JPS6150828B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved operating valve device for a power steering system, particularly a rotary operating valve device.

This type of operating valve device can simplify the configuration of the operating system, so it is useful as an operating valve device for power steering devices whose mission is to be compact. However, on the other hand, the main components of the operating valve device Since it is difficult to grind the sleeve, especially the outer sleeve, it is difficult to perform high-precision finishing, and the management of tools used for this cutting process is complicated, which has caused many processing problems.

Therefore, the applicant previously proposed a rotary valve most suitable for a power steering device in Japanese Patent Application No. 54-17167 (Japanese Unexamined Patent Publication No. 55-110665) with the aim of solving the above problem.

The rotary valve of the prior application includes an outer sleeve and an inner sleeve that can rotate relative to each other while maintaining sliding contact with each other by twisting a torsion bar corresponding to the steering load. A plurality of recesses spaced apart from each other are formed, and the recesses are alternately connected to a drain chamber facing the pump and one end surface of the outer sleeve, and a groove is formed on the outer peripheral surface of the inner sleeve to communicate between the adjacent recesses. Of these grooves, every other groove is connected to one power cylinder chamber, and the other groove is connected to the other power cylinder chamber.

In this configuration, when the operating valve device is not operating,
Measuring orifices with equal opening areas are set between adjacent recesses of the outer sleeve connected to the pump and drain chambers and both ends of the groove of the inner sleeve that communicates between these recesses, and these metering orifices are A non-operating state is obtained by sequentially releasing hydraulic oil from the depression on the pump side to the depression on the drain chamber side. In the above-mentioned embodiment of the prior application, the recess of the outer sleeve, which has many problems in machining, was solved by making the opening edge into a circular shape that can easily obtain precision, and the opening edge of the recess was also made into a circular shape. In order to obtain good squeezing characteristics of the metering orifice due to the relative rotation of the inner and outer sleeves, the groove provided on the outer periphery of the inner sleeve, which is relatively easy to process, has a claw-shaped bottom surface. By the way, if the opening area of the metering orifice is small, it will not be possible to release all the hydraulic oil from the pump, resulting in a large pressure loss. However, in the rotary valve of the embodiment of the prior application, since the opening edge of the recess formed on the inner peripheral surface of the outer sleeve is circular, the recess can be formed easily and inexpensively by drilling holes, but the pressure loss is reduced. Therefore, in order to increase the opening area of the metering orifice, it is necessary to increase the circular opening edge of the recess. However, when the diameter of this circular opening edge is increased, the inner circumferential surface portion of the outer sleeve in which the recess is not formed between adjacent opening edges becomes shorter and smaller in the circumferential direction, resulting in a decrease in the strength of the outer sleeve. Therefore, in the rotary valve of the embodiment of the prior application, in order to avoid this decrease in strength, the diameter of the outer sleeve must be increased, and the operating valve device cannot avoid increasing in size.

The present invention forms diagonal holes in the outer sleeve extending from the end surface of the outer sleeve adjacent to the drain chamber to the inner circumferential surface of the outer sleeve, and by forming the recesses with these diagonal holes, the opening edges of these recesses are By making the outer sleeve into an elliptical shape long in the axial direction and closing the opening end on the drain chamber side of the diagonal hole constituting the recess to be connected to the pump, the outer sleeve can be formed without a recess while maintaining the ease of machining the recess. The opening area of the metering orifice can be made relatively large without shortening the circumferential portion of the inner circumferential surface and without reducing the strength of the outer sleeve, thereby creating a rotary valve that is small and has low pressure loss. This paper proposes a technical idea for improving the operating valve device of a power steering device by embodying this idea.

Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments, and its effects will be mentioned.

1 to 4 show an operating valve device for a power steering system according to the present invention. In the figures, 1 is a valve box, and a rack guide 2 is integrally provided at one end of the valve box, and the opening at the other end is connected to an end cover 3. occlusion. A rack 4 is guided in its longitudinal direction by a rack guide 2, and knuckle arms on corresponding sides are connected to both ends of the rack 4, so that both steering wheels can be steered. Rack 4 has Rack teeth 4
A and a power piston 5 as shown in the third figure. The power piston 5 is slidably fitted into the power cylinder 6.
Power cylinder chambers 7 and 8 are defined on both sides of the cylinder, and connectors 9 and 10 are connected to these chambers, respectively. When hydraulic pressure is supplied to the left chamber 7 of the power cylinder chambers 7 and 8, the rack 4 is power assisted to the right in FIG. 3, both steering wheels are steered to the left, and when hydraulic pressure is supplied to the right chamber 8. , the rack 4 is power assisted to the left in FIG. 3, and both steering wheels can be steered to the right.

As shown in FIGS. 1 and 3, the rack teeth 4a
, the pinion 11 provided on the pinion shaft 11
a, and pinion shaft 11 is engaged with bearing 1.
2 and 13, it is rotatably supported. pinion 1
The side of the rack 4 opposite to 1a is supported by a column 14, as shown in FIG. 3, and this column is biased toward the rack 4 by a spring 15. A pinion shaft 11 protrudes into the valve body 1 under liquid-tight sealing by a seal 16.
A stub shaft 17 is provided coaxially and oppositely at the end of the stub shaft 17, and the opposing ends of both shafts are made relatively rotatable by a bearing 18, and the other end of the stub shaft 17 is supported by the end cover 3 via a bearing 19. The end cover 3 is penetrated under liquid sealing by the seal 20. Incidentally, a serration 17a is formed at the end of the stub shaft 17 that penetrates the end cover 3 and projects from the valve box 1, and a steering wheel (not shown) and a steering shaft that can be rotated integrally can be connected via this serration. do.

The stub shaft 17 is made hollow, and the torsion bar 21 is inserted into this hollow hole.
One end of the pinion shaft 11 is fitted into a blind hole 11b formed in the end face of the pinion shaft 11 and integrally connected to the pinion shaft 11 in the rotational and axial direction by a pin 22, and the other end is connected to the stub shaft 17 by a pin 23. Join together in the direction.

An inner sleeve 24 is integrally molded on the stub shaft 17, and this inner sleeve is disposed within the valve body 1. The outer sleeve 25 is fitted to the outer circumferential surface of the inner sleeve 24 in a slidable manner so as to be relatively rotatable, and the outer circumferential surface of the outer sleeve 25 is fitted in the valve body 1 in a slidable and rotatable manner. As shown in FIGS. 1 and 2, the outer sleeve 25 has, for example, four holes spaced apart from each other in the circumferential direction.
Diagonal holes 25a, 25b, 25c, and 25d are drilled to form recesses 28, 29, 30, and 31 in the inner peripheral surface of the outer sleeve 25 that are spaced apart from each other in the circumferential direction and open toward the inner sleeve 24. Form. As clearly shown in FIG. 1, these oblique holes 25a to 25d are inclined so as to reach the inner circumferential surface of the outer sleeve from the end surface of the outer sleeve 25 facing the chamber 39 which becomes a drain chamber as described later. The opening edges of the recesses 28 to 31 on the inner circumferential surface of the outer sleeve are shaped like ellipses that are elongated in the axial direction of the outer sleeve (the left-right direction in FIG. 1). Note that three grooves 26a, 26b, and 26c are formed on the outer circumferential surface of the outer sleeve 25, and as shown in FIG. position.

As clearly shown in FIG. 2, grooves 24a, 24b, 24c, and 24d are formed on the outer peripheral surface of the inner sleeve 24 to communicate adjacent ones of the depressions 28 to 31.
is formed as shown in FIG. These grooves 24a, 2
4b, 24c, and 24d refer to the groove 24a, for example, as shown in FIG. It can be easily formed by rotating it around an axis 60 that is parallel to the axis and moving it in a direction perpendicular to the axis of the inner sleeve. Note that the groove 24
The width of a, 24b, 24c, 24d is the depression 28-3
It is preferable that the length be smaller than the major axis of the above-mentioned oval opening edge in No. 1.

The outer sleeve 25 is further provided with holes 33 to 36 passing through it in the radial direction.
In the inner peripheral surface of the outer sleeve 25, there are grooves 24, respectively.
a, 24b, 24c, and 24d, the other end openings of the holes 33, 34 are common to the groove 26c, and the other end openings of the holes 35, 36 are the groove 26b.
are commonly communicated with each other. The outer sleeve 25 is further provided with through holes 37 and 38, which allow the recesses 28 and 29 to communicate with the groove 26a, respectively, and the recesses 30 and 31 are formed by diagonal holes 25c and 25d, respectively.
It communicates with a drain chamber 39 defined between the end cap 3 and the outer sleeve 25. As shown in FIG. 1, the open ends of the diagonal holes 25a, 25b, which are connected to the depressions 28, 29 communicated with the groove 26a by the through holes 37, 38, close to the drain chamber 39 are closed by the plug 27. As shown in FIGS. 1 and 2, the outer sleeve 25 has a diagonal hole 2 formed by recesses 30 and 31.
Lubrication hole 25 extending in the opposite direction to 5c and 25d
e and 25f are formed so that hydraulic oil used for lubricating the bearing 13 and the seal 16 can be supplied through these holes.

As clearly shown in FIGS. 3 and 4, the pinion shaft 11 is integrally provided with protrusions 11c that protrude radially outward at the end close to the inner sleeve 24, and these protrusions are connected to the fan-shaped notches 24f of the inner sleeve 24. A pin 40 is placed on the outer circumferential surface of the protrusion 11c so as to be engageable therein. The fan-shaped notch 24g is made slightly larger than the width of the protrusion 11c, so that these protrusions, and therefore the pinion shaft 11, are connected to the inner sleeve 2.
4 within a permissible range, that is, within a range until the side surface of the protrusion 11c collides with the wall of the fan-shaped notch 24f. Further, the pin 40 is tightly engaged with a notch 25h formed in the outer sleeve 25, and thereby the outer sleeve 25 is connected to the pinion shaft 11.
It can be rotated integrally with the

The valve box 1 has an inlet boat 41 opening into the groove 26a as shown in FIG. 1, a drain port 42 communicating with the drain chamber 39, and an inlet port 42 communicating with the grooves 26b and 26c as shown in FIG. Communication port 43,4
4. The inflation port 41 is connected to the oil pump, the drain port 42 is connected to the oil reservoir, and the communication ports 43 and 44 are connected to the power cylinder chambers 7 and 8 via conduits 45 and 46 and connectors 9 and 10, respectively. .

The operation of the operating valve device of the present invention having the above-mentioned structure will be explained next.

1 to 4 show the state in which the operating valve device of the present invention is in a neutral state. In this state, as is clear from FIG.
Both ends are equally open to the corresponding depressions 28 to 31, and the hydraulic oil supplied from the pump to the depressions 28 and 29 via the inlet boat 41, the groove 26a, and the through holes 37 and 38 is supplied to the depressions 28 and 29 through the grooves and depressions. 30,3
1. Furthermore, the diagonal holes 25c and 25d, and the drain chamber 39
and is extracted through the drain port 42, and the depression 2
8 and 29 do not generate oil pressure. At the same time, the power cylinder chambers 7 and 8 shown in FIG.
Communication ports 43, 44, grooves 26b, 26c, holes 33, 34, 35, 36, grooves 24a, 24b, 2
4c and 24d to the drain recesses 30 and 31, and no hydraulic movement force is generated in the rack 4.

Here, when the steering wheel is rotated and the steering operation is performed, if the steering load is small, the torsion bar 21 is not twisted, and the pinion shaft 11 is rotated integrally with the stub shaft 17 via this torsion bar, and the operating valve device is rotated. The steering wheel is steered without power assistance by moving the rack 4 in the longitudinal direction while maintaining the above-mentioned neutral state.

However, when the steering load is large during steering operation, the pinion shaft 11 does not rotate following the stub shaft 17, and the torsion bar 21 is twisted in the steering direction according to the steering load, causing the pinion shaft 11 to rotate integrally with the pinion shaft 11. The sleeve 25 and the inner sleeve integrated with the stub shaft 17 rotate relative to each other in the steering direction by an angle corresponding to the steering load (torsion angle of the torsion bar 21), and the actuated valve device of the present invention has the following effect during steering operation. Provides power assist.

That is, when steering to the left, the inner sleeve 24 rotates relative to the outer sleeve 25 in the direction shown by the arrow in FIG. 7, for example to the position shown in this figure.
At this time, the degree of communication between the grooves 24a, 24b, 24c, and 24d with the recesses 28, 29, 30, and 31 on the delayed side of the rotational direction of the inner sleeve 24 is reduced, and the degree of communication between the grooves 24a, 24b, 24c, and 24d is reduced, and the recesses 30, Increase the degree of communication with 29, 31, and 28. As a result, hydraulic pressure is generated in the depressions 28 and 29, which have a reduced degree of communication with the depressions 30 and 31, and the holes 33 and 34 communicating with the power cylinder chamber 8 on the right side (see FIG. 3) are drained as described above. Recesses 30, 31
It is very similar to The hydraulic pressure generated in the depressions 28 and 29 is applied to the grooves 24d and 24b, the holes 36 and 35, and the groove 26.
b. It is supplied to the left power cylinder chamber 7 through the communication port 43 and the conduit 45, and power assists the rack 4 in the right direction in FIG. 3 to help steer the steering wheels to the left.

Further, when the steering operation is performed to the right, the inner sleeve 24 is rotated in the opposite direction to the above-described direction relative to the outer sleeve 25, and at this time, hydraulic pressure is similarly generated in the recesses 28 and 29. However, in this case, the depressions 28,2
9 is supplied to the power cylinder chamber 8 on the right side through the grooves 24a, 24c and holes 33, 34, and the power cylinder chamber 7 on the left side communicates with the drain recesses 30, 31 through the holes 35, 36. , the rack 4 is power-assisted toward the left in FIG. 3, and power steering is possible when steering to the right.

Then, when the hydraulic oil flow from the pump disappears and power steering becomes impossible, during the relative rotation between the inner sleeve 24 and the outer sleeve 25, the wall of the fan-shaped notch 24f shown in FIG. collide with. Therefore, the rotational force input to the inner sleeve 24, which is integrated with the stub shaft 17, is mechanically transmitted to the pinion shaft 11 via the protrusion 11c, and when the power steering device malfunctions, manual steering is performed, and the steering This can prevent it from becoming unremovable.

Thus, in the power steering device of the present invention, since the opening edges of the recesses 28 to 31 are formed into an elliptical shape elongated in the axial direction of the outer sleeve 25 as described above, the outer sleeve 25 does not have the recess formed between these opening edges. Both ends of the outer sleeve in the circumferential direction of the recesses 28 to 31 and the groove 24 can be
The opening area of the metering orifice formed by both ends of a, 24b, 24c, and 24d can be increased,
Therefore, the strength of the outer sleeve 25 is not decreased, and in order to avoid this decrease in strength, the outer sleeve 25 is
The pressure loss problem can be solved without increasing the diameter of the operating valve device and increasing the size of the operating valve device.

Moreover, in making the opening edges of the recesses 28 to 31 long in the axial direction of the outer sleeve 25, the outer sleeve 25 is tilted so as to reach the inner peripheral surface of the outer sleeve from the end surface of the outer sleeve 25 facing the drain chamber 39. Hole 2
5a to 25d, the above-mentioned depressions can be formed by a very common drilling process, and the advantages regarding the workability and precision of the depressions in the rotary valve of the earlier application are inherited as they are. The above effects can be achieved without compromising this advantage.

[Brief explanation of the drawing]

Figure 1 shows the actuating valve device of the present invention at A ₁ -O in Figure 2.
-A ₂ -A ₃ -A A sectional view taken along the line ₄ and viewed in the direction of the arrow; Figure 2 is a cross-sectional view of B ₁ - _{B 2} in Figure 1; Figure 3 is a cross-sectional view of C ₁ - C in Figure 2. ₂ ―C ₃ ―C ₄ ―C ₅ Cross-sectional view on line,
Figure 4 is a sectional view of _D1 - _D2 in Figure 1, and Figure 5 is a cross-sectional view of Figure 1.
Fig. 6 is a perspective view of the inner sleeve used in the device of the present invention shown in Figs. FIG. 2 is a sectional view similar to FIG. 2 used to explain the operation of the inventive device. 1... Valve box, 2... Rack guide, 3... End cover, 4...
Rack, 5... Power piston, 6... Power cylinder, 7, 8... Power cylinder chamber, 11... Pinion shaft, 17... Stub shaft, 21... Torsion bar, 22, 23... Pin, 24... Inner sleeve, 24a, 24b, 24c , 24d...groove, 25
...Outer sleeve, 25a, 25b, 25c, 25d
... Oblique hole, 27 ... Plug, 28-31 ... Hollow, 33
~36...hole, 37,38...through hole, 39...drain chamber, 40...pin, 41...inlet port, 42
...Drain port, 43, 44...Communication port, 4
5,46...Pipeline.

Claims (1)

[Claims] 1.Equipped with an outer sleeve and an inner sleeve that can rotate relative to each other while maintaining sliding contact with each other by twisting a torsion bar corresponding to the steering load, and a plurality of sleeves spaced apart from each other in the circumferential direction are provided on the inner circumferential surface of the outer sleeve. In addition to forming depressions, these depressions are alternately connected to the drain chamber facing the pump and one end surface of the outer sleeve, grooves are provided on the outer peripheral surface of the inner sleeve to communicate between the adjacent depressions, and among these grooves, In a power steering device in which every other groove is connected to one power cylinder chamber and the other groove is connected to the other power cylinder chamber, the outer sleeve is connected from the end surface of the outer sleeve facing the drain chamber. Diagonal holes extending to the inner peripheral surface are formed in the outer sleeve, and by forming the recesses with these diagonal holes, the opening edges of these recesses on the inner peripheral surface of the outer sleeve are shaped like ellipses that are elongated in the axial direction of the outer sleeve. An operating valve device for a power steering device, characterized in that an opening end on the drain chamber side of the oblique hole constituting a recess to be connected to a pump is closed.