CN101664831A - Gear Hole Self-Centering Ball Clamp - Google Patents

Abstract

The invention provides a gear hole self-centering ball clamp which comprises a clamp mandrel, a gland, a disc spring, a centering taper sleeve, a ball ring, balls and a chassis. The fixture mandrel is sleeved with a ball ring and a centering taper sleeve, balls are placed in ball limiting holes in the ball ring, and the centering taper sleeve abuts against the balls. A gear blank is sleeved outside the ball ring, and the balls are propped against gear holes of the gear blank; the upper end of the centering taper sleeve is pressed with a disk spring. The invention has the advantages that: the fixture has large reducing amount, can be accurately centered, can be used for machining the teeth of a plurality of gears simultaneously, and a fixture mandrel does not need to be changed frequently. The clamp has the advantages of simple structure, time and labor saving and low manufacturing cost.

Description

Gear Hole Self-Centering Ball Clamp

technical field

The invention relates to a jig for gear external gear processing, which can be used for gear hobbing, gear shaping, shaving, honing, bevel gear cutting, and gear blank turning to maintain the concentricity of the outer circle and the inner hole; if the measuring tool is used for precise manufacturing, Also suitable for grinding teeth.

Background technique

In the gear machining process, to manufacture high-precision gears, it is necessary to control various error items in the machining process. When machining gears, the center hole and end face are mainly used as positioning references, so ensuring accurate centering is a very important method to improve machining accuracy.

In the current prior art, there are various gear hole centering fixtures, the widely used ones are the mandrel with centering bushing, or the self-centering fixture with micro-tapered mandrel with elastic sleeve, such as the German patent DE4,032,881 of ZIMMERMANN ( A1) (1992), the fixture described in the international patent WO83/03,562 (1983) of HUNKELER in the United States, the centering accuracy is 0.005 mm (grinding gear), 0.020 mm (precision hobbing) and 0.050 mm (retaining grinding gear blank) ) range. Others adopt the centering surface of the gear to be the center of rotation, such as the U.S. Patent US6,461,089B2 (2002) of the ROLF et al. of the Liebherr-Verzahntechnik GmbH company in Germany, and the patent 5,797,605 (1998) of the WILLIAMD et al. of The Gleason Works Company of the United States. , NEIL et al.’s U.S. Patent 5,251,510 (1993) recorded that its centering accuracy is still in the range of 0.005-0.020 mm, but it is troublesome to load and unload the workpiece and replace the centering element, the manufacturing cost of the fixture is high, and the centering of the tapered hole requires special equipment. .

There are common defects in the clamps of the above prior art:

1. The variable diameter is generally only in the range of half a millimeter;

2. The centering of the tapered hole requires special components;

3. Generally, it is not easy to hob multiple pieces;

4. The fixture manufacturing cost is high;

5. During single-piece and small-batch production, it is often time-consuming and laborious to replace fixtures.

Contents of the invention

The purpose of the present invention is to provide a gear fixture capable of processing single or multiple gear blanks, the fixture is suitable for a wide range of aperture changes, and can quickly and accurately center and clamp the gear strongly. The fixture makes the gear naturally centered, The centering element can be controlled with extremely high precision and has a large diameter change.

In order to achieve the above object, the present invention adopts the following technical solutions: it includes a fixture mandrel, a gland, a disc spring, a centering taper sleeve, a ball ring, and a chassis; a ball ring and a centering cone are set on the fixture mandrel There is a ball limit hole on the ball ring, and balls are placed in the ball limit hole. The centering taper sleeve is located in the ball ring and is on the ball. The ball is fixed by the ball ring and the centering taper sleeve at the upper end; The outer sleeve of the ball ring is equipped with a gear blank, and the ball is pressed against the inner hole of the gear blank; the bottom end of the ball ring is a chassis; the upper end of the centering taper sleeve is pressed with a disc spring; the upper end of the disc spring is pressed with a gland, The upper end of the gland is provided with a tightening nut screwed on the mandrel of the fixture.

There is a washer between the ball ring and the chassis.

The upper end cover of the ball ring has a retaining ring.

There is a top pressing block between the disc spring and the gland.

The top end of the clamp mandrel is a hexagon head integrated with the clamp mandrel, and a stop bar is fixed on the hexagon head.

A vertical upward bolt is installed on the gland.

The advantages of the present invention are:

1. The fixture has a large diameter change, and it is easy to replace centering elements such as balls and taper sleeves with a large diameter change. It is convenient to adapt to a wide range of changes in aperture, and can quickly and accurately center and clamp strongly. The parallelism of the end faces is high, and the teeth of multiple gears can be processed at the same time; several sets of fixtures are used, which is suitable for the self-centering of the most commonly used 150mm internal gear aperture, thereby saving thousands of centering bushes, or Dozens of elastic sleeve centering fixtures.

2. This jig can ensure the centering accuracy of precision hobbing; if it is manufactured accurately with measuring tools, it can become a grinding jig.

3. As long as the parallelism of the end face is high (rough grinding if necessary), multiple gear blanks can be overlapped and hobbed, which can double the hobbing time of the helical gear.

4. The mandrel of the fixture does not need to be replaced frequently, and it is convenient to replace the balls, saving time and effort.

5. The structure of the fixture is simple, mostly made of standard parts, and the cost is low.

6. Due to the high centering accuracy of this jig, the gear grinding allowance is more abundant, thereby reducing the accidental risk of grinding gear quality.

Description of drawings

Figure 1 is a schematic diagram of the structure of the unclamped state when the self-centering ball fixture processes a single-piece gear.

Fig. 2 is a structural schematic diagram of the clamping state when the self-centering ball fixture processes a single gear.

Fig. 3 is a sectional view of the ball race.

Fig. 4 is a plan view of the ball ring.

Fig. 5 is a view along the direction A in Fig. 3 .

Fig. 6 is a view taken along direction B in Fig. 3 .

Figure 7 is a top view of the retaining ring.

Fig. 8 is a sectional view of a gasket.

Figure 9 is a bottom view of the gasket.

Figure 10 is a composite view of the structure of two gears processed by the self-centering ball fixture (the left side of the center line is the unclamped state, and the right side is the clamped state).

Drawings

1. Fixture mandrel 6. Gear blank 10. Retaining ring

1a. Hexagon head 7. Ball ring 11. Washer

2. Gland 7a. Ball limit hole 12. Chassis

3. Disc spring 7b. Ring groove 13. Stop lever

4. Centering taper sleeve 8. Press block 14. Bolt

5. Ball 9. Tighten the nut 15. Top pressing block

Detailed ways

Referring to the accompanying drawings, what Fig. 1 represented is the unclamped state before the single-piece gear blank is processed. The present invention includes a fixture mandrel 1 , a gland 2 , a disc spring 3 , a centering taper sleeve 4 , a ball 5 and a chassis 12 . A ball ring 7 and a centering taper sleeve 4 are set on the fixture mandrel 1, and a ball limiting hole 7a is provided on the ball ring 7, and the ball limiting hole 7a is a tapered hole with a small outside and a big inside. Three or more precision balls 5 are placed in the ball limiting hole 7a, the diameter of the balls 5 is smaller than the diameter of the outer circle of the ball limiting hole 7a, and greater than the diameter of the inner circle of the ball limiting hole 7a, so the balls 5 are limited to In the ball ring 7, the ball 5 can roll toward the middle when the clamp is loosened, without falling outward. The centering taper sleeve 4 is located in the ball ring 7 and rests on the ball 5. The ball 5 is fixed by the centering taper sleeve 4 and the ball ring 7 at the upper end. The preferred taper angle of the centering taper sleeve is 70 degrees; The lowermost end is a chassis 12, and the chassis 12 is a high-hardness precision chassis. A gear blank 6 is set outside the ball ring 7, and the inner hole of the gear blank 6 is pushed together with the positioned ball 5; a disc spring 3 is pressed on the upper end of the centering taper sleeve 4; a disc spring 3 is pressed on the upper end Gland 2, there is a top pressure block 15 used as a gasket between the disc spring 3 and the gland 2, the upper end of the gland 2 is provided with a tightening nut 9, and the tightening nut 9 is screwed on the clamp mandrel 1 in the upper threaded section; the top end of the fixture mandrel 1 is a hexagonal head 1a integrated with the fixture mandrel 1, and a stop rod 13 is fixed on the hexagonal head 1a. , a vertically upward bolt 14 is installed on the gland 2 . Before the tightening nut 9 is tightened, there is a gap between the gland 2 and the top surface of the gear blank 6, and the disc spring 3 is in a relatively relaxed state.

Fig. 2 shows a schematic diagram of the structure when processing a single gear blank in a clamped state. Before processing the gear blank 6, due to the hydraulic pressure or when the nut 9 is tightened with a wrench, the gland 2 will press the disc spring 3 through the top pressing block 15, and the pressure block 8 will make it concentric with the rotary spindle of the machine tool. The centering taper sleeve 4 is pressed against the precision ball 5, and the ball 5 evenly pushes the gear hole, so that the gear blank 6 is naturally and accurately centered; Under the action of the resultant force of the centering taper sleeve 4 and the ball ring 7, it moves outwards to tighten the gear hole of the gear blank 6, so that the gear blank 6 is fixed on the clamp mandrel 1, and the gear blank 6 is strongly clamped. When the tightening nut 9 is tightened by a wrench, the gland 2 will rotate thereupon, and the bolt 14 will rotate along with the gland 2 to the retaining rod 13 fixed on the upper end of the fixture mandrel 1, thereby preventing the gland 2 from rotating, thereby Can continue to tighten screw nut 9, gear blank 6 obtains accurate centering, and is clamped strongly.

3 to 6 are schematic structural views of the ball ring 7 . Referring to FIG. 3 to FIG. 6 , the ball ring 7 has a ball limiting hole 7 a and a retaining ring groove 7 b. In the embodiment shown in FIG. 3 and FIG. 4 , the number of ball limiting holes 7 a is three, but the number is not limited according to the size of the processed gear blank 6 . There are three retaining ring grooves 7b on the ball ring 7, and the retaining ring grooves 7b are L-shaped grooves, which match the retaining ring 10 shown in Fig. 7 . Referring to Fig. 7, there is a three-lobed retaining ring fin on the retaining ring 10, which can be inserted into the retaining ring groove 7b. When the retaining ring 10 rotates in one direction, the retaining ring fins are clamped in the retaining ring groove 7b, the retaining ring 10 is tightly covered on the ball ring 7, and the balls 5 in the ball ring 7 and the centering taper sleeve 4 are locked together . After the processing is completed, the retaining ring 10 rotates in the opposite direction and can be taken off from the ball ring 7 . With this structure, the centering taper sleeve 4 can be easily replaced with balls 5 of different sizes and corresponding ball rings 7, so as to meet the needs of various apertures of gears conveniently.

Figure 8 and Figure 9 are schematic structural views of the washer 11. The washer 11 is a high-hardness washer, which is sandwiched between the ball ring 7 and the chassis 12. There is a notch at the bottom of the washer 11. The washer 11 is stuck on the chassis 12 by cutting oil. The screwdriver is easy to take out from the chassis 12 after the washer 11 is pried up from the notch.

The present invention can process a single gear blank 6, and can also process multiple gear blanks 6 at the same time as required, and the number of simultaneously processed gear blanks 6 can be 2-8. FIG. 10 is a schematic diagram of processing two gear blanks 6 . When more than two pieces are processed, the structure is similar to that shown in FIG. 10 , and the gear blank 6 is sleeved on the fixture mandrel 1 and superimposed together. Each piece of gear blank 6 is in one-to-one correspondence with a ball ring 7 and a centering taper sleeve 4 . When processing multiple gear blanks 6, a washer 11 is also sandwiched between the upper ball ring 7 and the lower pressing block 8. For more than two overlapping self-centering hobbed gear blanks 6 , especially for the helical gear blank 6 , the man-hours for gear cutting can be doubled, the processing efficiency is improved, and manpower and material resources are saved.

Claims (9)

1. A gear hole self-centering ball fixture, characterized in that it consists of a fixture mandrel, a gland, a disc spring, a centering taper sleeve, a ball ring, and a chassis. 2. The gear hole self-centering ball fixture according to claim 1, characterized in that: the ball ring and the centering taper sleeve are set on the fixture mandrel, the ball ring is provided with a ball limit hole, and the ball limit hole Balls are placed in the middle, and the centering taper sleeve is located in the ball ring, and it is supported on the ball. The ball is fixed by the centering taper sleeve and the ball ring at the upper end, and the ball ring is placed on the chassis; On the gear hole of the gear blank; a disc spring is pressed on the upper end of the centering taper sleeve; a gland is pressed on the upper end of the disc spring, and a tightening nut is arranged on the upper end of the gland, and the tightening nut is screwed on the fixture mandrel superior. 3. The gear hole self-centering ball clamp according to claim 1, 2, characterized in that: the taper angle of the centering taper sleeve is 70 degrees. 4. The gear hole self-centering ball clamp according to claims 1 and 2, characterized in that: the ball limiting hole on the ball ring is in the shape of an inverted cone. 5. The gear hole self-centering ball clamp according to claims 1 and 2, characterized in that: the upper end cover of the ball ring has a retaining ring. 6. The gear hole self-centering ball clamp according to claims 1 and 2, characterized in that there is a top pressure block between the disc spring and the gland. 7. The gear hole self-centering ball clamp according to claims 1 and 2, characterized in that a stop rod is fixed on the top of the clamp mandrel. 8. The gland according to claim 1, 2, characterized in that a vertical upward bolt is installed on the gland. 9. The gear hole self-centering ball fixture according to any one of claims 1-8, characterized in that: the number of gear blanks is 1-8 pieces, and when there are more than two gear blanks, the gear blanks are placed on the clamp mandrel Superimposed together, each piece of gear blank corresponds to a ball ring and a centering tapered sleeve one by one.

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