JPS59120333A - Chamfering method of valve rotor for hydraulic rotary valve - Google Patents

Abstract

PURPOSE:To form a chamfered part efficiently and to produce a hydraulic rotary valve having an excellent hydraulic characteristic in the stage of chamfering the end edges of both walls in the groove of the valve rotor of the hydraulic rotary valve by pressing and rolling said edges with a pair of specifically constructed rolling tools. CONSTITUTION:A hydraulic rotary valve for a power steering device, etc. is constituted of a valve rotor which is formed with axial grooves and a valve sleeve which is fitted freely rotatably onto said rotor and has internally axial grooves superposing on both circumferential sides of the grooves formed on the valve rotor. Chamfered parts of a prescribed shape are formed at the end edges 6 of both walls of the grooves 2 provided to the valve rotor in order to obtain an optimum steering power characteristic. A pair of rolling tools 3, 4 are disposed on both sides of the valve rotor 1 having plural grooves 2 for the above-mentioned purpose. The rolling tools have bulging parts 5, 5 which project in a diametral direction at the space roughly equal to the width W of the groove 2 provided to the rotor 1 and extend in the axial direction. Chamfered parts 7 are easily formed in the grooves 2 of the valve rotor by rotating such rolling tools 3, 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic rotary valve used, for example, in a power steering device, and more particularly to a method for forming chamfered portions on both wall edges of a groove in a valve rotor.

Hydraulic rotary valves used in power steering devices, etc. have a valve rotor with a plurality of axial grooves formed therein, and are rotatably fitted around the outer periphery of this Buna rotor. The valve sleeve has an axial groove that can be overlapped with the valve rotor, and the supply and discharge of pressurized fluid to and from the power cylinder is controlled in accordance with the relative rotational displacement between the valve rotor and the Buna sleeve. Since the hydraulic characteristics of the rotary valve are determined by the shape of the portion where the grooves of both the valve rotor and the valve sleeve overlap, in order to obtain the optimum steering force characteristics, both walls of the groove of the valve rotor are 2. Description of the Related Art Hydraulic rotary valves having chamfered portions of a predetermined shape formed on their edges are conventionally known.

Various methods have been used to form the chamfered portions of the grooves of the valve rotor, and the most common method is to perform grinding using a surface grinder.
According to this method, each groove must be ground sequentially, which increases the machining time, and it is also impossible to perform curved chamfering, so it is not suitable. It was difficult to obtain steering force characteristics. For this purpose, a method has been proposed in which a chamfer is formed by plastically deforming the groove by pressing a tool into the groove, without using methods such as grinding or cutting (Japanese Patent Publication No. 52-4807).

JP-A-53-95182, etc.). However, no matter which glue method is used, the same number of grooves as the grooves formed in the valve rotor
- It is necessary to use a single tool or to perform the process multiple times with a single tool, and the need for multiple tools is undesirable due to the high cost, and it is also necessary to form through multiple F culms. had the disadvantage that the production efficiency was -1-unfavorable.

The present invention has been made in view of the following point -1-, in which a pair of bulges extending in the axial direction are spaced apart from each other at an interval substantially equal to the width of the valley grooves of the valve rotor, and the bulges are arranged at intervals equal to the interval between the respective grooves. Using a plurality of pairs of rolling tools, the axes of both the rolling tool and the valve rotor are arranged in a V-line, and the pair of bulges and the grooves of the valve rotor are arranged in correspondence with each other. By rolling this rolling while pressing A, it is possible to efficiently form a chamfered part using a device with a simple configuration.Moreover, this chamfered part can be formed into a desired shape and a hydraulic rotation with good hydraulic characteristics can be used. The present invention provides a method for chamfering a valve rotor to obtain a valve.

Hereinafter, the present invention will be explained based on illustrated embodiments. FIG. 1 is a simplified explanatory view showing the process of chamfering the vortex of the valve rotor by the method of the present invention, and the center of the figure is the axis of the valve rotor (1) before the chamfer is formed. A cross section perpendicular to is shown. This valve rotor (1) is conventionally known,
Although the details are not shown, an even number of axial grooves (2) such as 4, 6, or 8 grooves are formed at equal intervals on the outer circumferential surface of the valve rotor (1). A hydraulic rotary valve is formed together with a valve sleeve which rotates at the same time (a plurality of axial grooves are fitted over the circumferential sides of the groove (2)). Even if the grooves (2) of the five-valve rotor (1) are not equally spaced, if the grooves of the valve sleeve are formed to correspond to these grooves (2), a rotating valve can be constructed. .

A pair of rolling lower JLs (3) and (4) are arranged on both sides of the valve rotor (1) with their axes parallel to the axis of the rotor (1). ), (4) have bulges () that form a pair with an interval substantially equal to the width (W) of the groove (2) of the valve rotor (1), protrude in the radial direction, and extend in the axial direction.
5) and (5) are formed. In addition, these bulges (5
) and (5) are provided on the entire outer periphery of the tools (3) and (4) at intervals equal to the circumferential distance MCL) of the valley groove (2) of the valve rotor (1). Therefore, the tool (
3) A rain reduction tool (3) in which the pair of bulges (5), (5) of (4) correspond to one of the grooves (2) of the valve rotor (1).
, (4), the name groove (2) and each pair of bulges (
5).

(5) always rotate in correspondence with each other.

An even number of axial grooves (2) are carved around the entire circumference of the valve rotor (1).
), at a position where the bulges (5) of the rolling tools (3) and (4) of the above configuration correspond to the grooves (2) of the valve rotor (1), Both 1゛ ingredients (3).

(4), the valve rotor (1) is compressed from both sides, and in this state 7ffi, the valve rotor (1) is compressed from both sides. Roll (3) and (4).

As a result, both wall edges (6) of the groove (2) are cut by the tool (3), (
Pressed by the bulge (5) of 4), the bulge (5)
A recessed chamfered portion (7) (see FIG. 2) having the same outline and shape is formed. Since the chamfered part is formed by rolling in this way, it takes 10 hours to process the valve rotor (
1) The efficiency of manufacturing can be improved.

In addition, since the valve rotor (1) and the shafts of the valve rotors (3) and (4) are arranged and rotated in parallel, the chamfered portion (7) can be finished with high precision. In order to achieve this, it is only necessary to perform continuous rotation, which is extremely efficient compared to conventional methods. Moreover, the shape of the chamfered portion (7) is different from that obtained by grinding or other means.
By appropriately setting the contour of the bulging portion (5), it can be made into any shape such as a curved shape, so it is easy to improve the hydraulic characteristics of the rotary valve and make it optimal. be.

As described above, according to the method of the present invention, the chamfering of the valve rotor can be extremely efficiently pressurized, and furthermore, an arbitrary shape can be easily obtained, so that the hydraulic characteristics can be improved. be able to.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of the method of the present invention, and FIG. 2 is a sectional view showing an example of a chamfered portion pressurized by the method of the present invention. (1)...Valve rotor, (2)...Groove of valve rotor, (3), (4)...(mouth) (5)...Protrusion of tool, (6)... Edges of both walls of the groove, (7)...
Chamfered part, (W)...groove width, (L)...l
Circumferential distance between +%S. ,ノ・□＼ Otsuka Hozen ((・2.1 5゛]1゛′＼ (,) ＼ −／′ Figure 1 Rod 2 Da

Claims (1)

[Claims] 6 of a valve rotor for a hydraulic rotary valve in which a plurality of axial grooves are formed
In the method of chamfering both wall edges of the groove, 6 of the valve rotor
A rolling tool having a plurality of pairs of axially extending bulges spaced apart from each other at intervals approximately equal to the width of the grooves is connected to the shaft of the rolling tool and the axis of the valve rotor. After arranging the bulges parallel to each other and making the pair of bulges correspond to the grooves of the valve rotor, by pressing and rolling the tool, chamfers are formed on both wall edges of the reporter groove. Chamfering method of valve rotor for hydraulic rotary valve forming part