JPH03131467A - Cutting method for rod-shaped workpiece - Google Patents

Abstract

PURPOSE:To prevent the generation of a burr around a cutout surface and the loss of flatness, and improve dimensional accuracy after cutting by supporting the axial part of a rod-shaped workpiece for the rotation thereof in a constant direction, and cutting the axial end part of the workpiece with a grinding wheel rotating about an axial line in parallel to the axis of the workpiece. CONSTITUTION:In cutting the axial end part 1a of an engine valve 1, the axial part 1b of the valve 1 is first placed on both rollers 2 and 6, and then a loader head 9 is adjusted, thereby so positioning the axial end part 1a as to protrude beyond the back of a diamond grinder 11 by the predetermined cutting tolerance. Also, the axial part 1b is pressed with a pressure roller 8. Thereafter, the engine valve 1 and the grinding wheel 10 are rotated and concurrently the whole of the wheel 10 is moved left together with a motor 10, thereby cutting the axial end part 1a with the peripheral edge part of the diamond grinder 11 rotating at a high sped.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cutting method for cutting the shaft end of a rod-shaped workpiece, such as an engine valve, using a grinding wheel.

[Conventional technology]

Poppet-type engine valves are usually formed into a valve original through a pressing process and a heat treatment process, and then the shaft end is cut to give a predetermined length.

Generally, a grinding wheel is used to cut the shaft end, and at this time, the engine valve is processed while being fixed.

[Problem to be solved by the invention]

If you fix the workpiece and cut it as described above,
This may cause cracks to appear around the cut surface, or the flatness (straightness) of the cut surface may be impaired.

If this happens, the dimensional accuracy of the entire length will vary, and this will have an adverse effect on the subsequent polishing process of the shaft portion and shaft end, or the welding process of the tip to improve wear resistance.

Furthermore, since uniform cooling by the cooling liquid is not performed, there is a risk that the surface to be cut will be burnt and thermal strain may occur.

The present invention was made to solve the above-mentioned problems when cutting rod-shaped workpieces such as engine valves, and it prevents the formation of burrs around the cut surface, increases the flatness of the cut surface, and It is an object of the present invention to provide a method for cutting a bar-shaped workpiece that can improve dimensional accuracy and quality by preventing burns from occurring on the cut surface.

[Means to solve the problem]

In order to achieve the above object, the method of the present invention supports the shaft of a rod-shaped work while rotating it in a fixed direction.

It is characterized in that the shaft end of the workpiece is cut by a grinding wheel that rotates around an axis that is parallel to the shaft.

[For production]

When the shaft end of a rod-shaped workpiece is cut by the method of the present invention, a highly accurate cut surface with high flatness and no burr can be obtained due to the synergistic effect of the rotation of the grinding wheel and the rotation of the workpiece.

Furthermore, since the cutting position of the workpiece constantly changes in the circumferential direction, the cooling effect of the cooling liquid is high, and burns are prevented from occurring on the cut surface.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

1 and 2 schematically show the main parts of a cutting machine used for carrying out the present invention.

A pair of drive rollers (2) (2) having the same diameter and spaced apart from each other and facing each other in the front and back are connected to each other by a drive # (3).

Both drive rollers (2) (2) are integrally rotated in a clockwise direction when viewed from the front by a driven gear (4) fixed to the front end of the drive shaft (3) meshing with the drive gear (5) and rotating. be rotated to

(6) is a driven roller of the same shape and size as the driving roller (2), which is located close to each driving roller (2) and lined up on the same plane as the driving roller (2), and the front and rear driven rollers (6) (6) are Driven shaft (7)
are connected to each other by.

Workpiece, i.e. the shaft part (1b) of the engine valve (1)
are both drive rollers (2) (2) and both drive rollers (6) (
a press roller (8) which is placed on the opposite surface of 6) and whose rotating shaft (8a) is slightly inclined with respect to the shaft part (1b) and which can be raised and lowered;
is being pressed from above.

When the drive gear (5) is rotated by a motor (not shown), the engine valve (1) is rotated by the suppression roller (8).
It is rotated counterclockwise as viewed from the front while being given a thrust forward (downward in FIG. 1) by.

At the center of the entire surface (1c) of the engine valve (1) is a loader head (9) that is rotatable and whose position can be adjusted longitudinally.
are in contact with each other, and the shaft end (la) can be positioned by protruding from both rollers (2) and (6) at the rear (upper side in FIG. 1) by an arbitrary length.

(10) is a grinding wheel whose left end faces parallel to the rear driven roller (6), and a ring-shaped diamond grinding wheel (11) with a thickness of approximately 1.5 m is used to extend the peripheral edge to the required length. It is made to protrude and is held between the front and rear press plates (12a) and (12b).

(13) connects the grinding wheel (10) to the engine valve (
1) with a drive motor for rotation relative to 1), that is, in a counterclockwise direction when viewed from the front.

It can be moved left and right on a bed (not shown).

To cut the shaft end (1a) of the engine valve (1), first place the shaft (lb) on both rollers (2) and (6), then adjust the loader head (9). , shaft end (1
a) by a predetermined cutting amount using a diamond grindstone (
11), and position it so that it protrudes rearward than 11), and press the shaft portion (1b) with the suppression roller (8).

Next, the engine valve (1) and the grinding wheel (10) are rotated, and at the same time, the grinding wheel (10) is rotated together with the motor (13).
When the entire lO) is moved to the left, the shaft end (la) becomes
Cutting is performed by the peripheral edge of a diamond grindstone (11) rotating at high speed.

At this time of disconnection, the engine valve (1) is
), the loader head (9) rotates while being pressed against the loader head (9) at all times.
Axial movement is prevented.

〔Effect of the invention〕

The cutting position is always constant, and variations in the dimensional accuracy of the overall length are prevented.

Because the workpiece is cut while rotating, unlike conventional methods,
This prevents the occurrence of cracks around the cut surface and loss of flatness, and improves the dimensional accuracy after cutting.

Furthermore, since the cutting position constantly changes in the circumferential direction, the cooling effect of the cooling liquid is high, and therefore there is no risk of burning the surface to be cut.

Furthermore, because it solves the problem of cracking and burning, instead of using ordinary grindstones that use abrasive grains such as emery, which wear out relatively quickly, diamonds, which have good cutting properties and have low wear, are used. It becomes possible to use a whetstone,
The number of pieces processed per grindstone increases, increasing productivity.

If the end of the workpiece opposite to the surface to be cut is cut while being pressed against a suitable rotating body, the workpiece will always be cut at a constant position, so the dimensional accuracy of the entire length of the workpiece after cutting will be more stable.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of the main parts of a cutting machine used to carry out the method of the present invention, and FIG. 2 is a longitudinal sectional front view taken along line A-A in FIG. 1. (1) Engine valve (work) (1a) Shaft end (2) Drive roller (4) Driven gear (6) Driven roller (8) Press roller (9) Loader head (11) Diamond grindstone (13) Motor (1b ) Shaft (3) Drive shaft (5) Drive gear (7) Driven shaft (8a) Rotating shaft (10) Grinding wheel (12a) (12b) Holding plate

Claims (2)

[Claims] (1) A rod-shaped workpiece characterized in that the shaft portion of the rod-shaped workpiece is supported and rotated in a fixed direction, and the shaft end portion of the workpiece is cut by a grinding wheel that rotates around an axis parallel to the shaft. cutting method. (2) The method for cutting a rod-shaped workpiece according to claim (1), characterized in that the rod-shaped workpiece is cut by a grinding wheel while pressing the shaft end portion of the rod-shaped workpiece opposite to the portion to be cut against a suitable rotating body. .