CN110842281A

CN110842281A - Broaching broach integration of small-modulus internal gear

Info

Publication number: CN110842281A
Application number: CN201911289742.XA
Authority: CN
Inventors: 陈子彦; 何勤松; 潘骋鹄; 杨益波; 孙洪卫; 沈成栋
Original assignee: EST TOOLS Co Ltd
Current assignee: EST TOOLS Co Ltd
Priority date: 2019-12-16
Filing date: 2019-12-16
Publication date: 2020-02-28

Abstract

The invention relates to broach integration of a small-modulus internal gear, and discloses broach integration of the small-modulus internal gear, which comprises a mandril, a lower chuck, a flange plate, a workpiece, a broach and an upper chuck, and is characterized in that the lower chuck is provided with a lower jaw and a limit key; the flange plate is provided with anti-skid claws; the upper chuck is provided with an upper claw; the broaching tool is arranged into a rough-drawing part, a fine-drawing part, an upper chuck and a lower chuck which are arranged on a machine tool workbench, a workpiece is arranged on a flange plate, and the broaching tool axially penetrates through the workpiece clamped on the flange plate, so that the technical problem that the broaching precision, particularly the tooth form precision, of the small-modulus internal gear progressive process is difficult to guarantee can be effectively solved, and the broaching tool does not need to be changed greatly.

Description

Broaching broach integration of small-modulus internal gear

Technical Field

The invention relates to the technical field of broaching of internal gears, in particular to broaching and broaching integration of a small-modulus internal gear.

Background

Similar to the spline broaching process, the method has been widely used for broaching internal gears in recent years because of its advantages of high efficiency and low cost. Because the precision of the gear, especially the precision of the tooth form, is much higher than the spline, for example, by adopting the gradual forming broaching principle of the traditional spline broach, as shown in fig. 1 (a), the workpiece is self-positioned relative to the broach, on one hand, the straightness (or spiral line) of the whole tooth strengthening length of the broach and the straightness of a machine tool guide rail bring direct influence on the formation of the tooth form of the workpiece, the longer the cutting stroke of the broach is, the larger the influence is, on the other hand, the tooth side of the broach has a side clearance angle, the peripheral displacement between the workpiece and the broach can be caused by broaching vibration, especially, the deviation of the tooth form direction of the workpiece can be aggravated due to the fact that the workpiece has peripheral action and reaction force relative to the broach when the helical internal gear is broached. Therefore, the broaching tool for broaching the internal gear generally adopts a design structure combining gradual rough broaching and contour finish broaching, as shown in fig. 1(b), so as to avoid the technological limitation of the gradual broaching on the tooth profile precision of the workpiece. However, the same-profile broaching is the tooth side cutting, when the gear parameter is less than 1.0 modulus, the same-profile cutting mode cannot be realized because the tooth top of the small broaching tool with the tooth width is too sharp, the rigidity is not enough and the chip removal space is limited, and in addition, the manufacturing cost of the same-profile broaching tool is also very high. Therefore, the broaching of the internal gear with small modulus under the premise of meeting the precision is a great technical difficulty in the tool industry.

Disclosure of Invention

The invention provides broaching broach integration of a small-modulus internal gear, which effectively solves the technical problem that the broaching precision of the gradual process of the small-modulus internal gear is difficult to ensure without great change to broaching machine equipment by the integrated change of clamping and positioning of a broach and a workpiece and the optimization of the structural design of the broach in the implementation process of a broaching process.

The invention relates to a broaching broach assembly for a small-modulus internal gear, which is mainly composed of a top rod 1, a lower chuck 2 (comprising a lower claw 21 and a limit key 22), a flange 3 (comprising an anti-skid claw 31), a workpiece 4, a broach 5, an upper chuck 6 (comprising an upper claw 61) and the like except for a broaching machine, as shown in figure 2. The invention adopts a pull-up cutting mode, namely, the broaching tool 5 is axially fixed in the broaching process, and the worktable moves upwards to drive the workpiece 4 to finish the feed of the tooth-by-tooth cutting amount relative to the broaching tool. Compared with the traditional broaching process, the process system is additionally provided with the ejector rod 1 and the lower chuck limiting key 22, the broaching tool 5 is manufactured by adopting a rough and fine broaching subsection and a front handle flat structure design, and the flange 3 is provided with the anti-skid claw 31.

The broaching broach assembly of the small-modulus internal gear has the axial adjustable characteristic, the front handle of the broach 5 is inserted into the positioning hole of the lower chuck 2, the lower clamping jaw 21 is automatically inserted into the clamping groove of the handle part of the broach, and the ejector rod 1 is automatically pushed up to the end surface of the front handle of the broach 5, so that the lower clamping jaw 21 is always tightly attached to the traction surface of the front handle of the broach 5, the axial tool fleeing phenomenon caused by the influence of the cutting force change of the broach 5 in the process is avoided, and the axial position of the broach 5 is kept constant in the broaching process.

The invention relates to a broaching broach assembly of a small-modulus internal gear, wherein a lower chuck 2 is provided with one or more position limiting keys 22. As shown in fig. 3, the limiting key 22 is fixedly installed at the orifice of the lower chuck 2 by a screw and is matched and positioned with the front handle of the broach 5 in a flat manner, so that the broach 5 has no gap between the circumference direction and the lower chuck 2, particularly, when the helical internal gear is broached, the broach keeps synchronization with a circumference rotation process system, and is not influenced by circumferential acting force caused by the fact that the broach 5 has a blade inclination angle in the broaching process.

The invention relates to a broaching broach assembly for a small-modulus internal gear, wherein a flange plate 3 is provided with an anti-skid claw 31. As shown in fig. 4, a plurality of uniformly distributed key slots are designed on the upper end surface of the flange 3, the number of the key slots is specifically set according to the diameter of a workpiece, the cutting force and the like, the anti-skid claws 31 are fixed and installed in the key slots through screws and should be higher than the upper end surface of the flange 3, and the height difference H = 0.015-0.10 mm.

The invention relates to a broaching broach assembly of a small-modulus internal gear, wherein a plurality of triangular end face teeth are arranged on the upper end face of an anti-skid claw 31, the end face teeth are embedded into a workpiece positioning end face under the action of broaching force in the broaching process, and the embedding depth is the H size value, so that the circumferential displacement of a workpiece is prevented, and meanwhile, a workpiece reference surface is kept to be attached to the upper end face of a flange plate 3.

The invention relates to a broaching broach assembly of a small-modulus internal gear, wherein an anti-skid claw 31 is designed and manufactured by adopting hard alloy or hardened alloy tool steel materials so as to keep the rigidity and the wear resistance of the anti-skid claw.

The broaching broach 5 adopts the sectional design of a rough-drawing part and a fine-drawing part, as shown in fig. 5, the rough-drawing part 51 and the fine-drawing part 52 are both formed by gradual broaching, that is, two sections of teeth are both formed by cutting teeth one by one from the diameter size of a prefabricated hole in a mode of increasing the diameter tooth height.

The invention relates to a broaching broach assembly of a small-modulus internal gear, wherein a front handle part of a broach 5 is provided with one or more flat potentials.

The invention relates to a broaching broach assembly for a small-modulus internal gear, wherein a broach tooth side clearance angle of a rough broaching part 51 at the front section of a broach 5 is designed to be 1-1.5 degrees.

According to the broaching broach assembly for the internal gear with the small modulus, the rear section fine-drawing part 52 of the broach 5 is provided with a broach tooth side clearance angle of 0-0.5 degrees.

Drawings

Fig. 1 is a schematic view of two types of broaching workpiece forming.

Fig. 2 is a schematic drawing of the broach assembly of the present invention.

Fig. 3 is a schematic view of the structure of the broach integrated lower cartridge of the present invention.

Fig. 4 is a schematic view of the structure of the broach integrated flange plate of the present invention.

Fig. 5 is a schematic view of the broach integrated structure according to the present invention.

Detailed Description

In order to make the purpose and technical solution of the present invention more clear, the present invention will be further described with reference to the accompanying drawings, but not by way of limitation.

As shown in fig. 2, a workpiece 4 is placed on the anti-skid claw 31 of the flange 3, a broach 5 penetrates through the workpiece and the flange and is inserted into the lower chuck 2, the lower jaw 21 is automatically inserted into a clamping groove of a handle part of the broach, and the ejector rod 1 pushes up the end surface of a front handle of the broach and clamps the broach together with the limit key 22, so that the broach 5 is in gapless fit with the lower chuck in the axial direction and the circumferential direction in the cutting process.

The upper chuck 6 moves downwards and embraces the rear handle of the broach together with the upper clamping jaws 61, so that the whole broach is in a state of being vertical to the workbench; the workpiece 4 is now in the forward guiding position of the broach 5 by adjustment of the initial broaching stroke. When broaching is started, the machine tool workbench moves upwards to drive the workpiece 4 to enter the cutting part of the broaching tool 5, and under the action of cutting force, the triangle end face teeth of the anti-skidding claws 31 arranged on the flange plate 3 are embedded into the positioning surface of the workpiece 4, so that the positioning surface of the workpiece 4 is tightly attached to the mounting surface of the flange plate 3, and the workpiece 4 is circumferentially fixed and axially coaxial in the center of the system. In the whole broaching process, the broaching tool 5 and the workpiece 4 are always in a circumferentially fixed position except for cutting feed motion (the cutting feed is realized by the lifting of the broaching tool teeth, straight tooth broaching is in single linear motion, and helical tooth broaching is in equal-lead helical motion, namely, the synchronous rotation of the lower chuck 2 driving the broaching tool 5 is increased), so that the broaching precision deviation caused by circumferential displacement is avoided. And when the workpiece 4 is broached, the upper chuck 6 is loosened and moves upwards, the whole broach 5 penetrates through the workpiece 4, the worktable of the machine tool stops moving upwards, the workpiece 4 is moved out, the lower chuck 2 is loosened, the upper chuck 6 moves downwards to clamp the broach 5, the broach is lifted upwards to be separated from the worktable and the flange 3, and the workpiece is placed again and then enters the next round of broaching. In addition, the broaching tool 5 adopts a rough and finish drawing segmented design, particularly, a finish drawing segment adopts a large tooth lifting small side rear angle design because of small cutting amount, compared with a one-segment design method, the cutting stroke of the finally formed workpiece tooth shape is shortened by nearly 50 percent, and therefore, the cutting precision difference caused by machine tool performance errors such as the straightness of a machine tool guide rail is reduced by nearly half. By adopting the process method and the broach design structure, in the whole broaching process, the broach and the workpiece are always in a circumferentially fixed position except for cutting feed motion, and meanwhile, the broaching stroke for finally forming the tooth shape of the workpiece is shortened through the coarse and fine two-section broaching structure of the broach, so that the technical problem that the broaching precision, particularly the tooth shape precision, of the small-modulus internal gear progressive process is difficult to ensure is effectively solved, and the broaching machine does not need to be greatly changed.

Claims

1. A broaching broach assembly of a small-modulus internal gear comprises a mandril (1), a lower chuck (2), a flange plate (3), a workpiece (4), a broach (5) and an upper chuck (6), and is characterized in that the lower chuck (2) is provided with a lower clamping jaw (21) and a limit key (22); the flange plate (3) is provided with an anti-skid claw (31); the upper chuck (6) is provided with an upper claw (61); the broaching tool is arranged into a rough drawing part (51) and a fine drawing part (52), an upper chuck (6) and a lower chuck (2) are arranged on a machine tool workbench, a workpiece (4) is arranged on a flange plate (3), and a broaching tool (5) axially penetrates through the workpiece (4) clamped on the flange plate (3).

2. The broaching tool assembly for the internal gear with small modulus of elasticity of claim 1, wherein the mandril (1) is arranged to be adjusted up and down in the axial direction, and when the front handle of the broaching tool (5) is inserted into the lower chuck (2), the mandril (1) automatically jacks up.

3. The broaching tool assembly for internal gear with small module according to claim 1, wherein the lower chuck (2) is provided with one or more position limiting keys (22), and the limiting keys (22) are fixed at the hole of the lower chuck (2) by screws and are matched with the broaching tool (5) without clearance.

4. The broaching broach assembly for an internal gear with a small modulus of elasticity according to claim 1, wherein a plurality of key slots are uniformly formed on the upper end surface of the flange plate (3), and the number of the key slots is specifically set according to the diameter of a workpiece, the magnitude of cutting force and the like; the anti-skidding claw (31) is fixed and installed in the key groove through a screw, the height difference of the anti-skidding claw is set to be H = 0.015-0.10 mm and is higher than the upper end face of the flange plate (3).

5. The broaching assembly of an internal gear with small modulus of elasticity of claim 1, wherein the upper end face of the anti-slip claw (31) is provided with a plurality of triangular end face teeth, and the end face teeth are embedded into the positioning end face of the workpiece under the action of broaching force during broaching, wherein the embedding depth is H = 0.015-0.10 mm, so that the circumferential displacement of the workpiece is prevented, and meanwhile, the reference surface of the workpiece is kept to be attached to the upper end face of the flange plate (3).

6. The broaching tool assembly for internal gear with small modulus of elasticity of claim 1, wherein the anti-slip claw (31) is made of hard alloy or hardened alloy tool steel material, so as to ensure the rigidity and wear resistance of the anti-slip claw (31).

7. The broaching tool assembly for an internal gear with small modulus of elasticity as claimed in claim 1, wherein the rough-drawn part (51) and the fine-drawn part (52) are formed by gradual broaching, and two segments of tool teeth are formed by cutting from the diameter size of the prepared hole in a manner of ascending the diameter tooth.

8. The broaching broach assembly for an internal gear with a small modulus of elasticity according to claim 1, wherein the tooth flank angle of the front half-drawn portion (51) of the broach (5) is set to be between 1 ° and 1.5 °.

9. The broaching process method for the internal gear with small modulus of elasticity according to claim 1, wherein the tooth flank clearance angle of the rough-drawn part (52) at the rear section of the broaching tool (5) is set to be 0-0.5 °.

10. A broaching bit assembly for internal gear with small modulus of any of claims 1 to 9, characterized in that the front and rear shanks of the broaching bit (5) are formed in a flat shape with one or more surfaces.