JP3149906B2 - Shaft hole finishing method for wheels for railway vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to finishing how of the shaft hole to press the wheel for a railway vehicle in the car axis.

[0002]

2. Description of the Related Art Wheels for railway vehicles (hereinafter referred to as wheels) are:
After processing the rim portion and the shaft hole of the rolled wheel, the inner surface finishing of the shaft hole is performed, and the wheel is pressed into an axle that has been subjected to the outer surface finishing to be assembled as a wheel shaft. Conventionally,
For the inner surface finishing of the shaft hole of the wheel, a special machine called a boring machine with a numerical control device is used, and the inner surface finishing of the shaft hole is performed using a finishing bite, a hale finishing bite, a polishing roller or a combination of these as a cutting tool. Generally, it is performed by automatic control.

[0003] The pressure input when the wheel is pressed into the axle is
If it is too low, the interference will be insufficient and slippage will occur between the wheel and the axle, resulting in axle slippage. On the other hand, if the press-fit is too high, a galling failure occurs at the time of press-fit, and the wheels and axles may be damaged. For this reason,
In the finishing of the inner surface of the shaft hole of the wheel, the dimensional tolerance of 0.02 required to secure the interference when the wheel is pressed into the axle.
mm.

[0004]

In the finishing of the inner surface of a shaft hole by automatic control using a special machine called a boring machine with a numerical control device, when a grinding roller is used, when the wheel is pressed into the axle, A phenomenon called "discontinuously called" is seen. When using a finishing bit or a heel finishing bit, the dimensional tolerance of about 0.02 mm required to secure the interference when pressing the wheel into the axle is required. Because it cannot be satisfied, press-in force is insufficient as described later,
There was a problem that there was a large variation in press-fitting. For this reason, the finishing of the inner surface of the shaft hole of the wheel must rely on a manual operation by a skilled worker.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art, and to use a vertical lathe with a numerical control device conventionally used for wheel machining to achieve a dimensional tolerance of 0. An object of the present invention is to provide a method and an apparatus for finishing a shaft hole of a wheel for a railway vehicle, which can satisfy about 02 mm, can secure a press-fit when the wheel is press-fitted into an axle, and can reduce variation in the press-fit.

[0006]

SUMMARY OF THE INVENTION The present invention, when manufacturing the wheel slave come railcar to the main shaft of the automatic tool change type numerical control apparatus with vertical lathe used for general machining, several prismatic A rod-shaped fine grain grinding wheel is equipped with a honing head that can apply contact pressure to the inner surface of the shaft hole by hydraulic pressure, and the peripheral speed and vertical movement speed of the honing head are controlled to make the intersection angle of the grinding pattern (axial direction) 65 ° It is to be finished at ~ 95 °. As described above, when manufacturing wheels for railway vehicles in the past, several square rod-shaped fine-grained grinding wheels were provided on the main shaft of a vertical lathe with an automatic tool changing type numerical control device, which has been used for general machining, by hydraulic pressure. Equipped with a honing head that can apply contact pressure to the inner surface, and control the peripheral speed and vertical movement speed of the honing head to intersect angle of grinding pattern (axial direction)
By finishing at 65 ° to 95 °, the amount of grinding in one reciprocation of the honing process is only 1μm, so the shaft hole diameter can be adjusted with high precision and the dimensional tolerance of 0.02mm required to secure the interference The degree of satisfaction can be satisfied , the pressure input when the wheel is pressed into the axle can be secured, and the variation of the pressure input can be reduced. In addition, the honing tool is automatically mounted instead of the cutting tool on the spindle of the automatic tool change type numerically controlled vertical lathe, which has been used for general processing of railway vehicle wheels, without moving the wheels during processing. Finishing of the inner surface of the shaft hole can be performed, and automation and labor saving can be achieved.

[0007] The automatic tool changer type numerical control vertical honing head mounted on the lathe spindle, alumina abrasive grains WA54
A K-class whetstone is widened by a hydraulic cylinder and pressed against the inner surface of the shaft hole of the wheel with a pressing force of 12 to 13 kgf / cm ² ,
The crossing angle of the grinding pattern (axial direction) is 65 ° by the control means.
By numerically controlling the peripheral speed of the fine-grain grindstone and the vertical feed speed of the fine-grain grindstone by the rotation of the spindle of the vertical lathe so as to be up to 95 °, the grinding amount in one reciprocation of the honing process is only 1 μm. Therefore, the shaft hole diameter can be adjusted with high accuracy,
It is possible to satisfy the dimensional tolerance of about 0.02 mm required for securing the interference, to secure the press-in force when the wheel is pressed into the axle, and to reduce the variation in the press-in force. In addition, the use of an automatic tool changeable numerically controlled vertical lathe, which has been conventionally used for general processing of railcar wheels, allows the wheels to move only by automatically mounting a honing tool instead of a cutting tool on the spindle. Finishing of the inner surface of the shaft hole can be performed without any need, and automation and labor saving can be achieved.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION A shaft hole of a wheel for a railway vehicle according to the present invention.
In the finishing process , the crossing angle (axial direction) of the grinding pattern by the honing head was set to 65 ° to 95 ° .If it was less than 65 °, the press-in force might be too high, and galling failure occurred during press-in, Wheels and axles may be damaged, and if the angle exceeds 95 °, the press-in force is too low and the interference is insufficient, slipping may occur between the wheels and the axle, and the axle may slip. Because there is.

The honing tool used in the present invention is detachable from the spindle of an automatic tool changing type numerically controlled vertical lathe by an automatic tool changing device. Also, when the honing tool is inserted into a shaft hole of a wheel, the grinding wheel is shrunk and inserted. After widening 12-13kgf
It has a function of expanding the hydraulic pressure for securing a pressing force of about / cm ^2, and has an automatic connection mechanism for hydraulic ports for that purpose. The vertical stroke of the honing tool is set by the following formula so that the amount of protrusion of the wheel of the grinding wheel 61 from the boss portion 62 becomes approximately 1/3 of the grinding wheel length S1 as shown in FIG. S = L + Ou + Ol-Sl where S: stroke length (mm), L: machining length (mm) (wheel boss width), O
u: Projection amount at upper end (mm), Ol: Projection amount at lower end (mm), Sl: Grinding stone length (mm)

In order to make the crossing angle (in the axial direction) of the grinding pattern by the honing head 65 ° to 95 °, the vertical feed speed of the honing tool mounted on the main shaft of the numerically controlled vertical lathe via a shank, and the honing speed It is necessary to control the peripheral speed of the fine-grain grindstone of the head. For example, when the intersection angle is 90 °, it is necessary to control the vertical speed and the peripheral speed to be the same. The vertical feed speed and the fine-grain grindstone peripheral speed are arithmetically controlled by the control unit in accordance with the set intersection angle of the grinding pattern (axial direction).

The grinding wheel of the honing head, like the wheel outer diameter grinding process, depends on the material to be machined, hardness, cutting oil, cutting conditions, required surface roughness, etc., and the type, hardness, size, Determining the degree of bonding and the like, processing of the wheel axle hole using a water-soluble cutting oil agent uses a grinding stone of the alumina abrasive grain WA54K class as a guide for selection.

Usually, water-soluble cutting oil is used in high-speed cutting of steel by a numerically controlled vertical lathe, but in honing processing, non-water-soluble cutting oil is generally used. Since the clogging of the whetstone is easy to occur, use an emulsion or soluble type water-soluble cutting oil and select the whetstone particle size and the degree of bonding that do not cause clogging.

The amount of grinding in one round of honing is
As shown in FIG. 6, the diameter is only 1 μm, and the shaft hole diameter can be adjusted with high accuracy. Therefore, the securing of the target size of the shaft hole diameter by the honing process is set based on FIG. 6. However, if the variation in the shaft hole diameter can be suppressed by the pre-honing process, the honing process can be automated.

[0014]

【Example】

Embodiment 1 A shaft hole finishing method according to the present invention will be described below with reference to FIGS. FIG. 1 shows a mounting shank and a honing head of a shaft hole finishing machine according to the present invention.
(A) is a side view, (b) is a bottom view, and FIG. 2 is an explanatory view of enlargement / reduction of a grinding wheel of a honing head. The left half is a sectional view when the grinding wheel is reduced, and the right half is a sectional view when the grinding wheel is expanded. .

In FIG. 1 and FIG. 2, reference numeral 1 designates an extension cylinder 4 to which a hydraulic pipe 3 is connected with a connection portion 2 fitted to a mounting shaft shank of a main shaft (not shown) which can be raised and lowered while rotating, which is not shown. The outer cylinder 6 surrounding the outer periphery of the piston rod 5 of the expansion cylinder 4 of the mounting section shaft 1 is provided with two pins 7 in the 180 ° direction. Reference numeral 8 denotes a float joint having a two-stage sliding arm 11 having an L-shaped groove portion 9 for fitting with the pin 7 at the upper portion, and a dovetail groove for fitting the pin 10 at an interval of 60 ° in the lower reduced diameter portion. In the inside of the float joint 8, a connecting rod 13 having a dovetail to which a pin 12 connected to the piston rod 5 of the expansion cylinder 4 is fitted is internally fitted, and the expansion cylinder 4 is operated to extend the piston rod 5. Then, the connecting rod 13 is lowered along the pin 12 as shown on the right side of FIG.

Reference numeral 14 denotes a fixing member for a rectangular bar-shaped fine grain grinding wheel 15 connected to the tip of each sliding arm 11, and reference numeral 16 denotes a fan-like supporting member fitted in two stages between the fixing members 14 below the float joint 8. Thus, the vibration of the fixing member 14 of the fine-grain grindstone 15 at the time of honing the shaft hole 18 of the wheel 17 is configured to be prevented. Reference numeral 19 denotes a contraction spring of each sliding arm 11 which operates the expansion cylinder 4 to contract the piston rod 5 and moves the connecting rod 13 along the pin 12.
2 is raised as shown on the left side of FIG. 2, the width of each sliding arm 11 is reduced, and the width of the fine grain grindstone 15 is reduced.

When the shaft hole 18 of the wheel 17 is to be honed by the above-described structure, a mounting shaft fitted to a mounting shaft shank of a main shaft (not shown) that can be rotated and raised and lowered, which is not shown, of the shaft hole finishing device. The L-shaped groove 9 of the float joint 8 of the honing head, which matches the shaft hole 18 of the wheel 17, is fitted to the pin 7 of the outer cylinder 6, and the wheel 17 is mounted on a table of a shaft hole finishing machine (not shown). Are fixed so that the shaft hole 18 is coaxial with the main shaft. Thereafter, with the sliding arm 11 contracted, the fine grain grindstone 15 is inserted into the shaft hole 18 such that the upper third of the fine grain grindstone 15 is located above the boss of the wheel 17.

Thereafter, the expansion cylinder 4 is operated via the hydraulic pipe 3 to extend the piston rod 5 to push out each sliding arm 11 by the cone portion of the connecting rod 13 to widen each fine-grain whetstone 15 to a predetermined size. Letting force 12
Press at １３13 kgf / cm ² . Then, while driving the shaft hole finishing device and rotating the main shaft at a predetermined speed, the lower third of the fine-grained grindstone 15 is bossed on the wheel 17 at a predetermined elevating speed while spraying the cutting oil. After being lowered to a lower position, the upper third of the fine-grain grindstone 15 is repeatedly raised at the same elevating speed until it is positioned above the boss portion of the wheel 17, and the honing of the shaft hole 18 of the wheel 17 is repeated. Processing was performed. In this case, the rotation speed and the elevating speed of the main shaft are automatically controlled so that the intersection angle of the grinding pattern (cross hatch) is 65 ° to 105 °.

In the above honing, the number of reciprocations of the honing is controlled based on the relationship between the number of reciprocations of the honing and the amount of change in the inner diameter of the shaft hole 18.
The finish processing of the shaft hole 18 was possible within the dimensional tolerance of 0.02 mm of the inner diameter of the shaft hole 18 of the wheel 17.

Example 2 An automatic tool changing type numerically controlled vertical lathe was used, a finishing tool, a hale finishing tool and a honing tool were used as grinding tools, a shaft hole diameter was 190 mm, and a specific gravity was 1.8 as a lubricant.
2. Using a water-soluble cutting oil emulsion, the inner surface roughness of the shaft hole
When each wheel finished to 2Ra was press-fitted into the axle similarly finished on the outer peripheral surface at a press-fitting speed of 150 mm / min to form a wheel axle, the press input at the press-fit into the axle and the standard deviation of the press input were obtained. The results are shown in Table 1 and FIG.

[0021]

[Table 1]

As shown in Table 1 and FIG. 3, the press-in force tends to increase in the order of the finishing bite, the hale finishing bite, and the honing tool, and as is clear from the standard deviation value, the variation of the press-in force is also in the above order. It tends to decrease.

Example 3 An automatic tool change type numerically controlled vertical lathe was used, a honing tool was used as a grinding tool, a shaft hole diameter was 190 mm, and a water-soluble cutting oil emulsion having a specific gravity of 1.8 was used as a lubricant.
In finishing the inner surface roughness of the shaft hole to 3.2 Ra, the vertical speed of the honing head and the peripheral speed of the fine-grain grindstone are controlled, the pressing force of the fine-grain grindstone is 12 to 13 kg / cm ² , and the intersection angle of the grinding pattern is 0 °. , 45 °, 90 °, 180 °, and each finished wheel is press-fitted into an axle whose outer peripheral surface is similarly finished at a press-fit speed of 150 mm / min to form a wheel axle. And the relationship between press-fitting and axle press-fitting were investigated. FIG. 4 shows the results.

As shown in FIG. 4, if the crossing angle of the grinding pattern in the honing process is set to 65 ° to 105 °, the required force input 65 to 105 to press the wheel into the axle.
n can be obtained, press-in galling due to excessive press-in can be prevented, and the interference is insufficient due to insufficient press-in, slippage between the wheel and the axle does not occur, and there is no danger of slippage of the axle.

[0025]

The shaft hole finishing method according to the present invention provides a honing capable of applying a contact pressure to an inner surface of a shaft hole by hydraulic pressure on several square rod-shaped fine-grained grinding wheels on a spindle of an automatic tool changing type numerically controlled vertical lathe. By installing the head and controlling the peripheral speed and vertical moving speed of the honing head to finish at the intersection angle (opposite axis direction) of the grinding pattern of 65 ° to 95 °, the finishing cost of the inner surface of the wheel shaft hole together with greatly reduced to about 1/2 of the conventional methods, can be processed finish the shaft hole inner surface below dimensional tolerances 0.02 mm, galling pressed by the press-fitting force excessive press-fitting the wheel on the axle and pressed shortages by interference Shortage can be prevented.

In the shaft hole finishing apparatus according to the present invention, the contact pressure to the inner surface of the shaft hole is hydraulically applied to the connecting rods of several square rod-shaped fine grain grinding wheels mounted on the main shaft of the automatic tool change type numerically controlled vertical lathe. A honing head that can be applied, a hydraulic cylinder connected to the honing head that widens the fine-grain grinding wheel, and a fine-tuning by rotating the spindle of the numerically controlled vertical lathe so that the intersection angle (opposite axis direction) of the grinding pattern is 65 ° to 95 °. Since it has control means for calculating and controlling the peripheral speed of the grain grinding wheel and the vertical feed speed of the fine grain grinding wheel, the finishing cost of the inner surface of the shaft hole of the wheel can be significantly reduced to about 1/2 of the conventional method, can be processed finish the shaft hole inner surface below dimensional tolerances 0.02 mm, wheels can be prevented insufficient interference by galling and pressed shortages pressed by the press-fitting force excessive press-fitting to the axle.

[Brief description of the drawings]

FIG. 1 shows a mounting shank and a honing head of a shaft hole finishing machine according to the present invention, wherein FIG.
(B) is a bottom view.

FIG. 2 is an explanatory view of enlargement / reduction of a grindstone of a honing head, wherein a left half is a sectional view when the grindstone is reduced, and a right half is a sectional view when the grindstone is expanded.

FIG. 3 is a graph showing a relationship between an inner surface finishing method and a press-fitting pressure when a wheel is press-fitted into an axle according to a second embodiment.

FIG. 4 is a graph showing a relationship between a crossing angle of a grinding pattern and a press-fitting pressure when a wheel is press-fitted into an axle in a third embodiment.

FIG. 5 is an explanatory diagram of a method of calculating a vertical stroke length of a grindstone.

FIG. 6 is a graph showing the relationship between the number of reciprocating honing operations and the amount of change in the bore diameter of the shaft hole.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Attachment part shaft 2 Connection part 3 Hydraulic piping 4 Expansion cylinder 5 Piston rod 6 Outer cylinder 7, 10, 12 pin 8 Float joint 9 Fitting L-shaped groove part 11 Sliding arm 13 Connecting rod 14 Fixed member 15 Fine-grain grindstone 16 Support member 17 Wheel 18 Shaft Hole 19 Reduced Width Spring 61 Whetstone 62 Boss

Continuation of the front page (56) References JP-A-8-216015 (JP, A) JP-A-5-16030 (JP, A) JP-A-56-119365 (JP, A) Jpn. , U) Japanese Utility Model Hei 4-42357 (JP, U) Japanese Utility Model Utility Model 40-33588 (JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) B24B 33/00-33/06 B24B 5/46

Claims (1)

(57) [Claims] 1. A method for finishing a shaft hole of a wheel for a railway vehicle, comprising a honing process in which a grindstone of an alumina abrasive grain WA54K class is pressed against an inner surface of the shaft hole with a pressing force of 12 to 13 kgf / cm ^2. A shaft hole finishing method for a wheel for a railway vehicle, wherein finishing is performed at a crossing angle (in the axial direction) of 65 ° to 95 ° of a grinding pattern.