JP2582246B2 - Quenching and cooling method of rotating body - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a cooling method for one-shot hardening a comparatively wide peripheral surface of a shaft member, a cylindrical member or the like along an axial direction. The present invention relates to a quenching and cooling method for a rotating body applied regardless of a pulley, a V roller, or the like.

(Prior art) Relatively short shaft member, cylindrical member, etc. (hereinafter referred to as work)
As an example of a conventional method of one-shot hardening the peripheral surface of a work, a work W is placed on a rotary table T that can be displaced up and down as shown in FIG. The work W is displaced so that the work W is positioned within the winding of the heating coil C, and the work W is heated in a rotating state. When the peripheral surface of the work W rises to a predetermined quenching temperature, the rotary table T is displaced downward to position the work W in the ring of the annular cooling jacket J ', and a hole is formed in the inner peripheral surface of the cooling jacket J'. The cooling liquid ejected from the cooling fluid ejection hole is hit against the peripheral surface of the work W in a rotating state to be rapidly cooled.

In addition, in the case of a long shaft member or a cylindrical member, if the longitudinal quenching range is not long enough to move and quench, one-shot quenching is performed as shown in FIG. 3 (b). You. In this case, after the quenched peripheral surface H of the rotating work W supported by the center is positioned within the winding of the heating coil C and heated, it is positioned within the ring of the cooling jacket J 'having an annular shape by relative movement. Allow to cool.

(Problems existing in the prior art) In the one-shot quenching, no problem occurs when the quenching width along the longitudinal direction of the workpiece W is narrow, but as shown in FIGS. 3 (a) and 3 (b), quenching is performed. In the case of the work W having a certain width, uneven baking often occurs, and there is a risk that uniform hardening in the width direction may not be achieved.

By the way, it is said that the cause of baking unevenness, which is known from experience, is that a vapor film is locally formed on the surface of the work W, and the cooling of the part by the subsequent cooling fluid is hindered.

However, in spite of the fact that the cooling fluid is injected at an injection pressure enough to break the vapor film, and the work W is rotated to cool off the vapor film and the cooling is executed, there is actually occurrence of burning unevenness, In particular, when the peripheral surface is a non-parallel peripheral surface, there is a possibility that the peripheral surface frequently occurs, and therefore, a countermeasure has been desired.

(Object of the Invention) The present invention has been made in order to solve the problems in the conventional method of one-shot hardening the peripheral surface of a workpiece W having a relatively large quenching width. It is an object of the present invention to provide a method of quenching and cooling a rotating body that can be uniformly quenched.

(Procedure leading to the invention) In the process of completing the present invention, the inventor considered the behavior of the cooling fluid injected from the conventional annular cooling jacket J '.

In the case of FIG. 3 (a), after the cooling fluid collides with the peripheral surface of the work W, it escapes along the upper end surface on the upper side of the peripheral surface as shown by the arrow and immediately flows down from the edge on the lower side, as shown by the arrow. At the center, the downward flow tends to be hindered by the injection pressure of the cooling fluid that is subsequently injected on the lower side.

In the case of FIG. 3 (b), after the cooling fluid collides with the peripheral surface of the work W, the cooling fluid immediately flows down along the peripheral surface of the work W on the lower side as shown by the arrow, but the central part on the upper side of the peripheral surface. The injection pressure of the cooling fluid to be subsequently injected on the side is obstructed under the flow and rises above the cooling jacket J 'to prevent the outflow,
Also, there is a tendency for the flow to be hindered at the center by the injection pressure of the cooling fluid that is subsequently injected at the lower side.

Thus, when the cooling fluid is prevented from escaping or flowing out,
Judging that the vapor film formed on the surface of the work W is likely to be preserved by the staying cooling fluid and cause uneven burning, the cooling fluid after the impact on the peripheral surface of the work W is quickly and uniformly distributed in the radial direction. It was inferred that if the escape was possible, it would be possible to eliminate the occurrence of uneven grilling, and the present invention was completed.

(Constitution of the Invention) The constitution of the present invention is as follows: (1) In the case of quenching subsequent to heating when one-shot quenching is performed relatively widely along the axial direction on the peripheral surface of a rotating body which is a member that rotates, (2) Rotation of the shaft A plurality of coolers each having a cylinder having an axis parallel to the axis of the above-mentioned member are arranged on a circumference which is separated from the peripheral surface of the above-mentioned member by a predetermined distance, such that a predetermined distance is maintained between adjacent members. (3) The peripheral area of the cooling fluid ejected from the cooling fluid injection hole formed in the wall facing each member of the cooler is maintained at a predetermined distance from the adjacent impact area. (4) By impinging the cooling fluid from the cooling fluid injection hole on the peripheral surface of the member while rotating the member, the cooling fluid after impinging on the peripheral surface of the member is cooled by the member. Gap between adjacent coolers sent to the rear of rotation along the circumference In quenching method of cooling rotating body, characterized in that set to al escape.

(Effect of the Invention) The present invention has an effect of immediately and evenly radiating the cooling fluid after hitting the peripheral surface of the member rotating with the shaft in the radial direction without being disturbed by the subsequent cooling fluid.

(Embodiment) The present invention will be described in detail with reference to an embodiment shown in FIGS. 1 (a) and 1 (b).

In the figure, W is a work composed of a rotating body that is a member that rotates about the axis, C is a heating coil, T is a rotary table, and J1 to
8J are coolers arranged below the heating coil C. The cooler is arranged at an angle of 45 ° on a circumference that is separated from the peripheral surface of the work W placed on the rotary table T by a predetermined distance when the rotary table T is in the downward displacement position. In the example, it has a cylindrical shape, has a predetermined diameter such that a predetermined interval is maintained between adjacent coolers, has a length corresponding to a quenching width, and has an axis line corresponding to the workpiece W.
Is parallel to the axis. In each of the coolers 1 to 8,
A plurality of cooling fluid injection holes indicated as s are provided on the peripheral surface side of the work W. Thus, the impingement range of the cooling fluid injected from the cooling fluid injection holes s on the periphery of the work W is such that when the work W is in a stopped state, the ranges are respectively indicated by Q1 to Q8. Conversely, it is configured such that there is a range g1 to g8 between the adjacent impact ranges Q that is not subject to the impact of the cooling fluid.

Therefore, at the time of quenching and cooling, the work W is rotating according to the arrow a as shown in FIG. 1C, and the cooling fluid injected toward the rotating work W is applied to the peripheral surface Q of the work W. After the impact, is sent to the rear side of rotation along the peripheral surface according to the arrow, and then reaches the peripheral surface in a range g in which the cooling fluid is not injected, and is released from the injection pressure of the subsequent cooling fluid in the radial direction. Will be spilled. In other words, the cooling fluid after hitting the peripheral surface Q of the work W hardly flows out from the upper and lower end surfaces of the work W or the annular cooler J 'as in the related art, and almost immediately immediately in the radial direction. Will be spilled.

Therefore, regardless of whether the peripheral surface of the work W is a parallel surface or a non-parallel surface, as long as the heating temperature and the heating depth of the work W are maintained at predetermined values, the surface to be heated is uniform in the width direction. Quenched under conditions.

(Experimental example) In order to confirm the effect of the present invention, the inventor performed the following experiment.

☆ Specimen: V roller Material; S45C Dimensions: Large diameter part φ250mm Small diameter part φ190mm Shaft length 250mm ☆ Heat treatment: The above specimen was quenched and tempered according to the following conditions.

Quenching: After heating using a five-turn heating coil indicated as C in FIG. 2 (a), cooling according to the present invention was performed to form a quenched layer indicated by double oblique lines H.

Power source 3KHz / 540KW Heating time 60sec Cooling fluid PVA 0.1% solution Tempering; Electric furnace tempering Temperature 300 ° C Time 3Hr ☆ Accuracy test: Specimens subjected to the above heat treatment were subjected to a hardness measurement test. The measurement positions are shown as I, B, and C in FIG. 2 (b).

The test results were obtained on a graph in which the ordinate represents the hardness (Hv) and the abscissa the distance from the surface (mm). FIG. 2 (c) shows a hardness curve at the position a, and FIG. 2 (d) shows a hardness curve at the position b and c.

From FIGS. 2 (c) and 2 (d), formation of a uniform hardened layer over the entire width direction was confirmed.

From the above experimental results, when using the conventional cooling method,
The central part of the specimen, which is recessed from both end faces and the cooling fluid easily stays, and thus the possibility of uneven baking is likely,
In the method of the present invention, it was confirmed that there was no stagnation of the cooling fluid, and the cooling fluid after the peripheral impact immediately flowed out in the radial direction over the entire width direction, and as a result, the uniformity of the quenched layer was guaranteed in the entire width direction. .

(Other Embodiments) In the above embodiment, eight coolers J were arranged at an angle of 45 ° using eight coolers J. However, the number of coolers J depends on the outer diameter of the work W.
…… For example, if the external shape is large, it will be large, if it is small, it will be small ………
It will increase or decrease.

Further, the shape of the cooler J is not limited to a cylinder, and there is no problem even if the shape is square.

(Effects of the Invention) According to the present invention, one-shot quenching of the peripheral surface of a rotating body having a quenching width somewhat large ensures a uniform quenching finish over the entire quenching width, and contributes to improvement of quenching technology. It is.

[Brief description of the drawings]

FIGS. 1 (a) and 1 (b) are a partial cross-sectional front view and a plan view, respectively, of an apparatus according to an embodiment of the present invention in accordance with the method of quenching and cooling a rotating body, and FIG. FIG. 2 (a) is a partial cross-sectional front view showing a quenched state of a test piece in an experimental example, FIG. 2 (b) is a partial cross-sectional view of the test piece showing a hardness measurement position, Second
FIGS. 3 (c) and 3 (d) are diagrams showing the results of a hardness measurement test, and FIGS. 3 (a) and 3 (b) are front views showing a conventional quenching and cooling method.

Claims (1)

(57) [Claims] 1. A cylinder having an axis parallel to the axis of the above-mentioned rotating member in rapid cooling following heating in the case of one-shot quenching of the peripheral surface of the rotating member, which is the rotating member, relatively widely along the axial direction. A plurality of coolers each composed of a body are disposed at equal angles on a circumference that is separated from the peripheral surface of the member by a predetermined distance so as to maintain a predetermined distance between adjacent members, and each member of the cooler is provided. The peripheral surface of the member of the cooling fluid injected from the cooling fluid injection hole formed in the opposing wall surface is configured to maintain a predetermined distance from the adjacent peripheral region, and the periphery of the member is rotated while rotating the member. By hitting the cooling fluid from the cooling fluid injection hole to the surface, the cooling fluid after hitting the peripheral surface of the member is sent to the rotation rear side along the peripheral surface of the member,
A quenching cooling method for a rotating body, wherein the rotating body is set to escape from a gap between adjacent coolers.