JPS6274517A - Manufacture of insert axis - Google Patents

Abstract

PURPOSE:To make easy the processing of non-circularity part for ensuring coupling with synthetic resin and ensure working efficiency by making a tool get in contact with the external surface of a workpiece while eccentrically turning the center of a rotary axis, and forming a crescent form recess through cutting a part of the entire periphery. CONSTITUTION:An independent chuck mechanism causes the deep movement of only a claw 11a and the shallow movement of other two claws 11b and 11c, as claws 11a, 11b and 11c supported on a body 10 are able to work independently of each other. As a result, the center C1 of a rotary axis 1 chucked with three claws 11a, 11b and 11c comes to be out of alignment with the center C2 of the chuck body 10. The turning of the chuck device causes the eccentric turn of the rotary axis 1 and makes it possible to form a recess 6 of a crescent. When the external surface of a workpiece is machined as aforementioned, it is possible to carry out a secondary process simply through the eccentric mounting of the axis 1 after a primary process by repeating similar work.

Description

[Detailed Description of the Invention] [Summary] In order to insert a metal shaft into a synthetic resin and join it together, a crescent-shaped recess is formed in a part of the side surface of the shaft, so that the cross-sectional shape becomes non-uniform. It is effective to form a perfectly circular portion and insert this portion into a synthetic resin. In the present invention, when forming this non-circular portion, a metal perfect circular shaft is
A rotary drive mechanism holds the metal shaft so that the rotation center is at a position offset from the center, rotates the metal shaft in an eccentric state, and applies a tool from the side to create a crescent-shaped recess in a part of the side surface of the rotating shaft. By forming a non-circular portion, it is possible to easily and efficiently process the non-circular portion.

[Industrial application field]

In order to insert a rotating shaft into synthetic resin, such as a motor rotor, and join it together, a part of the perfectly circular rotating shaft must be deformed to ensure a secure connection with the synthetic resin part. There is. The present invention relates to a method of manufacturing an insert shaft that is inserted into a synthetic resin and integrally bonded.

[Conventional technology]

FIG. 2 is a diagram showing a conventional mechanism for preventing the insert shaft from being pulled out, in which (A) is a longitudinal cross-sectional view cut in the axial direction, and (B) is a cross-sectional view of the roller of FIG. Reference numeral 1 denotes a rotating shaft, which is integrated with a rotor member 3 such as a magnet via a synthetic resin portion 2 . The rotating shaft 1 and the synthetic resin part 2 are connected to each other in order to prevent them from slipping out or idling.
As shown in the figure, a flat cut is partially made to form a recess 4, thereby forming a D-shaped cross section. By inserting the L-shaped cross section into the synthetic resin 2 in this manner, the coupling force in the axial and rotational directions of the rotating shaft 1 is maintained.

Further, as shown in FIG. 3, a keyway-shaped groove 5 is provided on the rotating shaft 1
It is also possible to form a groove and insert this groove into the synthetic resin 2. It is also possible to perform low left processing on the outer periphery of the rotating shaft l to form irregularities, and to insert this part into the synthetic resin.

The finishing of the rotating shaft 1 is carried out by cutting the outer periphery with a cutting tool while rotating the rotating shaft 1 with a lathe.
Cut part 4? Formation of n5 is performed using a milling machine or the like. Knurling is also performed using a different tool from lathe processing. In this way, special secondary processing is required in addition to the outer peripheral processing of the rotating shaft 1, but this secondary processing adds a shape change to the perfectly circular rotating shaft, and as a result, the strength of the rotating shaft 1 is reduced. Therefore, when used as a product, there was a problem in that breakage was likely to occur from the removal stop portion. Furthermore, machining of the pull-out stop portion requires secondary machining that is completely different from secondary machining, resulting in poor manufacturing efficiency and high costs.

Therefore, in order to solve these problems, a removal prevention mechanism as shown in FIG. 4 has been proposed. FIG. 4 is a sectional view corresponding to FIG. 2, showing an embodiment of the mechanism for preventing the insert shaft from being pulled out. A crescent-shaped recess 6 is formed in a part of the outer surface of the metal rotating shaft 1. Therefore, in the portion 1a in which the crescent-shaped recess 6 is formed, the outer peripheral shape of the rotating shaft 1 is a non-perfect circle consisting only of circular arcs. The portion having the crescent-shaped recess 6 and the inner portions on both sides thereof are inserted into the synthetic resin portion 2 as shown in (A).

With the rotating shaft 1 inserted into the synthetic resin part 2,
A rotational force and an axial force act relatively between the two. Due to the stepped portion 7 between the non-perfect circular portion 1a inserted into the synthetic resin portion 2 and the true interior on both sides thereof,
An axial connection takes place and a pull-out prevention action takes place. In addition, since the part where the crescent-shaped recess 6 is formed is a non-perfect circular part 1a, this part and the crescent-shaped recess 6
Connection in the rotational direction is performed by the synthetic resin part inside,
rotates as one.

The outer periphery of the non-circular portion 1a for preventing removal is also arcuate, and the cross-sectional shape does not change greatly between the true inner part and the shape in the circumferential direction. Does not occur. Therefore, by forming the crescent-shaped recess 6, the mechanical strength is not extremely inferior to that of the inner part, and at least the strength decrease is less than that of conventional D-cuts, key grooves, knurling parts, etc.

[Problem that the invention seeks to solve]

In order to form such a non-circular portion 1a, if the rotary shaft 1 is made of synthetic resin or the like, it can be formed by molding, but if it is made of metal, cutting or grinding is easier. An object of the present invention is to enable the non-circular portion to be formed easily and efficiently when forming the non-perfect circular portion on a portion of the metal shaft.

[Means for solving problems]

FIG. 1 is a sectional view illustrating the basic principle of the method for manufacturing an insert shaft according to the present invention. The rotating shaft 1 made of metal is usually processed into a perfect circular rod shape by secondary processing. In this case,
The rotary shaft 1 is held in a lathe or the like so that the center C1 is the center of rotation, and a perfectly circular shaft is formed by grinding the entire length with a tool such as a cutting tool while rotating the rotary shaft 1. After the outer circumferential machining of the rotating shaft 1 is completed, the rotation center is set at position 02, which is offset from the center CI of the rotating shaft 1.
Set it on the processing machine with the center of rotation eccentric. Then, while rotating the rotary shaft 1 eccentrically, a tool 8 such as a cutting tool is abutted against the outer periphery to cut only a portion of the entire periphery.

[Effect]

When cutting from the outer periphery while rotating the rotary shaft 1 about the eccentric point C2 as the center of rotation, only the portion 91 that is a large distance from the center of rotation C2 is cut. Further, only the outer circumferential portion 91 having a large distance from the rotation center C2 is cut deeply, and the portion 92 close to the rotation center C2 is cut shallowly.

Since the distance (radius) r of this cut portion from the rotation center C2 is naturally constant, the cut portion becomes a crescent-shaped concave portion as shown by 6.

〔Example〕

Next, how the method for manufacturing an insert shaft according to the present invention is actually implemented will be explained using examples. FIGS. 5 and 6 show an embodiment in which the rotating shaft 1 is held eccentrically. FIG. 5 shows an example in which a single chuck is used as a chuck for a lathe, and FIG. 6 shows an example in which a scroll chuck is used.

In the independent chuck mechanism shown in FIG. 5, since the winter melons 11a, llb, and IIG supported by the main body 10 can be operated independently, only one claw 11a is moved deeply, and the other two claws 1
1b and 11c are moved shallowly. As a result, three claws 1
The center C1 of the rotating shaft 1 chucked by 1a, jib, and IIC is chucked in a state shifted from the center C2 of the chuck body 10, and by rotating the chuck device, the rotating shaft 1 rotates eccentrically, forming a crescent-shaped It becomes possible to form a recessed portion 6 of.

When chucking with the scroll chuck mechanism shown in FIG. 6, the winter melons 11a, llb, and Hc move simultaneously and have the same amount of movement, so the block 12 is sandwiched between one claw 11a and the rotating shaft l. Then, the center C1 of the rotation axis l shifts from the center C2 of the main body 13 by the thickness of the block 12, resulting in a deviation;
It will be held in place. - Fig. 7 is an example of using a jig for eccentric mounting of the rotating shaft l. As shown in (b), a mounting hole 15 is drilled in the jig 14 at a position offset from the center C2 by an eccentric amount, and the rotating shaft l is inserted and fixed therein, as shown in (a). Attach the jig 14 to the chuck mechanism of the lathe. At this time, the jig 14 is attached so that the center C2 of the chuck body 13 of the lathe and the center C2 of the jig 14 coincide. Then, with the center C1 of the rotation axis 1,
The crescent-shaped recess 6 can be easily formed in a part of the outer periphery of the rotating shaft 1 to form the eccentric shaft portion 1a. In particular, when performing outer peripheral machining directly inside the rotary shaft 1, following the primary machining for the outer peripheral machining, simply attach the rotary shaft 1 eccentrically and repeat the same procedure as the secondary machining. Next processing can be performed, and the next processing and secondary processing have the same work content.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view explaining the basic principle of the method for manufacturing an insert shaft according to the present invention, Fig. 2 is a cross-sectional view showing an insert part using a conventional D cut, and Fig. %3 shows an insert part using a conventional keyway. 4 is a sectional view showing an insert state of an insert shaft manufactured by the method of the present invention,
5 and 6 are front views showing an embodiment of a method for eccentrically holding a rotating shaft when manufacturing an insert shaft by the method of the present invention, and FIG. They are a sectional view and a front view of the tool. In the figure, 1 is the rotating shaft, 2 is the synthetic resin part, 4 is the D-cut part, 5 is the keyway, 6 is the crescent-shaped recess, 1a is the non-round part, 8 is the tool, and 91 is from the center of rotation C2. far part, 9
2 is the center of rotation, a portion near C2, 10.13 is the chuck mechanism body, lla, llb, and llc are claws, and 12 is a block.

Claims (1)

[Claims] A method for manufacturing an insert shaft that is inserted into a synthetic resin and integrally bonded, the method comprising rotating a perfectly circular metal shaft such that the center of rotation is at a position offset from the center of the shaft. The metal shaft is held in a mechanism and rotated in an eccentric state, and a tool is applied from the side to form a crescent-shaped recess in a part of the side surface of the rotating shaft. A method of manufacturing an insert shaft, characterized by forming an insert shaft.