JP2649048B2 - Control method of hydraulic transmission for diesel vehicle - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for controlling a hydraulic transmission of a high horsepower high speed diesel vehicle.

(Prior Art) Diesel vehicles are provided with a torque converter between the engine and the transmission in order to improve acceleration during starting. In recent years, the shape of this torque converter has been
A three-stage six-element torque converter that can obtain a large stall torque is preferably used. Even if the engine horsepower is small, a large output torque is generated at the time of starting, so that the starting can be easily performed. As shown in FIG. 5, the three-stage six-element torque converter T comprises one set of impellers I, three sets of turbines T ₁ , T ₂ , T ₃ and two sets of stators S ₁ , S ₂ . . The power from the diesel engine E rotates through the transmission clutch V to rotate the impeller I of the torque converter T to rotate the turbines T ₁ , T ₂ , and T ₃ by the circulating flow given to the fluid in the circuit.

Stators S ₁ and S ₂ for changing the direction of the fluid flow are provided between the turbines T ₁ , T ₂ and T ₃ . The output from the turbine T _1, T _2, T ₃ of the torque converter T is provided to the transmission T _m through a freewheeling FW. Such a torque converter can obtain a large stall torque, so it has good acceleration at the start of the vehicle. However, if a large horsepower engine is installed for high speed, the output torque at the start is too large, Exceeding the adhesive force causes the wheels to spin and accelerates the friction of the wheels and rails. To avoid this, it has been necessary to use a torque converter with a small stall torque or to artificially limit the engine horsepower.

(Problems to be Solved by the Invention) Since the weight of a diesel locomotive is lighter than that of a diesel locomotive, if the output torque at the time of starting is increased for the purpose of improving acceleration, the output torque exceeds the adhesive force of the wheels. As a result, idling occurs. In addition, once idling occurs, the friction coefficient between the wheel and the rail changes from the static friction coefficient to the kinetic friction coefficient, so that the adhesive force of the wheel is extremely reduced and it is difficult to converge. For this reason, if the vehicle slips at the time of starting, the vehicle stops and the vehicle continues to idle at the same position, so that the wheels are worn and the rails are also worn. As a result, there is a problem that a situation in which the rails need to be replaced is lost, and a great deal of cost and labor is spent. SUMMARY OF THE INVENTION It is an object of the present invention to solve such a problem and to provide a method of controlling a fluid transmission for a diesel vehicle that prevents occurrence of idling at the time of starting.

(Means for Solving the Problem) The present invention increases the horsepower of the engine in order to achieve high acceleration and high speed of a diesel vehicle, and increases the reduction ratio of the first gear by setting the transmission to the second gear. The output torque obtained at low output rotation speed at the start is increased, and the engine rotation speed is adjusted to the output rotation speed so that this output torque is maintained at an allowable torque that does not exceed the adhesive force of the wheels. Let control. When starting, the control of the engine speed to maintain the output torque at the allowable torque is performed by detecting the engine speed signal and
The detected signal of the rotation speed of the output shaft is compared with the signal converted to the corresponding engine rotation speed that does not cause the wheels to spin at the rotation speed, and the signal obtained by the calculation and adjustment is used as a signal of the engine in the form of hydraulic pressure through a proportional solenoid valve. This is achieved by operating an actuator linked to the throttle lever.

(Operation) FIG. 3 shows a comparison between the present invention and the conventional example, in which the horizontal axis represents the rotation speed of the output shaft of the transmission (hereinafter referred to as the output rotation speed).
Is plotted on the ordinate, where the torque of the output shaft of the transmission (hereinafter referred to as output torque) and the engine speed are plotted, and the relationship between the two is plotted. In FIG. 3, the solid line indicates the present invention, and the dashed line indicates the conventional example. The output torque during the shift operation via the torque converter with the engine at full notch is represented by the line segments a and b, respectively. Is shown. Line segment c indicates the allowable output torque for preventing the wheels from spinning. Conventionally, in the range of low output rotation speed at the time of starting, the output torque b during shifting exceeds the allowable torque c. In order to avoid this, a torque converter with a small stall torque ratio was used, and the engine rotation was kept low by artificially limiting the notch. On the other hand, in the present invention, the output torque is controlled by continuously controlling the engine speed so as to maintain the output torque at the allowable torque c. The engine speed at the time of applying the normal output torque a is indicated by d, and the required engine speed for reducing the output torque a to the allowable torque c is indicated by a solid line e. That is, if the engine rotational speed, the output rotational speed O~n to correspond to the output rotational speed ₁ range controlled as e, as the output torque of the solid line c, the maximum allowable output torque c greater than b Means to be maintained. When the output rotational speed exceeds n _1, the output torque a becomes lower than the allowable torque c, fear of slipping is eliminated. The rotational speed d becomes the engine is obtained under Furunotchi operation, the output torque is reduced as a in (range rotational speed is n ₁ ~n _2). By entering direct one-speed operation and switched from shifting clutch lockup clutch in the output rotational speed n ₂ Then, the output torque becomes as f. When the output rotational speed reaches the n ₃ further increases, the first speed clutch
It switched from F ₁ to 2 speed clutch F ₂ (Figure 5), the output torque with increasing output rotational speed changes as g. On the other hand, the rotational speed of the engine fluctuates in a saw-tooth manner like h and i. Also, j indicates the output torque at the time of the direct connection operation of the conventional example, which is the same as g of the present invention because it has the same reduction ratio. If it is attempted to increase the speed stage to two speeds without controlling the engine rotation in the conventional example, when starting at the first speed, the output torque is too large and the vehicle idles, so that there is a disadvantage that a large gear ratio cannot be selected. Next, FIG. 4 shows another characteristic of the equation of the present invention, in which a large-sized torque converter and a small-sized torque converter are selected to be applied to an engine of the same horsepower, and the performances are compared. is there. The performance of a large size torque converter (hereinafter referred to as converter L) is indicated by a dotted line, and the performance of a small size torque converter (hereinafter referred to as converter S) is indicated by a solid line. In order for converter S to absorb the same horsepower as converter L, the engine and matching speed of converter S must naturally be higher than that of converter L. However, an increase in the engine speed in the low speed range has a problem of noise at the time of departure, and is not preferable. However, since the method of the present invention can suppress the engine speed at the time of departure, this concern is eliminated. In other words, adopting this method eliminates the need to use a torque converter with a low torque ratio to prevent slippage, and eliminates the need to use a large-sized converter to keep the matching rotation speed low. And the performance-oriented selection can be performed.

Fourth at allowable output torque C ₁ in Figure, the output torque by the torque converter converter S is a _1, and the converter L is the same with a _2, the engine rotational speed adapted to the torque converter at d _1, d ₂ respectively and the engine rotational speed to maintain the output torque to the allowable output torque C ₁ is respectively shown in e _1, e _2. As for the range of speed operation exceeding the allowable output torque C _1, but a ₂ exceeds the a ₁ at low output shaft rotation speed, the torque converter so is limited to a low allowable output torque C ₁ Izure in this range The effect due to the size of the capacitor can be ignored.

In then speed operation range where the output shaft rotational speed is lower than to output torque allowable output torque C ₁ increases, a ₁ is a
_More than _two . As described above, the torque converter of the present system has a large output torque as compared with the conventional system despite its small capacity.

(Embodiment) FIG. 1 is a block diagram of a hydraulic transmission incorporating an example of a control device for performing the control of the present invention, FIG. 2 is an example of a veloc diagram of the control device, and FIG. FIG. 1 shows a simple configuration diagram of a hydraulic transmission to which the control method of the present invention is applied.

First, in FIG. 1, reference numeral 1 denotes a diesel engine, the output of which is transmitted from an output shaft 6 to a driving wheel (not shown) via an engine output shaft 2, a transmission clutch 3, a torque converter 4 and a transmission 5.

In Figure 5 that the control method is showing an example of a fluid type transmission of the present invention is applied, the rotation of the engine E is transmitted to the output shaft O through the shifting clutch V, and the torque converter T and a transmission T _m You. When the transmission clutch V is engaged, the speed-changed rotation through the torque converter T is selectively output through the freewheel Fw through the gears and the forward / reverse switching clutch RF, and then the transmission clutch V is released. When engaging the first speed clutch F ₁ Te, rotation of the direct first speed of the engine E, is configured to output similarly direct the second speed and with further engagement a second speed clutch F _2.

In FIG. 1, reference numeral 7 denotes a throttle lever 8 of the engine 1.
Actuator that operates the actuator, and a proportional solenoid valve
The pressure oil controlled at 10 is supplied through the oil passage 11 to operate, adjusts the fuel injection amount of the engine, and controls the output torque of the engine.

This means that a proportional solenoid valve 10 is provided with an engine speed detector 12 provided on the output shaft 2 of the engine 1 and a transmission 5.
The controller 16 compares the detection signals 14 and 15 from the output rotation speed detector 13 provided on the output shaft 6 with a signal 17 obtained by a comparison operation as described later.
Control is performed so as not to exceed the allowable output torque for preventing wheel idling. Further, the controller 16 receives the signal 18 ₁ of the number of notches from the notch control lever 18, compares it with the above signal, selects the minimum value, and outputs it to the proportional solenoid valve 10. When the proportional solenoid valve 10 receives the signal of the notch number, the throttle lever 8 is actuated through the actuator 7 so as to give a fuel injection amount corresponding to the signal.
Control.

FIG. 2 is a block diagram showing the configuration of the controller 16 described above, and its operation will be described with reference to FIG.
First, in a shift operation at the time of starting, the detection signal 14 from the engine speed detector 12 is converted into a voltage signal 20 by the F / V converter 19.
Then, a function converter 21 performs a function conversion into a signal of the output shaft rotation speed corresponding to the engine rotation speed based on the relationship indicated by the oblique line e in FIG. 3, and an output shaft rotation speed detector 13. The detection signal 15 from the F / V converter 23 and the voltage signal 24 converted by the F / V converter 23 are supplied to a comparison calculator 25 to obtain a deviation. The deviation signal 26 is converted into a signal 28 adjusted by a PID controller 27 to be described later. The minimum value selector 29 selects and outputs the signal 30 as an amplifier.
The amplified signal 17 is supplied to the solenoid 32 of the proportional solenoid valve 10 via the signal 31. The proportional solenoid valve 10 receives this signal 17 and controls the output shaft 6 to apply an allowable output torque as shown by a solid line C in FIG.

When the output shaft rotational speed reaches the n ₁ increases the engine in a state of full operation, as the engine rotational speed output torque a change as shown by the solid line d (solid line) falls below the allowable torque C (dotted line) Therefore, no idling occurs.
Even if the lever is in a full operation at an output rotation speed of n ₁ or less, the signal 22 giving the engine output rotation speed e is the minimum value of the full notch signal giving a higher rotation speed. Since it is selected and output by the selector 23, occurrence of idling can be prevented beforehand. Thus, by the lever to the state of Furunotchi, the output shaft rotational speed exceeds n _1, the minimum value selector 25 is likewise full operation is supplied to the proportional solenoid valve to select the Furunotchi signals from the lever State.

Under such full operation, the output shaft rotational speed reaches the n ₂ continues to rise, the detection signal of the rotational speed at this time shifting clutch (V of FIG. 5) - direct clutch (FIG. 5 F ₁ ) The automatic switching device is operated, and the switching control from the shift operation to the direct connection first speed operation is performed by a known method.

By controlling the acceleration in the variable speed operation as described above, the occurrence of idling of the wheels is prevented. Also, due to changes in the natural environment or the like, the adhesive force of the rail may be reduced to a value lower than the expected value, and idling may occur even if the output torque is maintained at the allowable torque C. An automatic control circuit for avoiding this is also included. (See FIG. 2).

Wheel slip is detected from a sudden change in rotation of the output shaft 6, which outputs a pulse signal 15 from an output shaft rotation speed detector 13 to a slip detector 33 to count pulses.
The slip is detected at the degree of the increase in the count number, and the slip signal 34 is output. This signal 34 is amplified by an amplifier 35 to excite a relay 39 for operating an A contact switch 37 and a manual return contact switch 38.

Operating as described above, when the A-contact switch 37 is closed, the one-notch signal 41 from the one-notch setting unit 40 is converted into a signal 42 via the switch 37, and the B-contact switch 43 of the manual reset contact switch 38 is opened. Then, the signal 22 from the function converter 21 is cut off, and the A-contact switch 44 is closed to switch to the signal 46 from the function converter 45 and output as a signal 47. The signal 24 and the comparator 25 are compared. , Through a PID controller 27 and given to a minimum value selector 29 as a signal 28.

At this time, the minimum value selector 29 selects the one-notch signal 42 having a low value, supplies it to the proportional solenoid valve as the signal 17 via the amplifier 31, and controls the engine to output one notch.
When the output of the engine is reduced to one notch at a stroke in this way, the output torque of the transmission is rapidly reduced and the idling is stopped.

When the slip detection signal 36 is cut off when the idling is stopped in this way, the relay 39 is demagnetized, the A contact switch 37 is opened and the one notch signal is cut off, but the switch 44 of the manual reset contact is closed. Since the state is maintained, the minimum value selector switches the signal 28 from the function converter 45 to a one-notch signal and outputs it. The output from the function converter 45 is controlled so as to give an engine speed lower than the solid line e indicating the output of the function converter 21, as shown by the two-dot chain line e 'in FIG. Accordingly, the output torque is also reduced as indicated by the two-dot chain line a ', and no idling occurs.

Also, since the role of the one-notch setting device is to stop the idling by lowering the rotation speed of the engine, the set value is not limited to one notch and the minimum value may be reduced to the limit where engine stall does not occur. Also, the maximum may be increased to the limit where idling stops.

(Effect of the Invention) In a hydraulic transmission of a diesel vehicle, the output torque at the time of starting is reduced to an allowable output torque that does not cause idling of the wheels, and the engine rotation speed is adjusted so that the allowable output torque is maintained. Controlled so as not to exceed the permissible output torque in accordance with the shaft rotation speed, preventing idling at the time of starting and eliminating wear on wheels and rails, and the cost and labor required for their replacement and maintenance. Can be greatly reduced, and the maximum output torque can be obtained over the entire speed change range, so that there is an effect that the acceleration performance is also improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of a hydraulic transmission for a diesel vehicle and an example of a control circuit diagram of the present invention. FIG. 2 is an example of a block diagram of an electronic control circuit of the present invention. Is a comparison diagram plotting the relationship between the rotation speed of the output shaft and the engine rotation speed or output torque for the present invention and the conventional example.
FIG. 5 shows a simple structural diagram of a fluid transmission to which the control method of the present invention is applied. E …… Diesel engine, T …… Torque converter T _m …… Transmission

Claims (1)

(57) [Claims] A drive system for a diesel vehicle that transmits power from a diesel engine to wheels via a hydraulic transmission including a clutch, a torque converter, and a transmission. A torque converter that allows transmission of large output torque and large horsepower at the output rotation speed is provided,
By controlling the engine rotation speed using the rotation speed detection signal of the transmission output shaft to reduce the output torque at the time of starting to the allowable output torque that does not cause the wheels to spin and maintain the allowable output torque, A method of controlling a hydraulic transmission for a diesel vehicle, wherein a maximum output horsepower is obtained by preventing the occurrence of idling of wheels at the start of a shift operation.