JPH05286446A - Part having groove on the outer periphery of cylindrical body - Google Patents

Abstract

PURPOSE:To secure a sufficient pressure resistance by forming a peripheral directional groove extending along the peripheral surface on the outer periphery of a cylindrical body, and forming the peripheral directional groove by means of plastic deformation causing a decrease in a wall thickness of a raw material. CONSTITUTION:When a slide 19 is lowered, a lower metal mold 22 pressurizes operating oil of a hydraulic cylinder 24, and lowers while receiving a cushioning operation caused by the reaction, and a molding punch 23 squeezes the inner periphery of a cylindrical raw material B from below, so that the cylindrical raw material B is expanded outward in the diametrical direction as a whole. The outer peripheral side is swollen, and is filled in a cavity 11a of an inner die 11. In this case, The cylindrical raw material B is sandwiched between a knockout metal mold 14 and the lower metal mold 22, and a width directional wall movement is regulated, and a wall thickness is also decreased at least in the bottom part of a peripheral directional groove 1 of a cylindrical body A, and the mechanical strength can be increased in the vicinity of the bottom part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a part having a groove on the outer circumference of a cylindrical body, for example, a valve sleeve for a rotary valve.

[0002]

2. Description of the Related Art Conventionally, in a rotary valve used in a power steering apparatus or the like, a valve sleeve made of a cylindrical body is rotatably fitted around the outer circumference of a valve rotor having a plurality of axial grooves formed therein. (See, for example, Japanese Utility Model Laid-Open No. 61-87776). A plurality of circumferential grooves are formed on the valve sleeve along the outer circumference of the cylindrical body. A part of this circumferential groove serves as an oil passage, and the other circumferential groove is O
It is for mounting a seal member such as a ring. Further, a plurality of axial grooves that can overlap the axial grooves of the valve rotor are formed on the inner circumference of the valve sleeve. Then, by relatively rotating the valve rotor and the valve sleeve, it is possible to control the supply and discharge of the hydraulic oil to and from the power cylinder according to the rotational displacement. The axial groove of the valve sleeve is sealed by a sealing portion integrally provided on the inner circumference of the cylindrical body or a sealing ring fitted on the end surface of the cylindrical body. The valve sleeve is formed by cutting a cylindrical material. The outer circumferential groove of the valve sleeve is formed by turning, and the inner circumferential axial groove is formed by broaching. ..

[0003]

In the above valve sleeve, since a high pressure is applied to the axial groove and a part of the circumferential groove, a large pressure resistance is required for the groove portion.
However, the valve sleeve is considerably thin at the intersection of the circumferential groove and the axial groove, and the circumferential groove is formed by turning which cannot be expected to improve mechanical strength. However, there is a problem that sufficient pressure resistance cannot be secured. Further, there is a problem in that the material yield is deteriorated and the product cost is increased due to the turning processing of the circumferential groove.

The present invention has been made in view of the above problems, and provides a component having a groove on the outer periphery of a cylindrical body which can secure sufficient pressure resistance and can reduce the manufacturing cost. The purpose is to do.

[0005]

As a component having a groove on the outer periphery of the cylindrical body of the present invention for achieving the above object,
A circumferential groove extending along the circumferential surface is formed on the outer circumference of the cylindrical body, and the circumferential groove is a groove formed by plastic deformation accompanied by a reduction in the thickness of the material. It is a thing.

The cylindrical body may constitute a valve sleeve in which an axial groove extending in the axial direction is formed on the inner circumference of the cylindrical sleeve. In this case, in the circumferential groove, A reinforcing rib may be formed in a portion corresponding to the axial groove. Further, it is preferable that at least on the outer peripheral side of the cylindrical body, the fiber flow extends in the axial direction while curving along the circumferential groove.

[0007]

According to the component having the groove on the outer circumference of the cylindrical body having the above-described structure, the circumferential groove is a groove formed by the plastic deformation accompanied by the reduction of the wall thickness of the material, and therefore is formed by turning. Compared with the case, the mechanical strength of the circumferential groove portion can be increased. Particularly, at least on the outer peripheral side of the cylindrical body, when the fiber flow extends in the axial direction while curving along the circumferential groove, the mechanical strength against a load in the radial direction can be further increased.

Further, in the case where a reinforcing rib is formed in a portion of the circumferential groove corresponding to the axial groove,
The ribs can further increase the mechanical strength.

[0009]

Embodiments will be described in detail below with reference to the accompanying drawings showing embodiments. FIG. 1 is a sectional view showing a valve sleeve of an embodiment of the present invention. The valve sleeve is formed of a single cylindrical body A, and a plurality of circumferential grooves 1 having partially different depths are formed on the outer circumference thereof. A part of this circumferential groove 1 serves as an oil passage, and another circumferential groove 1
Is for mounting an annular sealing material such as an O-ring. In addition, a plurality of axial grooves 2 extending in the axial direction are formed in parallel on the inner circumference of the cylindrical body A (see FIG. 2), and the axial grooves 2 are provided on both sides of the axial groove 2. Fitting portions 3 for fitting the annular sealing members S that seal both ends of the direction groove 2 are formed.

The outer peripheral portion of the valve sleeve bulges outward at a predetermined portion on the outer peripheral side of the cylindrical material B (see FIGS. 4 and 5) for forming the cylindrical body A by plastic working such as closed forging. The outer peripheral surface of the valve sleeve thus exhibits a plastically worked surface as a whole. Further, during the plastic working, the wall thickness is reduced at least inwardly of the bottom of the circumferential groove 1. Further, the fiber flow F of the cylindrical body A extends axially continuously at least on the outer peripheral side while curving along the circumferential groove 1 (see FIG. 3).

The cylindrical material B for forming the valve sleeve is obtained by upsetting a solid body, and the fiber flow is flowing in the axial direction, and its outer circumference and width are It has been finished to a predetermined size by turning. The material of this cylindrical material B is S4
Carbon steel such as 3C is used. On the other hand, the inner peripheral side of the valve sleeve is finished into a predetermined shape by cutting after the above plastic working. The axial groove 2 is finished by broaching, and the fitting portion 3 is finished by turning. ing.

FIG. 6 is a sectional view showing an apparatus for molding the outer peripheral portion of the valve sleeve. In this molding apparatus, an upper die set 10 is attached to a slide 19 of a press body which can be raised and lowered, and a lower die set 20 is attached to a bolster 29. The upper die set 10 includes an inner die 11 for molding the outer peripheral portion of the valve sleeve, and the inner periphery of the inner die 11 is formed with a cavity 11a corresponding to the shape of the outer peripheral portion of the valve sleeve. .. Above die 1
1 is divided into a plurality of pieces in the circumferential direction so that it can be expanded outward in the radial direction (see FIG. 7), and the outer circumference thereof is a tapered surface having a small diameter at the upper end side. The inner die 11 is fitted and retained in the annular outer die 16. The inner periphery of the outer die 16 is formed into a tapered surface having the same angle as the outer periphery of the inner die 11, and each divided piece 11b of the inner die 11 is formed along the tapered surface of the outer die 16. It is slidably fitted in the groove 16a (see FIG. 7). Therefore, the inner die 11
Can be contracted in the radial direction by being pushed deeply into the outer die 16, and can be expanded in the radial direction by being pulled out from the outer die 16. The expansion of the inner die 11 in the radial direction can be performed by pushing down the inner die 11 via the knockout die 14 by the normal pressure type slide knockout 18 of the press. The outer die 16 is held on the slide 19 by the punch holder 15. Also,
The knockout mold 14 has a molding punch 2 described later.
A hole 14a for introducing the third small diameter portion 23b is formed.

The lower die set 20 is provided with a forming punch 23 which expands the inner diameter of the cylindrical material B outward to form a predetermined shape. The forming punch 23 is formed by the inner die 11 described above.
Is slidably fitted in the central portion of the lower die 22 arranged so as to face. A small diameter portion 23b for inserting and holding the cylindrical material B is formed at an upper end portion of the forming punch 23, and a taper portion for squeezing the inner circumference of the cylindrical material B is formed continuously under the small diameter portion 23b. 23a is formed.

The lower die 22 is held slidably in the vertical direction by a die holder 25 fixed to a bolster 29, and the bottom side thereof is connected to a piston 24a of a hydraulic cylinder 24 via a cushion pin 21. Has been done. The hydraulic cylinder 24 is fixed to a bolster 29, and the hydraulic fluid supplied to the hydraulic chamber 24b of the hydraulic cylinder 24 causes the lower die 22 to move to the piston 24a.
It is supported so that it can be buffered via.

Further, on the outer periphery of the forming punch 23,
A knockout ring 26 for knocking out the cylindrical body A after completion of molding is arranged, and by the bed knockout 30 of the press, the knockout ring 26 and the lower die 22 are knocked out via the knockout pins 27 and 28, The cylindrical body A after molding can be taken out.

In order to mold the outer peripheral portion of the valve sleeve using the molding apparatus having the above-mentioned structure, as the cylindrical material B, for example, as shown in FIG. 4, the outer diameter d1 is the minimum groove diameter D1 ( The length L in the axial direction is the same as or slightly longer than the axial length L1 (see FIG. 3) of the completed product. However, as the cylindrical material B, as shown in FIG.
The diameter d1 on the small diameter side is approximately the same as the minimum groove diameter D1 of the valve sleeve, the diameter d2 on the large diameter side is approximately the same as the maximum groove diameter D2 of the valve sleeve, and the axial length L is the valve sleeve. It is also possible to use a length equal to or slightly longer than the axial length L1 of. In addition, the inner diameter d3 of each of the cylindrical materials B is calculated so as to have the same volume as that of the completed product, and thus the inner diameter d3 is smaller than the minimum inner diameter of the completed product.

Next, a molding method using the above-mentioned molding apparatus will be described. First, the cylindrical material B is heated to room temperature or a warm region of 700 ° C. to 900 ° C. depending on the material, and is shown in FIG. State, the small diameter portion 23b of the forming punch 23
Insert into. At this time, a cylindrical material B having a step portion X on the outer circumference
With respect to, the step portion X side is inserted downward. Then, when the slide 19 is lowered in the above state to start the molding, as shown in FIG.
The lower surface of the inner die 11 contacts the upper surface of the lower die 22. Then, the inner die 11 is gradually introduced into the inside of the outer die 16 and finally is completely contracted in the radial direction. When the slide 19 further descends from this state, the lower mold 22
However, the hydraulic oil of the hydraulic cylinder 24 is pressurized and descends while receiving a cushioning effect due to its reaction, and the forming punch 23 squeezes the inner circumference of the cylindrical material B from below.
By the ironing by the forming punch 3, the cylindrical material B is expanded radially outward as a whole, and the outer peripheral side is bulged to fill the cavity 11a of the inner die 11 (see FIG. 8b). At this time, the cylindrical material B is held between the knockout mold 14 and the lower mold 22 to restrict movement of the meat in the width direction, and at least at the bottom of the circumferential groove 1 of the cylinder A. And the mechanical strength near the bottom is increased. Next, slide 1
When 9 reaches the bottom dead center, the slide 19 starts to rise, and with this rise, the lower mold 22 rises due to the restoring force of the pressurized hydraulic oil (see FIG. 8c). And
When the lower die 22 moves up by a predetermined stroke, the inner die 11 is pushed down by the action of the atmospheric pressure type slide knockout 18, and the inner die 11 is expanded in the radial direction accordingly (see FIG. 8d). ..

After that, the slide 19 is further raised,
A bed knockout 30 synchronized with the slide 19 lifts the lower die 22 to the uppermost end via the knockout pins 27 and 28 and the knockout ring 26, and knocks out the molded product to form a cylinder having a circumferential groove 1 on the outer circumference. Body A can be obtained (see Figure 8e). Then, the inner peripheral surface of the cylindrical body A obtained as described above is broached to form the axial groove 2, and the fitting portion 3 for fitting the sealing member S is turned and finished. Thereby, the valve sleeve shown in FIG. 1 can be obtained.

The valve sleeve thus obtained has a circumferential groove 1 for mounting a seal member such as a seal ring.
However, since it is formed by plastic deformation, the roughness of the groove surface becomes dense and the sealing performance by the seal member improves. Furthermore, at least at the bottom of the circumferential groove 1, the cylindrical material B
Since the plastic deformation accompanied by the decrease in the wall thickness is applied, the mechanical strength of the portion can be increased. Moreover, at least on the outer peripheral side of the cylindrical body A, the fiber flow F
However, since it extends in the axial direction while curving along the circumferential groove 1, it is possible to further increase the mechanical strength against a radial load.

Further, according to the above method for manufacturing the valve sleeve, the circumferential groove 1 is formed by bulging the outer peripheral predetermined portion of the cylindrical material B outward in the radial direction, so that the circumferential groove 1 can be easily formed. In addition, it is possible to form with good accuracy, and it is also possible to ensure good accuracy between the circumferential grooves 1 having different depths. At the same time as the plastic working of the valve sleeve, inside the predetermined circumferential groove 1 and in the axial groove 2
The reinforcing rib 4 may be formed at a portion corresponding to (see FIG. 9), and in this case, the mechanical strength of the portion can be further increased.

If a protrusion for forming the axial groove 2 is formed on the forming punch 23, the axial groove 2 is formed.
Can also be simultaneously molded by the plastic working. Further, as the valve sleeve of the present invention, as shown in FIG. 10, one end of the axial groove 2 is sealed by an annular projection 5 integrally formed on the inner periphery of the one end side of the cylindrical body A. Various design changes can be made.

The cylindrical material B for forming the valve sleeve may be manufactured by cutting a solid body, or a hollow material may be used. On the other hand, as the forming method of the circumferential groove 1, in addition to the closed forging, other plastic working methods accompanied by a decrease in wall thickness such as rolling can be adopted. Furthermore, the present invention can be implemented by being applied to various parts having a groove on the outer periphery other than the valve sleeve.

[0023]

As described above, according to the component having the groove on the outer periphery of the cylindrical body of the present invention, since the circumferential groove is formed by the plastic deformation accompanied by the reduction of the wall thickness of the material, The mechanical strength at the bottom of the circumferential groove can be increased.
Therefore, it is possible to secure sufficient pressure resistance as compared with the conventional turned product. Further, since the material yield can be improved with the plastic working of the circumferential groove, the manufacturing cost can be reduced accordingly.

Particularly, at least on the outer peripheral side of the cylindrical body, when the fiber flow extends in the axial direction while curving along the circumferential groove, the fiber flow is cut off in the pressure load direction. Therefore, the mechanical strength can be further increased. Further, in the case where a reinforcing rib is formed in a portion of the circumferential groove corresponding to the axial groove, the mechanical strength of the portion can be further increased.

[Brief description of drawings]

FIG. 1 is a sectional view of a valve sleeve showing an embodiment of the present invention.

FIG. 2 is a right side view of the valve sleeve.

FIG. 3 is an enlarged cross-sectional view showing a fiber flow flow state of the valve sleeve.

FIG. 4 is a cross-sectional view showing a cylindrical material.

FIG. 5 is a cross-sectional view showing another embodiment of the cylindrical material.

FIG. 6 is a cross-sectional view showing a valve sleeve molding device.

FIG. 7 is a cross-sectional view of a main part of a molding device.

FIG. 8 is a process drawing showing the method of manufacturing the valve sleeve.

FIG. 9 is a sectional view showing another embodiment of the valve sleeve.

FIG. 10 is a sectional view showing still another embodiment of the valve sleeve.

[Explanation of symbols]

 A cylindrical body 1 circumferential groove 2 axial groove F fiber flow 5 reinforcing ribs

Front page continued (72) Inventor Shinta Otsuka 3-5-8 Minamisenba, Chuo-ku, Osaka City Koyo Seiko Co., Ltd. Co., Ltd. (72) Inventor, Kunihiko Tanaka, No. 5, Yokaichi, Komatsu City, Ishikawa Prefecture Komatsu Ltd.

Claims (4)

[Claims] 1. A circumferential groove extending along the circumferential surface is formed on the outer periphery of a cylindrical body, and the circumferential groove is a groove formed by plastic deformation accompanied by a reduction in the wall thickness of a material. A component having a groove on the outer circumference of a cylindrical body. 2. The component having a groove on the outer circumference of the cylindrical body according to claim 1, wherein the cylindrical body constitutes a valve sleeve in which an axial groove extending in the axial direction is formed on the inner circumference thereof. 3. At least the outer peripheral side of the cylindrical body,
The component having a groove on the outer periphery of the cylindrical body according to claim 1 or 2, wherein the fiber flow extends in the axial direction while curving along the circumferential groove. 4. A component having a groove on the outer circumference of a cylindrical body according to claim 2, wherein a reinforcing rib is formed in a portion of the circumferential groove corresponding to the axial groove.