JPH0613262B2 - Neutral control device for gearshift steering device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] According to the present invention, when a driver puts a change lever in a neutral position, the transmission is surely put in a neutral state, and the driver inadvertently moves a steering wheel or an accelerator. The present invention also relates to a neutral control device for a gear shift steering device that prevents a vehicle from moving.

[Conventional technology]

Conventionally, a gearshift steering device that has a continuously variable transmission mechanism that is driven by an engine and that has a plurality of speed stages and a hydraulic pump motor that is continuously variable at each speed stage The discharge rate of the variable speed hydraulic pump is not normally controlled.

[Problems to be solved by the invention]

For this reason, although it is desirable to stop the vehicle immediately after changing the position from the neutral state to the forward movement, the reverse movement, or the super-fine turning, it is not possible to appropriately control the discharge amount of the shifting hydraulic pump. In some cases, the output shaft of the gearshift steering device rotates and the vehicle suddenly starts moving.
It is a defect.

In addition, even if the discharge rate of the variable-speed hydraulic pump is controlled in advance in the neutral state, the discharge rate control signal will remain at a constant value due to individual differences in hydraulic pump motor products, changes in efficiency with aging, and effects of load. It is difficult to output an appropriate ejection amount control signal because there is no guarantee that the above will be maintained.

The present invention has been made to eliminate the above-mentioned conventional drawbacks. Even if the driver inadvertently moves the steering wheel or accelerator, the vehicle does not move, and the driver changes the change lever to a position other than the neutral position. Even immediately after
The vehicle will not move abruptly, it will be possible to prepare in advance for sure stopping, and it will be possible to avoid the efficiency changes due to individual differences of the hydraulic pump motor for shifting and aging, the influence of load, etc. An object of the present invention is to provide a neutral control device for a speed change steering device.

[Means for solving problems]

A neutral control device for a gear shift steering device according to the present invention has a gear shift section having an gear shift hydraulic pump driven by an engine and a gear shift hydraulic motor driven by the oil discharged from the gear shift hydraulic pump, and an output shaft. A gear shift steering device including a steering unit that selects the speed change unit to a plurality of speed stages, a first means that outputs a control signal for releasing all clutches when the position of the position selection switch is neutral, and a position Second means for outputting a latch control signal only when the selection switch is in the neutral position and the output speed of the transmission unit is smaller than the comparison signal corresponding to the reference vehicle speed, and the speed ratio is always zero when the vehicle is stopped. The shift pump discharge rate control actuator that controls the oil discharge rate of the shift hydraulic pump in this way, and the shift pump discharge rate when the position of the position selection switch is not at the neutral position. A stop control circuit that outputs a control signal for controlling the control actuator, and a stop control circuit that outputs the discharge amount control signal immediately before the latch control signal is input and that does not input the latch control signal A latch circuit for holding the control signal output from
When the position selection switch is in the neutral position, the control signal of the latch circuit is selected, and when the position is not neutral, the control signal of the stop control circuit is selected and input to the shift pump discharge amount control actuator. is there.

[Action]

According to the invention, when the position selection switch is in the neutral position, the first means outputs a control signal for releasing all the clutches, and at the time of outputting this control signal, the speed changer output rotation speed is output from the comparison signal corresponding to the reference vehicle speed. The latch control signal is output by the second means only when the value is small, and the control signal is output from the stop control circuit when the position of the position selection switch is not in the neutral position. This control signal causes the shift pump discharge amount when the vehicle is stopped. The control actuator controls the oil discharge amount of the speed change hydraulic pump so that the gear ratio is always zero, and while the latch control signal is being input to the latch circuit, the discharge amount control immediately before it is input is controlled. It outputs a signal and holds the control signal output from the vehicle stop control circuit while the latch control signal is not input to the latch circuit. Tsu position of switch selects the control signal of the latch circuit when the neutral position of the position selection switch selects the control signal of the stop control circuit when a non-neutral,
The selected control signal acts to supply the shift pump discharge amount control actuator.

〔Example〕

An embodiment of a neutral control device for a gear shift steering device according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the embodiment. In FIG. 1,
The gearshift steering device 1 has one input shaft 9 connected to the engine 4.
And having two (left and right) output shafts 10 and 11,
The transmission unit 2 and the steering unit 3 are included.

The speed change unit 2 is provided with a speed change hydraulic pump 5 driven by the engine 4 and a speed change hydraulic motor 6 driven by the oil discharged from the speed change hydraulic pump 5.

The output shaft of the speed changing hydraulic motor 6 is connected to the planetary gear train of the speed changing unit 2 so that the mechanically transmitted power from the engine 4 and the power from the speed changing hydraulic motor 6 are combined. ing.

Further, the speed change unit 2 has a plurality of planetary gear trains and a plurality of hydraulically operated clutches, and by selectively engaging one of the hydraulically operated clutches, the speed change unit 2 is switched between the first speed to the fourth speed. You can select the speed stage.

Further, there are two sets of bevel gears and two hydraulically operated clutches for switching between forward and reverse. Here, the shifting hydraulic pump 5 is a variable displacement pump, and the rotation speed of the shifting hydraulic motor 6 can be controlled by controlling the discharge amount thereof.

By controlling the number of revolutions of the shifting hydraulic motor 6, the shifting unit 2 is capable of continuously shifting at each speed stage.

On the other hand, the steering unit 3 includes a steering hydraulic pump 7 driven by the engine 4 and a steering hydraulic motor 8 driven by the oil discharged from the steering hydraulic pump 7. The output shaft of the steering hydraulic motor 8 is connected to the planetary gears on the left and right output shafts of the gearshift steering device so as to be reversed in the left-right direction, and is combined with the power of the gearshift output shaft.

The steering hydraulic pump 7 is a variable displacement pump, and the rotation speed of the steering hydraulic motor 8 can be controlled by controlling the discharge amount thereof. When the number of rotations of the steering hydraulic motor 8 is zero, the number of rotations of the left and right output shafts becomes the same number of revolutions, the vehicle travels straight, and when the rotation of the steering hydraulic motor 8 is forward or reverse, The rotation speed of the left and right output shafts varies depending on the rotation speed, and the vehicle can turn right or left.

The discharge rate of the shift hydraulic pump 5 is controlled by the shift pump discharge rate control actuator 12, and the control signal k from the control device 31 is input to the shift pump discharge rate control actuator 12. It is supposed to be done. Therefore, with this control signal k,
The shift pump discharge rate control actuator 12 controls the discharge rate.

Similarly, the control device 31 sends a control signal 1 to the steering pump discharge amount control actuator 13. The steering pump discharge rate control actuator 13 controls the discharge rate of the steering hydraulic pump 7 by this control signal 1.

Further, a control signal m is sent from the control device 31 to the fuel injection amount control actuator 14. With this control signal m, the fuel injection control actuator 14 controls the fuel injection amount to the engine 4.

Based on the rotation speed of the engine 4, the engine rotation speed detector 21 detects the engine rotation speed signal N _E , and the control device 31
It is designed to be sent to.

Further, the shifting hydraulic motor rotational speed detector 22, is taken out hydraulic motor speed signal N _M for shifting by the rotation speed of the shifting hydraulic motor 6, so as to deliver to the controller 31.

In the speed change unit 2, the speed change unit output speed detector 23 takes out the speed change unit output speed signal N _O based on the speed change unit output speed and sends it to the control device 31.

On the other hand, the steering unit 3, the hydraulic motor speed detector 24 for steering, remove the hydraulic motor speed signal N _N for steering by the hydraulic motor speed for steering, to deliver to the controller 31 Has become.

Signals a to c are input to the control device 31. The signal a is output from the accelerator pedal position detector 25, and is obtained by the accelerator pedal position that controls the rotation speed of the engine 4.

Further, the position selection switch 26 detects four types of positions of the change lever, ie, forward, reverse, neutral, and super turning, and signals corresponding to each of the four types of positions are obtained.

The brake pedal position detector 27 detects the position of the brake pedal and takes out the signal c.

Further, the steering wheel detector 28 detects the steering wheel turning angle for turning the vehicle and sends the signal d to the control device 31.

Control signals e, f, g, and h from the control device 31 are the first speed clutch actuating solenoid valve 15, the second speed clutch actuating solenoid valve 16, the third speed clutch actuating solenoid valve 17, and the fourth speed clutch actuating, respectively. The electromagnetic valves 18 are sent to the respective electromagnetic valves 18.

These control signals e to g are respectively used to engage the hydraulically actuated clutch for selecting each speed stage of the transmission unit 2.

Further, a control signal i is sent from the control device 31 to the forward clutch actuating solenoid valve 19, and
The control signal j is sent to the reverse clutch actuating solenoid valve 20. The control signals i and j are control signals for engaging the hydraulically operated clutch for switching between forward and reverse.

As is apparent from the above, the control device 31 outputs the signals a ...
d, the engine speed signal N _E , the speed change hydraulic motor speed signal N _M , the steering hydraulic motor speed signal N _N , and the speed change section output speed signal N _O are input. The control signals k and l are output to the speed changing hydraulic pump 5 and the steering hydraulic pump 7, respectively.
A control signal m is sent to the fuel injection amount control actuator 14 of the engine 4.

Further, in response to the input signal, as described above from the control device 31, the control signals e to h are sent to the solenoid valve 15 for operating the first speed clutch or the solenoid valve 18 for operating the fourth speed clutch, and the control signal i. Alternatively, j is sent to the forward clutch actuating solenoid valve 19 or the reverse clutch actuating solenoid valve 20.

Next, the operation of the neutral control device for a gear shift steering device of the present invention configured as described above will be described. The shift steering device 1 according to the present invention has forward and reverse switching clutches at its input portion, and the engine output is not transmitted to the shift steering device in a state where these clutches are not actuated. 1 is in a neutral state (neutral).

In this neutral state, the shifting hydraulic pump 5 does not rotate and does not discharge or suck in oil, so the shifting hydraulic motor 6 does not rotate. However, when the forward clutch, the reverse clutch and the first speed clutch are actuated from the neutral state, the respective parts in the gear shift steering device 1 start to rotate.

At this time, the shift pump discharge amount control actuator 12
Is not properly controlled, the rotation of the speed change hydraulic motor 6 does not reach a value that makes the speed change section output shaft rotation zero.
The vehicle may start moving.

It is desirable that the vehicle be stopped immediately after the driver switches the change lever from the neutral position to the forward position, the reverse position, or the super-fine turning position.

The speed change portion of the speed change steering device according to the present invention comprises a hydrostatic-mechanical continuously variable transmission mechanism, By changing from positive maximum to negative maximum, Can be continuously changed. This hydraulic speed ratio y
FIG. 2 shows the relationship between the speed ratio x and the forward speed ratio and the reverse speed ratio.

In FIG. 2, it is assumed that the hydraulic speed ratio y at which the speed ratio x is zero (the vehicle stops) is y (0). The control signal k of the shift pump discharge amount control actuator 12 corresponding to y (0) is k (0). Even when neutral, if the control signal k = k (0) is given to the speed change pump discharge amount control actuator,
The vehicle can be kept in a stopped state regardless of whether the driver switches the change lever to move forward, reverse, or turn to the super-fine ground.

However, k (0) does not always have a constant value due to individual differences in the shifting hydraulic pump 5 and the shifting hydraulic motor 6 for each product, a change in efficiency due to aging, or an influence of load.

Therefore, if the control signal k that sets the speed ratio x to 0 is constantly monitored, and this value is replaced with the latest value and is output during the neutral control, the above-mentioned individual differences and the like can be practically neglected. it can.

FIG. 3 is a block diagram showing a detailed configuration of the control device 31 in FIG. In FIG. 3, the same parts as those in FIG. 1 are designated by the same reference numerals.

In FIG. 3, the signal b (position signal) from the position selection switch 26 is the neutral judgment logic circuit 32,
The data is input to the logic circuit 34 and the vehicle stop control circuit 36.

In the neutral judgment logic circuit 32, when the signal b is b = b _N (neutral position signal), the control signals e to j for turning off all the clutch actuating solenoid valves and releasing each clutch are provided. First speed clutch actuating solenoid valve 15 to fourth speed clutch actuating solenoid valve 18, forward clutch actuating solenoid valve 1
9. Output to the reverse clutch actuating solenoid valve 20.

On the other hand, the rotational speed signal N _O shifting portion output from the transmission unit output speed detector 23, at the output speed comparator 33 is adapted to be compared and the comparison signal N _OC corresponding to a reference vehicle speed If, as a result of this comparison, the transmission output speed signal N _O is smaller than the comparison signal N _OC , the output rotation decrease signal P is output.

The output rotation reduction signal P is input to the logic circuit 34.
The logic circuit 34 outputs the control signal q and sends it to the latch circuit 35 only when the output rotation lowering signal P is input and the signal b = b _N.

At the same time, the control signal k for controlling the shift pump discharge amount control actuator 12 is input to the latch circuit 35.

On the other hand, from the vehicle stop control circuit 36, when the vehicle is stopped (forward, backward, or supercritical turning, the speed ratio x = 0).
In the case of 1), the control signal k of the shift pump discharge amount control actuator 12 controlled so that the speed ratio x is always zero is output.

The vehicle stop control circuit 36 operates when the signal b ≠ b _N and outputs the control signal k to the changeover switch 37.
This changeover switch 37 is a neutral judgment logic circuit 32, and b =
When the switching signal r output when the condition of b _N is satisfied is input, it is switched to the output side of the latch circuit 35, and when the switching signal r is not input, it is switched to the output side of the vehicle stop control circuit 36. .

The changeover switch 37 is provided in the shift pump discharge amount control actuator 12 in the latch circuit 35 or the vehicle stop control circuit 36.
It has a function of selecting and sending the two kinds of control signals k from.

In the latch circuit 35, while the control signal q is not input,
The latest value of the control signal k from the vehicle stop control circuit 36 is always held (stored), and while the control signal q is being input, the value of the control signal k immediately before the control signal q is being input is output. It is like this.

In this way, the control signal k output from the latch circuit 35 can be regarded as the value when the vehicle is stopped when the comparison signal N _OC is sufficiently small. Therefore, the control signal k output from the latch circuit 35 becomes the signal k (0) that makes the speed ratio x zero.

As described above, when the control signal k of the shift pump discharge amount control actuator 12 has a value that makes the speed ratio x zero when the gearshift steering device is in the neutral position, the driver replaces the change lever to move to a position other than the neutral position. Even if the position is selected, the vehicle can surely stop immediately after that. Therefore, the present invention can be applied to a gearshift steering device for a tracked vehicle, and can be widely applied for the purpose of improving neutral characteristics of a hydrostatic-mechanical continuously variable transmission of the same type.

〔The invention's effect〕

As described above, according to the neutral control device for a gear shift steering device of the present invention, when the vehicle is stopped and the change lever is in the neutral state, power is transmitted to the steering system depending on the structure of the gear shift steering device. The vehicle turns when the steering wheel or the clutch is moved by means of the steering wheel. However, in the present invention, it is possible to avoid a situation where the driver moves the vehicle even if the driver accidentally moves the steering wheel or the accelerator.

Also, since the speed change pump discharge rate control actuator is operated and made to stand by at a position where the speed ratio should be zero, the vehicle may move unexpectedly even immediately after the driver replaces the change lever with a position other than the neutral position. This is no longer the case, and it is possible to prepare in advance for sure stopping.

Furthermore, the control signal that makes the speed ratio zero is constantly monitored,
Since this value is replaced with the latest value and is output at the time of neutral control, it is possible to avoid the influence of the load, etc. due to the individual difference of the hydraulic pump motor for speed change, the aging change, and the like.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a neutral control device for a gear shift steering device of the present invention, and FIG. 2 is a diagram showing the relationship between the hydraulic speed ratio and the speed ratio in the neutral control device for a gear shift steering device. FIG. 3 is a block diagram showing a detailed configuration of a control device in the neutral control device for a gear shift steering device of the same as FIG. DESCRIPTION OF SYMBOLS 1 ... Gearshift steering device, 2 ... Gearshift part, 3 ... Steering part, 4 ... Engine, 5 ... Gearshift hydraulic pump, 6 ... Gearshift hydraulic motor,
7 ... Steering hydraulic pump, 8 ... Steering hydraulic motor, 12 ...
Speed change pump discharge rate control actuator 13 ... Steering pump discharge rate control actuator 21 ... Engine speed detector 22 ... Speed change hydraulic motor speed detector 23
.. Gearbox output speed detector, 24 ... Steering hydraulic motor speed detector, 25 ... Accelerator pedal position detector, 26 ...
Position selection switch, 27 ... Brake pedal position detector, 31 ... Control device, 32 ... Neutral judgment logic circuit, 33
... output speed comparator, 34 ... logic circuit, 35 ... latch circuit, 36 ... stop control circuit, 37 ... changeover switch.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takehisa Shio 3,000 Tana, Sagamihara City, Kanagawa Mitsubishi Heavy Industries, Ltd. Sagamihara Works

Claims (1)

[Claims] 1. A shift unit having a shift hydraulic pump driven by an engine and a shift hydraulic motor driven by the discharge oil of the shift hydraulic pump, and an output shaft, wherein the shift unit has a plurality of speed stages. When the position selection switch is in the neutral position, the gear shift steering device including the steering unit to be selected in the above, first means for outputting a control signal for releasing all the clutches, and the position selection switch in the neutral position And second means for outputting the latch control signal only when the speed changer output speed is smaller than the comparison signal corresponding to the reference vehicle speed, and the speed change hydraulic pressure so that the speed ratio is always zero when the vehicle is stopped. The shift pump discharge rate control actuator for controlling the hydraulic discharge rate of the pump, and the shift pump discharge rate control actuator when the position selection switch is set to a position other than neutral. A stop control circuit for outputting a control signal for controlling the user, and a discharge control signal immediately before being input while the latch control signal is being input and the stop control circuit being not input with the latch control signal. A latch circuit for holding a control signal output from the control circuit and a control signal for the latch circuit are selected when the position of the position selection switch is in the neutral position, and a control signal for the stop control circuit is selected when the position is not in the neutral position. A neutral control device for a gear shift steering device, comprising: a changeover switch that is input to the above-mentioned shift pump discharge amount control actuator.