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240 Landmarks TopTransmission and Drive Train > ESCOT (easy, safe, controlled transmission)
 ESCOT (easy, safe, controlled transmission)
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1. Japan's first semi automatic electronically controlled multi-speed transmission for heavy duty trucks. It was developed for heavy duty trucks whose weight changes widely when loaded or unloaded. Clutch operation on start and shift changes were determined by the driver, but all other controls were automated and an overdrive 12-speed transmission was applied. As a result, driver fatigue could be alleviated and accidents caused by mis-shifts could be prevented.
2. Except for starting and immediately before stopping, no clutch pedal operations were required. The shift-up or -down signals were created simply by tilting the shift lever forward or backward. As a result, acceleration and clutch operations were automated.
3. The main body of the transmission was a 12-speed transmission with a range shift function and high/low sub transmission. The driver could select the mode of operation: An individual speed mode that sequentially shifts all 12 speeds, and a mode skips every other gear as if using a 6-speed transmission.
4. The starting speed was set to the 3L speed if the shift lever was tilted forward (up) from the HOLD position, and to the 2L speed if tilted backward (down).
5. Driving instructions were sent simultaneously from the TM controller unit to the electronic governor controller in the engine and to the clutch actuator. Then the operation stroke signal of the clutch was sent back to the TM controller.
6. An indicator on the driver's seat showed the gear used by lighting up "1" to "6" or "HIGH" or "LOW".
7. Various types of backup for human error and device abnormality were provided. The transmission functions included one to prevent overrun accidents caused by mis-shifts, a self-diagnostic function, and an optimal gear selection function. In this function, if the driver is unable to decide which gear to select, the transmission was capable of immediately judging the optimal gear for the vehicle speed at that time once the driver moved the lever to the N position, and then shifted up or down.
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Storage location:NISSAN DIESEL MOTOR CO., LTD (Owner), CREATE CENTER (Administrator) (Owner: 1 Ageo-shi, Saitama-ken 362-8523, Administrator: 3-13-16 Yahei, Kawaguchi-shi, Saitama-ken 332-0002)
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Year manufactured:1995
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Manufacturer:Nissan Diesel Motor Co., Ltd.
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Classification:Prototype
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Current status:In storage: not open to the public
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Name / Manufacture
Model name:ESCOT
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Applied model:Heavy duty trucks and buses
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Year of manufacture:1995~2000
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Application year:1995
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Device structure:Transmission body (mechanical transmission), operation portion (driver side), display portion (driver side), control portion (electronically controlled unit), engine control portion (for electronic governor), clutch control portion
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Specification
Shift / operation method:Model type: MRT21, Type: Range shift type 12-forward speed transmission with splitter, Gear shift type: Electronically-controlled electromagnetic pneumatic type
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Gear ratio (forward):1L/1H: 10.729/8.702, 2L/2H:6.575/5.333, 3L/3H: 3.649/2.959, 4L/4H: 2.236/1.813, 5L/5H: 1.464/1.187, 6L/6H: 1.000/0.811
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Gear ratio (reverse):RevL/RevH: 9.563/7.756
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Operation method:Shift lever (individual speed/speed-skipping shift switch, and emergency manual switch), shift pattern (diagram), gear selection type (vehicle speed and engine speed)
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Potency
Function, effect, etc.:Shift functions: The starting speed was selected by manual clutch operation for standing starts only. Subsequently, during driving, the speeds were selected by automatic shift up/down based on lever operation and intermittent clutch engagement. The system was provided with an overrun prevention mechanism and a speed-skip function.
Backup function: Emergency manual speed change in the case of failure, abnormality self-diagnostics, function to prevent overrun accidents caused by mis-shifts.
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Effect:This system prevented driver fatigue and overrun accidents caused by mis-shifts. Fuel economy was improved by optimal shift selection, and safety was enhanced by effective engine braking on downhill sections.
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Points of interest, topicality:Japan's first multi-speed semi-automatic transmission for heavy duty trucks utilizing electronic control.
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Features:This was a semi-automatic multi-speed transmission developed for heavy duty trucks weight changes widely when loaded or unloaded. Clutch operation on start and shift changes were determined by the driver, but all other controls were automated and an overdrive 12-speed transmission was applied. Except for starting and immediately before stopping, no clutch pedal operations were required. Acceleration and intermittent clutch engagement were automated based on the shift-up or -down signals.
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Reference materials:Nobuo Hata, Yositaka Nishiayma, Sadahiro Takahashi, Yoshito Watanabe, "Development of an electronically controlled semi-automatic multi-speed transmission for heavy-duty tractors", Proceedings for JSAE Technical Paper Presentations 951, pp. 129-132 (No. 9534243)
Isao Okamoto, Takeshi Teshirogi, Shoji Okazaki, Nobuo Hata, Tadashi Suzuki, Takashi Kurosawa, "Denshi Seigyo Hensoku Souchi (ESCOT) No Kaihatsu", Nissan Diesel Technical Review No. 57, pp.. 86-91, Jun. 1956
Yoshitaka Nishiyama, Chokichi Nakazono, Hiroshi Miyake, Masakazu Sasaki, "Seitai Hannou Keisoku Niyoru Shin Hensoku Shisutemu 'ESCOT' NO Ijidoraibu-sei Hyoka Ni Tsuite", Nissan Diesel Technical Review No. 57, pp. 33-38, Jul. 1955
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