Test drive Honda Civic Sedan 1995 - 2000 sedan

Everything can CVT

For the first time in the Russian market, a car without a gearbox.
In front of me, it seems, the completely ordinary Honda Sivik (ZR, 1997, No. 1). At the stern - 1.6Iec and VTEC signs. Everything is clear - a 1.6 -liter engine with a mechanism for changing the height of the valve lifting. I get into the car. Two pedals and selector are also familiar to anyone who is familiar with the machine gun. I let the engine, taxi on the avenue and advance on the accelerator. And then miracles begin ...
The arrow of the tachometer, jumping to 4000 rpm, as if glued to this mark - taking a note, the motor holds it without getting down. The car, know yourself, accelerates and accelerates, powerfully and, most amazing, absolutely evenly, without a hint of jerks that accompany the gear shifts even at a good machine gun. There is something very familiar in such an even acceleration ... Well, of course! It is typically trolleybus!
Meanwhile, a red eye of a traffic light appeared ahead - there is nothing to do, I attach it for some nine. Well, it's time to open the cards.
The fact is that on my Honda is not a hydromechanical automatic transmission, but a stranded CVT variator (Continously Variable Transmission). Yes, an ordinary wedge-rephid variator. Although about the usual one, I got excited. It is largely unusual. However, we will not rush - to the place of basic trials still go and go. First a little theory.
In any internal combustion engine, the maximum power values, moment and minimum specific fuel consumption are achieved only at strictly defined speeds. When accelerating on each gear, the engine works with the greatest dedication only in some moments, jumping the maximums of its characteristics. In addition, each switch, not to mention the loss of time, is accompanied by a longitudinal jerk - there is no traction on the drive wheels with squeezed adhesion.
Automatic gearboxes are somewhat better. The hydrotransformer allows you to not interrupt the power of the power brought to the wheels, and smoothly change the gear ratio, although in a rather narrow range - on average from 1 to 2. at the same time, a small transformation coefficient did not allow the machine to completely abandon the stepping transmission numbers.
There is a third solution. About him will be discussed. This is the mentioned understanded variator, smoothly changing the gear ratio. The most famous is the cuneiform. The principle of its action is clear from the drawing. If you spread or move two plate -shaped halves of the pulley, then the wedge -shaped belt will either fall into a small radius of contact, or be replaced by a large one. Usually, two such pulleys working in antiphase are connected to the belt (that is, one shifts and the other is parted). As a result, the gear ratio is expanded and the need for an additional stretch roller disappears.
Cleanimal variators are widely used on motorckers and snowmobiles, but on cars they did not immediately take root. And for a clear reason. The clutch of the pulley and the belt occurs only due to the friction force, and in order to increase it to transmit high power, it is necessary to pull the belt more strongly. This very reduces its resource. On a five thousand -thousand scooter, a rubber belt walks 10-15 thousand kilometers, and on a liter snowmobile - several times less. But the last one is, rather, a toy, and the mileage for the season is usually small. Another thing is a car - here and an annual mileage sometimes tens of thousands of kilometers, and the power of engines is higher. Who wants to change an expensive belt several times a year, and even with disassembling the gearbox?
The engineers of the plant in Hamamatsu used a structure with a steel pushing belt, which was used on Ford-phiests, and on the Fiat Uno and Panda, and on a number of other models (ZR, 1988, No. 1). The Honda Sivik belt is typed from steel trapezoidal segments with a thickness of 1.5 mm, in the side grooves of which 12 rings from a flexible steel tape are laid on both sides. When asked about the resource, Honda representatives modestly replied that they had some problems with this, until they selected the materials correctly.
Not satisfied with the oral certificate, which, as you know, you can’t get it to the case, I was not too lazy to look into the service book of the test sivik. Surprisingly, the fact: every 20 thousand km there is only a general verification of the variator, as well as the brakes, the steering, headlights, tires and much more. No replacement of the belt for 200 thousand km, for which all service operations are painted, is not provided. So the belt resource was equal to the resource of the motor, body and ordinary gearbox. Well, now, having shoved theoretically, you can go to practice. Moreover, during the conversation we have already reached the goal - a deserted country highway.
The transmission management with the variator does not differ from the automatic: the leg to the brake, the selector from position P to D. You release the brake - the machine begins to crawl forward (a multi -disc clutch that works in an oil bath allows slippage, so it turns on very softly), add gas - it goes faster. Depending on how you press the accelerator, the tachometer shooter freezes at smaller or large revolutions and sivik, respectively, accelerates slower or faster. Upon reaching some speed, the turns are slightly reduced, the acceleration disappears and the green icon ECON venerates - the engine goes into an economical mode of operation. At the same time, for example, at a speed of 80 km/h the motor develops 2000 rpm. By sharply pressing the accelerator, you can raise speeds to 5500 rpm, on which up to about 140 km/h is accelerated, after which the speed begins to smoothly decrease, and the speed continues to grow. The coefficient of changes in the gear ratio of the variator is quite large - 5.5 (from 2.466 to 0.449).
In addition to the position of the selector D, two more are provided: S - sports and l - lowered. In the first of them, at a speed of 80 km/h, 3000 rpm are maintained, in the second - 4500 rpm. That is, the engine develops the power required for movement at high speeds and a smaller torque, using a higher gear ratio of transmission. Accordingly, he needs less time to unwind for maximum return. Acceleration at a full throttle in both cases occurs at about 6500 rpm, when the motor gives all its 115 liters. With. At the same time, there are no speed restrictions - in L, the car will develop the same maximum 170 km/h, only will do it faster. In addition, depending on the position of the selector, the variator control algorithm changes.

Unlike a regular machine, there are no speed restrictions when changing the modes for moving forward. For example, to increase the efficiency of braking by the engine (without fear of twisting it), you can go from D to S or even L. There is no thought inherent in hydromechanical boxes of thought here - the machine goes behind the pedal, almost like with mechanics.
Honda studies have shown that in comparison with a conventional four-speed CVT automatic machine, it provides 15 percent fuel savings in urban modes and winning 1.7 C when accelerating at a distance of 400 m from a place. Moreover, at the same distance, CVT wins 0.1 C and mechanics.
Well, did you like the variator? The answer can be foreseen. Meanwhile, the capabilities of the variator are not exhausted by the above. Imagine such a situation. Do not feed you bread, but let you make a boom with a lever of the box, grunting the engine. Wife, by and large, needs two pedals and steering wheel - she cannot stand your comments about the incorrectly selected program. Mother -in -law (if she is also with rights) for traveling to the store generally enough for one - first. But all this can CVT. Do you want to ask her, say, a stepped mode of operation, as in ordinary mechanics, and even with any number of gears and gear rates? Please. And he played enough - go to the usual regime and roll yourself, resting. By the way, according to the latest intelligence data, it is such a programmable variator that is being developed at the company of Zanradfrick for BMW and Volkswagen concerns. So, it seems, Honda Sivik is only the beginning of the latest history of the variator ...

CVT variator: 1 - flywheel; 2 - leading pulley;
3 - steel belt;
4 - front -line clutch; 5 - reverse clutch; 6 - a planetary reverse mechanism;
7 - driven pulley;
8 - clutch clutch;
9 - intermediate shaft with gears; 10 - Differential case.

Variator belt: 1 - steel trapezoid segments; 2 - a package of ribbons from steel tape.
Yuri Nechetov. Photo by Alexander Polunin
 

A source: The magazine "Driving"