CN100506478C - Four-Axis CNC Ellipsoidal and Spherical Hob Relief Grinding Machine - Google Patents

Abstract

The invention discloses a 4-axis nc relief grinding machine tool for ellipsoidal and spherical hobs, which is characterized in that: a machine bed(3) is provided with an arc adjusting plate(11) whose position can be adjusted and a rotary plate(19) that can rotate around a rotary shaft(18) fixed on the arc adjusting plate(11).The rotary plate(19) is sequentially provided with a radial feeding knife frame(22), a tangential feeding knife frame(15) and a cutter from the lower part to the higher part. The rotary shaft (18) is perpendicular to the central lines of a spindle box (1) and a tailstock (2). An arc rolling guiding rail (23) is arranged between the rotary plate (19) and the arc adjusting plate (11). The lower parts of the radial feeding knife frame (22) and the tangential feeding knife frame (15) are respectively provided with a straight line rolling guiding rail (21). With the proposal adopted, the special machine tool for processing spherical and ellipsoidal internal gear hobs is provided, which solves the problems that the cutters of large diameters are difficult to be processed with difficult processing and low precision.

Description

Four-Axis CNC Ellipsoidal and Spherical Hob Relief Grinding Machine

technical field

The invention relates to a four-axis numerical control ellipsoidal and spherical hob relief grinding machine tool, in particular to a machine tool for processing ellipsoidal and spherical internal gear hobs.

technical background

Gear shaping is currently the most commonly used method for machining internal gears based on the generating principle. Spherical hob is designed based on the principle of machining internal gear with gear shaping cutter. It is a kind of generating tool. One hob can process large straight or helical internal gears with the same modulus but different numbers of teeth. The hob is After the shovel tooth structure is reground, the tooth shape of the processed workpiece remains unchanged, and it has the advantages of high machining accuracy, long service life and good versatility. The spherical hob is currently the most ideal tool among hobbing tools for large internal gears. But there is no special-purpose machine tool for processing spherical or ellipsoidal helicoids, especially large-diameter machine tools with a tool diameter of more than 400 millimeters, and there are no machine tools for relief grinding and multi-axis linkage.

The last and most critical process of manufacturing ellipsoidal hobs and spherical hobs is the relief grinding of hobs. It is impossible to use the modified shovel tooth lathe used in the manufacture of spherical hobs to relieve grinding of ellipsoidal hobs up. Because the position of the center of rotation of the shovel tooth lathe tool post is fixed and cannot be moved, it just intersects perpendicular to the center line of the machine tool spindle, so it can only process spherical hobs. At the same time, ordinary shovel tooth lathes are completely mechanically driven, and cannot be corrected when the normal pitch of the hob is out of tolerance.

Contents of the invention

In order to solve the problems of difficulty in processing spherical and ellipsoidal hobs, low precision, and difficult processing of large-diameter tools that are common in machine tools, the present invention provides a new type of four-axis numerically controlled ellipsoidal and spherical hob Relief grinding machine, which can effectively solve the above problems.

A four-axis CNC ellipsoidal and spherical hob relief grinding machine, including a headstock, a tailstock and a bed, is characterized in that: the bed is equipped with an adjustable arc plate and can be fixed around the arc The rotating plate on which the rotating shaft on the plate rotates. The radial feed tool rest, the tangential feeding tool rest and the cutting tool are installed on the rotating plate in sequence from low to high; the rotating shaft is perpendicular to the spindle box and the tail The center line of the seat, the arc rolling guide rail is installed between the rotating plate and the arc adjusting plate, and the linear rolling guide rail is respectively installed under the radial feed tool holder and the tangential feed tool holder; the rotating plate is installed There is a worm gear, the first servo motor is installed on the arc adjusting plate, the first servo motor is connected with the worm through a coupling, and the worm is meshed with the worm gear; there is a gear in the headstock, which and the second servo motor pass through The first synchronous toothed belt is connected; the radial feed tool post is connected with the first ball screw, and the first ball screw and the third servo motor are connected through the second synchronous toothed belt; the tangential feed The knife rest is connected with the second ball screw, and the second ball screw is connected with the fourth servo motor through the third synchronous toothed belt.

Adopting this scheme solves the problem of manufacturing spherical and ellipsoidal hobs. At the same time, due to the use of CNC relief grinding, the theoretical tooth pitch error of the hob is corrected, and the manufacturing accuracy of the hob is improved. Because the center height of the machine tool is raised and the radius of rotation of the rotary tool holder is increased, it can meet all current requirements. Manufacturing requirements for hobs required for modular internal gear machining.

Description of drawings

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings.

Figure 1 is a front view of a four-axis CNC ellipsoidal and spherical hob relief grinding machine;

Figure 2 is a top view of a four-axis CNC ellipsoidal and spherical hob relief grinder;

Fig. 3 is the left view of the four-axis CNC ellipsoidal and spherical hob relief grinding machine;

Fig. 4 is a cross-sectional view of an ellipsoidal internal gear hob.

Detailed ways

In order to solve the problem of manufacturing spherical and ellipsoidal hobs, the present invention develops a processing device for ellipsoidal hobs—a four-axis CNC ellipsoidal hob and spherical hob relief grinding machine, as shown in Figures 1, 2 and 3. It includes a headstock 1, a tailstock 2 and a bed 3, wherein the bed 3 is equipped with a position-adjustable arc regulating plate 11 and a rotating plate 19 that can rotate around a rotating shaft 18 fixed on the arc regulating plate 11, Radial feed tool holder 22, tangential feed tool holder 15 and cutting tool are installed on the rotating plate 19 from low to high; The guide rail 23 is supported, and the radial feed tool holder 22 and the tangential feed tool holder 15 are respectively supported by the linear rolling guide rail 21 . Rotating plate 19 is equipped with worm gear 7, and first servomotor 10 is installed on arc regulating plate 11, and first servomotor 10 drives worm screw 8 and worm gear 7 through coupling 9, and rotating plate 19 is rotated around rotating shaft 18. The main shaft is driven to rotate by the second servo motor 5 through the first synchronous toothed belt 4 and the gears in the main shaft box. The radial feed tool holder 22 is driven by the third servo motor 17 through the second synchronous toothed belt 16 and the first ball screw 20 to perform radial feed. The tangential feed tool holder 15 is driven by the fourth servo motor 13 through the third synchronous toothed belt 12 and the second ball screw 14 to perform tangential feed.

The main features of this machine tool are: it has a fan-shaped rotary tool rest that can move along the direction perpendicular to the center line of the main shaft, that is, the arc-adjusting plate. Its spiral line is the basic characteristic. On the rotary tool post is a radial feed tool post, above which is a tangential feed tool post. The above three tool holders are respectively driven by three servo motors.

When working, the hob blank is installed on the main shaft of the machine tool through the mandrel, and the right end is supported by the top of the tailstock 2. When the hob is installed, the axial position should be adjusted so that the middle line of the hob blank passes through the rotation center of the tool holder. Adjust the arc adjusting plate 11 so that the rotating shaft 18 on it moves to the distance from the center of the machine tool spindle to the L value in Figure 4, and then lock the arc adjusting plate 11. After the hob blank and each tool holder return to the initial position, the cutters installed on each tool holder feed and start to work, and their kinematic relationship is guaranteed by the numerical control system. The main shaft of the machine tool is driven by the second servo motor. When the main shaft of the machine tool rotates together with the hob to be processed, the tool post is driven by the first servo motor 10 and rotates around its center at a fixed ratio through the worm 8 and the worm wheel 7 to process an ellipsoid Helicoid. As the diameter of the ellipsoidal hob decreases, the helix angle of the hob increases, and the normal pitch error of the hob increases. The machine tool adopts four-axis numerical control. By changing the instantaneous angular velocity of the rotary tool holder, the tooth pitch of the hob is variable in the axial direction and the tooth pitch is equal in the normal direction, thereby reducing the theoretical error and improving the manufacturing accuracy of the hob. The radial and tangential feed tool holders 22, 15 of the machine tool can complete the radial and tangential relief grinding of the hob. During relief grinding, a shaped grinding wheel is used, and the axial profile of the grinding wheel is modified according to the axial tooth profile coordinates of the hob given in Figure 4.

Due to the completion of the whole process of hob relief grinding, the rotary tool holder has to reciprocate dozens of times. In order to avoid the influence of the gap between the worm and the worm wheel, each stroke is completed, all return to zero, and the next stroke starts again from zero. way to start.

This machine tool is designed to manufacture large modulus ellipsoidal and spherical hobs. Considering the actual needs of existing modulus 28 hobs, the center height of the machine tool is increased and the turning radius of the rotary tool holder can be increased. Manufacture hobs with a modulus of 30mm and a diameter of 600mm, which can meet the current manufacturing requirements of all hobs required for large modulus internal gear processing.

Claims (1)

1, a kind of four-shaft numerically controlled ellipsoidal and spherical hobbing cutter spade milling machine tool, comprise main spindle box (1), tailstock (2) and lathe bed (3), it is characterized in that: the adjustable accent arc plate (11) in position is installed on the described lathe bed (3) and can radial feed knife rest (22), tangential admission knife rest (15) and cutter be installed successively on the described rotor plate (19) from low to high around the rotor plate (19) that is fixed in turning cylinder (18) rotation of transferring on the arc plate (11); Described turning cylinder (18) is perpendicular to the center line of main spindle box (1) and tailstock (2), between rotor plate (19) and the accent arc plate (11) circular arc rolling guide (23) is installed, described radial feed knife rest (22) and tangential admission knife rest (15) below are separately installed with linear rolling track (21); Described rotor plate (19) is equipped with worm gear (7), and first servomotor (10) is installed on the described accent arc plate (11), and first servomotor (10) links to each other with worm screw (8) by shaft coupling (9), worm screw (8) and worm gear (7) engagement; Described main spindle box has gear in (1), and it is connected by first synchronous cog belt (4) with second servomotor (5); Described radial feed knife rest (22) is connected with first ball-screw (20), and first ball-screw (20) is connected by second synchronous cog belt (16) with the 3rd servomotor (17); Described tangential admission knife rest (15) is connected with second ball-screw (14), and second ball-screw (14) is connected by the 3rd synchronous cog belt (12) with the 4th servomotor (13).

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