JPH054110A - Cylindrical hollow body inner wall groove shaping tool, shaping device and method therefor - Google Patents

Abstract

PURPOSE:To form a groove parallel to the axial direction on the inner wall surface of a cylindrical hollow body by bringing a rotary cutter into contact with the inner wall surface of the cylindrical hollow body and shifting a cutter holding tool in the longitudinal direction. CONSTITUTION:The receiving piece 36 of a shaping tool 30 is fixed with a holding metal fitting receiver, and the lower edge of a universal joint 78 is joined with an input shaft 46, and a motor is started, and then a rotary cutter 31 is revolution-drive. Then, the rotary cutter 31 positioned at a place for forming a groove in the axial direction on the cylindrical inner peripheral surface of a stub shaft sleeve by operating a longitudinal reciprocating movement driving part for a work and the lateral reciprocating movement driving part for the work, and one shaping work for the groove in a prescribed axial direction is started on the cylindrical inner peripheral surface of the stub shaft sleeve. After the stub shaft sleeve is shifted by the stroke necessary for forming the groove in the axial direction, the longitudinal reciprocating movement driving part for the work and the lateral reciprocating movement driving part for the work are driven reversely, and the groove in the axial direction is cut at the diameter position which is opposed to a cut groove in the axial direction.

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 (a cylindrical hollow body in the present specification means that a straight line or a curve at a predetermined distance from the central axis is rotated about the central axis. A molding tool, a molding apparatus and a molding method for forming a groove parallel to the axial direction of the cylindrical hollow body on the inner peripheral surface of Is.

[0002]

BACKGROUND OF THE INVENTION A plurality of grooves parallel to the axial direction are formed at a substantially central portion of the circumferential surface of a cylindrical body at equal intervals over the circumferential direction. For example, a rotary control valve of a power steering mechanism is provided. That is, there is a stub shaft sleeve incorporated into the rotary servo valve.

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 and a rotary servo valve, and the rotary servo valve is configured as shown in FIGS. 1 and 2.

The rotary servo valve 0 has a valve housing 1, a stub shaft sleeve 2 that is oil-tightly and rotatably fitted in the valve housing 1, and is rotatable on an inner peripheral surface of the stub shaft sleeve 2. The valve housing 1 is provided with an oil supply port 4 and an oil discharge port 5 which are respectively connected to a discharge port and a suction port of a hydraulic pump (not shown). A left cylinder port 6 and a right cylinder port 7 which communicate with both the left and right cylinder chambers are formed.

On the outer peripheral surface of the stub shaft sleeve 2, a circumferential circumferential oil supply groove 8 communicating with the oil supply port 4 is formed, and a peripheral oil communication groove 8 communicating with the left cylinder port 6 and the right cylinder port 7 is formed. The circumferential left cylinder groove 9 and the circumferential right cylinder groove 10 are circumferential oil supply grooves 8.
Are formed on both sides in the axial direction. Further, the stub shaft sleeve 2 is provided with four oil supply passages 11 which are oriented toward the central axis thereof and whose outer ends are opened to 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 of the stub shaft sleeve 2 at an angle of 22.5 ° centering on the central axis of the stub shaft sleeve 2 and oriented 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 and right cylinder passage 13 are provided.
And the center of the groove coincides with the axial direction of the stub shaft sleeve 2, and four axial grooves 14 and 15 are formed alternately, that is, four grooves in total, 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 each axial groove 15.

Furthermore, on the outer peripheral surface of the stub shaft 3, axial grooves 16 and 17 having a width equal to the width of the portion of the stub shaft sleeve 2 sandwiched by the axial grooves 14 and 15 are alternately arranged in the circumferential direction. It is formed at intervals. An oil drain passage 19 that connects the central hole 18 of the stub shaft 3 and the axial groove 17 is formed, and the central 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 which meshes with a rack 21 which is integral with a piston of a power cylinder (not shown) to rotate the steering wheel. 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 either one of the axial grooves 14 and 15, for example, the axial groove 14, and the circumference from the oil supply port 4 is reached. The pressure oil that has flowed into the axial groove 16 via the directional oil supply groove 8 and the oil supply passage 11 is shown in the figure via the axial groove 14 via the left cylinder passage 12, the circumferential left cylinder groove 9, and the left cylinder port 6. In the left cylinder chamber of the unpowered cylinder, the piston moves to the right and the wheels turn in the required direction. The description of the oil discharge state in the right cylinder chamber is omitted.

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 has 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 hydraulic oil to the cylinder is stopped.

In the above rotary servo valve 0, in order for the power steering mechanism to operate smoothly and appropriately, the axial grooves 14 and 15 of the inner peripheral surface 2a of the stub shaft sleeve 2 and the outer peripheral surface of the stub shaft 3 are required. In order to maintain the center position accuracy of the axial grooves 16 and 17 and the width accuracy thereof to a predetermined level, the axial grooves 14 and 15 and the axial grooves 16 and 17 are
Need to be processed.

When the axial grooves 16 and 17 are formed in the stub shaft 3, since the axial grooves 16 and 17 are exposed on the outer peripheral surface of the stub shaft 3, the stub is relatively easy to machine. When forming the axial grooves 14 and 15 in the shaft sleeve 2, the axial grooves 14 and 15 are formed in the stub shaft sleeve 2.
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, its machining is difficult as described below.

[0012]

2. Description of the Related Art Conventionally, in order to overcome such difficulties, as shown in FIGS. 10 to 11, an inner peripheral surface 02 of a hollow cylinder 01 has a full axial length. 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 rings 05 for closing both ends of the vertical groove 03 are fitted into the hole 04. By attaching the vertical groove 03 to the inner peripheral surface 02 of the hollow cylinder in the substantially central portion in the axial direction.
There was a split stub shaft sleeve that made up the.

In this rotary body, the cross-sectional shape of the vertical groove 03 can be freely formed into a desired shape, but in order to prevent oil leakage of the vertical groove 03, the machining accuracy of the hole 04 and the ring 05 must be high. It is unavoidable that the number of parts and the number of processing steps increase and the cost increases.

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 a high groove width accuracy, and the blade life is short and the machining time is long. Productivity is low.

Further, when the slotter is used, the mechanism becomes complicated and the cost becomes high, skill and time are required for the dimension adjustment when exchanging the blade, and the machining allowance per time is small, so that the machining time becomes long and the production is also possible. It is not very popular.

Furthermore, as described in Japanese Patent Publication No. 1-48090, in which an axial groove is formed on the inner peripheral surface of a hollow cylinder by forging, the groove edge can be formed into a sharp shape. However, there is a drawback that the accuracy of the groove width is greatly reduced when the die is worn.

[0017]

SUMMARY OF THE INVENTION The present invention relates to an invention for forming an axial groove on a peripheral surface of a cylindrical hollow body, which solves the above problems, and relates to a substantially central portion of the peripheral surface of the cylindrical hollow body in the axial direction. A forming tool for forming a groove parallel to the axial direction in the portion, the forming tool forming a diameter and the groove that can be loosely fitted into the hollow space in the cylindrical hollow body. A rotary blade having a width that allows the rotary blade of the blade holder to have a width smaller than the diameter of the rotary blade, and the cross-sectional shape and dimensions of the blade holder in the longitudinal direction of the cylindrical hollow body. Power is applied to the rotary blade by arranging a blade holder that is set to have a cross-sectional shape and dimensions that can be loosely fitted in and out of the hollow space and a plurality of gears arranged in the longitudinal direction of the blade holder. A rotary blade of the blade holder, which is composed of a gear train for transmission. A space is formed in the central portion in the thickness direction of the pivot portion so that the rotary blade can be sandwiched and rotatably supported around the axis of the cylindrical hollow body as a central axis, and the blade holder can be held. A space in which the gear trains can be arranged is formed on one outer side in the thickness direction of the tool, the input shaft is integrally coupled to the input end gear of the gear train, and the output end gear of the gear train is 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 open end of the hollow space, and the lengthwise direction of the blade holder is changed. While being oriented parallel to the axial direction of the cylindrical hollow body, the rotary blade is applied to a required portion of the inner peripheral surface of the cylindrical hollow body to form a groove, and the input shaft is driven to rotate. A groove parallel to the axial direction can be formed on the peripheral surface of the hollow cylindrical body by pushing the tool holder to a predetermined depth and moving the tool holder along its longitudinal direction.

The present invention is also a molding apparatus for forming a groove parallel to the axial direction substantially central portion of the circumferential surface of a cylindrical hollow body, the molding apparatus according to claim 1. A cylindrical hollow body circumferential groove forming tool, a tool supporting means for supporting both ends of the forming tool, a blade driving means connected to an input shaft of the forming tool to drive the rotary blade to rotate, and a workpiece. A cylindrical hollow body supporting means for supporting the cylindrical hollow body, and a direction in which one or both of the tool supporting means and the cylindrical hollow body supporting means are relatively parallel to the groove and a depth direction of the groove. It is characterized by comprising a moving means for moving the inner peripheral surface of the hollow cylindrical body in the axial direction by using such a molding device. it can.

Furthermore, the present invention is a molding method for forming a groove parallel to the axial direction at a substantially central portion of the circumferential surface of a cylindrical hollow body in the axial direction, the rotary blade being in the axial direction of the cylindrical hollow body. In a state where the central axis of the cylindrical hollow body is oriented 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, a predetermined depth toward the inner peripheral surface of the cylindrical hollow body. After pushing forward a predetermined stroke in the axial direction of the hollow cylindrical body to cut one groove, the hollow cylindrical body is pushed to a predetermined depth toward the diameter portion of the inner peripheral surface facing the cutting groove. A groove parallel to the axial direction of the cylindrical hollow body is formed by reciprocating the predetermined stroke in the axial direction of the hollow body and cutting the other groove. By using it, the cylindrical hollow can be formed by 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]

EXAMPLE An example 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 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 cylinder inner peripheral surface 2a of the stub shaft sleeve 2 is about 22 mm. The axial grooves 14 and 15 parallel to the axial direction of the stub shaft sleeve 2 have a groove width of about 4.5 mm, a depth of about 1 mm, and a length of about 17 mm.
mm. The forming tool 30 is composed of a rotary blade 31, a blade holder 32, and a gear train 41. The rotary blade 31 has a tooth width of about 4.5 mm and a diameter of about 20 mm.

Further, the blade holder 32 is a spacer 33 having a thickness very slightly (about 10 μm) thicker than the tooth width of the rotary blade 31.
4.3mm thick side plates 34 and 35 for sandwiching the spacer 33 from both sides, the tip portion 36a has the same thickness as the spacer 33, and the base portion 36b has the spacer 33, the side plate 34, It consists of a receiving piece 36 set to 13.1 mm, which is the sum of the thicknesses of 35, and the spacer 33, side plates 34, 35 are fixed in their longitudinal relative positions by knock pins 37 passing through them. Left side plate
It is designed to be integrally connected by two bolts 38 which penetrate through the side plates 34 and 35 and are screwed to the side plate 35. Moreover, the side plates 34 and 35 and the receiving piece 36 are combined with each other. , 35, and the tip 36 of the receiving piece 36.
While the relative position is fixed by two knock pins 39 penetrating a and a, they are integrally coupled by two bolts 38 threaded through the side plate 34 and spacer 33 and screwed to the side plate 35. Moreover, the side plates 34, 35 and the receiving piece 36 are relatively arranged 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 spacer 33 are integrally coupled by a bolt 40 penetrating the tip portions 34a, 33a of the spacer 33 and screwed to the tip portion 35a of the side plate 35. .

Further, the gear train 41 includes an input gear 42 and an intermediate gear.
43, 44 and an output gear 45, and the input gear 42 includes a spacer 33, side plates 34, 35 having respective tip ends 33a, 34a, 35.
The intermediate gear 43, 44 is integrally fitted to the input shaft 46 rotatably passing through the a, and the intermediate gears 43, 44 are fixed by penetrating the spacers 33, the tip portions 33a, 34a, 35a of the side plates 34, 35.
7 and 48 are rotatably fitted, and the output gear 45 and the rotary cutting tool 31 are integrally fitted to the output shaft 49 that rotatably penetrates the tip portions 34a and 35a of the side plates 34 and 35. When a rotational force is applied to 46, the rotary blade 31 is rotationally driven.

However, the side plate 34 has a gear train.
Notch 34 such that each input gear 42, intermediate gears 43, 44, and output gear 45 of 41 do not significantly project to the surface of 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 further, the intermediate shaft 48 is formed with a notch 48a through which the rotary blade 31 can rotate.

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

In the molding apparatus 50, a tool support stand 52 and a holder support stand 53 are vertically erected integrally on a base 51, and two slide rails are provided above the tool support stand 52.
54 is laid, and the holder slider unit 55 is slidably mounted on the slide rail 54, and the tool support stand
The retainer slider unit 55 is integrally attached to the tip of the piston rod 56a of the air cylinder 56 attached to the 52, and the retainer slider unit 55 can reciprocate left and right in response to expansion and contraction of the piston 56a of the air cylinder 56. It is like this.

Further, 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 the blade holder.
A tightening bolt 58 that can fix 32 is screwed.

Further, in the holder support stand 53,
A retainer receiver 59 is provided which is capable of fitting the receiving piece 36 of the blade holder 32 in a removable manner and which can hold the receiving piece 36 with a tightening bolt 60.
A cutting oil passage 59a communicating with the cutting oil discharge hole 36b provided in the receiving piece 36 of the blade holder 32 is formed.
The mounting bolts 61 are detachably mounted on the holder support stand 53.

Further, a work support base 62 is disposed between the tool support stand 52 and the holder support stand 53, and a work front / rear slider 63 is attached to the work support base 62 so as to be slidable back and forth. 4mm back and forth
A work back-and-forth reciprocating drive unit 64 that reciprocates is provided, and a work left-right slider 65 is attached to the work front-rear slider 63 so that it can slide left and right, and a work left-right reciprocating drive that reciprocates the work left-right slider 65 about 15 mm left and right. A section 66 is provided.

An index unit 67 is removably mounted on the upper surface of the work left and right sliders 65 by means of mounting bolts 68, and an upright portion 67a of the index unit 67 has a space such that it can move back and forth by 5 mm or more with respect to the holding bracket receiver 59. Is formed, and a U-shaped space 67b surrounding the holding bracket receiver 59 is formed. Screw holes 67c and 67d are provided above and below the index unit upright portion 67a, and the workpiece support is provided on the flange portion 69a of the workpiece support cylinder 69. Mounting holes 69 are spaced at a central angle of 45 ° along the circumference of a circle centered on the center line of the cylinder 69.
b is formed, and the flange portion 69a of the work support cylinder 69 is in contact with the surface of the index unit upright portion 67a facing the tool support stand 52, any mounting hole 69b of the work support cylinder 69 is formed. The positioning pin 70 and the fixing bolt 71 penetrating therethrough are detachably screwed into the screw holes 67c and 67d of the index unit upright portion 67a.

Further, the stub shaft sleeve 2 as a workpiece is fitted into the cylindrical space of the work supporting cylinder 69, and the lid 72 is applied to the tip end of the work supporting cylinder 69 so as to penetrate the lid 72. The stub shaft sleeve 2 is firmly attached to the work supporting cylinder 69 by a mounting bolt 73 screwed to the work supporting cylinder 69.

Further, a drive unit 74 is arranged above the holder receiving and supporting stand 53, and the drive unit 74 is provided.
Is a motor 75 whose rotary shaft is oriented vertically and a transmission 77 connected to the motor 75 via a transmission mechanism 76 such as a belt.
And a universal joint 78 that connects 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 configured as described above, the stub shaft sleeve 2 is fitted in the cylindrical space of the work supporting cylinder 69 and then the lid 72 is fixed by the mounting bolt 73. Is attached to the front end surface of the work support cylinder 69, the stub shaft sleeve 2 is attached to the index unit 67, and the holder slider unit 55 is formed with a forming tool.
When the air cylinder 56 is extended after the 30 is mounted, the receiving piece 36 of the forming tool 30 is fitted into the hole 59b of the holding metal fitting receiving 59, and the rotary blade 31 of the forming tool 30 is a 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 to drive the motor 75 of the drive unit 74. When the tool is started, the rotary blade 31 of the molding tool 30 is rotationally driven.

Next, the work back-and-forth reciprocating motion drive unit 64 of the work support piece 62 is operated to move the work front-and-back 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 / right reciprocating drive unit 66 is operated to move the work left / right slider 65.
Is moved to the left or right to position the rotary cutting tool 31 at a position where the axial grooves 14, 15 should be formed in the cylindrical inner peripheral surface 23 of the stub shaft sleeve 2, and the cylindrical inner peripheral surface 2a of the stub shaft sleeve 2 is positioned. First, the forming process of either one of the required axial grooves 14 and 15 is started.

After moving the stub shaft sleeve 2 by moving the work supporting cylinder 69 by the stroke required to form the groove length (about 17 mm) of the axial grooves 14 and 15 of the stub shaft sleeve 2, the front and rear By reversing the reciprocating motion drive unit 64 to move the work front-rear slider 63 backward or forward, and then reversing the work left-right reciprocating drive unit 66 and moving the work left-right slider 65 to the right or left, The axial grooves 14 and 15 are cut at diameter positions opposite to the axial grooves 14 and 15 that have been cut.

By cyclically moving the stub shaft sleeve 2 along a rectangular locus in the horizontal plane in this way, one of the required axial grooves 14, 15 is formed on the cylindrical inner peripheral surface 2a of the stub shaft sleeve 2. Two lines can be formed.

Next, the standing portion 67a of the index unit 67.
Remove the positioning pin 70 and the fixing bolt 71 screwed to the
After reattaching to the upright portion 67a of 67, the above-mentioned work is performed, and when such work 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 sufficient to reciprocate the stub shaft sleeve 2 four times to form the eight grooves 14 and 15 in the axial direction, and the groove forming time can be greatly reduced.

The forming tool 30 is a holder slider unit 55.
Since the rotary blade 31 is pivotally supported via the output shaft 49 by the side plates 34 and 35 having a wide width in the direction of receiving the cutting reaction force of the rotary blade 31, the rotary blade 31 is pivotally supported by the output shaft 49. Even if 31 receives a relatively large cutting reaction force,
Does not deform to the left, and the required axial grooves 14 and 15 can be formed with high precision.

The rotation surface of the rotary blade 31 and the rotation 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. Therefore, 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 mutual spacing is regulated by the spacer 33 with a very small gap that does not cause rotational friction, the axial groove 14 and The width accuracy of the 15 side edges can be kept at an extremely high level.

Further, since 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 rotary blade 31 and the gear train.
41 can be exchanged very easily.

Moreover, 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, a large cutting force is applied to the axial groove 14, 15 can be cut, the cutting time can be shortened and the cutting efficiency can be improved.

In the above embodiment, the cylindrical stub shaft sleeve 2 was described as the cylindrical hollow body. However, the inner peripheral surface of the cylindrical hollow body is not a cylindrical surface but a surface of a rotating body such as an ellipsoidal surface (rugby ball). However, if the operation trajectory of the rotary blade 31 is set along this ellipse, it is possible to form a groove having a predetermined depth.

Further, in the above-mentioned embodiment, the axial grooves 14 and 15 are each 4 in total, that is, 8 in total, but when these axial grooves are, for example, an odd number of 5, the rotary blade which is rotationally driven. While pushing 31 into the cylindrical inner peripheral surface 2a of the stub shaft sleeve 2 by a predetermined depth, the stub shaft sleeve 2 is moved in the axial direction, and then the rotary blade 21 is separated from the cylindrical inner peripheral surface 2a.
The stub shaft sleeve 2 is rotated 36 ° in either direction about the axis of the stub shaft sleeve 2, and the stub shaft sleeve 2 is returned in the direction opposite to the forward direction while pushing the rotary blade 31 in the direction opposite to the previous pushing direction. However, the number of reciprocating movements of the stub shaft sleeve 2 can be substantially halved by merely moving the stub shaft sleeve 2 forward and backward twice.

[0046]

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

Further, in the present invention, since the rotary blade is positioned and pivotally 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. In addition, the blade holder does not have a twisting force, can stably support the rotary blade, 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 rotation surface of the rotary blade and the arrangement surface of the gear train are not the same surface, it is difficult for the chips cut by the rotary blade to reach the teeth of the gear train, and the wear of the gear train is reduced. Be blocked by.

Furthermore, in the present invention, the width of the pivotal support portion of the blade holder for pivotally supporting the rotary blade having a diameter that can be loosely fitted in 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, it is possible to form a groove parallel to the axial direction of the hollow space of the cylindrical hollow body regardless of the size thereof. Even if the inner diameter of the body is small, the axial groove can be effectively formed, and even if the inner diameter of the cylindrical hollow body is large, it is effective when the axial groove is longer than this inner diameter. Is.

Further, by using the cylindrical hollow body circumferential groove forming device of the present invention, the cylindrical hollow body and the cylindrical hollow body circumferential groove forming tool are firmly supported respectively, and both are relatively supported. By moving it, the axial groove having a required length and depth can be formed efficiently and reliably on the inner peripheral surface of the cylindrical hollow body.

Furthermore, in the present invention, since 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 time required for cutting can be shortened to greatly improve productivity. Can be improved.

Further, by using the method for forming the circumferential groove in the cylindrical hollow body of the present invention, it is possible to easily form the axial groove only in the central portion of the cylindrical hollow body leaving both ends.

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

Furthermore, in the present invention, when the axial groove formed on the peripheral surface of the cylindrical hollow body has an odd number of threads, one axial groove is formed by a forward stroke of a predetermined stroke and then the axial groove is formed. After rotating the hollow cylindrical body around the axis of the hollow cylindrical body by an angle obtained by dividing 360 ° by twice the number, a second stroke axial groove is formed by the backward movement of a predetermined stroke. By reversing this, the number of reciprocations of the hollow cylindrical body or the forming tool can be reduced to about half, and the required cutting time can be shortened and the productivity can be improved.

[Brief description of 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 showing an embodiment of the cylindrical hollow body circumferential groove forming tool of 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 showing an embodiment of the apparatus for forming a circumferential groove in a cylindrical hollow body of the present invention.

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

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

9 is a vertical cross-sectional view taken along line IX-IX in FIG.

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

11 is a transverse cross-sectional view cut along the line XI-XI in 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
... Oil supply passage, 12 ... Left cylinder passage, 13 ... Right cylinder passage, 14, 15, 16, 17 ... Axial groove, 18 ... Center hole, 19, 20
... Oil drain passage, 21 ... Rack, 22 ... Pinion, 30 ... Molding tool, 31 ... Rotating blade, 32 ... Blade holder, 33 ... Spacer,
34, 35 ... Side plate, 36 ... Receiving piece, 37 ... Dowel pin,
38 ... Bolts, 39 ... Dowel pins, 40 ... Bolts, 41 ... Gear trains, 42 ... Input gears, 43 ... Intermediate gears, 44 ... Intermediate gears, 45 ...
Output gear, 46 ... Input shaft, 47, 48 ... Intermediate shaft, 49 ... Output shaft,
50 ... Molding device, 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 ... Workpiece support Table, 63 ... Workpiece front / back slider, 64 ... Workpiece front / back reciprocating drive unit, 65
… Workpiece left and right slider, 66… Workpiece left and right reciprocating drive unit. 67… Index unit, 68… Mounting bolts, 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.

Claims (3)

[Claims] 1. A forming tool for forming a groove parallel to the axial direction at a substantially central portion of an outer 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 such that it can be loosely fitted into and removed from the blade and a width capable of forming the groove, and the width of the rotary blade pivot portion of the blade holder is smaller than the diameter of the rotary blade and traverses the blade holder. A blade holder whose surface shape and dimensions are set to have a cross-sectional shape and dimensions that can be loosely fitted in the hollow space of the cylindrical hollow body over the longitudinal direction thereof, and the longitudinal direction of the blade holder And a gear train that transmits power to the rotary blade by arranging a plurality of gears over the rotary blade, and the rotary blade is clamped in the central portion in the thickness direction of the rotary blade pivot portion of the blade holder to form the cylindrical shape. Freely rotatable about the axis perpendicular to the axis of the hollow body A space in which the gear train can be arranged is formed in a thickness direction outer side portion of the blade holder while a space that can be pivotally formed is formed, and an input shaft is provided in an input end gear of the gear train. A cylindrical hollow body circumferential groove forming tool, characterized in that 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 center of a peripheral surface of a tubular hollow body, the molding device comprising:
The forming apparatus is connected to the cylindrical hollow body circumferential groove forming tool according to claim 1, tool supporting means for supporting both ends of the forming tool, and an input shaft of the forming tool to drive the rotary blade to rotate. The tool driving means for causing, the 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 relatively to the groove. And a moving means for moving the groove in a direction parallel to the groove and in the depth direction of the groove. 3. A molding method for forming a groove parallel to the axial direction at a substantially central portion of a peripheral surface of a cylindrical hollow body in the axial direction, the central axis of a rotary blade relative to the axial direction of the cylindrical hollow body. In a state of being oriented at a right angle, the rotary blade is made to enter the hollow space of the cylindrical hollow body, and while being driven to rotate, the rotary blade is pushed toward the inner peripheral surface of the cylindrical hollow body by a predetermined depth. After moving one groove forward by a predetermined stroke in the axial direction of the cylindrical hollow body to cut one groove, the cylindrical hollow body of the cylindrical hollow body is pushed toward the diameter portion of the inner peripheral surface facing the cutting groove by a predetermined depth. A cylindrical hollow body circumferential groove forming method, 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.