JPS641180Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a control valve for a power steering device, and more specifically, the present invention includes a first sliding surface that rotates integrally with the first shaft and is perpendicular to the first shaft, and a first sliding surface that rotates integrally with the first shaft and is perpendicular to the first shaft. 1. A first valve rotor having a valve groove opening in a sliding surface, and a second shaft coaxially and rotatably arranged relative to the first shaft rotate integrally with the first valve rotor. a second valve rotor having a second sliding surface in sliding contact with the moving surface and a valve groove opening in the second sliding surface; The present invention relates to a control valve for a power steering device, which is a so-called rotary plate valve type control valve, in which a groove and a valve groove of a second valve rotor overlap and separate to switch a flow path for supplying pressure oil to a power cylinder.

Generally, in this type of control valve, in order to obtain the desired performance, it is necessary to accurately provide each valve groove at a set position, and to form each valve groove's shape accurately, especially the opening shape. In addition, it is desirable to have a structure in which the valve groove can be formed by an inexpensive processing means that is easy to manufacture with high precision and can be manufactured at low cost. By the way, in the past, each of the valve grooves was directly carved on each sliding surface of each of the valve rotors, and it was necessary to accurately provide each valve groove at a set position and to accurately form the opening shape of each valve groove. It is technically very difficult to form and is not suitable for mass production.
In addition, expensive machines such as hobbing machines are used to directly carve each valve groove on each sliding surface with high precision.
The processing for forming each valve groove is expensive due to the above-mentioned technical problems.

The present invention has been developed in view of this situation, and its purpose is to provide a control valve at a low cost, with each valve groove having a structure that can be manufactured at a high productivity and at a low cost.

An embodiment of the present invention will be described below based on the drawings. FIG. 1 shows a control valve 100 for a rack and pinion type power steering system for an automobile according to the present invention, and a housing 10 of the control valve 100 has an inlet port 11 connected to a fixed displacement hydraulic pump 90. , port 12 connected to the left chamber 81 of the power cylinder 80 , right chamber 82 of the power cylinder 80
A port 13 connected to the reservoir 91 and a return port 14 connected to the reservoir 91 are provided. The housing 10 also includes an input shaft 20 and an output shaft 3.
0 are coaxially and relatively rotatably supported.

The input shaft 20 is formed in a hollow shape, is rotatably supported by the housing 10 via a metal bearing 21 at the center, and is connected to the upper end of the output shaft 30 via a needle bearing 22 at its lower end. , the output shaft 3 is connected by the torsion bar 23 inserted inside.
Connected to 0. In addition, torsion bar 23
is connected to the upper end of the input shaft 20 by a pin 24 at its upper end, and to the output shaft 30 by a pin 25 at its lower end. Further, the input shaft 20 has an upper portion that protrudes outside the housing 10 through a seal member 26, and is attached to a steering wheel (not shown).
connected to. Further, a valve rotor A is integrally formed at the lower part of the input shaft 20. The valve rotor A is formed into a disk shape, and its lower surface is a sliding surface Sa perpendicular to the axis. As shown in FIGS. 1 and 2, this sliding surface Sa has eight arcuate valve grooves 20a, 20b, 20c,
20d, 20e, 20f, 20g, and 20h are open in a substantially rectangular shape, and each valve groove 20a to 2
0h are arranged radially at equal intervals in the circumferential direction. In addition, the valve rotor A has four communication holes 20i, 20j, 20 that open to the valve grooves 20b, 20d, 20f, 20h at each lower end and communicate with the return port 14 at each upper end.
k, 20l are drilled in the axial direction.

The output shaft 30 is sealed at the center by a sealing member 31, and has a pair of ball bearings 32, 3.
3 and is rotatably supported by the housing 10. Further, the output shaft 30 has a pinion gear integrally formed on the outer periphery of the lower part, and this pinion gear is connected to a rack gear 34 (which is pushed and pushed by the operation of the power cylinder 80) which is integrally formed with a part of the steering linkage in the housing 10. ). Further, on the upper part of the output shaft 30, there is a rotary rotor that controls communication between the ports 11 to 14 of the housing 10 and switches the flow path for supplying pressure oil to the power cylinder 80 with the valve rotor A of the input shaft 20 described above. A valve rotor B that constitutes the plate valve V is integrally formed. The valve rotor B is formed in a cylindrical shape, and its upper surface serves as a sliding surface Sb that slides on the sliding surface Sa of the valve rotor A of the input shaft. As shown in FIGS. 1 and 3, this sliding surface Sb has eight arcuate valve grooves 3.
0a, 30b, 30c, 30d, 30e, 30
The valve grooves 30a to 30h are arranged radially and at equal intervals in the circumferential direction. Each valve groove 3
0a to 30h are the respective valve grooves of the valve rotor A of the input shaft, as partially shown in FIG. 20a~
20h, and communicate with the adjacent valve grooves 20a to 20h on both sides. In addition, the valve rotor B of the output shaft has a valve groove 3 at each upper end.
Between 0a and 30h, between 30b and 30c, 30d, 3
Four communication holes 30i, 30j, 30k, and 30l are bored at each lower end of the sliding surface Sb between 0e, 30f, and 30g, and communicate with the inlet port ₁₁ through the central annular groove R1. and valve grooves 30b, 30d, 30f, 3 at each upper end.
An annular groove opens at 0h and an upper annular groove at each lower end.
Four communication holes 30m, 30n, 30o, and 30p are bored, each communicating with the port 12 through _R2 . Further, valve grooves 30a, 30 are provided at each upper end.
Four communication holes 30q, 30r, 30s, which open at the ports 13c, 30e, and 30g and communicate with the port 13 through the lower annular groove _R3 at each lower end, respectively.
30t is bored, and valve grooves 30a, 30 are provided at each upper end.
Between b, between 30c and 30d, between 30e and 30f, 3
Four communication holes 30u, 30v, 30w, 30 each open in the sliding surface Sb between 0g and 30h and open in the mounting part of the bearing 32 at each lower end.
x is perforated. In addition, the annular grooves R ₁ , R ₂ , R ₃
are sealed by seal rings 35, 36, 37, and 38.

Therefore, in this embodiment, each valve rotor A, B has a rotor body A ₁ , B ₁ integral with each shaft 20, 30, and a pair of large and small rotor bodies A 1 , B 1 assembled to the rotor body A ₁ , B ₁ . It is composed of ring members A ₂ , A ₃ , B ₂ , and B ₃ . Each rotor body A ₁ , B ₁ has an annular recess a ₁₀ concentric with each shaft 20 , 30 on the inner and outer peripheries of one end surface serving as the respective sliding surfaces Sa and Sb.
a ₂₀ , b ₁₀ , b ₂₀ and both annular recesses in the center
A ₁₀ , a ₂₀ , b ₁₀ , and b ₂₀ have eight radial notch grooves a ₃₀ and b ₃₀ that open at both ends of the inner and outer peripheries, respectively. The ring members A ₂ , A ₃ , B ₂ , B ₃ are fitted and fixed in the respective annular recesses a ₁₀ , a ₂₀ , b ₁₀ , b ₂₀ of the rotor bodies A ₁ , B ₁ , respectively. The end face is each sliding surface
It forms part of Sa and Sb. For this reason, each valve groove 20a to 20h, 30a to 30h is a notch groove.
Both side walls a ₃₁ , a ₃₂ , b ₃₁ , b 32 _of a ₃₀ , b ₃₀ and bottom wall a ₃₃ ,
b ₃₃ and the peripheral wall a ₂ of both ring members A ₂ , A ₃ , B ₂ , B ₃ ,
It is formed by a ₃ , b ₂ , and part of b ₃ .

In the control valve 100 configured as described above, when torque is applied by turning the input shaft 20 clockwise (or counterclockwise) relative to the output shaft 30 when viewed from above in the drawing, the torsion bar 23 twists and the input shaft 20 A relative rotational angular displacement occurs between the output shafts 30, and according to this displacement, each valve groove 20a, 20c, 20e, 20g on the input shaft 20 side opens each communication hole 30i, 30j, 30k, 30l on the output shaft 30 side Each valve groove 20 on the input shaft 20 side communicates with the valve grooves 30a, 30c, 30e, 30g (or each valve groove 30h, 30b, 30d, 30f).
b, 20d, 20f, 20h communicate with each communication hole 30u, 30v, 30w, 30x on the output shaft 30 side and each valve groove 30b, 30d, 30f, 30h (or each valve groove 30a, 30c, 30e, 30g), respectively. and inlet port 11 is port 13 or 1
2 and communicates only with port 12 or 13.
communicates with the return port 14. Therefore,
Pressure oil from the hydraulic pump 90 is supplied to port 13 or 12.
It is supplied to the right chamber 82 (or left chamber 81) of the power cylinder 80 through the flow, and a hydraulic assisting effect is obtained by the operation of the power cylinder 80.

By the way, in this control valve 100, each valve rotor A, B is constituted by a rotor body _A1 , _B1 and a pair of large and small ring members _A2 , _A3 , _B2 , _B3 , and each valve groove 20a~ 20h, 30a to 30h are
Both side walls a ₃₁ , a ₃₂ , _{b 31 ,} b ₃₂ and bottom walls a ₃₃ , b _{33 of} each notch groove a 30 , b 30 and both ring members A ₂ , A ₃ , B ₂ , B ₃
It is formed by a part of the surrounding walls a ₂ , a ₃ , b ₂ , and b ₃ of. Therefore, the manufacturing process of each valve rotor A, B leading to obtaining the above structure involves rotor bodies A ₁ , B ₁
a step of forming both annular recesses a ₁₀ , a ₂₀ , b ₁₀ , b ₂₀ with a lathe or the like, and a step of forming each notch groove a ₃₀ , b ₃₀ in the rotor body A ₁ , B ₁ with a milling machine or the like;
Each annular recess a ₁₀ , a ₂₀ , b ₁₀ in the rotor body A ₁ , B ₁ ,
The process of press-fitting the ring members A ₂ , A ₃ , B ₂ , B ₃ that have been previously plated with zinc or tin plating onto b ₂₀ , and the final process of finishing the sliding surfaces Sa and Sb by grinding (this process was conventionally is also being carried out). Therefore, the annular recesses a ₁₀ , a ₂₀ , b ₁₀ , b ₂₀ and the notched grooves a ₃₀ , b ₃₀ can be machined easily and with high precision, and each valve groove 20a to 20h, 30a to
30h can be accurately provided at a set position, and the opening shape of each valve groove 20a to 20h, 30a to 30h can be formed accurately. In addition, all the steps described above are highly productive and can be carried out at low cost, so each of the valve rotors A and B can be obtained at low cost, and the control valve 100 can be made at low cost. In the above embodiment, the ring members A ₂ , A ₃ , B ₂ , and B ₃ are plated in advance, and when press-fitted, the ring members A ₂ , A ₃ , B ₂ , and B ₃ fit into the annular recesses a ₁₀ , I made sure that it was press-fitted into a ₂₀ , b ₁₀ , and b ₂₀ smoothly (no galling occurred), but
Plating can be applied as necessary.

Further, in the above embodiment, the rotor body A ₁ ,
As shown in FIG. 7, one end surface side of each notch groove A ₃₀ and b ₃₀ in B ₁ can be easily tapered to form a pair of tapered surfaces a ₃₄ and a ₃₅ , When the tapered surfaces a ₃₄ and b ₃₄ are formed in this way, as shown in FIG. Therefore, in the power steering system for an automobile, it is possible to improve both the feeling when driving straight and the return of the steering wheel.

The above explanation is based on one embodiment of the present invention, and the present invention is not limited to the above embodiment. a first valve rotor that rotates integrally and has a first sliding surface orthogonal to the first axis and a valve groove that opens to the first sliding surface;
A second sliding surface that rotates integrally with a second shaft that is disposed coaxially and relatively rotatably with respect to the shaft and makes sliding contact with the first sliding surface, and a valve groove that opens in the second sliding surface. The valve groove of the first valve rotor and the valve groove of the second valve rotor are overlapped and separated by relative rotational angular displacement of the two shafts, and pressure oil is supplied to the power cylinder. It goes without saying that the control valves of various power steering devices that switch the supply flow path can be appropriately modified and implemented, and when implemented, it is also possible to implement it only for one of the valve rotors. It is.

In short, in the present invention, the control valve described above has annular recesses concentric with the shaft on the inner and outer peripheral parts of one end surface serving as the sliding surface, and is sandwiched between the two annular recesses. a rotor body having a notched groove opening in each of the annular recesses in the center thereof, and a pair of large and small rotor bodies that are fitted and fixed in each of the annular recesses of the rotor body, and whose one end surface serves as the sliding surface. The ring member constitutes the valve rotor, and the valve groove is formed by both side walls and the bottom wall of the notched groove and a part of the peripheral wall of both the ring members. Thereby, the structure of the valve groove can be made into a structure that can be manufactured at low cost with good productivity, and the control valve can be provided at low cost.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view showing one embodiment of the present invention, Figs. 2 and 5 are bottom views of the input shaft shown in Fig. 1, and Figs. 3 and 6 are the same as shown in Fig. 1. A top view of the output shaft, Fig. 4 is a partial configuration explanatory diagram of the rotary plate valve shown in Fig. 1, Fig. 7 is a partial side view showing a modification of the ring member, and Fig. 8 is shown in Fig. 7. FIG. 4 is a torque-hydraulic characteristic diagram obtained by a control valve including a ring member. Explanation of symbols, 100...control valve, 10...housing, 20...input shaft, 20a-20h...valve groove, 30...output shaft, 30a-30h...valve groove,
80...Power cylinder, A, B...Valve rotor, _A1 , _B1 ...Rotor body, _a10 , _a20 , _b10 , _b20
... Annular recess, a ₃₀ , b ₃₀ ... Notch groove, a ₃₁ , a ₃₂ ,
b ₃₁ , b ₃₂ ... Both side walls of the notched groove, a ₃₃ , b ₃₃ ... Bottom wall of the notched groove, A ₂ , A ₃ , B ₂ , B ₃ ... Pair of large and small ring members, a ₂ , a ₃ , b ₂ , b ₃ ... peripheral wall of the ring member,
Sa, Sb...Sliding surface.

Claims (1)

[Scope of utility model registration request] A first shaft rotates integrally with the first shaft within the housing.
a first valve rotor having a first sliding surface perpendicular to the shaft and a valve groove opening to the first sliding surface; and a first valve rotor disposed coaxially and rotatably relative to the first shaft. a second valve rotor rotating integrally with the two shafts and having a second sliding surface in sliding contact with the first sliding surface and a valve groove opening in the second sliding surface; A control valve for a power steering device configured to overlap and separate a valve groove of the first valve rotor and a valve groove of the second valve rotor by relative rotational angular displacement to switch a flow path for supplying pressure oil to a power cylinder. The one end surface serving as the sliding surface has an annular recess concentric with the shaft on the inner and outer periphery, respectively, and a central portion sandwiched between the annular recesses and the annular recess. The valve rotor is constituted by a rotor body having a notched groove that opens respectively, and a pair of large and small ring members that are respectively fitted and fixed in the respective annular recesses of the rotor body and whose one end surface becomes the sliding surface, A control valve for a power steering device, wherein the valve groove is formed by both side walls and a bottom wall of the notched groove and a portion of the peripheral walls of both the ring members.