192 clutches and power-stop control – Transmission control and clutch control – Common control
Reexamination Certificate
1999-10-26
2001-02-20
Marmor, Charles A (Department: 3681)
192 clutches and power-stop control
Transmission control and clutch control
Common control
C192S111400
Reexamination Certificate
active
06189665
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a clutch disengagement and engagement apparatus, and more particularly to such an apparatus that can realize automatic operation of a vehicle clutch.
2. Description of the Related Art
Automatic clutch apparatuses for automatically disengaging and engaging a friction clutch are known in the art. With the automatic clutch apparatus, a clutch engagement speed is generally reduced in a partly engaged range in order to soften or eliminate shock which would otherwise be caused upon clutch engagement. However, the partly engaged range varies with wear and deformation of the clutch as well as assembly error. Therefore, it is necessary for the apparatus to repeatedly learn the partly engaged range of the clutch.
One of recent ways of learning the partly engaged range of the clutch is called “in-neutral learning method.” This is a method of studying a “drag position” of the clutch (i.e., a clutch-stroke-position at which the clutch partly engaged range or condition starts)” when a transmission is in a neutral condition and therefore it is also referred to as “drag position” study method. This approach will briefly be described below.
1) The clutch is automatically brought into a complete disengagement position after predetermined study conditions such as a transmission gear position (shift position) being a neutral, a vehicle being in standstill, etc., are met.
2) To wait until an output element (output shaft) of the clutch stops rotating.
3) When the rotation of the clutch output element stops, the clutch is automatically engaged slowly.
4) As the clutch engagement starts and the rotational speed of the clutch output element reaches a prescribed threshold value, then the clutch stroke position at that point is determined as the start of the partly engaged range.
5) The clutch is automatically brought into a complete engaged condition.
In this manner, the clutch is disengaged and engaged when the clutch-stroke-position learning is performed.
In the meantime, a manual transmission is sometimes combined with the automatic clutch apparatus so that the gear position change of the transmission is carried out by a driver's hand whereas the clutch disengagement and engagement is carried out automatically. With such combination, transmission gear engagement and disengagement is possible for a certain period since the clutch is first disengaged during the clutch-stroke-position learning. If a driver manually moves a shift lever into a particular gear position and transmission gear engagement is effected, then the vehicle will start upon clutch engagement. In particular, if the driver inadvertently causes the transmission gear engagement, the vehicle will start without driver's intention. This is not preferred.
It is also known to automatically change the gear position of the manual transmission by an actuator. If this technique is combined with the automatic clutch apparatus, the shift lever simply serves as a switch. Therefore, if movements of the shift lever are ignored by the software of the automatic clutch apparatus during the clutch-stroke-position learning, the above-described problem will easily be overcome. However, if the driver manually changes the gear position of the manual transmission by a mechanical device, the movements of the shift lever directly result in gear engagement and disengagement of the transmission gears. Thus, it is not possible to overcome the above-mentioned problem by the software design.
Other systems and methods for disengaging and engaging a clutch are disclosed in U.S. patent application Ser. Nos. 08/967,401 filed Nov. 11, 1997, Ser. No. 09/150,686 filed Sep. 10, 1998 and Ser. No. 09/207,180 filed Dec. 8, 1998, and International Patent Application No. PCT/JP98/02754 filed Jun. 19, 1998, all of which are entirely or partly assigned to the assignee of the instant application.
SUMMARY OF THE INVENTION
One of the objects of the present invention is to prevent a vehicle from starting during the clutch-stroke-position learning. Particularly, the present invention aims to prevent starting of a vehicle, which is equipped with an automatic clutch apparatus and manual transmission, during the clutch-stroke-position learning even if a vehicle driver accidentally causes the transmission gear engagement.
According to one aspect of the present invention, there is provided a vehicle including a clutch, an apparatus for automatically disengaging and engaging the clutch, a manual transmission of which gear position (shift position) is changed upon manually operating a shift lever, a controller for controlling the clutch automatic disengagement and engagement apparatus. The controller includes a learning unit for performing a clutch-stroke-position learning to detect a starting position of a partly engaged range of the clutch while the manual transmission is in a neutral position, and a unit for interrupting the operation of the clutch-stroke-position learning unit when the shift lever is operated toward a transmission gear engagement position (gear-in position) during the clutch-stroke-position learning. Since the clutch-stroke-position learning is stopped when the shift lever is moved in the transmission gear engagement position while the clutch-stroke-position learning is being carried out, the transmission gears will not be engaged. Thus, the vehicle would not start.
The interruption unit may include a sensor for detecting movements of the shift lever. This shift lever sensor may include a knob switch which is turned on in response to a predetermined intensity of force applied to the shift lever, a shift stroke sensor for detecting a shift stroke of the manual transmission, or a neutral switch for detecting if the manual transmission is in a neutral condition.
In the clutch-stroke-position learning, the starting position of the partly engaged condition of the clutch is preferably determined as follows: the clutch is automatically disengaged after predetermined study conditions are met, and then the clutch is automatically operated toward the engaged condition. When the rotational speed of an output element of the clutch reaches a prescribed value, the clutch stroke at that timing is taken as the start of the clutch partly engaged condition. It is also preferred that the automatic disengagement and engagement mechanism causes the clutch to automatically disengage after interruption of the clutch-stroke-position learning. Warning is preferably sent out as the clutch-stroke-position learning is stopped.
The clutch disengagement and engagement apparatus of the invention may further include a manual clutch disengagement and engagement device for effecting manual disengagement and engagement of the clutch in response to movements of a clutch pedal. This manual disengagement and engagement of the clutch is given priority over the automatic clutch disengagement and engagement. After interrupting the clutch-stroke-position learning, the automatic disengagement and engagement mechanism may automatically engage the clutch if the clutch pedal is stamped, whereas it may maintain the disengaged condition of the clutch if the clutch pedal is not stamped. This automatic clutch engagement may be performed at a relatively low speed.
REFERENCES:
patent: 4400997 (1983-08-01), Fiala
patent: 4582182 (1986-04-01), Takeda et al.
patent: 4629045 (1986-12-01), Kasai et al.
patent: 4926994 (1990-05-01), Koshizawa et al.
patent: 5014832 (1991-05-01), Satoh et al.
patent: 5029678 (1991-07-01), Koshizawa
patent: 5337874 (1994-08-01), Oltean et al.
patent: 5393274 (1995-02-01), Smedley
patent: 5626534 (1997-05-01), Ashley et al.
patent: 0 385 629 A2 (1990-09-01), None
patent: 0 441 290 A2 (1991-08-01), None
patent: 0 872 657 A1 (1998-10-01), None
patent: WO98/28162 (1998-07-01), None
Ishihara Masaki
Iwao Nobuyuki
Nishimura Nobuyuki
Sakai Nobutaka
Yamamoto Yasushi
Isuzu Motors Limited
Marmor Charles A
McCormick Paulding & Huber LLP
Rodriguez Saul
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