JPH0558865B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a helical groove machining method using a machining center.

[Conventional technology]

Traditionally, a tool grinder was used to machine a helical groove in a cylindrical tool material. In a tool grinder, the grinding wheel head to which the grinding wheel is attached can rotate around a vertical axis, and the grinding wheel can be held at an angle equal to the helix angle of the groove relative to the tool material held horizontally. It is possible. Therefore, if the tool material is rotated around its axis while moving in the direction of its axis while maintaining this state,
Helical grooves can be easily ground simply by controlling two axes simultaneously.

By the way, machining centers have come to be used in many factories in recent years, and among these, horizontal machining centers have a main axis on which a processing tool is attached in a horizontal direction. This main shaft is configured to be movable in the vertical direction (Y-axis direction) and in the axial direction (Z-axis direction), but cannot rotate around the vertical axis. Therefore, when attempting to machine a helical groove in a cylindrical tool material using such a machining center, the tool material held on the table is rotated around the vertical axis (direction B), and the machining tool and It is necessary to match the inclination angle of the groove to the helix angle of the groove.

However, when holding the tool material at an angle in this way, the tool material is not only rotated around its axis (direction C) and fed in the direction of its axis, as is the case when machining with a tool grinder. , it is not possible to machine helical grooves. This is because the bed on which the table that holds the tool material is placed cannot move in the axial direction of the tool material, but only in the direction perpendicular to the main axis (X-axis direction). This is because the material is displaced not only in the X-axis direction but also in the Z-axis direction. However, since tool grinders are expensive, it would be very economical to machine helical grooves with a horizontal machining center, and such a processing method has been desired for some time.

[Problem to be solved by the invention]

This invention was made in view of the above circumstances, and its purpose is to propose a processing method that can form helical grooves in a cylindrical material using a machining center. .

Another object of the present invention is to propose a processing method that can easily and economically form helical grooves in a cylindrical material.

[Means to solve the problem]

This invention comprises: a main shaft installed horizontally and movable vertically and in the direction of its axis; a bed for mounting a rotating tool such as a grinding wheel; and a bed for placing a workpiece that moves in a direction perpendicular to the main shaft. and a machining center equipped with a workpiece holding device that is installed on the bed and is rotatable around a vertical axis in a horizontal plane, and also allows the held workpiece material to be rotated around its axis. A processing method for forming a helical groove with a torsion angle θ and a lead L in a cylindrical material, comprising: holding the cylindrical material horizontally in the work holding device; and forming a helical groove with a torsion angle θ. tilting the cylindrical material in a horizontal plane with respect to a rotary tool attached to the main shaft so as to form a groove; , a step of adjusting the positional relationship between the main shaft and the cylindrical material, and a step of processing the cylindrical material with the rotary tool while moving in a horizontal direction perpendicular to the main shaft, and further comprising: In the process, each time the cylindrical material is fed in the horizontal direction orthogonal to the main axis by a unit length division value ΔX, the distance ΔZ of the main shaft is moved in the direction of its axis, and the distance around the axial center of the cylindrical material is The processing is performed while controlling the rotation angle ΔC according to the following relational expression: ΔZ=ΔXtanθ ΔC=(ΔX/LCOSθ)×360°.

[Effect]

When a cylindrical workpiece held in the work holding device of a machining center is tilted with respect to a rotating tool attached to the spindle, and the bed is moved in this state to move the cylindrical workpiece in a direction perpendicular to the spindle, the cylindrical workpiece will Moves parallel to the main axis while remaining tilted. Therefore, in order to move the rotary tool along the axis of the cylindrical material, it is necessary to move the rotary tool, that is, the main shaft, in the direction of the axis during processing.

To explain this using Fig. 3, if the rotary tool is initially in contact with the cylindrical material at a point A on the axis, then the cylindrical material has a division value of unit length in the X-axis direction. When it reaches point A' after being sent by ΔX, the axis of the cylindrical material has been displaced by ΔZ=ΔXtanθ in the Z-axis direction. Therefore, by simultaneously moving the rotary tool by ΔZ in the Z-axis direction while feeding the cylindrical material by ΔX, the rotary tool can be brought into contact with the cylindrical material at point B on its axis.

Therefore, each time the cylindrical material is fed by a unit length division value ΔX, the main axis is changed to ΔZ calculated according to the above relational expression.
If the rotary tool is moved by a distance of , the rotary tool will always move along the axis of the cylindrical material during machining, even if the torsion angle θ changes.

Also, by moving ΔZ, the rotary tool is sent in the axial direction of the cylindrical material by a distance of ΔS = ΔX/cosθ, so while being fed by this ΔS, the cylindrical material is moved at an angle ΔC = (ΔS/L) × By rotating around the axis by 360° = (ΔX/L cos θ) × 360°, a helical groove with a twist angle θ and a lead L can be formed.

〔Example〕

Embodiments of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a schematic diagram of main parts of a horizontal machining center used to implement the method of the present invention. 1 is a column of the machining sensor body, 2 is a bed provided in front of column 1 so that it can move in the left-right direction (X-axis direction), and 3 is a bed that can be rotated around a vertical axis (B direction) on the top surface of bed 2. Table set up at 4
is a workpiece holding device fixedly installed on the table 3.

A main shaft 5 is provided on the front surface of the column 1 and projects horizontally forward, and a processing tool such as a grindstone 6 is attached to the head of the main shaft 5 and rotated by a motor 7. The head of the main shaft 5 is movable in the front-rear direction (Z-axis direction), and the entire main shaft 5 is movable in the vertical direction (Y-axis direction) while maintaining a horizontal state.

The workpiece holding device 4 is configured to hold a workpiece by a pair of mutually opposing tailstocks 8a and 8b. As shown in FIG.
It is pressed and clamped by 8b and held in the horizontal direction. One tailstock 8a is arranged around its axis (C
direction), and the tool material can be rotated around its axis during machining.

Next, a processing method for processing a helical groove in a cylindrical tool material using a machining center having such a configuration will be described.

First, as shown in FIG. 2, a cylindrical tool blank 9 is clamped by pressing both end surfaces thereof through a pair of tailstocks 8a and 8b, and set on the workpiece holding device 4. Then, the table 3 is rotated in the direction B to tilt the tool material 9 with respect to the main spindle 5, and the rear end surface 6a of the grindstone 6 attached to the head of the main spindle 5 is
and the axis of the tool material 9 to match the helix angle (θ) of the groove. The table 3 is fixed on the bed 2 in this state during processing.

Next, the main shaft 5 is moved in the Y-axis direction and set to a height such that the cutting depth of the grindstone 6 into the tool material 9 becomes a predetermined groove depth. The main shaft 5 is fixed at this height during processing.

Furthermore, the bed 2 is moved in the X-axis direction, and the grinding wheel 6 is
is set so that it is located at the starting point of the helical groove to be formed in the tool material 9. From this state, grinding is performed using the rotating grindstone 6 while simultaneously controlling the feeding of the bed 2 in the X-axis direction, the movement of the main shaft 5 in the Z-axis direction, and the rotation of the tool material 9 in the C direction. For example, a helical groove is formed in the tool blank 9.

The movements of the bed 2, spindle 5, and tool blank 9 at this time are controlled according to the following equation.

ΔZ=ΔXtanθ ΔC=(ΔX／Lcosθ)×360° Here, ΔX is the X of the bed 2 and therefore the tool material 9.
The division value of the unit length of the feed amount in the axial direction, ΔZ is the moving distance of the spindle 5 in the Z-axis direction, ΔC is the tool material 9
, θ is the twist angle of the helical groove, and L is the lead of the helical groove. Control of each axis according to this relational expression can be easily realized by inputting a predetermined program into the NC control device of a normal machining center.

Next, the motions performed by the bed 2, spindle 5, and tool blank 9 in accordance with the above relational expression will be described in detail.

As shown in FIG. 3, first the rear end surface 6 of the grinding wheel 6
The lowest point of a is point A on the axis of the tip of tool material 9
Suppose that there is contact at . From this position, the tool material 9 moves in the X-axis direction by ΔX due to the movement of the bed 2.
When the point A is moved by a distance of , the point A moves to the position A' and the axis is displaced by ΔZ in the Z-axis direction.
At this time, similarly to point A, point B where the lowest end of the rear end surface 6a of the grinding wheel 6 is on the axis of the tool material 9.
In order to make contact with the tool material 9 at , the grindstone 6 must be moved by the distance ΔZ between AB in the Z-axis direction simultaneously with the feed of ΔX. It is clear that ΔZ can be calculated using the following formula.

ΔZ=ΔXtanθ Therefore, if the grindstone 6 is moved according to this formula, the lowest end of the grindstone 6 can always be moved along the axis of the tool blank 9.

Furthermore, when the grinding wheel 6 moves by ΔZ with the feed of ΔX, the grinding wheel 6 moves along the axis of the tool material 9.
This means that the distance ΔS between A′B was sent. Therefore, in order to form a helical groove with a helix angle θ and a lead L, the tool blank 9 must be moved in the C direction (direction around the axis) by an angle ΔC determined by the following formula during movement of this distance ΔS. must be rotated.

ΔC=(ΔS/L)×360° Here, since ΔS=ΔX/cosθ, ΔC=(ΔX／Lcosθ)×360° becomes.

Therefore, ΔZ=ΔXtanθ, ΔC=(ΔX／Lcosθ)×
If the values of X, Z, and C are determined so as to satisfy the 360° relational expression, a helical groove can be machined in the cylindrical tool material 9 using the horizontal machining center having the above structure.

In addition, if θ is set to a constant value in the above equation, a groove with an equal helical lead will be machined, but in this case, the following equations are generalized from the above two equations: Z=Xtanθ C=(X/Lcosθ)× All you have to do is control it so that it moves 360°.

In addition, when machining an unequal helical groove by gradually changing θ, the lead L also changes, so
It is necessary to calculate ΔZ and ΔC for each division value ΔX.

〔Effect of the invention〕

As is clear from the above description, according to the method of the present invention, a helical groove can be formed in the cylindrical material 9 using a horizontal machining center, and this method can be easily performed using the NC control device of a normal machining center. It can be realized and
It is economical because it does not require the use of an expensive tool grinder, and has excellent cost advantages.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of the main parts of a horizontal machining center used in the method of the present invention. FIG. 2 is an explanatory plan view showing the machining status of the tool material by the same machining center. FIG. 3 is an explanatory plan view showing the positional relationship when the tool material is displaced by ΔX in the X-axis direction. 1...Column, 2...Bed, 3...Table, 4...Work holding device, 5...Spindle, 6...
Grinding wheel, 6a... Rear end surface of grinding wheel, 7... Motor, 8
a, 8b...Tailstock, 9...Tool material, ΔX...
...The unit length division value of the feed amount in the X-axis direction, ΔZ...
…The moving distance in the Z-axis direction when moved by ΔX,
ΔC……Rotation angle in the C direction when sent by ΔX,
L...Lead of the helical groove, θ...Twist angle of the helical groove.

Claims (1)

[Scope of Claims] 1. A main shaft provided horizontally and movable vertically and in the direction of its axis, to which a rotating tool such as a grinding wheel is attached, and a workpiece that moves in a direction perpendicular to the main shaft. A machining center equipped with a bed on which a workpiece is placed, and a workpiece holding device provided on the bed and capable of rotating around a vertical axis in a horizontal plane and rotating a held workpiece material around its axis. A processing method for forming a helical groove of a helical angle θ and a lead L in a cylindrical material using so that a helical groove is formed.
a step of tilting the cylindrical material in a horizontal plane with respect to a rotary tool attached to the main shaft; a step of adjusting the positional relationship of the cylindrical material; and a step of processing the cylindrical material with the rotary tool while moving it in a horizontal direction perpendicular to the main axis; Every time the shaped material is fed by a unit length division value ΔX in the horizontal direction perpendicular to the main axis, the movement distance ΔZ of the main shaft in the direction of its axis and the rotation angle ΔC of the cylindrical material around its axis are calculated. A helical groove machining method using a machining center characterized by machining while controlling according to the following relational expressions: , ΔZ=ΔXtanθ ΔC=(ΔX/LCOSθ)×360°.