A device and method for grinding the end face of a hopkinson pressure bar

Abstract

The application discloses a kind of end face grinding device and grinding method of Hopkinson pressure bar, grinding device includes grinder, grinder has the main shaft being arranged along horizontal direction, one end of main shaft is provided with grinding head, the other end is connected with the driving component for driving main shaft rotation, the end of grinding head away from driving component has the grinding surface being arranged perpendicularly with main shaft;It also includes clamping mechanism and feeding mechanism, clamping mechanism is provided with the clamping hole being arranged in parallel with main shaft through, for transversely fixed to be ground rod;Feeding mechanism includes the material containing bin for containing grinding agent and the material collecting bin for collecting grinding agent, material containing bin is located above grinding head, and it has the material dropping hole being arranged towards grinding surface;Material collecting bin is located directly below grinding head, and it has the collecting port being arranged towards grinding head.The end face grinding device and grinding method of the application all have the advantages such as structural design ingenious, can guarantee that sufficient grinding agent acts on grinding surface, be favorable for reducing test cost etc..

Description

Technical Field

[0001] This invention relates to the field of grinding technology, and in particular to a grinding device and method for the end face of a Hopkinson pressure bar. Background Technology

[0002] A Hopkinson bar is a physical performance testing instrument used in the fields of mechanics, engineering and technology, materials science, and mechanical engineering.

[0003] The split Hopkinson bar test technique is a primary experimental method for studying the mechanical properties of materials under medium to high strain rates. Its core idea is that the stress wave propagating in the test bar simultaneously performs the functions of loading and testing. Based on the information from the propagation of the stress wave in the bar, the stress-displacement-time relationship between the bar and the specimen end face is solved, thereby obtaining the stress-strain relationship of the specimen.

[0004] The relevant dynamic compression test places high demands on the flatness, parallelism, and perpendicularity of the end faces of the incident and transmission rods in contact with the specimen. During the test, the rod ends are subjected to axial impact; uneven local stress on the rod end faces can lead to pitting, compromising flatness and parallelism. Over time, severe damage to the rod end faces significantly impacts experimental accuracy, usually requiring replacement. However, Hopkinson pressure bars are expensive, and frequent replacements greatly increase teaching costs. Grinding the rod end faces can restore their flatness and parallelism, meeting the needs of teaching experiments. Since grinding requires the use of abrasive, it is usually performed on a horizontal platform. However, the Hopkinson pressure bars have a large length-to-diameter ratio, making vertical placement impossible. Furthermore, when placed horizontally for grinding, the abrasive is lost due to gravity, failing to ensure sufficient abrasive is applied to the grinding surface. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is: how to provide an end face grinding device and grinding method for a Hopkinson pressure bar with an ingenious structural design that can ensure that a sufficient amount of abrasive is applied to the grinding surface.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A kind of end face grinding device of Hopkinson pressure bar, it is characterized in that, including grinder, the grinder has the main shaft being arranged along horizontal direction, one end of the main shaft is provided with grinding head, the other end is connected with the driving component for driving the main shaft rotation, the grinding head one end away from the driving component has the grinding surface being arranged perpendicularly with the main shaft;It also includes clamping mechanism and feeding mechanism, the clamping hole being arranged in parallel with the main shaft is arranged through on the clamping mechanism, for transversely fixed to be ground rod;The feeding mechanism includes the material containing bin for containing grinding agent and the material collection bin for collecting grinding agent, the material containing bin is located above the grinding head, and it has the material dropping hole being arranged towards the grinding surface;The material collection bin is located directly below the grinding head, and it has the collection port being arranged towards the grinding head.

[0008] With the above structure, to be ground rod is transversely fixed in clamping hole, and the rod end face is abutted on grinding surface, the main shaft is rotated by driving driving component, grinding agent is dropped drop by drop downwards by the material dropping hole of material containing bin, since the material dropping hole is towards grinding surface, so that the dropped grinding agent will be attached on grinding surface, and flow to between grinding surface and rod end face, grinding head rotates relative to to be ground rod, and the rod end face is ground by grinding agent between them, in the process of grinding, grinding agent is continuously dropped drop by drop by material dropping hole, to ensure that there is sufficient grinding agent acting between grinding surface and rod end face, while, under the action of gravity, grinding agent will gradually flow and drop into the material collection bin below.

[0009] Further, the main shaft is arranged eccentrically relative to the clamping hole.

[0010] Further, the material dropping hole of the material containing bin is provided with a glue dispensing valve, and the glue dispensing valve is connected with a drop control system for controlling the glue dispensing valve.

[0011] The glue dispensing valve is widely used in product assembly line, mainly used for precise control of glue dispensing amount, and the glue dispensing valve is installed on the material dropping hole, so that the dispensing amount of grinding agent can be precisely controlled.

[0012] Further, a weighing device is arranged below the material collection bin, the weighing device is connected to the drop control system, and the drop control system is used to receive the weight value detected by the weighing device, and control the glue dispensing valve according to the change amount of weight value.

[0013] In this way, the weight change of the material collection bin can be detected by the weighing device, so as to judge the amount of grinding agent falling or flowing off from the grinding surface, so that the glue dispensing valve can be controlled according to the weight change of the material collection bin.

[0014] Further, the clamping mechanism comprises at least two supporting seats and a pad, the clamping hole comprises a first clamping hole penetratingly arranged on the supporting seat and a second clamping hole penetratingly arranged on the pad, the inner diameter of the first clamping hole matches the outer diameter of the rod to be ground, so that the rod to be ground is clamped in the first clamping hole in an axial movable manner; the inner diameter of the second clamping hole is consistent with the outer diameter of the rod to be ground, and the second clamping hole is fixedly sleeved on the rod to be ground; the pad is connected with one of the supporting seats through an elastic compensation member arranged along the axial direction of the main shaft, so that the rod to be ground clamped on the pad is abutted on the grinding surface towards the grinding head.

[0015] In this way, the elastic compensation member can be used to apply an axial force to the rod to be ground, so as to ensure reliable end face grinding.

[0016] Further, the pad is provided with a guide rod arranged in parallel with the second clamping hole, and a plurality of guide rods are uniformly arranged along the circumferential direction of the second clamping hole; the supporting seat is provided with a guide hole corresponding to the guide rod, and the guide rod is axially movably arranged in the guide hole.

[0017] In this way, the weight of the pad can be applied to the supporting seat through the guide rod by cooperation of the guide rod and the guide hole, so as to avoid that the rod to be ground is subjected to a bending moment due to a radial force applied by the pad.

[0018] Further, the elastic compensation member is a coil spring sleeved on the guide rod.

[0019] Further, the elastic compensation member is arranged on the side of the pad away from the grinding machine; the side of the pad away from the elastic compensation member is provided with a cam mechanism, the cam mechanism comprises a rotating shaft arranged orthogonally to the axis of the second clamping hole and a cam mounted on the rotating shaft, and the cam abuts against the pad; the other end of the rotating shaft is connected with a driving motor through a worm and gear reducer.

[0020] In this way, the cam rotates under the driving of the driving motor, and pushes the pad away from the grinding head, so as to separate the rod to be ground from the grinding surface, and the grinding agent dropped on the grinding surface can flow better between the grinding surface and the end face of the rod to be ground.

[0021] Further, the main shaft and the axis of the clamping hole form an angle of 1-5° with the horizontal plane, and the grinding head is higher than the driving component.

[0022] In this way, the grinding agent can be better dropped on the grinding surface.

[0023] A method for grinding the end face of a Hopkinson pressure bar, characterized in that: first, an end face grinding device for the Hopkinson pressure bar as described above is obtained; the bar to be ground is clamped on a clamping mechanism, and the end face of the bar to be ground is placed against the grinding surface; during grinding, abrasive is first dripped into the grinding surface and the end face of the bar to be ground through a dripping hole, and the grinding machine is started to grind; during the grinding process, abrasive is added through the dripping hole.

[0024] In summary, the present invention has the advantages of ingenious structural design, which can ensure that a sufficient amount of abrasive is applied to the grinding surface, and which helps to reduce the cost of testing. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of Example 1.

[0026] Figure 2 This is a schematic diagram of the structure in the tilted state of Example 1.

[0027] Figure 3 This is a schematic diagram of the structure of Example 2. Implementation

[0028] The present invention will be further described in detail below with reference to the embodiments.

[0029] Example 1: As Figure 1 As shown, a Hopkinson pressure bar end face grinding device includes a grinding machine 1. The grinding machine 1 has a main shaft 2 arranged in a horizontal direction. A grinding head 3 is provided at one end of the main shaft 2, and a drive component 4 for driving the main shaft 2 to rotate is connected to the other end. The end of the grinding head 3 facing away from the drive component 4 has a grinding surface arranged perpendicular to the main shaft 2. It also includes a clamping mechanism 5 and a feeding mechanism 6. The clamping mechanism 5 has a through-hole for horizontally fixing the bar to be ground. The axis of the clamping hole is parallel to the axis of the main shaft 2 and is relatively eccentrically arranged. The feeding mechanism 6 includes a holding bin 61 for holding abrasive and a collecting bin 62 for collecting abrasive. The holding bin 61 is located above the grinding head 3 and has a drip hole facing the grinding surface. The collecting bin 62 is located directly below the grinding head 3 and has a collecting port facing the grinding head 3.

[0030] A dispensing valve is provided on the dispensing hole of the material holding hopper 61, and a dispensing control system for controlling the dispensing valve is connected to the dispensing valve; a weighing device is provided below the material collecting hopper 61, and the weighing device is connected to the dispensing control system. The dispensing control system is used to receive the weight value detected by the weighing device and control the dispensing valve according to the change in weight value.

[0031] The dispensing valve is widely used in product assembly line, mainly used for precise control of glue dispensing operation, the dispensing valve is installed on the material dropping hole, and the material dropping amount of the abrasive can also be precisely controlled. Through the real-time detection of the weight of the material collecting bin by the weighing device, the amount of abrasive falling or flowing from the grinding surface can be calculated, so that the dispensing valve can be controlled to supplement the material according to the weight change of the material collecting bin.

[0032] The clamping mechanism 5 comprises at least two support seats 51 and a cushion block 52, the clamping hole comprises a first clamping hole penetratingly arranged on the support seat 51 and a second clamping hole penetratingly arranged on the cushion block 52, the inner diameter of the first clamping hole matches the outer diameter of the rod to be ground, so that the rod to be ground is clamped in the first clamping hole in an axial movable manner; the inner diameter of the second clamping hole is consistent with the outer diameter of the rod to be ground, and the second clamping hole is fixedly sleeved on the rod to be ground; the cushion block 52 is connected with one of the support seats 51 through an elastic compensation member 53 arranged along the axial direction of the main shaft 2, so that the rod to be ground clamped on the cushion block 52 abuts against the grinding surface towards the grinding head 3.

[0033] The cushion block 52 is provided with a guide rod arranged in parallel with the second clamping hole, and a plurality of guide rods are uniformly arranged along the circumferential direction of the second clamping hole; the support seat 51 is provided with a guide hole corresponding to the guide rod, and the guide rod is movably arranged in the guide hole in an axial direction; the elastic compensation member 53 is a spiral spring sleeved on the guide rod. By matching the guide rod with the guide hole, the weight of the cushion block can be applied to the support seat through the guide rod, so as to avoid the bending moment caused by the radial force applied by the cushion block to the rod to be ground. At the same time, the elastic compensation member applies an axial force to the rod to be ground to ensure reliable end face grinding.

[0034] The elastic compensation member 53 is located on the side of the cushion block 52 away from the grinding machine 1; the side of the cushion block 52 away from the elastic compensation member 53 is provided with a cam mechanism 7, the cam mechanism 7 comprises a rotating shaft arranged orthogonally to the axis of the second clamping hole and a cam installed on the rotating shaft, the cam abuts against the cushion block 52; the other end of the rotating shaft is connected with a driving motor through a worm gear reducer. The cam rotates under the driving of the driving motor, and pushes the cushion block away from the grinding head, so as to separate the rod to be ground from the grinding surface, so that the abrasive falling on the grinding surface can flow better between the grinding surface and the end face of the rod to be ground.

[0035] In specific implementation, as shown in Figure 2 The main shaft 2 and the axis of the clamping hole can also be arranged at an angle of 1-5° with the horizontal plane, and the grinding head 3 is higher than the driving component 4. This can make the abrasive drop better on the grinding surface.

[0036] The end face grinding device in this embodiment grinds the Hopkinson pressure bar using the following steps:

[0037] Step 1: Clamp the rod to be ground onto the clamping mechanism, and fix the pad onto the rod while compressing the helical spring, so that the end of the rod to be ground abuts against the grinding surface of the grinding head.

[0038] Step 2: Before starting the drive unit 4, apply abrasive to the contact point between the grinding head and the rod to be ground through the dripping hole of the material container 61.

[0039] Step 3: Start the drive component 4 to drive the grinding head to rotate at a low speed. The dripping control system controls the dripping speed of the dripping hole according to the interval time set by the program and the data detected by the weighing device, so as to ensure that there is always abrasive on the grinding surface during the grinding process. In addition, when the abrasive is dripped into the dripping hole, the cam mechanism can also push the pad block to separate the rod to be ground from the grinding head, so that the abrasive can flow better between the grinding surface and the end face of the rod to be ground.

[0040] Example 2: As Figure 3 As shown, the main difference between this embodiment and Embodiment 1 is that the clamping mechanism 5 includes at least two support seats 51, a compensation pad 521, and a clamping pad 522. The clamping hole includes a first clamping hole that passes through the support seat 51 and the compensation pad 521 and a second clamping hole that passes through the clamping pad 522. The inner diameter of the first clamping hole matches the outer diameter of the rod to be ground, so that the rod to be ground can be axially moved and clamped in the first clamping hole. The inner diameter of the second clamping hole is consistent with the outer diameter of the rod to be ground and is fixedly fitted on the rod to be ground.

[0041] The compensation pad 521 is located on the side of one of the support seats 51 facing away from the grinding machine 1, and the clamping pad 522 is located on the side of the compensation pad 521 facing the grinding machine 1, and is located between the compensation pad 521 and the adjacent support seat 51; the compensation pad 521 has a guide rod arranged parallel to the first clamping hole, and multiple guide rods are evenly distributed along the circumference of the second clamping hole and facing the grinding machine 1; both the support seat 51 and the clamping pad 522 have guide holes that are matched and matched with the guide rods, and the guide rods are axially movable and pass through the guide holes.

[0042] An elastic compensation element 53 is connected between the compensation pad 521 and the clamping pad 522, which is arranged along the axial direction of the main shaft 2. In this embodiment, the elastic compensation element 53 is a helical spring sleeved on the guide rod.

[0043] The compensation pad 521 is provided with a cam mechanism 7 on the side away from the elastic compensation member 53, the cam mechanism 7 comprises a rotating shaft arranged orthogonally to the axis of the first clamping hole and a cam mounted on the rotating shaft, the cam abuts against the compensation pad 521; the other end of the rotating shaft is connected with a driving motor through a worm gear reducer.

[0044] With the above structure of the embodiment, the cam of the cam mechanism 7 abuts against the compensation pad, so that the compensation pad 521 cannot move away from the grinding machine 1, the compensation pad 521 transmits the pressure to the clamping pad 522 through the coil spring, and the clamping pad 522 drives the rod to be ground to only abut against the grinding surface. When the cam of the cam mechanism 7 rotates, the compensation pad 521 moves axially relative to the rod to be ground and changes the pressure applied to the coil spring, that is, changes the pressure of the rod to be ground abutting against the grinding surface. When the pressure is small, the grinding agent can flow between the grinding surface and the end surface of the rod to be ground, so that the rod to be ground does not need to be completely separated from the grinding surface during the whole grinding process, and the grinding can be better.

[0045] The above only describes the preferred embodiments of the present application and is not limited to the present application. Any modification, equivalent replacement and improvement within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A device for grinding the end face of a Hopkinson pressure bar, characterized in that The grinding machine (1) has a main shaft (2) arranged in horizontal direction, one end of the main shaft (2) is provided with a grinding head (3), the other end is connected with a driving component (4) for driving the main shaft (2) to rotate, the grinding head (3) has a grinding surface arranged perpendicularly to the main shaft (2) at the end away from the driving component (4); further comprising a clamping mechanism (5) and a feeding mechanism (6), the clamping mechanism (5) is provided with a clamping hole arranged in parallel to the main shaft (2) through the clamping mechanism (5), for transversely fixing the rod to be ground; the feeding mechanism (6) comprises a material containing bin (61) for containing grinding agent and a material collecting bin (62) for collecting grinding agent, the material containing bin (61) is located above the grinding head (3) and has a material dropping hole arranged towards the grinding surface; the material collecting bin (62) is located directly below the grinding head (3) and has a collecting opening arranged towards the grinding head (3); the main shaft (2) and the axis of the clamping hole have an included angle of 1-5° with the horizontal plane, and the grinding head (3) is higher than the driving component (4); A glue dispensing valve is arranged on the material dropping hole of the material containing bin (61), the glue dispensing valve is connected with a glue dropping control system for controlling the glue dispensing valve; a weighing device is arranged below the material collecting bin (62), the weighing device is connected to the glue dropping control system, the glue dropping control system is used for receiving the weight value detected by the weighing device, and the glue dropping control system is used for controlling the glue dispensing valve according to the change amount of the weight value; The clamping mechanism (5) comprises at least two supporting seats (51) and pads (52), the clamping hole comprises a first clamping hole arranged through the supporting seat (51) and a second clamping hole arranged through the pad (52), the inner diameter of the first clamping hole matches the outer diameter of the rod to be ground, so that the rod to be ground can be clamped in the first clamping hole in axial direction; the inner diameter of the second clamping hole is consistent with the outer diameter of the rod to be ground, and the second clamping hole is fixedly sleeved on the rod to be ground; the pad (52) and one of the supporting seats (51) are connected with an elastic compensation member (53) arranged in the axial direction of the main shaft (2), so that the rod to be ground clamped on the pad (52) abuts against the grinding surface towards the grinding head (3).

2. The apparatus for grinding the end face of a Hopkinson pressure bar according to claim 1, wherein The main shaft (2) is arranged eccentrically opposite to the clamping hole.

3. The apparatus for grinding the end face of a Hopkinson pressure bar according to claim 1, wherein The pad (52) has a guide rod arranged in parallel to the second clamping hole, the guide rod is uniformly arranged with a plurality of guide rods along the circumference of the second clamping hole; the supporting seat (51) has a guide hole arranged in corresponding matching with the guide rod, and the guide rod is arranged in the guide hole in axial direction.

4. The apparatus for grinding the end face of a Hopkinson pressure bar according to claim 3, wherein The elastic compensation member (53) is a spiral spring sleeved on the guide rod.

5. The apparatus for grinding the end face of a Hopkinson pressure bar according to claim 1, wherein The elastic compensation piece (53) is located on the side of the cushion block (52) away from the grinder (1); the side of the cushion block (52) away from the elastic compensation piece (53) is provided with a cam mechanism (7), the cam mechanism (7) comprises a rotating shaft arranged orthogonally to the axis of the second clamping hole and a cam mounted on the rotating shaft, and the cam abuts against the cushion block (52); the other end of the rotating shaft is connected with a driving motor through a worm gear reducer.

6. A method of end face grinding of a Hopkinson pressure bar, characterized by, The end face grinding device of the Hopkinson pressure bar is obtained first; the rod to be ground is clamped on the clamping mechanism, and the end face of the rod to be ground abuts against the grinding face; during grinding, the grinding agent is first dropped between the grinding face and the end face of the rod to be ground through the dropping hole, the grinder is started to grind, and the grinding agent is added through the dropping hole during grinding. The end face grinding device of the Hopkinson pressure bar is obtained first; the rod to be ground is clamped on the clamping mechanism, and the end face of the rod to be ground abuts against the grinding face; during grinding, the grinding agent is first dropped between the grinding face and the end face of the rod to be ground through the dropping hole, the grinder is started to grind, and the grinding agent is added through the dropping hole during grinding.

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