Anti-drop-hammer Marshall compaction test apparatus

Abstract

The utility model relates to the technical field of road engineering, in particular to an anti-drop-hammer Marshall compaction test apparatus. The anti-drop hammer Marshall compaction apparatus comprises an apparatus body, a test mold base, a driving hammer guide rail and a driving assembly. A cavity is formed in the equipment body, the test mold base is fixed at the bottom of the cavity, and the test mold base is used for fixing a Marshall test piece. The upper end of the driving hammer guide rail is fixed to the top of the cavity, the lower end of the driving hammer guide rail is provided with a compaction piece, the top of the test mold base is provided with a limiting groove, and the compaction piece is installed in the limiting groove. The driving hammer guide rail is slidably connected with a driving hammer, and the driving assembly is arranged at the top of the cavity and connected with the driving hammer. The anti-drop hammer Marshall compaction apparatus provided by the utility model can ensure that the driving hammer guide rail does not move in the compaction process of a Marshall test piece, and effectively reduces the situation that the compaction times of the Marshall test piece do not reach the standard, thereby ensuring the molding stability of the Marshall test piece and effectively ensuring the data accuracy of the test piece.

Description

Technical Field

[0001] The utility model relates to the technical field of road engineering, in particular to an anti-drop hammer Marshall compactor. Background Art

[0002] The Marshall Compactor is a specialized instrument for compacting asphalt mixture specimens during the Marshall stability test. It features a compact size, easy operation, reliable operation, and automatic sample compaction. Based on the impact principle of physics, the Marshall Compactor utilizes a motor drive, chain transmission, and the free-fall of a standard hammer to simulate the compaction of asphalt mixtures by vehicles during actual road construction, achieving compaction and shaping of asphalt mixture specimens.

[0003] However, when the Marshall compactor is used for a long time, the hammer guide rail is easy to move away from its original position and move back and forth, causing the hammer to drop in the Marshall compactor, affecting the sample forming quality. Utility Model Content

[0004] In order to solve the defects of the existing technology, the utility model provides an anti-drop hammer Marshall compactor, which can ensure that the hammer guide rail will not move during the compaction process of the Marshall specimen, and the hammering action of the hammer on the compacted part can stably act on the Marshall specimen, effectively reducing the situation where the number of compaction times of the Marshall specimen does not meet the standard, thereby ensuring the molding stability of the Marshall specimen and effectively ensuring the data accuracy of the sample.

[0005] In order to solve the above technical problems, the utility model provides an anti-drop hammer Marshall compaction instrument, comprising:

[0006] The device body has a cavity formed therein;

[0007] A test mold base is fixed to the bottom of the cavity, and the test mold base is used to fix the Marshall test piece;

[0008] A hammer guide rail, wherein the upper end of the hammer guide rail is fixed to the top of the cavity, the lower end of the hammer guide rail is provided with a compacting member, the top of the test mold base is provided with a limiting groove, the compacting member is installed in the limiting groove, the limiting groove is used to limit and fix the compacting member, and the hammer guide rail is slidably connected to the hammer;

[0009] A driving assembly is arranged at the top of the cavity, the driving assembly is connected to the hammer, and the driving assembly is used to drive the hammer to move up and down along the hammer guide rail.

[0010] Wherein, the limiting groove is provided with a buckle, and the compacting member is provided with a snap-fitting groove, and the buckle is snap-fitted with the snap-fitting groove.

[0011] The test mold base is made of metal material, and a sample cavity is formed on the test mold base. The sample cavity is used to accommodate the Marshall test piece, and the inner wall surface of the sample cavity is sprayed with a lubricating coating.

[0012] Wherein, the limiting groove is provided with a test mold cover, the compacting member is pressed tightly against the upper side of the test mold cover, and the sample cavity is located on the lower side of the test mold cover.

[0013] Wherein, the surface of the hammer guide rail is coated with an anti-rust coating.

[0014] The hammer is slidably sleeved on the hammer guide rail, a connecting block is formed on the side wall of the hammer facing the drive assembly, the hammer is connected to the drive assembly through the connecting block, the hammer is formed by forging, and the bottom surface of the hammer is a plane.

[0015] Wherein, the driving component includes:

[0016] A driving motor is fixedly mounted on the top of the cavity;

[0017] A transmission member, one end of which is connected to the drive motor, and the other end of which is connected to the hammer.

[0018] Wherein, a fixed support is formed on the bottom wall surface of the cavity, and the trial mold base is arranged on the fixed support.

[0019] Wherein, the inner wall surface of the cavity is provided with a sound-absorbing layer, and the sound-absorbing layer is filled with a sound-absorbing material, and the sound-absorbing material is sound-absorbing cotton.

[0020] Among them, also include:

[0021] The sliding door is rotatably connected to the outer wall of the equipment body. The sound-absorbing layer is provided inside the sliding door. The equipment body is formed with a sealing surface. The sliding door is suitable for abutting against the sealing surface. The sealing surface is provided with a sound-absorbing member.

[0022] The implementation of this utility model has the following beneficial effects:

[0023] The anti-drop hammer Marshall compaction instrument provided by the present invention utilizes a drive assembly to drive a hammer to move up and down along a hammer guide rail, so that the hammer can compact a Marshall specimen in a test mold base, completing the compaction and molding of the Marshall specimen. During the compaction of the Marshall specimen by the hammer, a compacting member at the lower end of the hammer guide rail is mounted in a limit slot. The limit slot can limit the displacement of the compacting member, thereby preventing the compacting member from deviating from its original position, thereby securing the lower end of the hammer guide rail in the limit slot.

[0024] Furthermore, when the upper end of the hammer guide rail is fixed to the top of the cavity and the lower end of the hammer guide rail is fixed to the limit slot, it can effectively ensure that the hammer guide rail is fixed in the internal cavity of the equipment body, ensuring that the hammer guide rail will not move during the compaction process of the Marshall specimen. The hammering action of the hammer on the compacted part can stably act on the Marshall specimen, effectively reducing the situation where the number of compaction times of the Marshall specimen does not meet the standard, thereby ensuring the forming stability of the Marshall specimen and effectively ensuring the data accuracy of the sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the anti-drop hammer Marshall compactor of the present invention. DETAILED DESCRIPTION

[0026] To make the objectives, technical solutions, and advantages of the present invention more clearly apparent, the present invention will be further described in detail below with reference to the accompanying drawings. It is hereby stated that any directional terms such as "up," "down," "left," "right," "front," "back," "inside," and "outside" that appear or will appear in this document are based solely on the accompanying drawings and are not intended to limit the present invention.

[0027] The anti-drop hammer Marshall compactor provided by the utility model can ensure that the hammer guide rail 3 will not move during the compaction process of the Marshall specimen, and the hammering action of the hammer 4 on the compaction piece 31 can stably act on the Marshall specimen, effectively reducing the situation where the number of compaction times of the Marshall specimen does not meet the standard, thereby ensuring the molding stability of the Marshall specimen and effectively ensuring the data accuracy of the sample.

[0028] In a specific embodiment of the present invention, Figure 1 As shown, the anti-drop hammer Marshall compactor includes an apparatus body 1, a test mold base 2, a hammer guide rail 3, and a drive assembly 5. A cavity 11 is formed inside the apparatus body 1, and the test mold base 2 is fixed to the bottom of the cavity 11. The test mold base 2 is used to fix the Marshall test piece. The upper end of the hammer guide rail 3 is fixed to the top of the cavity 11, and a compacting member 31 is provided at the lower end of the hammer guide rail 3. A limiting groove 21 is provided at the top of the test mold base 2, and the compacting member 31 is installed in the limiting groove 21. The limiting groove 21 is used to limit and fix the compacting member 31. The hammer guide rail 3 is slidably connected to the hammer 4. The drive assembly 5 is provided at the top of the cavity 11 and is connected to the hammer 4. The drive assembly 5 is used to drive the hammer 4 to move up and down along the hammer guide rail 3.

[0029] The anti-drop hammer Marshall compactor provided by the present invention utilizes a drive assembly 5 to drive a hammer 4 to move up and down along a hammer guide rail 3, so that the hammer 4 can compact the Marshall specimen in the test mold base 2, completing the compaction and molding of the Marshall specimen. During the compaction of the Marshall specimen by the hammer 4, a compacting member 31 at the lower end of the hammer guide rail 3 is mounted in a limiting groove 21. The limiting groove 21 can limit the displacement of the compacting member 31, thereby preventing the compacting member 31 from shifting from its original position, thereby securing the lower end of the hammer guide rail 3 in the limiting groove 21.

[0030] Furthermore, when the upper end of the hammer guide rail 3 is fixed to the top of the cavity 11 and the lower end of the hammer guide rail 3 is fixed to the limit groove 21, it can effectively ensure that the hammer guide rail 3 is fixed in the cavity 11 inside the equipment body 1, ensuring that the hammer guide rail 3 will not move during the compaction process of the Marshall specimen, and the hammering action of the hammer 4 on the compaction piece 31 can stably act on the Marshall specimen, effectively reducing the situation where the number of compaction times of the Marshall specimen does not meet the standard, thereby ensuring the molding stability of the Marshall specimen and effectively ensuring the data accuracy of the sample.

[0031] The hammer guide rail 3 can be made of a metal material such as cast iron or steel, which effectively ensures that the hammer guide rail 3 has high strength and hardness, ensuring that the hammer 4 does not wobble or deform when the hammer 4 moves up and down on the hammer guide rail 3, thereby ensuring the stability of the up and down movement of the hammer 4. The hammer guide rail 3 is connected to the inner wall surface of the top of the cavity 11 with bolts to improve the installation stability of the top of the hammer guide rail 3.

[0032] It should be noted that the shape of the compacting member 31 corresponds to and matches the shape of the limiting groove 21. Preferably, the limiting groove 21 is a circular countersunk hole, and the compacting member 31 is a truncated cone structure. A connecting boss is formed on the side of the compacting member 31 facing the hammer guide rail 3. The connecting boss is formed with a socket. The lower end of the hammer guide rail 3 is inserted into the socket and fixed by a fastener to connect the compacting member 31 to the lower end of the hammer guide rail 3. Of course, in other embodiments, the compacting member 31 can also be integrally formed with the hammer guide rail 3 to reduce the number of parts in the anti-drop hammer Marshall compaction instrument.

[0033] In order to ensure that the compacting member 31 is fixed in the limiting groove 21, as shown in FIG. Figure 1 As shown, the limiting groove 21 is provided with a buckle 211, and the compacting piece 31 is provided with a snap-fitting groove. The buckle 211 is snap-fitted with the snap-fitting groove. After the compacting piece 31 is inserted into the limiting groove 21, the buckle 211 can be snapped into the snap-fitting groove. The compacting piece 31 is fixed by the buckle 211 to fix the lower end of the hammer guide rail 3, thereby ensuring that the hammer guide rail 3 does not move forward and backward during long-term use, thereby ensuring that the hammer 4 can stably hammer the compacting piece 31 and ensure the molding quality of the Marshall specimen.

[0034] It should be noted that a pressure spring is provided on the side of the buckle 211 facing the side wall of the limiting groove 21. The buckle 211 is connected to the limiting groove 21 via the pressure spring. This allows the buckle 211 to utilize the elastic force of the pressure spring to increase the fixing force of the buckle 211 on the compacting member 31 while ensuring that the buckle 211 is easy to remove. When the Marshall specimen needs to be removed from the test mold base 2, the buckle 211 can be disconnected from the compacting member 31 and the compacting member 31 can be removed from the limiting groove 21 to remove the Marshall specimen. Of course, the buckle 211 itself can also have a certain degree of elasticity. When the compacting member 31 is installed in the limiting groove 21, the buckle 211 undergoes elastic deformation and engages with the compacting member 31.

[0035] Among them, such as Figure 1 As shown, the test mold base 2 is made of metal and defines a specimen cavity 22 for accommodating the Marshall specimen. Preferably, the test mold base 2 is cast iron to ensure that the test mold base 2 can withstand the hammering force applied by the hammer 4 during the compaction process, thereby preventing deformation of the test mold base 2 that would affect the formation of the Marshall specimen.

[0036] However, due to the high friction between the Marshall specimen and the sidewalls of the test mold base 2, it is difficult to place the unformed Marshall specimen into the test mold base 2 and to remove the formed Marshall specimen from the test mold base 2. In this embodiment, to enhance the smoothness of the Marshall specimen during insertion and removal, the inner wall of the specimen cavity 22 is spray-coated with a lubricating coating. The lubricating coating increases the smoothness of the inner wall of the test mold base 2, ensuring that the Marshall specimen can be inserted and removed more easily.

[0037] Preferably, the lubricating coating is a nano coating with a thickness of 0.8 mm. The nano coating increases the smoothness of the test mold base 2, ensuring that the Marshall specimen can be conveniently removed from the test mold base 2. At the same time, the anti-adhesion properties of the nano coating are utilized to effectively prevent sample residues from adhering to the inner wall surface of the test mold base 2.

[0038] Further, if Figure 1 As shown, the limiting groove 21 is provided with a test mold cover 23, the compacting piece 31 is pressed against the upper side of the test mold cover 23, and the sample cavity 22 is located on the lower side of the test mold cover 23, so that the test mold cover 23 is used to cover the Marshall specimen in the sample cavity 22, and the hammering force exerted on the compacting piece 31 is transmitted to the Marshall specimen through the test mold cover 23, so that the Marshall specimen can be subjected to uniform pressure, ensuring that the surface of the Marshall specimen after molding is smooth and the shape is regular, and effectively improving the molding quality of the Marshall specimen.

[0039] Among them, the surface of the hammer guide rail 3 is coated with an anti-rust coating, and the anti-rust coating is used to protect the surface of the hammer guide rail 3 to prevent the hammer guide rail 3 from rusting due to moisture, ensuring that the hammer 4 and the hammer guide rail 3 can slide relative to each other, and effectively ensuring the hammering effect of the hammer 4 on the compacting part 31.

[0040] Specifically, the anti-rust coating is preferably a nano-ceramic coating. While the nano-ceramic coating ensures the anti-rust effect, the nano-coating improves the lubricity of the surface of the hammer guide rail 3, reduces the friction of the hammer 4 when moving on the hammer guide rail 3, and thus reduces energy loss.

[0041] Among them, such as Figure 1 As shown, the hammer 4 is slidably mounted on the hammer guide rail 3. A connecting block is formed on the side wall of the hammer 4 facing the drive assembly 5. The hammer 4 is connected to the drive assembly 5 via the connecting block to ensure that the drive assembly 5 can drive the hammer 4 to move up and down along the hammer guide rail 3, facilitating the application of hammering force to the Marshall specimen through the drive assembly 5. The hammer 4 is forged, and the bottom surface of the hammer 4 is flat. Specifically, the hammer 4 is preferably forged into a cylindrical shape from metal to reduce internal defects and improve its impact resistance. The hammer 4 is then processed using a CNC cutting process to form a flat bottom surface. This prevents uneven force applied by the hammer 4 when striking the compaction piece 31, ensuring uniform pressure on the compaction piece 31 and further ensuring the quality of the Marshall specimen.

[0042] In addition, since the bottom surface of the hammer 4 is a plane, when the top surface of the compacting piece 31 is also a plane, the contact surface between the hammer 4 and the compacting piece 31 is flat. When the hammer 4 applies uniform force to the compacting piece 31, the hammer 4 will not produce additional impact rebound when hitting the compacting piece 31, thereby reducing the energy lost by the hammer 4 during impact rebound and further reducing energy loss.

[0043] Exemplarily, the connecting block is a square structure, and the connecting block can be integrally formed with the hammer 4 to reduce the number of parts; the connecting block can also be fixed to the hammer 4 by fasteners such as bolts to facilitate the connection between the hammer 4 and the drive assembly 5.

[0044] Among them, such as Figure 1 As shown, the drive assembly 5 includes a drive motor 51 and a transmission member 52. The drive motor 51 is fixedly mounted at the top of the cavity 11. One end of the transmission member 52 is connected to the drive motor 51, and the other end of the transmission member 52 is connected to the hammer 4. Preferably, the transmission member 52 is a transmission group consisting of a gear and a transmission chain. The gear is connected to the drive shaft of the drive motor 51, and the transmission chain is engaged with the gear. The portion of the transmission chain near the hammer 4 is connected to the connecting block of the hammer 4. The drive motor 51 drives the gear to rotate, drives the transmission chain to move up and down, and thus drives the hammer 4 to move up and down, completing the hammering of the hammer 4 on the compacting member 31.

[0045] In this embodiment, the drive motor 51 is electrically connected to the external control component. The drive motor 51 is preferably a permanent magnet synchronous brushless motor. This motor delivers greater torque, ensuring that the hammer 4 can exert sufficient impact force, effectively ensuring that each formed Marshall specimen meets the required compaction work, further ensuring test accuracy. Furthermore, the more stable output rate of the permanent magnet synchronous brushless motor effectively prevents the hammer 4 from operating for extended periods, which would increase the motor's internal resistance and prevent burnout of the drive motor 51. Furthermore, the permanent magnet synchronous brushless motor generates less noise, effectively reducing operating noise during operation.

[0046] Among them, such as Figure 1 As shown, a fixed support 12 is formed on the bottom wall of the cavity 11, and the test mold base 2 is disposed on the fixed support 12. The fixed support 12 provides a stable support effect for the test mold base 2 and lowers the overall center of gravity of the anti-drop weight Marshall compaction instrument to the fixed support 12, effectively ensuring the stability of the equipment operation. Preferably, the fixed support 12 is made of cement bricks.

[0047] Specifically, the trial mold base 2 is fixed to the fixed support 12 by fasteners such as bolts.

[0048] In this embodiment, the outer shell of the equipment body 1 is made of stainless steel to facilitate cleaning of the inner cavity of the equipment body 1 and prevent asphalt concrete from adhering to the inner wall surface of the cavity 11.

[0049] When the hammer 4 strikes the compacting member 31, a loud hammering sound is emitted, causing the Marshall compactor to generate a relatively loud noise. To reduce the noise of the Marshall compactor, in this embodiment, a sound-absorbing layer 13 is provided on the inner wall of the cavity 11. The sound-absorbing layer 13 is filled with a sound-absorbing material, which is sound-absorbing cotton. The sound-absorbing cotton is used to block the noise generated by the hammer 4, reducing the volume of the noise transmitted to the outside of the device body 1, thereby reducing the noise transmitted to the external environment during the operation of the Marshall compactor, thereby achieving a noise reduction effect.

[0050] In this embodiment, a thermal insulation layer is further provided on the side of the sound-absorbing layer 13 facing the cavity 11. The thermal insulation layer is filled with thermal insulation material, which is glass fiber material. The thermal insulation layer is utilized to reduce the temperature difference in the cavity 11, thereby avoiding thermal stress inside the Marshall specimen and affecting the physical properties of the specimen.

[0051] Furthermore, to further ensure the silencing effect of the anti-drop hammer Marshall compactor, the anti-drop hammer Marshall compactor also includes a sliding door, a sound-absorbing layer 13 is provided inside the sliding door, the sliding door is rotatably connected to the outer wall surface of the device body 1, the device body 1 is formed with a sealing surface, the sliding door is suitable for abutting the sealing surface, and the sealing surface is provided with a sound-absorbing member. When the sliding door is closed on the device body 1, the sound-absorbing layer 13 in the sliding door and the sound-absorbing member at the sealing surface can be used to further block the compaction noise from being transmitted outward, further enhancing the noise reduction effect of the Marshall compactor.

[0052] Preferably, the sound-absorbing member is a double-layer rubber door strip.

[0053] The following combination Figure 1 Explain the working principle of the anti-drop hammer Marshall compactor:

[0054] The test mold base 2, equipped with the test mold cover 23 and the buckle 211, is assembled to the fixed support 12. The compacting member 31 is fixed to the lower end of the hammer guide rail 3. The hammer 4 is placed on the hammer guide rail 3, and then the upper end of the hammer guide rail 3 is fixed to the top of the cavity 11. After the upper end of the hammer guide rail 3 is fixed, the drive motor 51 is fixed to the top of the cavity 11, and the gears and transmission chain are meshed. The transmission chain is then connected to the hammer 4, completing the assembly of the anti-drop hammer Marshall compactor.

[0055] When assembling the Marshall specimen, the compacting member 31 is manually lifted, lifting the lower end of the hammer guide rail 3 from the retaining groove 21 to place the Marshall specimen into the test mold base 2. The compacting member 31 is then manually placed into the retaining groove 21. The buckle 211, under the elastic force of the pressure spring, secures the compacting member 31, thereby securing the lower end of the hammer guide rail 3. The Marshall specimen is now assembled. After closing the sliding door, the drive motor 51 is activated to begin the Marshall specimen compaction test.

[0056] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A drop-weight Marshall compactor, characterized in that: include: The device body has a cavity formed therein; A test mold base is fixed to the bottom of the cavity, and the test mold base is used to fix the Marshall test piece; A hammer guide rail, wherein the upper end of the hammer guide rail is fixed to the top of the cavity, the lower end of the hammer guide rail is provided with a compacting member, the top of the test mold base is provided with a limiting groove, the compacting member is installed in the limiting groove, the limiting groove is used to limit and fix the compacting member, and the hammer guide rail is slidably connected to the hammer; A driving assembly is arranged at the top of the cavity, the driving assembly is connected to the hammer, and the driving assembly is used to drive the hammer to move up and down along the hammer guide rail.

2. The anti-drop hammer Marshall compactor according to claim 1, characterized in that: The limiting groove is provided with a buckle, and the compacting piece is provided with a clamping groove, and the buckle is clamped and matched with the clamping groove.

3. The anti-drop hammer Marshall compactor according to claim 1, characterized in that: The test mold base is made of metal material and is formed with a sample cavity for accommodating the Marshall test piece. The inner wall surface of the sample cavity is sprayed with a lubricating coating.

4. The anti-drop hammer Marshall compactor according to claim 3, characterized in that: The limiting groove is provided with a test mold cover, the compacting member is pressed tightly against the upper side of the test mold cover, and the sample cavity is located at the lower side of the test mold cover.

5. The anti-drop hammer Marshall compactor according to claim 1, characterized in that: The surface of the hammer guide rail is coated with an anti-rust coating.

6. The anti-drop hammer Marshall compactor according to claim 5, characterized in that: The hammer is slidably sleeved on the hammer guide rail, and a connecting block is formed on the side wall of the hammer facing the drive assembly. The hammer is connected to the drive assembly through the connecting block. The hammer is formed by forging, and the bottom surface of the hammer is a plane.

7. The anti-drop hammer Marshall compactor according to claim 1, characterized in that: The drive assembly includes: A driving motor is fixedly mounted on the top of the cavity; A transmission member, one end of which is connected to the drive motor, and the other end of which is connected to the hammer.

8. The anti-drop hammer Marshall compactor according to claim 1, characterized in that: A fixed support is formed on the bottom wall surface of the cavity, and the trial mold base is arranged on the fixed support.

9. The anti-drop hammer Marshall compactor according to claim 1, characterized in that: The inner wall surface of the cavity is provided with a sound-absorbing layer, and the sound-absorbing layer is filled with a sound-absorbing material, and the sound-absorbing material is sound-absorbing cotton.

10. The anti-drop hammer Marshall compactor according to claim 9, characterized in that: Also includes: The sliding door is rotatably connected to the outer wall of the equipment body. The sound-absorbing layer is provided inside the sliding door. The equipment body is formed with a sealing surface. The sliding door is suitable for abutting against the sealing surface. The sealing surface is provided with a sound-absorbing member.

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