Projectile diameter variable reluctance launching device suitable for Hopkinson bar test

Abstract

The utility model relates to a variable projectile diameter reluctance launcher suitable for Hopkinson bar test, which comprises an inner trajectory replaceable device, a hollow iron yoke and a coil positioned in the iron yoke, the coil is connected with a direct current power supply through a direct current boost switch power supply, two ends of the iron yoke are provided with iron yoke holes matched with inner holes of the coil, and the iron yoke holes are connected with the coil. The iron yoke hole and the coil inner hole form a mounting hole, the inner ballistic replaceable device is detachably and fixedly connected in the mounting hole, and the center of the inner ballistic replaceable device is provided with a projectile hole coaxial with the mounting hole. The device has the advantages of being small in size, controllable in speed, controllable in impact time, environmentally friendly, low in noise and the like, the projectile launching speed is controllable, the stress wave amplitude value pulse width is adjustable, and the device can be suitable for launching projectiles with different diameters.

Description

TECHNICAL FIELD

[0001] The utility model relates to the hopkinson bar test field, specifically be applicable to hopkinson bar test projectile diameter variable magnetic resistance launching device. BACKGROUND

[0002] Hopkinson bar test is applicable to high strain rate test, and with static test, with the increase of strain rate, stress wave effect is more obvious, and the stress-strain relationship of test piece is obtained by utilizing stress wave information that propagates in test bar. UTILITY MODEL CONTENTS

[0003] The utility model provides a kind of suitable for hopkinson bar test projectile diameter variable magnetic resistance launching device for the deficiency of prior art, with the advantages of no noise, good safety performance, projectile speed easy control, suitable for different projectile diameters.

[0004] The utility model is realized by the following technical scheme, provide a kind of suitable for hopkinson bar test projectile diameter variable magnetic resistance launching device, including interior ballistic replaceable device, hollow yoke and the coil in the yoke, the coil is connected with direct current power supply by direct current boost switch power supply, the yoke hole that is adapted with the inner hole of coil is opened in the both ends of yoke, the yoke hole and the inner hole of coil constitute mounting hole, the interior ballistic replaceable device can be detachably fixed in mounting hole, the projectile hole that is coaxial with mounting hole is opened in the center of interior ballistic replaceable device.

[0005] As optimization, the interior ballistic replaceable device includes the center tube in mounting hole, the fixed end plate fixed in one end of center tube and the movable end plate detachably fixed in the other end of center tube, fixed end plate and movable end plate are respectively attached in the both ends of yoke, and the inner hole of center tube is projectile hole.

[0006] As optimization, the movable end plate is connected with center tube by thread.

[0007] As optimization, the center tube includes insulating sleeve and ferromagnetic tube fixed in the both ends of insulating sleeve.

[0008] As optimization, the distance from the end of insulating sleeve to fixed end plate and the distance from the end of insulating sleeve to movable end plate are equal to the length of yoke hole.

[0009] The utility model discloses a beneficial effect is: the utility model discloses a kind of variable diameter magnetic resistance launching device suitable for hopkinson bar test projectile, adopt direct-current power supply, make magnetic resistance launch control simple, projectile launch speed controllable, stress wave amplitude width adjustable, by replacement interior ballistic replaceable device, the launch of different diameter projectile is realized, noise is small, no pollution, device mobility is good. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 It is use state diagram of the utility model;

[0011] Figure 2 It is interior section view of the utility model;

[0012] Figure 3 It is coil section view of the utility model;

[0013] Figure 4 It is iron yoke section view of the utility model;

[0014] Figure 5 It is interior ballistic replaceable device section view of the utility model;

[0015] As shown in the figure:

[0016] 1, projectile, 2, interior ballistic replaceable device, 21, insulating sleeve, 22, fixed end plate, 23, first ferromagnetic tube, 24, second ferromagnetic tube, 25, movable end plate, 3, iron yoke, 4, coil, 5, pulse shaper, 6, incident bar, 7, first strain gauge, 8, test piece, 9, transmission bar, 10, second strain gauge, 11, absorption bar, 12, buffer block. DETAILED DESCRIPTION

[0017] To clearly illustrate the technical features of the scheme, below through specific implementation, the scheme is described.

[0018] Theoretical basis of the utility model:

[0019] Direct-current power supply voltage, DC-DC direct-current switching power supply duty ratio and voltage after boosting are respectively U in 、 D y And U out , electromagnetic force acting on projectile is

[0020] (1)

[0021] W m 、 、 R m、 N 、 i, μ 0、 s AndR These are, respectively, magnetic field energy, magnetic flux, magnetic circuit reluctance, number of coil turns, loop current, vacuum permeability, projectile cross-sectional area, and loop resistance. From equation (1), it can be seen that when the coil structure is fixed, by adjusting U... in and D y Achieve controllable projectile firing rate.

[0022] like Figures 1-5 As shown, this utility model provides a variable reluctance launching device for Hopkinson rod test projectiles, including an internal ballistic replaceable device 2, a hollow iron yoke 3, and a coil 4 located inside the iron yoke 3. Only the first-stage launching coil is shown in the figure, but multiple stages of coils can be used for launching according to the launching requirements.

[0023] The iron yoke 3 has a cylindrical hollow structure, such as... Figure 4 As shown, the outer diameter and thickness of the iron yoke are respectively d 5. and L 2. The inner diameter of the iron yoke is d As described in 4, Figure 3 As shown, the outer diameter of coil 4 is equal to the inner diameter of the yoke, and both are [missing information]. d 4. The length of coil 4 is equal to the length inside the yoke and both are... L 3.

[0024] The coil 4 is connected to a DC power supply via a DC boost switching power supply, thereby allowing the DC voltage to be adjusted.

[0025] The yoke 3 has yoke holes at both ends that fit the inner holes of the coil 4. The diameters of the inner holes of the coil 4 and the yoke holes are both... d 2. And coaxial setup.

[0026] The yoke hole and the inner hole of the coil 4 form a mounting hole. The inner ballistic replacement device 2 is detachably fixed in the mounting hole. The inner ballistic replacement device 2 has a projectile hole coaxial with the mounting hole in its center.

[0027] Specifically, such as Figure 5 As shown, the internal ballistic replaceable device 2 includes a central tube located in the mounting hole, a fixed end plate 22 fixed to one end of the central tube, and a movable end plate 25 detachably fixed to the other end of the central tube. In this embodiment, the movable end plate 25 is connected to the central tube by threads.

[0028] The fixed end plate 22 and the movable end plate 25 are respectively attached to both ends of the iron yoke 3, and the inner hole of the central tube is a shot hole.

[0029] In this embodiment, the central tube includes an insulating sleeve 21 and ferromagnetic tubes fixed to both ends of the insulating sleeve 21. In this embodiment, the insulating sleeve 21, the fixed end plate 22, and the movable end plate 25 are made of epoxy resin material.

[0030] In this embodiment, a first ferromagnetic tube 23 is bonded and fixed to one end of the insulating sleeve 21, and a second ferromagnetic tube 24 is bonded and fixed to the other end. The first ferromagnetic tube 23 is bonded to the fixed end plate 22, and the second ferromagnetic tube 24 is threaded to the movable end plate 25.

[0031] The distance from the end of the insulating sleeve 21 to the fixed end plate 22 and the distance from the end of the insulating sleeve 21 to the movable end plate 25 are both equal to the length of the yoke hole. The first ferromagnetic tube 23, the second ferromagnetic tube 24, and the yoke bind the magnetic lines of force and eliminate magnetic leakage.

[0032] How to use this utility model:

[0033] like Figure 1 As shown, a pulse shaper 5, an incident rod 6, a test piece 8, a transmission rod 9, an absorption rod 11, and a buffer block 12 are sequentially arranged behind the projectile outlet along the projectile's ejection direction. A first strain gauge 7 and a second strain gauge 10 are respectively mounted on the incident rod 6 and the transmission rod 9. After the projectile 1 is ejected, it impacts the incident rod 6.

[0034] The amplitude of stress waves increases with the projectile's impact velocity and mass. The projectile's impact velocity and impact area also affect the pulse width of the stress waves. The influence of different head projectile shapes on stress waves can be analyzed by specific kinetic energy.

[0035] (2)

[0036] In the formula, k, M, S and v are the specific kinetic energy, the projectile kinetic energy, the collision contact area and the projectile velocity, respectively.

[0037] As can be seen from the above, the amplitude and pulse width of the stress wave can be modulated by changing the projectile velocity, projectile mass, and projectile head shape.

[0038] By outputting a PWM signal from the transmitter controller to control the step-up and step-down of the DC boost circuit and the on / off timing of each stage of the multi-stage coil launcher via the IGBT, the launch speed of the projectile can be controlled, thus changing the kinetic energy of the projectile. Therefore, the amplitude and pulse width of the stress wave generated by the collision between the projectile and the incident rod can be changed, achieving the purpose of stress wave modulation.

[0039] The projectile is launched through the projectile hole of the internal ballistic replaceable device 2, and projectiles of different diameters can be launched by replacing the internal ballistic replaceable device 2.

[0040] Of course, the above description is also not limited to the above examples, the technical features not described in the utility model can be realized by or using the prior art, which will not be repeated here; the above embodiments and drawings are only used to illustrate the technical scheme of the utility model and are not a limitation on the utility model, the utility model has been described in detail with reference to the preferred embodiments, and those skilled in the art should understand that the changes, modifications, additions or replacements made by those skilled in the art within the essential scope of the utility model do not deviate from the purpose of the utility model, and should also belong to the protection scope of the claims of the utility model.

Claims

1. A variable magnetoresistive launching device for projectiles with a Hopkinson rod test, characterized in that: The application relates to an inner ballistic replaceable device (2), a hollow iron yoke (3) and a coil (4) in the iron yoke (3), wherein the coil (4) is connected with a direct current power supply through a direct current boost switch power supply, the iron yoke (3) is provided with iron yoke holes at two ends and matched with inner holes of the coil (4), the iron yoke holes and the inner holes of the coil (4) form mounting holes, the inner ballistic replaceable device (2) is detachably fixed in the mounting holes, and a projectile hole coaxial with the mounting holes is formed in the center of the inner ballistic replaceable device (2).

2. A magnetic resistance launching device with variable projectile diameter for Hopkinson bar test according to claim 1, characterized in that: The inner ballistic replaceable device (2) comprises a center tube in the mounting holes, a fixed end plate (22) fixed at one end of the center tube and a movable end plate (25) detachably fixed at the other end of the center tube, the fixed end plate (22) and the movable end plate (25) are respectively attached to two ends of the iron yoke (3), and an inner hole of the center tube is the projectile hole.

3. A variable diameter magnetic resistance launching device for split Hopkinson bar testing according to claim 2, wherein: The movable end plate (25) is connected with the center tube through threads.

4. The variable diameter magnetic resistance projectile launching device for split Hopkinson bar testing of claim 2, wherein: The center tube comprises an insulating sleeve (21) and ferromagnetic tubes fixed at two ends of the insulating sleeve (21).

5. A variable diameter magnetic resistance launching device for use in a split Hopkinson pressure bar test according to claim 4, wherein: The distance from the end of the insulating sleeve (21) to the fixed end plate (22) and the distance from the end of the insulating sleeve (21) to the movable end plate (25) are equal to the length of the iron yoke hole.

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