JPH0327900Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a power steering device for a vehicle such as an automobile, and more particularly to a torque steer prevention device for a power steering device.

In front-engine, front-drive vehicles equipped with an automatic transmission, when the vehicle is turning and you press the accelerator pedal to accelerate, the automatic transmission shifts down and transmits the signal from the engine to the drive system. A so-called torque steer phenomenon may occur in which the driving force suddenly increases and the steering wheel is directed in a direction that increases the turning radius of the vehicle.
This torque steer phenomenon also occurs in vehicles equipped with a power steering device that generates an assist force to drive the steering system in response to rotational operation of the steering wheel, thereby enabling easy operation of the steering wheel. .

The present invention increases the assist force of the power steering device when the transmission is downshifted with the steering wheel turned at a predetermined angle or more in a vehicle equipped with the power steering device, thereby preventing the torque steer phenomenon. An object of the present invention is to provide a torque steer prevention device for a power steering device that prevents torque steer from occurring.

This purpose, according to the present invention, includes first and second passages that are communicatively connected to each other at one end and have first and second variable throttles in their respective middles, and said first and second passages at one end, respectively. and third and fourth passages that are connected in communication with each other at the other end and have third and fourth variable throttles in the middle, respectively, and the first to fourth variable throttles are connected to the steering wheel. When the wheel is in a substantially neutral position, the first and fourth variable throttles reduce the throttle amount, and when the steering wheel is rotated in the left turn direction of the vehicle, the throttle volume increases, and the second and third variable throttle The variable throttle includes a control valve configured to increase the throttle amount when the steering wheel is rotated in a right-turning direction of the vehicle, a reservoir tank that stores working fluid, and the one ends of the first and second passages. a supply conduit that communicates with the reservoir tank and the other ends of the third and fourth passages; a return conduit that communicates with the reservoir tank and the other ends of the third and fourth passages; and the other ends of the first passage and the third a first conduit that communicates and connects the one end of the passageway with one cylinder chamber of the power cylinder; the other end of the second passageway, the one end of the fourth passageway and the other cylinder chamber of the power cylinder; a second conduit that communicates with the chamber and is provided in the middle of at least one of the first and fourth passages and at least one of the second and third passages, respectively, and is energized; first and second electromagnetic throttle valves that increase the speed of the vehicle; The valve is energized for a certain period of time, and when the steering wheel is rotated by a predetermined angle or more in a right-turning direction of the vehicle and the transmission is downshifted, the second electromagnetic throttle valve is energized for a certain period of time in response. This is achieved by a torque steer prevention device for a power steering device having a control device configured as described above.

According to this configuration, when the transmission is downshifted while the steering wheel is turned at a predetermined angle or more, the pressure of the working fluid supplied from the reservoir tank to the cylinder chamber via the control valve is increased. This increases the assist force of the power steering device and cancels the force that causes the torque steer phenomenon, so even if the transmission is downshifted while the steering wheel is turned at a predetermined angle or more, torque steer will not occur. It is possible to prevent the phenomenon from occurring.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings.

Fig. 1 is an illustration showing the main parts of one embodiment of the torque steer prevention device according to the present invention, which is incorporated in a power steering device in which the control valve is a flapper valve, and Fig. 2 shows the torque steer prevention device shown in Fig. 1. FIG. 3 is a circuit diagram of a control device for controlling an electromagnetic throttle valve of the prevention device. In these figures, 1 indicates a control valve. The control valve 1 consists of a directional control valve 2 and a pressure control valve 3. The valve bodies 4 and 5 of the directional control valve 2 and the pressure control valve 3 are connected to axes 8 and 9 by a steering wheel 7 via a steering gear box 6, respectively.
Becoming driven around. In FIG. 1, the valve bodies 4 and 5 are connected to the steering wheel 7.
is shown rotated in the left turn direction of the vehicle.

The control valve 1 includes a first passage 15, which is connected to each other at one end in the valve chamber 10 of the directional control valve 2, and has a first variable throttle 11, 12 and a second variable throttle 13, 14 in the middle, respectively. 16 and second passages 17, 18, one end of which is connected to the other end of the first passage 15, 16 and second passage 17, 18, respectively, and the other end in the valve chamber 19 of the pressure control valve 3. A third variable aperture 20, 21 and a fourth variable aperture 22, 2 are connected to each other in communication with each other.
3 and a fourth passage 26, 27. The other ends of the first passages 15 and 16 are connected to each other by a conduit 28, and the other ends of the second conduits 17 and 18 are connected to the conduit 28.
9, they are connected to each other in communication.

The first variable throttles 11 and 12 each have a valve chamber 1
Port 3 of first passage 15, 16 opening to 0
0, 31, and valve elements 32, 33 carried by the valve body 4 to control the increase/decrease of the opening area of the ports 30, 31, and the second variable throttles 13 and 14 each have a Second passage 17, 18
Ports 34 and 35 and port 3 supported by valve body 4
a valve element 36 for controlling the increase/decrease of the opening area of 4, 35;
37 and more familiar. Similarly, the third variable aperture 2
0 and 21 are third passages 2 that open into the valve chamber 19
4, 25 ports 38, 39 and valve elements 40, 41 supported by the valve body 5 to control the increase/decrease of the opening area of the ports 38, 39, and the fourth variable throttles 22 and 23 are connected to the valve chamber 19 Ports 42, 43 of fourth passages 26, 27 opening inward and valve body 5
The valve elements 44 and 45 are carried by the valve elements 44 and 45 to control the increase and decrease of the opening areas of the ports 42 and 43, respectively. These first to fourth variable apertures reduce the amount of aperture when the steering wheel 7 is substantially in the neutral position, and the first and fourth variable apertures reduce the amount of aperture when the steering wheel 7 is rotated in the left-turning direction of the vehicle. The second and third variable throttles are controlled by the steering wheel 7 via the steering gear box 6 so that the throttle amount is increased when the steering wheel 7 is rotated in the right-turning direction of the vehicle. It is becoming more and more like this.

Valve chamber 1 of directional control valve 2 of control valve 1
0 is a pump 46 driven by the engine in the middle
The valve chamber 19 of the pressure control valve 3 is connected to the reservoir tank 48 through a return conduit 49, and the valve chamber 19 of the pressure control valve 3 is connected to the reservoir tank 48 through a supply conduit 47 having a flow rate. . Also, the first passage 1
The other ends of the second passages 17, 16 and one end of the third passages 24, 25 are connected to one cylinder chamber 52 of the power cylinder 51 through a conduit 50, and the other ends of the second passages 17, 18 and the fourth One ends of the passages 26 and 27 are connected to the other cylinder chamber 54 of the power cylinder 51 through a conduit 53. A piston 55 defining the cylinder chambers 52 and 54 is reciprocatably housed within the housing of the power cylinder 51 and is drivingly connected to a rack bar not shown in the drawings.

Third passage 24 and 2 of control valve 1
5, first electromagnetic throttle valves 56 and 57 which increase the amount of throttle when energized are provided at positions close to ports 38 and 39, respectively, and fourth passages 26 and 27. is a second electromagnetic throttle valve 5 that increases the throttle amount when energized.
8 and 59 are provided near the ports 42 and 43.

Note that the first electromagnetic throttle valves 56, 57 and the second electromagnetic throttle valves 58, 59 are connected to the first passages 15, 1, respectively.
6 and the second passages 17 and 18, or these electromagnetic throttle valves may be provided in all of the first to fourth passages.

These electromagnetic throttle valves 56 to 59 are energized by the second
It is designed to be controlled by a control device 60 shown in the figure. The control device 60 includes a sensor 63 that outputs ON signals from terminals 61 and 62, respectively, in response to turning the steering wheel 7 left or right by a predetermined angle or more, and an electronically controlled automatic transmission. A sensor 64 that detects a downshift from a shift diagram and outputs an on signal when the automatic transmission shifts down, and a terminal 61 of the sensor 63.
an AND circuit 66 that outputs an on signal in response to the on signal from the sensor 64 and the on signal from the sensor 64;
On signal from terminal 62 of sensor 63 and sensor 6
AND circuit 65 outputs an ON signal in response to the ON signal from 4, and the ON signal output from AND circuits 66 and 65 and input to electromagnetic throttle valves 58, 59 and electromagnetic throttle valves 56, 57 is kept constant. It consists of output holding circuits 68 and 67 that hold time. The output holding circuits 67 and 68 hold the output in response to the fact that the ON signal is no longer output from the terminals 62 and 61 of the sensor 63, respectively, as shown by the imaginary lines in FIG. It may be configured to stop functioning.

In the torque steer prevention device for a power steering device configured as described above, when the steering wheel 7 is maintained at a substantially neutral position, the variable throttles 11 to 14 of the direction control valve 2 and the pressure control valve 3 are The variable throttles 20 to 23 are maintained in a state allowing free flow of oil, and the sensor 63
Since the ON signal is not output, the electromagnetic throttle valve 5
6 to 59 are maintained in an open state, thereby maintaining substantially the same oil pressure acting on both sides of the piston 55 of the power cylinder 51.

When the automatic transmission is downshifted while the steering wheel 7 is rotated by a predetermined angle or more in the left-turning direction of the vehicle, the first
As shown in the figure, the variable throttles 11 and 12 of the directional control valve 2 have their throttle amounts increased, the variable throttles 22 and 23 of the pressure control valve 3 have their throttle amounts increased, and the terminal 61 of the sensor 63 and sensor 64
An on signal is output from the electromagnetic throttle valves 58 and 59, thereby increasing the throttle amount, and the output holding circuit 17 maintains this state for a certain period of time. In this case, the oil supplied from the reservoir tank 48 to the directional control valve 2 by the pump 46 via the supply conduit 47 is supplied to the cylinder chamber 54 of the power cylinder 51 via the passages 17 and 29, the passage 18, and the conduit 53. The differential pressure between the oil pressure in the cylinder chamber 52 and the oil pressure in the cylinder chamber 52 drives the piston 55 to the right as seen in FIG. Also, the oil in the cylinder chamber 52 is transferred to the conduit 50, the passage 24, and the passage 28.
and 25, the pressure control valve 3, and the return conduit 49 to be discharged to the reservoir tank 48.

In this case, the electromagnetic throttle valves 58 and 59 provided in the passages 26 and 27 are maintained in a state where their throttle amount is increased, so that the power cylinder is increased by an amount corresponding to the increase in the throttle amount by these electromagnetic throttle valves. The pressure of the oil supplied to the cylinder chamber 54 of 51 is increased, thereby canceling out the force that causes the torque steer phenomenon.

Similarly, when the automatic transmission is downshifted while the steering wheel 7 is rotated by more than a predetermined angle in the right-turning direction of the vehicle, the amount of throttle of the variable throttles 13 and 14 of the directional control valve 2 increases. and the variable throttle 20 of the pressure control valve 3
and 21 are increased, and the electromagnetic throttle valve 5
6 and 57 are energized to increase their throttling amount, and as a result, the piston 5 of the power cylinder 51
The pressure of the oil acting on the side of the cylinder chamber 52 of No. 5 is increased, and the force that causes the torque steer phenomenon is canceled as in the case of the left turn of the vehicle described above.

Although the present invention has been described above in detail with respect to one embodiment in which the control valve is applied to a power steering device in which the control valve is a flapper valve, the present invention is not limited to such an embodiment. It will be appreciated that it is also applicable to power steering devices that are sliding valves or rotary valves.

[Brief explanation of the drawing]

Fig. 1 is an illustration showing the main parts of one embodiment of the torque steer prevention device according to the present invention, which is incorporated in a power steering device in which the control valve is a flapper valve, and Fig. 2 shows the torque steer prevention device shown in Fig. 1. FIG. 3 is a circuit diagram of a control device for controlling an electromagnetic throttle valve of the prevention device. 1... Control valve, 2... Directional control valve, 3... Pressure control valve, 4, 5... Valve body, 6...
Steering gear box, 7... Steering wheel, 8, 9... Axis line, 10... Valve chamber, 11
~14...Variable aperture, 15-18...Passage, 19
... Valve chamber, 20-23 ... Variable throttle, 24-29
...Aisle, 30, 31...Port, 32, 33...
...Valve element, 34, 35... Port, 36, 37...
...Valve element, 38, 39... Port, 40, 41...
...Valve element, 42, 43... Port, 44, 45...
... valve element, 46 ... pump, 47 ... supply conduit,
48...Reservoir tank, 49...Return conduit, 5
0... Conduit, 51... Power cylinder, 52...
Cylinder chamber, 53... Conduit, 54... Cylinder chamber, 55... Piston, 56-59... Electromagnetic throttle valve, 60... Control device, 61, 62... Terminal, 6
3, 64...Sensor, 65, 66...AND circuit, 67, 68...Output holding circuit.

Claims (1)

[Scope of utility model registration request] first and second passages that are communicatively connected to each other at one end and have first and second variable throttles in the middle; and third and fourth passages that are communicatively connected to each other and have third and fourth variable throttles in the middle, respectively, and the first to fourth variable throttles are arranged when the steering wheel is in a substantially neutral position. The first and fourth variable apertures increase the aperture amount when the steering wheel is turned in the left-turning direction of the vehicle, and the second and third variable apertures increase the aperture amount when the steering wheel is turned in the right-turning direction of the vehicle. a control valve configured to increase the amount of throttling when rotated, a reservoir tank for storing working fluid, and a supply conduit that communicates with the one ends of the first and second passages and has a pump in the middle; a return conduit that communicates and connects the reservoir tank and the other ends of the third and fourth passages; the other end of the first passage and the one end of the third passage and one of the power cylinders; and a second conduit that communicates and connects the other end of the second passage, the one end of the fourth passage, and the other cylinder chamber of the power cylinder. and first and second electromagnets, which are provided in the middle of at least one of the first and fourth passages and at least one of the second and third passages, respectively, and increase the amount of aperture when energized. When the throttle valve and the steering wheel are rotated by a predetermined angle or more in the left-turning direction of the vehicle and the transmission is downshifted, the first electromagnetic throttle valve is energized for a certain period of time in response to this, and the steering wheel is rotated by a predetermined angle or more. a control device configured to energize the second electromagnetic throttle valve for a certain period of time in response to the rotation of the vehicle by a predetermined angle or more in the right-turning direction of the vehicle and the transmission being downshifted. Torque steer prevention device for steering equipment.