JPH08193657A - Drive control device of vehicle - Google Patents

Abstract

PURPOSE: To realize the HST control without impeding the ABS operation by operating two-pressure control valve when the ABS is operated to control to further reduce the hydraulic pressure of the low hydraulic pressure line. CONSTITUTION: In the forward traveling, the high pressure oil is applied to a hydraulic motor 2 from a hydraulic pump 1 through a high hydraulic pressure line 4, and the oil from this hydraulic motor 2 is returned to the hydraulic pump 1. Hereupon, a two-pressure control valve 7 is connected to the low hydraulic pressure line 5, and its set pressure is controlled by a solenoid 8 to be driven by the output of an ABS operation detecting means 6. When a brake pedal is stepped in, detection is made whether or not the ABS is operated, and in the condition Where the ABS is not operated, the two-pressure control valve 7 is controlled through the solenoid 8 to limit the pressure in the low hydraulic pressure line 5 to the intermediate pressure of 240kg/cm<2> and keep only the braking function of the HST. In the condition where the ABS is operated, the low hydraulic pressure line 5 is kept at the low pressure <=150kg/cm<2> .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle drive controller, and more particularly to a vehicle drive controller using a hydrostatic continuously variable transmission to which ABS control is applied.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional hydrostatic continuously variable transmission (HS).
T) shows a hydraulic control circuit in a drive control device of a vehicle used, where 1 is a hydraulic pump driven by an engine, and 2 is a hydraulic pump.
Is a hydraulic motor, and 3 is a propeller shaft driven by the hydraulic motor 2.

In such a conventional vehicle, when moving forward, high-pressure oil of, for example, 400 kg / cm ^{2 is applied} from the hydraulic pump 1 to the hydraulic motor 2 via the high hydraulic line 4, and the oil from the hydraulic motor 2 is added. The hydraulic pump 1 is returned to the hydraulic pump 1 through the low hydraulic pressure line 5. When braking with a brake, the swash plate (not shown) of the hydraulic pump 1 is returned to the neutral position to release the driving force.

However, in such a case, the hydraulic pressure in the low hydraulic pressure line 5 is 400 k as in the high hydraulic pressure line 4.
It becomes g / cm ² or so, a large braking force acts on the hydraulic motor 2, for thereby locking the wheels can not exerting an anti-lock braking system (ABS), the hydraulic pressure of the low pressure line 5, for example 240 kg / c
It is restricted so that it does not exceed m ² so that ABS can act.

[0005]

However, even in the vehicle in which the hydraulic pressure of the low hydraulic pressure line 5 is limited as described above,
It is not possible to operate the BS sufficiently, and the acceleration at the time of reverse travel becomes poor. On the other hand, if the hydraulic pressure in the low hydraulic pressure line 5 is suppressed to, for example, 150 kg / cm ² , the braking force by the HST during forward movement will decrease.

The present invention eliminates the above drawbacks.

[0007]

A drive control system for a vehicle according to the present invention comprises a two-pressure control valve connected to a low hydraulic pressure line of a hydraulic control circuit of a hydrostatic continuously variable transmission, and means for detecting the operation of an ABS. , A control means for operating the two-pressure control valve during ABS operation so as to further lower the hydraulic pressure of the low hydraulic pressure line.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

In the present invention, as shown in FIG.
A means 6 for detecting the operation of S is provided, and a two-pressure control valve 7 is provided for a low hydraulic pressure line 5 of a hydraulic control circuit of a vehicle using HST.
To control the two-pressure control valve 7 via a solenoid 8 driven by the output of the operation detecting means 6 of the ABS. During the operation of the ABS, the hydraulic pressure of the low hydraulic line 5 is, for example, 150 kg / cm. ^The pressure is limited to ² or less, and the low hydraulic pressure line 5 is limited to 240 kg / cm ² or less when the ABS is not operated.

Since the vehicle drive control device of the present invention has the above-mentioned structure, it is detected whether or not the ABS is operated when the brake pedal is depressed, as shown in FIG.
When S does not operate, the low pressure line 5 is controlled to 240 k
If the HST alone is used, the low hydraulic pressure line 5 will be maintained at a low pressure of 150 kg / cm ² or less when the ABS is operating, and the low hydraulic pressure line 5 is limited to an intermediate pressure of g / cm ² or less. Instead, the ABS control becomes fully functional.

[0011]

As described above, according to the vehicle drive control device of the present invention, there is a great advantage that the HST control can be realized without inhibiting the ABS operation.

[Brief description of drawings]

FIG. 1 is a hydraulic control circuit diagram of a vehicle drive control device of the present invention.

FIG. 2 is an operation explanatory view of the vehicle drive control device of the present invention.

FIG. 3 is a hydraulic control circuit diagram of a conventional vehicle drive control device.

[Explanation of symbols]

 1 hydraulic pump 2 hydraulic motor 3 propeller shaft 4 high hydraulic line 5 low hydraulic line 6 operation detection means 7 2 pressure control valve 8 solenoid

Claims (1)

[Claims] 1. A two-pressure control valve connected to a low-hydraulic line of a hydraulic control circuit of a hydrostatic continuously variable transmission, a means for detecting the operation of ABS, and the two-pressure control valve operated during ABS operation to operate the two-pressure control valve. A drive control device for a vehicle, comprising: a control means for controlling the hydraulic pressure of the low hydraulic pressure line to be further lowered.