JPH0355114A - Beveling device for preventing crack of band saw - Google Patents

Abstract

PURPOSE:To omit the annealing and hardening of a band saw and to drastically curtail a work cost by arranging a grinding wheel whose diameter is larger than the circular arc of a tooth bottom part in a band saw more than one set so that the center is aligned to the lowest part of the tooth bottom part and linking an operation means notching to the corner of the tooth bottom part with a specific inclination to these grinding wheels. CONSTITUTION:In the case of execution a one step beveling alternately, a grinding wheel 6 is inclined at 45 deg. by operation means (12, 14) of the left side first and returned to a constant position after notching to the corner of the left side of the tooth bottom part (b) of a band saw 1, at the time when the band saw 1 fed intermittently is stopped by corresponding the tooth bottom part (b) to a set of grinding wheels 6, 7 arranged corresponding. The grindstone wheel 7 is then inclined at 45 deg. by the operation means (13, 15) of the right side, notched to the corner of the right side of the tooth bottom part 6 and returned to the constant position. By repeating such operations the beveling of 45 deg. inclined angle is executed on the left corner and right corner of the same tooth bottom part (b).

Description

[Detailed Description of the Invention] A2 Objective of the Invention (Industrial Ichikawa Part)!f> The present invention is an apparatus for performing crack-preventing processing on a band saw. Relating to a device that applies chamfering force by grinding.

(Prior art) Originally, with a band saw, stress is concentrated at the lower part of the teeth during sawing, so stress is generated in this part. This causes cracks, and this crack can be prevented by chamfering the bottom of the tooth, according to the Publication of Utility Models in 1977-47.
17 and Japanese Patent Application Laid-Open No. 51-230701.

<Problem to be solved by the invention> However, the above-mentioned Utility Model Publication No. 47-47]. In the method disclosed in Publication No. 7, the tooth bottom portion of the band saw, which is in a relatively soft state before hardening, is compressed by a round groove of a gear to form a surface, and then the band saw is hardened and used. , Each time the chamfered portion described above decreases due to Hitachi's repetition, the process of tempering the band saw, chamfering, and then hardening after chamfering must be repeated, which increases the cost of hardening and annealing. It is too impractical, and although the document published in Japanese Patent Application Laid-Open No. 59-230701 suggests that the handle can be easily formed by grinding, it does not disclose any means for doing so. Therefore, this was also not of practical use.

The present invention has been made in response to this current situation, and by cutting into the tooth base at different inclination angles with a plurality of grinding wheels having a diameter larger than the tooth base of the band saw, surface smoothness is achieved to prevent cracking. The purpose is to provide a device that can perform polishing at low cost.

stomach. Summary of the Invention (Means for Solving the Problems) The means of the present invention for achieving the above-mentioned object is to use a grinding wheel having a diameter larger than the arc of the tooth base in a band saw. At the side of a chamfering device for preventing cracks of a band saw, one or more sets are arranged so that the center is aligned with the lowest part, and these grinding wheels are linked with operating means for cutting at a predetermined slope at the corner l of the tooth bottom part. be.

The grinding wheel used in this device has a diameter larger than the toe arc of the tooth base in order to reduce the tooth base of the band saw so that the lowest part is the largest and decreases as the distance from this part increases. Select a grinding wheel that is twice or several times larger, and position this grinding wheel so that its center matches the lowest part of the tooth base3 to enable chamfering under the conditions described above. For single-stage chamfering, use two or more sets of grinding wheels, and for multi-stage chamfering, use two or more sets of grinding wheels.

The operation means for cutting the above-mentioned grinding wheel into the corner of the tooth low part of the bandsaw is to tilt the grinding wheel held in a fixed position so as not to interfere with the feeding of the band saw. angle l
＼It cuts diagonally and chamfers this part. In the case of the one-stage chamfer described above, the chamfer angle is set to 45 degrees, and in the case of the two-stage chamfer, each grinding wheel In the case of a three-stage grinding wheel, the chamfer angle by each grinding wheel is set to be 15 degrees. The effect of stress dispersion improves as the device approaches ′! Since the R structure becomes complicated and the machining time increases, one-stage or two-stage chamfering is generally adopted, and the operating means is supported by supporting the grinding wheel on a swinging arm. A cam, crank, 4 cylinders, etc. are attached to this swinging arm. Either other reciprocating means are linked and these reciprocate between the home position and the cutting position, or a spring is used to move the grinding wheel from the home position to the cutting position, and then it is returned from the cutting position to the home position. Using the reciprocating means described above, the left corner machining and right corner machining are arranged correspondingly and operated alternately, and the left corner and right corner of the same tooth bottom are alternately machined. Or, even if the left-hand corner machining and right-hand corner machining are operated at the same time, their positions are shifted so that they do not interfere with each other, so that chamfering on the left and right sides of different tooth bottom parts can be performed at the same time. This is to determine the operation timing of each operating means.

(Function) As mentioned above, when the side cutting device for preventing cracks is used for alternating single-stage cutting, the band saw that is fed intermittently is
When stopping with the bottom part set against a set of grinding wheels arranged in a 6-way position, first, the operating means on the k side sets the grinding wheel at 45
Tilt the band saw at a 45° angle, cut into the left corner of the lower tooth of the bandsaw, return it to the normal position, and then use the operating means on the right to turn the grinding wheel 45°.
If you repeat the operation of making a cut at the right corner of the tooth base with an inclination and then returning it to the normal position, a 45° inclination angle will be cut between the left and right corners of the same tooth base. Moreover, this chamfer has a preferable shape in terms of the stress dispersion effect, which is greatest at the lowest part of the tooth base and decreases as the distance from this part increases.

In addition, when performing two-step chamfering alternately, when the band saw that is being fed intermittently stops after grinding the lower part of the teeth between two sets of grinding wheels that are set opposite each other so as not to interfere with each other, the left side is first chamfered. Using the operating means, tilt the front grinding wheel by 60 degrees and the rear grinding wheel by 30 degrees, cut into the left corner of the tooth base of the bandsaw, and then return to the normal position. If you repeat the operation of tilting the front and rear grinding wheels by 60 degrees and the rear grinding wheel by 30 degrees to cut into the corners of the lower teeth of the band saw, the left and right corners of the lower teeth of the band saw will be cut by 30 degrees. A two-step surface 1 is provided with two slope angles, and this chamfering is preferable in view of the effect of dispersing stress, which is greatest at the lowest part of the tooth base and decreases as the distance from this part increases.

In addition, when performing surface smoothing by this grinding C, the drive motor of the grinding wheel is housed in the F stage, and the grinding wheel is oscillated in the axial direction to perform grinding using its full width. If this is done, the grinding wheel can be dressed during grinding to ensure accurate grinding at all times, but since this is a method commonly used in the industry, a detailed explanation will be provided. is omitted.

(Example) Hereinafter, an example of an apparatus related to the present invention will be described based on the drawings.

Figures 1 and 2 show examples of single-stage chamfering. , these saws (J.'(
21, each having an arc-shaped tooth bottom part b,
Since stress concentration occurs in these tooth low portions b7 during sawing and cracks are likely to occur, the inclined chamfers 2 are applied to each tooth low portion b by grinding with a grinding wheel (described later) as shown in Fig. 5. It is formed so that the lowest part of the lower part b is the maximum, and decreases as the distance from this part increases.

Reference numeral 3 designates the feeding member of the band saw 1, which is attached to a lever 5 driven by a cam 4 as shown in FIG. Make sure to intermittent feed every minute.

Reference numerals 6 and 7 denote a pair of grinding wheels, each having a diameter approximately three times the arc of the tooth base b of the band saw 1, and are supported by a pair of correspondingly provided swinging arms 8 and 9. Motors 10 and 11
When the swinging arms 8 and 9 are swung inward by the operating means described later, the grinding wheels 6 and 7 are tilted at an angle of 456 to the left and right corners of the tooth base b of the band saw 1. It is hit by a 45° bevel and is returned to its home position as it swings outward.

12. 13 and 14. Reference numeral 15 denotes a spring and a cam as operating means for causing the above-mentioned grinding wheels 6 and 7 to swing inward and swing outward, and springs 12 and 13 support the grinding wheels 6 and 7. The swing arms 8 and 9 are connected to a stopper 16 at the bottom thereof.
17, and move the grinding wheels 6 and 7 to the third position.
As shown in Figures and Figure 4, the tooth bottom l
], and the cams 14, 1. '
1 serves to return the swinging arms 8 and 9 that have been swung inward to their normal positions, and the inward and outward swinging of the swinging arms 8 and 9 is shown in FIG. The symmetrical arrangement of the arms 14 and 15 allows for alternating operation.

In the apparatus shown in the above embodiment, the band saw 1 is fed by the feeding member 2, and stopped when the tooth bottom portion b of the band saw is opposed to the grinding wheels 6 and 7, and the left swinging arm 8 is moved to the grinding wheel by the spring 12. It is swung inwardly until it hits the stopper 16, then returned to the normal position by the cam 14. Along with this, the right swinging arm 9 is swung inwardly by the spring 13 until it hits the stopper 17/\\, and then, The action of returning to the normal position was repeated.

As a result, as shown in FIGS. 3 and 4, a surface convergence 2 of 45° is formed at the left and right corners of each tooth base b of the bandsaw, as shown in FIG. It was formed in a favorable state for the stress dispersion effect, which has a maximum part and decreases as the distance from this part increases.

Incidentally, upon chamfering, a slight flat portion A is left at the center of the thickness of the tooth base portion b, as shown in FIG.

7 and 8 of the drawings show an embodiment of two-stage surface feeding, in which the band saw (2) is intermittently fed by the same feeding member 2 as in the previous embodiment, and the two teeth of the band saw (1) are part b to 2
Set of grinding wheels 18. 19 and 20. 21 and the swinging arm 22
, 23 and 24. 25 and a motor 26 supported by
27, 28. The swinging arms 22, 23 and 24. Kano as a means of operation in 25, 30. 31 and 32. 33 and springs 34, 35 and 36. 37, and the cams 30 and 31 cause the swinging arms 22. 23 inward by 60 degrees and turn the grinding wheel 18.
19 to the left and right corners of the tooth base portion b at an inclination angle of 60° as shown in FIGS. 9 and 10.
This causes the swinging arms 24 and 25 to swing inward by 30 degrees, and the grinding wheel 18. As shown in FIGS. 13 and 14, springs 34, 35, and 36. 37
are the swinging arms 22, 23 and 2/l, 2 that have been swung inward.
5 to its normal position.

The device shown in the embodiment described above has a band saw 1-
, and stop when the tooth bottom part b corresponds to the grinding wheels 1819 and 2hi, 21, and! The front swinging arm 22 on which side is swung inward by 60 degrees by the cam 3 (), and the rear swing arm 24 is swung inward by 30 degrees by the cam 32, and then the spring 34,
3B returns the swinging arms 22 and 24 to their home positions, and accordingly, the front swinging arm 23 on the right side is swinged inward by 60° by the cam 31, and the rear swinging arm 25 is swinged inward by 30° by the cam 33. After that, the swinging arms 23 and 2 are moved by the springs 35 and 37.
! ] was repeated to return it to its normal position.

11 As a result, 30
The two-stage surface convergence 22' having an inclination of .degree. is preferably formed in such a manner that the lowest portion of the tooth base portion b is at its maximum, and the stress dispersion effect decreases as the distance from this portion increases.

In addition, even in this two-step chamfering, a slight flat portion A is left at the center of the thickness of the tooth base portion b.

C. Effects of the Invention The chamfering device for preventing cracks in band saws according to the present invention chamfers the lower corners of the band saw teeth by grinding with a grinding wheel, thereby improving the chamfering process of band saws, which is indispensable in conventional press chamfering. By omitting annealing and hardening, the processing cost can be significantly reduced, and the technique of improving the durability of band saws by chamfering can be made practical.

Chamfering by grinding allows the band saw to maintain its hardened condition at the time of manufacture and exhibits good sawn material performance, and also has the same crack prevention effect by renewing the surface by grinding.

12 It has the following unique effects.

[Brief explanation of drawings]

FIG. 1 is a side view showing a single-stage chamfered embodiment of the device according to the present invention. Figure 2 is a longitudinal sectional front view of the main parts of the same as above. Figure 3~
FIG. 5 is an explanatory diagram of the chamfered state. Figure 6 is a side view of the chamfer. FIG. 7 is a side view showing an embodiment of the two-stage housing. FIG. 8 is a longitudinal sectional front view of the main parts of the same as above. FIG. 9 to FIG. 11 are explanatory diagrams of the first stage surface-containing state. Figure 12 is a side view of the first stage rack. FIGS. 13 to 15 are explanatory diagrams of the second-stage convergence state. Figure 16 is a side view of the second stage of storage. 1: Band saw b: Tooth bottom portions 6.7 and 18. 19, 20, 21: Grinding wheel 12.
13 and 14. 15 and 30. 31, 32, 33: Operation means

Claims (1)

[Claims] One or more sets of grinding wheels having a diameter larger than the arc of the tooth base in a band saw are arranged so that their centers are aligned with the lowest part of the tooth base, and these grinding wheels are provided with a predetermined inclination toward the corner of the tooth base. A chamfering device for preventing cracks in a band saw, characterized in that operating means for cutting are linked.