A cvt-oriented pre-type functional mechanism and its control method

Abstract

The invention discloses a front-mounted type functional mechanism for a CVT and a control method thereof. The front-mounted type functional mechanism comprises a shell; an input shaft, an intermediateshaft and an output shaft are arranged in the shell and are coaxially arranged in sequence; the input shaft and the intermediate shaft are connected through a first planetary row to realize transmission; the intermediate shaft and the output shaft are connected through a third planetary row to realize transmission; and a second planetary row is arranged between the first planetary row and the third planetary row and is connected to the intermediate shaft, the first planetary row and the third planetary row to realize transmission. The realizable front-mounted type functional mechanism for theCVT and the corresponding control method have the advantages that the structure is simple, the park gear, reverse gear, neutral gear and driving gear functions required by an automatic transmission can be achieved by controlling the cooperative action of a damper brake, an independent reversing gear mechanism and corresponding engine control over reverse do not need to be separately designed, andtherefore the system structure can be optimized, and the system control convenience can also be improved.

Description

technical field [0001] The invention relates to a CVT-oriented pre-type functional mechanism and a control method thereof. Background technique [0002] Vehicles with wheeled continuously variable automatic transmission (CVT for short) require a large number of core supporting technology devices in their actual structure and control, such as hydraulic systems, front or rear function realization mechanisms, and electronic and electrical systems. Guarantee the realization of the final stepless speed change. [0003] The front or rear-mounted functional mechanism is to realize the functions of vehicle parking P, reverse R, neutral gear N, and driving gear D, so that the stepless speed change within a certain range of the wheel pair can be further carried. Therefore, it is a very important part of the overall design of the CVT to design the corresponding front or rear functional mechanism. [0004] But there are following problems in the existing function mechanism: [0005] ...

AI Technical Summary

Problems solved by technology

[0005] 1. The technical barriers are relatively high. The existing automatic transmission technology is basically monopolized by foreign countries, and there are relatively few domestic auto companies that can conduct independent research and development

[0006] 2. The structure is complex, such as: various special-shaped structures, complex gear associations, one-way clutches, brakes, friction and locking, shells or parts with embedded pipelines, hydraulic systems, control valve bodies, etc., which are difficult to digest and copy. Manufacturing is also relatively difficult, and it also involves more program control, requiring a large number of control models to achieve productization

[0007] 3. The post-maintenance and use of the product have relatively high requirements for professionals, and the cost is relatively high

[0008] 4. The components of the prior art products are all specific and have low versatility

[0009] 5. The existing gear shifting requires complex thrust cylinder control design, and the control switching of thrust cylinders such as reverse gear, parking, and neutral gear needs to be considered, and the hydraulic system is relatively complicated.

[0010] 6. The existing CVT structure needs to design the reversing mechanical transmission gear structure separately, and the reversing transmission ratio cannot be adjusted, which is generally a definite value

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