KR100607866B1 - Method of working worm gear by general lathe turning - Google Patents

Abstract

The present invention is to provide a method for processing a worm gear using a universal lathe capable of processing a worm having a variety of lead values or a worm having a large lead value using a universal lathe.

The worm processing method according to the present invention is replaced with change gears determined from the basic conditions (lead value, worm string number, pitch circle diameter, module, etc.) of the worm to be machined, and the torsion angle of the worm is It is characterized by turning the bite at the same angle to be mounted on a tool post for turning.

The present invention can not only process the worms, which were made by conventional hobbing machines or grinding processes, but also general general-purpose lathes, and in particular, non-standard screwing is also possible.

Preset worm gear, turning, bite slope, conversion gear group

Description

Method of machining worm gear using general purpose lathe {METHOD OF WORKING WORM GEAR BY GENERAL LATHE TURNING}             

1 is an explanatory diagram showing a machining state of a worm gear by a lathe;

2 is an explanatory view showing a state in which the shank of the tool according to the present invention is machined according to the twist angle of the worm gear;

    <Description of the symbols for the main parts of the drawings>

1: workpiece 11: lathe spindle

12: Feed screw 13: Tool stand

14: Byte 14a: Byte Tip

14b: shank

The present invention is to provide a method of processing a worm gear using a general-purpose lathe that can be processed by using a general-purpose lathe in particular the worm having a variety of lead value, the worm having a large lead value.

In general, the machining of the gear including the worm gear is usually cut by a hobbing machine, but unlike the general hobbing machine for worm gears, the worm gear needs to be equipped with a transfer equipment for transferring a tool post. It is a fact that there is a problem such as lowering and the production cost is increased because the equipment itself is expensive.

Accordingly, in the case of worm processing with a small lead value, the machining is sometimes performed by a lathe. Even in this case, due to the characteristics of the lathe in which the lead value is determined according to the ratio of the rotational speed of the lathe spindle to the feed rate of the tool bar, the machining is performed. If the lead (or pitch) of the worm is not standardized, it is very difficult to control the rotational speed ratio of the spindle and the feed screw. .

Of course, in the case of using a CNC lathe instead of a general general lathe, the above limitations of the general lathe can be solved to some extent, but in the case of a worm having a large lead value, machining is difficult, and a dedicated jig for worm processing is provided. Not only must be equipped, but the price of the CNC automatic lathe is very expensive and difficult to purchase easily, and therefore, it is difficult to apply in a small workplace because it naturally leads to an increase in manufacturing cost due to the purchase of expensive equipment.

In addition, as pointed out above, when machining using a hobbing machine, since the worm cannot be processed by the mounting structure of the tool stand for general gear processing, the dedicated tool stand for worm processing must be removed after completely removing the existing tool stand. There is a tremendous inconvenience that needs to be reinstalled.

The present invention has been made in order to solve the above-mentioned conventional problems, a general-purpose lathe that can produce a variety of non-standard worms, worms with a large lead value, as well as non-standard screws even by using a general-purpose general purpose lathe. It is an object to provide a worm processing method using.

Moreover, an object of this invention is to provide the worm processing method using the general-purpose lathe which can improve the processing precision in turning a tooth of a worm.

In order to achieve the above object, the worm processing method according to the present invention is replaced with change gears determined from the basic conditions of the worm to be processed (lead value, number of worms, pitch circle diameter, module, etc.). It is characterized in that for mounting, turning and tilting the bite at the same angle as the torsion angle of the worm, mounted on the tool bar for turning.

Hereinafter, described in detail by the accompanying drawings of the present invention.

1 is a state diagram schematically showing a worm machining state by a general-purpose lathe, Figure 2 is a state in which the shank is processed to incline the bite in the machining direction according to the torsion angle of the worm gear in the machining method according to the present invention It is explanatory drawing which shows the.

In the worm processing method using a general-purpose lathe according to an embodiment of the present invention shown in FIGS. 1 and 2, first, consecutive values are listed based on at least four decimal places, and the values are assumed as pitch values. A preset step (a) of setting the most optimal conversion gear group and setting it as a list or constructing a DB to set an optimal conversion gear group for each numerical value; A pitch value calculating step (b) of calculating a pitch value from the basic condition value information of the worm to be processed; Based on the 'optimal conversion gear group for each value' information set in step (a), the conversion gear group corresponding to the numerical value closest to the pitch value calculated in step (b) is applied to the universal lathe. An installation step (c); A tool manufacturing step (d) of manufacturing a processing tool by calculating a processing error, a pressure angle, etc. from the basic condition value information of the worm to be processed; A tool angle adjustment step (e) of calculating the twist angle of the worm thread and machining the shank of the bite according to the angle; It characterized in that the processing performed step (f) to perform the machining by mounting the tool on the tool bar according to the set conditions.

In the above embodiment, when the basic condition value information of the worm to be processed is set on the basis of the perpendicular angle, the processing condition conversion step (c ') of converting and calculating on the basis of the axis angle is calculated and the conversion gear installation step (c). It may be further included between the tool manufacturing step (d). Since worms are generally processed by hobbing machines, it is almost always suggested that the processing conditions of the "height angle" standard are suggested for the processing method of the hobbing machine.

The most important and difficult step in the present invention is a preset step (a) of setting an optimum conversion gear group for each numerical value, and in order to minimize the processing error by selecting the conversion gear group most optimal for the numerical value of each pitch value. Therefore, it is essential to determine the optimal conversion values in advance for each and every value based on at least three decimal places. As shown in Table 1, in the embodiment of the present invention, the pitch values that can be processed by each conversion difference group are calculated to six digits or less after the decimal point, and are presented based on the pitch values. As shown in Table 1, in some cases, the same pitch value (p = 1.284722) can be obtained even if a different conversion gear group is selected.

As shown in Table 1, the conversion gear group according to the present invention is set between the number of teeth of the spindle drive gear (a) and the feed screw drive gear (b) as well as between the two gears (a) and (b) in some cases. It is important to set a more precise pitch value up to one thousandth of a unit by differently configuring the tooth ratio of the idle gears (c) and (d) to be installed in the. For example, the number of teeth of the idle gear c is 125, the number of teeth of the idle gear d rotated on the same rotational axis is 126, or even pitch values obtained by vice versa. Clean up so you can.

In addition, general general lathes are equipped with adjustment levers for finely adjusting the feedrate of the tool bar in stages. When the pitch values obtained according to each stage of the control levers are also arranged, the pitch value can be more precise. Can be.

In this way, a group of conversion values (i.e., set at a value equal to or closest to the pitch value (corresponding to step (b)) calculated by a simple calculation using the basic condition value information of the product to be processed) , The position of each of the conversion levers, the number of teeth of the gear (a), the number of teeth of the gear (b), the difference between the number of teeth of the idle gear (c) and the gear (d) is immediately identified and mounted on the universal lathe (step (c) If applicable).

That is, since the lead value (the pitch value multiplied by the number of lines of the worm) to be machined is determined according to the ratio of the rotational speed of the lathe spindle to the feed rate of the tool bar, the steps (b) and (c) If the lead value or pitch value of the worm to be machined is not standardized, it is a method of setting the ratio of the rotational speed of the spindle and the feed screw to the pitch value to be machined.

For the detailed description of the present invention, the basic conditions of the object to be processed will be described in detail by way of examples according to the present invention.

Assuming that the "optimum value conversion group for each numerical value" as shown in Table 1 is set by step (a), and given the basic conditions according to the worm's perpendicular angle standard to be processed,

Warhammer's End Circle: φ5.2264 Worm's Rim: φ3.4414

Pitch circle diameter: φ4.6614 Lead angle (α): 5 ° 01'16.42 ″

Pressure angle: 20 ° 04′15.27 ″

Under these basic conditions, the lead value calculating step (b)

Lead value (ℓ) = π × pitch circle diameter × tan α = 1.28420

Is calculated as

"Pitch ( p ) = number of lines of lead / warm"

If the one-line worm is the same pitch and lead,

In the case of a two-line worm, the pitch value is 0.64210.

The next step is to set the conversion gear group corresponding to the value closest to the calculated pitch value and apply it to the universal lathe (c), which is the closest to the calculated pitch value 1.28420 in the list table shown in Table 1. Check that the value is 1.284640, the number of teeth of gear (a) is set to 50, the number of teeth of gear (b) is set to 54, and the position of each lever is set to 'I-BD-8'. By turning and turning, it is possible to obtain a rotation ratio of the spindle / transfer screw in accordance with the calculated lead value.

[Table 1] Preset list example of conversion gear group and pitch value

pitch LEVER a b CD . . . . . . . . . . 1.281543 I-AD-8 30 66 I 1.281545 I-BD-5 36 50 - 1.281968 I-BD-8 55 60 - 1.281969 I-BD-6 55 70 - 1.282050 M-BD-5 36 60 I 1.284640 I-BD-8 50 54 D 1.284720 M-AD-1 30 72 - 1.284721 M-BD-4 36 54 - 1.284722 M-BD-1 50 60 - 1.284722 M-BD-1 42 50 D 1.286116 I-BD-7 56 66 I 1.288391 M-BD-7 36 70 - . . . . . . . . . . . . . . .

In Table 1, the item 'LEVER' indicates the setting direction of the operating lever of the power transmission unit for transmitting power to the main shaft and the feed screw, divided into three parts. The first part is divided into "I" which indicates the lever position for processing in inches and the "M" which indicates the lever position for processing in metric units, and the second part is a lever for selecting a transmission gear of the power transmission unit. The position of is shown in the A direction (AD) or B direction (BD), the last part is to indicate the position of the feed speed control lever provided in the tool bar. In addition, the item 'cd' means the number of teeth of the idle gear (c) and the gear (d), I is the number of teeth of the gear (d) than the gear (c) is the initial letter of Increase, D Denotes a case where the number of teeth of the gear c is larger than that of the gear d.

Of course, as described above, when the basic condition value information of the worm to be processed is set on the right angle basis, it is required to go through the processing condition conversion step (c ') of converting the calculation to the axis angle standard for lathe machining. The reason for this is that the machining of the worm by the lathe is performed on the basis of the axis angle. The formula for converting the values of the perpendicular angle to the axial angle is known in general mechanical design engineering, and thus description thereof will be omitted.

In the next step, in the tool angle adjustment step (d), the angle (torsion angle) formed between the axially perpendicular line of the worm gear and the tooth surface of the worm gear in the pitch circle is calculated and the shank of the bite is machined according to the angle. ,

In order to incline the tool in the tool bar feed direction by the lead angle α of the worm, the shank of the tool is machined as shown in FIG. 1 and then fixed to the tool bar as a bolt. The inclination of the angle of the tool in the worm processing direction is intended to increase the precision of the cutting surface while preventing the cutting worm tooth from interfering with the bite of the tool.

Generally, if the lead angle of the worm is less than 4 °, no problem occurs even if the tool angle is not tilted.However, if the lead angle exceeds 5 °, the machining should be performed with the tool angle tilted by the lead angle. It is desirable to make it.

By going through these steps, it is possible to precisely process non-standard worms even on general-purpose lathes.

At this time, if the number of strings of the worm is 2 or more, select the conversion gear group corresponding to the pitch value = 0.64210, and then perform the machining. Then, remove the workpiece by loosening the chuck of the spindle and invert the workpiece to 180 ° and fix it again. The processing performed step (f) is passed.

For example, suppose the worm has 3 lines.

Pitch value is calculated by calculating the pitch value = lead ÷ 3, and the machining is performed by selecting the conversion gear group corresponding to this value, and then the outer diameter of the workpiece is divided into 1/3 equal parts at intervals of 120 °. By going through three machining steps (f), the desired worm is processed. The method of dividing the workpiece at equal intervals and fixing the workpiece to the chuck of the main shaft is generally well known technique and thus will be omitted in the detailed description of the present invention.

The detailed description of the invention has been described with reference to specific embodiments of the invention as examples, but the invention is not limited thereto, and one having ordinary skill in the art to which the invention pertains without departing from the concept of the invention. Modification or modification of the invention in various forms by the ruler is of course included in the concept of the present invention.

As described above, the worm processing method using the general-purpose lathe according to the present invention can process the worm, which was performed only by a hobbing machine or grinding processing for gear processing, even in a general-purpose general-purpose lathe, thereby increasing productivity and drastically reducing production costs. In particular, non-standard worm gears, particularly worms with large lead values and non-standard threading, are also possible, which is a very useful invention in the machining industry.

In particular, the machining method according to the present invention enables precise machining of worm gears with a lead or pitch of at least 1/1000 units.

Claims (1)

In the cutting method of the worm gear, List the consecutive values based on at least 3 decimal places and set the most optimal conversion gear group by assuming that each value is a pitch value, create a list of them, or build a DB to optimize each numerical value. A preset step (a) of setting a conversion gear group; A pitch value calculating step (b) of calculating a pitch value of the reference axis angle from the basic condition value information of the worm to be processed; Based on the 'optimal conversion gear group for each value' information set in step (a), the conversion gear group corresponding to the numerical value closest to the pitch value calculated in step (b) is applied to the universal lathe. An installation step (c); A tool manufacturing step (d) of manufacturing a tip of a bite by calculating a machining error, a pressure angle, and the like based on the axial angle from the basic condition value information of the worm to be processed; Tool angle adjustment step of machining the inclined upper and lower surfaces of the bite shank so that the tip of the bite is inclined in the feed direction of the tool bar by the angle α formed by the tooth surface and the normal line of the axial gear. (e); And a machining performing step (f) of mounting the bite to a tool post according to the set condition.

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