JP2013100843A - Transmission neutral position determining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission neutral position determining device that does not cause increase in manufacturing cost and complication of the configuration, and is improved in determination accuracy of the neutral position, even if upper and lower limit values of output voltage vary due to manufacturing variations or the like of a neutral sensor.SOLUTION: In the transmission neutral position determining device which compares an output voltage V of a neutral sensor attached to a part close to a shift member for moving a shift gear between a neutral positions and the like according to a driver' operation with a threshold VTH to determine whether the shift gear is in the neutral position, variation prediction values for an upper limit value and a lower limit value are obtained on the basis of sensor unique variation comprising manufacturing variation predicted for the neutral sensor, attachment variation, and deterioration due to environment and disturbance, and sensor output conversion variation including variation of operation voltage, and a threshold is set between corrected upper and lower limit values which are corrected by the predicted values.

Description

  The present invention relates to a transmission neutral position determination device, and more specifically, includes a transmission that connects and disconnects a clutch according to a clutch pedal operation by a driver, and whether or not a transmission gear is in a neutral position based on an output of a neutral sensor. The present invention relates to a device to be determined.

  A shift member that moves from the shift gear neutral position to the in-gear position according to the driver's shift lever operation is provided, and the output of the neutral sensor is compared with a threshold value to determine whether or not the shift gear is in the neutral position. The technique is known from the technique described in Patent Document 1, for example.

  The technique described in Patent Document 1 is configured to learn the sensor output at the neutral position of the shift lever, and to increase or decrease the determination region for each shift position accordingly.

  Further, as in the technique described in Patent Document 2, two neutral switches having the same structure are arranged in parallel in the transmission, and it is determined whether or not the outputs of the two coincide with each other to determine whether or not they are in the neutral position. It has also been proposed to determine.

JP 2001-173478 A JP 2008-302821

  By the way, in the neutral sensor, the upper and lower limit values of the output voltage vary due to manufacturing variations, mounting variations, deterioration due to environment and disturbance, etc., and the margin to be used for setting the threshold value between the upper and lower limit values is reduced. As a result, it cannot be determined with accuracy whether or not the sensor is in the neutral position.

  On the other hand, if the tolerance at the time of manufacture or attachment of the neutral sensor is set to be small, or if the sensor characteristic at the time of attachment is learned and corrected using the learning correction method described in Patent Document 1, the manufacturing cost increases. In addition, it is conceivable to double the sensors (switches) and monitor their outputs as in the technique described in Patent Document 2, but there is an inconvenience that an additional sensor is required and the configuration is complicated.

  Accordingly, the object of the present invention is to solve the above-mentioned problems, and even when the upper and lower limits of the output voltage vary due to manufacturing variations of the neutral sensor, the neutral cost is not increased and the configuration is not complicated. An object of the present invention is to provide a transmission neutral position determination device that improves the position determination accuracy.

  In order to solve the above-described problem, according to a first aspect of the present invention, an output of an engine mounted on a vehicle is shifted and transmitted to wheels, a transmission having a transmission gear, a drive shaft of the engine, and a transmission A mechanical friction clutch that is inserted between the machines and transmits the output of the engine to the transmission according to a driver's operation, and the transmission gear between a neutral position and an in-gear position according to a driver's operation. And an output voltage V corresponding to the distance from the shift member between the upper limit value and the lower limit value specified by the supplied operating voltage. The generated neutral sensor and the neutral sensor programmed to compare the output voltage V of the neutral sensor with a threshold value VTH to determine whether the transmission gear is in the neutral position. In a transmission neutral position determination device comprising an electronic control unit comprising a black computer, at least from manufacturing variations predicted for the neutral sensor, mounting variations to the part, and deterioration due to environment / disturbance occurring during a predetermined year Based on the sensor inherent variation and the sensor output conversion variation including at least the operating voltage variation, the upper limit value and the lower limit variation prediction value are obtained, and the correction upper limit value and the correction lower limit corrected by the obtained variation prediction value The threshold value is set between the values.

  In the transmission neutral position determination device according to claim 2, the sensor output conversion variation includes an AD conversion variation that is predicted to occur when the sensor output voltage V is converted into a digital value, and the operation voltage. It is configured to include at least one of electromagnetic wave noise predicted by the power supply line to be supplied.

  In the transmission neutral position determination device according to claim 3, the microcomputer of the electronic control unit may output the sensor output voltage V when the sensor output voltage V is between the upper limit value and the corrected upper limit value. When the upper limit value is between the lower limit value and the corrected lower limit value, the sensor output voltage V is programmed to be clamped to the lower limit value.

  In the transmission neutral position determination device according to claim 4, the sensor output conversion variation includes a variation when the sensor output voltage V is clamped to the upper limit value or the lower limit value.

  In claim 1, an upper limit value defined by an operating voltage that is attached to a portion in the vicinity of a shift member that moves the transmission gear between the neutral position and the in-gear position according to the operation of the driver, A neutral sensor that generates an output voltage V corresponding to the separation distance from the shift member between the lower limit values, and an electronic control that determines whether or not the transmission gear is in the neutral position by comparing the output voltage V with a threshold value VTH. In a transmission neutral position determination device comprising a unit, at least a sensor-specific variation and a variation in operating voltage, which are at least composed of manufacturing variation and mounting variation predicted for a neutral sensor, and deterioration due to environment and disturbance occurring during a predetermined year, are at least Based on the sensor output conversion variation including the upper limit value and the lower limit value, Since the threshold value is set between the correction upper limit value and the correction lower limit value corrected with the predicted value, the upper and lower limit values of the output voltage may vary due to manufacturing variations of the neutral sensor. By setting the threshold value between a correction upper limit value and a correction lower limit value that are corrected with the obtained variation predicted value, the accuracy of determining the neutral position, that is, the accuracy of determining whether or not the neutral position is reached is improved. Can do.

  In addition, since there is no need to change tolerances or make corrections to sensor characteristics during the manufacture of neutral sensors, there is no increase in manufacturing costs and the sensor is not duplicated. There is no inconvenience.

  Furthermore, by classifying and predicting sensor-specific variations such as manufacturing variations and sensor output conversion variations such as operating voltage, it is possible to obtain the predicted variation without any omission, and thus the correction that is corrected with the predicted value. It is possible to appropriately set a threshold value between the lower limit values, and it is possible to further improve the accuracy of determining whether or not the vehicle is in the neutral position.

  As a result, even when performing idling stop control, for example, it can be accurately determined whether or not it is in the neutral position, so that the engine can be properly stopped and restarted, and the fuel consumption can be reduced. Become.

  In the transmission neutral position determination device according to claim 2, the sensor output conversion variation is predicted to occur when the sensor output voltage V is converted into a digital value, and the power supply for supplying the operating voltage Since it is configured so as to include at least one of electromagnetic wave noise predicted by a line, in addition to the above-described effects, it is possible to obtain a variation predicted value without omission.

  In the transmission neutral position determination device according to claim 3, the microcomputer of the electronic control unit sets the lower limit value and the corrected lower limit value when the sensor output voltage V is between the upper limit value and the corrected upper limit value. Since it is configured to be programmed to clamp to the lower limit when it is between the values, in addition to the effects described above, management at the time of manufacture becomes easy. That is, since the upper limit value and the lower limit value of the output voltage V are fixed values, management at the time of manufacture becomes easy, and workability can be improved.

  Further, since the lower limit value is a value indicating the boundary where the transmission gear, more specifically, the dog tooth contacts the adjacent receiving side, it can be reliably determined whether or not it is in the neutral position.

  In the transmission neutral position determination device according to claim 4, the sensor output conversion variation includes a variation when clamping the sensor output voltage V to the upper limit value or the lower limit value, in other words, a shift member or the like. In addition to the effects described above, it is possible to more reliably determine whether or not it is in the neutral position.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing an overall transmission neutral position determination device according to an embodiment of the present invention. FIG. 2 is an explanatory side view of the shift mechanism shown in FIG. 1 as viewed from the shaft end of the input / output shaft of the transmission. FIG. 3 is an enlarged explanatory top view of the shift mechanism shown in FIG. 2. It is a block diagram which shows the structure of ECU as a transmission neutral position determination apparatus shown in FIG. It is explanatory drawing which shows the output voltage characteristic of the neutral sensor shown in FIG. 6 is a flowchart showing the operation of the ECU shown in FIG. It is explanatory drawing which shows the output voltage characteristic of the neutral sensor shown in FIG. 1, and is explanatory drawing which shows the characteristic of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment for carrying out a transmission neutral position determination device according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram showing the overall transmission neutral position determining apparatus according to an embodiment of the present invention.

  In the following description, reference numeral 10 denotes a manual transmission (hereinafter referred to as “transmission”) that receives the output of the engine (ENG) 12 and changes the speed and transmits it to the wheels 14. The transmission 10 has a transmission gear (speed stage) of 6 forward speeds and 1 reverse speed (RVS), that is, a transmission gear of forward n speed (n ≧ 2, specifically n = 6).

  The engine 12 is a spark ignition type internal combustion engine that uses gasoline as fuel, for example, and the output of the engine 12 is transmitted between the drive shaft (crankshaft) 12a of the engine 12 and the transmission 10 according to the operation of the driver. The mechanical friction clutch 16 which transmits to 10 is inserted. The engine 12 is mounted on a vehicle 18 partially indicated by wheels 14 or the like.

  A mechanical friction clutch (hereinafter referred to as “clutch”) 16 is a circular donut-shaped clutch disk (friction material) 16a that can contact a drive shaft 12a of the engine 12, more precisely, a flywheel 12b fixed to the drive shaft 12a. Clutch plate 16b affixed on the circumference, pressure plate (friction material) 16c having the same shape as the clutch disk 16a, disposed behind it (flywheel side), and a diaphragm-like spring disposed thereon 16d.

  The clutch disk 16a (and the pressure plate 16c) is fastened by being pressed against the flywheel 12b of the engine 12 by the spring 16d and transmits the output of the engine to the transmission 10.

  A clutch pedal 20 provided on the floor of the vehicle driver's seat so as to be operated by the driver is connected to the clutch 16 via a known master cylinder (hydraulic cylinder) 22 and a release cylinder 24 (hydraulic cylinder).

  The clutch pedal 20 is connected to a piston slidably accommodated inside the master cylinder 22 via a piston rod. The master cylinder 22 is connected to a release cylinder 24 through a pipe to supply and discharge hydraulic pressure. A piston is also slidably accommodated in the release cylinder 24.

  In the release cylinder 24, the piston includes a piston rod 24a, and the piston rod 24a is connected to a release fork 24b. The release fork 24b is connected to the spring 16d of the clutch 16 via a release pivot 24c fixed to the transmission case 10d.

  When the driver depresses (operates) the clutch pedal 20, the depressing force is transmitted as hydraulic pressure from the master cylinder 22 to the release cylinder 24, and the piston rod 24a of the release cylinder 24 strokes and releases the distance corresponding to the depressing amount. The fork 24b is driven in the front-rear direction.

  As shown in the figure, the release pivot 24c is disposed closer to the clutch 16 than the central position of the release fork 24b. Therefore, the movement of the release fork 24b using the release pivot 24c as a fulcrum is increased and transmitted to the spring 16d of the clutch 16, The spring 16d is pressed to drive the clutch 16 to the released position.

  On the other hand, when the driver removes his / her foot from the clutch pedal 20, the clutch 16 (the clutch plate 16b) moves to the fastening position where the drive shaft 12a of the engine 12 is transmitted by the urging force of the spring 16d.

  The transmission 10 is connected to a drive shaft 12 a of the engine 12 and inputs an output shaft (main shaft) 10 a for inputting the output of the engine 12, and is provided in parallel with the input shaft 10 a and an output shaft ( Counter shaft) 10b. The input shaft 10a and the output shaft 10b are rotatably supported by the transmission case 10d via bearings 10c.

  A first speed drive gear 10e, a second speed drive gear 10f, and an RVS (reverse drive) drive gear 10g are non-rotatably disposed on the input shaft 10a, and a third speed drive gear 10h and a fourth speed drive gear 10i are disposed on the output shaft 10b. And the 5th speed drive gear 10j and the 6th speed drive gear 10k are arrange | positioned so that rotation is impossible.

  The output shaft 10b is rotatably arranged with a first speed driven gear 10l meshed with the first speed drive gear 10e and a second speed driven gear 10m meshed with the second speed drive gear 10f, and the input shaft 10a is driven with a third speed drive. A third speed driven gear 10n that meshes with the gear 10h, a fourth speed driven gear 10o that meshes with the fourth speed drive gear 10i, a fifth speed driven gear 10p that meshes with the fifth speed drive gear 10j, and a sixth speed driven gear 10q that meshes with the sixth speed drive gear 10k. Arranged to be rotatable.

  Further, an RVS gear 10s that can mesh with the RVS drive gear 10g is disposed on the RVS shaft 10r so as not to rotate with respect to the RVS shaft 10r. A gear 10t is disposed on the output shaft 10b so as not to rotate with respect to the output shaft 10b.

  The gear 10t is connected to the differential mechanism 10v through the gear 10u. The differential mechanism 10v is connected to the wheel 14 via the drive shaft 10w.

  A 1-2 speed sleeve 10x, a 3-4 speed sleeve 10y, and a 5-6 speed sleeve 10z are arranged in the vicinity of the input shaft 10a and the output shaft 10b.

  On the other hand, a shift lever 26 is arranged in the vehicle driver's seat so that the driver can operate it. The shift lever 26 is configured to be movable in a shift pattern 26a defined by a shift arm, a shift piece (described later), and the like according to the operation of the driver.

  In the shift pattern 26a, the center positions n1, n2, and n3 of the 1-2, 3-4, and 5-6 speeds are in the neutral position N (the transmission gears such as the first speed drive gear 10e are both input shafts 10a and output shafts). 10b is a position that is not fixed (not in-gear).

  As shown in the figure, in this specification, the movement of the shift lever 26 toward either forward 1-6 speed or R is “shifted”, and the movement along the direction in which the neutral positions n1, n2, n3 are continuous is “ It is called “Select”.

  The shift lever 26 is mechanically connected to the above-described sleeves 10x, 10y, and 10z via the shift mechanism 30.

  2 is an explanatory side view of the shift mechanism 30 as viewed from the shaft ends of the input / output shafts 10a and 10b of the transmission 10, and FIG. 3 is an enlarged explanatory top view thereof. 2 and 3, illustration of the sleeves 10x, 10y, 10z, etc. shown in FIG. 1 is omitted.

  As shown in FIG. 2, the shift mechanism 30 is fixed to the shaft member 30a, the shift member 30a made of a magnetic material such as iron, a shift fork 30c, and a shift arm (shift member) 30b. A shift piece 30d (shown as 30d1, 30d2, etc.) for connecting a shift fork 30c (shown as 30c1, 30c2, etc.) is provided.

  The shift fork 30c includes a 1-2 speed shift fork 30c1 engaged with the 1-2 speed sleeve 10x, a 3-4 speed shift fork 30c2 engaged with the 3-4 speed sleeve 10y, and a 5-6 speed sleeve. 5-6 speed shift fork 30c3 engaged with 10z, and R shift fork 30c4 (not shown) engaged with RVS gear 10s. Four shift forks are collectively referred to as 30 cn.

  The shift piece 30d includes a plate-like member that is attached to a fork shaft 30e that passes through the shift fork 30c and is fixed to the shift fork 30c, and a 1-2 speed shift piece 30d1 that is attached to the 1-2 speed shift fork 30c1. 3-4 speed shift piece 30d2 attached to 3-4 speed shift fork 30c2, 5-6 speed shift piece 30d3 attached to 5-6 speed shift fork 30c3, and R shift piece 30d4 attached to R shift fork 30c4 Consists of. Four shift pieces are collectively referred to as 30 dn.

  As shown in FIG. 3, the other end sides of the four shift pieces 30dn each have an engaging portion 30dn1 formed in a spanner shape, and the engaging portion 30dn1 engages with the protrusion 30b1 of the shift arm 30b, and thus shifts. Any one of the corresponding sleeves 10x, 10y, and 10z is configured to be movable in the axial direction of the input shaft 10a or the output shaft 10b via the fork 30cn.

  The shaft member 30a has a long shaft 30a1, and the long shaft 30a1 is engaged with a link 30a2 connected to a shift lever 30 (not shown in FIG. 2 and the like) via a rod on one end side and moves in the axial direction (selection). And can be rotated (shifted) in the direction around the axis of the long axis 30a1 via a locking part 30a3 connected to the shift lever 26 with a wire.

  As shown in FIG. 2, the shift arm 30b has an axial thickness comparable to three of the four shift pieces 30dn, and a projection 30b1 having an axial thickness comparable to one.

  That is, in the shift mechanism 30, the shift arm 30 b is moved (selected) in the axial direction via the shaft member 30 a according to the movement of the shift lever 26 operated by the driver, and one of the four shift pieces 30 dn is selected. It is configured to always be engaged and to move (shift in) one shift piece engaged (moved) around the axis in the axial direction of the input shaft 10a or the output shaft 10b.

  When the driver depresses the clutch pedal 20 to operate the clutch 16 to the released position and to operate the shift lever 26, the sleeves 10x, 10y, and 10z are moved to the left and right in FIG. To shift the speed.

  For example, when the shift lever 26 is operated to the first speed position, the first-second gear sleeve 10x moves to the left in FIG. 1 to fix the first-speed driven gear 10l to the output shaft 10b.

  As a result, the first speed is established, and the output of the engine 12 is transmitted to the input shaft 10a via the clutch 16, and the first speed drive gear 10e, the first speed driven gear 10l, the output shaft 10b, the gear 10t, the gear 10u, and the differential mechanism. 10v, the drive shaft 10w, and the wheels 14 are transmitted to drive the vehicle in the forward direction.

  When the shift lever 26 is operated to the second speed position, the first and second speed sleeves 10x move right in FIG. 1 to fix the second speed driven gear 10m to the output shaft 10b. As a result, the second speed stage is established. The output is transmitted to the clutch 16, the input shaft 10a, the second speed drive gear 10f, the second speed driven gear 10m, the output shaft 10b, and the gear 10t.

  When the shift lever 26 is operated to the 3rd speed position, the 3-4 speed sleeve 10y moves to the left in FIG. 1 to fix the 3rd speed driven gear 10n to the input shaft 10a. As a result, the 3rd speed stage is established. The output is transmitted to the clutch 16, the input shaft 10a, the third speed driven gear 10n, the output shaft 10b, the third speed drive gear 10h, and the gear 10t.

  When the shift lever 26 is operated to the 4th speed position, the 3-4 speed sleeve 10y moves to the right in FIG. 1 to fix the 4th speed driven gear 10o to the input shaft 10a. As a result, the 4th speed stage is established. The output is transmitted to the clutch 16, the input shaft 10a, the fourth speed driven gear 10o, the fourth speed drive gear 10i, the output shaft 10b, and the gear 10t.

  When the shift lever 26 is operated to the fifth speed position, the 5-6 speed sleeve 10z moves to the left in FIG. 1 to fix the fifth speed driven gear 10p to the input shaft 10a. As a result, the fifth speed stage is established. The output is transmitted to the clutch 16, the input shaft 10a, the fifth speed driven gear 10p, the fifth speed drive gear 10j, the output shaft 10b, and the gear 10t.

  When the shift lever 26 is operated to the 6th speed position, the 5-6 speed sleeve 10z moves to the right in FIG. 1 to fix the 6th speed driven gear 10q to the input shaft 10a. As a result, the 6th speed stage is established. The output is transmitted to the clutch 16, the input shaft 10a, the sixth speed driven gear 10q, the sixth speed drive gear 10k, the output shaft 10b, and the gear 10t.

  When the shift lever 26 is operated to the R (RVS) position, the RVS gear 10s moves to the left in FIG. 1 and meshes with the RVS drive gear 10g. As a result, the first reverse speed is established, and the output of the engine 12 is the clutch 16 , Input shaft 10a, RVS drive gear 10g, RVS gear 10q, 1-2 speed sleeve 10x, output shaft 10b, gear 10t, gear 10u, differential mechanism 10v, drive shaft 10w, wheels 14 are transmitted to the vehicle in the reverse direction To run.

  Returning to the description of FIGS. 2 and 3, in the shift arm 30b, the second protrusions 30b2 having the same axial thickness as the four shift forks 30c are formed on the side opposite to the formation position of the protrusions 30b1. . Hereinafter, the second protrusion 30b2 is referred to as a “target”.

  In the vicinity of the target 30b2, a neutral sensor 32 is fixed to the transmission case 10d (not shown; the above-mentioned “part”), and is disposed inside the transmission case 10d so as to be exposed to MTF (transmission hydraulic fluid). . As well shown in FIG. 3, the shift arm 30b is configured to be rotatable about the long axis 30a1, and is configured so that a range of a predetermined angle (for example, about several degrees to the left and right from the center position) indicates the neutral position. .

  The neutral sensor 32 includes a Hall element that generates a Hall electromotive force proportional to the magnetic field, and generates an output corresponding to the movement of the target 30b2 due to the rotation of the shift arm 30b, in other words, the distance from the shift arm 30b.

  Returning to the description of FIG. 1, a clutch pedal switch 20 a is disposed in the vicinity of the clutch pedal 20 disposed on the driver's seat floor of the vehicle 18, and every time the driver operates (steps on) the clutch pedal 20. Output a signal.

  A brake switch 34a is arranged in the vicinity of the brake pedal 34 arranged alongside the clutch pedal 20 on the vehicle driver's floor and outputs a signal each time the driver steps on the brake pedal 34 (braking operation). In addition, an accelerator opening sensor 36a is disposed in the vicinity of the accelerator pedal 36 to generate an output indicating the accelerator opening according to the amount of depression of the accelerator pedal 36 by the driver.

  A first rotation speed sensor 40 is disposed in the vicinity of the input shaft 10a of the transmission 10 to generate an output indicating the rotation speed NM of the input shaft 10a, and a second rotation speed sensor 42 in the vicinity of the drive shaft 10w. Is arranged to generate an output indicating the rotational speed of the drive shaft 10w, that is, the vehicle speed.

  A crank angle sensor 44 is disposed in the vicinity of the drive shaft 12a of the engine 12 to generate an output indicating the rotational speed NE of the engine 12 through the position of a piston (not shown), and to the intake pipe (not shown). A pressure sensor 46 is disposed to produce an output indicative of the intake pipe absolute pressure PBA indicative of the load on the engine 12.

  The output of the sensor group described above is input to an ECU (Electronic Control Unit) 50. The ECU 50 includes a microcomputer including a CPU, a ROM, a RAM, an I / O, and the like.

  The ECU 50 controls operations such as fuel supply and ignition timing of the engine 12 based on outputs from the crank angle sensor 44, the absolute pressure sensor 46, etc., and the transmission gear is in the neutral position based on the output from the neutral sensor 32 described above. It also functions as a neutral position determination device for a transmission that determines whether or not.

  FIG. 4 is a block diagram showing a configuration of the ECU 50 as a transmission neutral position determination device.

  As described above, the ECU 50 includes the microcomputer 50a including the CPU 50a1, the ROM 50a2, the RAM 50a3, the I / O 50a4 and the like, and the A / D conversion circuit 50b. The output of the neutral sensor 32 is converted into a digital value by the A / D conversion circuit 50b. It is converted and stored in the RAM 40c via the I / O 50a4.

  The ECU 50 operates by being supplied with an operating voltage stepped down to 3.3 V via a wire (power supply line) 52a from a battery 52 (not shown in FIG. 1) having a rated output of 12 V mounted on the vehicle 18. The ECU 50 further includes a regulator 54, controls the operation of the regulator 54, reduces the voltage supplied from the battery 52 to 5 V, and supplies the voltage to the neutral sensor 32.

  FIG. 5 shows the output voltage characteristics of the neutral sensor 32. As shown in the figure, the neutral sensor 32 is essentially a target by rotation of the shift arm 30b between an upper limit value (for example, 4.5V) and a lower limit value (for example, 0.5V) defined by the supplied operating voltage 5V. An output voltage V corresponding to the distance from 30b2 is generated.

  FIG. 6 is a flowchart showing the neutral position determination operation of the ECU 50.

  In the following description, the output voltage V of the neutral sensor 32 is compared with the threshold value VTH in S10, and it is determined whether or not the output voltage V is equal to or higher than the threshold value VTH. 10f,. . Is determined to be in the neutral position, on the other hand, when the result is negative, the program proceeds to S14, in which it is determined that the transmission gear is in the in-gear position.

  Thus, the microcomputer 50a of the ECU 50 is programmed to compare the output voltage V of the neutral sensor 32 with the threshold value VTH to determine whether or not the transmission gear is in the neutral position.

  Here, to reexplain the problem of the present invention, the upper and lower limit values shown in FIG. 5 are actually varied due to manufacturing variations of the neutral sensor 32 and the like, and it cannot be accurately determined whether or not it is in the neutral position. . Therefore, the present invention improves the accuracy of determining whether or not the vehicle is in the neutral position without increasing the manufacturing cost and complicating the configuration even when the upper and lower limit values of the output voltage V vary. The object is to provide a neutral position determination device.

  From this intention, in this embodiment, as shown in FIG. 7, the manufacturing (shipment) variation predicted for the neutral sensor 32, the mounting variation to the transmission case (part) 10d, and a predetermined year (for example, 10 years). An upper limit value (for example, 4.5 V) and a lower limit value (for example, 0.5 V) based on sensor-specific variation including at least deterioration due to environment / disturbance that occurs during the period, and sensor output conversion variation including at least variation in operating voltage of 5 V ) Variation prediction values (a1 to a9 and b1 to b8 described later), and a correction upper limit value (shown as “A [V]” in FIG. 7) and a correction lower limit value (corrected with the calculated variation prediction values) The threshold value VTHR is set between “B [V]” in FIG.

  That is, the sensor specific variation includes manufacturing (shipment) variation, mounting variation, and deterioration due to environment / disturbance, and on the upper limit side, the manufacturing (shipment) variation is predicted to be ± a1.

  As the mounting variation, the variation in the air gap (the separation distance between the neutral sensor 32 and the target 30b2) is predicted as -a2, and the variation in the center shift (the mounting shift of the target 30b2 to the transmission case 10d) is predicted as -a3.

  As degradation due to environment / disturbance, variation caused by contamination over a predetermined year (for example, 10 years) due to iron powder mixed in the MTF is ± a4, the environmental temperature, that is, the MTF due to the outside air temperature where the vehicle 18 is located. The variation due to the change in viscosity is predicted as ± a5.

  The sensor output conversion variation is ± a6 as the variation in operation (supply) voltage when controlling the step-down of the regulator 54 of the ECU 50, and the neutral sensor 32 converted to a digital value via the A / D conversion circuit 50e of the ECU 50. ± a7 is predicted as variation when reading the output, and ± a8 is predicted as variation due to electromagnetic wave noise in the wire (power supply line) 52a.

  Further, as shown in FIG. 7, the ECU 50 sets the sensor output voltage V to the upper limit value when the sensor output voltage V is between the upper limit value and the corrected upper limit value, and the sensor output voltage V when the sensor output voltage V is between the lower limit value and the corrected lower limit value. The output voltage V is programmed to be clamped to the lower limit value, but the sensor output conversion variation includes a variation when the sensor output voltage V is clamped to the upper limit value or the lower limit value, and the value is predicted to be ± a9. . Note that the above-described upper limit side variations a1, a2, etc. are specifically indicated by the voltage V.

  Similarly, even on the lower limit side, each variation is predicted as b1 to b8. Similarly to the upper limit side variations a1, a2, etc., the lower limit side variations b1, b2, etc. are specifically indicated by the voltage V. Note that the variations b1 to b8 on the lower limit side are values relating to in-gear determination, and variations due to deviation of the sensor 32 from the center position of the target 30b2 (shown as center deviation in FIG. 7) do not occur.

  As described above, in this embodiment, the output of the engine 12 mounted on the vehicle 18 is shifted and transmitted to the wheels 14, and the transmission gears 10e, 10f,. . , A mechanical friction clutch 16 that is inserted between the drive shaft 12a of the engine 12 and the transmission 10 and transmits the output of the engine 12 to the transmission 10 according to a driver's operation. And a shift member (shift arm) 30b that moves the transmission gear between a neutral position and an in-gear position in accordance with the operation of the driver, and is attached to a portion near the shift member and is supplied with an operating voltage A neutral sensor 32 that generates an output voltage V corresponding to a separation distance from the shift member between a predetermined upper limit value and a lower limit value, and the output voltage V of the neutral sensor is compared with a threshold value VTH to change the speed change gear. ECU (electronic control unit) comprising a microcomputer 50a programmed to determine (detect) whether or not is in the neutral position 50, the sensor-specific variation including at least the manufacturing variation predicted for the neutral sensor 32, the mounting variation to the part, and the deterioration due to the environment / disturbance occurring during a predetermined year. Based on the sensor output conversion variation including at least the variation of the operating voltage, a variation predicted value of the upper limit value and the lower limit value is obtained, and the correction upper limit value and the correction lower limit value corrected by the calculated variation predicted value Since the threshold value is set, even when the upper and lower limit values of the output voltage V vary due to manufacturing variations of the neutral sensor 32, the threshold value VTHR is corrected with the obtained predicted variation value. By setting it between the upper limit value and the corrected lower limit value, the neutral position judgment accuracy, i.e. It is possible to improve the accuracy of determining whether in Le position.

  In addition, since it is not necessary to change tolerances at the time of manufacturing the neutral sensor 32 or to correct the learning of the sensor characteristics, the manufacturing cost is not increased and the sensor is not made a dual system. There is no complication.

  Furthermore, by classifying and predicting sensor-specific variations such as manufacturing variations and sensor output conversion variations such as operating voltage, it is possible to obtain the predicted variation without any omission, and thus the correction that is corrected with the predicted value. It is possible to appropriately set a threshold value between the lower limit values, and it is possible to further improve the accuracy of determining whether or not the vehicle is in the neutral position.

  As a result, even when performing idling stop control, for example, it can be accurately determined whether or not it is in the neutral position, so that the engine can be properly stopped and restarted, and the fuel consumption can be reduced. Become.

  In addition, the sensor output conversion variation is predicted to occur when the sensor output voltage V is converted into a digital value, and electromagnetic wave noise predicted by the power supply line (wire) 52a that supplies the operating voltage. In addition to the above-described effects, it is possible to obtain a predicted variation value without omission.

  Further, the microcomputer 50a of the ECU (electronic control unit) 50 sets the sensor output voltage V to the upper limit value and the lower limit value when the sensor output voltage V is between the upper limit value and the corrected upper limit value. Since the sensor output voltage V is programmed to be clamped to the lower limit value when it is between the corrected lower limit values, in addition to the above-described effects, management at the time of manufacture becomes easy. That is, since the upper limit value and the lower limit value of the output voltage V are fixed values, management at the time of manufacture becomes easy, and workability can be improved.

  Further, since the lower limit value is a value indicating the boundary where the transmission gear, more specifically, the dog tooth contacts the adjacent receiving side, it can be reliably determined whether or not it is in the neutral position.

  Further, the sensor output conversion variation is configured to include a variation when the sensor output voltage V is clamped to the upper limit value or the lower limit value, in other words, includes a tolerance variation of components such as a shift member. Therefore, in addition to the above-described effects, it can be more reliably determined whether or not it is in the neutral position.

  In this specification, it is sufficient that the transmission 10 includes the mechanical friction clutch 16, and therefore, the transmission 10 is not limited to the manual transmission, and the operation of the actuator is controlled according to the clutch pedal operation by the driver. Then, a transmission such as a CBW (Clutch by Wire) type in which the mechanical friction clutch 16 is connected / disconnected may be used.

  Moreover, although the neutral sensor 32 was comprised from the Hall sensor which applies a Hall effect, it is not restricted to it, The sensor which consists of another magnetoelectric conversion element may be sufficient.

  10 transmission (manual transmission), 10e first speed drive gear (transmission gear), 10f second speed drive gear (transmission gear),. . , 12 engine (internal combustion engine), 12a drive shaft, 14 wheels, 16 clutch (mechanical friction clutch), 16d spring, 18 vehicle, 20 clutch pedal, 20a clutch pedal stroke sensor, 22 master cylinder, 24 release cylinder, 24a piston Rod, 24b Release fork, 26 Shift lever, 30 Shift mechanism, 30a Shaft member, 30b Shift arm, 30b2 Second projection (target), 30c Shift fork, 32 Neutral sensor, 34 Brake pedal, 34a Brake switch, 36 Accelerator pedal 36a Accelerator opening sensor, 40, 42 Rotational speed sensor, 44 Crank angle sensor, 46 Absolute pressure sensor, 50 ECU (electronic control unit), 50a Microcomputer, 52 Battery, 52a wire (power line), 54 regulator

Claims (4)

  The engine mounted on the vehicle is changed in speed and transmitted to the wheels, and a transmission having a transmission gear is interposed between the drive shaft of the engine and the transmission, and the engine is operated according to a driver's operation. And a shift member that moves the transmission gear between a neutral position and an in-gear position according to a driver's operation, and a portion in the vicinity of the shift member. In addition, a neutral sensor that generates an output voltage V corresponding to a separation distance from the shift member between an upper limit value and a lower limit value defined by the supplied operating voltage, and an output voltage V of the neutral sensor is set to a threshold value VTH. An electronic control unit comprising a microcomputer programmed to determine whether the transmission gear is in a neutral position compared to In the transmission neutral position determination device, the sensor-specific variation and the variation in the operating voltage, which are at least composed of manufacturing variation predicted for the neutral sensor, attachment variation to the part, and deterioration due to environment / disturbance occurring during a predetermined year, Based on at least the sensor output conversion variation including the upper limit value and the lower limit variation prediction value, the threshold value is set between the correction upper limit value and the correction lower limit value corrected by the calculated variation prediction value. A transmission neutral position determination device characterized in that it is configured as described above.   The sensor output conversion variation is at least one of AD conversion variation predicted to occur when the sensor output voltage V is converted to a digital value, and electromagnetic wave noise predicted by a power supply line that supplies the operating voltage. The transmission neutral position determining apparatus according to claim 1, wherein   The microcomputer of the electronic control unit has the sensor output voltage V between the upper limit value and the lower limit value and the corrected lower limit value when the sensor output voltage V is between the upper limit value and the corrected upper limit value. 3. The transmission neutral position determination device according to claim 1, wherein the transmission neutral position determination device is programmed to clamp the sensor output voltage V to the lower limit value.   4. The transmission neutral position determination device according to claim 3, wherein the sensor output conversion variation includes variation when the sensor output voltage V is clamped to the upper limit value or the lower limit value.

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