JPS6236819B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an eccentric shaft machining jig.

There is no special jig for machining eccentric shafts. For this reason, conventionally, first, the first axis O is centered on both end faces of the shaft. Next, it is supported by the axis O at both ends, and the outer periphery is machined using a lathe. After finishing the outer circumferential machining, the second axis P, which is eccentric from the axis O by a predetermined distance, is again centered on both end faces. Next, while supporting the shaft center P, the outer periphery of both end shafts is machined using a lathe. As a result, the shaft body and both end shafts form an eccentric shaft in which the respective shaft centers O and P are eccentric.
Since processing has to be done in this way, centering must be performed twice on both end faces, which is complicated, and furthermore, it is extremely difficult to perform centering work in which the eccentric direction and amount of eccentricity of both end shafts are exactly the same. It's a lot of work.

The present invention eliminates the need for this particularly difficult centering work of both end shafts, simplifies processing, and improves workability.
Furthermore, it is an object of the present invention to provide an eccentric shaft machining jig with high precision in the eccentric direction and eccentricity amount of the machined both end shafts.

Examples of the present invention will be described. In the first, second, and fourth illustrations, the processing jig is formed by fitting an outer cylinder 1 and an inner cylinder 2, and the outer cylinder 1 has an axial center line.
O ₁ is cylindrical, and the eccentric shaft hole _1a is centered on the axial center line O ₂ at a position of eccentricity δ ₁ from the axial center line O 1.
has been drilled. Fixing screw holes 1b, 1b are bored through the eccentric shaft hole 1a. Fixing screws 3, 3 are screwed into the fixing screw holes, and a hexagonal recess 3a, for example, is bored in the outer end surface of the fixing screw. It is desirable that at least two fixing screw holes 1b are provided in the axial direction.

As shown in Figures 1, 2, and 5, the inner cylinder 2 has a cylindrical shape with a length that fits into the eccentric shaft hole 1a of the outer cylinder 1 and has both ends protruding. The line coincides with the axial center line _O2 of the eccentric shaft hole 1a. An eccentric shaft _2a is bored around the axis _O3 at a position of eccentricity _δ2 from the axis O2. In this example, δ ₁ =δ ₂ =δ is set. Screws 2b are formed at both ends of the inner cylindrical body 2, and chucks 4, 4 are inserted into both ends of the eccentric shaft hole 2a,
By screwing the mounting screws 5, 5 into the screw 2b, the chuck is connected to the chuck so that it can move forward and backward, but cannot escape.

The inner cylindrical body 2 is rotatable relative to the outer cylindrical body 1,
The means is such that a worm gear 6 is formed in a band shape on the outer peripheral surface of the inner cylinder 2, and a worm 7 is meshed with the worm gear 6. Worm 7 is outer cylinder body 1
It has a rotatable bearing. In the example shown in the second diagram,
E-rings 8, 8 are fitted into the grooves at both ends of the worm 7 to prevent them from escaping, and the shaft portion protruding from the E-ring is formed into a hexagonal shape and is rotated by a hexagon spanner or the like.

In order to easily see the rotational positions of the inner cylinder 2 and the outer cylinder 1, a reference line 9 (Fig. 1) is drawn on the outer peripheral surface of one end of the inner cylinder 2, and a radial line is drawn on one end of the outer cylinder 1. A scale line 10 is drawn.

11 is a shaft to be machined, and 11a is a small shaft whose one end is turned.

Since the processing jig of the present invention has such a configuration, the worm 7 is rotated to feed the worm gear 6, thereby rotating the inner cylinder body 2. Outer cylinder body 1
Due to the relative rotation between the inner cylindrical body 2 and the inner cylindrical body 2, the axis _O3 of the eccentric shaft hole 2a moves along a circular trajectory 12, as shown in FIG.
move along. For this purpose, the eccentric shaft hole of the inner cylindrical body 9 continuously changes its position from the position 2a, through the position 2a' indicated by the dotted line, and further to the position 2a' indicated by the chain line. As shown in the first figure, a shaft 11 to be machined is held in the eccentric shaft hole 2a through a chuck 4 with both ends thereof protruding from the chuck. This is held by the chuck 13 of the lathe, and the shaft to be machined 11
By turning the protruding end of the shaft, a small shaft 11a is formed on one end surface. The axial center line of the shaft to be processed 11 coincides with the axial center line O ₃ of the eccentric shaft hole 2a, and the axial center line of the small shaft 11a coincides with the axial center line O ₁ of the outer cylinder 1, so
The maximum eccentricity of the small shaft 11a is δ ₁ +δ ₂ =2δ, and the minimum is δ ₁ −δ ₂ =0. That is, the amount of eccentricity of the small axis can be set to any amount within the range of 0 to 2[delta]. A reference line 9 and a scale 10 are used to set the amount of eccentricity prior to turning. In the example shown in the first figure, the reference line 9 is aligned with "0" on the scale 10, and the eccentricity of the small shaft 11a is zero. To maximize the amount of eccentricity, set the reference line 9 to “9” (third point) on the scale 10.
(as shown in the figure). Next, remove the processing jig from the chuck 13, turn it over and grasp the other end,
If the other end surface of the protruding shaft to be machined is turned, the other small shaft will be formed at exactly the same position as the small shaft.

Note that the eccentricity amount of 0 means that the small shaft 11a is formed concentrically, so when forming a small shaft that is always eccentric, it is not necessary to set δ ₁ = δ ₂ , but set it to an arbitrary value. do it.

As described above, according to the present invention, it is extremely easy to form a small shaft at the end of the shaft to be machined, any desired amount of eccentricity can be easily obtained, and the eccentric direction of the small shafts at both ends can be changed easily.
Since the accuracy of the amount of eccentricity is extremely high, it is advantageous for improving the quality of the machined eccentric shaft.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a sectional view of a processing jig, Fig. 2 is a sectional view taken along the line of Fig. 1, Fig. 3 is a right side view, and Fig. 4 is an outer cylinder. FIG. 5 is a side view of the inner cylindrical body, and FIG. 6 is an enlarged explanatory view for explaining the eccentric state. 1... Outer cylinder body, 1a... Eccentric shaft hole, 1b... Fixing screw hole, 2... Inner cylinder body, 2a... Eccentric shaft hole, 3
...Fixing screw, 4...Chuck, 5...Mounting screw, 6...Worm gear, 7...Worm.

Claims (1)

[Scope of Claims] 1. It has a cylindrical shape with an eccentric shaft hole, and a fixing screw hole passes through the eccentric shaft hole, and the fixing screw is screwed into the fixing screw hole. an outer cylindrical body gripped by a chuck of a lathe; an inner cylindrical body having an eccentric shaft hole formed therein, the inner cylinder fitting into the eccentric shaft hole of the outer cylinder holder, and having both ends protruding; chuck means provided at both ends of the inner cylindrical body and capable of gripping the shaft to be processed with both ends protruding; and means for rotating the inner cylindrical body relative to the outer cylindrical body. An eccentric shaft machining jig characterized by: