JPS60146748A - Stop controlling method for vehicle with hydraulic mechanical transmission-steering device - Google Patents

Abstract

PURPOSE:To enable reliable stop of a vehicle, by a method wherein a hydraulic pump is controlled so that the number of revolutions of a hydraulic motor is regulated to about zero, and the vehicle is braked through operation of a brake. CONSTITUTION:When a change lever neutral single from a detector 13 is inputted to a theoretical circuit 28, the circuit 28 computes a means speed V from a signal for the number of revolutions of an engine from a detector 15, signals for the number of revolutions of motors on both sides from detectors 16 and 17, and a speed stage signal from one of hydraulic switches 18-21, and the speed V is compared with a set car speed Vc. Since neutral control is effected in the case of V<Vc, the circuit 28 determines all signals to change-over switches 22-25 into zero to disconnect each of clutches G-J. Simultaneously, signals (i) and (j) to discharge control actuators 26 and 27 of hydraulic pumps 6 and 7 on both sides, to which a stop signal, determining so that signals for the number of revolutions of motors on both sides are adjusted to about zero, are transmitted. Thus, the number of revolutions of each of the motors 8 and 9 is adjusted to about zero, and simultaneously, brake signals (p) and (q) are outputted to solenoids 29 and 30 to actuate a brake.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises: a mechanical transmission that transmits the power of an engine to left and right output shafts; a hydraulic pump driven by the engine; This article relates to a stop control method for stopping a vehicle (mainly a tracked vehicle) equipped with a hydromechanical transmission/steering device consisting of a hydraulic motor connected to a transmission. In the direction machine.

A hydraulic pump and motor are used, and the hydraulic motor's rotational speed is detected, and the hydraulic pump and discharge volume are adjusted to 1i to bring it closer to zero! control for neutral control.

However, if an attempt is made to stop the vehicle using the conventional neutral control, the problem arises that due to deterioration of the hydraulic pump and motor or insufficient adjustment, the neutral control control is not performed properly and the vehicle cannot be stopped.

In conventional neutral control, the hydraulic motor rotation speed nmk
The hydraulic motor rotation speed is controlled by detecting it, processing it in a logic circuit, and outputting a hydraulic pump discharge volume control current t that brings the hydraulic motor rotation speed close to zero. Two sets of left and right hydraulic pumps and motors are used, and these two left and right hydraulic pump discharge volume control currents i1. The relationship between i and the rotation speeds nm of the two left and right hydraulic motors is shown in Figures 1 and 2.

The result is as shown in FIG.

For example, the rotation speed of two left and right hydraulic motors is “IsW!112”.
As shown in Figure 1, Prefecture 2, and Stripe 3, there is a region in which the motor rotational speed does not change with respect to the control current '1+'2. This area will be referred to as a dead band from now on.

In Fig. i'1 □, Fig. 2, and Fig. 3, -, is the rotation speed of the left hydraulic motor, n is the rotation speed of the right hydraulic motor, il is the left hydraulic pump discharge volume control current, and i is the right hydraulic pump discharge volume. The solid line shows the relationship between the left hydraulic pump discharge volume control current i1 and the left hydraulic motor rotation speed h□,
The dotted line indicates the relationship between the right hydraulic pump discharge volume control current number and the right hydraulic motor rotation speed n1.

As shown in Figure 1, both dead bands W8.6 (tl=
O+ nm, = O) + ('!= O+ ntq
= O), the vehicle can be stopped using conventional neutral control. However, the hydraulic pump
If one or both of the dead bands f, , F, deviates from the origin due to motor deterioration or insufficient adjustment, as shown in Figure 2, 12 will gradually shift from the state of *t = Q r when the engine starts due to neutral control. Changed to.

In response, the motor rotation changes from point 7 to point B.

In other words, the vehicle moves during that time.Also, as shown in FIG. 3, there is a dead band W1. If one or both of tI'4 deviates from the origin, ! During p-stand control, LH and tt always try to converge to 0 points, but since the target is 0 points and 1 point and does not have a width of 91, n
continues to tremble slightly around the 0 point. In other words, the town vehicle will move slightly and will not be able to stop completely ◇ In this way, the rotation speed l of the conventional VC hydraulic motor is detected.

With the neutral control method of controlling the hydraulic pump rotation speed so as to bring it close to zero, it is virtually impossible to stop the vehicle reliably.

The present invention was developed in view of the above circumstances, and its purpose is to control a hydraulic pump so that the rotation speed of the hydraulic motor approaches zero.

The present invention provides a stop control method for a vehicle equipped with a hydraulic transmission/steering device that enables the vehicle to be reliably stopped by activating the brake and braking the vehicle.

The present invention will be described in detail below with reference to FIG. 4 and subsequent figures.

Ichibushi Alf ('H left six pairs of misocha≠gyo-gyo setbacks 14-R are provided, and the vehicle body l is equipped with an engine 2, a hydromechanical transmission/steering device C and an accelerator D, which will be described later).

Handle E% chain lever F etc. are provided.

Fig. 5 is an explanatory diagram of the hydromechanical transmission/steering machine.
In the figure, 1 is a mechanical transmission device 6 that has an input shaft 3 and two (left and right) output shafts 4 and 5 connected to the engine '2.
, 7 are hydraulic motors driven by the discharge oil of two (left and right) hydraulic pumps B and 9Fi hydraulic pumps 6 and 7 driven by the engine 2, and output shafts of these motors 8 and 9. is connected to the transmission, and by controlling the discharge volume of the hydraulic pump 6.7, the transmission 1 can be shifted steplessly within each speed stage. Transmission &lK includes clutch G for 1st speed, clutch H for 2nd speed, clutch I for 3rd speed,
There is a 4-speed clutch J, and by selectively operating each of them with hydraulic pressure, the rotation speed of the output shaft 4.5 is changed from 1st to 4th speed, and the left and right output shafts are 4.
5 is the sprocket of the left and right track type traveling devices B and H)
731, 〇11 connected to 8/ is the accelerator D
A throttle position detector 12 detects the throttle position operated by the engine 2 to control the rotation speed of the engine 2 and outputs a signal α thereof, and 12 is a handle E for turning the vehicle.
13 is a handle angle detector that detects the turning angle of the change lever F and outputs a signal, and 13 detects the four positions of the change lever F: forward, reverse, neutral, and super turning, and sends a signal corresponding to each position. 14 is an engine brake switch that outputs signal d for applying the engine brake; 15 is the actual engine speed (W);
16.17 is a motor rotation speed detector that outputs the engine rotation speed signal "ml'" mz of each hydraulic motor 8, 90; 18.19. 20゜21 detects the hydraulic pressure of the clutches G and J for 1st to 4th speeds and outputs the respective signals ' and f.
r! Hydraulic switch to take out I + A, 22, 23
, 24 and 25 are clutch changeover switches for controlling the first to fourth speed clutches G-/, and 26 and 27 are actuators for controlling the discharge volume of both pongs 6 and 7. 2g
is a control logic circuit, and this circuit 28 receives each of the above signals α~
By inputting h and "' Wm+, flM,
In response to the input signal, a signal L1 is output to the discharge volume control actuator 26.27 of both pumps 6.7, and signals l, m, and n are output to each clutch changeover switch 22 to 25. .

29 and 30 are left and right output shaft brake actuation actuators, and the control logic circuit 28 sends a signal P to the brake actuation actuators 29 and 30 in accordance with the change lever position signal C.
, q are output, and the brakes 31 and 32 are turned on and off.

A specific example of neutral control in the above device will be described with reference to FIG.

When the change lever is in the neutral position, or when it is switched from another position (running state) to the neutral position, a neutral signal C is input from the change lever position detector 13 to the logic circuit 28. At this time, the engine speed detector I
5, the rotation speed signal n from the left and right motor rotation speed detectors 16°, the rotation speed signal -1, N from the left and right motor rotation speed detectors 16°, and the oil pressure switch for one speed stage among the oil pressure switches 18 to 21 for each speed stage. The vehicle speed calculation device 50 calculates the average speed V of the vehicle at the current speed stage from the speed stage signals - to h, and outputs the vehicle speed signal V. Neutral signal C and vehicle speed signal ν
is input to the comparison circuit 51, it is determined whether the vehicle speed V is greater or less than a preset vehicle speed Vc.

Here, if V>Vc, neutral control is not performed, but control is performed to reduce the vehicle speed, and if V>Vc, neutral control is performed.

When it is determined that neutral control is to be performed, all signals h-n from the logic circuit 28 to each of the clutch changeover switches 22 to 25 become zero, and each clutch G to J is disengaged. At the same time, stop signals I and I6 are calculated from the left and right motor rotational speed signals n and n. The rotational speed signal nn approaches zero.''S*%'' The stop signal 1., I, is sent separately to the signals i, no to the discharge/specific volume control actuators 26, 27 of the left and right hydraulic pumps 8, 9, respectively. They are added via adders 81 and 82.

As a result, the rotation speed of each motor 8, 9, that is, the rotation speed of the left and right output shafts 4, 50 approaches zero, and at the same time, the brake ON signal P + q is applied to the left and right brake operating solenoid 29.
．． 30 and activates the brake. If the above-mentioned neutral control is performed, the speed will be lower than a certain set speed Vc.

The vehicle can be stopped reliably.

As described above, the present invention can reliably stop a vehicle.

[Brief explanation of the drawing]

Figure 1 and Figure 2% Figure 3 is a table showing the relationship between the hydraulic pump discharge volume control current and the hydraulic motor rotation speed, Figure 4 and subsequent figures show embodiments of the present invention, and Figure 4 shows the FIG. 5 is an explanatory diagram of the hydromechanical transmission/steering device, and FIG. 6 is a stop control circuit diagram. 1 is a transmission, 2 is an engine, 3 is an input shaft, 4.5 is an output shaft, 6 and 7 are hydraulic pumps, and 8 and 9 are hydraulic motors. Agent Patent Attorney Masaaki Yonehara Figure 4

Claims (1)

[Claims] One input shaft 3 and left and right output shafts 4 connected to the engine 2
, 5 and a multi-stage transmission hydraulic pressure 2 inch G-/, left and right hydraulic pumps 6 and 7 driven by an engine 2, and driven by the oil discharged from these pumps. The output shafts of the left and right hydraulic motors 8, 9 are connected to the transmission 1, and the transmission port is connected to each speed stage by controlling the discharge volume of the hydraulic pump 6.7. Equipped with a hydromechanical transmission/steering device that allows for stepless speed changes.
In a vehicle in which the left and right traveling devices @B and B are connected to the left and right output shafts 4.5, the vehicle speed P is constant due to the neutral signal C from the change lever accompanying detector 13 indicating that the change lever is in the neutral position. When the speed drops below the speed limit, disengage all clutches G-/, activate the brakes to brake the vehicle, and also turn on the neutral signal and the motor rotation speed of each of the left and right hydraulic motors 8.9. Each rotational speed signal n, , nm, from .17 and two stop signals 1. ,
I6 is output, and this stop signal Ill, I is sent to the discharge volume control actuators 26 to 26 of the left and right hydraulic pumps 6 and 7 separately.
27, equipped with a hydromechanical transmission/steering device characterized in that the output is made such that the rotational speed of the hydraulic motors 8-9 driven by the respective hydraulic pumps 6 and 7 approaches zero. Vehicle stop control method.