Band saw blade and torsion angle processing method thereof

Abstract

The present invention discloses a band saw blade and a method for processing the torsion angle thereof. The method comprises defining a three-dimensional coordinate system and a straight line L; controlling a processing tool to move to an initial position, wherein the initial position refers to a position in which the working surface of the processing tool coincides with the straight line L and the lowest point of the working surface is located at point A, which is located on the straight line L and above the origin O; controlling the band saw blade to move along the X-axis so that the tip of the tooth to be ground of the band saw blade is located at the origin O; determining the type of tooth to be ground; and controlling the rotation and movement of a grinding wheel based on the type of tooth to be ground to achieve torsion angle processing. The present invention achieves torsion angle processing control by controlling the deflection angle of the grinding wheel, greatly improving the processing accuracy of the torsion angle, thereby improving the performance and stability of the band saw blade.

Description

Technical Field

[0001] The present invention belongs to the technical field of band saw blade processing, and in particular relates to a band saw blade and a method for processing a torsion angle thereof. Background Art

[0002] For split-tooth band saw blades, the teeth typically consist of center teeth, left-hand teeth, and right-hand teeth. These three types of teeth are arranged in a cyclic pattern, such as center teeth, left-hand teeth, and right-hand teeth (i.e., three teeth per group). For the skew teeth (including left-hand and right-hand teeth), the angle between the line on which the tooth edge lies and the normal to the band saw blade's forward motion forms a torsion angle. The definition of torsion angle can be found in the patent document "A Band Saw Blade and Method of Manufacturing Thereof" (Granted Publication No. CN109311107B).

[0003] The torsion angle of the band saw blade is an important factor affecting the cutting performance of the band saw blade. The specific effects include:

[0004] (1) It helps to reduce the main cutting force: Due to the existence of the torsion angle, during the sawing process, the main cutting force (the main cutting force of sawing refers to the resistance parallel to the forward direction of the band saw blade) will form a normal component at the eccentric tooth edge. The existence of this component reduces the main cutting force. Obviously, increasing the torsion angle helps to reduce the main cutting force. The effect of the torsion angle on the main cutting force can be found in the Hunan University Master of Engineering thesis "Sawing Simulation and Tooth Profile Parameter Optimization of Bimetallic Band Saw Blades".

[0005] (2) It is conducive to chip removal: The sawing cutting method has a chip removal problem. The sawing chips are either stored in the tooth groove until the saw teeth move out of the workpiece, or discharged through the gap between the band saw blade and the cutting slot. The torsion angle can guide the sawdust (or chips) generated by the offset cutting to move toward the gap between the band saw blade and the cutting slot, which is conducive to chip removal and reduces the number of chips in the tooth groove, thereby promoting chip removal.

[0006] Because the torsion angle significantly impacts the cutting performance of a band saw blade, its precise control is crucial for both improving performance and stabilizing blade quality. For example, the consistency of the torsion angles of the different offset teeth within a band saw blade, as well as the symmetry of the torsion angles of the left and right offset teeth, significantly impact the blade's performance. Current band saw blade processing methods rely on the torsion angle being determined through the tooth splitting process. However, this is dependent on numerous factors, including the amount of tooth splitting, clamping height, the striking position of the tooth splitting die, and the design of the tooth splitting die. These factors make controlling the torsion angle through the tooth splitting process extremely difficult. Typically, the torsion angle of a band saw blade varies within a wide range of 1° to 5°. For example, the patent document - A band saw blade and its manufacturing method (authorization publication number CN109311107B) proposes a band saw blade with a torsion angle of 5.5 to 6.5°, with a variation range of 1°, and does not disclose how to obtain the torsion angle. Another example is the patent document - Method of making a sawblade tooth form (publication number US05775181A), which discloses a method for forming saw teeth of a band saw blade. This method helps to obtain a larger torsion angle, but the teeth still need to be separated after forming. Therefore, although this method can obtain a larger torsion angle, it cannot achieve precise control of the torsion angle. Summary of the Invention

[0007] The object of the present invention is to provide a band saw blade and a method for processing the torsion angle thereof, so as to solve the problem that the traditional band saw blade processing method cannot achieve precise control of the torsion angle processing, resulting in low performance and stability of the band saw blade.

[0008] The present invention solves the above technical problems through the following technical solutions: A method for processing the torsion angle of a band saw blade comprises the following steps:

[0009] Step 1: Define a three-dimensional coordinate system and a straight line L, wherein the three-dimensional coordinate system has the line connecting the tooth tips of the band saw blade to be processed as the X-axis, the width direction of the band saw blade as the Z-axis, and the thickness direction of the band saw blade as the Y-axis. The intersection of the straight line L and the X-axis is the coordinate origin O, and the angle between the straight line L and the Z-axis is equal to the rake angle of the band saw blade;

[0010] Step 2: Control the processing tool to move to an initial position, wherein the initial position means that the working surface of the processing tool coincides with the straight line L and the lowest point of the working surface is at point A, and point A is located on the straight line L and above the origin O;

[0011] Step 3: Control the band saw blade to move along the X-axis so that the tooth tip of the to-be-ground tooth of the band saw blade is located at the origin O;

[0012] Step 4: Determine the type of the saw teeth to be ground;

[0013] Step 5: According to the type of saw tooth to be ground, the working surface is first controlled to rotate about the straight line L as the axis so that the angle between the straight line L' on the working surface and the Y axis is equal to the torsion angle, and then the working surface is controlled to move along the straight line L from point A to point B and then back to point A, thereby completing the torsion angle processing of the saw tooth to be ground;

[0014] The straight line L' is perpendicular to the straight line L and passes through the center point of the working surface. The point B is located on the straight line L and below the origin O.

[0015] Step 6: Repeat steps 3 to 5 until the torsion angle processing of all the teeth to be ground on the saw blade is completed.

[0016] Furthermore, the three-dimensional coordinate system takes the forward direction of the band saw blade as the positive direction of the X axis, the direction from the tooth tip to the tooth back as the positive direction of the Z axis, and the upward direction when looking down at the band saw blade from the tooth tip as the positive direction of the Y axis.

[0017] Furthermore, the processing tool is a grinding wheel, and the movement and rotation of the grinding wheel are controlled by an electrical control module and a servo drive mechanism.

[0018] Furthermore, a transmission mechanism is used to control the movement of the band saw blade along the X-axis.

[0019] Furthermore, the transmission mechanism is a pusher claw, and the movement of the band saw blade is controlled by controlling the pusher claw stroke, wherein Pmax<pusher claw stroke S<Pmax+Pmin, Pmax is the maximum tooth pitch, and Pmin is the minimum tooth pitch.

[0020] Furthermore, the types of saw teeth to be ground include middle teeth, left-biased teeth and right-biased teeth.

[0021] Furthermore, when the saw tooth to be ground is a middle tooth, the angle between the straight line L' and the Y axis is equal to 0°;

[0022] When the sawtooth to be ground is a right-biased tooth, the angle between the straight line L' and the positive direction of the Y axis is equal to -TA;

[0023] When the sawtooth to be ground is a left-biased tooth, the angle between the straight line L' and the positive direction of the Y axis is equal to +TA;

[0024] The positive direction of the Y-axis refers to the upward direction when looking down at the band saw blade from the tooth tip. Taking the positive direction of the Y-axis as the reference, the clockwise rotation direction is defined as positive, and the counterclockwise rotation direction is defined as negative, and |TA| = 2 to 8°.

[0025] Furthermore, the distance from the origin O to point B is determined by the tooth structure of the sawtooth.

[0026] Furthermore, for tooth profiles of 2 / 3TPI and above, the distance from the origin O to point B is 1 to 2 mm.

[0027] Based on the same concept, the present invention further provides a band saw blade, comprising a saw blade body and saw teeth provided on the saw blade body, wherein the torsion angle of the saw teeth is obtained by processing the band saw blade torsion angle processing method as described above.

[0028] Beneficial effects

[0029] Compared with the prior art, the advantages of the present invention are:

[0030] The present invention provides a band saw blade and a method for processing the torsion angle thereof. The torsion angle of the saw teeth is only related to the deflection angle of the grinding wheel and is unrelated to other factors such as the number of teeth, the clamping height, the striking position of the tooth division mold, the design of the tooth division mold, etc. The torsion angle is controlled by controlling the deflection angle of the grinding wheel, which greatly improves the processing accuracy of the torsion angle, thereby improving the performance and stability of the band saw blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 is a flow chart of a method for processing a torsion angle of a band saw blade according to an embodiment of the present invention;

[0033] Figure 2 is a schematic diagram of a three-dimensional coordinate system and a straight line L in an embodiment of the present invention;

[0034] Figure 3 In the embodiment of the present invention Figure 2 A partial enlarged view of the coordinate origin O;

[0035] Figure 4 is a diagram showing the relationship between the grinding wheel and the Y-axis when machining the torsion angle of the middle teeth in an embodiment of the present invention;

[0036] Figure 5 : is a positional relationship diagram of the straight line L and the straight line L' on the working surface of the grinding wheel in an embodiment of the present invention; wherein point O' is the center point of the working surface, and point A' is the lowest point of the working surface;

[0037] Figure 6 Schematic diagram of middle gear grinding in an embodiment of the present invention;

[0038] Figure 7 7 is a diagram showing the relationship between the grinding wheel and the Y-axis when machining the torsion angle of the right-hand deflected tooth according to an embodiment of the present invention;

[0039] Figure 8Schematic diagram of right-biased tooth grinding in an embodiment of the present invention;

[0040] Figure 9 Schematic diagram of the torsion angle of the right-biased tooth in an embodiment of the present invention;

[0041] Figure 10 7 is a diagram showing the relationship between the grinding wheel and the Y-axis when machining the torsion angle of the left-biased tooth in an embodiment of the present invention;

[0042] Figure 11 Schematic diagram of the torsion angle of the left-biased tooth in an embodiment of the present invention.

[0043] Among them, 1-band saw blade, 11-ground saw teeth, 12-unground saw teeth, 13-saw teeth to be ground, 2-grinding wheel. DETAILED DESCRIPTION

[0044] The following is a clear and complete description of the technical solutions of the present invention in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0045] The following specific embodiments are used to describe the technical solution of the present application in detail. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0046] The embodiment of the present invention provides a method for processing the torsion angle of a band saw blade, which uses a grinding wheel to grind the rake surface of a band saw blade that has been processed with offset teeth, so as to achieve the processing of the torsion angle. Figure 1 As shown, the band saw blade torsion angle processing method includes the following steps:

[0047] Step 1: Define the three-dimensional coordinate system and line L.

[0048] The band saw blade 1 is mounted on a processing platform. During processing, the band saw blade 1 is clamped by a fixture. During movement, the band saw blade 1 is transported by a conveying mechanism. The fixture and the conveying mechanism are existing structures.

[0049] like Figure 2 As shown, the tooth tip line of the band saw blade 1 on the processing platform (i.e., the band saw blade 1 to be processed) is the X axis, the width direction of the band saw blade 1 is the Z axis, the thickness direction of the band saw blade 1 is the Y axis, and the straight line L (i.e., Figure 2The intersection of the dashed line (in the figure) and the X-axis is defined as the coordinate origin O, and the angle between line L and the Z-axis is equal to the rake angle of band saw blade 1. The rake angle of band saw blade 1 refers to the angle between the front face and base of the untoothed teeth. For details, refer to the standard GBT 21954.1-2008 Metal Cutting Band Saw Blades - Part 1 - Terminology.

[0050] In this embodiment, the forward direction of the band saw blade 1 (for example, from right to left) is the positive direction of the X axis, the direction from the tooth tip to the tooth back is the positive direction of the Z axis, and the upward direction when looking down at the band saw blade 1 from the tooth tip is the positive direction of the Y axis. Figure 2 shown.

[0051] The defined straight line L is the moving trajectory of the processing tool, so the straight line L should be within the travel range of the processing tool.

[0052] Step 2: Control the processing tool to move to the initial position.

[0053] In this embodiment, the processing tool is a grinding wheel 2, that is, the grinding wheel 2 is controlled to move to the initial position, wherein the initial position means that the working surface of the grinding wheel 2 coincides with the straight line L and the lowest point A' of the working surface is located at point A, and point A is located on the straight line L and above the origin O, so as to ensure that there is no interference between the grinding wheel 2 and the teeth of the band saw blade 1 and a complete plane is obtained on the rake surface, as shown in FIG. Figure 3 shown.

[0054] The movement and rotation of grinding wheel 2 are controlled by an electrical control module and a servo drive mechanism, which uses a servo motor as its power source. Driven by pulse signals from the electrical control module, the servo drive mechanism drives grinding wheel 2 to move and rotate about line L, adjusting its position and deflection angle.

[0055] Step 3: Control the band saw blade 1 to move along the X-axis so that the tooth tip of the to-be-ground tooth 13 of the band saw blade 1 is located at the origin O.

[0056] In this embodiment, a pusher dog is used as the transmission mechanism for the band saw blade 1. Under the control of the electrical control module, the pusher dog is used to transmit the band saw blade 1, where Pmax < pusher dog stroke S < Pmax + Pmin, where P represents the pitch of the band saw blade 1, i.e., the distance between two adjacent teeth; Pmax is the maximum pitch; and Pmin is the minimum pitch. Depending on the pitch, band saw blades 1 can be either uniform or variable pitch. For uniform pitch band saw blades 1, the distance between any two adjacent teeth is constant, meaning P is a fixed value. For variable pitch band saw blades 1, P varies.

[0057] The movement of the band saw blade 1 is controlled by controlling the pusher dog's stroke. The distance between the pusher dog's starting point and its ending point on the X-axis is the pusher dog's stroke. After the tip of the tooth 13 to be ground is brought to the origin O, the pusher dog returns to its starting point, allowing it to move the next tooth to the origin O when the next tooth undergoes torsion angle processing.

[0058] Step 4: Determine the type of the saw teeth 13 to be ground.

[0059] The types of teeth 13 to be ground include center teeth, left-hand teeth, and right-hand teeth. The teeth on the band saw blade 1 are typically arranged in a repeating pattern of multiple cyclic units, each consisting of a different tooth type. For example, each cyclic unit may be center teeth, left-hand teeth, and right-hand teeth, or center teeth, left-hand teeth, right-hand teeth, left-hand teeth, and right-hand teeth.

[0060] Step 5: Control the movement of the grinding wheel 2 according to the type of the saw teeth 13 to be ground, so as to achieve the processing of the torsion angle.

[0061] like Figure 4 As shown, for the middle tooth, the servo drive mechanism first controls the working surface of the grinding wheel 2 to rotate around the straight line L as the axis to adjust the deflection angle of the working surface so that the angle between the straight line L' on the working surface and the Y axis is equal to the torsion angle. Then the working surface is controlled to move from point A to point B along the straight line L (that is, the lowest point A' of the working surface moves to point B to complete the grinding of the front cutting edge of the middle tooth) and then returns to point A along the straight line L, thus completing the torsion angle processing of the middle tooth. Among them, the straight line L' is perpendicular to the straight line L and the straight line L' passes through the center point O' of the working surface (as shown in FIG. Figure 5 As shown), point B is on the straight line L and below the origin O (as shown Figure 3 shown).

[0062] The distance from O to B is determined by the sawtooth profile. This ensures that the rake face of the sawtooth 13 being ground is ground (i.e., a completely flat surface is achieved) and that the grinding wheel 2 does not contact the tooth groove. For tooth profiles of 2 / 3 TPI and above, the distance from O to B is 1 to 2 mm.

[0063] For the middle tooth, the torsion angle is 0°, that is, the straight line L' is parallel to the Y axis, such as Figure 6 Schematic diagram of middle tooth grinding shown.

[0064] like Figure 7 As shown in the figure, for the right-biased tooth, the servo drive mechanism is used to first control the working surface of the grinding wheel 2 to rotate around the straight line L, so that the angle between the straight line L' on the working surface and the positive direction of the Y axis is equal to the torsion angle + TA, and then the working surface is controlled to move along the straight line L from point A to point B and then return to point A along the straight line L (i.e., A-B-A), thus completing the torsion angle processing of the right-biased tooth.

[0065] In this embodiment, the upward direction when looking down at the band saw blade 1 from the tooth tip is the positive direction of the Y axis. Figure 7 As shown in the figure, with the positive direction of the Y-axis as the reference, the clockwise rotation direction is defined as positive and the counterclockwise rotation direction is defined as negative. Therefore, the torsion angle of the right-hand deflection tooth is -TA, and the torsion angle of the left-hand deflection tooth is +TA.

[0066] For left-biased and right-biased teeth, the torsion angle |TA|=2-8°, preferably |TA|=3-6°, and the specific value of the torsion angle can be set according to the requirements. Figure 8 The right-hand side gear grinding diagram shown in the figure and Figure 9 Schematic diagram of the torsion angle of the right-biased tooth shown.

[0067] like Figure 10 As shown, for the left-biased tooth, the servo drive mechanism first controls the working surface of the grinding wheel 2 to rotate around the straight line L, so that the angle between the straight line L' on the working surface and the positive direction of the Y axis is equal to the torsion angle -TA. Then, the working surface is controlled to move along the straight line L from point A to point B and then back to point A along the straight line L (i.e., A-B-A), thus completing the torsion angle processing of the left-biased tooth. Figure 11 Schematic diagram of the torsion angle of the left-biased tooth shown.

[0068] Step 6: Repeat steps 3 to 5 until the torsion angle processing of all the teeth 13 to be ground on the saw blade is completed.

[0069] The method of the present invention can be used for the processing of band saw blade coils by adding a discharge mechanism in front of the grinding equipment and a collection mechanism behind the grinding equipment to form a torsion angle processing production line, and then adding a guide mechanism at the appropriate position of the production line. The method of the present invention can also be used for the processing of band saw blade root strips by adding a band saw blade support structure to the grinding equipment. The method of the present invention can be used for both split-tooth bimetallic band saw blades and split-tooth carbide band saw blades. If used for split-tooth bimetallic band saw blades, the band saw blades need to be quenched and tempered before torsion angle processing.

[0070] The method of the present invention enables precise control of the torsion angle. The grinding wheel is controlled by a servo drive mechanism, theoretically enabling torsion angle control with an accuracy of ±0.1° or even higher, helping to improve the performance and stability of band saw blades. The present invention accurately obtains the required torsion angle and allows the torsion angle to be designed based on the operating conditions of the band saw blade, improving the targeted use of the band saw blade. The present invention can accelerate research on the effect of torsion angle on band saw blades, significantly advancing the development of sawing theory.

[0071] The above disclosure is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field can easily think of changes or modifications within the technical scope disclosed in the present invention, and they should all be covered by the scope of protection of the present invention.

Claims

1. A method for processing the torsion angle of a band saw blade, characterized in that: The following steps are involved: Step 1: Define a three-dimensional coordinate system and a straight line L, wherein the three-dimensional coordinate system has the line connecting the tooth tips of the band saw blade to be processed as the X-axis, the width direction of the band saw blade as the Z-axis, and the thickness direction of the band saw blade as the Y-axis. The intersection of the straight line L and the X-axis is the coordinate origin O, and the angle between the straight line L and the Z-axis is equal to the rake angle of the band saw blade; Step 2: Control the processing tool to move to an initial position, wherein the initial position means that the working surface of the processing tool coincides with the straight line L and the lowest point of the working surface is at point A, and point A is located on the straight line L and above the origin O; Step 3: Control the band saw blade to move along the X-axis so that the tooth tip of the to-be-ground tooth of the band saw blade is located at the origin O; Step 4: Determine the type of the saw teeth to be ground; Step 5: According to the type of saw tooth to be ground, the working surface is first controlled to rotate about the straight line L as the axis so that the angle between the straight line L' on the working surface and the Y axis is equal to the torsion angle, and then the working surface is controlled to move along the straight line L from point A to point B and then back to point A, thereby completing the torsion angle processing of the saw tooth to be ground; The straight line L' is perpendicular to the straight line L and passes through the center point of the working surface. The point B is located on the straight line L and below the origin O. Step 6: Repeat steps 3 to 5 until the torsion angle processing of all the teeth to be ground on the saw blade is completed.

2. The method for processing the torsion angle of a band saw blade according to claim 1, wherein: The three-dimensional coordinate system takes the forward direction of the band saw blade as the positive direction of the X axis, the direction from the tooth tip to the tooth back as the positive direction of the Z axis, and the upward direction when looking down at the band saw blade from the tooth tip as the positive direction of the Y axis.

3. The method for processing the torsion angle of a band saw blade according to claim 1, wherein: The processing tool is a grinding wheel, and the movement and rotation of the grinding wheel are controlled by an electrical control module and a servo drive mechanism.

4. The method for processing the torsion angle of a band saw blade according to claim 1, wherein: The transmission mechanism is used to control the movement of the band saw blade along the X axis.

5. The method for processing the torsion angle of a band saw blade according to claim 4, wherein: The transmission mechanism is a pusher claw, and the movement of the band saw blade is controlled by controlling the pusher claw stroke, wherein Pmax<pusher claw stroke S<Pmax+Pmin, Pmax is the maximum tooth pitch, and Pmin is the minimum tooth pitch.

6. The method for processing the torsion angle of a band saw blade according to claim 1, wherein: The types of saw teeth to be ground include middle teeth, left-biased teeth and right-biased teeth.

7. The method for processing the torsion angle of a band saw blade according to claim 6, wherein: When the saw tooth to be ground is a middle tooth, the angle between the straight line L' and the Y axis is equal to 0°; When the sawtooth to be ground is a right-biased tooth, the angle between the straight line L' and the positive direction of the Y axis is equal to -TA; When the sawtooth to be ground is a left-biased tooth, the angle between the straight line L' and the positive direction of the Y axis is equal to +TA; The positive direction of the Y-axis refers to the upward direction when looking down at the band saw blade from the tooth tip. Taking the positive direction of the Y-axis as the reference, the clockwise rotation direction is defined as positive, and the counterclockwise rotation direction is defined as negative, and |TA| = 2 to 8°.

8. The method for processing the torsion angle of a band saw blade according to claim 1, wherein: The distance from the origin O to point B is determined by the tooth structure of the sawtooth.

9. The method for processing the torsion angle of a band saw blade according to claim 8, wherein: For tooth profiles of 2 / 3TPI and above, the distance from the origin O to point B is 1 to 2 mm.

10. A band saw blade comprising a saw blade body and saw teeth provided on the saw blade body, characterized in that: The torsion angle of the saw teeth is obtained by processing the torsion angle of a band saw blade according to any one of claims 1 to 9.

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