WO2022022414A1

WO2022022414A1 - Bimetal band saw blade weld joint strength test device and method

Info

Publication number: WO2022022414A1
Application number: PCT/CN2021/108122
Authority: WO
Inventors: 柳寒潇; 易佳文; 贾寓真; 刘国跃
Original assignee: 湖南泰嘉新材料科技股份有限公司
Priority date: 2020-07-31
Filing date: 2021-07-23
Publication date: 2022-02-03
Also published as: CN111940941A; CN111940941B

Abstract

A bimetal band saw blade weld joint strength test device, comprising a compression test machine, a clamp (2) and a top head (4). The compression test machine comprises a base (3), a frame (1) located on the base (3), and a lifting cross beam (2) arranged on the frame; the top head (4) is fixed at the bottom part of the lifting cross beam (2), and the clamp (2) is located below the top head (4); the clamp (2) is provided with a groove (6), fastening screw holes (5) and a positioning through hole (9); the positioning through hole (9) extends along the vertical direction and is used to fix the clamp (2) on the base (3) by means of fastening bolts; the groove (6) is located on a side surface of the clamp (2), and extends along the vertical direction; a band saw blade (10) and a pressure block (8) are contained in the groove (6); and fastening screws in the fastening screw holes (5) abut against the pressure block (8), thereby fixing the band saw blade (10) into the groove (6). The test device makes the direction of a test force parallel to the extension direction of the band saw blade, which is closer to the stress state of a weld joint during the actual use of the band saw blade. The test structure is more accurate. The test device has a simple structure and convenient operation, and may adapt to the test requirements of band saw blades of different specifications. Further relating to a bimetal band saw blade weld joint strength test method.

Description

A bimetal band saw blade welding seam strength testing device and method

technical field

The invention relates to a bimetallic band saw blade welding seam strength testing device and method, belonging to the technical field of band saw blade testing equipment.

Background technique

The bimetallic band saw blade is one of the most commonly used tools in the cutting process. Processed. Obviously, the weld strength after welding has a great influence on the life of the bimetal band saw blade and is one of the key quality indicators. When the band saw blade rotates around the saw wheel and continuously cuts in and out of the workpiece, the sawtooth will bear the stress perpendicular to the width direction. If the strength of the welding seam is not up to the standard and is not enough to withstand this stress, the welding seam will break and the teeth will peel off the back. material phenomenon. When one tooth breaks, the next tooth will bear double the stress, which is also very easy to break. When two consecutive saw teeth break, the third tooth will bear three times the stress, making it easier to break. As a result, the saw tooth continuously breaks in the weld seam, forming so-called pull teeth, causing the entire band saw blade to fail. Therefore, controlling the weld strength is the key task in the manufacture of bimetal band saw blades, which requires the ability to accurately measure the weld strength when the sawtooth is subjected to the normal stress of the rake face.

However, the current method for testing the serration weld strength of a bimetal band saw blade is not testing the strength of the rake face of the serration when it will be subjected to stress along the extension of the band saw blade. Instead, the strength of the weld is determined by applying the test force perpendicular to the plane of the band saw blade and recording the maximum force at which the weld breaks.

The above method is used to detect the strength of the weld. Since the force is applied to the normal direction of the side of the sawtooth, the force-bearing surface of the sawtooth is the rake face during the actual use of the band saw blade, and the force-bearing direction of the sawtooth is along the running direction of the saw blade. The method does not actually reflect the force during the use of the saw blade, which causes the detection result to fail to reflect the actual use performance of the band saw blade.

SUMMARY OF THE INVENTION

In order to overcome the problems existing in the prior art, the present invention provides a device and method for testing the strength of the weld seam of a bimetal band saw blade, so as to better reflect the stress condition of the weld seam during the actual use of the band saw blade. The specific technical scheme is as follows.

A bimetal band saw blade weld strength testing device, characterized in that it includes a compression testing machine, a fixture and a plug, the compression testing machine comprising a base, a frame on the base, and a lifting beam arranged on the frame; the plug be fixed on the bottom of the lifting beam, and the clamp is located below the jack;

The clamp is provided with a groove, a fastening screw hole and a positioning through hole, and the positioning through hole extends in the vertical direction and is used for fixing the clamp on the base through a fastening bolt, and the groove Located on the side of the clamp and extending along the vertical direction, the groove accommodates a band saw blade and a pressure block, and the tightening screw in the tightening screw hole abuts the pressure block to tighten the belt The saw blade is fixed in the groove.

Further, the projection of the positioning through hole on the horizontal plane is a waist-shaped hole.

Further, the plug is a cemented carbide plug.

Further, a plurality of the fastening screw holes are arranged at intervals along the vertical direction.

Further, the height of the pressing block is the same as the height of the groove.

Based on the same inventive concept, the present invention also relates to a method for testing the weld seam strength of a bimetal band saw blade, which adopts the above-mentioned device for testing the weld seam strength of a bimetal band saw blade, and mainly includes the following steps:

Cut the band saw blade into segment samples, put them into the groove of the fixture, and fix the band saw blade sample by pushing the pressing block through the tightening screw;

Adjust the position of the clamp on the base so that the saw teeth of the band saw blade are directly below the head, and tighten the fastening bolts to lock the clamp on the base;

Start the compression testing machine, the head gradually moves to the sawtooth until the sawtooth weld is broken, and the compression testing machine records the force F that breaks the weld; measure the fracture length L, and the thickness of the saw blade is b, then the weld strength σ=F/(L *b).

Compared with the prior art, the present invention changes the application direction of the test force, so that the direction of the test force is parallel to the extension direction of the band saw blade, which is closer to the stress state of the welding seam during the actual use of the band saw blade, and the test structure is more precise. The testing device of the invention is simple in structure and convenient in operation, and can adapt to the testing requirements of band saw blades of different specifications. The present invention uses σ=F/(L*b) to characterize the weld strength per unit area, which is more accurate and reliable than that in the prior art, the weld strength only judges the strength according to the fracture force.

Description of drawings

Fig. 1 is the schematic diagram of the test apparatus of the present invention;

Fig. 2 is the enlarged schematic diagram of the circle part in Fig. 1;

Figure 3 is a schematic diagram of the positional relationship between the plug and the band saw blade.

In the picture: 1-frame 2-lifting beam 3-base, 4-head 5-fastening screw hole 6-groove 7-fixture 8-pressing block 9-positioning through hole, 10-band saw blade.

detailed description

The present invention will be described in further detail below with reference to the accompanying drawings.

1-3, a bimetal band saw blade weld strength testing device, which includes a compression testing machine, a fixture 2 and a plug 4, the compression testing machine includes a base 3, a frame 1 located on the base 3, and a set on the frame 1. The lifting beam 2; the plug 4 is fixed at the bottom of the lifting beam 2, the fixture 7 is located under the plug 4, and the plug 4 is a cemented carbide plug; the compression testing machine is a commonly used equipment in mechanical property testing, which can test the object (band saw blade) Apply the test force and record the test force;

The clamp 7 is provided with a groove 6, a fastening screw hole 5 and a positioning through hole 9. The positioning through hole 9 extends along the vertical direction and is used to fix the clamp 7 on the base 3 by fastening bolts (not shown). The groove 6 is located on the side of the clamp 7 and extends along the vertical direction. The height of the groove 6 and the clamp 7 is 130 mm. The groove 6 accommodates the band saw blade 10 and the pressing block 8. A screw (not shown) can abut against the pressing block 8 to fix the band saw blade 10 in the groove 6 . Preferably, the projection of the positioning through hole 9 on the horizontal plane is a waist-shaped hole, so that when testing bandsaw blades of different widths, the position of the clamp 7 on the base 3 can be adjusted (the clamp moves along the direction of the waist-shaped hole), After adjusting in place, fix the clamp 7 by tightening bolts (not shown) to ensure that the teeth of the band saw blade are located directly under the head 4 .

The height of the pressure block 8 is the same as the height of the groove 6. The pressure block 8 can disperse the tightening force of the fastening screws and prevent the band saw blade from being deformed during the fixing process. The fastening screw holes 5 are arranged at intervals along the vertical direction. In this way, the band saw blade 10 can be fixed by a plurality of fastening screws.

During the test, cut the band saw blade 10 into small pieces of samples no higher than 130mm, and place it vertically into the groove 6 of the fixture 7 by positioning the back and bottom edges, and then push the pressing block 8 to fix the belt by tightening the screw. Saw blade 10. After the band saw blade is fixed, loosen the fastening bolts in the positioning through holes 9, and adjust the position of the clamp 7 on the base 3 so that the welding seam of the band saw blade 10 is on the striking surface of the head 4 (that is, the saw teeth of the band saw are located on the head of the head. Right below), then tighten the fastening bolts to lock the fixture, and conduct the test through the compression testing machine. Driven by the lifting beam 2, the plug 4 moves down slowly at a constant speed; when the plug 4 contacts the weld, the test force gradually increases until the tooth weld is broken; the compression tester records that the weld is broken The force F; measure the fracture length L, the thickness of the saw blade is b, and find the area of the weld S=L*b. Then the required weld strength σ=F/(L*b).

The embodiments of the present invention are described above with reference to the accompanying drawings, and the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict. The present invention is not limited to the above-mentioned specific embodiments, and the above-mentioned specific embodiments are only illustrative rather than limiting. Those of ordinary skill in the art, under the inspiration of the present invention, do not deviate from the purpose and rights of the present invention. In the case of the claimed protection scope, many forms can also be made, which all fall within the protection scope of the present invention.

Claims

A bimetal band saw blade weld strength testing device, characterized in that it comprises a compression testing machine, a clamp (7) and a plug (4), the compression testing machine comprising a base (3) and a frame located on the base (3) (1) and a lifting beam (2) arranged on the frame (1); the jack (4) is fixed on the bottom of the lifting beam (2), and the clamp (7) is located below the jack (4) ;

The fixture (7) is provided with a groove (6), a fastening screw hole (5) and a positioning through hole (9), the positioning through hole (9) extending in the vertical direction and used for passing the fastening bolt The clamp (7) is fixed on the base (3), the groove (6) is located on the side of the clamp (7) and extends along the vertical direction, and the groove (6) accommodates A band saw blade (10) and a pressure block (8) are provided, and the tightening screw in the tightening screw hole (5) abuts against the pressure block (8) so as to fix the band saw blade (10) on the in the groove (6).
A device for testing the weld seam strength of a bimetal band saw blade according to claim 1, wherein the projection of the positioning through hole (9) on the horizontal plane is a waist-shaped hole.
A device for testing the weld seam strength of a bimetal band saw blade according to claim 1, wherein the plug (4) is a cemented carbide plug (4).
The device for testing the weld seam strength of a bimetal band saw blade according to claim 1, wherein a plurality of said fastening screw holes (5) are provided at intervals along the vertical direction.
A device for testing the weld seam strength of a bimetal band saw blade according to claim 1, characterized in that the height of the pressing block (8) is the same as the height of the groove (6).
A method for testing the weld seam strength of a bimetal band saw blade, which adopts the device for testing the weld seam strength of a bimetal band saw blade according to any one of claims 1-5, and mainly comprises the following steps:

Cut the band saw blade (10) into segment samples, put them into the groove (6) of the fixture (7), and push the pressing block (8) through the tightening screw to fix the band saw blade sample;

Adjust the position of the clamp (7) on the base (3) so that the saw teeth of the band saw blade (10) are located directly under the head (4), and tighten the fastening bolts to lock the clamp (7) on the base (3);

Start the compression testing machine, the plug (4) gradually moves to the sawtooth until the sawtooth weld is broken, and the compression testing machine records the force F that breaks the weld; measure the fracture length L, and the thickness of the saw blade is b, then the weld strength σ=F /(L*b).