An accelerated fatigue test device for solid propellant grains

Abstract

The present invention relates to an accelerated fatigue test device for a solid propellant grain, comprising a base frame, a stepper motor, a traction pair, a rear clamp, a ball screw, a front clamp, a fixed slide and a movable slide, wherein the base frame is fixed on a foundation, and a fixed motor seat, a support seat and a tail seat are sequentially installed on the base frame; the stepper motor is installed and fixed on the motor seat; the fixed slide is installed and fixed on the support seat, the movable slide is embedded and connected with the fixed slide, and a traction pair is installed at one end of the movable slide, and the traction pair is embedded and connected with the ball screw; the front clamp and the rear clamp are respectively fixed on the movable slide and the tail seat, and the two ends of the grain test piece are respectively embedded in the grooves of the front clamp and the rear clamp, and a rubber pad and a cover plate are sequentially placed on them for fixing. The present invention has the characteristics of low cost, simple structure, convenient adjustment, etc., and is easy to realize the accelerated fatigue test of a solid propellant grain test piece with small amplitude, low frequency and multiple combined test conditions of amplitude and frequency under the same test installation state.

Description

Technical Field

[0001] The invention relates to a testing device, in particular to an accelerated fatigue testing device for a solid propellant charge. Background Art

[0002] In order to achieve rapid response strike capability, current tactical weapons use solid propellants as fuel supply. With the changes in military industry and national defense strategic needs, a large number of weapons have entered the long-term storage stage. Therefore, the life assessment and safe use limits of solid propellants have become a hot topic and focus of research. The propellant accelerated fatigue test device is designed to carry out research on a sub-item of this project.

[0003] Existing mechanisms for realizing accelerated fatigue test of solid propellant grain test pieces include mechanical cams, crank slider connecting rods, etc., which generally convert mechanical rotational motion into the linear reciprocating motion required for accelerated fatigue test of propellant grain test pieces. The former is the most similar to the present invention, that is, the fatigue linear reciprocating motion of the propellant grain test piece is realized by changing the displacement of the outer contour of the cam.

[0004] The existing crank slider connecting rod mechanism is large in size and has large motion inertia. At the same time, its quick return characteristics can easily cause structural damage to the solid propellant grain test piece. The motion amplitude and frequency of the mechanical cam mechanism are not easy to change, the contact gap of the moving pair is large and easy to wear, and it is not suitable for use in the small amplitude (1mm~4mm) and low speed range. In addition, the rotation of the cam will produce lateral bending stress on the solid propellant grain test piece, which is not the original intention of the accelerated fatigue test research of the solid propellant grain test piece. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an accelerated fatigue test device for solid propellant grains, which is used to realize accelerated fatigue testing of solid propellant grain test pieces, so as to solve the problem of accelerated aging testing of propellant grain test pieces with small amplitude and low frequency requirements, and provide a reference for propellant life assessment and safety limit of use.

[0006] In order to solve the existing technical problems, the technical solution adopted by the present invention is: an accelerated fatigue test device for solid propellant grains, comprising a base frame, a stepping motor, a traction pair, a rear clamp, a ball screw, a front clamp, a fixed slide and a movable slide.

[0007] The base frame is fixed on the foundation, and the motor seat, the support seat and the tail seat are sequentially installed on the base frame;

[0008] The stepper motor is mounted and fixed on the motor seat, and the motor shaft of the stepper motor is connected to one end of the ball screw;

[0009] The fixed slide is fixedly mounted on the support seat, the movable slide is embedded in the fixed slide and forms a sliding motion pair, and a traction pair is installed at one end of the movable slide facing the stepper motor; a bearing seat is installed at one end of the support seat facing the stepper motor, and a bearing is installed in the bearing seat; one end of the ball screw is connected to the motor shaft of the stepper motor, and the other end is fixed in the bearing of the support seat bearing seat; the traction pair is embedded in the ball screw, and when the stepper motor rotates, the ball screw rotates synchronously to drive the traction pair and bring the movable slide to reciprocate linearly on the fixed slide;

[0010] The front clamp and the rear clamp are fixed on the movable slide and the tailstock respectively, and the two ends of the drug column test piece are respectively embedded in the grooves of the front clamp and the rear clamp, and the rubber pad and the cover plate are placed on them in turn for fixing.

[0011] The accelerated fatigue test device of the present invention performs reciprocating fatigue tests on solid propellant grain test pieces by adopting the principle of converting rotational motion into linear reciprocating motion. It has the characteristics of compact structure, low cost and small motion inertia, and is suitable for the test requirements of fatigue conditions with small amplitude, low frequency and multiple combinations of amplitude and frequency.

[0012] 1) The movement amplitude and frequency parameters of the device are adjusted and controlled by a controller or an electrical appliance with the same function.

[0013] 2) The test conditions corresponding to various combinations of the device's motion amplitude and frequency can be achieved by modifying the parameters of the controller online.

[0014] 3) The stepper motor shaft of the device is threadedly connected to one end of the ball screw, and an anti-backlash nut is provided on the motor shaft to reversely lock and eliminate thread gap.

[0015] 4) The other end of the ball screw of the device is supported by a bearing, the shaft shoulder contacts the inner ring of the bearing, a groove is set at the shaft end and a retaining ring is embedded, and finally it is sealed with a bearing end cover.

[0016] 5) In this device, the movable slide and the fixed slide are embedded in each other to form a linear motion pair, and lubricating oil is dripped between the motion pairs for lubrication.

[0017] 6) The two ends of the solid propellant grain test piece in the device are respectively embedded in the grooves of the front and rear fixtures, with a rubber pad on the top and pressed tightly with a cover plate.

[0018] 7) In addition to being ensured by machining accuracy, the coaxiality of all coaxial connectors in the device can be adjusted by using the gap adjustment of the circular light holes and rectangular holes on the components, and the height direction can be adjusted using adjustment gaskets when necessary.

[0019] Beneficial Effects

[0020] The invention provides a solid propellant grain accelerated fatigue testing device, which can realize small-amplitude, low-frequency linear reciprocating fatigue motion of a solid propellant grain test piece at a relatively low cost, and can realize various combination test conditions of amplitude and frequency by changing the parameters of a stepper motor controller. There is no lateral bending stress on the test piece, the inertia of the motion mechanism is small, and it is not easy to cause structural damage to the test piece.

[0021] The present invention has the characteristics of low cost, simple structure, convenient adjustment, etc., and can easily realize the accelerated fatigue test of solid propellant grain test pieces with small amplitude and low frequency as well as various amplitude and frequency combination test conditions under the same test installation state. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the frame structure of the accelerated fatigue test device, which includes: a frame 1, a base 1.1, a leg 1.2, a side plate 1.3, a short-rib square steel tube 1.4, a base plate 1.5 and a long-rib square steel tube 1.6;

[0023] Figure 2 This is a front view of the accelerated fatigue test device, which includes: a motor base 2, a bottom plate 2.1, a rib plate 2.2, a vertical plate 2.3, screws 3, a stepper motor 4, screws 5, a traction pair 7, screws 8, a rear clamp 9, and a support base 11;

[0024] Figure 3 The rear view of the accelerated fatigue test device includes: a bottom plate 11.1, a lower rib plate 11.2, a vertical plate 11.3, an upper rib plate 11.4, a top plate 11.5, screws 12, screws 13, screws 14, and a tailstock 15;

[0025] Figure 4 for Figure 1 The schematic diagram of the partial structure of the AA section includes: a ball screw 16, a bearing 18, a bearing cover 19, and a shaft retaining ring 20;

[0026] Figure 5 for Figure 2 A schematic diagram of a partial structure of the middle BB section, including: a cover plate 21, a front clamp 22, a fixed slide 23, a movable slide 24, a screw 25, and a propellant charge test piece 26;

[0027] Figure 6 for Figure 1 The local structure view in the middle C direction includes: anti-backlash nut 6;

[0028] Figure 7 This is a schematic diagram of the propellant grain test piece;

[0029] Figure 8 Schematic diagram of the rear fixture;

[0030] Fig. 9 Schematic diagram of the front clamp. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0032] The detailed implementation scheme of the present invention is as follows:

[0033] A solid propellant grain accelerated fatigue test device mainly includes a base frame 1, a motor seat 2, a stepper motor 4, an anti-backlash nut 6, a traction pair 7, a rear clamp 9, a support seat 11, a tail seat 15, a ball screw 16, a bearing 18, a bearing cover 19, a shaft retaining ring 20, a cover plate 21, a front clamp 22, a fixed slide 23, a movable slide 24, a propellant grain test piece 26, a rubber pad 27 and screws 3, 5, 8, 10, 12, 13, 14, 25 and the like.

[0034] like Figure 1 As shown, the base frame 1 is fixed to the ground foundation or other foundation through the anchor holes; the base frame 1 is welded by anchors 1.1, legs 1.2, side plates 1.3, short-rib square steel pipes 1.4, base plates 1.5 and long-rib square steel pipes 1.6.

[0035] like Figure 2 As shown, the motor base 2 is fixed to the base frame 1 by screws 3; the motor base 2 is formed by welding the bottom plate 2.1, the rib plate 2.2, and the vertical plate 2.3; the stepper motor 4 is fixed to the motor base 2 by screws 5.

[0036] like Figure 3 As shown, the support seat 11 is fixed to the base frame 1 by screws 12; the support seat 11 is formed by welding a bottom plate 11.1, a rib plate 11.2, a vertical plate 11.3, a rib plate 11.4, and a top plate 11.5, wherein the vertical plate close to the stepper motor side is provided with a bearing seat.

[0037] like Figure 3 As shown, the tailstock 15 is fixed on the base frame 1 by screws 12; the tailstock 15 is formed by welding a vertical plate 15.1, a rib plate 15.2, and a bottom plate 15.3.

[0038] like Figure 4 As shown, one end of the ball screw 16 is connected to the shaft of the stepper motor 4 through a thread, and the other end is fixed in the bearing seat of the support seat 11; the shaft shoulder of the ball screw 16 cooperates with the inner ring of the bearing 18, the outer ring of the bearing 18 cooperates with the side of the bearing seat, and the shaft retaining ring 20 is embedded in the groove at the end of the ball screw; the bearing end cover 19 is connected to the bearing seat by a screw 17.

[0039] like Figure 6 As shown, the anti-backlash nut 6 is threadedly connected to the shaft of the stepper motor 4 and is reversely locked after the ball screw 16 is connected to the stepper motor 4.

[0040] like Figure 2 and Figure 5 As shown, the traction pair 7 is embedded with the ball screw 16, and the traction pair 7 is connected to the movable slide 24 via the screw 8; the movable slide 24 is embedded with the fixed slide 23 (the cross section is as shown in FIG. Figure 5 ), forming a sliding motion pair; the fixed slide groove 23 is fixed to the support seat 11 by screws 14.

[0041] like Figure 5 and Figure 7-9 As shown, the two ends of the drug column test piece 26 are respectively embedded in the grooves of the front clamp 22 and the rear clamp 9, and the rubber pads 27 are placed on them in turn, and then the cover plate 21 is fixed to the front and rear clamps by screws 13; the front and rear clamps are respectively fixed to the movable slide groove 24 and the tailstock 15 by screws 22.

[0042] Working principle: When the controller drives the stepper motor to rotate, the ball screw rotates synchronously to drive the traction pair, movable slide, and grain test piece assembly to reciprocate linearly. The amplitude is adjusted by changing the number of pulses sent by the controller to the stepper motor, and the reciprocating motion frequency is adjusted by changing the pulse frequency sent by the controller to the stepper motor, ultimately completing the accelerated fatigue test of the solid propellant grain test piece.

[0043] The present invention can form a new solid propellant grain accelerated fatigue test device by changing the cross-sectional shape of the moving slide and the fixed slide, changing the ball screw to other types of screws, changing the shape of the support seat, or changing one or more of the connection methods. From the perspective of use, it can also be promoted and applied to fatigue tests of other materials with similar performance to solid propellants. The present invention has been verified by actual operation and fully meets the requirements of accelerated fatigue tests of solid propellant grain test pieces.

Claims

1. An accelerated fatigue test device for a solid propellant charge, comprising a base frame (1), a stepping motor (4), an anti-backlash nut (6), a traction pair (7), a rear clamp (9), a ball screw (16), a front clamp (22), a fixed slide groove (23) and a movable slide groove (24), characterized in that ； The base frame (1) is fixed on the foundation, and the motor base (2), the support base (11) and the tail base (15) are sequentially installed on the base frame (1); The stepper motor (4) is mounted and fixed on the motor base (2), and the motor shaft of the stepper motor (4) is connected to one end of the ball screw (16); The fixed slide groove (23) is fixedly mounted on the support seat (11), the movable slide groove (24) is embedded in the fixed slide groove (23) and forms a sliding motion pair, and a traction pair (7) is installed at one end of the movable slide groove (24) facing the stepper motor (4); a bearing seat is installed at one end of the support seat (11) facing the stepper motor (4), and a bearing (18) is installed in the bearing seat; one end of the ball screw (16) is connected to the motor shaft of the stepper motor (4), and the other end is fixed in the bearing (18) of the bearing seat of the support seat (11); the traction pair (7) is embedded in the ball screw (16), and when the stepper motor (4) rotates, the ball screw (16) rotates synchronously to drive the traction pair (7) and drive the movable slide groove (24) to move linearly back and forth on the fixed slide groove (23); The front clamp (22) and the rear clamp (9) are respectively fixed on the movable slide groove (24) and the tailstock (15), and the two ends of the drug column test piece (26) are respectively embedded in the grooves of the front clamp (22) and the rear clamp (9), and the rubber pad (27) and the cover plate (21) are placed on them in turn for fixing; The anti-backlash nut (6) is threadedly connected to the shaft of the stepping motor (4) and is reversely locked after the ball screw (16) is connected to the stepping motor (4).

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