JP2000202719A - Elecrolytic grinding device for worm wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the efficiency of manufacturing a worm wheel by a grinding tool. SOLUTION: A first driving unit 10 for rotating/driving a worm-shaped grinding tool T and a second driving unit 20 for rotating/driving a work W are mounted on a common base frame 30. The first and second driving units 10, 20 can relatively move in the direction of a common perpendicular C3, with respective shaft centerlines C1, C2 intersecting at a right angle with each other. By impressing electric voltage between the grinding tool T and the work W, the work W can be electrolytically ground, creating and finishing worm wheel gears on the work W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic grinding apparatus for a worm wheel, which can improve the machining efficiency as a whole when grinding and creating teeth of the worm wheel.

[0002]

2. Description of the Related Art When forming a worm wheel, especially a drum-shaped worm wheel, a worm-shaped grinding tool having abrasive grains adhered to a screw surface is sometimes used (for example, Japanese Patent Application Laid-Open No. 8-206919). .

That is, a grinding tool having the same shape as a worm and a work serving as a worm wheel are set in a processing apparatus, and the grinding tool is rotated while rotating the grinding tool and the work so that a predetermined reduction ratio is obtained. It can be fed toward the heart to create the worm wheel teeth on the outer periphery of the workpiece. Note that the teeth of the worm wheel thus created can be finished to a predetermined accuracy by finish grinding through a grinding tool having a finer particle size.

[0004]

According to the prior art, a grinding tool must use two kinds of particles having different particle diameters depending on a worm wheel tooth forming process and a finishing process. When shifting from the creation process to the finishing process, it is necessary to replace the grinding tool, and there has been a problem that the overall machining efficiency is low.

Accordingly, an object of the present invention is to solve the problem of the prior art and eliminate the need to replace the grinding tool by applying a voltage between the grinding tool and the work via the first and second drive units. Accordingly, an object of the present invention is to provide an electrolytic grinding apparatus for a worm wheel, which can improve processing efficiency.

[0006]

In order to achieve the above object, the present invention provides a first drive unit for supporting and rotating a worm-shaped grinding tool and a second drive unit for supporting and rotating a workpiece. The first and second drive units are mounted on a common base frame such that their axes are orthogonal to each other and are relatively movable in a common perpendicular direction. The point is to apply a voltage in between.

The first drive unit can mount a grinding tool via a chuck on a drive shaft insulated from the base frame.

[0008] The first drive unit may be combined with an insulating center for steadying the grinding tool.

Further, the second drive unit can mount the work on the drive shaft via an insulating collar,
A center for steadying the work can be combined.

The first and second drive units may each be provided with a power supply brush.

[0011]

According to the structure of the present invention, the first and second drive units respectively operate the grinding tool and the grinding tool so as to obtain a predetermined reduction ratio based on the tooth lead of the grinding tool and the diameter of the work.
By rotating the work and approaching it in the common perpendicular direction, applying a voltage between the grinding tool and the work and applying electricity to the electrolyte between them, electrolytic grinding the outer peripheral surface of the work and creating worm wheel teeth It can be finished correctly. In addition, the grinding tool at this time removes a product from the work by the electrolytic grinding and mechanically grinds the work. Therefore, it is preferable to set the abrasive particles adhering to the surface of the grinding tool to a particle size equivalent to finish grinding. Here, the common perpendicular direction refers to a common perpendicular direction to each axis of the first and second drive units. In addition, the first and second
When the drive units are moved relative to each other in a common perpendicular direction to position both axes on the same plane, it is assumed that the axes are orthogonal to each other.

The first drive unit can supply a voltage for electrolytic grinding to the grinding tool via the drive shaft by providing the drive shaft insulated from the base frame;
The grinding tool can be easily attached to and detached from the drive shaft via the chuck.

When the insulating center is combined with the first drive unit, the center can prevent the grinding tool from oscillating and improve the grinding accuracy of the worm wheel formed on the workpiece.

The second drive unit can easily insulate the work from the drive shaft by mounting the work on the drive shaft via an insulating collar.

Further, the center for steadying the work further improves the grinding accuracy of the work.

If the power supply brush is provided in the first and second drive units, each brush supplies a predetermined voltage to the first and second drive units, respectively, and a predetermined voltage is applied between the grinding tool and the work. A voltage for electrolytic grinding can be applied.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

The electrolytic grinding apparatus for a worm wheel includes a first drive unit 10 for supporting a worm-type grinding tool T and a second drive unit 20 for supporting a workpiece W on a common base frame 30. It is mounted (Figs. 1 and 2).

The base frame 30 is formed by erecting a column 32 at one end of a bed 31. Bed 31
A moving frame 33 is mounted on the upper side so as to be able to move laterally so as to face the column 32.
, The second drive unit 20 is mounted on a horizontal portion,
An auxiliary frame 34 is mounted on the vertical portion so as to be able to move up and down. Further, the first drive unit 10,
An auxiliary frame 35 is attached. The base frame 30 is provided with an injection nozzle 39 in the vicinity of the first drive unit 10, and the injection nozzle 39 is connected to a not-shown electrolyte supply source.

The first drive unit 10 is installed in a horizontal state in which the axis C1 is parallel to the bed 31 and the column 32. The second drive unit 20 is such that the axis C2 is
It is installed vertically. Therefore, the first and second drive units 10 and 20 are arranged such that their respective axes C1 and C2 are orthogonal to each other. In addition, the first and second drive units 10 and 20 move the moving frame 33 laterally, thereby forming a common perpendicular C3 of the axes C1 and C2.
Relative movement in the direction.

The grinding tool T has thread-shaped teeth Ta having a predetermined pressure angle and a lead angle formed in a drum shape (FIGS. 2 and 3).
Abrasive grains such as diamond having a predetermined grain size are attached to the surface of the teeth Ta. Grinding tool T is key T2, lock nut T
It is assembled integrally with the shaft T1 with the stopper T3 via the pins 4 and T4.

The first drive unit 10 includes a drive shaft 11,
The chuck 12 and the connecting member 13 are formed by incorporating them into a bearing 15 (FIGS. 1 and 3). A cylindrical connecting member 1 is connected to the bearing 15 via angular contact type bearings 15e, 15e... And roller type bearings 15f, 15f.
3 is rotatably incorporated. Front bearing 1
Are held via an insulating cap 15b, and rear bearings 15f, 15f are provided with a holder 15c, a cap 15d with a packing 15d1,
It is held via a nut 13c mounted on the connecting member 13. The bearings 15e and 15f are, for example, ceramic bearings, and the inner cylinder and the outer cylinder are electrically insulated.

The bearing 15 is connected to the column 32 of the base frame 30 via an insulating sheet 15g and a bolt 15h,
15h... Each bolt 15
h is fastened via the insulating collar 15k.

The connecting member 13 contains a drive shaft 11 and a chuck 12 therein. However, the chuck 12 is a collet chuck, and the drive shaft 11 is connected via the connecting portion 11a.
Is connected to the front end. Further, a protection cap 13 d for the chuck 12 is attached to the front end of the connecting member 13. The drive shaft 11 is connected to a connecting member 13 via a key 11b.
A pulley 11e is mounted via a key 11c and a nut 11d at a rear portion of the drive shaft 11 protruding from the connecting member 13. The pulley 11e is
It is connected to a motor (not shown) via an insulating timing belt 11g. The boss 11 of the pulley 11e
A brush 16 for power supply is in contact with the outer periphery of f, and the brush 16 is attached to the bearing 15 via an insulating support member 16a.

The first drive unit 10 is combined with an insulating center 17. The center 17 is attached to the tip of the push shaft 17a incorporated in the auxiliary frame 35, and is installed on the axis C1 of the first drive unit 10.

Therefore, the first drive unit 10 is electrically insulated from the base frame 30 through insulating bearings 15e, 15e..., 15f, 15f and an insulating sheet 15g, and ground through the chuck 12. The tool T can be detachably supported. Further, the first drive unit 10 can rotate the grinding tool T around the axis C1 by rotating the drive shaft 11 via the belt 11g, and the center 17 swings the grinding tool T. Stop it. Further, the first drive unit 10 can supply a voltage to the grinding tool T via the brush 16.

The second drive unit 20 includes a spacer 22
h, mounted on the pedestal 33a of the moving frame 33 via the gantry 22 (FIGS. 1 and 4),
The main member is a drive shaft 21 that is supported via 2a, 22a, 22b, and 22b. Upper bearing 22a,
22a is held via a cap 22f with a sealing material 22g, and the lower bearings 22b, 22b
Are held via holders 22c1, 22c2 and a sealing material 22d. Note that the holder 22c1 is
2c2 is positioned via a cylindrical spacer 22e.

The drive shaft 21 has a pulley 21a mounted on a lower end protruding into the moving frame 33, and is connected to a motor (not shown) via a timing belt 21b wound around the pulley 21a. The work W can be mounted on the upper part of the drive shaft 21 via an insulating collar 23.
The work W is fixed via a conductive spacer 24, an insulating pressing member 25, and a nut 25a. A brush 26 for power supply is in contact with the outer peripheral surface of the spacer 24, and the brush 26 is attached to the auxiliary frame 34 via an insulating support member 26a.

The second drive unit 20 has a center 27
Are combined. The center 27 includes the auxiliary frame 3
4 through a push shaft 27a mounted on the second drive unit 2
It is installed downward on the zero axis C2. Push shaft 27a
Is vertically movably incorporated in a guide hole 34a of the auxiliary frame 34, and is urged downward via a compression spring 27b. The push shaft 27a is prevented from coming off via a stopper (not shown), and the upper end of the guide hole 34a is closed via a lid 34b having a protrusion 34c.

Therefore, the second drive unit 20 can attach and detach the work W via the nut 25a, and can supply a voltage to the work W via the brush 26. The second drive unit 20 can rotate the work W around the axis C2 by rotating the drive shaft 21 via the belt 21b.
Moves the work W by lowering the auxiliary frame 34 and engaging it with the upper end of the drive shaft 21.

The worm wheel electrolytic grinding apparatus operates as follows.

A grinding tool T and a work W are mounted on the first and second drive units 10 and 20, respectively, and the common perpendicular C3 of the first and second drive units 10 and 20 is
(FIG. 2). Subsequently, the grinding tool T is rotated via the first drive unit 10 (in the direction of the arrow K1 in the figure) so that a predetermined reduction ratio is obtained based on the diameter of the work W and the lead of the teeth Ta of the grinding tool T. , The workpiece W is rotated via the second drive unit 20 (in the direction of arrow K2 in FIG. 3), and an electrolytic solution such as a phosphoric acid solution is injected from the injection nozzle 39. , A voltage for electrolytic grinding is applied between the work W and the work W
In the direction of the common perpendicular C3 (in the direction of arrow K3 in the figure). However, when the material of the work W is a copper alloy, the brushes 16 and 26 apply a voltage so that the grinding tool T side becomes a negative electrode and the work W side becomes a positive electrode.

Therefore, the grinding tool T can electrolytically grind the work W at the contact portion with the work W, and create teeth of the worm wheel on the outer peripheral surface of the work W following the teeth Ta. The grinding tool T at this time discharges a product generated by the electrolytic grinding to the outside and mechanically grinds the work W.

When the teeth of the work W are created to the predetermined tooth height, the feeding of the work W by the moving frame 33 is stopped. Then, the grinding tool T can finish all teeth of the work W sufficiently to a predetermined pressure angle and a predetermined lead angle by rotating the work W, thereby completing the worm wheel.

In the above description, the feeding speed of the workpiece W in the generating process depends on the particle diameter of the abrasive grains of the grinding tool T, the voltage between the grinding tool T and the workpiece W, the current density, the electrolytic capacity of the electrolytic solution, and the like. It can be adjusted and set arbitrarily. In the finishing step of the work W, the application of the voltage for electrolytic grinding by the brushes 16 and 26 may be stopped, and only the mechanical grinding by the grinding tool T may be performed.

On the other hand, the grinding tool T is not limited to a drum-shaped worm, but may be a general worm. By moving the first drive unit 10 instead of the second drive unit 20, the grinding tool T may be sent to the work W in the direction of the common perpendicular C3. The bearing 15 is
Insulating bearings 15e, 15e ..., 15f, 15f
When using, the insulating sheet 15g may be omitted,
Conversely, when using the insulating sheet 15g, it is not always necessary to use the insulating bearings 15e, 15e..., 15f, 15f. The grinding tool T may be mounted on the shaft T1 via an insulating collar like the work W.
At this time, the drive shaft 11 need not be insulated from the base frame 30.

[0037]

As described above, according to the present invention, the first drive unit for rotating and driving the grinding tool and the second drive unit for rotating and driving the work are combined to form the first and second units. The drive unit makes the respective axes perpendicular to each other and makes it relatively movable in the common perpendicular direction.
By applying voltage between the workpieces, the workpieces can be electrolytically ground and the worm wheel teeth can be easily created and finished at once, eliminating the need for grinding tool replacement work and improving overall machining efficiency. There is an excellent effect that it can be greatly improved.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an overall configuration side view.

FIG. 2 is a schematic explanatory view of a main part.

FIG. 3 is an enlarged sectional explanatory view of a main part of FIG. 1 (1);

FIG. 4 is an enlarged sectional explanatory view of a main part of FIG. 1 (2).

[Explanation of symbols]

 T: grinding tool W: work C1, C2: axis C3: common perpendicular line 10: first drive unit 20: second drive unit 30: base frame 11, 21, drive shaft 12: chuck 16, 26: brush 17 , 27 ... Center 23 ... Color

Claims (6)

[Claims] A first drive unit that supports and rotates a worm-shaped grinding tool; and a second drive unit that supports and rotates a work.
The second drive unit, for a common base frame,
An electrolytic grinding apparatus for a worm wheel, characterized in that the axes are orthogonally mounted so as to be relatively movable in a common perpendicular direction, and a voltage is applied between a grinding tool and a workpiece. 2. The electrolytic grinding for a worm wheel according to claim 1, wherein the first drive unit mounts a grinding tool via a chuck on a drive shaft insulated from the base frame. apparatus. 3. The electrolytic grinding apparatus for a worm wheel according to claim 2, wherein said first drive unit is combined with an insulating center for preventing a vibration of a grinding tool. 4. The electrolytic grinding for a worm wheel according to claim 1, wherein the second drive unit mounts the work on a drive shaft via an insulating collar. apparatus. 5. The electrolytic grinding apparatus for a worm wheel according to claim 4, wherein said second drive unit is combined with a center for preventing a work from oscillating. 6. The electrolytic grinding apparatus for a worm wheel according to claim 1, wherein each of the first and second drive units is provided with a power supply brush.