JPH11294175A - Differential driven type supercharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a smooth torque characteristic and favorable operational feeling even during the shift operation by taking the output of an engine and the output of a continuously variable transmission as the power of a power transmission system in a system of driving a mechanical supercharger through a differential driving device by the power of the power transmission system extending from the engine to a vehicle. SOLUTION: The output of an engine 1 is transmitted to a driving wheel 4 of a vehicle through a main clutch 2 and a continuously variable transmission 3, a carrier 5b of a differential driving device 5 is driven through a first gear transmission 6 by the output of the engine 1, and a ring gear 5c is driven through a second gear transmission 7 by the continuously variable transmission 3. A mechanical supercharger 8 is driven by a sun gear 5a of the differential driving device 5, but in this case, the transmission ratio of the differential driving device 5 is selected, and when the rotating speed of the engine (correspond to the speed of the carrier 5b) is increased and the speed of the vehicle (correspond to the speed of the ring gear 5c) is increased, the rotating speed of the mechanical supercharger (correspond to the speed of the sun gear 5a) is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential drive type supercharger, and more particularly to a differential drive type supercharger for supercharging an engine for driving a vehicle such as a car, a truck, and a construction machine.

[0002]

2. Description of the Related Art A differential drive type supercharger is disclosed in Japanese Patent Application Laid-Open No. 8-189370 as shown in FIG. In this differential drive type supercharging device, an engine 51 drives a drive wheel 54 of a vehicle via a clutch 52 and a stepped manual transmission 53 (in the example shown in FIGS. 8 and 9). The output of the engine 51 and the output of the manual transmission 53 drive a mechanical supercharger 58 via a differential drive device 55. In FIG. 8, the vehicle speed is increased by increasing the engine speed by setting the transmission 53 to the first gear, and when the engine speed is increased to the position (1), the transmission 53 is set to the second speed and the engine speed is reduced. , The engine speed is increased again to increase the vehicle speed. When the second speed, third speed, and fourth speed of the transmission 53 are increased in the same manner as the first speed, the engine speed is increased to increase the vehicle speed, and when the engine speed is increased to the position (4), After setting the transmission 53 to five speeds and reducing the engine speed to the position, the engine speed is increased again to increase the vehicle speed. Therefore, the mechanical supercharger 58
As shown in FIG. 9, the rotational speed of (1) −− (2) −− (3) −− (4) − as shown in FIG. As shown in FIG.

[0003]

For this reason, according to the prior art, the driving force is not transmitted to the mechanical supercharger 58 during the gear shifting operation, and the rotational speed of the mechanical supercharger 58 decreases with the rotation speed of the engine 51. The decrease in the speed and the occurrence of a saw-toothed step (gap) in the speed of the mechanical supercharger 58 before and after the shift as shown in FIG. There was a risk of damaging the ring.

SUMMARY OF THE INVENTION The present invention has been made to solve the conventional problems, and provides a differential drive type supercharging device capable of obtaining a smooth torque characteristic and a good driving feeling even during a shift operation. The purpose is to do.

[0005]

In order to achieve the above object, a first invention of a differential drive type supercharging device according to the present invention is to provide a differential drive device using power of a power transmission system from an engine to a vehicle. In a differential drive type supercharger that drives a mechanical supercharger through the power of the power transmission system, the output of the engine,
And the output of a continuously variable transmission installed in the power transmission system.

According to the configuration of the first invention, the mechanical supercharger is driven at a high speed increase ratio at a low engine speed and at a low speed increase ratio at a high engine speed by selecting the speed ratio of the differential drive device. be able to. Therefore, when the engine speed is low, the torque increase ratio of the mechanical supercharger is increased to obtain high torque by high supercharging, and when the engine is high speed, the speed increase ratio of the mechanical supercharger is decreased to reduce the torque by low supercharging. Torque is obtained. In addition, a continuously variable transmission installed in the power transmission system provides a smooth, stepless shifting torque characteristic from high torque at low engine speed to low torque at high engine speed.

[0007] A vehicle requires a higher torque in a lower speed region to generate acceleration at the time of starting the vehicle, a traction force when climbing a steep hill, and a sticking of a construction machine at the time of low-speed pushing work. In order to achieve such torque characteristics, if the torque characteristics of the engine are set to low speed and high torque, good acceleration response of the vehicle and high hill climbing performance can be obtained, as if a large displacement engine was installed. The machine can get the low speed stick. On the other hand, at high speeds, the speed is automatically changed to a low speed increase ratio, resulting in low supercharging and low torque.However, since the generated torque of the engine is relatively high, the required capacity of the mechanical supercharger is relatively higher than that in the low speed region. May be low. For this reason, the drive loss horsepower of the mechanical supercharger in the high-speed region can be reduced, and the fuel consumption rate can be improved.

[0008] A second invention of a differential drive type supercharger according to the present invention is provided in front of the mechanical supercharger in the first invention,
A turbocharger that pre-presses the air taken in by the mechanical supercharger, or is interposed between the mechanical supercharger and the engine,
A turbocharger for supercharging air discharged from the mechanical supercharger to the engine is provided.

According to the structure of the second aspect of the invention, when the turbocharger is arranged in front of the mechanical supercharger, the increase in exhaust energy due to the increase in torque is based on the increase in torque by the mechanical supercharger in the low engine speed range. The increase in the rotational speed of the turbocharger is called, and the increase in the intake pressure thereby makes it possible to further increase the torque. Also, if a turbocharger is placed between the mechanical supercharger and the engine, high turbocharge and high torque by the mechanical supercharger in the low and medium speed range of the engine are basically used, but as the engine speed increases, the exhaust As the energy increases, the turbocharger intake pressure begins to decrease. For this reason, the outlet side pressure of the mechanical supercharger is reduced, and the driving horsepower of the mechanical supercharger is reduced, so that the output of the engine can be increased due to the inherent characteristics of the turbocharger.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. In FIG. 1, an output of an engine 1 is transmitted to a driving wheel 4 of a vehicle via a main clutch 2 and a continuously variable transmission (hereinafter referred to as CVT) 3 such as a CVT. Here, the vehicle refers to a passenger car, a truck, a special vehicle (a fire truck, a crane truck, a forklift, etc.), and a construction machine (a dump truck, a wheel loader, a bulldozer, etc.). The differential drive device 5 includes a sun gear 5a, a carrier 5b, and a ring gear 5c. The output of the engine 1 drives the carrier 5b via the first gear transmission 6, and the power from the engine 1 to the drive wheels 4 The ring gear 5c is driven via the second gear transmission 7 by the output shaft of the CVT 3 installed in the transmission system. The mechanical supercharger 8 is configured to be driven by the sun gear 5a of the differential drive device 5. Reference numeral 12 denotes a drive wheel brake.

The operation of the first embodiment will be described. Originally, such vehicles require higher torque at lower speeds to generate acceleration when the vehicle starts, to increase tractive force when climbing steep hills, and to stick at the time of low-speed pushing work with construction machinery. Is done. In order to obtain such torque characteristics, the speed relationship between the sun gear 5a, the carrier 5b, and the ring gear 5c of the differential drive device 5, as shown in FIG. 2, is that the engine rotation speed (corresponding to the speed of the carrier 5b) e is e1. ~ E
When the vehicle speed (corresponding to the speed of the ring gear 5c) v increases from v1 to v5, the mechanical supercharger rotational speed (corresponding to the speed of the sun gear 5a) s becomes approximately s1 to s5.
(However, in FIG. 2, the sun gear 5
a and the planetary gear 5d are shown with the same number of teeth for convenience). When the differential drive device 5 is configured in this manner, the ratio (s) of the mechanical supercharger rotation speed s to the engine rotation speed e
/ E) is a high speed increase ratio such as (s1 / e1) when the engine 1 is at a low speed, as shown in FIGS.
When the engine 1 is running at high speed, the mechanical supercharger 8 can be driven at a low speed increase ratio such as (s5 / e5). The engine rotation speeds (e1 to e5) and the mechanical supercharger rotation speeds (s1 to s5) are the same as those shown in FIGS.

Therefore, when the speed of the engine 1 is low, the speed increase ratio of the mechanical supercharger 8 increases, and a high torque is obtained by high supercharging. When the speed of the engine 1 is high, the speed increase ratio of the mechanical supercharger 8 is increased. Is reduced, and low torque is obtained by low supercharging. further,
By the CVT 3 installed in the power transmission system, a continuous and smooth shifting torque characteristic and driving feeling can be obtained without interrupting the torque from high torque at low speed to low torque at high speed of the engine 1.

FIG. 3 is a graph showing the relationship between the vehicle speed v and the engine speed e, with the horizontal axis representing the vehicle speed v and the vertical axis representing the engine speed e. When the throttle opening (TVO) is (6/8), the speed changes smoothly as in (1) to (5), and the throttle opening (TVO) is (4/8).
Similarly, at the time of, the stepless and smooth shifting is effected as shown in FIG.

FIG. 4 is a graph showing the relationship between the vehicle speed v and the mechanical supercharger rotation speed s, with the horizontal axis representing the vehicle speed v and the vertical axis representing the mechanical supercharger rotation speed s. Similarly to FIG. 3, when the throttle opening (TVO) is (6/8), the speed changes smoothly as in (1) to (5), and the throttle opening (TVO) becomes (4/8). Also in the case of ()), the speed is smoothly changed in a stepless manner.

In FIG. 3, the engine speed e increases as the vehicle speed v increases, and in FIG. 4, the mechanical supercharger rotation speed s decreases as the vehicle speed v increases above the vehicle speed v2.
The speed increase ratio (s / e) of the mechanical supercharger rotation speed s to the engine rotation speed e is a high speed increase ratio (s1 / e1) when the engine 1 is low speed, and is a low speed increase ratio (s1 / e1) when the engine 1 is high speed. s5 / e5). Thus, engine 1
At low speeds, the mechanical turbocharger rotation speed is high (s1
/ E1), the torque characteristics of the engine become low-speed and high-torque, and the vehicle has good acceleration response and high hill-climbing performance as if the large displacement engine 1 were mounted. The endurance can be obtained. On the other hand, when the engine 1 is running at high speed, the mechanical supercharger rotation speed automatically changes to a low speed increase ratio (s5 / e5), so that the supercharging becomes low and the torque becomes low. Due to the high capacity, the required capacity of the mechanical supercharger 8 may be relatively lower than that in the low speed range. For this reason, the drive loss horsepower required for driving the mechanical supercharger 8 in the high speed region can be reduced, and the fuel consumption rate can be improved.

If the CVT 3 is controlled so as to have a higher reduction ratio as the vehicle descends more steeply, the speed increase ratio of the mechanical supercharger 8 by the differential drive device 5 is set higher, so that the intake pressure increases. The drive loss horsepower increases. Therefore, the engine braking force can be increased to effectively increase the engine braking performance when the vehicle is going downhill. Further, the effects of the exhaust brake and the compression brake can be increased. The CVT has been described as the continuously variable transmission, but is not limited thereto.

The second embodiment of the present invention shown in FIG. 5 is different from the first embodiment shown in FIG. 1 in that a turbocharger 9 is disposed in front of the mechanical supercharger 8 so that the mechanical supercharger 8 can be used. It is the same as the first embodiment except that it is a hybrid supercharger for preloading the air to be taken.

According to the configuration of the second embodiment, in the low engine speed range, the increase in the exhaust energy due to the increase in the torque is referred to as the increase in the rotational speed of the turbocharger 9, based on the increase in the torque by the mechanical supercharger 8. As a result, the torque can be further increased due to the increase in the intake pressure. As the exhaust energy increases as the engine speed increases, the discharge pressure of the turbocharger 9 gradually starts increasing. Therefore, if the engine 10 is directly supercharged by the turbocharger 9 by disengaging the clutch 10 and opening the bypass valve 11, the driving horsepower of the mechanical supercharger 8 is reduced and the output of the engine is increased.

The third embodiment of the present invention shown in FIG. 6 differs from the first embodiment shown in FIG. 1 in that a turbocharger 9 is interposed between a mechanical supercharger 8 and an engine 1 to provide a mechanical supercharger. Feeder 8
This is the same as the first embodiment except that a hybrid supercharging device for supercharging the air discharged from the engine 1 to the engine 1 is used.

The configuration of the third embodiment is based on high supercharging and high torque by the mechanical supercharger 8 in the low and medium speed range of the engine. However, as the engine speed increases, the exhaust energy increases. Then, the intake pressure of the turbocharge 9 starts to decrease gradually. As a result, the outlet pressure of the mechanical supercharger 8 is reduced, and the driving horsepower of the mechanical supercharger 8 is reduced.
The output of the engine 1 can be increased from the original characteristics of the turbocharger 9. Further, when the engine speed increases, the clutch 10 is disconnected and the bypass valve 11 is opened to supercharge the engine 1 directly by the turbocharger 9 as in the second embodiment, thereby driving the mechanical supercharger 8. The horsepower is reduced, and the output of the engine is increased.

[Brief description of the drawings]

FIG. 1 is a view showing a first embodiment of a differential drive type supercharging device according to the present invention.

FIG. 2 is a diagram illustrating a speed relationship between components of the differential drive device shown in FIG. 1;

FIG. 3 is a diagram illustrating a relationship between a vehicle speed and an engine rotation speed according to the first embodiment.

FIG. 4 is a diagram illustrating a relationship between a vehicle speed and a mechanical supercharger rotation speed according to the first embodiment.

FIG. 5 is a view showing a second embodiment of the differential drive type supercharging device according to the present invention.

FIG. 6 is a view showing a third embodiment of the differential drive type supercharging device according to the present invention.

FIG. 7 is a diagram showing a differential drive type supercharging device of the prior art.

FIG. 8 is a diagram showing a relationship between a vehicle speed and an engine rotation speed according to the related art.

FIG. 9 is a diagram showing a relationship between a vehicle speed and a mechanical supercharger rotation speed according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Main clutch 3 CVT 4 Drive wheel 5 Differential drive device 5a Sun gear 5b Carrier 5c Ring gear 6 First gear transmission device 7 Second gear transmission device 8 Mechanical supercharger 9 Turbocharger 10 Clutch 11 Bypass valve 12 Drive wheel brake

Claims (2)

[Claims] 1. A mechanical supercharger via a differential drive unit (5) by the power of a power transmission system from an engine (1) to a vehicle.
In the differential drive type turbocharger that drives (8), the power of the power transmission system shall be the output of the engine (1) and the output of the continuously variable transmission (3) installed in the power transmission system. A differential drive type supercharging device characterized by the above-mentioned. 2. The turbocharger (9) according to claim 1, which is arranged in front of the mechanical supercharger (8) and preloads air taken in by the mechanical supercharger (8). A turbocharger interposed between the turbocharger (8) and the engine (1) for supercharging the air discharged by the mechanical supercharger (8) to the engine (1).
(9) A differential drive type supercharging device comprising: