JPS6228334B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a variable damping force type shock absorber using a rotary drive device.

As a conventional shock absorber of this type, there is one shown in FIG. 1, for example. That is,
1 is a tube, a piston 2 divides the inside of the tube 1 into an upper chamber 3 and a lower chamber 4, and a piston rod 5
A piston 2 is fixed to the lower end with an orifice nut 6. 7 is an orifice of the piston 2, 8 is a disc valve, and 9 is a washer. A radial hole 10 and an axial hole 11 are formed in the piston rod 5, and a hollow portion 1 of the orifice nut 6 is formed in the piston rod 5.
2 and an opening/closing orifice 13 formed in the orifice nut 6 form a passage 14 that communicates both the upper and lower chambers 3 and 4. A control rod 15 rotatably passes through the center of the piston rod 5.
A shutter 16 is fixed to the lower end of the control rod 15 within the hollow part 12 of the orifice nut 6. The shutter 16 includes a disk portion 16a and a tongue piece 1.
6b, which rotates together with the control rod 15 to open and close the opening/closing orifice 13. The upper end of the piston rod 5 protrudes from the tube 1 and is connected and fixed to the vehicle body, and the upper end of the control rod 15 is connected to a rotary drive device 17. The rotational drive device 17 includes gear trains 18 and 19,
Motor 20, potentiometer 21, and power supply 2
2, a comparator 23, and an angle setting device 24.

Thus, the rotational force generated by the rotational drive device 17 is transmitted to the shutter 1 via the control rod 15.
6, and the tongue piece 16b opens and closes the opening/closing orifice 13, thereby obtaining a high damping force due only to the orifice 7 of the piston 2, or a low damping force due to this and the opening/closing orifice 13.

However, according to such a conventional shock absorber rotation drive device 17, the reference value of the angle setting device 24 and the output from the potentiometer 21 are compared by the comparator 23, and the signal outputted by the comparator 23 is used to compare the reference value of the angle setting device 24 and the output from the potentiometer 21. The motor 20 is controlled to operate or stop the motor 20, and the rotation of the control rod 15 is controlled via the gear train 18. Therefore, this rotary drive device is
The structure was complex, there were many parts, and it was large.

Therefore, the inventor considered a rotary drive device that uses a solenoid as its drive source and rotates the control rod using the magnetic force of the solenoid.
The coil inside the solenoid generates heat, which causes
There is a risk that the coil may cause poor insulation or burnout of other electrical equipment, especially if the solenoid is operated intermittently by switching between energized and de-energized, and the switching is performed frequently within a short period of time. Since the large current for driving the solenoid acts on the solenoid repeatedly within a short period of time, there is a risk that the same heat generation as described above may occur.

The present invention has been made with attention to these points, and includes a predetermined deactivation period between activation and the next activation in the power supply circuit of a rotary drive device equipped with a solenoid that is excited and activated by switch operation. By providing a timer that sets the time and limits each operating time to a predetermined length, the time for one energization of the solenoid and the number of times of energization within a unit time are limited, thereby solving the above problem. The purpose is to solve the problem.

Hereinafter, the present invention will be explained based on the drawings. Second
Figures 3 to 3 show an embodiment in which the present invention is applied to a strut type front suspension.

First, to explain the configuration, the shock absorber tube 1 has a steering knuckle 2 at its lower end.
It is removably built into the strut tube 26 to which the strut tube 5 is fixed, forming a twin tube type consisting of an outer tube 1a and an inner tube 1b. 5 is a piston rod, the upper end of which protrudes above the tube 1, and the piston 2 is fixed to the lower end by means described below. The piston 2 divides the inside of the tube 1 into an upper chamber 3 and a lower chamber 4, and communicates between the two chambers 3 and 4 through piston orifices 27 and 28, while disc valves 8a and 8 on the upper and lower surfaces of the piston 2.
b constitutes a check valve for the piston orifices 27 and 28, and distinguishes both the orifices 27 and 28 into orifices on the extension side and the contraction side of the piston rod 5.

The lower outer periphery of the piston rod 5 has a male thread 29,
30, and a nut 31 is screwed onto the upper male screw 29, and a washer 9a, a disc valve 8a, a piston 2, and a disc valve 8 are installed on the lower side.
b. Fit the washer 9b onto the piston rod 5, and then screw the orifice nut 6 onto the male thread 30 on the lower side to fix the above-mentioned parts between the nut 31 and the orifice nut 6. The orifice nut 6 is formed by integrally molding a nut 6a and a cylindrical hollow body 6b, and an opening/closing orifice 13 facing in the radial direction is opened in the hollow body 6b. 32 is a plug that closes the lower part of the orifice nut 6.

A radial hole 10 and an axial hole 11 are formed in the piston rod 5, and these, a hollow portion 12 of the orifice nut 6, and an opening/closing orifice 13 form a passage 14 that communicates both the upper and lower chambers 3 and 4. . A control rod 15 rotatably passes through the center of the piston rod 5, and a hollow portion 1 of an orifice nut 6 is attached to the lower end of the control rod 15.
The shutter 16 is fixed within the shutter 2. Shutter 16
consists of a disk portion 16a with a hole and a tongue piece 16b integrated with the disk portion 16a, and is configured to rotate together with the control rod 15 to open and close the opening/closing orifice 13, and also controls the rotation angle of the shutter 16. A regulating protrusion (not shown) is provided protruding from the inner surface of the orifice nut 6. A coil spring 33 is compressed between the lower surface of the disk portion 16a of the shutter 16 and the upper surface of the plug 32.

A rotation drive device 17 for rotating the control rod 15 is installed at the upper end of the piston rod 5. This installation involves screwing the nut 34 and plate 36 onto the male thread at the upper end of the piston rod 5, tightening the nut 34 toward the plate 36, positioning the plate 36 in the longitudinal direction, and
and the piston rod 5, and the base 37 of the rotary drive device 17 is fixed to this plate 36 by screws 3.
This is done by stopping 8. Rotary drive device 17
consists of a base 37, two brackets 40a and 40b fixed to this with screws 39, and both brackets 4.
A pair of solenoids 4 each fixed to 0a and 40b
1a, 41b, cores 42a, 42b of each solenoid 41a, 41b, flanges 43a, 43b integral with cores 42a, 42b, both cores 42a,
42b, and is rotatable around the cores 42a and 42b, and is pivotally connected to the retractable member 44 at an eccentric position by a pin 45, and is externally fitted onto the upper end of the control rod 15 at the center position. It consists of a rotating plate 46. The upper end of the control rod 15 has a width across flats, and the rotary plate 46 is fitted onto the upper end at the center thereof, so that the two become integral in the direction of rotation.
Solenoids 41a, 41b and flanges 43a, 4
A shock absorbing washer 47 loosely fitted to the cores 42a and 42b is interposed between the cores 3b and 3b. 48a,
48b is a harness connected to the power source.

FIG. 4 shows a power supply circuit for exciting the solenoids 41a and 41b. 50 in the figure is a changeover switch, and this changeover switch 50 is connected to a power line 51 connected to a power source (not shown) and a ground line 52 (also not shown) grounded to the vehicle body. This changeover switch 50 has a changeover contact 53
, diodes 54a and 54b individually connected to both terminals 53a and 53b of this switching contact 53, and a resistor 55 connected to both diodes 54a and 54b. Then, one terminal 5 of the switching contact 53
3a is connected to a left timer 56a for exciting the left solenoid 41a shown in FIG. 2, and the other terminal 53a is connected to the right solenoid 4 shown in FIG.
It is connected to the right timer 56b for exciting the 1b. These left and right timers 56a and 56b have built-in monostable multivibrators, and when an ON→OFF input signal is input from the changeover switch 50 side, an ON output signal is output for only 2 seconds, and for the next 10 seconds, no input signal is input. It is designed to output an OFF output signal regardless of the condition.

Further, in the figure, 57a is a left relay, and 57b is a right relay, and both the left and right relays 57a,
57b consists of relay contacts 58a, 58b and coils 59a, 59b, respectively. The left solenoid 41a is connected to the relay contact 58a of the left relay 57a, and the right solenoid 41b is connected to the relay contact 58b of the right relay 57b. A relay 57a is connected between the wire 52 and the
57b, and are connected in parallel through each. and,
Resistors 60a and 60b are provided at one terminal of each of the relay contacts 58a and 58b, respectively, for supplying a small amount of power to the solenoids 41a and 41b so that the cores 42a and 42b maintain their current positions.

The bases of transistors 61a, 61b are connected to the output sides of both the left and right timers 56a, 56b, respectively.
The emitters are connected to the ground wire 52, and the collectors are connected to the coils 59 of both the left and right relays 57a and 57b.
a, 59b, respectively, and the coil 59
The other ends of a and 59b are connected to the power supply line 51, respectively.

The left side solenoid 41a shown in FIG. A circuit 62a is formed, and
Resistor 55, diode 54b, and terminal 53b
, the right timer 56b, and the transistor 61b.
, the right relay 57b, and the resistor 60b,
A right circuit 62b is formed to excite the right solenoid 41b shown in the figure.

Further, the upper part of the piston rod 5 supports the vehicle body below the rotary drive device 17. A vibration isolation mechanism and a suspension spring (not shown) are interposed between the vehicle body and the piston rod 5, and between the vehicle body and the strut tube 26. 4
A lower spring seat 9 is a component of the suspension spring, and supports the lower end of the suspension spring.

Next, the action will be explained.

FIG. 5 is a diagram showing the input/output characteristics within the power supply circuit of the rotary drive device 17. In the figure, H indicates the state when the opening/closing orifice (shown in FIG. 5) is closed and the damping force of the shock absorber is large, and S indicates the state when the opening/closing orifice 13 is opened and the shock absorber is in a large damping force. This shows the state when the damping force of the absorber is small.

First, when the ignition switch (not shown) is turned on, the contact 53 of the changeover switch 50 is connected to the terminal 53.
If it is in contact with a, this will cause the power line 5
Since power flows from the resistor 55, the diode 54a, and the terminal 53a of the switching contact 53 to the ground wire 52 side from the 1 side, the left timer 5 in the left circuit 62a
A low potential signal is input to 6a. As a result, the monostable multivibrator built in the timer 56a shifts to the non-operating side, for example, for 2 seconds.
Gives an ON output signal. Then, transistor 61
The base voltage of a increases, and from the power line 51 side,
Similarly, current flows through the coil 59a and the transistor 61a to the ground wire 52 for only 2 seconds. As a result, the coil 59 of the left relay 57a
a is activated, the relay contact 58a is turned on, and current also flows through the left solenoid 41a for two seconds. By energizing the left solenoid 41a, the core 42a engaged therewith is pulled, and at the same time, the reciprocating member 44 moves in the same direction to rotate the rotary plate 46. The rotational force of this rotating plate 46 is transmitted to the shutter 16 via the control rod 15,
The tongue piece 16b closes the opening/closing orifice 13.
As a result, both the upper and lower chambers 3 and 4 are communicated only through the orifice 7 of the piston 2, so that a high damping force is obtained.

At this time, since the right circuit 62b is not operating, the base voltage of the transistor 61b remains low, and this transistor 61b is not turned on.
Further, the coil 59b of the right relay 57b is also not excited. Therefore, since no current flows through the right solenoid 41b, it is not excited, and therefore, the movement of the reciprocating member 44 as described above is permitted.

Next, the left timer 56a that outputs the ON output signal for 2 seconds has its built-in monostable multivibrator shifted to the stable side, and thereafter maintains a non-operating time _T2 of 10 seconds. At this time, the relay contacts 58a, 58b of both the left and right relays 57a, 57b are both in the OFF state, so both the solenoids 41a, 41b are not excited, and both the cores 42
a, 42b are maintained in the state they were in when the output from the left timer 56a stopped. When the changeover switch 50 is operated after the non-operation time _T2 has elapsed, the right solenoid 41b on the opposite side to the left solenoid 41a operates in the same manner as described above.
Region X shown in FIG.
1a is excited, and region Y in the figure shows a state when the right solenoid 41b is then excited in the same manner as the left solenoid 41a.

On the other hand, once the changeover switch 50 is
I connected it to the 2a side, but both the left and right solenoids 41
If you switch to the right circuit 62b before the operating time T ₁ of 41b, which is 2 seconds, has elapsed, the operating time T ₁ and non-operating time will be changed from the time of switching.
T ₂ is started. After switching, the first left solenoid 41a is in an inactive state, so in this case as well, both solenoids 41a and 41b
Each cycle time (on: 2 seconds, off: 10
seconds) are retained. Moreover, if the changeover switch 50 is changed again within the non-operation time _T2 of the right side solenoid 41b after switching, 12 seconds have passed since the closest change from the right side circuit 62b to the left side circuit 62a. Sometimes, the left circuit 62a
is energized. Region Z shown in FIG. 5 shows this state. Therefore, as in this case,
Even if the changeover switch 50 is operated before the non-operation time _T2 has elapsed, the non-operation time of one solenoid can be maintained for at least 10 seconds.

In addition, in the embodiment, the solenoids 41a, 4
Although the control rod 15 is rotated by the reciprocating movement of the cores 42a and 42b with respect to the reciprocating movement of the cores 42a and 42b with respect to the reciprocating movement of the cores 1b, the control rod 15 can be rotated through links such as the reciprocating member 44 and the rotary plate 46. The operation of the solenoids 41a and 41b may be transmitted to the control rod 15, or the rotary solenoid may be directly connected to the control rod 15.

As explained above, in this invention, the rotary drive device includes a solenoid that is excited by switch operation, a core that is moved forward and backward by this solenoid, and a mechanism that converts the forward and backward movement of the core into the rotational movement of the control rod. This simplifies the structure of the rotary drive device and reduces the number of parts.
This has the effect that the rotary drive device as a whole can be made smaller. A predetermined non-operation time is set in the power supply circuit of a rotary drive device equipped with a solenoid that is excited and activated by switch operation, and each activation time is limited to a predetermined length. A timer has been set up to do this. Therefore, it is possible to limit the energization time of the solenoid once and the number of times it is energized within a unit time, so it is possible to prevent the continuous energization time to the solenoid from becoming prolonged, and to avoid frequent switching between energization and de-energization. It is possible to prevent the large driving current from being applied many times within a short period of time. Therefore, the heat generation of the coil inside the solenoid can be suppressed, and there is no possibility of insulation failure due to heating of the coil, and there is no risk of burning out other electrical equipment. .

[Brief explanation of the drawing]

FIG. 1A is a partially cutaway front view of a conventional shock absorber, FIG. 1B is a partially enlarged view of FIG. 3 is a plan view of the rotary drive device shown in FIG. 2, FIG. 4 is an electric circuit diagram showing an embodiment of the present invention, and FIG. 5 is a diagram showing the input/output characteristics of FIG. 4. 1...Tube, 2...Piston, 3...Upper chamber, 4...Lower chamber, 5...Piston rod, 6...
Orifice nut, 6a... nut, 6b... hollow body, 13... opening/closing orifice, 14... passage,
15... Control rod, 16... Shutter, 17... Rotation drive device, 27, 28... Piston orifice, 29, 30... Male thread, 31,
34...Nut, 36...Plate, 37...Base, 40...Bracket, 41a, 41b...Solenoid, 42a, 42b...Core, 43a, 4
3b...Flange, 44...Advancing/retracting material, 45...Pin, 46...Rotating plate, 47...Shock absorbing washer, 48a, 48b...Harness, 50...Switching switch, 51...Power line, 52 ……ground wire,
53...Switching contact, 53a, 53b...Diode, 55, 60a, 60b...Resistor, 56a, 5
6b...Timer, 57a, 57b...Relay, 5
8a, 58b...Relay contact, 59a, 59b...
...Coil, 61a, 61b...Transistor, 6
2a...Left side circuit, 62b...Right side circuit.

Claims (1)

[Claims] 1 A piston that divides the inside of the tube into two chambers, a piston rod that holds the piston at one end and projects the other end into the tube, and a rotatable piston that extends axially inside the piston rod and has an outer end that projects outside the piston rod. a control rod, a rotary drive device connected to the outer end of the control rod to rotate the control rod, a passage communicating the two chambers via the inside of the piston rod, and a passage forming a part of the passage and controlling the piston rod. In a shock absorber equipped with an opening/closing orifice formed at an eccentric position with respect to the rod, and a shutter fixed to a control rod and opening/closing the opening/closing orifice by rotation of the control rod, the rotary drive device includes a switch. It is equipped with a solenoid that is energized by operation, a core that moves forward and backward by the solenoid, and a mechanism that converts the forward and backward movement of the core into rotational movement of a control rod. A shock absorber characterized in that a predetermined non-operating time is set longer than the operating time between the actuation of the shock absorber, and a timer is provided for controlling each actuation time to a predetermined length.