KR0173812B1 - Driving force control device and control method of vehicle - Google Patents

Abstract

The present invention relates to a driving force control apparatus for a vehicle, and particularly, to solve the problem of suction of a high pressure pump at a low temperature.

Connection to the inlet port, PTC thermistor attached to transfer heat to the connector, temperature sensor for detecting the temperature of the connector, high pressure pump to perform the ABS / TCS function with one pump, in the master cylinder at normal braking Shut-off valve to shut off the flow path by the braking pressure that comes out, spring to open the connecting pipe when not braking, check valve to provide rapid pressure increase, solenoid valve to adjust the braking pressure to depressurize, maintain and increase pressure (30, 31, 34) 35), consisting of a master cylinder (2) for forming the braking pressure by the pedal, and a booster (1), consisting of a hydraulic circuit that performs the ABS / TCS integration function, even when the control device is operating at low temperatures Means for applying heat to the connecting conduit to reduce the viscosity of the oil so that the oil is smoothly sucked from the oil tank to the hydraulic pump, and a part cooperating with the heating means. Consists of the means included.

Description

Driving force control device and control method of vehicle

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving force control device (TCS) of a vehicle. In particular, the driving force control can be smoothly performed by improving the suction problem of the pump during the TCS function at low temperature.

In general, the TCS controls the driving force of the driving wheel to obtain the optimal driving force when the driver wheel slips due to the momentary excessive driving force such as rapid start or rapid acceleration. It is a device that improves the smooth starting stability and steering performance of the vehicle by reducing the friction with the road surface, and adopts a method of increasing the pressure of the brake fluid by using a pump to obtain the power required for such a control device.

The prior art using the above method is U.S. Patent No. 5,342,120, the operation pedal 80, the booster 21, the master cylinder 18, which is connected to the engine controller as shown in FIG. Pedal (19), oil tank (60), high pressure pump (41, 52), low pressure pump (58), low pressure holding relief valve (57), hydraulic circuit protection relief valve (67), high pressure shut-off valve ( 32, 33, low pressure shutoff valves 36, 37, low pressure tank 39, wheels 16, 17, 13, 14, wheel speed sensors 72, 73, 74, 75, low pressure Check valve 66 for preventing pressure action by the pump, Solenoid valve 56 for pressure shutoff to the oil tank, Shut-off solenoid valve 54 for preventing the operating pressure by the high pressure pump from being directed to the master cylinder side, braking during TCS operation A release check valve 63 for smoothing the pressure of the master cylinder when required, and a cone for controlling the actuator when a wheel slip occurs. The controller consists of a solenoid valve (32, 36, 33, 37) and a high pressure pump (41, 52) for reducing, maintaining, or reducing the braking pressure when the anti-lock brake system (ABS) is operated. It is.

In the operation of the prior art, when the driving wheel slips due to sudden start or acceleration of the vehicle, the controller 71 that receives the signal from the wheel sensor 72.73 determines that the wheel 16 has slipped. In order to control the driving force, the solenoid valve 54 connected to the master cylinder is shut off, and the low pressure pump 58 is driven to apply the braking pressure to each wheel 16, 17, 13, 14 at the pressure set in the relief valve 57. And part is sucked into the high pressure pump (41) through a pipe (65).

The brake fluid of a constant pressure discharged by the low pressure pump 58 is prevented from going to the low pressure side by the check valve 66 to prevent the pressure drop, and is affected when the braking pressure is adjusted by the solenoid valves 36 and 37. Do not let them.

The brake fluid sucked into the inlet of the high pressure pump 55 through the check valve 50 becomes a high pressure by the action of the pump and controls the driving force of the drive wheels 16 and 17 through the solenoid valves 32 and 33.

This is a combination of solenoid valves (32, 36, 33, 37) to increase, maintain and decrease the braking pressure. In general, the high pressure pump (55) is continuously driven, and when it is increased, the solenoid valve is closed to increase the braking pressure. In case of reduction, the solenoid valves 36 and 37 are opened and brake fluid is sent to the low pressure side. At this time, the solenoid valve 56 is opened and the brake fluid flows to the oil tank to circulate.

When the wheel is locked, ABS is activated. In contrast to the TCS function, the braking pressure is reduced so that the braking force can be used in the range where the maximum friction coefficient can be obtained between the wheel and the ground plane. Keep it.

The above-described technique disclosed in U.S. Patent No. 5,342,120 is composed of a low pressure pump 58 and a high pressure pump 41. The low pressure pump 58 controls the sliding of the driven wheel and brake fluid to the intake port of the high pressure pump 41. Back pressure forming action to enter smoothly.

Actually, the pressure controlled by the driven wheel is insufficient to control only low pressure, so the main purpose of the pressure is the latter case, that is, when the ABS (Anti-skid Brake System) is operated, a little stored in the low pressure tanks 39 and 49 The back pressure of the brake fluid may be sucked into the high pressure pumps 41 and 52, but the TCS function which is operated without pressing the brake pedal has no brake fluid stored in the low pressure tank 39, so that the fluid flows from the oil tank 60 to the pipeline. There is a problem that the pressure must be generated by directly inhaling the brake fluid through (65).

At room temperature, the viscosity of the brake fluid is low so that it can be sucked into the high pressure pump 41 directly through the pipe line 65 without the low pressure pump 58, but at low temperatures (usually -20 ° C or less), the viscosity of the brake fluid increases. Due to the flow resistance is increased, the brake fluid is not sucked well by the high pressure pump 41 can not obtain the braking pressure for smooth braking.

Although a low pressure pump 58 is provided as a means to solve this problem, the configuration of such a hydraulic circuit requires the addition of a separate low pressure pump 58 and a solenoid valve 56. As a result, the hydraulic circuit becomes complicated, which leads to installation, price, and economical efficiency. It is disadvantageous in terms of phosphorus. In addition, the low pressure pump 58 is also difficult to fundamentally solve the pumping action by increasing the viscosity at low temperatures, there is a problem to control a smooth driving force with a fast response speed.

In addition, the driving force control apparatus of the vehicle according to the prior art has a problem that when the brake fluid is low temperature, the suction fluid is not smoothly sucked into the pump due to the increase in the viscosity of the brake fluid. CHARGE method is applied, but it is disadvantageous in terms of price, installation and miniaturization.

SUMMARY OF THE INVENTION An object of the present invention is to provide a driving force control device that solves the above-mentioned problems, and to provide a driving force control device that can improve the suction performance by making the configuration simple and maintaining the optimum viscosity even at low temperatures. .

1 is a hydraulic circuit diagram schematically showing the configuration of the prior art.

2 is a hydraulic circuit diagram according to the present invention.

3 is a detailed view of portion A of FIG.

4 is a detailed view of portion B of FIG.

5 is a control circuit diagram for explaining the operation of the present invention.

6 is another embodiment of the present invention.

7 is a schematic diagram of a PTC thermistor.

8 is a characteristic diagram of temperature resistance of a PTC thermistor.

* Explanation of symbols for main parts of the drawings

1: booster 2: master cylinder

3: oil tank 10: driving force control device

20: Master cylinder shutoff solenoid valve

22: relief valve 23: check valve

24: temperature sensor 25: heating wire

26: connecting pipe 27: coating for preventing heat dissipation

28: return spring 29: shutoff valve

30,34: high pressure shutoff solenoid valve 31,35: low pressure shutoff solenoid valve

36,37: Pressure release check valve 40,42: Wheel sensor

43: driven wheel 44: driving wheel

45: low pressure tank 46: high pressure pump

47: buffer chamber 61: the battery

62: switch 74: controller

90: lead wire 91: space part

92: PTC thermistor 93: electrically conductive adhesive layer

94: heat sink (terminal) 95: ceramic coating layer

96: far-infrared radiation layer 97: insulation and fixing member

The control apparatus 10 according to the present invention does not require a low pressure pump as shown in FIGS. 2 to 5, but is connected to an inlet of the high pressure pump 46 directly from the oil tank 3 ( 26, a PTC thermistor 92 having a heating wire 25 to transfer heat to the connection pipe 26 to suppress the increase in viscosity of the brake fluid at a low temperature, and a temperature sensor 24 for sensing the temperature of the connection pipe 26. ), A battery 61 for supplying power to the PTC thermistor, a switch 62 for opening and closing the battery, a controller 74 for controlling the switch 62 according to the signal of the temperature sensor 24, and one pump. High pressure pump 46 to perform the ABS / TCS function, a shut-off valve 29 to block the flow path using the braking pressure from the master cylinder during normal braking, a spring 28 to open the connection pipe 26 when not braking, And because of the instability of the body during TCS function, the driver needs to brake arbitrarily. When it is made of a configuration consisting of a check valve 23 for providing a rapid pressure increase.

The wheel sensors 40 and 42 detect the speed of the wheels 43 and 44 in the ABS function, and the solenoid valves 30, 31, 34 and 35 to adjust the braking pressure to the pressure reducing, maintaining and increasing pressure state. And a master cylinder (2) and a booster (1) for forming a braking pressure.

The PTC thermistor 92 is coated with a heat dissipation preventing coating 27 to prevent damage to the peripheral device as shown in FIG. The device having the PTC thermistor 92 has a lead thermistor 90 inside thereof to form a PTC thermistor which is a heating element. It is firmly attached by the electrically conductive adhesive layer 93 to form the electrical conductivity. In addition, a ceramic coating layer 95 coated with SiO ₂ or ZrO ₂ ceramics is formed.

In order to prevent oxidation of the metal terminal (heat sink) and to protect the PTC thermistor, the far-infrared radiation layer 96 is formed by spraying aluminosilicate or cordierite on the ceramic coating layer 95.

The terminal (heat radiating plate) is firmly attached to the groove formed in the upper insulation and the fixing member 97, and forms a space portion 91 to block the heat conduction in the upward direction.

The lead wire 90 is welded to the terminal (heat sink) to connect a power source, and an electrically insulating coating is formed to electrically insulate from the outside.

Referring to the operation of the present invention having such a configuration as follows.

In response to a signal from the temperature sensor 24 at the start of the engine, the controller 74 turns on the switch 62 of the battery 61 and intercepts when the temperature of the brake fluid reaches the set value.

When a current is applied to the PTC thermistor 92 through the lead wires and the terminals by the power supply, the heat is transferred to the outside by the ceramic coating layer and the radiation layer having excellent thermal conductivity, and the heating target is heated and the viscosity of the brake fluid It is kept low to prevent the loss of pumping function due to the deterioration of suction performance, which enables smooth braking pressure rise regardless of the ambient temperature.

When the suction amount is necessary for braking, the brake fluid is filled in the low pressure tank 45 by the decompression action, and the brake fluid is circulated to smoothly and continuously control the driving force.

Systemic operation of the solenoid valve 20 is determined by the controller 74 determines the slip of the wheels (43, 44) signals from the wheel sensors (40, 42) when the slip of the driving wheel occurs due to the rapid start, acceleration, etc. of the vehicle ) Blocks the master cylinder 2 side and drives the high pressure pump 46 to supply the braking pressure to the drive wheel 44 below the pressure set in the relief valve 22. At this time, the brake fluid is sucked from the oil tank 3 to the suction port of the high pressure pump 46 through the connecting pipe 26.

The pressure boosted by the high pressure pump 46 has a structure in which the pulsation is reduced through the buffer chamber 47 and the orifice 51 in order to reduce the pressure pulsation, and the working pressure is applied to the driving wheel through the connected conduit. .

When the wheel locks up, the ABS is activated. In this case, the braking force is kept low by reducing the braking pressure as opposed to the TCS function, which controls the solenoid valves 30, 31, 34, and 35 to control the solenoid valves 30, 31, 34 and 35. Do it.

If braking is required due to instability of the vehicle during operation of the TCS, the braking pressure may quickly reach the wheel through the check valve 23.

The driving force control device of the present invention does not require a separate low pressure pump 58 and a shut-off solenoid valve 56 as in the prior art, and the desired driving force can be obtained with a simple circuit configuration, thereby simplifying the pipeline, thereby reducing the cost and weight. It is advantageous from the side.

In addition, the optimum oil viscosity can be maintained according to the set temperature of the thermistor, and can be selectively installed in the required portion.

According to the embodiment of the present invention shown in FIG. It is designed to shorten the length of the pipeline and to reduce the resistance of the suction tube. By installing a small PTC thermistor in such a space and heating it, it has the effect of fundamentally solving the suction problem by keeping it below an appropriate viscosity.

In addition, a small space can be provided in the shutoff valve as shown in FIG. 4 to obtain the same effect as above.

In still another embodiment of the present invention, as shown in FIG. 6, a small space connected to the pump suction conduit is installed in a block in a hydraulic device located on a flow path to be sucked by a high pressure pump directly from the master cylinder. In order to reduce the resistance of the pipeline, it is possible to adopt a structure that solves the problem of inhalation by installing a small thermistor and heating it so that it always keeps below the proper viscosity.

As described above, the present invention has been described in detail through the above embodiments, but it is intended that modifications and variations can be made without departing from the scope of the appended claims by those skilled in the art.

Claims (4)

Connection to the suction port, PTC thermistor attached to transfer heat to the connector, a temperature sensor for detecting the temperature of the connector, high-pressure pub to perform the ABS / TBC function with one pump, in the master cylinder at normal braking Shut-off valve to shut off the flow path by the braking pressure that comes out, spring to open the connecting pipe when not braking, check valve to provide rapid pressure increase, solenoid valve to adjust the braking pressure to depressurize, maintain and increase pressure (30, 31, 34) 35), consisting of a master cylinder (2) for forming the braking pressure by the pedal, and a hydraulic pressure circuit for performing the ABS / TBC integration function, consisting of a buster (1), low temperature when the control device is operated Means for applying heat to the connecting pipe to reduce the viscosity of the oil so that the oil is smoothly sucked from the oil tank to the hydraulic pump, A driving force control apparatus for a vehicle comprising a speed means. According to claim 1, a means for reducing the resistance of the pipeline by placing a small space in the hydraulic system between the oil tank and the pump inlet to reduce the resistance of the pipeline, and installed in the block of the pipeline or hydraulic system to reduce the viscosity of the brake fluid And a PTC thermistor for heating the brake fluid, and means for wrapping the heat in the thermistor so that the heat of the thermistor is concentrated in the conduit or the block of the hydraulic system. The flow path of claim 2, wherein a small thermistor is installed in order to maintain the viscosity of the oil flowing into the suction pipe at an appropriate level at all times, and to be directly sucked by the high pressure pump from the master cylinder to reduce the resistance to the suction pipe. A driving force control device for a vehicle, characterized in that a small space is connected to the pump suction line in the block in the hydraulic system located in. In the driving force control device of a vehicle, a brake is formed by a PTC thermistor heating device mounted therein to form a space in the shutoff valve so that the viscosity of the brake fluid sucked by the high pressure pump maintains the optimum viscosity even at low temperatures and the suction performance is improved. Driving force control device for a vehicle, characterized in that configured to increase the viscosity of the liquid.