JP2863845B2 - Speed control device for vehicles with automatic transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a speed control device for a vehicle having an automatic transmission, and more particularly to a device for preventing sudden acceleration during creep running.

2. Description of the Related Art At present, as is well known in vehicles equipped with an automatic transmission, the output of an engine is transmitted to a specific movable member of a planetary gear train via a torque converter and further via a forward clutch or a reverse clutch. Input and output from other specific movable members of the planetary gear train are transmitted to drive wheels via a propeller shaft, a differential gear and a drive shaft so as to move the vehicle forward or backward.

A hydraulic control circuit is provided to determine a gear ratio in a gear train including movable members such as a planetary gear, a ring gear, and a carrier. (Fixed at II speed, but initially at I speed),
By selecting the speed selection lever position such as D (1st to 3rd speed automatic transmission), N (neutral), P (parking), the hydraulic circuit is switched.

When N (neutral) or P (parking) is selected from the several speed selection ranges, the line pressure generated in the hydraulic circuit fixes the forward clutch, the reverse clutch, and a certain specific movable member. The movable members such as gears are in a free state, and the torque is not transmitted to the output shaft side of the automatic transmission regardless of how much the engine rotates.

However, if the driver selects the speed-selecting lever position in one of the driving ranges such as LIII.D or R, the line pressure is applied to the forward clutch (reverse clutch and low and reverse brake only in the case of R) of the automatic transmission. As a result, the clutch or brake is engaged, and as a result, the torque of the engine is slightly transmitted to a specific movable member of the planetary gear train via the torque converter, and further transmitted to another specific movable member via the planetary gear train. The torque is transmitted to the driving wheels via a propeller shaft, a differential gear, and a drive shaft, and on a substantially horizontal road surface, the vehicle moves forward at a slight speed even when the driver does not depress the accelerator pedal (in the case of R, Reverse). This phenomenon is generally called "creep running" and is well known in vehicles equipped with an automatic transmission.

(Problems to be Solved by the Invention) However, immediately after the start of creep running or during the creep running, for example, a failure of a fuel supply system such as a carburetor,
In an electronically controlled fuel injection system, the engine overspeeds due to an unexpected cause such as malfunction of an electronic circuit or generation of noise, and the vehicle rapidly accelerates (D or the like) even though the driver does not press the accelerator pedal. In the case of (1), rapid acceleration forward, and in the case of R, rapid acceleration backward), there is a possibility that such a situation is dangerous. In addition, with only the well-known logic that "when the accelerator pedal is not depressed, the braking device is activated when the vehicle speed exceeds the critical vehicle speed (rotation)",
When the accelerator pedal is depressed and the foot is released from the accelerator pedal for the purpose of gradual deceleration during high-speed (high-speed) driving, the braking device operates and sudden braking is applied against the driver's will. There was a problem of how to solve this.

(Means for Solving the Problems) The present invention has been made to solve the above problems.
Even if the vehicle speed or the engine rotation speed tries to accelerate rapidly for some reason during creep running, when the vehicle speed or the engine rotation speed exceeds a predetermined limit speed, the vehicle is automatically braked instantaneously, Thus, unexpected sudden acceleration of the vehicle is prevented.

That is, the present invention relates to a vehicle provided with an automatic transmission having a speed selection range such as LIII.DNRP, and has the following means for each invention.

(1) a vehicle speed / voltage conversion means for detecting a vehicle speed and generating a voltage that follows the vehicle speed, a throttle switch that is linked to an accelerator pedal or a throttle valve and closes when the accelerator pedal is released, and a throttle switch A high negative pressure detection switch that is connected in series and opens when the engine intake negative pressure becomes high negative pressure; and the vehicle speed / voltage conversion means when both the throttle switch and the high negative pressure detection switch are closed. A comparison circuit for comparing the generated voltage with a limit voltage corresponding to a predetermined limit vehicle speed and generating a signal voltage when the former is greater than the latter, and braking means for braking the vehicle by generating the signal voltage Means comprising:

(2) Engine speed / voltage conversion means for detecting the engine speed and generating a voltage following the engine speed, and a throttle switch which is linked to an accelerator pedal or a throttle valve and which closes when the accelerator pedal is released. A high negative pressure detection switch connected in series with the throttle switch and opened when the engine intake pipe negative pressure becomes high negative pressure; and a high negative pressure detection switch when both the throttle switch and the high negative pressure detection switch are closed. A comparison circuit for comparing a voltage generated from the engine speed / voltage conversion means with a limit voltage corresponding to a predetermined limit engine speed to generate a signal voltage when the former is larger than the latter; and Braking means for braking the vehicle by generating a voltage.

(Function) In the invention of claim 1 or 2, the vehicle speed or the vehicle speed range is selected during the creep running in which the vehicle speed range is selected to any of the running ranges such as LIII.D or R and the accelerator pedal is released. When the engine speed exceeds a predetermined limit vehicle speed or engine speed, the braking means is automatically operated to apply braking to the vehicle, and the speed selection range is set to LI.
II. If the accelerator pedal is depressed and the accelerator pedal is depressed and the accelerator pedal is depressed and the accelerator pedal is released while the vehicle is running at a vehicle speed or engine speed exceeding the limit engine speed or engine speed, a high negative pressure is applied. The braking means is not operated by opening the detection switch.

(Embodiment) FIGS. 1 to 5 show an embodiment in which the invention described in claim 1 is applied to a torque converter vehicle with electronic control fuel injection.
A description will be given based on the drawings.

FIG. 1 shows an example of a traveling pattern during creep traveling of a vehicle, in which the horizontal axis represents time, and the vertical axis represents vehicle speed or engine speed. For example, a driver starts an engine,
After selecting the speed range of the automatic transmission to be either LIII.D or R, when the brake of the vehicle is released, the vehicle can be creeped (forward or forward) on a substantially horizontal road surface without the driver depressing the accelerator pedal. Reverse).

There is no problem as long as this creep running speed maintains an appropriate vehicle speed, but if the engine speed becomes abnormally high for some reason, the vehicle speed will also increase rapidly,
As shown by the dashed line P in FIG. 1, it rises rapidly, and becomes an extremely dangerous state.

Therefore, in the present invention, the limit speed indicated by Vc in FIG.
When the vehicle exceeds Vc, that is, at point K, the vehicle is automatically braked to reduce the vehicle speed to Vc or less as shown by the solid line Q, and a sudden rise in the vehicle speed again as shown by the broken line P '. At the same time, the vehicle speed was reduced to Vc or less at point K 'as shown by the solid line Q' as before, and the same operation was repeated every time there was a rapid rise thereafter, thereby preventing unexpected rapid acceleration. It is going to go.

FIG. 2 is a conceptual diagram of a vehicle speed control system for performing the above function, wherein 1 is a constant voltage generating circuit that generates a limit voltage Ec that follows (including in direct proportion to) the predetermined limit speed Vc;
Reference numeral 2 compares a voltage E input through a vehicle speed / voltage conversion means 9 and a throttle switch 10 to be described later with the limit voltage Ec, and generates a signal voltage of E-Ec = ΔE only when E> Ec. comparator circuit, 3 Zohaba circuit, 4 denotes a switch circuit for outputting a switching signal E _B receives the increased width voltage E _a from Zohaba circuit 3.

6 is an injector with a built-in solenoid valve which is a normally closed by a spring therein, is connected to the fuel supply passage 6a, the electromagnetic electric signal E _S is built to be generated properly time the proper time from the controller not shown By being applied to the solenoid coil of the valve, fuel proportional to the application time is injected toward the combustion chamber of the engine 7. Although not shown, fuel sent from the fuel tank by the fuel pump passes through a fuel damper and a fuel filter, and is then guided to the injector 6 through a fuel supply path 6a. The fuel injected by the injector 6 mixes with air passing through an intake passage (not shown) to form an air-fuel mixture, which burns and explodes in the combustion chamber.

7 is an engine including a combustion chamber, a piston, a crankshaft, etc., 8
Is a vehicle with an automatic transmission in which torque generated by the engine 7 is transmitted via a converter 8a.

Reference numeral 9 denotes a vehicle speed / voltage conversion unit that detects the vehicle speed V and generates a voltage E that follows (including in direct proportion to) the vehicle speed V.
An example will be described with reference to FIG. 3. The output shaft of a pinion 19 meshing with a worm gear 18 fixed to a main shaft 17 rotating in a transmission case 16 and the rotation of a speedometer cable 21 of a speedometer 20 are described. A DC generator 70 is provided between the shaft. This DC generator 70
Generates a voltage E that follows the vehicle speed V. In addition,
As the vehicle speed / voltage conversion means, for example, a converter in which a converter that detects the rotation speed of the pinion shaft and converts the pulse and a converter that converts the pulse to the voltage may be used in series may be used.

Referring again to FIG. 2, reference numeral 10 denotes a throttle switch, which closes as shown only when the driver releases his / her accelerator pedal, that is, when the throttle valve is closed, and when the driver depresses the accelerator pedal, That is, when the throttle valve is opened, the switch is opened as shown by a broken line.

Reference numeral 29 denotes a braking means, which is obtained by improving a known control device with a brake booster (commonly called Hydromaster). The details of the braking means 29 will be described with reference to FIG. In FIG. 4 (a), 31 is a rotating shaft 32
The brake pedal 33 is rotatable around the axis of the master cylinder 33. The master cylinder 33 is a piston 34 fastened to a rod 35. When the driver depresses the brake pedal 31, the rod 35 and the piston 34 are pushed to the left in the drawing, so that the oil filled in the master cylinder 33 and the halloid trick cylinder 36 is not shown as shown by the arrow Q. Is pressurized toward each of the hole cylinders, and the brake is applied.

In the braking means 29, a power cylinder 37 is provided to further increase the braking force. The power cylinder 37 is partitioned into a negative pressure chamber 39 and an atmosphere / negative pressure switching chamber 40 by a power piston 38. Power piston 38
Is connected to a hydraulic piston via a rod 41. A spring 43 for returning the power piston 38 is contracted in the negative pressure chamber 39, and a negative pressure in the intake pipe or the intake manifold 44 is constantly introduced through a pipe 44a.

The rotating shaft portion 32 of the brake pedal 31 is provided with a fan-shaped rotating valve body 45 integrally therewith.
When the driver releases his / her foot from the air inlet 31, the air flowing from the first air inlet 46 is shut off by the rotary valve body 45, and when the driver depresses the brake pedal 31 more, the air inlet 49 is opened. The negative pressure inlet 49a is closed. Reference numeral 47 denotes a conduit for guiding the intake manifold negative pressure to the chamber 47a, and reference numeral 48 denotes a negative pressure in the chamber 47a or the atmosphere to the power cylinder 3.
7 is a conduit leading to the atmosphere / negative pressure switching chamber 40.

Further, in this embodiment, a three-way solenoid valve 52 is provided between the pipe 48 and the pipe 50 leading to the atmosphere / negative pressure switching chamber 40. As shown in detail in FIG. 4 (b), the three-way solenoid valve 52 connects a valve body 53, a spring 54 for pressing the valve body 53 downward in the figure, and a pipe line 51a from the second air intake 51. Valve seat 54a for blocking the air flowing in through the valve body 53
And a solenoid coil 54c for moving the valve body 53 upward in the figure against the force of the spring 54, and a solenoid coil 54c.
And a valve seat 54b for preventing the intake manifold negative pressure from the pipeline 48 by the valve body 53 when the power is supplied to the valve.

In FIG. 2, reference numeral 30 denotes a normally closed high negative pressure detection switch. An example of the high negative pressure detection switch 30 will be described with reference to FIG. This switch 30 is a switch piece that is rotatable about an axis 57 of a fixed contact 56 connected to a lead wire 55 extending from one terminal side of the throttle switch 10.
58, and a lead wire 59 drawn out from the shaft center portion 57 and connected to the comparison circuit 2. The switch piece 58 has one end (the left end in the figure) when the shaft 61 and the intermediate member 62 are urged upward in the figure by the repulsive force of the first spring 60.
Is pushed upward, thereby electrically connecting the lead wires 55 and 59. The shaft body 61 is fixed to a diaphragm 64 that flexes in the vertical direction in response to a pressure change in the intake pipe or the intake manifold 44. One end (the left end in the figure) of the switch piece 58 is connected to a first spring. It is urged downward by the repulsive force of the second spring 65 smaller than the repulsive force of 60.

When the driver releases his / her foot from the accelerator pedal for deceleration, for example, during normal running other than creep running, the high negative pressure detection switch 30 significantly increases the degree of negative pressure in the intake pipe or the intake manifold 44. When the diaphragm 64 is pulled toward the intake manifold 44 as shown by a two-dot chain line against the repulsive force of the first spring 60, the switch piece 58 is pressed by the urging force of the second spring 65. Rotates counterclockwise in the figure and the fixed contact 56
It will be in an open state by moving away from it.

In the present embodiment having the above-described configuration, when the driver starts the engine, selects the speed selection range to either LIII.D or R, and releases the brake of the vehicle, the driver releases the accelerator pedal. The vehicle travels creep (forward or backward) even if it is not stepped on. In this case, since the throttle switch 10 is closed, the voltage E corresponding to the vehicle speed V generated by the vehicle speed / voltage conversion means 9 is input to the comparison circuit 2, but when the creep running speed does not exceed the limit speed Vc. is not generated signal voltage ΔE from the comparator circuit 2, thus switching signal E _B to be inputted to the three-way electromagnetic valve 52 of the braking means 29 is not emitted, the vehicle will continue to creep running.

On the other hand, when the vehicle speed V rises rapidly for some reason and exceeds the limit vehicle speed Vc, the voltage E corresponding to the vehicle speed V exceeds the voltage Ec corresponding to the limit vehicle speed Vc.
ΔE composed signal from the comparator circuit 2 is generated, E _A becomes increased width voltage is input to the switch circuit 4 through the Zohaba circuit 3, the switching voltage E _B solenoid coil 54c of the three-way electromagnetic valve 52 of the braking means 29 ( (See FIG. 5 (b)). Then, as a result of the valve body 53 moving upward against the force of the spring 54, the atmosphere enters the atmosphere / negative pressure switching chamber 40 from the second atmosphere intake 51 through the pipes 51a and 50, and the power piston 38 And, the hydraulic piston 42 is pushed leftward in the figure against the repulsive force of the spring to instantaneously and automatically apply braking. At this time, since the valve element 53 is in close contact with the valve seat 54b, the air does not flow into the pipe 48. That is, even if the driver does not step on the brake pedal 31, the vehicle is instantaneously and automatically braked.

When the vehicle is braked in this manner, the vehicle speed falls below the limit vehicle speed Vc within a short time as shown by the curve Q in FIG. 1, and E <Ec, so that the signal voltage Δ
As a result, the valve element 53 of the three-way solenoid valve moves downward in the figure due to the repulsive force of the spring 54, and the atmosphere / negative pressure switching chamber 40 communicates with the intake manifold 44 to switch to the negative pressure. When the piston 38 moves rightward in the figure due to the repulsive force of the spring 43, the braking is released. When the vehicle speed V exceeds the limit vehicle speed Vc again as shown by the broken line P 'in FIG. 1 and the vehicle speed V exceeds the limit vehicle speed Vc, the same operation as described above is repeated each time. The rise is prevented beforehand.

Also, for example, when the driver selects the speed selection range to one of LIII.D and is performing normal driving other than creep driving, the driver usually depresses the accelerator pedal, so the throttle switch 10 is open, and even if the vehicle speed V exceeds the limit vehicle speed Vc, the braking means 29 shown in FIGS.
Does not work. On the other hand, when the driver releases his / her foot from the accelerator pedal for the purpose of deceleration during normal traveling, the condition that the accelerator switch is closed and the condition of V> Vc are satisfied, so that the braking means 29 operates. .

However, in this embodiment, the high negative pressure detection switch 30 is provided in series between the comparison circuit 2 and the throttle switch 10, and when the driver releases his / her foot from the accelerator pedal during normal driving, the throttle switch Even if 10 is closed, the high negative pressure detection switch 30 is opened due to high negative pressure in the intake pipe or the intake manifold generated at the time of deceleration. For this reason, even if the above two conditions are satisfied, the operation of the braking means 29 is avoided. As a result, when the driver releases his / her foot from the accelerator pedal during normal running, unexpected braking of the driver, which may cause danger particularly at high speed running, is prevented.

Next, an embodiment in which the invention of claim 2 is applied to a torque converter vehicle equipped with an electronic control fuel supply device will be mainly described as a sixth embodiment.
This will be described with reference to FIG. 7 and FIG.

FIG. 6 is a conceptual diagram of the engine speed control system. The difference from the conceptual diagram of the vehicle speed control system shown in FIG. 2 is that the engine speed is detected instead of detecting the vehicle speed. The difference is that the engine speed / voltage conversion means 9 'is used in place of the vehicle speed / voltage conversion means 9 in the figure, and the other configuration is the same as that of FIG.

FIG. 7 shows an example of the engine speed / voltage conversion means 9 '.
It is composed of an ignition coil 27 and an F / V converter 28. A frequency proportional to the engine rotation speed taken out from the primary electrode of the ignition coil 27 or taken out is converted into a voltage by the F / V converter 28. Then, the converted voltage E 'is output to the comparison circuit 2 via the throttle switch 10.

In the above configuration, the driver sets the speed range to LIII.D.
Or R, and the voltage E 'corresponding to the engine speed becomes the limit engine speed Vc (see FIG. 1) during creep running in which the driver releases his / her foot from the accelerator pedal.
When exceeding the voltage Ec 'corresponding to emits a signal voltage ΔE from the comparator circuit 2, Zohaba circuit 3, the solenoid coil 54c of the three-way electromagnetic valve 52 of the switching voltage E _B of the braking means 29 through the switching circuit 4 Apply and apply braking instantaneously and automatically. The other operations are the same as those shown in FIGS.
In the description of the embodiment already described with reference to the drawings, terms such as "vehicle speed" and "limit vehicle speed" are referred to as "engine speed" and "limit engine speed".
It can be understood simply by substituting the terms such as, and the detailed description is omitted.

Therefore, in this embodiment, the same effect as that shown in FIGS. 2 to 5 can be obtained.

In each of the embodiments described above, the present invention is mainly applied to the case of creep running in a vehicle with an automatic transmission.
For example, by setting the limit vehicle speed or the limit engine rotation speed in a vehicle with an automatic speed control device to a desired value,
It is possible to prevent unexpected sudden speed changes in all running except creep running. In addition, the present invention can be applied not only to a torque converter vehicle with an electronic control fuel supply device but also to a torque converter vehicle with a carburetor type fuel supply device.

(Effects of the Invention) As described above, according to the present invention, the vehicle is automatically braked instantaneously every time the vehicle speed or the engine speed exceeds a predetermined limit vehicle speed or the limit engine speed during creep. The vehicle speed or the engine rotation speed can be reduced below the limit vehicle speed or the limit engine rotation speed, so that there is a main effect that danger due to sudden acceleration during creep running can be prevented beforehand. .

In addition, during normal running other than creep running, braking is not applied as long as the accelerator pedal is depressed, and when the accelerator pedal is released for deceleration, the degree of negative pressure in the intake pipe or intake manifold increases significantly. Is used to prevent braking, so that there is no danger due to unexpected playing by the driver especially during high-speed running.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example of a running pattern during vehicle creep running, FIG. 2 is a conceptual diagram of a vehicle speed control system showing one embodiment of the invention of claim 1, and FIG. FIG. 4 (a) is an operation explanatory view showing an example of a braking means, FIG. 4 (b) is a cross-sectional view of a three-way solenoid valve, and FIG. 5 is an operation showing an example of a high negative pressure detection switch. FIG. 6 is a conceptual diagram of an engine rotation speed control system showing an embodiment of the second aspect of the present invention, and FIG. 7 is a circuit diagram showing an embodiment of an engine rotation speed / voltage conversion means. 1 ... constant voltage generation circuit, 2 ... comparison circuit, 3 ... amplification circuit, 4 ... switch circuit, 6 ... injector, 6a ...
Fuel supply passage, 7 ... engine, 8a ... torque converter,
8 ... vehicle, 9 ... vehicle speed / voltage conversion means, 9 '... engine speed / voltage conversion means, 10 ... throttle switch,
16 ... transmission case, 17 ... main shaft, 18 ... worm gear, 19 ... pinion, 20 ... speedometer, 21 ... speedometer cable, 27 ... ignition coil, 28 ... F / V converter, 29 ... Brake means, 30 ... High negative pressure detection switch, 31 ... Brake pedal, 32 ... Rotating shaft part, 33 ... Master cylinder, 34 ...
Piston, 35… Rod, 36… Hydraulic cylinder, 37… Power cylinder, 38… Power piston, 39
…… Negative pressure chamber, 40 …… Atmosphere / negative pressure switching chamber, 41 …… Rod,
42 …… Hydraulic piston, 43 …… Spring, 44
... intake manifold, 44a ... pipe, 45 ... rotary valve body, 46 ... first air intake, 47 ... pipe, 47a ...
… Room, 48 …… Pipe, 49 …… Atmospheric inlet, 50 …… Pipe, 51
... Second air intake 51a... Pipeline 52... Three-way solenoid valve 53... Valve element 54... Spring 54a.
... valve seat, 54c ... solenoid coil, 55 ... lead wire, 56 ... fixed contact, 57 ... shaft part, 58 ... switch piece, 59 ... lead wire, 60 ... first spring, 61 ……
Shaft, 62 ... Intermediate member, 64 ... Diaphragm, 65 ... Second spring, 70 ... DC generator.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-62-225744 (JP, A) JP-A-62-70637 (JP, A) JP-A-2-3542 (JP, A) JP-A 62-225744 51730 (JP, A) JP-A-62-251251 (JP, A) JP-A-1-147134 (JP, A) Jiko 60-35816 (JP, Y2) (58) Fields investigated (Int. Cl. ⁶ , DB name) B60K 31/00-31/18 F02D 29/00-29/06 B60T 7/12-7 / 22,8 / 32-8/96 B60K 41/00-41/28 F02D 41/00- 41/40

Claims (2)

(57) [Claims] 1. A vehicle provided with an automatic transmission having a speed selection range such as LIII.DNRP, a vehicle speed / voltage conversion means for detecting a vehicle speed and generating a voltage following the vehicle speed, an accelerator pedal or a throttle valve. A throttle switch that closes when the foot is released from the accelerator pedal in conjunction with the throttle switch; a high negative pressure detection switch that is connected in series with the throttle switch and opens when the negative pressure of the engine intake pipe becomes high negative pressure; When both the high negative pressure detection switch is closed and the voltage generated from the vehicle speed / voltage conversion means is compared with a limit voltage corresponding to a predetermined limit vehicle speed, and when the former is larger than the latter, A comparison circuit for generating a signal voltage; and a braking means for braking the vehicle by generating the signal voltage.
LIII. When the vehicle speed exceeds the limit vehicle speed during creep running with the foot selected from any of the driving ranges such as D or R and the accelerator pedal released, the braking means is automatically activated to brake the vehicle. On the other hand, when the speed selection range is selected to either LIII.D or R and the accelerator pedal is depressed and the foot is released from the accelerator pedal while driving at a vehicle speed exceeding the limit vehicle speed, the high negative pressure detection is performed. A speed control device for a vehicle with an automatic transmission, wherein the brake means is not operated by opening a switch. 2. A vehicle equipped with an automatic transmission having a speed selection range such as LIII.DNRP, an engine speed / voltage conversion means for detecting an engine speed and generating a voltage following the engine speed. A throttle switch that is linked to the accelerator pedal or throttle valve and closes when the foot is released from the accelerator pedal, and a high negative pressure detection that is connected in series with the throttle switch and opens when the engine intake pipe negative pressure becomes high negative pressure When the switch, the throttle switch and the high negative pressure detection switch are both closed, the voltage generated from the engine speed / voltage conversion means is compared with a limit voltage corresponding to a predetermined limit engine speed. A comparison circuit for generating a signal voltage when the former is greater than the latter, and braking means for braking the vehicle by generating the signal voltage. When the engine speed exceeds the limit engine speed during creep running when the vehicle speed range is selected to any of the driving ranges such as LIII.D or R and the accelerator pedal is released, the braking means is automatically activated. Actuate the vehicle and apply braking to the vehicle while selecting the speed selection range to either LIII.D or R, and depress the accelerator pedal while driving at an engine speed exceeding the limit engine speed. A speed control device for a vehicle with an automatic transmission, wherein when the foot is released from the pedal, the high negative pressure detection switch is opened so that the braking means is not operated.