JPH0240446B2 - ENTONAIMENNONAGAKOSETSUSAKUSOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for cutting long grooves on the inner surface of a cylinder, and more particularly, an apparatus for cutting a plurality of long grooves on the inner circumferential surface of a cylinder, each of which is closed at both ends, parallel to the cylindrical center and to the same depth. Regarding.

As shown in Fig. 1, a cylinder (hereinafter sometimes referred to as a workpiece) 1 is generally used as an automobile part.
There is a part 3 formed by forming a plurality of long grooves (hereinafter simply referred to as long grooves) 2, which are closed at both ends, on the inner circumferential surface 1A of the cylinder, parallel to the cylindrical center, and at the same depth.

Conventionally, when manufacturing a component 3 as shown in FIG. 1, as shown in FIG.
After broaching the cylinder 1', rings 4, 4 are press-fitted into both ends of the cylinder 1' to close the openings at both ends of the long groove 2', or as shown in Fig. 3, There is a method of cutting the long grooves 2 one by one on the inner peripheral surface 1A of the workpiece 1 with a cutter 5, and a method of cutting the long grooves 2 on the inner peripheral surface 1A of the workpiece 1 with a key slotter type cutter 6 as shown in FIG.
A method is used in which the material is cut one by one while being indexed.

However, in the conventional cutting method shown in Fig. 2, the number of assembly steps increases due to the increase in the number of parts, and when this processed product is used as a valve part, the contact surface of the ring In the method shown in FIGS. 3 and 4, in which leakage occurs from the groove, the long groove indexing mechanism is complicated, and
Machining efficiency decreases due to machining one long groove at a time.
There were other drawbacks.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art and to provide a long groove cutting device on the inner surface of a cylindrical surface that can efficiently cut a plurality of long grooves with both ends closed on the inner circumferential surface of a workpiece.

The present invention is characterized in that by making a so-called grinding motion of the star-shaped cutter relative to the workpiece, cutting is performed in parallel while automatically determining the required number of long grooves in the workpiece. shall be.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 5 shows an embodiment of the present invention,
At one side of the workpiece 1, which is fixedly held by a clamp device (not shown), a table 11 is placed on a bed (not shown) so as to be able to reciprocate in parallel with the axis of the workpiece 1. It is designed to be reciprocated and slidably driven by a pressure cylinder 12 or the like. On the table 11 is a bearing block 13.
A bearing block 13 rotatably supports a large diameter main shaft 14. This main shaft 14 is configured such that its axis 14C can coincide with the extension line of the cylindrical center 1C of the workpiece 1. Main shaft 1
4, a subshaft 15 is rotatably supported at an angle to the axis 14C, and the axis 15C of the subshaft 15 is inclined to the axis 14C.
4C, that is, can intersect with the cylindrical center 1C of the workpiece 1 at an inclination angle α. This sub-shaft 15 is formed into a cylindrical shape, and a cutter shaft 16 is slidably fitted onto a cylinder core 15C within this cylinder. , is prevented from rotating by suitable means.

At the end of the knife shaft 16 on the side where the knife shaft 16 intersects with the extension line of the axis 14C of the main shaft 14, a star-shaped knife 18 as shown in FIG. 6 is fixed at right angles to the axis 15C. . This star-shaped cutter 18 has a predetermined number of cutting blades 19 protruding equiangularly and radially on its outer circumference, and the outer diameter of the group of cutting blades 19 is set to be slightly smaller than the inner diameter of the workpiece 1. . The cutting blade 19 is formed in a shape almost similar to the tooth shape of a gear, its tooth width is slightly smaller than the width of the long groove 2 to be cut into the workpiece 1, and its tooth height is slightly larger than the depth of the long groove 2. , are set respectively. The number n of the 19 groups of cutting blades is about 1 to 2 less than the number N of the 2 groups of long grooves to be cut, that is, N-n≒
1 to 2, and in this embodiment, the number of long grooves in group 2 is 8, while the number of cutting blades in 19 groups is 6.
It is set to . In addition, adjacent cutting edges 1
The dimension between the intersections of the respective pitch circles 9 and 19 and the center line of the cutting edge 19 (hereinafter referred to as the arrangement circumferential pitch) is made to be equal to the arrangement circumferential pitch of the adjacent long grooves 2 and 2. It is set.

A stand 20 is installed at a substantially right angle on one side of the bearing block 13 on the table 11 on the side opposite to the workpiece 1, and a support shaft 21 is mounted on the upper part of the stand 20 on the side of the main shaft 14. It is fixed on the axis 14C toward. Support shaft 21
A sun gear 22 consisting of a bevel gear is located at the tip of the axis 1.
It is fixed at right angles to 4C. On the other hand, the secondary shaft 1
A planetary gear 23 consisting of a bevel gear is integrally formed on the outer periphery of the blade 5 at the end opposite to the cutter 18 .
2, so that they can rotate and revolve around each other.

The end of the cutter shaft 16 opposite to the end to which the cutter 18 is attached protrudes from the end of the subshaft 15, and a male threaded portion 24 is formed at this protruding end. A feed female threaded shaft 25 rotatably supported by the main shaft 14 is screwed into this male threaded portion 24, and this female threaded shaft 25 slidably abuts on the end surface of the planetary gear 23 of the subshaft 15, and is attached to the main shaft 14. The movement in the axial direction is restricted by abutting the opposite end on a part of the shaft 14. A driven gear 26 made of a bevel gear is integrally formed on the outer periphery of the female feed screw shaft 25 at the end on the planetary gear 23 side. On the other hand, a drive shaft 27 is rotatably fitted to the support shaft 21, and the sun gear 2 on the outer periphery of this shaft 27
A driving gear 28 is integrally formed at the second end.
This gear 28 is the driven gear 26 of the driven gear 26.
They are meshed to allow the revolution of the two. A worm wheel 29 is integrally formed at the other end of the drive shaft 27, and this worm wheel 29 meshes with a worm 30. The worm 30 has a box 31 fixed to the top of the stand 20.
This box 31 is rotatably supported on the
It is designed to be rotationally driven by a motor 32 housed within the housing and capable of forward and reverse rotation. Further, this box 31 rotatably supports the drive shaft 27 from the outside. and the male threaded portion 24,
The feed female screw shaft 25, the main and slave gears 28, 26, the drive shaft 27, the worm wheel 29, the worm 30, and the motor 32 are examples of driving means for reciprocating and sliding the cutter shaft 16 in the axial direction of the sub-shaft 15. It consists of

A motor 33 as a rotational drive source is installed outside the bearing block 13, and the rotational force of the motor 33 is applied to a drive pulley 34 protruding from the motor output shaft, a belt 35, and the main shaft 1.
A driven pulley 3 integrally formed on the outer circumference of 4
6. Therefore,
The main shaft 14 is rotationally driven by a motor 33.

The ratio of the number of teeth between the sun gear 22 and the planetary gear 23 is N:n. N is the number of long grooves 2, and n is the number of blade portions 19 of the blade 18. In this embodiment, the tooth ratio is 8:6. Therefore, when the main shaft 14 rotates once, the phase of the cutter 18 becomes N/n with respect to one point on the circumference of the workpiece 1.
In this embodiment, the angle is advanced by 8/6.

Further, the ratio of the number of teeth between the driving gear 28 and the driven gear 26 is equal to the ratio of the number of teeth between the sun gear 22 and the planet gear 23.

Next, the action will be explained.

First, the workpiece 1 is fixedly held by a clamp device (not shown). As shown in FIG. 5, the table 11 is advanced in the direction of the work 1 by the fluid pressure cylinder 12 with the cutter 18 positioned on the axis 14C of the main shaft 14. At this time, the knife 18
Since the outer diameter of the cutter 18 is set to be smaller than the inner diameter of the work 1, the cutter 18 enters the hollow part of the work 1. The cutting edge of any blade portion 19 in the cutter 18 is located at the long groove 2 to be cut on the inner circumferential surface 1A of the workpiece 1.
When the cutter 18 is located at the cutting start point, the advance of the cutter 18 is stopped.

Subsequently, the motor 32 drives the worm 30, the worm wheel 29, the driving gear 28, and the driven gear 2.
6. Via the feed female screw shaft 25 and the male screw portion 24,
The blade shaft 16 is advanced in the direction of the shaft center 15C. As the blade shaft 16 moves forward, the blade 18 comes into contact with the inner circumferential surface 1A of the workpiece 1, which becomes the starting point of the long groove 2, and cutting starts from there.

Here, when the main shaft 14 is rotated by the motor 33, the sub-shaft 15 revolves around the axis 14C.
At the same time, since the planetary gear 23 of the subshaft 15 meshes with the sun gear 22, the subshaft 15 rotates in accordance with the gear ratio thereof. The rotation of this sub-shaft 15 is caused by the spline 17
is transmitted to the blade shaft 16 via the blade shaft 16, the blade shaft 16 rotates, and the blade 18 performs cutting.

The cutter 18 is rotated and moved forward by the motor 32 from the position indicated by the imaginary line shown in FIG. 6A to the position indicated by the solid line. This amount of advance defines the depth of the long groove 2. When the depth of the long groove 2 reaches a predetermined value, the motor 32 is stopped, and the forward movement of the cutter 18 in the direction of the axis 15C is stopped.

Due to the rotation and revolution of the cutter shaft 16, the cutter 18 fixed to the cutter shaft 16 performs a so-called misosuri movement. That is, the blade shaft 16 is aligned with the axis 14 of the main shaft 14.
The cutter 1 is inclined at an angle of inclination α with respect to C.
8, its rotation center O18 is shifted from the revolution center O14 due to the amount of tilt advance, that is, the amount of advance in the direction of the axis 15C (assuming the amount of tilt advance is L, L×
There is a deviation by Sinα, and this deviation amount corresponds to the depth of the long groove 2. ) Therefore, due to the revolution, it performs a swinging motion with the revolution center O14 as the base point. At the same time as this swinging motion, the blade 18 is fixed perpendicularly to the blade axis 16, so the radius of the cutting edge of the cutting edge 19 is changed to γ.
Then, at the cutting edge of the cutting edge 19, γ×Sinα
The blade moves with a swing width of , due to the rotation of the blade shaft 16. Such a swinging motion and a swinging motion are combined to produce a so-called misosuri motion. In this scraping motion, the amplitude becomes the groove cutting stroke for the long grooves 2 of the group of blades 19 per rotation of the main shaft 14.

Therefore, if the table 11 is moved in the direction of the workpiece 1 by the cylinder 12 while rotating the main shaft 14, and the cutter 18 is moved parallel to the workpiece 1, the long groove 2 can be continuously cut by the cutting stroke. Processing will be carried out.

When two groups of long grooves of a predetermined length are formed on the inner circumferential surface of the workpiece 1, the motor 32 serving as a sliding drive means is reversely rotated to move the cutter shaft 16 back toward the axis 15C, thereby causing the cutter 18 to rotate. Center revolves around center O18
O14, that is, position it on the axis 1C. After reaching this state, the table 1 is
1 is retreated in a direction away from the workpiece 1, the cutter 18 can be extracted from the hollow portion of the workpiece 1.

By the way, the number N of long grooves 2 and the cutting edge 1 of the cutter 18
Although it is different from the number n in 9, since the ratio of the number of teeth between the sun gear 22 and the planetary gear 23 is set to N:n, the phase of the cutting edge 19 is changed by one rotation of the main shaft 14, that is, one revolution. Upon hitting, the angle is advanced by N/n, and this advance compensates for the difference between both N and n, and two groups of long grooves of a predetermined number are naturally arranged equiangularly radially on the inner circumferential surface 1A of the workpiece 1. It is being cut while being calculated.
At this time, adjacent cutting edges 19, 1 in the cutter 18
Since the circumferential pitch between the grooves 9 and 9 is equal to the circumferential pitch between the adjacent long grooves 2 on the inner circumferential surface 1A of the workpiece, indexing is performed to arrange the two groups of long grooves in an equiangular radial pattern.

The cross-sectional shape of the long groove cut in this way is defined by the locus of movement of the cutting edge of the cutting blade 19, and therefore becomes close to a trochoidal curve.

According to this embodiment, 8
While the two groups of book long grooves are indexed and arranged equiangularly and radially, the respective long grooves 2 can be formed simultaneously. Therefore, a complicated indexing mechanism can be omitted, and cutting efficiency can be greatly improved. Further, since the long groove group with both ends closed can be formed at once, there is no increase in the number of parts.

In the above embodiment, a case was explained in which a group of long grooves with both ends closed is cut, but it goes without saying that a group of long grooves with both ends open can be cut more easily. It is particularly effective when

In the embodiments described above, an external gear is used as the sun gear, but it may also be an internal gear. Further, the driving means for reciprocating the blade shaft is not limited to the structure including the feed screw mechanism, but may also use, for example, an electromagnetic plunger mechanism, a fluid pressure mechanism, or the like. moreover,
It goes without saying that the means for rotationally driving the main shaft, the means for slidingly driving the table, etc. are arbitrary.
Further, since the table only needs to be moved relative to the work, the work side may be movable.

As described above, according to the present invention, a plurality of long grooves whose both ends are closed can be indexed and arranged at equiangular radial positions on the inner circumferential surface of a workpiece, and simultaneously cut.

[Brief explanation of drawings]

Figures 1A and B are side sectional views and front views showing processed products, Figures 2 A and B are side sectional views and front sectional views showing an example of a conventional processing method, and Figure 3 is a side sectional view and front sectional view showing an example of a conventional processing method. FIG. 4 is a side sectional view showing another example of the conventional processing method, FIGS. 5 and 6 show an embodiment of the present invention, and FIG. FIG. 5 is a side sectional view showing the overall configuration, and FIGS. 6A and 6B are an enlarged partial side sectional view and an enlarged partial front sectional view for explaining the operation. 1... Workpiece, 1A... Inner peripheral surface, 2... Long groove,
11...Table, 12...Fluid pressure cylinder, 1
3...Bearing block, 14...Main shaft, 15...Subshaft, 16...Cutter shaft, 17...Spline, 18
...Star-shaped knife, 19...Cutting blade, 20...Stand, 21...Spindle, 22...Sun gear, 23...
Planetary gear, 24... Male threaded portion, 25... Feed female threaded shaft, 26... Driven gear, 27... Drive shaft, 28
...Driving gear, 29...Worm wheel, 30
...Worm, 31...Box, 32...Motor, 33...Spindle drive motor, 34, 36...
Pulley, 35...belt.

Claims (1)

[Claims] 1. In a long groove cutting device for cutting a plurality of long grooves on the inner circumferential surface of a cylinder, each of which is closed at both ends, parallel to the cylindrical center and to the same depth, the cylinder is provided with a table that moves relatively in parallel with the cylindrical center. , a bearing block held on the table, a main shaft rotatably supported by the bearing block, and a cylindrical shape rotatably supported by the main shaft with its cylindrical center inclined with respect to the axis of the main shaft. a sub-shaft, a cutter shaft supported by the sub-shaft so as to be slidable in the direction of the cylindrical core in a non-rotating state, and a cutter shaft fixed to one end of the cutter shaft that may intersect with the axial center extension line of the main shaft. , a star-shaped cutter having an appropriate number of cutting edges protruding in the radial direction of the cutter shaft, a sun gear fixed to the table, and a planetary gear meshing with the sun gear and fixed to the subshaft. A long groove cutting device for a cylindrical inner surface, comprising: a driving means for reciprocating and slidingly driving the blade shaft.