JPS5878813A - Shock absorber control device at selection of driving shift position of automatic car - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention increases the damping force of shock absorbers (particularly hydraulic shock absorbers) when selecting a drive shift position in an automatic vehicle, thereby changing the drive shift position before starting the vehicle. This invention relates to a device that can obtain shock absorber A characteristics that match selected conditions.

As is well known, the suspension of vehicles has a mechanism that uses hydraulic shock absorbers, and when used alone or in combination with other springs, etc., it is possible to improve vehicle ride comfort and maneuverability. It becomes possible to obtain the Susvenge Sword.

Typical hydraulic shock absorbers include a hydraulic piston interposed between the vehicle body side and the wheel side, and its damping force is always kept constant under certain conditions. That is,
The damping force is normally determined by the cross-sectional area of an orifice that flows through two hydraulic chambers separated by a piston, and in conventional devices, the flow cross-sectional area of this orifice is constant, so under certain conditions. The damping force was always kept constant.

However, with such a constant damping force, it is not always possible to achieve the optimal shock absorption effect when the vehicle is actually running, and according to the results of recent vehicle running experiments, the damping force It has been concluded that it is preferable to vary the damping force of the shock absorber nose.

In particular, in the conventional short shock absorber nose mechanism mentioned above, its setting is adapted to normal constant speed driving conditions, so when the drive shift position is selected before starting the vehicle in an automatic car, the shock absorber nose is rotated. The drawback was that the vehicle body would crouch down to support the added driving force.

The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to provide a device that can increase the damping force of a shock absorber in a drive position selection state before starting a vehicle.

In order to achieve the above object, the present invention provides a variable orifice that is incorporated into a hydraulic shock absorber and whose flow cross-sectional area can be adjusted to be small in order to increase the damping force of the shock absorber, and A solenoid inserted into the shock absorber to change the flow cross-sectional area, a shift sensor that detects the neutral shift position of the transmission mechanism, a start sensor that electrically detects the start of vehicle travel, and a neutral shift position signal. and detects the drive shift position standby state of the vehicle from the start signal and adjusts the drive shift position of the vehicle.
and a control circuit that excites the variable orifice to reduce the flow cross-sectional area of the variable orifice, and temporarily increases the damping force of the shock absorber 79 in a drive shift position selection state before starting the vehicle. .

Preferred embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a preferred embodiment of a hydraulic shock absorber 9 mechanism of a variable shock absorber nozzle device suitable for the present invention.

The cylinder/1°0 of each shock absorber includes an inner cylinder 12 and an outer cylinder 14, and a hydraulic reservoir 200 is formed between the cylinders 12 and 14. A bottom plate 16 is hermetically fixed to the lower end of the outer cylinder 14, and a top plate 18 is similarly hermetically fixed to the upper end. The inner cylinder 12 is housed and held within the outer cylinder 14 by a bottom holder/2G fixed to its lower end and a top holder/22 fixed to its upper end.

A piston 24 is provided in the inner cylinder 12 of the cylinder//10 so as to be slidable in the axial direction, and the inside of the inner cylinder 12 is isolated by the piston 24 into a first hydraulic chamber 202 and a second hydraulic chamber 204. has been done.

The piston 24 is fixed to one end of the piston rod 26, and the other end of the piston rod P26 extends outward from the upper end of the cylinder IO. An oil seal 28 is provided between the piston P26 and the top plate 18 of the outer cylinder 14, and when the piston rod 126 slides in the axial direction with respect to the cylinder/1G, the oil seal 28 is connected to the hydraulic pressure chamber 200. This prevents the pressure oil filled in the first hydraulic chamber 202 and the second hydraulic chamber 204 from leaking.

The piston 24 is provided with a fixed orifice 30 on the extension side and a variable orifice 32 on the extension side, and a contraction side check A-lube 31 is engaged with these two orifices 30, 32 to determine the flow direction thereof. Similarly, bottom hole /20
is provided with a fixed orifice 33 on the contraction side, a variable orifice 34 on the contraction side, and a check knob 35 on the expansion side. Therefore, when the piston 24 extends upward with respect to the cylinder 10, the oil in the first hydraulic chamber 202 moves to the second hydraulic chamber 204 through the fixed orifice 30 on the extension side and the variable orifice 32 on the extension side. The damping force is determined by the flow cross-sectional area of the fixed orifice 30 on the extension side in the low-speed range, and determined by the flow cross-section area of the variable extension-side orifice 32 in the middle and high speed ranges. Similarly, when the piston 24 contracts downward relative to the cylinder/10, the second hydraulic chamber 2
04 oil flows through the compression side fixed orifice 33 and the compression side variable orifice 34 to the first hydraulic chamber 202, and the damping force at this time is the damping force of the compression side fixed orifice 33 in the low speed range, and the compression side in the medium and high speed range. They are each determined by the flow cross-sectional area of the variable orifice 3.4.

When the piston 24 expands and contracts, both hydraulic chambers 202°20
Oil from the hydraulic reservoir chambers 200 can also flow to the inner cylinder 12, and for this purpose, the bottom holder 20 and the top holder 22 provided at the lower end of the inner cylinder 12 are provided with predetermined communication holes. ing.

The structure of the basic hydraulic shock absorber mechanism explained above is the same as the conventional one, but in this LI, a variable orifice and a Renoir for operating this variable orifice are incorporated in the shock absorber nose. It is characterized by the presence of

That is, the outer cylinder 14 of the cylinder/10 has an open tube 14 formed on its side surface, and a plug 38 is airtightly fixed to the open tube 14m.

[The plug 38 is provided with a variable orifice 40 parallel to the axial direction of the cylinder 10. A hydraulic reservoir chamber 2 is located between one end of the variable orifice 40 and the top hole/22.
A conduit 42 passing through the ring holder 22 is connected and fixed, and the top end of the conduit 42 is connected to the communication port 2 formed in the ring holder 22.
It is connected to the first hydraulic chamber 202 via 2 m. Further, the other end of the variable orifice 40 is connected to a hydraulic lizard nozzle 20.
0 to the second hydraulic chamber 204.

The plug 38 has a slot 38 that crosses the variable orifice 40 in a direction perpendicular to the variable orifice 40! The flow cross-sectional area of the variable orifice 40 can be adjusted by changing the amount of blockage of the slot 38.

In order to change the amount of blockage of the slot 38m, in the present invention, the solenoid r A core 48 is fixed to the case 46, and a coil 5 is arranged around the core 48.
0 is fixed by winding. A plunger 52 is slidably housed in the core 48 and the plug 38 along the axis of the solenoid 44, and a valve portion 52m provided at the tip of the plunger 52 is inserted into the slot 381 of the plug 38. The flow cross-sectional area of the variable orifice 40 is adjusted by the sliding position of the valve portion 52m.

In this embodiment, the valve portion S2m of the plunger 52 is provided with an open groove 53 on its side surface, and when the coil 50 is in a non-energized state, the IC1 open groove 53 is formed as shown in FIG.
is opposed to the variable orifice 40, and the shock absorber is opposed to the orifice 3 provided in the piston 24.
The damping force is determined to be a constant value by the flow cross-sectional area of 0.32 or 33.34 and the variable orifice 40.

Then, the excitation circuit connected to the coil 50 - P wire 5
6, the plunger 52 is supplied with an excitation current through the first
When the variable orifice 40 is suction-moved to the left in the figure against the spring 5"4, the variable orifice 40 is closed by the valve portion 52m.
In this state, the shock absorbers have a small flow cross-sectional area determined by the orifice 30.degree. 32 or 33.34, making it possible to temporarily change and adjust the damping force to a large extent.

Therefore, by energizing the solenoid coil 50 only when the vehicle is in a predetermined state, for example, in a drive shift position selection state before starting the vehicle, it is possible to obtain a good ride comfort. It is detected based on two conditions: the shift position of the transmission mechanism and the vehicle speed.

FIG. 2 shows a shift sensor 6G suitable for the present invention.

A start sensor 62 and control circuit 64 are shown.

The shift sensor 60 is provided in the transmission mechanism to detect a neutral shift position of the transmission mechanism, that is, a position other than the drive shift position such as parking or neutral. In this embodiment, the shift sensor 60 is turned on at the neutral shift position of the transmission mechanism. The neutral start switch 66 outputs a neutral shift position signal 400 rLJ.

On the other hand, the start sensor 62 is configured as follows in order to electrically detect the start of running of the vehicle.

That is, in order to electrically detect the running speed of the vehicle, the start sensor 62 includes a vehicle speed sensor 68, and the vehicle speed sensor 68 is composed of a rotor magnet and a Lee P switch that interlock with the wheels, and outputs a pulse signal with a frequency corresponding to the vehicle speed. is output as a vehicle speed signal 402. A differentiation circuit 72 is provided on the output side of the vehicle speed sensor 68, and a differentiation circuit 72 is provided on the output side of the differentiation circuit 72, and a vehicle acceleration comparison circuit 74 is provided on the output side of the differentiation circuit 72. operational amplifier 76,
The vehicle acceleration comparison circuit 74 is composed of a resistor 78, 80, a capacitor 82, and an operational amplifier 84, a resistor 86, and a variable resistor 88.

[The vehicle speed signal 402 is converted into a voltage signal by the F/V converter F0, and then differentiated by the differentiation circuit 72 and detected as vehicle acceleration.
The gate signal 404 is compared with the reference acceleration and becomes rHJ when the predetermined acceleration is reached.
Output to 0.

Further, the vehicle speed signal 402 converted into a voltage signal by the P/V converter 70 is output to the operational amplifier 92, and when the vehicle is running, the operational amplifier 92 outputs r to the AND gate 90.
A gate signal 406 HJ is output. Therefore, when the vehicle is running and the vehicle acceleration reaches a predetermined value,
That is, when the steady running state is reached, the gate signal 404.
406 are both output to AND gate 9G, so the AND gate 90 outputs a start signal 408 of "■".

Next, the first control circuit 64 detects the drive shift position standby state of the vehicle from the neutral shift position signal 400 and the start signal 402, and excites the coil 50 of the solenoid 44 to control the flow cross section of the variable orifice 40 to decrease. The system is configured as described below.

That is, the neutral shift position signal 400 from the neutral start switch 66 is connected to the resistor 94 and the neutral shift position signal 400 from the neutral start switch 66.
Flip-flop (hereinafter referred to as "FFJ") through 6
・It is supplied to the set input of 98, and when the transmission mechanism is shifted to the neutral shift position, the shift sensor 60 to FF9
The set input of B has a neutral shift position signal 40 called rHJ.
Since 0 is supplied, the Q output of FF98 becomes rHJ. In addition, a coil excitation circuit 100 is connected to the Q output side of the PP98.
In the embodiment, the coil excitation circuit 100 includes transistors 102 and 104 connected in series, resistors 106 and 108, and a diode 11 for absorbing back electromotive force.
The transistors 102 and 104 are turned on by the Q output rHJ of the flip-flop 98, and supply an excitation current to the solenoid coil 50 for a predetermined time. Further, the start signal 408 of the start sensor 62 is supplied to the reset input of the %FF 98, and the FF 98 is reset when the vehicle is running and the vehicle acceleration reaches a predetermined value, that is, when the vehicle is in a steady running state.

The embodiment of the present invention has the above configuration, and its operation will be explained below.

When the vehicle is started, the transmission mechanism is in the neutral shift position.
In this state, the vehicle is in a standby state for the drive shift position for the next start, and in the conventional device, crouching occurred when selecting this drive shift position.

A feature of the present invention is that the damping force of the shock absorbers is increased in this drive shift position standby state, thereby preventing squatting during the next drive position selection.

That is, when the decay mechanism is shifted to the neutral shift position, a neutral shift position signal 400 of rHJ is supplied from the shift sensor 60 to the set input of the FF 98, and a Q output signal of "H" is output from the FF 98 to the coil excitation circuit 100. Therefore, an excitation current is supplied to the coil 50 of the coil t'44. Therefore, the syringer 52 of the variable shock absorber shown in FIG. 1 is sucked and moved to the left in FIG.
is closed by the valve portion 52m, and in this state, the pump opening device has a flow cross-sectional area equal to that of the orifice 30.m.
It will be a small area determined by 32 or 33.34,
The damping force can be temporarily changed and adjusted. Therefore, since the damping force of the shock absorber is increased, it is possible to prevent the vehicle from squatting in the position selection state (driving 77) before starting the vehicle.

Then, when the vehicle is running and the vehicle acceleration reaches a predetermined value, that is, when the vehicle is in a steady running state, gate signals 404 and 406 are both output to the AND gate 90. A start signal 408, which is the reset input ICrHJ, is supplied. As a result, a Q output signal rHJ is output from the FF 98 to the coil excitation circuit 100, and the supply of excitation current flowing to the coil 50 of the solenoid 44 is cut off, so that the variable orifice 40 of the variable shock absorber is opened again. The damping force becomes small again, and it is possible to prevent the occurrence of the J-horn feeling while driving.

As explained above, according to the present invention, crouching can be reliably prevented by temporarily increasing the damping force of the shock absorber 9 in the driving position selection state K before the vehicle starts. In addition, during steady driving, it is possible to restore the damping force of the shock absorbers to the normal state and create a stable driving condition.

In the present invention, the shock absorber/sensor mechanism that controls the damping force may be provided on the four wheel metal parts, or it may be provided only on the rear wheels that have a large effect on the squatting phenomenon, and these installations may be It is preferable that an arbitrary number of control circuits 64 be arranged in parallel in accordance with the number of control circuits 64.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a shock absorbing mechanism suitable for the device of the present invention, and FIG. 2 is a circuit diagram showing a shift sensor, a start sensor, and a control circuit suitable for the present invention. lO...Cylinder, 12...Inner cylinder, 14...Outer cylinder, 24-Piston 1, 40°°°1 change'''979', 60...Shift sensor, 62-...Start Senna, 6.4...Control circuit.

Claims (1)

[Claims] (1) A variable orifice that is incorporated into hydraulic shock absorbers to increase the damping force of the shock absorber (in order to reduce the flow cross-sectional area and adjust the flow cross-section of the variable orifice) A solenoid is built into the shock azoso/RE, a shift sensor detects the neutral shift position of the transmission mechanism, a start sensor electrically detects the start of the vehicle, and a neutral shift position signal and a start signal are used. a control circuit that detects the drive shift position standby state of the vehicle and excites the sonnoy P to control the flow cross-sectional area of the variable orifice to be reduced; A shock absorber nose device for selecting a drive shift position in an automatic vehicle, which is characterized by temporarily increasing the damping force of the vehicle.