JP2531286Y2 - Cylinder device for rear wheel steering device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial Application Field >> The present invention relates to a rear wheel steering device, and more particularly to a cylinder device of a rear wheel steering device capable of adjusting a stroke amount of a piston inside a cylinder.

<< Conventional Technology >> Recently, as the sophistication of vehicles has advanced, high demands have also been imposed on the traveling performance, and the rear wheels are steered according to the turning of the front wheels,
Particularly, attempts have been made to improve the steering stability of the vehicle at the time of cornering or the like, and a rear wheel steering device having such a rear wheel steering function has been developed.

As a cylinder of this kind of conventional rear wheel steering device, for example, there is a cylinder described in Japanese Patent Application Laid-Open No. 61-81869. In the cylinder of the rear wheel steering device, a pair of liquid chambers is provided inside the cylinder, the liquid chambers are partitioned, springs are provided in the respective liquid chambers, and the piston is held at a neutral position by the urging force of these springs. . A rod is connected to the piston and extends outside through the cylinder. The rod slides with the piston to steer a rear wheel connected to the rod. A rod cover is inserted through both ends of the rod. The rod cover seals the liquid chamber and slidably supports the rod.

<< Problems to be Solved by the Invention >> However, in the cylinders of the above-described conventional rear wheel steering devices, springs are provided in the respective liquid chambers, and when no differential pressure is generated between the liquid chambers, these springs are used. The configuration was such that the piston was held at the neutral position by the biasing force. Therefore, if springs having different spring constants and set loads are provided, or if there is a variation in the accuracy of assembling the piston and the rod, the neutral position of the piston moves, and the neutral position moves outward from both left and right end surfaces of the cylinder. The length of the left and right ends of the rod extending to the right and left ends is not equal to each other, the position of the rear wheel connected to the rod is shifted left and right, the straight running performance of the vehicle is reduced and the rear wheel is not properly steered during cornering There was a problem.

In order to make the lengths of the right and left ends of the rod extending outward from the left and right ends of the cylinder equal to each other, an additional mechanism for adjusting the stroke may be provided in the cylinder itself. There has been a problem that the number of assembling man-hours increases, which in turn leads to an increase in product cost.

The present invention has been made in view of such a conventional problem. The purpose of the present invention is to provide an adjusting means for adjusting the stroke amount of the piston so as to reduce the stroke amount of the piston in the left-right direction. Equally, the straight running stability and the steering stability of the wheels connected and steered at both ends of the rear wheel steering device are improved, and the cost of the product is reduced by simplifying the adjusting means. It is intended to provide a cylinder of a rear wheel steering device that can be used.

<< Means for Solving the Problems >> In order to achieve the above object, a cylinder device of a rear wheel steering device according to the present invention seals an open end of a cylinder with a rod cover and a power rod in the cylinder. A rear wheel of a vehicle that slidably accommodates a piston, defines a pair of liquid chambers in the cylinder, and holds the piston at a neutral position by an urging force of urging means provided between the liquid chambers. In the steering device, side rods respectively connected to both ends of the power rod with stroke adjustment means for adjusting the stroke amount in the left-right direction from the neutral position of the piston with an adjustment plate and the number of shims held by the adjustment plate. And the rod cover.

<Operation> Therefore, in the cylinder device of the rear wheel steering device according to the present invention, since the adjustment of the stroke amount from the neutral position of the piston to the left and right can be performed by the adjustment plate interposed with the shim, the deviation of the stroke amount is appropriately corrected. Along with
This stroke adjusting means can be simplified.

<< Embodiment >> An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a longitudinal sectional view showing one embodiment of a cylinder device of a rear wheel steering device according to the present invention. In FIG. 1, reference numeral 1 denotes a rear wheel steering device. The rear wheel steering device 1 has a piston 3 slidably housed in a cylinder 2. The piston 3 divides the inside of the cylinder 2 into a pair of liquid chambers 4,5, and the open ends of the liquid chambers 4,5 are sealed by rod covers 6,7. A connection hole 3a and a through hole 6a, 7a are formed at the axial center of the piston 3 and the rod covers 6, 7, respectively.
And a power rod 8 that fits in the through hole 6a, 7a
Is provided. The power rod 8 is integrated with the piston 3 and slides at the same time as the piston 3 slides. The power rod 8 has side rods 9 and 10 connected to both ends thereof, and further has tie rods 11 and 1 attached to the side rods 9 and 10.
2 are linked. Also, a concave portion 3b is formed on the outer peripheral portion of the piston 3.
Are formed, and the seal link 13 is fitted in the concave portion 3b. Oil tightness between the power rod 8 and the rod covers 6, 7 is maintained by the shaft seals 14, 15. Springs 16 and 17 are provided in the liquid chambers 4 and 5, respectively, and the piston 3 is held at a neutral position by the urging force of the springs. ing. Reference numerals 18 and 19 are guide plates, and the guide plates 18 and 19 are the pistons 3 with the biasing force of the springs 16 and 17.
The springs 16 and 17 are positioned so as to act equally on. The connectors 20 and 21 are respectively attached to portions communicating with the respective liquid chambers 4 and 5 of the cylinder 2.
Reference numerals 20 and 21 are connected to a front-wheel steering actuator and the like (not shown) via a pipe and a direction switching valve and the like, so that high-pressure hydraulic fluid flows into and out of the respective fluid chambers 4 and 5. Due to the inflow and outflow of the working fluid, the pressure in the liquid chamber 4 and the pressure in the liquid chamber 5 increases or decreases, and a differential pressure is generated between the liquid chambers 4 and 5. When this pressure difference exceeds the biasing force of the springs 16 and 17, the piston 3
Slides and the power rod 8 slides, and the side rods 9 and 10 and the tie rods 11 and 1 connected to both ends of the power rod 8 slide.
The rear wheels (not shown) are steered through the control unit 2. The stroke amount (illustrated) of the sliding piston 3 is adjusted by stroke adjusting means provided at the respective open ends of the rod covers 6 and 7.

This stroke adjusting means is composed of adjusting plates 22, 23 and shims 24, 25, as shown in FIGS. The adjusting plates 22, 23 have a pair of legs 22a formed on the adjusting plates 22, 23, and the legs 22a are bent so that they are parallel to each other. This leg 22a has a rod cover
The heads 6b, 7b are formed to have a width that can be inserted into the grooves 6a, 7a formed in the heads 6b, 7b, and the leg 22a is provided with a hole 22b. Then, the adjusting plates 22 and 23 insert the legs 22a into the grooves 6a and 7a, penetrate the screws 100 through the holes 22b of the adjusting plates 22 and 23, and
It is attached to the rod covers 6, 7 by screwing it into a screw hole 6c formed in a, 7a. Then, the shims 24, 25 are interposed between the adjusting plates 22, 23 and the opening end faces of the rod covers 6, 7, and the shims 24, 25 are attached when the adjusting plates 22, 23 are attached to the rod covers 6, 7. .

That is, as shown in FIGS. 1 and 2, the outer end faces of the adjusting plates 22 and 23 and the side rods 9 and
The distance until the 0 end faces 9a and 10a come into contact is set as a stroke amount, and the end faces are used as stoppers. Further, the above-mentioned shims 24, 25 are used for adjusting the stroke amount.
Function together with the adjustment plates 22 and 23 as stroke adjustment means as a whole.

In FIG. 1, reference numerals 26, 27 and 28 denote fixing plates for fixing the rear wheel steering device 1 to a vehicle or the like, and 29 and 30 denote air vent valves.

Also, adjust plates 22 and 23 to rod covers 6 and 7 with screws 10
After mounting at 0, the tips of the legs 22a may be bent inward as shown by the dotted line in FIG. 5, so that the adjustment plates 22, 23 can be further mounted on the rod covers 6, 7. Be certain. However, in this case, adjustment plates 22 and 2
The length L of the third leg 22a and the distance l from the tip of the leg 22a to the hole 22b must have adjusting plates 22, 23 of a type corresponding to the thickness of the shims 24, 25 used.

Therefore, the adjusting plates 32, 33 shown in FIG. 6 are inserted into the grooves 6a, 7a of the rod covers 6, 7 after the legs 32a of the adjusting plates 32, 33 are inserted, and then the legs 32a are bent inward, whereby the rod cover 6 is bent. , 7 can be easily mounted, and the adjustment plates 32, 33 need not be aligned.

Further, the adjusting plates 42 and 43 shown in FIG. 7 are provided with holes 42b in the directions of the grooves 6a and 7a of the rod covers 6 and 7 in accordance with the thickness of the shims 24 and 25. Since the adjustment plates 42 and 43 can be moved by the distance, there is no need to align the adjustment plates 42 and 43
Since it can be fixed at 00, the rod covers 6, 7 of the adjustment plates 42, 43 are securely attached.

Further, as shown in FIG. 8, a plurality of screw holes 6c of the rod covers 6, 7 are formed in the grooves 6a, 7a, so that the adjusting plate 2 is formed.
The adjustment plates 22, 23 can be more securely attached to the rod covers 6, 7 without aligning them in various ways.

The shims 34 and 35 shown in FIG. 9 are formed in a substantially C shape, and are provided with openings 34a through which the side rods 9 and 10 can be inserted and removed. By using the shims 34, 35, the shims 34, 35 can be replaced without removing the adjustment plates 22, 23, 32, 33, 42, 43 of FIGS. 5 to 7 from the rod covers 6, 7. .

An adjusting plate as shown in FIGS. 10 and 11
The openings 52c are provided in the 52 and 53 similarly to the shims 34 and 35. In the case of FIG. 10, after the shim 34 is inserted, the legs 52a of the adjustment plates 52, 53 are inserted with the legs 52a raised, and then the legs 52a are inserted into the grooves 6a, 7a of the rod covers 6, 7. like,
By bending inward, the adjustment plates 52, 53 can be attached to the rod covers 6, 7 without removing the side rods 9, 10.

In the case of FIG. 11, the portions corresponding to the grooves 6a, 7a of the rod covers 6, 7 are chamfered 6d, 7d so that the legs 52a of the adjustment plates 52, 53 are bent inward in advance, and the side rods 9 are bent. The adjustment plates 52 and 53 can be attached to the rod covers 6 and 7 without removing the and.

 Next, the operation will be described.

The front wheel is steered by operating the front wheel steering actuator (not shown) according to the steering force of the steering wheel (not shown), and the high-pressure hydraulic fluid generated at this time is piped by operating the direction switching valve and the like. (Not shown) and connector 20
When the liquid flows into the liquid chamber 4 through the, the liquid pressure in the liquid chamber 4 increases. At this time, the hydraulic fluid does not flow into the liquid chamber 5, and only the urging force of the spring 17 acts. Therefore, when the liquid pressure in the liquid chamber 4 rises, a liquid pressure difference is generated between the liquid chamber 4 and the liquid chamber 5, and when the pressure difference exceeds the urging force of the spring 17, the piston 3 moves in the figure. It moves to the right and the rear wheels are steered. On the other hand, when high-pressure hydraulic fluid flows into the liquid chamber 5 from the connector 21, the piston 3 moves to the left in the figure,
The rear wheels are steered in the opposite direction. Liquid chamber 4 in the direction of movement,
The hydraulic fluid in 5 is connected to connector 2 according to the amount of movement of piston 3.
Outflow from 0,21. In these cases, the stroke amount of the piston 3 is limited by the adjusting plates 22 and 23 and the shims 24 and 25. Next, the inflow of the hydraulic fluid stops, and the liquid chambers 4, 5
When the internal fluid pressure decreases, the piston 3 returns to the neutral position by the urging forces of the springs 16 and 17, and the rear wheels also return to the straight traveling position.

In this case, in this embodiment, since the adjusting plates 22 and 23 and the shims 24 and 25 are provided for adjusting the stroke amount,
The variation of the spring constants of the springs 16 and 17 contracted in 4 and 5 and the displacement of the stroke amount due to the assembling accuracy of the piston 3 and the power rod 8 in the horizontal direction in the figure are adjusted by the adjustment plate 2.
It can be adjusted by increasing or decreasing the thickness of the shims 24 and 25.
Therefore, unlike the conventional case, the adjustment plates 22 and 23 and the shim 2
The adjustment range of the thickness of 4, 25 can always be appropriately set for a shift of a predetermined stroke amount. As a result, it is possible to not only adjust the displacement of the initial stroke amount when the rear wheel steering device 1 is assembled, but also appropriately correct the displacement due to the secular change of the stroke amount due to the repetitive action.

Further, the neutral position of the piston 3 is always properly maintained, and the straight running performance of the rear wheel, which is connected to the outside of the power rod 8 and is steered, can be further stabilized, and the steering stability can be improved.

Moreover, the adjustment plates 22, 23 and the shims 24, 25 are attached to the rod covers 6, 7 by attaching the legs of the adjustment plates 22, 23 to the grooves 6a, 7a recessed in the heads 6b, 7b of the rod covers 6, 7. By inserting the 22a and fixing the leg 22a to the rod covers 6 and 7 with the screw 100, it can be easily attached.

Further, in the adjusting plates 52, 53 and the shims 34, 35 shown in FIGS. 9 to 11, without removing the side rods 9, 10 from the power rod 8, the adjusting plates 52, 53 and the shims 34, 35 are connected to the rod covers 6, Since it can be mounted on 7, the assembly man-hour is reduced, and the product cost can be reduced.

<< Effects of the Invention >> As described above, the cylinder device of the rear wheel steering device according to the present invention seals the open end of the cylinder with the rod cover, and houses the piston slidably together with the power rod in the cylinder. A pair of liquid chambers are formed in the cylinder, and the piston is held at a neutral position by an urging force of an urging means provided between the liquid chambers. Stroke adjusting means for adjusting the stroke amount in the left-right direction with the adjusting plate and the number of shims held by the adjusting plate,
By providing between the rod cover and the side rods respectively connected to both ends of the power rod, the adjustment of the stroke amount in the left-right direction from the neutral position of the piston can be performed by the adjustment plate interposed with the shim. The displacement of the stroke amount is appropriately corrected, and the stroke adjusting means can be simplified.

Therefore, the rear wheels are appropriately steered, so that the straight running stability and the steering stability of the vehicle can be improved.

Further, since the stroke adjusting means can be simplified, the cost of assembling the cylinder itself can be reduced, so that the cost of the product can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a cylinder device of the rear wheel steering device according to the present invention, FIG. 2 is a longitudinal sectional view showing a main part of the cylinder device of the rear wheel steering device, and FIG. FIG. 4 is a perspective view showing a main part of a cylinder device of the rear wheel steering device, FIG. 4 is a sectional view of an exploded state showing a main part of the cylinder device of the rear wheel steering device, and FIGS. 5 to 7 are rear wheels of the same. FIG. 8 is a perspective view showing an adjustment plate according to a cylinder device of a steering device, FIG. 8 is a cross-sectional view showing attachment of an adjustment plate according to another embodiment, FIG. 9 is a plan view showing a shim according to another embodiment, FIG. FIG. 11 is a perspective view showing the mounting of an adjustment plate according to another embodiment. 1 ... rear wheel steering device, 2 ... cylinder, 3 ... piston, 22, 23, 32, 33, 42, 43, 52, 53 ... adjustment plate, 24, 2
5,34,35 …… Sim.

Claims (1)

(57) [Scope of request for utility model registration] 1. A cylinder having an open end sealed with a rod cover, a piston slidably housed in the cylinder together with a power rod, and a pair of liquid chambers defined in the cylinder. In a rear wheel steering device for a vehicle in which a piston is held at a neutral position by an urging force of an urging means provided between rooms, a stroke amount in a left-right direction from a neutral position of the piston is held by an adjusting plate and the adjusting plate. A cylinder device for a rear wheel steering device, wherein a stroke adjusting means for adjusting the number of shims is provided between side rods respectively connected to both ends of the power rod and the rod cover.