JPH0220656Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is used to hold and fix the inner diameter of the rotating body in a balance measuring device when measuring the dynamic balance of a small and lightweight rotating body, especially an impeller for a turbocharger. This invention relates to an axial elastic chuck for measuring dynamic balance.

(Prior Art) An impeller mounting jig (chuck) 1 used to measure and correct the dynamic balance of an impeller for a turbocharger is a cylindrical jig that fits into the inner diameter part 2a of an impeller 2, as shown in Fig. 1. A component attachment part 3 is provided at one end, and a tapered part 4 that becomes thinner toward the tip to be attached to a balance measuring device is provided at the other end.
A threaded part 5 for mounting a nut used when removing the chuck from the balance measuring device is formed at the end of the tapered part 4 on the component mounting side, and an axial through hole 6 is formed in the center of the chuck 1, and the component mounting part 3 is formed at the end of the tapered part 4 on the component mounting side. A small hole 7 for air venting perpendicular to the through hole 6 is bored between the screw portion 5 and the screw portion 5. The component attaching portion 3 is provided with a component tightening screw hole 8 having a fine thread formed from the end face toward the threaded portion 5 side, so that a bolt 9 can be attached thereto.

When installing the impeller 2, in order to avoid play due to the internal diameter tolerance of the parts, prepare multiple shaft diameters of the component mounting part 3 according to the degree of tolerance, and minimize play due to fitting with the parts. After selecting and fitting one with a shaft diameter with good compatibility, the bolt 9 is screwed into the screw hole 8 for tightening the component, and the impeller 2 is tightened and fixed. The axial length of the component mounting portion 3 is made shorter than the longitudinal dimension of the impeller (the axial length of the impeller inner diameter portion 2a), so that when the bolt 9 is tightened, the end surface of the component mounting portion 3 and the thread side end surface of the bolt 9 are connected. between impeller 2
A gap 10 is provided to allow sufficient tightening.

In such an impeller mounting jig 1, the impeller longitudinal dimension tolerance is plus or minus 0.2 mm (±0.2 mm), so the stopping position of the bolt 9 differs for each measured part and is affected by the amount of imbalance in the bolt. Therefore, accurate balance measurements cannot be made. This causes vibration defects in the turbocharger assembly.

(Purpose of the invention) The present invention is intended to improve the above-mentioned drawbacks, and even when the longitudinal dimensions of the attached parts differ, the stopping position of the threaded part is kept constant, and highly accurate balance correction is possible. The present invention provides an axial elastic chuck for dynamic balance measurement that reduces the vibration defect rate.

(Structure of the invention) The feature of the invention is that a component mounting shaft is integrally provided on the main body of the axially elastic chuck for measuring dynamic balance so that its axis coincides with the main body.

Then, a hollow mounting component end face presser having one end integrally fixed to the main body and having a gap between the other end and the outer periphery of the component mounting shaft and having flexibility in the axial direction of the component mounting shaft is provided. establish. Another feature is that a female screw portion for tightening the attached component is provided at the center of the free end of the component mounting shaft.

(Function) Since the present invention is constructed in this way, the main body of the axially elastic chuck, the end face presser of the mounting component, and the component mounting shaft are integrated, and the axially elastic chuck itself for dynamic balance measurement, which is composed of these components, The dynamic balance is established as unique, and the correction of the dynamic balance of the object to be measured is accurately determined.

In addition, one end of the end face presser is integrally fixed to the main body and a gap is provided between the other end and the component mounting shaft, so the object to be measured is mounted on the component mounting shaft and the bolt is attached to the threaded part at the tip of the component mounting shaft. When 9 is tightened, the flexible end face holder is bent and the object to be measured is fixed to the main body even if there is a machining error in the length.

This makes it possible to adjust the tightening position of the bolt, and eliminates the influence of the bolt tightening position on dynamic balance.

(Example) Hereinafter, embodiments of the present invention will be described with reference to the drawings.

An axially elastic chuck 11 for attaching an impeller 2 of a centrifugal compressor for a turbocharger to a balance measuring device consists of three parts: a main body 12, a component attachment shaft 13, and a bolt 14, as shown in FIG.
The component mounting shaft 13 has a threaded part 13a screwed into the main body at one end, a threaded part 13b screwed into the bolt 14 at the other end, and the central part serves as a fitting part with the impeller 2. . The main body 12 has an insertion part 15 for the balance measuring device having a tapered surface at one end, and a threaded part 16 for screwing a nut for removing the balance measuring device at the maximum diameter position of the insertion part. A flange portion 17 is provided at an end of the threaded portion 16 located on the opposite side of the insertion portion 15. A threaded portion 18 (see FIG. 3) is provided at the center of the end face of the flange portion 17 for screwing the threaded portion 13a of the component mounting shaft 13 into engagement. Flange part 17
At the end of the component mounting shaft 13, a bellows type spring 19 having a hole with an inner diameter larger than that of the component mounting shaft 13 or a bellows type spring 19 like a stack of disc springs, and an end face holder 20 that comes into contact with the end face on the back side of the boss part of the impeller 2 are attached in the axial direction. Attach by overlapping and welding. The end face presser 20 has a hole (not shown) with a diameter larger than the fitting part of the component mounting shaft 13 with the impeller 2 so that it can loosely pass through the fitting part of the component mounting shaft 13 with the impeller 2. The contact surface 20a has a perpendicularity and flatness after being attached to the main body so that it can evenly contact the end surface on the back side of the boss portion of the impeller 2.

With such a configuration, the component mounting shaft 13 is fixed by welding after the threaded portion 13a of the component mounting shaft 13 is attached to the threaded portion 18 of the flange portion 17.
The bolt 14 is attached to the threaded portion 13b of the component mounting shaft 13,
The threaded portion 14a can be screwed up to the root thereof, and the end face of the bolt 14 comes into contact with the end face of the component mounting shaft 13, so that the tightening completion position is fixed. Impeller 2 and component mounting shaft 1
3, even if the boss portion of the impeller 2 has a different axial length due to the dimensional tolerance, the end face presser 20 that presses the end face moves in the axial direction due to the action of the spring 19. Absorbs variations due to dimensional tolerances.

As another aspect of this type, as shown in FIGS. 3 and 4, a step is provided on the component mounting shaft 13, and the thicker end is set as the impeller fitting shaft portion 13c, and the axial length is the same as that of the boss portion of the impeller 2. Make it shorter than the axial length,
One plane 21 with the narrower end as the end face fitting part 13d.
will be established. The spring 19 and the end face holder 20 are not fixed to the flange portion 17, and the hole 22 of the end face holder 20 has the same cross-sectional shape as the end face holder fitting portion 13d.

In this way, the threaded part 13a of the component mounting shaft 13 is attached and welded to the threaded part 18 of the main body 12, and the impeller 2 is attached to the impeller fitting shaft part 13 of the component mounting shaft 13.
c and screw the bolt 14 into the threaded portion 13b until its end surface abuts the end surface of the component mounting shaft 13. Then, the action of the spring 19 causes the end surface presser 20 to come into contact with the back end of the boss portion of the impeller 2. The impeller 2 is clamped by applying a pressing force to the impeller side. At this time, with respect to the amount of change in the axial length of the boss portion of the impeller 2, the end face presser 20 moves in the axial direction to absorb the change in dimension.

In the second embodiment of the present invention, as shown in FIGS. 5 and 6, a cylindrical portion 31 is provided integrally with the main body 12 at the end opposite to the tapered portion of the main body 12. 31 is provided with a plurality of slits 32 at equal intervals on the circumference, and an end face presser 33 is formed by bending the tip of an axially elongated strip inward to form a leaf spring.
The tip of the end face presser 33 has rounded corners 33a and 33b, as shown in FIGS. 6A and 6B, to prevent damage to the impeller 2. With such a configuration,
When the end face presser 33 comes into contact with the end face on the back side of the boss portion of the impeller 2, it bends inward and elastically deforms as the bolt 14 is tightened, and the impeller 2 is clamped and fixed together with the bolt 14 by its spring action. .
This produces the same effect as in the case of FIGS. 2 and 3.

As another aspect of this type, as shown in FIG. 7, the slit 34 provided in the cylindrical portion 31 is provided at an angle with respect to the axis, and the strip-shaped end face presser 35 is formed substantially long. This makes it easier to bend compared to the case shown in FIG. 5, and the length of the cylindrical portion 31 in the axial direction can be shortened in order to obtain relatively the same effect.

In this embodiment configured in this way, the end face pressers 20, 33, and 35 are integrally fixed to the main body 12 via the spring 19 and the cylindrical part 31, respectively, and the component mounting shaft 13 is also fixed to the main body 12. 12 and are integrally fixed.

Axial elastic chuck 1 integrated in this way
The dynamic balance when 1 rotates at high speed is determined as something unique to the axially elastic chuck. Further, since the bolt 14 is a separate part from the axially elastic chuck 11, the bolt 14 is screwed to the screwing stop position to be integrally connected to the axially elastic chuck 11, and the dynamic balance for this is determined. If the axial elastic chuck 11 including the bolt 14 is
The unique dynamic balance can be determined.

Then, attach the impeller 2 to the component mounting shaft 13,
By screwing and fastening the bolt 14 to the threaded portion 13b, the end face holders 20, 33, 35 are integrated with one end fixed to the main body 12 and the other end with a gap provided between the component mounting shaft 13. The impeller 2 is fixed to the main body 12 by the deflection force. Therefore, even if the tightening position of the bolt 14 is slightly deviated, the impeller 2
is fixed by the bending force of the end holders 20, 33, and 35 (the flexing force of the spring 19 in the case of the end holder 20), so even if there is a machining error in the length direction of the impeller 2, the bolt 14 can be tightened. The mounting position can be adjusted, and it is possible to eliminate the influence of the tightening position of the bolt 14 on dynamic balance.

In addition, end face holders 20, 33, 35 are used to tighten the bolt 14 until it reaches its tightening limit.
If the dimensions of the component mounting shaft 13 are determined, the dynamic balance of the axial elastic chuck 11 including the bolt 14 is determined, so the dynamic balance of the impeller 2 can be corrected accurately, resulting in high precision. It becomes possible to measure the dynamic balance of the impeller 2.

(Effects of the invention) As detailed above, according to the invention, since the main body, end face holder, and component mounting shaft are integrated, the dynamic balance unique to the axial elastic chuck can be determined, and the movement of the object to be measured can be determined. The dynamic balance of the object to be measured can be measured with high precision by accurately correcting the balance.

One end of the flexible end presser is integrally fixed to the main body, and a gap is provided between the other end and the outer circumferential surface of the component mounting shaft, so that the bending force of the end presser allows the object to be measured to be attached to the main body. can be fixed to.

Therefore, even if there is a machining error in the longitudinal direction of the object to be measured, the object to be measured is fixed to the main body without being affected by the tightening force of the bolt, and the tightening position of the bolt can be adjusted to eliminate the influence of the dynamic balance of the bolt. Even if there is a processing error in the object to be measured, its dynamic balance can be measured with high precision.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view showing a conventional impeller mounting jig for dynamic balance measurement, Fig. 2 is a partial sectional view showing an axial elastic chuck for dynamic balance measurement using a bellows type spring of the present invention, and Fig. 3. Figure 4 is a partial cross-sectional view showing an axial elastic chuck for dynamic balance measurement using a bellows type spring in which a flat surface is provided on the component mounting shaft to form a rotation stopper, and Figure 4 is a cross-sectional view taken along the - line in Figure 3. 5 is a half-sectional view showing an axial elastic chuck for measuring dynamic balance using a rectangular leaf spring,
Figure 6 A is a partially enlarged plan view showing the rounding of the end presser, Figure 6 B is a partially enlarged side view showing the rounding of the end presser, and Figure 7 is dynamic balance measurement using a rectangular leaf spring with an inclined groove. FIG. 3 is a half-sectional view showing an axially elastic chuck for use. 11... Axial elastic chuck, 12... Main body, 13
...Component mounting shaft, 13a...Component mounting shaft side threaded part, 1
3e... Relief groove, 14... Bolt, 17... Flange part, 18... Body side threaded part, 19... Bellows type spring, 2
0, 33, 35...End face presser.

Claims (1)

[Scope of utility model registration request] A component mounting shaft is integrally provided on the main body of the axially elastic chuck for dynamic balance measurement so that its axis coincides with the main body, one end is integrally fixed to the main body, and the other end is interposed between the outer periphery of the component mounting shaft. A flexible hollow end face presser for the component mounting shaft is provided with a gap in the axial direction of the component mounting shaft, and a female screw portion for tightening the mounting component is provided at the shaft center of the free end of the component mounting shaft. An axial elastic chuck for measuring dynamic balance.