JP4728200B2 - Hob cutter and gear cutting method using the hob cutter - Google Patents

Description

The present invention relates to a gear tooth cutting method using the hob cutter and the hob cutter. In particular, use of the hob cutter for forming two different gears by cutting using a hob cutter and the hob cutter having a cutting tooth with a contour structure involute (involute) gear teeth and the gear tooth root clearance region of curvilinear structures The present invention relates to a gear tooth cutting method.

Known gear cutting is to cut the tooth profile by cutting movement of the work block and a cutter, first semifinished forming teeth formed by hob cutter of the worm-shaped, and processed further to gear teeth having a gear wheel shape gear Complete the wheel.
As shown in FIG. 1 showing a known gear outer mold, the gear 10 includes a disk-shaped main body 11 and gear teeth 12 are formed on the outer peripheral edge of the main body 11. Between the two gear teeth 12 with the gear tooth 13, molding of the gear tooth 13 is primarily due to two steps of perforating the gear formed by the drill.
As shown in FIG. 2, first, drilling 131 is performed at a predetermined position on the main body 11. The position and size of the drilling 131 are determined according to the actual gear specifications. After step drilled hole with a drill of the body 11, cutting teeth in accordance with involute route L1, L2 of the engagement of gears symmetrically drilling 131 around both sides by the drill by a hob cutter (not shown). Thus, the side 121 of the gear teeth 12 is formed, and the drilling 131 by the drill achieves the gear tooth root 123 clearance effect.
The main purposes of clearance are the following two points.
(1) When fabricating a sawtooth section (SERRATION) on the gear, to prevent the saw teeth cutter strikes the gear body in the saw-tooth section.
(2) Provide a space to eliminate cutting waste when the hob cutter cuts the gear .

However, since the known manufacturing process is performed in two steps, drilling and gear tooth cutting, the following drawbacks exist.
1. Since the diameter d1 of the drilled hole 131 is larger than the gear tooth 12 and the gear root interval distance d2, the gear tooth 12 forms a thin neck 122, but the presence of the neck 122 reduces the strength of the gear tooth 12. It is easy to break at the position of the neck 122.
2. When the main body 11 is completely drilled and is set on the gear tooth cutting machine, the gear tooth cutting cannot be performed accurately unless the positioning is performed again.
3. Since it is necessary to install a drilling machine base and a tooth cutting machine base with a drill, the equipment cost becomes high and more space is required.
4. Since the volume of the main body 11 is large and heavy, it is very inconvenient to carry it up and down between the drilling machine base and the tooth cutting machine base with a drill. There is a risk that.
To solve the above problem, a gear 14 (see FIG. 3) with two different curved contours 141, 142 tooth profile is designed to achieve the effect of gear tooth root clearance by the clearance area 143 formed by the curve 142. However, since the gear shown in FIG. 3 is known in the art and mainly performs two tooth cutting operations to achieve tooth profile formation of two different curves 141 and 142, such a manufacturing process is performed in the machining process. Cost and labor consumption.
JP 2005-59163 A JP 2005-66706 A

The known structure has the following drawbacks.
That is, since the manufacturing is performed in two steps, the formed thin neck is fragile and easily torn, and tooth cutting cannot be performed accurately unless the positioning is performed again. Furthermore, since two types of equipment are required, the cost becomes high, the space is increased, and the main body is large and heavy. Therefore, the vertical transportation between the two machine tools is inconvenient, and labor and time are wasted. There is a risk of damaging your body.
The new manufacturing process that solves the above problem also wastes time in the machining process, leading to consumption of production costs and manpower.
The present invention provides a method of gear teeth that uses hob cutter and the hob cutter and the above-mentioned problems with the structure.

To solve the above problems, the present invention provides a method of gear teeth that uses hob cutter and the hob cutter below.
Provides a method of gear teeth that uses hob cutter and the hob cutter, the hob has a structure with two different contours on the cutting teeth, two to one machining the work block on at the same time Achieve tooth profile contouring with different curves,
Further provides a method of gear teeth that uses hob cutter and the hob cutter, machining a gear using the hob to form a cutting tooth with two different contour structure, once the clearance area of the gear Achieve the purpose of molding with
Ie it comprises hob body, a plurality of cutting teeth,
The hob body comprises a plurality of chip discharge groove,
The plurality of cutting teeth are formed on the hob body, and are positioned on both sides of the cutting waste discharging groove, and the cutting teeth further include a first tooth portion and a second tooth portion,
The first tooth portion is formed on the hob body, and the first tooth portion can form an involute curve contour of a gear on one work block, and the second tooth portion is A clearance curve contour of the gear can be formed on the work block,
It said second tooth portion is formed on said first teeth,
The curved contour is a contour in which the second tooth portion forms an undercut,
The curved contour is an involute curved contour;
In該被processing block gear, area curve contours formed a clearance area of said gears,
Furthermore, it provides a hobbing method, it consists of the following steps,
First tooth portion is formed on the hob body, said first teeth to form one involute on the processed block (involute) curved contour, and the second tooth portion on該被processing block Forming a clearance curve contour,
The second tooth is formed on the first tooth;
The curved contour is a contour in which the second tooth portion forms an undercut ,
The curved contour is an involute curved contour;
In該被processing block gear, area curve contour forms are clearance area of the gear,
Additionally it further provides a method of forming a sort of gear, which consists of the following steps,
Providing a workpiece body, setting a root of an involute curve contour and a route of a clearance area contour intersecting each other at a specified position point on the workpiece body;
Providing hob cutter, which comprises a plurality of cutting teeth,該切Kezuha further comprises a first tooth portion and a second tooth portion, the hob cutter rotary cutting off relative to the workpiece body in accordance cutting root Forming a contour with an involute curve with the first tooth, and forming a gear with the clearance area contour with the second tooth;
The involute (involute) routing scheme routes and the clearance area profile of the contoured is even the following steps,
First determine the involute (involute) curve contour of the root, and sets the specified location points in the involute (involute) on the curve contour of the root, and form a tooth thickness of the specified location points, the designated position set point pressure angle,-out further the diameter of the specified location points, the pressure angle, the tooth thickness, draw a line determined the clearance area profile by helix angle,
The clearance area contour is a contour where the second tooth portion forms an undercut;
The clearance area profile is a method of gear teeth that uses hob cutter and該Ho Bukatta, characterized in that the involute (involute) curve contour.

As in the structural features of the present invention and the embodiments described above, the present invention uses a hob with a special tooth profile, and can produce a gear with two different curved contours by a single rotary cutting. It is practically effective and has a very high utility value in the industry.

As shown in FIG. 4 is a hob perspective view of the present invention, the hob cutter 2 consists hob body 20 and a plurality of cutting teeth 22.
The hob body 20 includes a plurality of cutting waste discharge grooves 21.
The plurality of cutting teeth 22 are formed on the hob body 20 and are located on both sides of the cutting waste discharge groove 21.
As shown in FIG. 5, which is a cutting tooth profile contour instruction diagram of the hob of the present invention, the cutting tooth 22 further includes a first tooth portion 220 and a second tooth portion 221.
The first tooth portion 220 is formed on the hob body 20, and the first tooth portion 220 forms an extended (involute) curved contour on one work block. The second tooth portion 221 is formed above the first tooth portion 220 and forms a curved contour on the block to be processed.
The curved contour is an extended (involute) curved contour or an undercut contour formed by further deeply cutting the block to be processed by the second tooth portion 221. The cutting waste discharge groove forms a direction intersecting the axis of the hob main body, and the hob is a cutting waste discharge groove having a straight cutting waste discharge groove or a spiral angle according to the intersecting direction.

Utilizing the hob 2, the present invention further provides a method of gear production. As shown in FIG. 6 is a best embodiment the process instruction diagram of a forming method of the present invention the gear, the method 3 include the following steps.
First, in step 30, a workpiece body is prepared (provided).
Next, in step 31, the tooth profile of the gear is determined, and a route of an involute curve and a route of a clearance area contour intersecting each other at a specified position point on the workpiece body are set. The clearance area profile selects involute (involute) curved contour or deeper undercut cutting edge.
As shown in FIG. 7 which is a processing route contour instruction diagram on the workpiece main body, an extension (involute) curve L5 and a curved contour L6 are set for the workpiece main body 4. The curved contour L6 is a contour formed by deeper cutting during hobbing in the present embodiment. The involute curve L5 and the curve contour L6 intersect each other at the designated position point P. Position of the involute (involute) curve L5 represents the gear teeth and areas intermeshing be processed blocks of gears at the time of molding the future gear, curve contours L6 represents a clearance area profile.

Method of determining the involute (involute) curves L5 and curve contour L6 are as follows. 7, first set the first cutting root of the first primary open line L5 root, then sets the designated position point P on the involute (involute) curve L5. Method of determining the involute (involute) curve in accordance with the tooth profile of the gear to determine the base circle onto the workpiece body 4, resulting in the involute (involute) curve L5 on the basis of the base circle followed. Since the method of the involute curve in which the base circle is generated is a known technique, it will not be described in detail here.
In addition, the principle of determining the designated position point P is determined based on the necessity of the clearance area of the gear . In general, the designated position point P is usually located below the starting point (Starting Active profile, SAP) of the involute curve . The SAP location is determined based on the needs of the standard. This is known to those skilled in the term, and is not described in detail, but is based on the following equation.
T = 2r ((T1 / 2R1) + invψ1-invψ)
T = tooth thickness at specified point
r = specified point radius
T1 = tooth thickness at the pitch circle position
R1 = Pitch circle radius
invψ1 = pitch circle vector angle;
invψ = specified point vector angle;
In this way, the tooth thickness T of P at the designated position point can be obtained. Next, the pressure angle ψ of the designated position point P is set, the diameter OD _i and the spiral angle HA _i of the designated position point P are set, and the absolute value Mn _i of the second tooth portion 221 is determined based on the following equation: To do.
Mn _i = OD _i Cos (HA _i ) / Z
Z = gearwheel teeth in this way, it is possible to draw a curve contour L6 determined pressure angle [psi, the tooth thickness T and the absolute value Mn _i.

As shown in FIG. 6 again, the next hob cutter of Figure 4 at step 32, performs processing based on the arrangement of Figure 8.
In FIG. 8, the central axis 23 of the hob 2 and the central axis 40 of the workpiece body 4 are in an intersecting relationship, and if the intersecting angle (that is, the two axes 23, 40 are projected onto a plane). When the angle between the two shafts 23 and 40 is 90 degrees, the machined gear has no spiral angle. Conversely, if it is not 90 degrees, the gear has a helical angle.
As further shown in FIG. 5 again, first tooth portion 220 and the second tooth portion 221 of the cutting teeth 22 of the hob, said involute (involute) curve L5, configured to correspond to the curved contour L6 tooth Contour. Subsequently, in step 33, the hob performs rotational cutting on the workpiece main body according to a cutting route, and the first and second tooth portions have the two intersecting extension (involute) curved outer contours. Form a gear with a curved contour. Here, the cutting route is a play line route. The involute (involute) contoured outline contour of said first toothed portion is processed, curve contours are contours said second toothed portion is formed workpiece body was cut deeper. In addition, the curved contour is also an involute curved contour, and the design method is determined by the equation of the tooth thickness and the absolute value.

As shown in FIG. 9 hob cutter of the present invention is a cutting root view when processing a workpiece body, rack cutting teeth 22 of the hob forms (rack) are shown in Figure 9 (Figure 1 Only show species). Further, as shown in FIG. 8, when the hob 2 rotates, the cutting teeth on the hob 2 form the cutting route shown in FIG. In the process of rotational cutting of the hob, the cutting route shown in FIG. 9 of the rack formed by the cutting teeth is the one-time operation of the gear tooth profile contour formed by the involute curve L5 and the curved contour L6 in FIG. It is formed by a cutting process.
Further, the cutting route is the play line route, and the contour of the play line L7 is formed at the end of the curved contour. Finally, the gear shown in FIG. 10 is formed by the above processing operation.

It is a gear instruction | indication figure of a well-known technique. It is a gear tooth profile and root clearance area instruction | indication figure of a prior art. FIG. 3 is an illustration of a known structure with different curvilinear gear teeth and root clearance areas. A hob cutter solid instruction diagram of the present invention. It is a cutting tooth profile outline directions figure of the hob of the present invention. It is a process instruction | indication figure of the Example of the optimal gear formation method of this invention. It is a process route outline directions figure on the work body. It is a relative position instruction | indication figure of the hob of this invention, and a workpiece main body. FIG. 3 is a route diagram when performing hobbing on the workpiece body in the present invention. FIG. 4 is an instruction diagram for forming a gear by performing hobbing on the workpiece body in the present invention.

10 gear
11 Disc type body
12 gear teeth
121 side
122 Neck
123 gear tooth root
13 gear tooth gap
131 Drilling holes
14 gear
141 Involute curve
142 Curve contour
143 Clearance area
d1 diameter
d2 gear tooth root distance
L1, L2 extension (involute) curve route
2 Hob
20 Hob body
21 Cutting waste discharge groove
22 Cutting teeth
220 First tooth
221 Second tooth
23 Center axis
3Gear formation method
30-33 process
4 Workpiece body
40 central axis
L5 extension (involute) curve
L6 Curve contour
L7 Play Line
P Specified position point

Claims (3)

In the gear tooth cutting method,
Set the route of the first stretched line contour and the route of the clearance area contour that intersect each other at the specified position point on the workpiece body,
A plurality of cutting teeth are provided, and the cutting teeth further prepare a hob cutter including a first tooth portion and a second tooth portion formed thereon,
The hob cutter performs rotational cutting on the workpiece body according to the cutting route, forms a contour with a gear tooth extension line by the first tooth portion, and the clearance by the second tooth portion. A gear tooth cutting method using a hob cutter, characterized in that a gear tooth having an area contour is formed. In setting the route of the extension line contour and the clearance area contour,
First, determine the route of the extended line contour,
Set the designated position point on the route of the stretched line contour,
The tooth thickness of the designated position point and the pressure angle of the designated position point are set, and the route of the clearance area contour is obtained from the diameter, pressure angle, tooth thickness, and spiral angle at the designated position point. A gear tooth cutting method using the described hob cutter. The gear by a hob cutter according to claim 1, wherein the clearance area contour is either a contour formed by undercutting the second tooth portion or an extended line contour formed by the second tooth portion. Teeth cutting method.

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