Electronic control for vehicle four wheel drive system

Details Electronic control for vehicle four wheel drive system Electronic control for vehicle four wheel drive system

1987-12-23

1990-06-26

Lall, Parshotam S.

Boots, shoes, and leggings

36442603, 180248, 180249, 192103F, B60K 1734

Patent

active

049377507

ABSTRACT:
A microcomputer-based electronic control system for a full time four wheel drive torque transfer case monitors the relative slip between the front and rear output shafts of the transfer case, and generates a signal to engage an electromagnetic clutch for a predetermined time period in the event a predetermined slip threshold is exceeded. Below a predetermined vehicle road speed, the electronic control utilizes a pulse counting technique to determine whether or not an excessive slip condition occurs. Above the predetermined speed, the control compares the front and rear output shafts speeds to determine whether there is excessive slippage. During the first portion of the clutch engagement period, the clutch is fully engaged while, during the last portion, a partial clutch engagement signal is generated to cause the clutch to gradually move from a fully engaged condition to a fully disengaged condition. The length of time the clutch is engaged can be a function of the vehicle road speed. The slip threshold can also be a function of the vehicle road speed, and can vary depending on whether the front or rear output shaft is rotating faster. The electronic control compares the output shaft speeds after the clutch is engaged to check the mechanical condition of the clutch. Also, in the event the microcomputer fails to discontinue the generation of the clutch engagement signal, a failsafe time out circuit will automatically turn off the clutch.

REFERENCES:
patent: 4298085 (1981-11-01), Morota et al.
patent: 4320813 (1982-03-01), Manna
patent: 4417641 (1983-11-01), Kageyama
patent: 4433748 (1984-02-01), Satoh et al.
patent: 4466502 (1984-08-01), Sakai
patent: 4467886 (1984-08-01), DeClaire et al.
patent: 4470489 (1984-09-01), Makita
patent: 4484653 (1984-11-01), Horikoshi et al.
patent: 4499450 (1985-02-01), Makita
patent: 4511014 (1985-04-01), Makita
patent: 4538700 (1985-09-01), Suzuki
patent: 4552241 (1985-11-01), Suzuki
patent: 4556134 (1985-12-01), Takano
patent: 4558414 (1985-12-01), Sakakiyama
patent: 4560025 (1985-12-01), Suzuki et al.
patent: 4562541 (1985-12-01), Sakakiyama
patent: 4566554 (1986-01-01), Suzuki
patent: 4576061 (1986-03-01), Yamakawa et al.
patent: 4582159 (1986-04-01), Suzuki
patent: 4586583 (1986-05-01), Yamakawa et al.
patent: 4609064 (1986-09-01), Suzuki et al.
patent: 4613008 (1986-09-01), Hiraiwa et al.
patent: 4630704 (1986-12-01), Yamakawa et al.
patent: 4702341 (1987-10-01), Taga et al.
patent: 4715466 (1987-12-01), Ishii et al.
patent: 4754834 (1988-07-01), Ozaki et al.
patent: 4754835 (1988-07-01), Stelter et al.
patent: 4757870 (1988-07-01), Torii et al.
patent: 4765434 (1988-08-01), Kawamoto et al.
patent: 4776421 (1988-10-01), Kashihara

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