JP3007181B2 - Cylindrical hollow body circumferential groove forming tool, forming apparatus and forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical hollow body (in the present specification, a cylindrical hollow body is formed by rotating a straight line or a curve at a position separated from a central axis by a predetermined distance around the central axis. Forming a groove parallel to the axial direction of the cylindrical hollow body on the inner circumferential surface of the hollow body having an envelope curved surface formed as an inner circumferential surface). It is.

[0002]

2. Description of the Related Art A plurality of grooves parallel to the axial direction and formed at equal intervals in the circumferential direction at a substantially central portion in the axial direction of a peripheral surface of a cylindrical body include, for example, a rotary control valve of a power steering mechanism. That is, there is a stub shaft sleeve incorporated in the rotary servo valve.

[0003] In a power steering mechanism which is a kind of hydraulic servo mechanism for reducing the steering force of an automobile,
The control valve includes a spool servo valve, a rotary servo valve, and the like. The rotary servo valve is configured as shown in FIGS.

[0004] The rotary servo valve 0 includes a valve housing 1, a stub shaft sleeve 2 fitted in the valve housing 1 in an oil-tight and rotatable manner, and a rotatable inner circumferential surface of the stub shaft sleeve 2. The valve housing 1 is formed with an oil supply port 4 and an oil discharge port 5 which respectively communicate with a discharge port and a suction port of a hydraulic pump (not shown). A left cylinder port 6 and a right cylinder port 7 communicating with both the left and right cylinder chambers are formed.

A circumferential lubrication groove 8 is formed on the outer peripheral surface of the stub shaft sleeve 2 and communicates with the lubrication port 4. The circumferential lubrication groove 8 communicates with the left cylinder port 6 and the right cylinder port 7. Circumferential left cylinder groove 9 and circumferential right cylinder groove 10
Are formed on both sides in the axial direction. The stub shaft sleeve 2 is formed with four oil supply passages 11 which are directed at the central axis and whose outer ends are opened in the circumferential oil supply groove 8 at equal intervals in the circumferential direction. A left cylinder passage 12 and a right cylinder passage 13 are formed on both sides at an angle of 22.5 ° about the center axis of the stub shaft sleeve 2 and directed toward the axis of the stub shaft sleeve 2, respectively. The outer ends of the passage 12 and the right cylinder passage 13 are open to the circumferential left cylinder groove 9 and the circumferential right cylinder groove 10, respectively.

Further, on the inner peripheral surface 2a of the stub shaft sleeve 2, each left cylinder passage 12, right cylinder passage 13
And the center of the groove coincides with the center of the groove, and four axial grooves 14 and 15 are formed alternately in parallel with the axial direction of the stub shaft sleeve 2, for a total of eight grooves, that is, the left cylinder passage 12 and the right cylinder passage The inner end of 13 is open to each axial groove 14 and axial groove 15, respectively.

Further, on the outer peripheral surface of the stub shaft 3, axial grooves 16, 17 having a width equal to the width of the portion sandwiched between the axial grooves 14, 15 of the stub shaft sleeve 2 are alternately formed in the circumferential direction. It is formed at intervals. An oil drain passage 19 is formed to communicate the center hole 18 of the stub shaft 3 with the axial groove 17, and the center hole 18 communicates with the oil drain port 5 via another oil drain passage 20.

The stub shaft 3 is connected to a steering wheel (not shown), and the stub shaft sleeve 2 is connected to a pinion 22 meshing with a rack 21 integrated with a piston of a power cylinder (not shown). Correspondingly, when the stub shaft 3 rotates in any direction by a predetermined angle, the axial groove 16 of the stub shaft 3 communicates with one of the axial grooves 14, 15, for example, the axial groove 14. The pressure oil flowing into the axial groove 16 via the directional oil supply groove 8 and the oil supply passage 11 is illustrated from the axial groove 14 via the left cylinder passage 12, the circumferential left cylinder groove 9, and the left cylinder port 6. The piston moves to the right after flowing into the left cylinder chamber of the unpowered power cylinder, and the wheels turn in the required direction. The description of the state of oil discharge in the right cylinder chamber is omitted.

In addition, the pinion 22 and the stub shaft sleeve 2 rotate in the same direction as the rotation direction of the stub shaft 3 in response to the movement of the piston and the rack 21, and the stub shaft sleeve 2 rotates to a rotation angle equal to the rotation angle of the stub shaft 3. When is rotated, the communication between the axial groove 16 and the axial groove 14 is cut off, and the supply of the hydraulic oil to the cylinder is stopped.

In the rotary servo valve 0 described above, in order for the power steering mechanism to operate smoothly and accurately, the axial grooves 14 and 15 of the inner peripheral surface 2 a of the stub shaft sleeve 2 and the outer peripheral surface of the stub shaft 3 are required. The axial grooves 14, 15 and the axial grooves 16, 17 are adjusted so that the center position accuracy and the width accuracy of the axial grooves 16, 17 are maintained at predetermined levels.
Need to be processed.

When the axial grooves 16, 17 are formed in the stub shaft 3, the axial grooves 16, 17 are exposed on the outer peripheral surface of the stub shaft 3, so that the machining is relatively easy. When the axial grooves 14 and 15 are formed in the shaft sleeve 2, the axial grooves 14 and 15 are
Since the stub shaft sleeve 2 is located on the inner peripheral surface 2a and is hidden from the outer periphery by the stub shaft sleeve 2, machining as described below was difficult.

[0012]

2. Description of the Related Art Conventionally, in order to overcome such difficulties, as shown in FIGS. 10 and 11, an inner peripheral surface 02 of a hollow cylinder 01 is provided over the entire axial length thereof. A vertical groove 03 oriented in the axial direction is formed by broaching, holes 04 deeper than the vertical groove 03 are formed at both ends of the vertical groove 03, and a ring 05 closing both ends of the vertical groove 03 is fitted into the hole 04. By attaching, a vertical groove 03 is formed substantially in the axial center of the inner peripheral surface 02 of the hollow cylinder.
There was a split-type stub shaft sleeve that constituted.

This rotary body can freely form the cross section of the vertical groove 03 into a required shape. However, in order to prevent oil leakage from the vertical groove 03, the machining accuracy of the hole 04 and the ring 05 must be increased. In addition, the number of parts and the number of processing steps must be increased to increase the cost.

Further, when forming an axial groove on the inner peripheral surface of the valve body with a ball end mill, it is difficult to maintain the groove width accuracy at a high level, and the tool life is short and the processing time is long. Low productivity.

Further, when a slotter is used, the mechanism becomes complicated and the cost becomes high, and skill and time are required for dimensional adjustment at the time of changing the blade, and the machining allowance is reduced because the machining allowance per one operation is small, so that the production time is also increased. Poor.

Further, as described in Japanese Patent Publication No. 1-48090, in the case of forming an axial groove on the inner peripheral surface of a hollow cylinder by forging, the groove edge can be formed in a sharp shape. In addition, when the mold is worn, there is a disadvantage that the accuracy of the groove width is greatly reduced.

[0017]

SUMMARY OF THE INVENTION The present invention relates to an invention in which an axial groove is formed in a peripheral surface of a cylindrical hollow body in which such a problem has been solved. Forming a groove parallel to the axial direction in the portion, the forming tool having a diameter and a groove that can be freely and removably fitted into a hollow space in the cylindrical hollow body. A rotary blade having a width capable of rotating the blade, a width of a rotary blade pivot portion of the blade holder is smaller than a diameter of the rotary blade, and a cross-sectional shape and a size of the blade holder are in the cylindrical hollow body along a longitudinal direction thereof. A blade holder having a cross-sectional shape and dimensions that can be freely and removably fitted into a hollow space, and a plurality of gears arranged in a longitudinal direction of the blade holder to supply power to the rotary blade. A rotary gear of the blade holder At the center in the thickness direction of the pivot portion, there is formed a space in which the rotating blade can be sandwiched and rotatably pivoted about a central axis perpendicular to the axis of the cylindrical hollow body so as to be rotatable. A space in which the gear train can be arranged is formed on one outer side in the thickness direction of the tool, and an input shaft is integrally connected to an input end gear of the gear train, and the output shaft of the gear train is provided with the input shaft. The rotary blade is integrally connected.

Since the present invention is configured as described above, the blade holder is inserted into the hollow space of the cylindrical hollow body from the opening end of the hollow space, and the longitudinal direction of the blade holder is adjusted. In a state where the cylindrical hollow body is oriented parallel to the axial direction, the rotary blade is applied to a required portion of an inner peripheral surface of the cylindrical hollow body where a groove is to be formed, and the input shaft is rotationally driven. By pushing the blade holder into a predetermined depth and moving it along the longitudinal direction, a groove parallel to the axial direction can be formed on the peripheral surface of the cylindrical hollow body.

According to the present invention, there is further provided a molding apparatus for forming a groove parallel to the axial direction at a substantially central portion in the axial direction of a peripheral surface of a cylindrical hollow body. A tool for forming a circumferential groove in a cylindrical hollow body, tool support means for supporting both ends of the forming tool, tool driving means connected to an input shaft of the forming tool to rotate the rotary cutter, and a workpiece. A cylindrical hollow body supporting means for supporting the cylindrical hollow body, and either or both of the tool supporting means and the cylindrical hollow body supporting means in a direction relatively parallel to the groove and in a depth direction of the groove; By using such a molding device, it is possible to easily and reliably perform the axial groove forming process on the peripheral surface of the cylindrical hollow body. it can.

Further, the present invention relates to a molding method for forming a groove parallel to the axial direction substantially at the center of the peripheral surface of the cylindrical hollow body in the axial direction, wherein the rotary blade is formed in the axial direction of the cylindrical hollow body. In a state where the center axis of the cylindrical hollow body is oriented at a right angle, the rotary blade is advanced into the hollow space of the cylindrical hollow body, and the rotary blade is driven to rotate at a predetermined depth toward the inner peripheral surface of the cylindrical hollow body. After pushing a predetermined stroke in the axial direction of the cylindrical hollow body and cutting one groove, the cylindrical hollow body is pushed in a predetermined depth toward a diameter portion of the inner peripheral surface facing the cut groove. The method is characterized in that a groove parallel to the axial direction of the cylindrical hollow body is formed by cutting the other groove by reciprocating the predetermined stroke in the axial direction of the hollow body. By using it, the cylindrical hollow can be formed in one groove forming operation. The opposite diameter position of the inner peripheral surface, one strip parallel to the axial direction groove, total 2 Article can be formed simultaneously.

[0021]

[Embodiment] An embodiment of the present invention shown in FIGS. 3 to 9 will be described below. The axial length of the stub shaft sleeve 2 which is a kind of a cylindrical hollow body is about 35 mm, the outer diameter of the stub shaft sleeve 2 is also about 35 mm, and the inner diameter of the hollow cylindrical inner peripheral surface 2a of the stub shaft sleeve 2 is about 22 mm. The width of the axial grooves 14 and 15 parallel to the axial direction of the stub shaft sleeve 2 is about 4.5 mm, the depth is about 1 mm, and the length is about 17
mm. The forming tool 30 includes a rotary blade 31, a blade holder 32, and a gear train 41. The tooth width of the rotary blade 31 is set to about 4.5 mm, and its diameter is set to about 20 mm.

The blade holder 32 has a spacer 33 having a thickness very slightly (about 10 μm) thicker than the tooth width of the rotary blade 31.
And 4.3 mm thick side plates 34 and 35 sandwiching the spacer 33 from both sides, and the tip portion 36a has the same thickness as the spacer 33, and the base portion 36b has the thickness of the spacer 33, the side plate 34, It consists of a receiving piece 36 set to 13.1 mm which is the sum of each thickness of 35, and the relative position in the longitudinal direction of the spacer 33, side plates 34, 35 is fixed by knock pins 37 penetrating them. Left side plate
The bolts 38 are screwed into the side plate 35 through the bolts 34 and 35 and are integrally connected by two bolts 38. Further, the side plates 34 and 35 and the receiving piece 36 , 35 and the tip 36 of the receiving piece 36
While the relative positions are fixed by two knock pins 39 penetrating through the side plate a, the two bolts 38 are screwed into the side plate 35 through the side plate 34 and the spacer 33 and integrally joined together. The side plates 34, 35 and the receiving piece 36 are relatively fixed by two knock pins 39 penetrating the tip portions 34a, 35a of the side plates 34, 35 and the tip portion of the receiving piece 36. While the position is fixed, the side plate 34 and the distal end portions 34a and 33a of the spacer 33 are integrally connected by bolts 40 screwed to the distal end portion 35a of the side plate 35. .

Further, the gear train 41 includes an input gear 42 and an intermediate gear.
The input gear 42 includes spacers 33, side plates 34 and 35, and each end portion 33a, 34a, 35
a rotatably penetrated through the input shaft 46, and the intermediate gears 43, 44 are fixedly inserted through the spacers 33, the end portions 33a, 34a, 35a of the side plates 34, 35.
The output gear 45 and the rotary blade 31 are integrally fitted to an output shaft 49 rotatably penetrating the tip portions 34a and 35a of the side plates 34 and 35, and the input shaft When a rotational force is applied to 46, the rotary blade 31 is driven to rotate.

However, the side plate 34 has a gear train.
Notch 34 so that each input gear 42, intermediate gears 43 and 44, and output gear 45 of 41 do not protrude significantly to the surface of the side plate 34.
c is formed, and the cutting oil discharge hole 36 is formed in the base 36b of the receiving piece 36.
c is formed, and a cutout 48a is formed in the intermediate shaft 48 so that the rotary blade 31 can rotate.

The spacer 33, the side plates 34, 35
The width of the front end 33a, 34a, 35a is about 15.7 mm, and the base 33
The width of b, 34b, 35b is set to 30 mm, and the base 36 of the receiving piece 36
The width of b is set to 20 mm, and as shown in FIG. 3, the input gear 42, the intermediate gears 43 and 44, and the output gear 45 are respectively a spacer 33, the tip portions 33a of side plates 34 and 35,
The rotary blade 31 is housed in the width of 34a, 35a, and protrudes outward from the distal ends 33a, 34a, 35a.

In the molding apparatus 50, a tool support stand 52 and a holder support stand 53 are integrally erected on a base 51, and two slide rails are provided on the upper part of the tool support stand 52.
54, a holder slider unit 55 is slidably mounted on the slide rail 54, and a tool support stand is provided.
A holder slider unit 55 is integrally attached to a tip of a piston rod 56a of an air cylinder 56 mounted on the holder 52, and the holder slider unit 55 can reciprocate right and left in response to expansion and contraction of the piston 56a of the air cylinder 56. It has become.

The holder slider unit 55 is provided with a positioning pin 57 which can be fitted into the hole 35c of the side plate 35 of the blade holder 32, and also has a blade holder.
A fastening bolt 58 that can fix the screw 32 is screwed.

Further, in the holder support stand 53,
A holder holder 59 is provided, which is capable of removably fitting the receiving piece 36 of the blade holder 32 and gripping the receiving piece 36 with the tightening bolt 60.
A cutting oil passage 59a communicating with a cutting oil discharge hole 36b provided in the receiving piece 36 of the blade holder 32 is formed.
Reference numeral 59 denotes a mounting bolt 61 that is detachably attached to the holder support stand 53.

A work support 62 is provided between the tool support stand 52 and the holder support stand 53. A work front / rear slider 63 is attached to the work support 62 so as to be slidable back and forth. 4mm before and after
A work left / right reciprocating drive 64 is provided to reciprocate the work.A work left / right slider 65 is mounted on the work front / rear slider 63 so as to be slidable left and right. A part 66 is provided.

An index unit 67 is removably mounted on the upper surface of the left and right sliders 65 by mounting bolts 68, and an upright portion 67a of the index unit 67 has a gap that can move back and forth by 5 mm or more with respect to the holding bracket receiver 59. A U-shaped space 67b surrounding the holding bracket receiver 59 is formed, and screw holes 67c and 67d are provided above and below the index unit upright portion 67a. The mounting holes 69 are spaced at a central angle of 45 ° over the circumference of a circle centered on the center line of the cylindrical body 69.
b is formed, and in a state where the flange 69a of the work supporting cylinder 69 is in contact with the surface of the index unit standing section 67a facing the tool supporting stand 52, any one of the mounting holes 69b of the work supporting cylinder 69 is formed. The positioning pin 70 and the fixing bolt 71 penetrating through the screw holes 67c and 67d of the index unit upright portion 67a are detachably screwed.

Further, the stub shaft sleeve 2, which is a workpiece, is fitted in the cylindrical space of the work support cylinder 69, and a lid 72 is applied to the tip of the work support cylinder 69, and penetrates the lid 72. The stub shaft sleeve 2 is firmly attached to the work support cylinder 69 by a mounting bolt 73 screwed to the work support cylinder 69.

Further, a driving unit 74 is disposed above the holder receiving support stand 53, and the driving unit 74
Is a motor 75 whose rotation axis is directed vertically, and a transmission 77 connected to the motor 75 via a transmission mechanism 76 such as a belt.
And a universal joint 78 connecting the output shaft 77a of the transmission 77 and the input shaft 46 of the forming tool 30.

Since the embodiment shown in FIGS. 3 to 9 is constructed as described above, the stub shaft sleeve 2 is fitted into the cylindrical space of the work supporting cylinder 69 and then the cover 72 is attached by the mounting bolt 73. Is attached to the tip end surface of the work supporting cylinder 69, the stub shaft sleeve 2 is attached to the index unit 67, and the forming tool is attached to the holder slider unit 55.
When the air cylinder 56 is extended after the attachment of the stub shaft sleeve 2, the receiving piece 36 of the forming tool 30 is fitted into the hole 59b of the holding bracket receiver 59, and the rotary blade 31 of the forming tool 30 is attached to the cylinder of the stub shaft sleeve 2. It is inserted into the inner peripheral surface 2a.

Then, the receiving piece 36 of the forming tool 30 is firmly fixed to the holding bracket receiver 59 with the tightening bolt 60, and the lower end of the universal joint 78 is connected to the input shaft 46 of the forming tool 30. Is started, the rotary blade 31 of the forming tool 30 is driven to rotate.

Next, the work back-and-forth reciprocating movement drive unit 64 of the work support piece 62 is operated to move the work front-rear slider 63 forward or backward to bring the cylindrical inner peripheral surface 23 of the stub shaft sleeve 2 closer to the rotary blade 31. At the same time, the work left and right reciprocating drive 66
Is moved to the left or right to position the rotary blade 31 at a position where the axial grooves 14 and 15 are to be formed on the cylindrical inner peripheral surface 23 of the stub shaft sleeve 2, and the cylindrical inner peripheral surface 2 a of the stub shaft sleeve 2 is Then, the forming process of one of the required axial grooves 14 and 15 is started.

After the stub shaft sleeve 2 is moved by moving the work supporting cylinder 69 by a stroke necessary to form the groove lengths (about 17 mm) of the axial grooves 14 and 15 of the stub shaft sleeve 2, By reversing the reciprocating drive 64 and moving the work front and rear slider 63 backward or forward, and then reversing the work left and right reciprocating drive 66 to move the work left and right slider 65 to the right or left, The cutting of the axial grooves 14 and 15 is performed at a diameter position opposed to the axial grooves 14 and 15 which have been cut.

By circulating the stub shaft sleeve 2 along a rectangular locus in a horizontal plane as described above, one of the required axial grooves 14 and 15 is formed in the cylindrical inner peripheral surface 2a of the stub shaft sleeve 2. Two articles can be formed.

Next, the upright portion 67a of the index unit 67
Pull out the positioning pin 70 and the fixing bolt 71 screwed to, rotate the work support cylinder 69 by 45 °, and index unit
After reattaching to the upright portion 67a of the 67, the above operation is performed, and if such operation is performed four times, eight axial grooves 14 and 15 are formed in the cylindrical inner peripheral surface 23 of the stub shaft sleeve 2. be able to. Therefore, it is enough to make the stub shaft sleeve 2 reciprocate four times to form the eight axial grooves 14 and 15, and the time required for forming the grooves can be greatly reduced.

The forming tool 30 includes a holder slider unit 55
And the holding bracket receiver 59, the rotating blade 31 is pivotally supported via the output shaft 49 by the wide side plates 34, 35 in the direction in which the cutting reaction force of the rotating blade 31 is received. Even if 31 receives a relatively large cutting reaction force, the forming tool 30
Does not deform to the left, and the required axial grooves 14 and 15 can be formed with high precision.

The rotating surface of the rotary blade 31 and the rotating surfaces of the input gears 42, the intermediate gears 43, 44, and the output gear 45 of the gear train 41 are vertically displaced from each other, and the rotary blade 31 is positioned below the gear train 41. As a result, the chips cut by the rotary blade 31 hardly reach the gear train 41, and the wear of the gear train 41 due to the chips is small.

Further, since the rotary blade 31 is held in the side plates 34 and 35 whose spacing is regulated by the spacers 33 with a very small gap that does not cause rotational friction, the axial grooves 14 and 35 are provided. The width accuracy of the 15 side edges can be kept at an extremely high level.

Further, the blade holder 32 of the forming tool 30 is composed of the spacer 33 and the side plates 34 and 35 and can be easily disassembled.
The exchange of 41 can be done very easily.

Furthermore, since the rotational force of the motor 75 can be directly transmitted to the rotary blade 31 via the transmission mechanism 76, the transmission 77, the universal joint 78, the input shaft 46 and the gear train 41, the axial grooves 14, 15 can be cut, the required cutting time can be shortened and the cutting efficiency can be improved.

In the above-described embodiment, the cylindrical stub shaft sleeve 2 is described as a cylindrical hollow body. However, the inner peripheral surface of the cylindrical hollow body is not a cylindrical surface but a rotating body surface such as an oblong body surface (rugby ball). However, if the operating trajectory of the rotary blade 31 is made to follow this ellipse, a groove having a predetermined depth can be formed.

In the above embodiment, the number of the axial grooves 14 and 15 is four each, that is, a total of eight. However, when the number of these axial grooves is, for example, an odd number of five, the rotary blade which is driven to rotate is used. The stub shaft sleeve 2 is moved forward in the axial direction while pushing the stub shaft sleeve 31 into the cylindrical inner peripheral surface 2a of the stub shaft sleeve 2 to a predetermined depth.
The stub shaft sleeve 2 is rotated by 36 ° around one of the axes of the stub shaft sleeve 2, and the stub shaft sleeve 2 is moved backward in the direction opposite to the forward movement direction while pushing the rotary blade 31 in the direction opposite to the previous pushing direction. Is repeated, it is only necessary to make the stub shaft sleeve 2 make one reciprocating movement of two reciprocations, and the number of reciprocating movements of the stub shaft sleeve 2 can be substantially reduced by half.

[0046]

As described above, according to the present invention, the cutting tool is inserted into the hollow space inside the cylindrical hollow body, and the rotary blade is positioned adjacent to the inner peripheral surface of the cylindrical hollow body. Since both ends of the holder can be supported, the rotary blade can be reliably held at a required position against the rotary blade cutting reaction force, and a required axial groove can be accurately formed.

In the present invention, since the rotary blade is positioned and supported in a substantially central space of the thickness of the holder, a cutting reaction force is applied to the blade holder via the rotary blade. Also, no torsional force acts on the blade holder, the rotary blade can be stably supported, and both side surfaces and the bottom surface of the axial groove formed on the inner peripheral surface of the cylindrical hollow body are not twisted. It can be formed on a highly accurate surface.

Furthermore, since the rotating surface of the rotary blade and the arrangement surface of the gear train are not the same surface, the chips cut by the rotary blade hardly reach the teeth of the gear train, and wear of the gear train is prevented. Is blocked.

Further, in the present invention, the width of the pivotal support portion of the blade holder for pivotally supporting the rotary blade having a diameter capable of being freely and removably fitted into the hollow space of the cylindrical hollow body is equal to the diameter of the rotary blade. Since the size is set to be slightly smaller than that, the groove parallel to the axial direction can be formed regardless of the size of the hollow space of the cylindrical hollow body, particularly the cylindrical hollow body. Even when the inner diameter of the body is small, the axial groove can be effectively formed, and even when the inner diameter of the cylindrical hollow body is large, it is effective when the axial groove is longer than this inner diameter. It is.

Further, by using the apparatus for forming a circumferential groove in a cylindrical hollow body of the present invention, the cylindrical hollow body and the tool for forming a circumferential groove in the cylindrical hollow body are relatively firmly supported while each is firmly supported. By moving, the axial groove of a required length and depth can be efficiently and reliably formed on the inner peripheral surface of the cylindrical hollow body.

Further, according to the present invention, since the power is transmitted from the input shaft to the rotary blade via the gear train, the rotary blade can be rotated with a large driving force, and the cutting time is shortened to increase productivity. Can be improved.

Further, by using the method for forming a circumferential groove in a cylindrical hollow body of the present invention, an axial groove can be formed very easily only at the center of the cylindrical hollow body while leaving both ends thereof.

Further, by applying the method for forming a circumferential groove in a cylindrical hollow body of the present invention, two axial grooves can be simultaneously formed at opposite diameter positions on the inner circumferential surface of the cylindrical hollow body. When the number of the axial grooves is even, the time required for forming the grooves can be reduced by half.

Further, in the present invention, when the number of the axial grooves formed on the peripheral surface of the cylindrical hollow body is an odd number, after forming one axial groove in the forward movement of a predetermined stroke, the groove of the axial groove is formed. After rotating the hollow cylindrical body about the axis of the hollow cylindrical body by an angle obtained by dividing 360 ° by a value twice as large as the number, the second axial groove is formed by the backward movement of a predetermined stroke. If this is repeated, the number of reciprocations of the hollow cylindrical body or the forming tool can be substantially reduced by half, and the time required for cutting can also be shortened and the productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a front view of a rotary servo valve incorporating a stub shaft sleeve as an example of a cylindrical hollow body to which the present invention is applied.

FIG. 2 is a vertical sectional side view thereof.

FIG. 3 is a plan view illustrating an embodiment of a tool for forming a circumferential groove in a cylindrical hollow body according to the present invention.

FIG. 4 is a vertical sectional side view thereof.

FIG. 5 is an exploded perspective view thereof.

FIG. 6 is a front view illustrating one embodiment of a cylindrical hollow body peripheral groove forming apparatus of the present invention.

FIG. 7 is a cross-sectional view taken along line VII-VII of FIG.

FIG. 8 is an enlarged cross-sectional view of an essential part taken along line VIII-VIII in FIG.

FIG. 9 is a longitudinal sectional view taken along line IX-IX of FIG.

FIG. 10 is a vertical sectional side view of a conventional stub shaft sleeve.

FIG. 11 is a transverse sectional view cut along the line XI-XI of FIG. 10;

[Explanation of symbols]

0: rotary servo valve, 1: valve housing, 2
... Stub shaft sleeve, 3 ... Stub shaft, 4 ...
Oil supply port, 5: Oil discharge port, 6: Left cylinder port, 7: Right cylinder port, 8: Circumferential oil supply groove, 9 ...
Circumferential left cylinder groove, 10 ... Circumferential right cylinder groove, 11
... refueling passage, 12 ... left cylinder passage, 13 ... right cylinder passage, 14, 15, 16, 17 ... axial groove, 18 ... center hole, 19, 20
... Drainage passage, 21 ... Rack, 22 ... Pinion, 30 ... Forming tool, 31 ... Rotary blade, 32 ... Tool holder, 33 ... Spacer,
34, 35 ... side plate, 36 ... receiving piece, 37 ... knock pin,
38 ... bolt, 39 ... knock pin, 40 ... bolt, 41 ... gear train, 42 ... input gear, 43 ... intermediate gear, 44 ... intermediate gear, 45 ...
Output gear, 46… Input shaft, 47, 48… Intermediate shaft, 49… Output shaft,
50 ... molding equipment, 51 ... base, 52 ... tool support stand, 53 ...
Holder support stand, 54: Slide rail, 55: Holder slider unit, 56: Air cylinder, 57: Positioning pin, 58: Tightening bolt, 59: Holder receiver, 60: Tightening bolt, 61: Mounting bolt, 62: Work support Table, 63 ... Work front and back slider, 64 ... Work back and forth reciprocating drive, 65
… Work left and right slider, 66… Work left and right reciprocating drive unit. 67… Index unit, 68… Mounting bolt, 69
... Work support cylinder, 70 ... Positioning pin, 71 ... Fixing bolt, 72 ... Lid, 73 ... Mounting bolt, 74 ... Drive unit, 75
... motor, 76 ... transmission, 77 ... transmission, 78 ... universal joint.

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B23C 3/34

Claims (3)

(57) [Claims] 1. A forming tool for forming a groove parallel to the axial direction at a substantially central portion in the axial direction of a peripheral surface of a cylindrical hollow body, the forming tool comprising a hollow space in the cylindrical hollow body. A rotary blade having a diameter capable of loosely fitting into and removably attached to the rotary blade and a width capable of forming the groove, a width of a rotary blade pivotal support portion of the blade holder being smaller than a diameter of the rotary blade, and crossing the blade holder A blade holder having a cross-sectional shape and dimensions whose surface shape and dimensions can be freely and removably fitted into the hollow space in the cylindrical hollow body in the longitudinal direction, and a longitudinal direction of the blade holder. And a gear train for transmitting power to the rotary blade by arranging a plurality of gears across the rotary blade. Rotatable about the axis perpendicular to the axis of the hollow body A space that can be pivotally supported is formed, and a space in which the gear train can be arranged is formed on one outer side in the thickness direction of the blade holder, and an input shaft is provided at an input end gear of the gear train. A tool for forming a circumferential groove in a cylindrical hollow body, wherein the rotary blade is integrally connected to an output end gear of the gear train. 2. A molding device for forming a groove parallel to an axial direction at a substantially central portion in an axial direction of a peripheral surface of a cylindrical hollow body,
2. The forming apparatus according to claim 1, wherein the peripheral groove forming tool has a cylindrical hollow body, tool support means for supporting both ends of the forming tool, and the rotary blade is connected to an input shaft of the forming tool to rotationally drive the rotary blade. Blade driving means for causing, a cylindrical hollow body supporting means for supporting the cylindrical hollow body which is a workpiece, and one or both of the tool supporting means and the cylindrical hollow body supporting means, wherein the groove is relatively formed. And a moving means for moving the groove in a direction parallel to the groove and in a depth direction of the groove. 3. A molding method for forming a groove parallel to the axial direction at a substantially central portion in an axial direction of a peripheral surface of a cylindrical hollow body, wherein a center axis of a rotary blade is arranged in an axial direction of the cylindrical hollow body. In a state in which the rotary blade is directed at a right angle, the rotary blade is made to enter the hollow space of the cylindrical hollow body, and while rotating the rotary blade, is pushed toward the inner peripheral surface of the cylindrical hollow body by a predetermined depth. After cutting one groove by moving forward a predetermined stroke in the axial direction of the cylindrical hollow body, the cylindrical hollow body is pressed while pushing a predetermined depth toward a diameter portion of the inner peripheral surface facing the cut groove. A method for forming a circumferential groove in a cylindrical hollow body, wherein a groove parallel to the axial direction of the cylindrical hollow body is formed by reciprocating the predetermined stroke in the axial direction and cutting the other groove.