear train. In the planetary gear device 13, when the ring gear R is fixed, the speed ratio i of the sun gear S and the planet carrier C is expressed by the following formula: % zR: number of teeth of the ring gear R. Therefore, ZJI:
If ZR-1:5, the gear ratio of the planetary gear unit 13 is i
-6. In other words, planet carrier C/gear S
The rotation ratio is 1:6. And Planet Carrier C
If the gear ratio of the gear 14 fixed to the impeller 4 and the gear 9 fixed to the impeller 4 via the hollow shaft 8 is set to 1:4, the gear ratio of the entire gear train will be 24, so for example When the rotation speed of the impeller 4 is 5.000 rpm, the rotation speed of the turbocharger Tc is 120.00 Orpm.

Next, the torque converter TqK will be explained.

Since the fluid in the torque converter circulates through the circuit and returns to its initial state, the sum of the torques T applied to the fluid from each impeller in the circuit becomes zero.

In the low engine speed range where exhaust energy is insufficient, the torque of the pump 1 is divided between the turbine 2 and the impeller 4K). The torques at the pump 1, turbine 2, stator 3, and impeller 4 are T l sTl, Ts, T4, respectively.
Then, since Σr=o, T4 = Ts+
In the low speed range, the impeller 4 plays the role of a turbine for driving the turbocharger Tc.

For a two-element torque converter, the energy head H imparted by the i-th impeller per unit weight of fluid is given by:

H= Tiωi / rQ = (L/?)Δ(yω
y,)i where, ω: rotational angular velocity of the impeller, γ: specific weight of the fluid, Q: circulation flow rate, t: acceleration of gravity, r: radius of the impeller from the rotating shaft, v: absolute velocity of the two fluids The rotational component of
i: Impeller number.

In the high engine speed range where the exhaust energy increases, the turbocharger Tc is driven by the engine exhaust gas.

When the rotational speed of the turbocharger Tc increases, the rotational angular velocity ω4 of the impeller 4 directly connected to the turbocharger Te also increases, and energy is given to the fluid from the impeller 4 according to the above energy equation. Torque T given to the fluid by the impeller 4
4 is 14 to 7'! 71 7s. Therefore, in the high speed range, the impeller 4 plays the role of a pump, and instead of consuming shaft power to drive the turbocharger Tc, it recovers a portion of the exhaust energy.

For changes in engine load, from the above energy formula,
The energy T1ω1/γq given by the pump 1 to the fluid changes, and as a result, the energy T4ωa/rq given from the fluid to the impeller 4 also changes, so the rotational speed and rotation of the impeller 4 change according to changes in engine load. The power changes automatically and the flow rate of the turbocharger Tc can be changed. In other words, in conventional mechanically driven positive displacement superchargers, the flow rate of the supercharger changes only depending on the engine speed, but in the present invention, the flow rate of the compressor IO increases or decreases depending on the engine load, so excess air supply is generated at low load. There is no need to supply it to the engine.

The influence on the transient response of this method of connecting the supercharger and output shaft via a torque converter is determined by the specific weight of the gas ejected from the turbine scroll to the exhaust turbine 11.
Because the specific weight of the fluid circulating within the torque converter is much greater, the energy per unit volume of fluid imparted to the impeller is much greater in a torque converter than in a turbocharger, and is therefore much higher than in a conventional turbocharged engine. Response is improved.

Next, regarding the turbocharger Tc, the operating range of the compressor 10 will be explained with reference to a barrier pull geometry (VG) turbocharger. The VG turbo developed by Mitsubishi Motors Corporation has multiple nozzle vanes arranged in the annular part at the inlet of the turbine rotor to make them variable, and does not convert the compressor into a VG. Even if only the turbine was converted to VG, due to the characteristics of the existing compressor, there was a surge margin when the turbine nozzle area was minimized.

Also, Nissan Motor Co., Ltd.'s variable displacement turbocharger with a movable flap does not have a VG compressor.

Therefore, in the case of the present invention, even if the rotational speed of the compressor 10 is forcibly increased in the low-speed, high-load region of the engine, it is considered possible to operate the compressor 10 without entering the surging region.

The effects of the present invention are listed below.

1) Since the supercharger and the crankshaft are connected through the fluid of the torque converter Tq, the torque converter Tq plays the role of a buffer mechanism, absorbing sudden fluctuations in engine speed and load. It is possible to protect the turbocharger Tc, which rotates at extremely high speed.

11) In the low engine speed range, the torque converter T
Since the turbocharger Tc is driven by the q inner wheel 4, the supply pressure can be increased in the low speed and high load range.

Therefore, low speed torque is improved.

Further, since the turbocharger Tc can have a relatively large capacity, the engine/engine exhaust pressure is reduced and efficiency is improved.

1ii) In a high engine speed range, the engine exhaust gas drives the exhaust turbine 11, so no shaft power is consumed and exhaust energy is recovered. Therefore, both fuel efficiency and output at high speeds are improved.

iy) At partial loads, the torque controller (-ta T)
Since the torque received by the impeller 4 in q decreases, the rotational speed of the turbocharger Tc also decreases, and the flow rate of the compressor 10 decreases, so no excess air is supplied to the engine, and part-load fuel consumption is reduced. Improved.

■) When the engine load suddenly increases during acceleration or when climbing, the speed ratio of the impeller 4 in the torque converter q decreases, so the torque ratio of the impeller 4 increases, causing its rotation speed to suddenly increase. Therefore, the turbo lag of the turbocharger Tc directly connected to the 4 can be eliminated, and the response can be improved.

The present invention is a practically useful invention having a simple structure and the above-mentioned effects.

[Brief explanation of drawings]

The drawings are schematic diagrams showing the configuration of the present invention. In the figure, Tc: turbocharger, Tq:) lux converter, 1: pump, 2: turbine, 3: stator, 4
: Impeller, 5: Driving shaft, 6: Driven shaft, 7: One-way clutch, 8: Hollow shaft, 9: Gear, 10: Compressor, 11
: Exhaust turbine, 12: Shaft, 13: Planetary gear system, 14
．． 15: Gear, C: Planet carrier, P: Pinio/
, R: ring gear, S: sun gear.

Claims (1)

[Claims] The torque converter consists of a pump, a turbine, and a stator. A blade wheel is installed between the pump and the stator, and the blade wheel and turbocharger are connected by a gear train. In the low engine speed range, the torque converter changes the pump's torque. Torque is distributed between the output shaft and the impeller, and the impeller drives the turbocharger to supply air. In high engine speed ranges, the engine exhaust drives the turbocharger, and the torque converter generates exhaust heat. A supercharging system for internal combustion engines that recovers a portion of the engine load and automatically adjusts the compressor flow rate according to changes in engine load.