JPH0322250B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for forming chamfers on both side wall edges of a groove of a valve rotor used in a hydraulic rotary valve.

[Conventional technology]

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 the valve rotor. The valve sleeve has axial grooves that overlap each other on both sides, 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 valve 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 A chamfered portion of a predetermined shape is formed on the edge.

Methods for forming such chamfered portions have already been proposed (Japanese Patent Publication No. 4807/1983, Japanese Patent Publication No. 58/1983).
42769, etc.), but in all of these, a number of independent punches corresponding to the number of valve grooves are held by a hydraulic cylinder or a cam mechanism, and the chamfered portion is formed by pressing them against the workpiece. .

[Problem to be solved by the invention]

Therefore, the conventional chamfering device has a disadvantage in that it has a complicated mechanism and requires a large dedicated machine in which each punch is precisely arranged.

The present invention has been made in view of the above points, and is a chamfering method and device that uses jigs and tools that have a simple structure and a robust machining surface, and can also use a conventionally known general-purpose small press machine. It provides:

[Means for solving problems]

In the method of the present invention, a punch having a pair of machined surfaces that simultaneously press against both side wall edges of each single groove is placed radially outward of a workpiece in which a plurality of axial grooves have been formed in advance. After arranging the punches to face each other, by pressing the punch, the machined surfaces of the punches are brought into pressure contact with the edges of both side walls of the groove to form a chamfered portion, and an apparatus for carrying out this method is provided. has a guide hole in which a workpiece having a plurality of axial grooves formed in advance can be fitted, and a gate opening toward the guide hole from the outside in the radial direction is provided corresponding to each of the grooves. and a pair of machined surfaces for simultaneously pressing and chamfering both side wall edges of each of the single grooves at the tip, and inserting the tip into the gate with the tip facing each of the grooves. It is configured to include a plurality of arranged punches, and an actuation mechanism that presses each of the punches inward in the radial direction by moving a contact surface of a pressing member into contact with the back surface of these punches, and further includes: In addition, a tapered surface is formed as a contact surface of the pressing member, and the punch is pressed by lowering the pressing member and bringing the tapered surface into contact with the back surface of the punch.

[Effect]

According to this invention, a chamfer is formed by pressing the punch inward in the radial direction to bring the pair of machined surfaces of the punch into pressure contact with the edges of both side walls of the groove of the workpiece.

〔Example〕

The present invention will be explained below based on illustrated embodiments.
1 to 3 show a valve rotor chamfering device according to an embodiment of the present invention, which is composed of an upper mold 2 and an upper mold 4. FIG. The lower die 4 consists of two discs 6 and 8.
A work holder 10 including a punch 1 to be described in detail later.
2, and a cylindrical workpiece 1 in which a plurality of axial grooves 17 are formed in advance in a guide hole 16 at the center of the annular member 14.
8 are fitted to hold the workpiece 18 in an upright state. A sprite groove is formed in the hole 20 in the center of the upper disc 6, and by inserting a spline formed at the end 22 of the workpiece 18 into this groove, the workpiece 18 can be positioned in the circumferential direction. A hole 24 having a smaller diameter than the hole 20 in the upper disk 6 is formed in the lower disk 8, and the stepped portion of the workpiece 18 touches the periphery of the hole 24 in the disk 8. By contacting it, it functions as a work stopper. Note that both discs 6 and 8 are positioned by pins inserted through holes 25 (see FIG. 3).

The annular member 14 includes an upper ring 26 and a lower ring 2
8 are stacked on top of each other, and the lower ring 28
With the two discs 6 and 8 accommodated in the circular recess 30 formed on the lower surface of the work holder 1,
0 and are integrally fixed by bolts 34. Six radial notches are formed at equal intervals on the upper surface of the lower ring 28, and a punch gate 36 through which the punch 12 is inserted is formed by the ring 28 and the upper ring 26 stacked on top of the ring 28. ing. The guide hole 16 side opening of each punch gate 36 is set to face each groove 17 of the work 18 positioned by the work holder 10.

The punch 12 has a rod shape with a pair of processing surfaces 38 (see FIG. 4) formed at its tip, and a roller 40 is rotatably attached to its rear end surface. This punch 12 is inserted into each of the six punch gates 36 of the annular member 14, and both processed surfaces 38 at the tip are arranged opposite to both side walls 42 of each groove 17 of the workpiece 18. Disc springs 44 are provided at the portions of each punch 12 that protrude outward from the punch gate 36, so that the tip of the punch 12 is normally positioned within the punch gate 36.

On the other hand, the upper mold 2 is equipped with six pressing members 50 that are slidable in the vertical direction with respect to both the face plate 46 and the holder block 48 that are fixed to each other, and an operating mechanism 51 that presses the punch 12 by these members. is configured. This pressing member 50 is arranged so as to be located radially outward of each punch 12 provided on the lower mold 4, and a lower surface 52 on the punch 12 side is formed in a tapered shape. and,
These pressing members 50 are supported by springs 56 housed in recesses 54 formed in the upper part of the holder block 48.
is constantly urged downward by. Further, an adjusting screw 57 that also serves as a spring seat for the spring 56 is screwed onto the upper surface of the pressing member 50.
This makes it possible to adjust the stroke end when the pressing member 50 descends.

Further, in the center of both the upper mold 2 and the lower mold 4, a center 62, which is biased toward each other by springs 58 and 60 provided on the back side of each, is provided.
64 are arranged, and these two centers 62, 6
4, the workpiece 18 is held between the upper and lower sides while chamfering is performed. Further, the spring 58 of the upper center 62 has a stronger urging force than the spring 60 of the lower center 64, so that the workpiece 1
8 against the work stopper, that is, the disk 8.

The process of chamfering using the chamfering device having the above configuration will be described. First, a round bar-shaped workpiece 18 in which a plurality of (six in this embodiment) axial grooves 17 have been formed is inserted into the guide hole 16 of the annular member 14, and the splines of the workpiece 18 are aligned with the upper disc 6. The workpiece is positioned in the circumferential direction by meshing with the spline. At this time, each punch 12 is held in a radially outwardly retreated position by a disc spring 44, and the machined surface 38 at the tip of the punch 12 faces the side walls 42 of the groove 17 of the workpiece 18 without contacting them. are doing.

Next, the upper mold 2 is lowered. As the upper mold 2 descends, the tapered surface 52 of the pressing member 50 is pressed against the punch 1.
2, the punch 12 is pushed inward in the radial direction as it comes into contact with the roller 40 at the rear end, and the processed surface 38 at the tip of the punch 12 is pressed against the edges of both side walls of the groove 17, forming a chamfered portion. do. In this way, chamfering can be performed using extremely simple jigs and tools and a simple process. Furthermore, according to the conventional chamfering method, as shown in FIG. Therefore, during processing, there was a problem in terms of strength, as the protrusions were susceptible to breakage due to the repulsive force in the direction of the arrow in the figure. In contrast, in the present invention, as shown in FIG.
Since one groove 17 is chamfered with one punch 12, the repulsive stress during pressing is directed in the direction of the arrow in the figure, so that the durability of the punch 12 can be improved without causing problems in strength. In addition, in the device of this embodiment, the pressing member 50 is provided corresponding to each punch 12, and each is configured to operate independently, so that various errors such as an error in the outer diameter of the workpiece 18 can be avoided. can be absorbed to form a chamfered portion of uniform depth.

When the upper mold 2 is raised after chamfering as described above, the tapered surface 52 of the pressing member 50 comes off the roller 40 of the punch 12, and the force pushing the punch 12 inward is removed, and each punch 12 They are retracted radially outward by the disc springs 44 provided, returning to a state of non-contact with the workpiece 18, and the workpiece 18 can be taken out from the lower die 4.

In this example, a round bar with six grooves 17 formed at equal intervals in the circumferential direction was used as the workpiece 18, but if the number of grooves 17 is 4, 8, etc. Needless to say, the number of punches 12 corresponding to this number may be arranged.

6 to 8 show other embodiments of the invention.
The lower mold 4 is equipped with a work holder 6 fixed to a die block 70, and a work 18 having the same structure as in the above embodiment is positioned by splines and held in an upright state. An annular punch holding member 14 is fixed on the work holder 6.
The center of the annular member 14 is a guide hole 16 that supports the outer peripheral surface of the workpiece 8.
Six punch gates 36 are formed radially toward the hole 6. Guide hole 1 of each punch gate 36
The opening on the 6th side corresponds to each axial groove 17 positioned by the work holder 6, and each punch 12 arranged in these punch gates 36.
A pair of machined surfaces 38 at the tip face edges of both side walls of each groove 17. Also, each punch 1
The two rear end surfaces 13 are formed in a tapered shape, and a wire ring 72 having spring properties is disposed on the rear end side of these punches 12. Therefore, when the punch 12 is in the firing operation, the tip end surface is aligned with the punch gate 36.
The workpiece 18 is held in a position where it does not come into contact with the workpiece 18.

On the other hand, the upper die 2 has a cylindrical pressing member 74 attached to the upper ram. A tapered surface 76 that substantially coincides with the tapered surface 13 at the rear end of the punch 12 is formed on the lower inner circumferential surface of the cylindrical pressing member 74, and as the pressing member 74 descends, the tapered surface 76 is formed on the punch 12. The punch 12 is pushed inward while slidingly contacting the tapered surface 13 of the punch 12.

In the apparatus of this embodiment, similarly to the above embodiment, the central guide hole 1 of the annular punch holding member 14 has the punch 12 disposed in each punch gate 36.
After inserting the workpiece 18 into the workpiece 6 and positioning it in the circumferential direction, the pressing member 74 is lowered. The tip processed surfaces 38 of each punch 12 pushed inward by the downward movement of the pressing member 74 are pressed against the edges of both side walls of the corresponding groove 17, thereby forming a chamfered portion.

Thereafter, when the pressing member 74 is raised, each punch 12 is returned to its original state by the wire ring 72 on the rear end side. Note that the mechanism for retracting each punch 12 is not limited to a wire ring, and it goes without saying that the mechanism for retracting each punch 12 may be, for example, a notch formed in the upper or lower surface of the rear part of the punch 12, into which a snap ring is fitted.

As described above, in this embodiment as well, chamfering can be performed in a simple process using extremely simple jigs and tools.

The example shown in FIG. 9 uses a so-called rotary cam that rotates a cylindrical member 80 having a protrusion 78 formed on its inner surface as an operating mechanism for pressing the punch 12. In this example, as the cylindrical member 80 rotates, the protrusions 78 successively hit the rear end surface of the punch 12, causing the punch 12 to come into pressure contact with the workpiece 8. In this case, from the viewpoint of the balance of the force applied to the workpiece 18, it is preferable to provide the protrusions 78 at two opposing locations as shown in the figure, but it is also possible to sequentially process the workpiece 18 using only one protrusion 78.

〔Effect of the invention〕

As described above, according to the method and apparatus of the present invention, tools and jigs with a simple structure and a robust machining surface are used, and moreover, the valve can be efficiently processed by a general-purpose small press machine without the need for a special dedicated machine. The rotor can be chamfered.

[Brief explanation of drawings]

1 to 3 show a chamfering device according to an embodiment of the present invention, FIG. 1 is a longitudinal sectional view taken along the - line in FIGS. 2 and 3, and FIG. 2 is a plan view of the upper die. ,
FIG. 3 is a plan view of the lower die, and FIGS. 4 and 5 are explanatory diagrams showing the state of pressure contact between the punch and the workpiece.
FIG. 4 shows one embodiment of the present invention, FIG. 5 shows an example of the conventional technology, and FIGS. 6 to 8 show other embodiments. FIG. 6 is a longitudinal sectional view, and FIG. FIG. 8 is a side view of the main part, and FIG. 9 is a diagram showing the main part of another embodiment. 12... Punch, 14... Annular member, 16...
Guide hole, 17... Groove of workpiece, 18... Workpiece, 36... Gate, 38... Machining surface of punch,
51...Operating mechanism.

Claims (1)

[Scope of Claims] 1. A punch having a pair of machined surfaces that simultaneously press against both side wall edges of each single groove is provided radially outward of a workpiece in which a plurality of axial grooves have been previously formed. A valve rotor for a hydraulic rotary valve, characterized in that the machined surface of the punch is brought into pressure contact with the edges of both side walls of the groove to form a chamfered portion by pressing the punch after being placed facing the groove. Chamfering method. 2. The hydraulic rotary valve according to claim 1, wherein the same number of punches are arranged corresponding to each of the plurality of grooves formed in the workpiece, and chamfered portions are simultaneously formed in each groove. How to chamfer a rotor. 3. It has a guide hole in which a workpiece in which a plurality of axial grooves are formed in advance can be fitted, and a gate that opens toward the guide hole from the outside in the radial direction is provided corresponding to each of the grooves. an annular member, and a pair of machining surfaces for simultaneously pressing and chamfering both side wall edges of each single groove at the tip,
A plurality of punches are inserted into the gate with the tips thereof facing each of the grooves, and the contact surfaces of the pressing members are brought into contact with the back surfaces of these punches to press each punch radially inward. A chamfering device for a valve rotor for a hydraulic rotary valve, characterized in that it is equipped with an operating mechanism for chamfering a valve rotor for a hydraulic rotary valve. 4. The chamfering device for a valve rotor for a hydraulic rotary valve according to claim 3, wherein the operating mechanism presses a plurality of punches simultaneously. 5. The actuating mechanism includes a pressing member made of a cylindrical member having a protrusion on the inner surface, and presses the punch by rotating the cylindrical member and bringing the protrusion into contact with the back surface of the punch. A chamfering device for a valve rotor for a hydraulic rotary valve according to scope 3. 6. The chamfering device for a valve rotor for a hydraulic rotary valve according to claim 3, wherein the tip of the punch is retracted into the gate when the pressing force from the operating mechanism is not acting on the punch. 7. When the pressing force from the operating mechanism is not acting on the punch, each punch is biased radially outward by an elastic member provided at the rear of the punch, and the tip of the punch retreats into the gate. A chamfering device for a valve rotor for a hydraulic rotary valve according to claim 3. 8. It has a guide hole in which a workpiece in which a plurality of axial grooves are formed in advance can be fitted, and a gate that opens toward the guide hole from the outside in the radial direction is provided corresponding to each of the grooves. an annular member, and a pair of machining surfaces for simultaneously pressing and chamfering both side wall edges of each single groove at the tip,
A plurality of punches are inserted into the gate with the tips thereof facing each of the grooves, and the contact surfaces of the pressing members are brought into contact with the back surfaces of these punches to press each punch radially inward. The pressing member of the operating mechanism has a tapered surface formed as a contact surface, and the punch is pressed by lowering the pressing member and bringing the tapered surface into contact with the back surface of the punch. A chamfering device for a valve rotor for a hydraulic rotary valve, characterized by: 9. The chamfering device for a valve rotor for a hydraulic rotary valve according to claim 8, wherein the back surface of the punch is formed in a tapered shape. 10. The chamfering device for a valve rotor for a hydraulic rotary valve according to claim 8, characterized in that a roller is provided on the back surface of the punch. 11. The chamfering device for a valve rotor for a hydraulic rotary valve according to claim 8, wherein the pressing member has a cylindrical shape and simultaneously presses a plurality of punches using a tapered surface formed on its inner surface. . 12. The actuating mechanism includes the same number of pressing members as the number of grooves in the workpiece, and the pressing force of each of these pressing members can be individually adjusted by an adjustment screw. Chamfering device for valve rotor for hydraulic rotary valves.