JPS6115301B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an overdrive control device that automatically switches a transmission gear to overdrive in response to the running speed and engine load of a vehicle such as an automobile. Conventionally, in automatic transmission control devices with three-speed overdrive for regular automobiles, which are automatic transmission control devices used in automobiles, a shift point is set in advance based on the detection of the traveling speed (vehicle speed) and the detection of the engine load. (line), that is, depending on the vehicle speed and load, for 1st gear, 2nd gear in a multi-gear transmission,
The commanded gear among the 3rd speed and overdrive gears and the gear on the engine side are connected by a fluid joint called a so-called fluid torque converter, and a manual switch is required only for overdrive. It is built into the ment panel, and only when this switch is turned on will the overdrive gear be engaged, but when it is off, it will be engaged up to 3rd gear but will not be in the overdrive gear. It is designed not to enter. Then, shift from 1st gear to 2nd gear, 2nd gear to 3rd gear, or 3rd gear to overdrive, then reverse from 2nd gear to 1st gear, 3rd gear to 2nd gear,
When shifting from overdrive to 3rd gear, in order to prevent hunting at those shift points, there is a point where you shift to the next higher gear, that is, a point where you shift up, and a point where you shift to a gear one step lower, that is, a point where you shift down. Set a constant vehicle speed range for each,
That is, hysteresis is provided. This device has a shift point that improves fuel efficiency when driving on flat roads, so there is no problem with it, but when driving on slopes with slopes above a certain value, it is better to drive in 3rd gear rather than overdrive. Although the fuel efficiency, drivability, and acceleration performance are good, the above-mentioned shift point is set to improve fuel efficiency on flat roads, so there is no need to downshift to 3rd gear from overdrive, resulting in improved fuel efficiency. , have to drive in a pattern with poor drivability and acceleration performance.
Another disadvantage is that on downhill roads, overdrive has almost no engine braking effect, making it unsuitable for safe driving. As a countermeasure, it is necessary to turn on and off the manual overdrive switch every time the vehicle climbs or descends a slope, which is cumbersome and not desirable from a safety standpoint. The present invention solves the above problem by detecting the running acceleration of the vehicle and the intake negative pressure of the engine, and periodically determining whether an uphill road or a downhill road has a slope of a predetermined level or higher based on both detection signals. , by releasing the overdrive of the transmission.
It is an object of the present invention to provide an overdrive control device that can improve drivability on uphill and downhill roads, and that can contribute to ensuring safe driving by eliminating the need for special operations by the driver. It is something. The present invention will be described below with reference to embodiments shown in the drawings. In Figure 1, which shows the overall schematic configuration, 10
20 is a throttle switch that detects the throttle opening in multiple stages; 30 is a shift position switch attached to the shift lever; Neutral N, Drive D,
It has 6 positions: 2nd 2nd and 1st L ranges. Reference numeral 40 denotes a solenoid valve unit for shifting, which includes solenoids for controlling each of the three speed shifts, as well as an overdrive solenoid 41 for controlling shifting to overdrive. 50
is an overdrive switch, located on the instrument panel. Reference numeral 60 denotes a gradient detector that detects the gradient of the road surface on which the automobile is traveling; and 70, a shift control circuit that receives various signals and generates a drive signal to drive the solenoid valve unit 40 at a predetermined shift point, thereby automatically shifting gears. It has an overdrive release circuit 80 in addition to its transmission system. In the above overall configuration, the gradient detector 6
The automatic shift control system excluding the 0 and overdrive release circuit 80 is the one known in Japanese Patent Publication No. 47-51615 ``Automatic shift control device for automobiles'', with the addition of an automatic shift gear for overdrive. The overdrive system is also known in the magazine "Automotive Technology" Vol. 32, No. 7, 1978, pages 710 to 714. Next, the operation of the above configuration will be explained. This car now has a gear position switch of 30.
When driving on a flat road with the engine in the D range, the slope detection signal from the slope detector 60 is not generated, so the vehicle speed detected by the rotation speed detector 10 and the throttle switch 20 Based on the throttle opening detected by the speed change control circuit 7.
A predetermined shift point of 0 is determined, and a drive signal of a shift command corresponding to the operating state is applied to the solenoid valve unit 40, and the vehicle runs at an appropriate shift position. Therefore, once the vehicle starts from a stopped state,
Normally, the gears are shifted sequentially from 1st gear to 2nd gear to 3rd gear, and stable gear change control is performed in response to the load. When entering a relatively high speed range with the overdrive switch 50 closed, an overdrive control signal is applied from the shift control circuit 70 to the overdrive solenoid 41, which is energized and shifts to overdrive state driving. do. During this run, when we reached an uphill road, the slope detector 6
When the slope detection signal is generated from 0, the overdrive release circuit 80 de-energizes the overdrive solenoid 41, so that the solenoid valve unit 40 enters the overdrive release state. Therefore, on this uphill road, the vehicle travels with the gears changed from 1st to 3rd gear. Also, when approaching a downhill road, if a slope detection signal is generated from the slope detector 60 in the same way as on the above-mentioned uphill road, the speed will change from 1st gear to 3rd gear when traveling on that downhill road.
The vehicle travels by changing gears up to the speed position. On the other hand, when the driver manually releases the overdrive switch 50, the power to the overdrive solenoid 41 is forcibly cut off, and the overdrive is forcibly released. In this way, when driving on a flat road or the like where the slope detection signal is not generated by the slope detector 60, overdrive is utilized to improve fuel efficiency, reduce noise, etc., and the slope detector 6
On uphill or downhill roads where a slope detection signal is generated from 0, overdrive is automatically released, eliminating the need for special operations by the driver and improving drivability on the uphill or downhill roads. It is possible to achieve improvement and ensure safe driving. Next, the detailed configuration of the main parts in FIG. 1 will be sequentially explained. First, the gradient detector 60 will be explained with reference to the schematic diagram of FIG. 2. 100 is a reference clock unit that generates clock pulses of a constant frequency using a tuning fork vibrator; 200;
300 is a vehicle speed detection section; 400 is an acceleration detection section that receives the output of the vehicle speed detection section and detects the acceleration/deceleration of the vehicle; and 500 is a timing signal generation section that operates each part in an appropriate sequence. A negative pressure detection section including a diaphragm type semiconductor negative pressure sensor to be measured; 600 a brake detection section that detects whether the brake switch is ON; 700 a gradient determination section that determines the gradient based on the signals from the acceleration detection section 400 and the negative pressure detection section 500; It is a vessel. Next, gradient detection using this configuration will be described. First, pay attention to the following points when driving downhill.
That is, (A) Accelerates even though the throttle valve is closed. On a normal flat road, if the throttle valve is closed, the engine brake will be effective and the above condition (A) will not occur. However, on a downhill slope, potential energy is converted to kinetic energy, so the above phenomenon (A) occurs. If the throttle valve is closed, the negative pressure inside the intake manifold will increase, so the above state (A) can be replaced as follows. (a) Negative pressure is large despite acceleration. Applying the same idea to driving uphill: (B) The throttle valve decelerates even though it is opened beyond a certain degree. If the engine is replaced with negative pressure, the result will be as follows. (b) Negative pressure is small despite deceleration. Using these conditions (a) and (b), it is possible to determine whether the vehicle is traveling uphill or downhill. Regarding the magnitude of the slope, in (a), if the acceleration is large and the negative pressure is large, it is a steep descent and the acceleration is not very large, and if the negative pressure is not very large, it is determined to be a gentle downhill slope. In the case of (b), it is determined that the higher the deceleration and the lower the negative pressure, the steeper the uphill slope.If the deceleration is not too large and the negative pressure is not too small, it is determined that the uphill slope is gentle. An example of the judgment conditions obtained through experiments is shown in the discrimination table.

[Table] In the above discrimination table, the vehicle speed condition is usually 50km/h or more when shifting up from 3rd gear to overdrive gear, and when downshifting to 3rd gear it is around 30km/h. This is because The 30km/h speed is set to prevent malfunctions when starting, and the 50km/h speed is set to prevent overdrive from turning on and off frequently in mountainous areas.
It has been established with the aim of preventing this from occurring. Furthermore, each part in FIG. 2 will be explained in more detail. FIG. 3 shows a reference clock section 100 and a timing signal generating section 200. Reference clock section 100
consists of a tuning fork oscillation circuit 101, a frequency dividing circuit 102, and a power reset circuit 103. Tuning fork oscillation circuit 10
1 is a tuning fork vibrator 101a, an inverter 101b,
Consists of 101c and some resistors and capacitors,
A 2048Hz clock signal CL3 is obtained at its output. The frequency dividing circuit 102 includes a counter 102a, NAND gates, 102b, 102c, and an inverter 10.
Consists of 2d. The 2048Hz clock signal CL3 applied to the counter 102a counts 5792 pulses, that is, 5792/2048÷2.83sec, and the 6th, 8th, 10th, 11th, and 13th stages "Q ₆ ", "Q ₃ " ，
Since "Q ₁₀ ", "Q ₁₁ ", and "Q ₁₃ " are all at the "1" level, the output of the 5-input NAND gate 102b is at the "0" level, and therefore the output of the NAND gate 102c is at the "1" level. Power reset circuit 1
03, a short "1" level pulse is generated at the output of the inverter 103a when the power is turned on, but it continues to be "0" level thereafter. The timing signal generator 200 is a decimal counter 2
01, an RS flip-flop 202 consisting of two NOR gates, an inverter 203, and a NOR gate 204. The reference clock section 10
When a "1" level signal is input from the 0 NAND gate 102c to the clock terminal "C" of the decimal counter 201, the decimal counter 201 becomes ready for counting, and the clock input enable terminal "E"
Counts the clock signal CL3 input from
A "1" level pulse is output in the order of the first to fourth stages "Q ₁ ", "Q ₂ ", "Q ₃ ", and "Q ₄ ". The fourth
When the stage “Q ₄ ” goes to the “1” level, the RS flip-flop 202 is triggered and the set signal is
RS2 is generated, the counter 102a and the decimal counter 201 are both reset, the series of operations is completed, and the same operation is repeated again 2.83 seconds later. The i terminal has a constant vehicle speed (approximately 130 km/h)
h), a “1” level signal is input,
Prevents generation of CL2 signal. FIG. 4 shows a vehicle speed detection section 300 and an acceleration detection section 40.
Indicates 0. The vehicle speed detection unit 300 includes a vehicle speed sensor 301 that generates 4 pulses per revolution of the speedometer cable shaft, a waveform shaping circuit 302, and a vehicle speed detection circuit 3.
Consists of 03. A pulse generated by the vehicle speed sensor 301 is shaped by a waveform shaping circuit 302 and applied to a vehicle speed detection circuit 303. The vehicle speed detection circuit 303 is 2
Consisting of a binary counter 303a and two RS flip-flops 303b and 303c, the binary counter 303a counts vehicle speed pulses during pulses RS2 at 2.83 sec intervals emitted from the timing signal generator 200, and when the vehicle speed is approximately 30 km/h or more. “1” in V _ON
When the level signal is 50Km/h or more, a "1" level signal is output to V _OFF . Also, the vehicle speed is approximately 130km/
When it is equal to or higher than h, a "1" level signal is issued to the i terminal. The acceleration detection section 400 includes a pseudo differentiation circuit 401 and an acceleration setting circuit 402. Pseudo differential circuit 4
01 is a presettable up-down counter 40
1a, 401b, and a D flip-flop 401c, the contents of the binary counter 303a of the vehicle speed detecting section 300 are preset into the presettable up/down counters 401a, 401b by the preset signal P of the timing signal generating section 200, and the contents of the binary counter 303a of the vehicle speed detecting section 300 are preset to The vehicle speed pulse is used to count down from the preset value during the next vehicle speed measurement period of 2.83 seconds. Here, depending on the vehicle speed measured during the previous 2.83 seconds, that is, the vehicle speed currently preset, and the vehicle speed measured during the next 2.83 seconds, if the vehicle speed measured during the next 2.83 seconds is If it is large, that is, if it is accelerating, then this
Since the vehicle speed pulse for 2.83 seconds is greater than the preset value, the values of the presettable up-down counters 401a, 401b become zero, and at this time, the D flip-flop 401c is triggered and the presettable up-down counters 401a, 401b become zero.
401b is an up count. Then, the increase is counted for the greater vehicle speed. Also, if the vehicle speed measured during the next 2.83 seconds is smaller, the D flip-flop 401c will not be triggered and only the larger preset value will remain in the counter. By repeating this operation every 2.83 seconds, the presettable up-down counters 401a, 4
The outputs Q1, 2, 3, and 4 of D flip-flop 401b have a velocity difference every 2.83 seconds, that is, a pseudo velocity differential value - acceleration.
You can get the positive and negative acceleration. The magnitude of acceleration is determined by a presettable up-down counter 401.
0.005G per minimum bit of a
(1/(2.83) ² ×9.8×2.548≒0.005)
It is. FIG. 5 shows a negative pressure detection section 500 and a brake detection section 6.
Indicates 00. The negative pressure detection section 500 is a negative pressure sensor 50
1. Differential amplifier 502, comparator circuit 50
3. Consists of a time limit circuit 504. The diaphragm type semiconductor negative pressure sensor 501 generates a voltage proportional to the intake pipe negative pressure. The differential amplifier 502 receives this output, amplifies it to an appropriate size, and sends it to the comparator circuit 5.
Add to 03. 503a and 503b are potentiometers, which adjust the voltages to correspond to -100 mmHg and -380 mmHg shown above. If the output of differential amplifier 502 is greater than -100mmHg, comparator 5
The output of inverter 503c becomes "1" level, and therefore the output of inverter 503e becomes "0" level. When the intake pipe negative pressure is -100mmHg≦P≦-380mmHg, both outputs of comparators 503c and 503d are at “0” level, and therefore inverters 503e and 50
Both outputs of 3f are at the "1" level. -380mm
If it is smaller than Hg, the output of the comparator 503d becomes "1" level, and therefore the inverter 503d
The output of 03f becomes "0" level. Light emitting diodes 503g and 503h are potentiometers 50
This is an indicator when adjusting 3a and 503b, and is not related to the essential operation. Inverter 503
The outputs of e and 503f are input to the reset terminals of counters 504a and 504b of time limit circuit 504. This time limit circuit 504 outputs a "1" level signal to the P _L and P _N terminals when the intake pipe negative pressure becomes -100 mmHg or more or -380 mmHg or less for a certain time period (2 seconds) or more. This is to ensure operation. The brake detection section 600 detects the brake switch.
It takes an ON signal as input, and consists of a waveform shaping circuit 601 and a time limit circuit 602, and when the brake is turned ON for a certain period of time (1 sec) or more, it issues a "1" level signal to the BR terminal. FIG. 6 shows the slope determination section 700,
AND circuit 701, ON circuit 702, OFF circuit 70
3. Consists of an output circuit 704. AND circuit 701
When the logical product of (Vo _N・DEC・P _L ) is established, the output of the inverter 701a becomes “1” level, and when the logical value of (Vo _N・INC・P _H ) is established, the output of the inverter 701b becomes “1” level. 1” level, and when the AND of (Vo _FF.H・_L ) is established, the AND gate 701 is passed through the NOR gate 701c _.
The output of d becomes "1" level. (Vo _N・DEC・
When P _L ) holds, it is an uphill slope.
When (Vo _N・INC・P _H ) holds true, it means that the vehicle is traveling downhill, and when (Vo _FF・_H・_L ) holds true, it means that the vehicle is running on flat ground. The ON circuit 702 includes counters 702a, 702c and a NAND gate 70.
2b, 702d, 702e, and 702f, and when the "1" level signal of the inverter 701a continues for two periods (2.83 seconds x 2) of CL2 or more, the output of the NAND gate 722 becomes "0", and therefore the NAND gate The output of 702f becomes "1" level. Similarly, if the "1" level signal of the inverter 701b continues for two or more periods of CL2, the output of the NAND gate 702f becomes the "1" level. Furthermore, if the BR reaches the "1" level when the "1" level of the inverter 701b continues for one cycle or more, the output of the NAND gate 702f becomes the "1" level even if it does not continue for two cycles. The OFF circuit 703 includes a counter 703a, a NAND gate 703b, and an inverter 7.
03c, and the AND gate 701d
If the "1" level signal continues for two or more periods of CL2, the output of the inverter 703c becomes "1" level. The output circuit 704 is a D flip-flop 70.
4a and an OR gate 704b, the D flip-flop 704a is triggered by the "1" level signal of the NAND gate 702f of the ON circuit 702, and its output Q terminal becomes "1" level.
“1” of inverter 703c of OFF circuit 703
It is reset by a level signal, and its output Q terminal becomes "0" level. According to the above explanation, when the ON condition of the discriminant table is satisfied, the OUT terminal of the output circuit becomes a "1" level, and when the OFF condition is satisfied, it becomes a "0" level. FIG. 7 shows an overdrive release circuit 80, and if the vehicle is currently being driven in an overdrive state, the overdrive solenoid 41 is energized through the vehicle battery 801, IG switch 802, fuse 803, and normally closed relay 83 of the circuit 80. ing. Then, when approaching a slope, the slope detector 6
When the OUT terminal of 0 becomes “1” level, circuit 8
0 transistors 81 and 82 are reversed from OFF to ON, and the normally closed relay 83 becomes open. As a result, the energization of the overdrive solenoid 41 is cut off, and the overdrive is released. On the other hand, when the vehicle shifts to steady running on the flat ground, the OUT terminal of the slope detector 60 goes to the "0" level, so the overdrive state is restored again. Therefore, even if the vehicle is running in an overdrive state, if the slope detector 60 determines that the vehicle is going uphill or downhill by a certain value or more, the overdrive is automatically released, and when the vehicle returns to flat ground, the overdrive state is automatically activated. Return. Next, another embodiment of the present invention will be described with reference to FIGS. 8 and 9. FIGS. 8 and 9 show the configuration of the main parts, and are designed to detect intake negative pressure suitable for digital processing. In the boost pressure switch shown in Fig. 8, 901 is a pipe with an adjusting screw, and a rubber pipe for guiding intake negative pressure is attached to the tip of the pipe, and a nut 9 is attached to the adjusting screw part.
I am wearing 02. The other end of this pipe 901 is fixed to a housing 903, and the fixed portion is sealed with an O-ring 904. Also,
Inside this housing 903 is an air chamber 905.
A diaphragm 907 is further pressed by a spring 906. An insulating plate 908 is screwed to the other end of the housing 903, and an A contact 91 is located at a position opposite to a B contact 909 provided at the center of the diaphragm 907.
0 is set. Two boost pressure switches with this structure are used, one of which operates at -100 mmHg and the other at -380 mmHg, and both boost pressure switches operate on the circuit shown in Figure 9. and its output Pou _TL ,
By connecting Pou _TH to the reset terminals of the counters 504a and 504b of the time limit circuit 504 of the negative pressure detection section 500, control similar to that of the above embodiment can be obtained. At this time, the intake negative pressure is guided to the air chamber 905 by a rubber pipe through a pipe 901 with an adjusting screw. At this time, the differential pressure between the negative pressure and the atmospheric pressure pushes the diaphragm 907 to the right, but since it is pushed to the left by the spring 906, the contacts A and B are closed when the negative pressure is low. When the negative pressure increases, the force pushing the diaphragm 907 to the right overcomes the spring 906 and the contacts open.
The force of the spring 906 can be adjusted with the adjusting screw pipe 901, so this
-100mmHg if combined with 100mHg and -380mmHg
When above, the output Pou _TL of the circuit shown in Figure 9 is at “0” level, and when it is below -380mmHg, the output Pou _TH
becomes the “0” level. In the above embodiment, the vehicle is controlled as a whole, but for example, the slope detector 6
By providing indicators such as light emitting diodes, liquid crystals, lamps, etc. to the outputs of the zero acceleration detection section 400, slope determination section 700, etc., it can also be used as a travel information meter. Further, in the above embodiment, both the automatic transmission control system and the overdrive control system are controlled by an electric circuit including the transmission control circuit 70, but in order to cancel overdrive in a mechanically controlled automatic transmission, The ON/OFF control of the solenoid may be performed by the slope detector 60, the overdrive switch 50, and the overdrive release circuit 80. For information on opportunity-controlled automatic transmissions, please refer to the magazine ``Automotive Technology.''
It is publicly known in Vol. 32, No. 7, 1978, etc. As described above, according to the present invention, even when a brake signal is not detected, uphill and downhill slopes can be determined based on vehicle acceleration and intake pipe negative pressure. The effect is that overdrive can be canceled without requiring any special operation, and drivability on downhill and uphill slopes can be improved. Furthermore, in the present invention, when a brake operation is performed during downhill slope determination, it is possible to know the driver's intention to immediately release the overdrive release from the signal from the brake detection unit, and the brake signal is detected. Since the system detects a downhill slope in a shorter time than the downhill slope detection method that does not detect downhill slopes and releases overdrive, engine braking is applied to the vehicle, reducing the speed and giving the driver a sense of security. be. Also, since overdrive is released sooner, the burden of brake operation can be reduced more quickly, increasing safety.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall general configuration of the present invention, FIG. 2 is a block diagram showing the general configuration of the gradient detector in FIG. 1, and FIG. 3 is a reference clock section and timing diagram in FIG. Fig. 4 is an electrical wiring diagram showing the signal generating section, Fig. 4 is an electrical wiring diagram showing the vehicle speed detecting part and acceleration detecting part in Fig. 2, and Fig. 5 is an electrical wiring diagram showing the negative pressure detecting part and brake detecting part in Fig. 2. Figure 6 is an electrical wiring diagram showing the gradient determination section in Figure 2, Figure 7 is an electrical wiring diagram showing the overdrive release circuit part in Figure 1,
FIG. 8 is a sectional configuration diagram showing a boost pressure switch according to another embodiment of the present invention, and FIG. 9 is an electrical wiring diagram showing a negative pressure determination circuit section according to another embodiment of the present invention. 10...Rotational speed detector, 20...Throttle switch, 30...Shift position switch, 40
... Solenoid valve unit, 41 ... Solenoid for overdrive, 50 ... Overdrive switch, 60 ... Gradient detector with negative pressure detection and acceleration detection, 70 ... Speed change control circuit, 80 ... Overdrive release circuit, 400... Acceleration detection section, 500... Negative pressure detection section, 700... Gradient determination section.

Claims (1)

[Scope of Claims] 1. In an overdrive control device equipped with a transmission that detects the traveling speed of a vehicle and its engine load and automatically shifts to an overdrive state based on both detections, the acceleration of the vehicle is detected. a negative pressure detection unit that detects intake negative pressure of the engine of the vehicle; a brake detection unit that generates a brake signal when a brake operation of the vehicle is performed; the acceleration detection unit and the negative pressure detection unit , and each detection signal from the brake detection section, when the acceleration is below a predetermined value and the intake negative pressure is below a predetermined value continues for a predetermined period of time, a judgment signal is generated to judge an uphill slope. outputting a determination signal for determining a downhill slope when the acceleration is equal to or higher than a predetermined value and the intake negative pressure is equal to or higher than a predetermined value for a predetermined period of time; , slope determining means for outputting a determination signal for determining a downhill slope before the predetermined time elapses when the brake signal is detected; and a canceling means for canceling the overdrive based on each determination signal of the slope determining means. An overdrive control device comprising: