CN101329238A - Loading device applied to friction testing machine - Google Patents

Abstract

The present invention relates to a load pulsation loading device, wherein a pin sample fixture of the device is fixed at one end of a force transmission rod, and the rod body of the force transmission rod is assembled on the body of the loading device through a bearing in a manner of linear movement in the axial direction, and a set of constant load loading devices is arranged on the body of the loading device at the other end of the force transmission rod, and a load output head of the constant load loading device loads a constant pressure on the end face of the end head, and a set of flexible pulsation generating mechanisms is also added to the constant load loading device, and the flexible pulsation output of the flexible pulsation generating mechanism is superimposed on the load of the constant load loading device and applied to the corresponding end face of the force transmission rod through the load output head of the constant load loading device. The present invention inherits the characteristics of simple, easy to implement and easy to control of traditional mechanical impact loading, and at the same time utilizes the flexible loading characteristics of the spring to reduce the noise generated by the impact loading.

Description

Loading device applied to friction testing machine

technical field

The invention relates to a load loading device applied to a friction testing machine, which belongs to the technical field of machinery.

Background technique

Pulsating loading or pulsating impact loading is a commonly used loading form in experiments and practical engineering, and it is an important means to study the performance of materials under impact conditions. The ways to realize pulsating loading include electromagnetic loading method, hydraulic method and traditional mechanical method. Electromagnetic loading method The pulsating load excitation signal is greatly disturbed by the outside world, the loading force is not easy to control, and the loading force is small; the pulsating loading is realized by the hydraulic method, the system response is slow and easy to lag, and high-frequency loading cannot be realized; traditional mechanical loading mostly uses polarization Or transmission type, the disadvantage is that the frequency and loading size are not easy to adjust, and the noise is relatively large during use.

The application of pulsating impact loading in the friction and wear testing machine is mainly to simulate the flexible fluctuation of the electric power line when the skateboard slides and the flexible impact of the locomotive vibration and the fluctuation of the lifting force of the pantograph on the skateboard. In the existing friction and wear test equipment, there are two loading methods: one is completely constant load loading, and pulsating impact cannot be loaded. In the test, only the influence of pantograph lifting force on the slide plate and wire can be simulated, and various impacts cannot be investigated. The impact of load; another loading method is to add a spring to the pin sample fixture on the basis of constant load loading to reduce the impact of the contact vibration on the pin sample during the test and simulate the flexible contact of the wire, but The elastic force generated by the spring is entirely derived from passively bearing the impact force from the pin sample, and the elastic force generated by the spring is uncontrollable, and it is impossible to apply pulsating impact loads with different rules (waveforms).

Contents of the invention

In order to solve the disadvantages of the above-mentioned prior art, the task of the present invention is to provide a load pulsation loading device to achieve adjustable loading force and loading frequency and reduce impact noise.

In order to accomplish the above tasks, the technical solution of the present invention is: a load pulsation loading device, the pin sample fixture is fixed on one end of the dowel bar, and the rod body of the dowel bar is assembled on the side of the loading device through bearings in a manner of moving linearly in the axial direction. On the body, a set of constant load loading device is installed on the body of the loading device at the other end of the dowel bar. The load output head of the constant load loading device loads constant pressure on the end face of the end. There is a set of flexible pulsation generating mechanism, the flexible pulsation output of the flexible pulsation generating mechanism is superimposed on the load of the constant load loading device, and then applied to the corresponding end surface of the dowel bar through the load output head of the constant load loading device.

The flexible pulsation generating mechanism is composed of a reciprocating motion generator and a flexible reciprocating push rod that cooperates with the reciprocating motion generator. One end of the push rod cooperates with the reciprocating motion generator for reciprocating transmission, and the other end of the push rod is connected to the The load loading end of the constant load loading device or the drive connection of the load output head.

The reciprocating motion generator is composed of a motor fixed on the body of the loading device and a cam assembled on its rotating shaft.

The flexible reciprocating push rod is composed of a push rod and a flexible buffer mechanism arranged in series on the push rod.

The flexible buffer mechanism is mainly composed of a pair of sub-mother casings spirally butted together in the direction of the push rod, a buffer spring and a push rod. The tail end of the sub-sleeve is fixed with the push rod, and the buffer spring is inserted in the In the tail section of the casing, one end of the ejector rod is slidably inserted into the first section of the sub casing and press-fitted with the buffer spring. The other end of the ejector rod is rolled and fitted with the cam through the installed roller. The ejector rod and the female casing The port position of the anti-disengagement fit.

The constant load loading device is composed of a crank lever and a weight. The inflection point of the crank lever is rotated and assembled on the body of the loading device. One end of the crank lever is used as a load output head, and the other end is equipped with a Load weights.

The tail end of the push rod of the flexible buffer mechanism is connected together with the weight assembly forging of the crank lever through the connecting seat.

The invention is a new pulsating impact loading method formed on the basis of the existing mechanical loading method. It retains the simple, easy-to-implement, and easy-to-control characteristics of traditional mechanical impact loading, and at the same time uses the flexible loading method to truly simulate the contact mode of the pantograph-catenary system, so that the testing machine with the above-mentioned loading device can be used to solve the problem of the panto-catenary system. Friction and wear problems. It has the following characteristics:

(1) Various forms of pulsating loads can be loaded. Traditional mechanical pulsating loading can only provide simple loading force as sine or cosine, and impact loading method. This invention utilizes the change of external dimensions of the continuously variable radius cam when it rotates one revolution to act on the compression spring in contact with the cam. , the loading force is provided by a compression spring. By changing the shape of the cam, various forms of loading loads can be obtained. (2) Different loading loads can be obtained. By changing springs with different elastic coefficients, different loading forces can be obtained. The larger the elastic coefficient, the greater the force provided by the spring when it compresses the same length. (3) The pulsating loading frequency can be easily controlled. The invention utilizes a frequency-variable motor to drive the continuously variable-radius cam to rotate, and changes the rotational speed of the motor through a frequency converter to realize different loading frequencies. (4) Reduced loading noise. A rolling bearing is added at the contact between the cam and the compression spring to change the sliding friction into rolling friction, which not only reduces the friction energy loss and friction heat generation at the contact, but also greatly reduces the friction noise.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is an assembly relationship diagram between the cam and the ejector rod in Fig. 1 .

Detailed ways

As shown in Figure 1 and Figure 2, in this load pulsating loading device, the pin sample fixture 1 is fixed on one end of the dowel bar 2, and the rod body of the dowel bar 2 is assembled on the loading device through the bearing 3 in a manner of moving linearly in the axial direction. On the main body, a set of constant load loading device is arranged on the body of the loading device at the other end of the dowel bar 2. The load output head 4 of the constant load loading device loads a constant pressure on the end face of the end. A set of flexible pulsation generating mechanism is added, the flexible pulsation output of the flexible pulsation generating mechanism is superimposed on the load of the constant load loading device, and then applied to the corresponding end surface of the dowel bar through the load output head of the constant load loading device. The flexible pulsation generating mechanism is composed of a reciprocating motion generator and a flexible reciprocating push rod that cooperates with the reciprocating motion generator. One end of the push rod cooperates with the reciprocating motion generator for reciprocating transmission, and the other end of the push rod is connected to the constant load. The load loading end of the device or the drive connection of the load output head. In this embodiment, the reciprocating motion generator is composed of a motor 6 fixed on the body of the loading device and a cam 8 assembled on its rotating shaft 7 . The flexible reciprocating push rod is composed of the push rod 5 and the flexible buffer mechanism arranged in series on the push rod. In this embodiment, the flexible buffer mechanism is mainly composed of a pair of sub-mother casings 11, 12, a buffer spring 9 and a push rod 10 that are spirally butted together in the direction of the push rod. The tail end of the sub-sleeve 11 and the push rod 5 are fixed on the Together, the buffer spring 9 is inserted into the tail section of the sub-sleeve 11, and one end of the push rod 10 is slidably inserted into the first section of the sub-sleeve 11 and press-fitted with the buffer spring 9, and the other end of the push rod 10 is installed by Roller 13 and cam 8 are rolling fit, and push rod 10 is anti-disengagement fit with the port position of female casing 12. The constant load loading device is composed of a crank arm type loading rod 15 and a weight 16. The inflection point of the crank arm type loading rod 15 is rotated and assembled on the body of the loading device, and one end of the crank arm type loading rod 15 is used as the load output head 4 , the other end is equipped with loading weight 16. The tail end of the push rod 5 of the flexible buffer mechanism is connected together with the weight assembly section of the crank arm type loading rod through the connecting seat 17 .

The present invention uses the weight 16 to apply a constant load, the flexible pulsation generating mechanism is fixed together with the loading rod 15 through the connecting seat 17, and the load generated by the rotating compression spring 9 of the cam 14 is transmitted to the loading rod 15 through the connecting seat 17, and then transmitted through the loading rod to the pin sample.

Claims (7)

1. A load loading device applied to a friction testing machine. The pin sample fixture is fixed at one end of the dowel bar. The body of the dowel bar moves linearly in the axial direction and is assembled on the body of the loading device through bearings. The force transmission The body of the loading device at the other end of the rod is provided with a set of constant load loading device. The load output head of the constant load loading device loads a constant pressure on the end face of the end. It is characterized in that a constant load loading device is also provided with a Set of flexible pulsation generating mechanism, the flexible pulsation output of the flexible pulsation generating mechanism is superimposed on the load modulation of the constant load loading device, and then applied to the corresponding end surface of the dowel bar through the load output head of the constant load loading device. 2. The load loading device applied to a friction testing machine according to claim 1, characterized in that, the flexible pulsation generating mechanism is composed of a pulsation source and a flexible push rod that cooperates with the pulsation source, and the push rod One end of the push rod is connected with the drive of the pulsation source, and the other end of the push rod is connected with the load loading end of the constant load loading device or the load output head. 3. The load loading device applied to a friction testing machine according to claim 2, wherein the pulse source is composed of a motor fixed on the body of the loading device and a cam assembled on its rotating shaft. 4. The load loading device applied to a friction testing machine according to claim 2 or 3, wherein the flexible push rod is composed of a push rod and an elastic buffer mechanism arranged in series on the push rod. 5. The load loading device applied to a friction testing machine according to claim 4, characterized in that, the elastic buffer mechanism is composed of a pair of female and female sleeves, a buffer spring and a push rod that are screwed together in the direction of the push rod As the main structure, the tail end of the sub-sleeve is fixed with the push rod, the buffer spring is inserted in the tail section of the sub-sleeve, and one end of the ejector rod is slidably inserted in the first section of the sub-sleeve and pressed against the buffer spring Cooperate, the other end of ejector rod is rolled and matched with cam through the installed roller. 6. The load loading device applied to a friction testing machine according to claim 5, wherein the constant load loading device is composed of an "L"-shaped lever and a weight, and the inflection point of the "L"-shaped lever Rotationally assembled on the body of the loading device, one end of the "L"-shaped lever is used as a load output head, and the other end is equipped with a loading weight. 7. The load loading device applied to a friction testing machine according to claim 6, wherein the tail end of the push rod of the elastic buffer mechanism is connected to the weight assembly end of the "L"-shaped lever through a connecting seat together.

Images