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A vibration tester is used to test the quality and safety of fuzes, initiating explosive devices, bullets and other ignition mechanisms (hereinafter referred to as "the product") during transportation. After a certain period of vibration, no relative movement, deformation, damage, ignition or explosion shall occur in the parts of the product.
Working principle of the vibration tester: vibration test is a periodic impact test. As shown in Figure 1, the product is fixed on an upper plate 3 of the vibration tester by an auxiliary tool. When a shaft 1 drives a cam 2 to rotate, the upper plate is lifted by the cam and rotates around a hinge. After being lifted to the highest position, the upper plate is separated from the cam, and under the action of the gravitational torque of the upper plate (including the auxiliary tool and the product), it falls on a lower plate 4 and collides with it. Due to the continuous rotation of the cam, the above process is repeated, and the product is tested with a certain impact effect.
Figure 1
I Technical requirements
1. The vibration tester shall conform to an approved unified product drawing and the requirements of this standard.
2. When the upper plate with the auxiliary tool is lifted to the highest position by the cam,
the vertical height, corresponding to the auxiliary tool center, from the lower plane of the upper plate to the upper plane of the lower plate, is taken as the falling height of the upper plate (Figure 2), and its height is generally as follows:
100±2mm when testing fuzes;
150±2mm when testing initiating explosive devices and other ignition mechanisms;
80±2mm when testing bullets.
Note: If the product has other requirements for falling height, it shall be implemented according to the requirements of the product drawing.
Figure 2
3. The cam speed is 60±1rpm.
4. The weight of the upper plate is 4.8-6.5kg; the arc radius of the protrusion shall be not greater than 35mm; the width of the upper plate is allowed to be made of no more than 3 long slats; after being repaired and maintained in use, its thickness shall not be less than 33mm, and other dimensions shall comply with the drawing.
5. The vibration tester shall be placed on the slag (coke allowed) layer in a land tank (or cement tank), and its particle size shall be screened by a sieve with upper sieve hole of 12×12mm and lower sieve hole of 8×8mm, and its thickness is 500-600 mm. It may also be placed on a cement foundation covered with oil-resistant rubber plates or ordinary rubber plates (see Figure 3). The rubber plate codes are 3001 and 3001 respectively (Ministry of Chemical Industry standard HG4-400-66). Rubber plates of other codes with similar physical performance are acceptable with the thickness of the rubber plate of 30mm. The rubber plate may also be made of no more than 3 layers of rubber plates with a total thickness of 30mm.
Figure 3
6. Check the levelness of the vertical and horizontal direction of the cam end on the upper surface of a bench with a quadrant or level meter, and the allowable deviation shall not exceed 10′.
7. Total weight of the product and the auxiliary tool or a vibration box: when testing fuzes, the total weight shall not exceed 15kg; when testing initiating explosive devices, bullets and ignition mechanisms, it shall not exceed 8kg. If the total weight of the product or the auxiliary tool is otherwise specified in the product drawing, this restriction shall not apply.
8. It is allowed to cover the protrusion of the upper plate with cowhide or other materials, which shall not be greater than 5mm in thickness.
9. When a pulley is moved by hand to rotate the cam, the upper plate shall rise smoothly, without colliding or jamming with the cam. The protrusion of the upper plate shall not be skewed after coming into contact with the arc-shaped part of the cam. A gap of no more than 18mm long is allowed to exist in the contact part, but shall not be greater than 0.15mm wide.
10. The metal parts of the vibration tester shall be free of defects such as cracks, interlayers and shrinkage cavities.
11. The upper and lower plates of vibration tester shall not have cracks, spots, scars, caving or oil immersion at the impact position.
I Technical requirements
II Acceptance rules
III Method of use
IV Package and marking
