Pre-pressing pressure applying device for hardness tester

Abstract

The utility model provides a pre-pressing pressure applying device for a hardness tester. The pre-pressing pressure applying device comprises a weight sleeve, a weight cover, a weight rod, a weight, a weight rod nut and a weight cushion, a vertical through hole is formed in the center of the weight sleeve, the weight cover covers the top end of the weight sleeve, and a limiting hole is formed in the center of the weight cover; the top end of the weight rod penetrates through the limiting hole, the weight rod nut is in threaded fit with the lower area of the top end of the weight rod, the diameter of the weight rod nut is larger than the diameter of the limiting hole so as to limit the vertical maximum displacement of the weight rod, and the weight buffer pad is arranged between the limiting hole and the weight rod nut; the main body part of the weight rod penetrates through the vertical through hole of the weight sleeve, and a pressure applying head is formed at the bottom end of the weight rod; the top end of the weight rod serves as an installation position for installing the weight, and the weight is arranged at the top end of the weight rod through the center hole to apply pressure. The prepressing pressure applying device for the hardness tester has the advantage of high prepressing load control flexibility.

Description

Technical Field

[0001] The utility model relates to the technical field of measuring instruments, and specifically, to a preloading pressure applying device for a hardness tester. Background Art

[0002] In the tobacco industry, products such as ordinary cigarettes, filter rods, bursting beads, cigars, etc. all need to be subjected to hardness testing. Therefore, a hardness tester is one of the most commonly used testing devices.

[0003] According to the provisions of the Chinese tobacco industry standard YC / T28.6 - 1996: The definition of hardness is: the percentage of the diameter of the specimen after radial compression within a certain time to the diameter of the specimen before compression. The testing instrument should be a device for point - pressing the specimen radially, with a pressing load of 2.94 ± 0.01 N, a indenter diameter of 12 ± 0.01 mm, a compression time of 15 ± 1 s, and a pressing speed of 0.55 ± 0.05 mm / s.

[0004] Therefore, in a hardness tester, the pressure applying device for applying pressure is one of the very critical components.

[0005] Currently, the more widely used pressure applying device is mainly the air - floating shaft product developed by Oumeilihua, which has the characteristics of small friction and high pressing accuracy.

[0006] However, the flexibility of its device is not high, and the pressing value cannot be adjusted flexibly, resulting in limitations in application. Subsequently, many products have been improved and developed based on it, but none of them are satisfactory.

[0007] In order to solve the above - mentioned existing problems, people have been seeking an ideal technical solution. Content of the Utility Model

[0008] The purpose of the utility model is to aim at the deficiencies of the prior art, and thus provide a preloading pressure applying device for a hardness tester with high flexibility in preloading load control.

[0009] In order to achieve the above purpose, the technical solution adopted by the utility model is: a preloading pressure applying device for a hardness tester, including a weight sleeve, a weight cover, a weight rod, weights, a weight rod nut, and a weight buffer pad;

[0010] A vertical perforation is provided at the center of the weight sleeve, the weight cover seals the top of the weight sleeve, and a limit hole is provided at the center of the weight cover;

[0011] The top of the weight rod passes through the limit hole, the weight rod nut is in threaded fit with the lower region of the top of the weight rod, the diameter of the weight rod nut is greater than the diameter of the limit hole to limit the maximum vertical displacement of the weight rod, and the weight buffer pad is arranged between the limit hole and the weight rod nut;

[0012] The main body part of the weight rod passes through the vertical perforation of the weight sleeve, and the bottom end of the weight rod forms a pressing head.

[0013] The top end of the weight rod serves as an installation position for installing weights, and the weights are seated on the top end of the weight rod through the central hole for pressing.

[0014] Based on the above, the pressing head at the bottom end of the weight rod is a detachable pressing head. An installation hole is provided at the bottom end of the weight rod, the top end of the pressing head is inserted into the installation hole, and the pressing head is coaxial with the weight rod.

[0015] Based on the above, the end area of the pressing head is larger than the cross-sectional area at the maximum diameter of the weight rod.

[0016] Based on the above, a weight rod anti-rotation block is also assembled at the top end of the weight rod. The cross-section of the top end of the weight rod is set to a non-circular shape. The weight rod anti-rotation block has a constraint hole with a matching cross-section. An anti-rotation notch is provided at the eccentric position of the weight anti-rotation block. A corresponding positioning hole is provided on the weight cover, and a guide shaft is fixed in the positioning hole. The guide shaft is in sliding fit with the anti-rotation notch, and anti-rotation constraint is achieved by vertically passing the guide shaft through the anti-rotation notch and the positioning hole.

[0017] Based on the above, the pre-pressing load of the pre-pressing head of the weight rod is 0.1 N.

[0018] Based on the above, the bottom end of the pre-pressing head is a circular plane with a diameter of 12 - 15 mm.

[0019] Based on the above, a steel column counterweight block is provided on the weight rod.

[0020] Based on the above, the overall full-pressing load of the pre-pressing device for the hardness tester is 2.94 N.

[0021] The present utility model has substantial features and progress compared with the prior art. Specifically, by adopting the structural form of a longitudinally separable weight sleeve and a weight rod, in the general state, the weight rod presses on the weight sleeve to maintain self-stability. When pre-pressing is required, the entire device moves downward, and the weight rod pre-presses on the working surface. As the weight sleeve continues to move downward, the weight sleeve and the weight rod gradually separate, and the weight rod gradually loses longitudinal support. Only the weight of the weight rod assembly and the weights remain on the working surface, so that the pre-pressing force can accurately act on the working surface, ensuring the pre-pressing accuracy.

[0022] The weight rod of the set hardness pre-pressing device can reach a minimum pre-pressing load of 0.1 N without counterweight, and there is no friction influence from other mechanisms during the movement process, so that the adjustable range of pre-pressing is wide, the flexibility is high, and the accuracy is high. It can be used for pressure test experiments with a relatively high accuracy of set pressure values. Description of the Drawings

[0023] Figure 1 It is a schematic diagram of the overall structure of the pre - pressing device for a hardness tester in the present utility model.

[0024] Figure 2 It is a cross - sectional view of the application state of the pre - pressing device for a hardness tester in the present utility model.

[0025] In the figure: 1. Weight sleeve; 2. Weight cover; 3. Weight rod; 4. Weight; 5. Weight rod nut; 6. Weight buffer pad; 7. Pressing head; 8. Anti - rotation block for weight rod; 9. Guide shaft. Detailed Description of the Preferred Embodiments

[0026] Next, through the detailed description of the embodiments, the technical solutions of the present utility model will be further described in detail.

[0027] As Figure 1 and Figure 2 shown, a pre - pressing device for a hardness tester includes a weight sleeve 1, a weight cover 2, a weight rod 3, a weight 4, a weight rod nut 5, and a weight buffer pad 6.

[0028] A vertical perforation is provided at the center of the weight sleeve 1. The weight cover 2 covers the top end of the weight sleeve 1, and a limiting hole is provided at the center of the weight cover 2.

[0029] The top end of the weight rod 3 passes through the limiting hole. The weight rod nut 5 is in threaded cooperation with the lower region of the top end of the weight rod 3. The diameter of the weight rod nut 5 is larger than the diameter of the limiting hole to limit the maximum vertical displacement of the weight rod 3. The weight buffer pad 6 is provided between the limiting hole and the weight rod nut 5 to protect the weight rod 3 from hard - contact collision with the weight cover 2 during vertical movement.

[0030] The main part of the weight rod 3 passes through the vertical perforation of the weight sleeve 1. The bottom end of the weight rod 3 forms a pressing head 7. In this embodiment, the pressing head 7 at the bottom end of the weight rod 3 is a detachable pressing head. An installation hole is provided at the bottom end of the weight rod 3, and the top end of the pressing head 7 is inserted into the installation hole. The pressing head 7 is coaxial with the weight rod 3, and the end area of the pressing head 7 is larger than the cross - sectional area at the largest diameter of the weight rod, specifically a circular plane with a diameter of 12 - 15 mm.

[0031] The top end of the weight rod 3 serves as an installation position for the weight 4, and the weight 4 is seated on the top end of the weight rod 3 through the central hole for pressing.

[0032] A weight rod anti-rotation block 8 is also assembled at the top of the weight rod 3. The cross-section of the top of the weight rod 3 is set to a non-circular shape. The weight rod anti-rotation block 8 has a constraint hole with a matching cross-section. An anti-rotation notch is provided at the eccentric position of the weight anti-rotation block 8. Corresponding positioning holes are provided on the weight cover 2. Anti-rotation constraint is achieved by vertically passing a guide shaft 9 through the anti-rotation notch and the positioning hole. Its main function is to prevent the weight rod from rotating during testing and improve stability.

[0033] Among them, the guide shaft 9 is fixed in the positioning hole, and the guide shaft 9 is in sliding fit with the anti-rotation notch.

[0034] The preloading pressure load of the preloading head of the weight rod 3 is 0.1 N, and the full-pressure loading load of the overall preloading device for the hardness tester is 2.94 N.

[0035] To ensure the gravity balance of the entire device, steel column counterweight blocks are provided on the weight rod.

[0036] Description of the working principle:

[0037] During the detection process, the outer linear motor holds the upper edge of the weight sleeve and drives the entire device to move vertically downward. When the preloading device fully acts on the sample to be measured, the motor stops, and the sensor value is recorded. After 1 s, the motor continues to move vertically downward until the preloading device fully acts on the sample to be measured, and the sensor value is recorded after 15 s.

[0038] If it is necessary to remove the preloading device, only need to rotate out the weight rod nut and the weight rod anti-rotation block fixed above the weight rod.

[0039] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: still can modify the specific implementation manners of the present invention or perform equivalent replacements for some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. A preloading pressure application device for a hardness tester, characterized in that: It includes a weight sleeve, a weight cover, a weight rod, weights, a weight rod nut, and a weight buffer pad; A vertical perforation is provided at the center of the weight sleeve, the weight cover seals the top end of the weight sleeve, and a limiting hole is provided at the center of the weight cover; The top end of the weight rod passes through the limiting hole, the weight rod nut is in threaded fit with the lower region of the top end of the weight rod, the diameter of the weight rod nut is larger than the diameter of the limiting hole to limit the maximum vertical displacement of the weight rod, and the weight buffer pad is arranged between the limiting hole and the weight rod nut; The main body part of the weight rod passes through the vertical perforation of the weight sleeve, and the bottom end of the weight rod forms a pressing head; The top end of the weight rod serves as an installation position for installing weights, and the weights are seated on the top end of the weight rod through the central hole for pressing.

2. The preloading pressure application device for a hardness tester according to claim 1, characterized in that: The pressing head at the bottom end of the weight rod is a detachable pressing head, an installation hole is provided at the bottom end of the weight rod, the top end of the pressing head is inserted into the installation hole, and the pressing head is coaxial with the weight rod.

3. The preloading pressure application device for a hardness tester according to claim 1 or 2, characterized in that: The end area of the pressing head is larger than the cross-sectional area at the maximum diameter of the weight rod.

4. The preloading pressure application device for the hardness tester according to claim 3, characterized in that: A weight rod anti-rotation block is also assembled at the top end of the weight rod. The cross-section of the top end of the weight rod is set to be non-circular. The weight rod anti-rotation block has a constraint hole with a matching cross-section. An anti-rotation notch is provided at the eccentric position of the weight rod anti-rotation block. A corresponding positioning hole is provided on the weight cover, and a guide shaft is fixed in the positioning hole. The guide shaft is in sliding fit with the anti-rotation notch, and anti-rotation constraint is achieved by the guide shaft vertically passing through the anti-rotation notch and the positioning hole.

5. The preloading pressure application device for a hardness tester according to claim 4, characterized in that: The pre-pressing load of the pre-pressing head of the weight rod is 0.1 N.

6. The preloading pressure application device for a hardness tester according to claim 5, characterized in that: The bottom end of the pre-pressing head is a circular plane with a diameter of 12 - 15 mm.

7. The preloading pressure application device for a hardness tester according to claim 6, characterized in that: A steel column counterweight block is arranged on the weight rod.

8. The preloading pressure application device for a hardness tester according to claim 7, characterized in that: The overall full-pressing load of the pre-pressing device for the hardness tester is 2.94 N.

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