JP3149720B2 - Actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator, and more particularly to an actuator suitable for a vehicle height adjusting device.

[0002]

2. Description of the Related Art There is a vehicle in which a vehicle height can be adjusted by operating a switch in the vehicle in order to enhance running performance on a rough road. Increasing the vehicle height increases the approach angle, departure angle, and ramp breakover angle, and further improves off-road driving performance. The vehicle height is increased by applying the hydraulic pressure generated by the power unit to the adjusting cylinder of the spring supporting portion of each wheel and displacing the mounting portion of the spring on the vehicle body side.

FIG. 8 shows an example of a traveling device provided with a vehicle height adjusting device. A front hub 1 is supported by a double wishbone type suspension arm 4 composed of an upper arm 2 and a lower arm 3. A torsion bar spring 5 is interposed between the frame and a frame (not shown). The torsion bar spring 5 has a front end fixed to the lower arm 3 and a rear end attached to a body frame (not shown) via a rear anchor arm 6 and an actuator 7.

At a normal vehicle height (hereinafter referred to as "normal vehicle height"), the actuator 7 is extended from its own weight, and the torsion bar spring 5, the suspension arm 4, and the front hub 1 are brought into the illustrated state. Has become. When the hydraulic pressure is applied to the actuator 7 and the actuator 7 is shortened, the position of the support point P of the rear anchor arm 6 increases, and the torsion bar spring 5 rotates in the direction of the arrow A (outside). 4
, The front hub 1 rotates in the direction of arrow B, and the vehicle height increases (hereinafter referred to as “high vehicle height”).

As shown in FIG. 9, the actuator 7 is constituted by a single-acting cylinder. The upper end of a cylinder barrel 8 is fixed to a body frame via an end bolt 11, and the lower end of a rod 9 is a rear anchor arm 6 ( 8). When hydraulic pressure is not supplied to the oil chamber 7A, the rod 9 of the actuator 7 is extended by its own weight as shown in FIG. 9A, and is held at a normal vehicle height, and when hydraulic pressure is supplied to the oil chamber 7A. As shown in FIG. 9B, the piston 10 is pushed up, the rod 9 is shortened, and the vehicle body is pushed up by the height h, so that the vehicle height becomes high. When returning from the high vehicle height to the normal vehicle height, when the hydraulic pressure is removed from the oil chamber 7A of the actuator 7, the piston 10 descends due to the own weight of the vehicle body, and the rod 9 extends. In this way, the vehicle height can be adjusted to the normal vehicle height or the high vehicle height.

[0006]

By the way, the actuator 7 having the above-mentioned conventional structure adjusts the vehicle height from a normal vehicle height to a high vehicle height in order to adjust the vehicle height to a high vehicle height by hydraulic pressure, and then maintains the high vehicle height. When trying to run for a long time, there is a risk that the vehicle height may decrease due to a decrease in oil pressure,
It is necessary to constantly supply hydraulic pressure to the actuator 7.
For this reason, it is necessary to drive the hydraulic pump at all times, and there is a possibility that fuel efficiency may be deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and after controlling an actuator to a predetermined position, the actuator is mechanically locked to the position to prevent a position shift caused by stopping the operating pressure source. It is an object to provide an actuator as described above.

[0008]

According to the first aspect of the present invention, there is provided a cylinder barrel, which is slidably inserted into the cylinder barrel and controlled to a predetermined position by at least an operating oil pressure. And a base end fixed to the piston and axially drilled from the base end on the piston side.
A rod with a hole provided , and slides axially into said hole
Is housed so that it cannot rotate relative to the inner diameter of the hole.
The lock nut is formed with a slightly smaller diameter and is locked at the open end.
And bets, is built before Symbol cylinder barrel, the base end is rotatably supported by the bottom side of the cylinder barrel, tip before
Inserted into the hole of the rod and screwed with the lock nut
Then, the lock nut is moved by rotation, and the lock nut is moved.
A lead screw for locking the rod and the rod
After the lock nut is controlled, the lock nut is
And a drive mechanism for driving the feed screw to tighten the open end . In claim 2, the rod has a shaft hole whose tip is drilled at the center of the end plate.
And slidably penetrate axially in a liquid-tight manner.
Between the piston and the end plate in the cylinder barrel
A port for hydraulic supply / discharge is located near the end plate of the formed oil chamber.
It is configured to be installed .

[0009]

According to a third aspect of the present invention, the actuator is configured such that the rod is slightly displaced immediately before the control to float the lock nut, and the feed screw can be rotated except for the load applied to the feed screw. Things .

[0011]

[Action] drive mechanism, the rod is stopped at a predetermined control position
After that, rotate the feed screw to
A lock nut is tightened to the open end of the hole to lock the rod in the control position. This allows actuaries
The motor is reliably held in the control position even if the pressure of the fluid driving the piston drops. In claim 2, the activator
The port has a port for supplying oil pressure to the oil chamber and an oil from the oil chamber.
The port is also used as a port for discharging pressure, and the oil chamber
When the oil pressure in the inside is discharged, it expands and the oil
Shortens when hydraulic pressure is supplied to the chamber.

According to the third aspect, when the locked rod is driven, the rod is slightly displaced to float the lock nut from the open end. Thereby, the load applied to the feed screw is removed, and the rotation of the feed screw becomes easy. After the load of the feed screw is released, the lock is released by rotating the feed screw, and then the rod is controlled to a predetermined position.

[0013]

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the accompanying drawings. In FIG. 1, an actuator 14 is constituted by a single-acting cylinder and has a lock mechanism 15 for mechanically fixing a piston and a rod at a desired position, and a drive for driving the lock mechanism 15, that is, a drive for locking or unlocking. And a mechanism 16. Cylinder barrel 1
A piston 18 is slidably fitted in the inside 7, and an end plate 20 is mounted on the upper end in a liquid-tight manner.

The rod 19 has a base end (lower end) at the piston 1
The end (upper end) is slidably and axially liquid-tightly slidable in a shaft hole formed in the center of the end plate 20. Further, the rod 19
Has a screw 19a engraved on the outer peripheral surface from the distal end to approximately the center, and a hole 19b from the base end to approximately the center near the axis.
Are drilled. The proximal open end 19c of the hole 19b is
It has a slightly smaller diameter. And the hole 19 of the rod 19
The lock nut 21 is accommodated in the shaft b so as to be slidable in the axial direction and not to rotate relatively. Open end 19 of hole 19b
c has a small diameter to prevent the lock nut 21 from deviating.

An oil chamber 17A is formed between the piston 18 and the end plate 20 in the cylinder barrel 17, and an oil chamber 1
A port 17a is provided in the vicinity of the upper end (near end plate 20) of 7A, and holes 17b and 17c are provided concentrically on the lower surface of the base end. A hole 17d is provided. The hole 17b has substantially the same diameter as the opening end 19c of the hole 19b of the rod 19,
c has a larger diameter than the hole 17b.

The feed screw 22 has a shaft diameter of the holes 17b and 19b.
A gear, for example, a worm wheel 23, is fixed in the vicinity of the base end 22a, and the tip of the rod 19b passes through the hole 17b with a slight gap. 19c is loosely engaged with the lock nut 22 and loosely fitted into the hole 19b. The worm wheel 23 is housed in the hole 17 c, and an end plate 25 is mounted on a base end of the cylinder barrel 17 via a spacer 24. The proximal end 22a of the feed screw 22 is
4. It is supported by the end plate 25 so as to be rotatable and immovable in the axial direction. These lock nut 21 and feed screw 2
2 constitute a lock mechanism 15.

A worm 26 meshing with the worm wheel 22 is housed in the hole 17c of the cylinder barrel 17. The rotation shaft 27 of the worm 26 slightly protrudes outward from the hole 17d of the cylinder barrel 17, and is connected to one end of the rotation shaft of a drive motor 29 via a flexible shaft 28. These worm wheels 2
3, the worm 26, the flexible shaft 28 and the motor 29 constitute the drive mechanism 16. Motor 2
Reference numeral 9 denotes a worm rotating shaft of a drive mechanism of another actuator similarly configured at the other end of the rotating shaft, which is connected via a flexible shaft to be shared.

This actuator 14 is, for example, shown in FIG.
The lower end 25a of the end plate 25 of the cylinder barrel 17 is connected to the rear anchor arm 6 by being interposed between the rear anchor arm 6 of the torsion bar spring 5 on the front wheel side and the vehicle body frame in the same manner as the actuator 7 shown in FIG. 1
The screw portion 19a at the upper end of 9 is fixed to the vehicle body frame.
Further, the motor 29 is also fixed to the body frame. In this manner, the left and right torsion bar springs on the front wheel side are disposed between the rear anchor arm and the body frame. Then, the drive motor 29 simultaneously drives each drive mechanism of the left and right actuators. The rear wheel side is configured similarly to the front wheel side.

FIG. 2 shows an example of the configuration of a hydraulic circuit of a vehicle height adjusting device to which the actuator 14 is applied. Note that front left and right actuators in the drawing are denoted by FL and FR, and rear left and right actuators are denoted by RL and RR. The hydraulic pump 31 is, for example, a motor pump. The suction port is connected to the tank 32 via an oil passage 41, and the discharge port is connected to the oil passage 4.
A solenoid valve 33 for ascending the front side (hereinafter referred to as “up”) is connected via the valve 2, and a solenoid valve 35 for the rear side up is connected to the oil passage 42 via an oil passage 43. The front and rear solenoid valves 34 and 36 for lowering (hereinafter referred to as “down”) are connected to an oil passage 46 via oil passages 44 and 45, and the oil passage 46 is connected to the tank 32. Have been.
Note that a relief valve 37 is connected between the oil passages 42 and 46.

The front left and right actuators F
The ports of the oil chambers L and FR are connected to the front-up solenoid valve 33 and the front-down solenoid valve 34, respectively, and the ports of the left and right actuators RL and RR are connected to the rear-up solenoid valves, respectively. Solenoid valve 35 and rear down solenoid valve 36
It is connected to the. Throttle valves 38 and 39 are connected to the oil passages 44 and 45 of the down solenoid valves 34 and 36, respectively.

The drive motor of the hydraulic pump 31, the front actuators FL and FR, and the rear actuators RL and R
The motor 29 (FIG. 1) and each of the solenoid valves 33 to 36 of each drive mechanism 16 of R are connected to the control device 50 (FIG. 3). The control device 50 is connected to vehicle height sensors 51 and 52 for detecting vehicle heights on the front and rear sides of the vehicle body and a vehicle height setting switch 53 for setting the vehicle height. The vehicle height setting switch 53 is provided on the driver's seat side of the dash panel, and is, for example, normal (NOR) or low (L).
O), middle (MID), and high (HI) vehicle heights can be arbitrarily set by manual operation.

The operation will be described below. First, a case in which the vehicle height is adjusted from the normal vehicle height to the high vehicle height (vehicle height is increased) will be described with reference to the flowcharts of FIGS. 1 to 4 and 5. When the vehicle height is at the normal vehicle height, the actuators FL, FR, RL, and RR (FIG. 2) are in a state of being extended by being pushed down by the weight of the vehicle body, and the hydraulic pressure of each oil chamber is eliminated. Then, as shown in FIG. 4A, the lock nut 21 of the lock mechanism 15 is
As a result, the rod 19 is tightened and pressed against the open end 19c of the hole 19b of the rod 19, thereby holding (locking) the rod 19 in an extended state. The solenoid valves 33 to 36 are deenergized and set to position 3
3A to 36A, and the hydraulic pump 31
Has stopped.

The driver operates the vehicle height setting switch 53 (FIG. 3).
Is set from the normal (NOR) position to the high (HI) position (step S1 in FIG. 5), the control device 50 drives the hydraulic pump 31 to generate a hydraulic pressure and energizes the up solenoid valves 33 and 35. To the positions 33B and 35B (step S2). The hydraulic pressure generated by the hydraulic pump 31 is adjusted to a predetermined pressure by a relief valve 37, and the actuators FL, FR, R
The actuators FL, FR, RL, and RR are shortened in addition to the oil chambers L and RR. Actuator F
L is reduced by the lock nut 21 when hydraulic pressure is applied and shortened.
Is lifted from the open end of the hole 19b of the rod 19, and the feed screw 2
2 is released (FIG. 4 (b)). This facilitates the rotation of the feed screw 22.

Next, the motor 29 (FIG. 1) is driven (step S3), and the feed screw 22 rotates to lower the lock nut 2 by following the shortening of the rod 19 of the actuator FL. Other actuators FR, RL, RR
The same applies to. The vehicle height gradually increases as the actuators FL, FR, RL, RR are shortened.

The vehicle height sensors 51 and 52 detect the vehicle height and output a corresponding vehicle height signal. The control circuit 50 determines whether or not the vehicle height has reached a predetermined height (high vehicle height) (step S4).
2, when the predetermined height is reached, the solenoid valves 33, 3
5 is deenergized and switched to the positions 33B and 35B, and the hydraulic pump 31 is stopped (step S5). As a result, the actuator FL stops at the position as shown in FIG. The feed screw 22 is still rotating, and FIG.
As shown in (d), the lock nut 21 is tightened and pressed against the open end 19c of the hole 19b of the rod 19 to lock the rod 19. The motor 29 is a lock nut 2
1 tightens and locks the open end 19c of the rod 19, and automatically stops when the load increases (step S6).
As a result, the rod 19 is held at the shortened position. The same applies to the other actuators FR, RL, RR. In this way, the vehicle height is adjusted to the high vehicle height position.

Actuators FL, FR, RL, RR
Are mechanically locked by the lock mechanisms 15, respectively, so that they are held at the predetermined positions even if the oil pressure in each oil chamber drops due to leakage or the like. Thus, even if the hydraulic pump 31 is stopped after adjusting from the normal vehicle height to the high vehicle height, the high vehicle height can be reliably maintained for a long time.

Next, a case where the vehicle height is adjusted from the high vehicle height to, for example, a middle vehicle height (vehicle height down) will be described with reference to the flowcharts of FIGS. The actuators FL, FR, RL, and RR are adjusted to the high vehicle height position as described above, and are supported by the feed screw 22 while being locked by the lock mechanism 15. (Body weight) (FIGS. 4D and 6A).

When the vehicle height setting switch 53 is set from the high (HI) position to the middle (MID) position (step S10 in FIG. 7), the control device 50 drives the hydraulic pump 31 and simultaneously operates the solenoid valves 33 and 34. To the position 33B,
35B (step S11), and after supplying hydraulic pressure to the actuators FL, FR, RL, RR to slightly reduce the pressure, the hydraulic pump 31 is immediately stopped, and the solenoid valves 33, 35 are deenergized so that the position 33A, Switch to 35A (step S12). As a result, as shown in FIG. 6B, the rod 19 slightly descends, the lock nut 21 floats, and the load on the screw 22 is released. This facilitates the driving of the screw 22. In addition, from step S11 to step S1
The control to 2 is for a very short time (for a moment). Next, the control device 50 drives the motor 29 to rotate the feed screw 22 (step S13), raises the lock nut 21 to release the lock, and simultaneously performs the down solenoid valves 34 and 36.
To switch to the positions 34B and 36B (step S14).

Actuators FL, FR, RL, RR
The rod 19 is unlocked and the solenoid valve 34,
When the position 36 is switched to the position 34B, 36B, the pressure is extended while pushing out the oil pressure in the oil chamber by the weight of the vehicle body. The hydraulic pressure extruded from the actuators FL, FR, RL, RR flows to the tank 32 through the oil passages 44, 45, and 46. At this time, the flow rate of the hydraulic pressure flowing through the oil passages 44 and 45 is limited by the throttle valves 38 and 39, and the actuator slowly expands. As a result, the vehicle height gradually decreases. Control device 50 determines whether or not the vehicle height has reached the set height (middle vehicle height) based on signals from vehicle height sensors 51 and 52 (step S15). If the vehicle height has not reached the set height, control proceeds to step S14. When returning to the set height (middle vehicle height), the solenoid valves 34 and 36 are deenergized and the position 3
Switching to 4A and 36A (step S16).

Actuators FL, FR, RL, RR
Stops when the solenoid valves 34, 36 are switched to the positions 34A, 36A (FIG. 6 (c)). The feed screw 22 is rotating, and the lock nut 21 is
Hole 19b is separated from the opening end 19c. After switching the solenoid valves 34 and 36 to the positions 34A and 36A, the control device 50 drives the motor 29 in the reverse direction (step S1).
7) The feed screw 22 is rotated in the reverse direction, and the lock nut 21 is lowered. Then, when the lock nut 21 is tightened and pressed against the opening end 19c of the hole 19b of the rod 19,
The motor 29 stops (step S18). Thereby, the actuators FL, FR, RL, RR are mechanically locked at the predetermined position (middle vehicle height).

Actuators FL, FR, RL, RR
Are mechanically locked by the lock mechanisms 15, respectively, so that even if the oil pressure in each oil chamber is reduced due to leakage or the like, the vehicle is held at the middle vehicle high position. Thereby, even if the hydraulic pump 31 is stopped after adjusting from the high vehicle height to the middle vehicle height, the middle vehicle height can be reliably maintained for a long time.

The above operation has been described centering on the high vehicle height and the middle vehicle height. However, when the vehicle is adjusted to the normal vehicle height, the vehicle is mechanically locked similarly. In the above-described embodiment, the case where the vehicle height is used for the purpose of improving the running performance of the vehicle by increasing the vehicle height has been mainly described. However, the vehicle height is reduced to improve the operability of the vehicle. It may be used for the purpose.

[0034]

According to the first aspect, as described above,
After controlling the actuator to a predetermined position, the drive mechanism
Turn the feed screw and lock nut to the control position
By mechanically locking the rod to the
Even if the hydraulic pressure in the hydraulic chamber formed by the cylinder barrel and the piston decreases due to leakage or the like, the piston is mechanically locked at the predetermined position after being controlled to the predetermined position, and thus is maintained at the predetermined position. Also, there is no need to supply an operating pressure after control. Further, since the actuator is mechanically locked, the displacement is prevented . Change
In, control it is not necessary to supply hydraulic pressure after your disappears, it is possible to stop the operation pressure source, it is possible to save energy.

[0035] In 請 Motomeko 3, when driving the rod is locked, by floating the lock nut from the open end to displace slightly the rod immediately before, is excluded that the load rests on the feed screw It can be easily rotated. This facilitates unlocking by the drive mechanism.

[0036]

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing an embodiment of an actuator according to the present invention.

FIG. 2 is a hydraulic control circuit diagram of a vehicle height adjusting device to which the actuator of FIG. 1 is applied.

FIG. 3 is a configuration diagram of a control device of the hydraulic control circuit of FIG. 2;

FIG. 4 is an explanatory diagram showing an operation of an actuator when the vehicle height is adjusted from a normal vehicle height to a high vehicle height in the vehicle height adjusting device of FIG. 2;

5 is a flowchart showing a control procedure of an actuator when the vehicle height of the vehicle height adjusting device of FIG. 2 is adjusted from a normal vehicle height to a high vehicle height.

FIG. 6 is an explanatory diagram showing an operation of an actuator when the vehicle height is adjusted from a high vehicle height to a middle vehicle height in the vehicle height adjusting device of FIG. 2;

7 is a flowchart showing a control procedure of an actuator when adjusting the vehicle height of the vehicle height adjusting device of FIG. 2 from a high vehicle height to a middle vehicle height.

FIG. 8 is a perspective view of an essential part showing an example of a vehicle height adjusting device.

FIG. 9 is an explanatory diagram of an actuator in a conventional vehicle height adjustment device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Front hub 2 Upper arm 3 Lower arm 4 Suspension arm 5 Torsion bar spring 6 Rear anchor arm 14 Actuator 15 Lock mechanism 16 Drive mechanism 17 Cylinder barrel 18 Piston 19 Rod 20 and 25 End plate 21 Lock nut 22 Feed screw 23 Worm wheel 26 Worm 28 Flexible shaft 29 Motor 31 Hydraulic pump 33-36 Solenoid valve 37 Relief valve 38, 39 Throttle valve 41-46 Oil passage 50 Control device 51, 52 Vehicle height sensor 53 Vehicle height setting switch

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F15B 15/00-15/28

Claims (3)

(57) [Claims] 1. A cylinder barrel, a piston slidably inserted into the cylinder barrel and controlled at a predetermined position by at least hydraulic pressure, and a base fixed to the piston and a shaft from the piston side base.
A rod with a hole drilled in the direction, and housed in the hole so as to be slidable in the axial direction and relatively non-rotatable
The opening end is formed slightly smaller in diameter than the inner diameter of the hole.
A lock nut locked into the cylinder barrel; a base end rotatably supported at the bottom side of the cylinder barrel ;
Screwed into the lock nut and
Move the lock nut to lock the rod.
And after the rod is controlled to the predetermined position,
Lock nut in position to tighten the open end
A drive mechanism for driving the feed screw . 2. The rod has a distal end drilled at the center of an end plate.
Is slidably penetrated in the axial direction in a liquid-tight manner
Also, between the piston and the end plate in the cylinder barrel
Hydraulic supply / discharge port near the end plate of the oil chamber
The actuator according to claim 1, wherein the actuator is disposed.
Eta. 3. The actuator displaces the rod slightly just before control to lift the lock nut,
The actuator according to claim 1 , wherein rotation of the feed screw is enabled except for a load applied to the feed screw.