JPS62151245A - Production of rotary valve - Google Patents

Abstract

PURPOSE:To easily form passage grooves having a desired shape with high accuracy in the stage of forming a rotor stock by a lost wax method by forming the passage grooves in the outside peripheral part of a rotor to a deep groove shape then finishing the width of the respective passage grooves. CONSTITUTION:A rotary valve is recessed with the plural passage grooves which are selectively communicated and shut off by relative turning displacements in the outside peripheral part of the rotor 15 and the inside peripheral part of a sleeve 16 at prescribed intervals in the peripheral direction. The passage grooves 30 in the outside peripheral part of the rotor 15 are formed to the deep groove shape in the stage of forming the stock 31 thereof by the lost wax method. The width of the grooves 30 is then finished to form the grooves 15a having the prescribed groove width. The sleeve 16 is similarly formed with the passage grooves 30 in the inside peripheral part of the stock and the grooves are finished to the grooves 16a having the prescribed width. The passage grooves of the rotor or sleeve are thereby easily formed to the desired shape with the high accuracy.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rotary valve used as a control valve for distributing and controlling pressure fluid in a power steering system for reducing steering force of an automobile, and in particular to The present invention relates to an improvement in a method for manufacturing a rotor or sleeve having a plurality of passage grooves selectively connected by rotational displacement.

[Conventional technology]

A power steering device, which is generally well known as a power steering device, is powered by an oil pump that serves as a hydraulic pressure generation source that supplies hydraulic oil as a pressurized fluid from an oil tank to the power steering body. A control valve that distributes and controls the supplied pressure oil in accordance with handle operation, and the pressure oil is located on the left side of the control valve.
The left by being flowed into one liquid chamber side on the right.

It consists of a power cylinder or the like equipped with a piston that is selectively moved in the right direction, and is configured to transmit the movement of the piston of the power cylinder in the direction of supply of pressure oil to the steering link mechanism to assist its steering movement. ing. and,
In this type of power steering device, a rotary type consisting of a rotor and a sleeve is used as a control valve for switching the flow path to selectively switch the hydraulic circuit to the power cylinder using rotational movement by steering wheel operation. have been commonly used for a long time.

The schematic structure of the rotary valve 10 used as a flow path switching control valve in such a power steering device will be briefly explained using FIG. A pinion shaft 12 on the output side having a meshing pinion lla is coaxially connected to the right end side of the pinion shaft 11 via a torsion 8-13, and an input shaft whose right end is connected to the steering wheel side (not shown). So, these two axes 11. L2 is rotated as appropriate in the steering direction. 14 are these two axes 1
1 and 12 are arranged through the rotary valve 10, and the relative rotational displacement thereof is used as manual power to switch the flow paths between the oil pump P, the oil tank T, and the power cylinder left and right cylinder chambers CL and CR. The valve housing 14 rotatably accommodates and supports a rotor 15 and a sleeve 16, which are integrally provided to the shafts 12 and 11, respectively. These rotors 1
5, the sleeve 16, and the housing 14 are well known, and the outer circumferential surface of the rotor 15 and the inner circumferential surface of the sleeve 16, which face and slide against each other, each have a plurality of hydraulic circuits arranged at predetermined intervals in the circumferential direction. passage groove 15a
, 16a are recessed, and a plurality of passage holes 17a, 17b; 18a, 18b, 18c, taci
are formed by drilling at appropriate locations, and these passage grooves 15a
, 16a, etc., the hydraulic circuit described above is switched and controlled as necessary. Here, 19.20 in Figure 1 is a suction boat into which pressure oil flows from the oil pump P and a return boat which returns the pressure oil to the oil tank T, and 21A and 21B are the left and right cylinder chambers CL and CR of the power cylinder. 22a, 22b, 22c, and 22d are annular grooves formed on the outer periphery of the sleeve 16 and communicated with the boats, and 23a, 23b, and 23C are for rotating each part. The freely supporting bearings 24a and 24b are oil seals.

The configuration and operation of the rotary valve 10 as a flow path switching control valve having such a configuration are conventionally well known, and detailed explanation thereof will be omitted.

[Problem that the invention seeks to solve]

By the way, in the rotary valve IO as described above, the rotor 15 and the sleeve 16 as its components
The passage groove 15a is formed in the passage groove 15a.

Conventionally, the passage grooves 16a are generally formed by cutting with a cutting machining tool using a cutter or the like, and as a result, these passage grooves 15a and 16a are formed along their longitudinal direction, as is clear from FIG. The groove bottom is shaped like an arc and has a limited cross-sectional shape, and the depth of the groove becomes shallower at both end portions due to the curved surface. And on the other hand,
At both end portions of such passages IJ15a, 16a, there are left and right cylinder chambers CL of the power cylinder bored on the sleeve 16 side, as shown by imaginary lines in FIG.
The passage holes 18b and 18C connected to the CR are opened due to necessity in their configuration, and as a result, the wave cross-sectional area at the passage connection portion described above is narrowed, causing pressure fluctuations and pressure fluctuations in the flow of pressure oil. Turbulence and the like occur, resulting in a large pressure loss in this part, which causes problems such as a large energy loss in the entire hydraulic circuit system and the generation of abnormal noise.

Therefore, according to the machining using the cutting tool as described above, the passage grooves 15a of the rotor 15 and the sleeve 16 are
, 16a is nearly impossible to secure the necessary groove depth at both ends of the grooves, and it is imperative that some measure be taken to eliminate the above-mentioned problems, such as by using a simpler molding method.

Furthermore, the input shaft 12 constituting the rotor 15 described above is formed in a complicated shape, including a protrusion (see the left end in FIG. 2) that serves as a means for securing the output side (11). However, the molding process is troublesome and complicated, and the passage groove 16a is also formed on the inner circumferential surface of the sleeve 16.

Special tools are required, and the complexity of the molding process is unavoidable, so it is desirable to take these points into consideration.

[Means for solving problems]

In order to meet such demands, the rotary valve manufacturing method according to the present invention includes a plurality of passage grooves that are selectively communicated and cut off by relative rotational displacement on the outer circumference of the rotor and the inner circumference of the sleeve. In a rotary valve formed at predetermined intervals in the direction, the passage grooves are formed into a deep groove shape when forming the rotor material or the sleeve material by the lost wax method, and then the groove width of each of these passage grooves is finished. Accordingly, the groove width is formed to a predetermined width.

[Effect]

According to the present invention, by using the lost wax method,
In addition to forming a passage groove with the necessary groove depth by simply and appropriately recessing it, the groove width can be adjusted and adjusted to form the required groove width with high accuracy, making it possible to It becomes possible to form passage grooves that can eliminate problems such as pressure loss.

〔Example〕

Hereinafter, one embodiment of the present invention will be explained in detail using an embodiment shown in the drawings.

FIGS. 1(a), (b) to 3 show a method of manufacturing a rotary valve according to the present invention, which is one of the components of a rotary type control valve for switching flow paths in a power steering device. This figure shows the case where the present invention is applied to the rotor 15, and in these figures, the same or corresponding parts as in FIG.

Now, according to the present invention, a plurality of passage grooves 15a, 16a are selectively communicated with and interrupted by relative rotational displacement between the outer circumference of the rotor 15 and the inner circumference of the sleeve 16 (see FIG. 6).
In the rotary valve 10, in which rotor blanks 31 are formed at predetermined intervals in the circumferential direction, passages on the outer periphery of the rotor 15 are formed as shown in FIGS. 2(a) and 2(b). The groove 30 (15a) is formed into a deep groove shape, and then the groove width of each passage groove 15a is determined as follows.
The groove width is formed to a predetermined width dimension by machining the grinding tool 32 as shown in FIG. 3.

That is, the passage groove 30 recessed in the rotor material 31 by the above-mentioned lost wax method is formed to be slightly narrower than the required groove width of the passage groove 15a, and this is adjusted by grinding A32hJ-. The structure is such that the groove width is finished with a certain degree of precision, thereby making it possible to form the passage groove 15a with excellent precision. Here, - the finishing method of the passage groove 30 described above is not limited to the case of using the grinding tool 32 described in h, for example, a cutting tool may be used, or plastic working such as forging or rolling may be employed. You may do as you please.

Then, the passage groove 30 (15a
) can be easily and reliably formed by using the lost wax method in a shape that is substantially uniform throughout the longitudinal direction and has a groove depth of the required depth, As a result, the passage holes 18b, 18 as in the conventional
This can eliminate problems such as pressure loss caused by processing c, and its practical effects are great.

Therefore, according to the passage groove 30 (15a) formed using the above-mentioned lost wax method, the groove depth, that is, the cross-sectional area of the passage, can be particularly improved compared to the conventional machining process such as cutting. It is possible to increase the depth of the groove at both ends, and as a result, it is possible to prevent pressure loss from decreasing due to the flow of pressure fluid, thereby saving energy and reducing noise in hydraulic circuit systems. It also has the advantage of being able to prevent the pressure oil from rising in temperature by 1F.

Here, in this embodiment, the passage groove 30 (15a) described above is
This figure shows a case in which, when the tank is formed by the lost wax method, the passage holes 17a for returning to the tank side, which are formed in communication with some of the passage grooves 30, are also integrally formed by the lost wax method. As a result, the pressure oil passage can be appropriately sized and the pressure oil can flow smoothly and appropriately in the hydraulic circuit. Furthermore, if the entire human power shaft 12 having a complicated shape including the rotor 15 integrated with the input shaft 12 in the power steering device is formed by the lost wax method as in this embodiment, the input shaft 1
There is also an advantage that the molding processability of the whole 2 is greatly improved.

Note that the present invention is not limited to the structure of the embodiment described above, and the shape, structure, etc. of each part may be modified or changed as appropriate. For example, in the above-mentioned embodiment, a case has been described in which the present invention is applied to the passage groove 15a of the rotor 15 in the rotary valve IO, but the present invention is not limited to this, and as shown in FIGS. 4(a) and (b). It is easy to understand that it may be applied to the passage groove 16a side of the sleeve 16 having the above-mentioned shape, and the same effect as described above can be achieved.In this case, the passage groove 30 (16a ), as shown in FIG. 5, if a configuration is adopted in which one end thereof is formed in communication with one end surface of the sleeve 16, and a collar 33 is press-fitted so as to close the outer end, It is easy to adopt the lost wax method.

Furthermore, the method for manufacturing the rotary valve IO according to the present invention includes:
The present invention is not limited to control valves in power steering devices as described above, but can be applied to rotary valves in various fields to exhibit its effects.

〔Effect of the invention〕

As explained above, according to the method for manufacturing a rotary valve according to the present invention, a plurality of passage grooves that are selectively communicated with and cut off by relative rotational displacement on the outer circumference of the rotor and the inner circumference of the sleeve are formed in the circumferential direction. In a rotary valve formed at predetermined intervals, the passage grooves are formed in a deep groove shape when forming the rotor material or the sleeve material by a lost wax method, and then the groove width of each passage groove is finished. Although it is a simple and inexpensive method, by using the lost wax method, the passage groove with the required groove depth can be easily and appropriately recessed. In addition, it is possible to form passage grooves that can be precisely formed with the necessary groove width by finishing with a grinding tool, etc., and eliminate problems such as pressure loss, etc., which were conventional. It has various excellent effects.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) are main part sectional views showing an embodiment in which the rotary valve manufacturing method according to the present invention is applied to a rotor in a control valve for a power steering device, and FIG. 2(a) and (b) are main part sectional views showing the state of the rotor material and its II-n
A line sectional view, FIG. 3 is an enlarged sectional view of the main part showing the finishing process, and FIGS. 4(a) and (b) are main parts of the sleeve manufactured by applying the rotary valve manufacturing method according to the present invention. A partial cross-sectional view and a cross-sectional view taken along the line IV-IT, FIG. 5 is a cross-sectional view of a main part showing a modification thereof, and FIG. 6 is a schematic configuration of a flow path switching control valve portion in a power steering device to which the present invention is applied. FIG. 1Oe11+1・Rotary valve (flow path switching control valve), 11・Fights・Output side pinion shaft, 12
・0・ψ input shaft, 15... rotor l 511 *
+1 @Sleeve, 15a, 16a* *-・Passway groove, 17a, 17b; 18a, 18b. 18c, 18d... Passage hole, 3o, fist, passage groove by lost wax method, 31, fist, 3 - evening material, 3
2... Grinding tool, P... Oil pump, T...
φ・Oil tank, CL, CR...φ left and right cylinder chambers. Patent applicant: Automotive Equipment Co., Ltd. Agent: Masatsuna Yamakawa (and 2 others) Figure 3 jU Figure 4 (a) Figure 4 (b) 6C

Claims (2)

[Claims] (1) In a rotary valve in which a plurality of passage grooves are formed at predetermined intervals in the circumferential direction, the passage grooves are formed at predetermined intervals in the circumferential direction and are selectively communicated with and shut off by relative rotational displacement on the outer circumference of the rotor and the inner circumference of the sleeve. When forming the rotor by a lost wax method, the passage grooves on the outer circumference of the rotor are formed in a deep groove shape, and then the groove width of each of these passage grooves is finished to a predetermined width. A method for manufacturing rotary valves. (2) In a rotary valve in which a plurality of passage grooves are formed at predetermined intervals in the circumferential direction and are selectively communicated with and shut off by relative rotational displacement on the outer circumference of the rotor and the inner circumference of the sleeve, the sleeve material is When forming the sleeve by the lost wax method, the passage grooves on the inner circumference of the sleeve are formed into deep groove shapes, and then the groove widths of these passage grooves are finished to a predetermined width. A method of manufacturing a rotary valve.