JPS62216831A - Speed change control device for automatic transmission - Google Patents

Abstract

PURPOSE:To enable the optimum gear shift to be automatically selected in accordance with running resistance, by providing a running performance decision means, which decides the running resistance from a vehicle load, and performing a shift-up only when an engine output is larger than the running resistance. CONSTITUTION:A shift map 1 is for determining the optimum gear shift in accordance with a car speed and an accelerator opening, and a signal is fed to a control unit 2 from said shift map. The control unit 2 has a circuit, which calculates an engine output, while determines running resistance from a vehicle load signal. And the control unit, which compares the engine output with the running resistance, performs a shift-up to an expected gear shift in accordance with an ordinary logic when the engine output is larger than the running resistance. Reversely when the engine output is smaller than the running resistance, the shift-up is inhibited. In this way, when a vehicle is in climbing or the like, its running performance can be enhanced by suppressing a useless gear shift.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a speed change control device for an automatic transmission of an automatic transmission.

(Prior Art) The shift control logic of a conventional electronically controlled automatic transmission is based on the throttle opening (hereinafter referred to as Ci) based on the vehicle speed and the accelerator pedal depression 114 as shown in FIG. 4(a). The shift schedule is based on the accelerator opening (referred to as the accelerator opening). The figure is an example of a shift map, with the solid line showing the shift amplifier schedule for each gear stage, and the broken line showing the shift amplifier schedule.

(Problems to be Solved by the Invention) However, when the road gradient is not uniform and changes frequently, it is required to run the +'li vehicle with automatic gear change stably. For example, when pitching as shown in Fig. 4(b), there are repeated shifts, amplifiers, and downshifts, and especially in the case of large and small circles, there is a problem that it is not possible to pitch in the D range (automatic shift range). Ta.

In a conventional shift schedule configured with normal logic, when a change in driving conditions occurs (e.g., depression of the accelerator, a decrease in gear, or an increase in 1F speed, etc.), the gear that is scheduled to be shifted up to the first gear is changed. Even though there is no margin in the engine output, the shift is amplified, and therefore the ILF is shifted down due to the heavy low speed in the gear that has been shifted up, so shift I/amp and shift town are repeated frequently. This is because For this purpose, methods such as providing a separate manual transmission range and having the driver select the optimal gear have been adopted, but with this method, operations such as gear changes are cumbersome, and automatic transmissions
There was a problem in that the ν quality was completely lost.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a shift control device for an automatic transmission that can automatically select the optimum gear according to the running resistance of a vehicle and can prevent unnecessary and undesirable upshifts. be.

(Means for Solving the Problems) In order to achieve the above object l], the transmission control exterior of the present invention:! P
In L, the automatic transmission's gear change control exterior commands the optimum gear position using a shift map according to the vehicle speed and accelerator opening;
, a calculating means for calculating the engine output at the commanded gear stage, a driving performance determining means for determining the driving resistance from the heavy load, and +i? A comparison means for comparing the engine output resistance with the engine output resistance described in 7.j1. ．． The shift/amplification is performed only when the engine output specified in +ii+ is larger.

(Function) The speed change control device of the present invention uses a shift I schedule based on medium speed and accelerator opening in addition to the conventional normal logic of selecting a suitable gear stage. The system calculates the engine output at Supplementary l to judge
1 speed change control is performed by adding an IE term (Embodiment) FIG. 1 is a block diagram showing an example of a speed change control device of the present invention.

2 is a shift map for determining the optimum gear according to the 1311 degrees of the accelerator pedal, and the command signal from this shift map 1 is manually inputted to the control unit 2. The control unit 2 commands the optimum gear stage of the transmission 4 via the hydraulic actuator 3. The hydraulic actuator 3 is driven by the command signal, and the operating valves of the clutch and gear are controlled. This control unit 2 has an arithmetic circuit that calculates the engine output at the gear determined by the shift map 1 based on a calculation formula to be described later, and includes a rotation speed times the engine 5 times the same - 1 gear position signal, A flanch stroke signal, etc. is input.Furthermore, the running resistance is determined by a running performance determination map (31st ffl) that determines the running resistance from the input vehicle load signal.

It has a comparison circuit etc. that compares the engine output and this running resistance.

FIG. 2 is a flowchart showing an example of the shift control logic in the control unit 2 described above.

First of all, from the regular Logifuku! The optimum gear stage is determined from the shift schedule determined by the 1-work speed and the accelerator opening degree (step a).

In the gear selected by this normal logic, it is determined whether or not to shift up by one when the accelerator opening is decreased or when the IL speed is increased or decreased (step b). If this judgment is 1rNO,], then
The current gear selected by normal logic is maintained. −・
On the other hand, if the determination is ``YES'' or ``l'', the engine output at the gear stage to be shifted next is determined from the shift map recorded in the memory of the controller I/roll unit 2 (step C). Next, in step d), the obtained engine output is compared with the running resistance, and if the engine output is greater than the running resistance, the gear is shifted up to r-constant gear according to the normal logic.On the other hand, If the engine output at the gear for which the shift amplifier is scheduled is smaller than the running resistance when the same gear is not engaged, the shift amplifier is activated (step e), and the gear is maintained at the selected gear according to the normal logic.

Note that the running resistance is calculated using the following equation.

Here, Pmer: Engine output corresponding to running resistance number, ρme
: engine output, A : constant, vs: total engine exhaust -ji.

Enemy: Vehicle weight.

Length: Final ratio, R: Tire radius, 8Lti: L: Transmission gear ratio, 闢: Change state of engine speed during time Δ.

The determination correction for the upshift according to the present invention will be explained in more detail based on the driving performance diagram shown in FIG.

When a small circle runs at +iL speed v1 on a road with a slope of a% (point A), the running resistance is ra, and under this condition the vehicle runs in the 4th gear selected by normal logic. It is assumed that If you reduce the accelerator opening while driving at this vehicle speed v1, or if the vehicle speed increases, should you still drive in 4th gear or shift up to 5th gear?
Judging whether it is better to drive at a higher speed is determined by the maximum engine output Pa' (the actual maximum engine output minus the margin engine output) at the scheduled 5th gear and the 1 running resistance r.
This is done by comparing the size with a. In this case, since P a ′ > r a, it is possible to drive at vehicle speed v1 even if the vehicle is shifted up to 5th gear, and since this will shorten the pitching time, the vehicle will be shifted up to 5th gear. Ru.

On the other hand, when a vehicle runs at vehicle speed v2 on a road with a slope of b% (point B), the running resistance is rb, and under this condition the vehicle runs in the third gear selected by normal logic. It is assumed that The judgment as to whether the two cars should still be running in 3rd gear or should be shifted up to 4th gear is made by comparing the maximum engine output Pb' in 4th gear with the running resistance rb. If P
Since b'<rb, upshifting is prohibited and 3rd gear is still maintained.

(Effects of the Invention) According to the shift control device of the present invention, it is possible to determine whether or not to perform shift amplification by comparing the magnitude of engine output and running resistance at the gear stage where shift amplification is planned. Since the gear is shifted up only when the gear is in a large S position, meaningless gear shifts such as upshifting that would normally occur in the conventional logic and downshifting that inevitably occurs as a result of the upshifting are suppressed. , it is possible to improve the running performance of the vehicle. In addition, by taking advantage of the automatic transmission,
Since the optimal gear stage can be selected, it is also possible to shorten the pitching time.

[Brief explanation of drawings]

FIG. 1 shows a blower 7 showing an example of the speed change control device of the present invention.
FIG. 2 is a flowchart showing an example of shift control in the device according to the embodiment, FIG. 3 is a driving performance diagram for explaining the shift control logic of the present invention, and FIG. , a diagram showing a shift schedule map, FIG. 4(b)
FIG. 2 is a diagram showing the state of a vehicle in a case where the road gradient is not uniform. 1... Shift map, 2... Control unit, 3... Hydraulic actuator, 4... Transmission, 5
...Taken to the engine 11 solution GL1 drawing Masashi Itouri Neho (self-motivated) March 6, 1985 Patent application No. 059013 2, title of invention Shift control device for automatic transmission 3 Correction Patent applicant address: 6-22-10, Minami-Oi, Tokyo Parts Store Name: Isu-X Jibokusha Co., Ltd. p4, Agent address: 3-145 Kanda Ogawamachi, Chiyoda-ku, Tokyo LO1
, Date of amendment order (voluntary) `` Full text of the specification to be amended and Drawing 7, Contents of amendment (1) The entire specification is amended as shown in the attached document. Description 1/Name of invention Speed change of automatic transmission Control device 2, Claims: A shift control device for an automatic transmission that commands an optimum gear position based on a shift map according to vehicle speed and accelerator opening,
a calculation means for calculating the engine output at the commanded gear stage; a calculation means for calculating running resistance from the vehicle load;
Comparison means for comparing the engine output and running resistance;
A shift control device for an automatic transmission, comprising means for prohibiting upshifting to the optimum gear when the running resistance is greater than the engine output as a result of the comparison by the comparison means. 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a shift control device for an automatic transmission of an automobile. (Prior Art) The logic of shift control &U of a conventional electronically controlled automatic transmission is based on the throttle opening (hereinafter simply referred to as accelerator opening) based on the vehicle speed and the amount of depression of the accelerator pedal, as shown in Fig. 4(a). The shift schedule is based on the shift schedule established by the company. The figure is an example of a shift map, with the solid line showing the shift 1-up schedule for each gear, and the broken line showing the shift down schedule. (Problem to be Solved by the Invention) However, when the road slope is not uniform and changes frequently, for example, when climbing a hill as shown in FIG. is repeated,
Particularly in the case of large vehicles, there was a problem that the D range (automatic shift range) could not be used. In other words, in a conventional shift schedule configured with normal logic, when a change in driving conditions occurs (for example, a decrease in the amount of accelerator pedal depression or an increase in vehicle speed), the shift schedule is changed to the next gear to be shifted up. Even though there is not enough engine output to spare, the gear is shifted up based on the shift map. Therefore, there is no margin in the engine output at the gear that has been shifted up, so the vehicle speed decreases and the gear is shifted down again, resulting in frequent repetition of upshifting and downshifting. For this,
Methods such as setting up a separate manual range and letting the driver select the optimal gear have been adopted, but with this method, operations such as changing gears are cumbersome and the characteristics of an automatic transmission are completely lost. There was a problem. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a shift control device for an automatic transmission that can automatically select an optimal gear depending on the running resistance of a vehicle and prevent inappropriate upshifts. (Means for Solving the Problems) In order to achieve the above object, the speed change control device of the present invention includes:
In a shift control device for an automatic transmission that commands an optimum gear position using a shift map according to vehicle speed and accelerator opening degree, a calculation means calculates an engine output at the commanded gear position and a running resistance is calculated from a vehicle load. comprising a calculating means, a comparing means for comparing the engine output and the running resistance, and a means for prohibiting upshifting to the gear when the running resistance as a result of the comparison by the comparing means is larger than the engine output; The shift-up is performed only when the engine output is greater. (Function) In addition to the conventional normal logic of selecting the optimum gear position based on a shift schedule based on vehicle speed and accelerator opening, the shift control device of the present invention calculates the engine output at the gear position scheduled for upshifting. , we have a logic that compares this carrot output and running resistance and shifts up only when the engine output is greater, and adds a correction term to determine whether to shift up according to running resistance to control the gear shift. ing. (Example) Fig. 1 shows an example of the speed change control device of the present invention.
The force M-shift 1 is a shift map for determining the optimum gear based on the vehicle speed and the accelerator opening, and a command signal from this shift map 1 is input to the control unit 2. The control unit 2 issues a shift command signal to, for example, a hydraulic actuator 3 that performs shift control of the transmission 4 based on a command signal from the shift map 1, and also outputs a control signal to a clutch actuator that operates a clutch (not shown). This control unit 2 has a calculation circuit that calculates the engine output at the gear determined by the shift map 1 based on a calculation formula described later, and includes a rotation speed signal of the engine 5, a gear position signal, a clutch stroke signal, etc. is entered. The control unit 2 also includes an arithmetic circuit that calculates running resistance from an input vehicle load signal, and a comparison circuit t that compares the engine output with this running resistance. It is a flowchart showing an example of the shift control logic in unit 2. First, from the normal logic, the optimum gear is determined from the shift schedule determined by the vehicle speed and the accelerator opening (step a). It is determined whether the selected gear is a shift-up shift relative to the current gear (step b). If this determination is rNOJ, the current gear selected by the normal logic is maintained. On the other hand, if the determination is rYEsJ, the engine output at the next gear to be shifted up is determined from the shift map stored in the memory of the control unit 2 (step C). In step d), the engine power output and the running resistance are compared, and if the engine power is greater than the running resistance, the gear is shifted up to the scheduled gear according to normal logic. On the other hand, if the engine output at the gear scheduled for upshifting is smaller than the running resistance at the same gear, upshifting is prohibited (step e
), the selected gear is maintained according to normal logic. Note that the running resistance is calculated using the following formula. Pmer-Pme-A X-'X('-)'X (1
) 2 to base Vs voice F ltc lt where, Pmer: Engine output corresponding to running resistance, Pme
: Engine output, A : Constant, Vs ・Total engine displacement, W : Vehicle weight, μf : Final ratio, R : Tire radius, μm1 Nidor transmission gear ratio, IK : Engine speed during time Δ The amount of change is t. The above shift-up determination correction according to the present invention will be explained in more detail based on the driving performance diagram of FIG. 3. When a vehicle travels at a vehicle speed v1 on a road with a slope of a% (
It is assumed that the running resistance at point A) is ra, and under this condition the vehicle is running in the 4th gear selected by normal logic. If the accelerator opening degree is decreased while the vehicle is running at a vehicle speed of 1, or if the speed increases by 1, it is determined whether the vehicle should still be driven in 4th gear or whether it is better to shift up and drive in 5th gear. 5 is scheduled to shift up.
maximum engine output Pa' (the value obtained by subtracting the margin engine output from the actual maximum engine output) and the running resistance ra.
This is done by comparing the size with In this case, since Pa'>ra, it is possible to drive at the vehicle speed Vl even if the vehicle is shifted up to the 5th gear, and since this will shorten the driving time, the vehicle is shifted up to the 5th gear. On the other hand, when a vehicle runs at vehicle speed v2 on a road with a slope of b% (point B), the running resistance is rb, and under this condition the vehicle runs in the third gear selected by normal logic. It is assumed that Determining whether this vehicle should still run in 3rd gear or shift up to 4th gear is 4.
This is done by comparing the maximum engine output pb' at the same speed with the running resistance rb; in this case, Pb'
<rb, so upshifting is prohibited and still
1 pu tsu : 士 I s, lt +± -1 ↓, ff (Effect of the invention) According to the shift control device of the present invention, the determination as to whether or not to shift up is made based on the gear position at which the upshift is scheduled. The engine output and running resistance are compared, and when the running resistance is greater than the engine output, shifting up to the optimum gear is prohibited, and only when the engine output is greater than the running resistance, the optimum gear is shifted. is shifted up to. Therefore, when the vehicle is on the road, the conventional normal logic prevents meaningless shifts in which upshifts and downshifts that inevitably occur as a result of a decrease in vehicle speed are frequently repeated, thereby improving the driving performance of the vehicle. In addition, it is possible to shorten the time required to take advantage of automatic transmissions by selecting the optimal gear. 4. Brief description of the drawings Fig. 1 is a block diagram showing an example of a shift control device for an automatic transmission of the present invention, Fig. 2 is a flowchart showing an example of shift control in the same embodiment device, and Fig. 3 is a block diagram showing an example of a shift control device for an automatic transmission according to the present invention. Car fun A+l plaster 1 collection 1
Figure 4 (a) shows the shift schedule map, Figure 4 (b) shows the performance curve of the vehicle on the road when the road gradient is not uniform. It is a figure showing a state. 1... Shift map, 2... Control unit, 3... Hydraulic actuator, 4... Transmission, 5
···engine. Patent applicant: Isu-X Jikokusha Co., Ltd.
People Patent Attorney Minoru Tsuji Figure 2

Claims (1)

[Claims] In automatic transmission shift control devices that command the optimal gear position using a shift map according to vehicle speed and accelerator opening,
The engine comprises a calculating means for calculating the engine output at the commanded gear stage, a driving performance determining means for determining the running resistance from the vehicle load, and a comparing means for comparing the engine output and the running resistance. A shift control device for an automatic transmission characterized by shifting up only when the output is greater.