JPS648780B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spring fatigue durability test device.

Conventionally, as the above test device, a spring sample is interposed between a fixed table and a vibration table facing the fixed table, and the vibration table is vibrated, and the spring sample is vibrated several million times. This test tests the fatigue of the sample.

However, according to the above-mentioned conventional fatigue durability test device, the rotational force of a motor is configured using a mechanism such as a cam or a gear as a vibration generator that applies vibration to the vibration table, and a movable body that holds the vibration table is configured to generate rotational force of a motor. A mechanism that provides reciprocating motion to the motor is known, but such a mechanism that mechanically converts the rotation of the motor into reciprocating motion requires a complicated structure and requires an extremely large driving force from the motor.

An object of the present invention is to use an electromagnetic vibration generator capable of generating vibrations by electromagnetic force as a vibration generator to configure a spring fatigue durability test apparatus to eliminate the above-mentioned drawbacks. explain.

1 to 5 are simplified configuration diagrams and circuit diagrams showing an embodiment of a spring fatigue durability test device according to the present invention. In the figures, 1 is an electromagnetic vibration generator, which is connected to an excitation coil and a drive. This device applies vibration to a movable body, which will be described later, by supplying an alternating current to an electromagnetic coil consisting of a coil, and a base body 3 made of a magnetic material is attached to the lower side of a case 2 that constitutes this device 1. This base body 3 is installed on the floor side via a base 3a, and an excitation coil is arranged on the upper side of this base body 3, and yokes 5a, b are fixed to the outside of this excitation coil 4. A drive coil 7 fixed to the lower end side of the movable body 6 faces inside the yoke 5a, and a magnetic circuit S generated by the excitation coil 4 and the drive coil 7 is connected to the coils 7, 4, the base body 3, the yoke 5b, and the yoke. is formed by a loop through 5a. Note that input is supplied to the coil 7 via a lead wire 9.
The movable body 6 is always able to vibrate in the vertical direction by rollers 8, and this movable body 6 is made of a cylindrical body extending upward, and its upper side is formed at the center of the lower spring presser table 12. rectangular hole 6s
It extends through the center to the lower surface of the vibration table 10 and is fixed to the lower surface of the vibration table 10. The vibration table 10 has a substantially square shape as shown in FIG. 2, and has recesses 11 on opposite sides thereof.
A fixing base 14 fixed to a side shaft 13 extending upward from the base 3 is located in the recess 11. Note that the side shaft 13
passes through the lower spring holding table 12 and the upper spring holding table 20 via sliding bearings 21 attached to these tables, and a spring sample holding screw is installed in the center of the fixing base 14 fixed to the side shaft 13. 15 is pivotally mounted, both ends of this screw 15 are threaded in opposite directions, and one threaded portion is connected to the threaded portion 1 of the upper spring holding table 20.
9, and the other threaded part is threaded into the threaded part 18 of the lower spring holding table 12, and this screw 15
This screw 15 can be rotated by rotating a rubber gear 17 that is screwed into a cap gear 16 provided on the upper end side, and thereby the adjusting mechanism G
and table 1 with this adjusting mechanism G.
2 and 20 can be brought closer to each other or separated from each other. As shown in FIG. 4, a presser plate 31 is provided between the vibrating table 10 and the lower spring presser table 12 and between the vibrating table 10 and the upper spring presser table 20, and is held movably up and down by a shaft 30. , 31, a cartridge C having a plurality of coiled spring samples 32 interposed therebetween is disposed. Note that the cartridges C have different sizes on the tables 10, 12, and 20.
It is installed in a well-balanced manner on the outside of the

The above excitation coil 4 and drive coil 7 are provided with an oscillator 3.
The output from the oscillator 33 is supplied via a displacement controller 34 and an amplifier 35, and the output of the oscillator 33 is supplied to a counter 37. When the number of oscillation frequencies counted by the counter 37 reaches a set value,
A stop signal ST is sent to the amplifier 35, and the inputs to the coils 4 and 7 are cut off. Further, the vibration table 10 is provided with a sensor 36 that detects the amount of vertical displacement of the table 10.
The output of 6 is sent to the displacement meter 37, and this displacement meter 37
Then, the displacement controller 34 is controlled so that the amount of displacement of the vibration table 10 becomes a predetermined value. That is, by adjusting the vertical position of the output Q of the oscillator 33 with respect to the 0 level M as shown in FIG.
The center position of the vibrating table 10 is adjusted up and down in accordance with the above. In this case oscillator 3
The vibration period of the output Q of No. 3 is set so as to obtain a resonance state determined by the spring constant of the spring 32 and the mass of the vibrating portion of the electromagnetic vibration generator 1. Note that 50 and 51 are air cooling ducts.

In the above configuration, when the oscillator 33 is operated and the alternating output Q is supplied to the coils 4 and 7, an electromagnetic force is generated by the drive coil 7 and the excitation coil 4, so that vibrations are generated in the movable body 6. This frequency corresponds to the frequency of the output Q of the oscillator 33. The vibration of the movable body 6 generates vertical vibrations in the vibration table 10 held by the movable body 6, and as a result, as shown in FIG. , the spring sample 32 oscillates by a set number of vibrations, thereby allowing fatigue of the sample to be detected.

Therefore, according to this embodiment, after rotating the gear 17 to rotate the screw 15 and moving the upper spring presser table 20 and the lower spring presser table 12 away from the vibration table 10, the vibration table 10 and The cassette C is placed in a well-balanced manner between the lower spring retainer table 12 and between the vibration table 10 and the upper spring retainer table 20, and the gear 17 is rotated in the opposite direction to rotate the upper spring retainer table 20 and the lower spring retainer table 12. is moved close to the vibration table 10 and tightened until the set length (amplitude center) of the sample 32 is reached.Then, the electromagnetic vibration generator 1 is driven to give vibration.At this time, the vibration period of the sample is adjusted by adjusting the sample's spring constant and It is controlled to a specific frequency that achieves a resonance state determined by the mass of the vibrating part of the device 1.As a result, the springs placed above and below are driven by the repulsive force of each other, and the device It is possible to reduce the driving energy of the electromagnetic vibration generator 1 by operating the counter when the set frequency is reached.
Since the device 1 automatically stops, the reset operation of the device 1 can be performed unattended.

As explained above, according to the present invention, the upper end of the movable body of an electromagnetic vibration generator having an electromagnetic coil that transmits vibrations in the vertical direction to the movable body that extends in the vertical direction and is held so as to be movable in the vertical direction. To,
A horizontally extending vibration table is fixed, and horizontally extending spring holding tables are provided on the upper and lower sides of this vibration table, and the movable body is extended upward via the lower spring holding table, and the vibration table is fixed. A spring sample is placed between the table and the spring holding table, and the vibration table is vibrated up and down based on the electromagnetic force of the electromagnetic vibration generator, and fixed stands are provided on both sides of the vibration table. The fixed table is equipped with an adjusting mechanism that adjusts the above spring holding tables so that the upper and lower spring holding tables approach or separate from the vibration table, so the vibration table can be mechanically driven using a motor as in the conventional method. Unlike conventional devices, the drive energy can be reduced, the structure is simple and failures are less likely to occur, the cost is lower, unnecessary vibrations of the device itself can be suppressed, the service life can be extended, and the The idea of providing a spring holder table allows testing twice as many spring samples as usual, and since the repulsive force of one spring sample acts as a compressive force on the other spring sample, the driving energy is transferred to the spring holder table. It is almost the same as the one provided only on one side of the vibrating table, and the above-mentioned adjust mechanism allows the upper and lower spring presser tables to be adjusted at once with respect to the vibrating table, making it possible to easily and accurately set a large number of spring samples. .

[Brief explanation of drawings]

1, 2, and 3 are a side view, an AA sectional view, and a BB sectional view showing an embodiment of the spring fatigue durability test device according to the present invention, and FIG.
The figure shows an example of a cassette for holding a spring sample.
The figure is a waveform diagram for explaining the operation of the electric circuit diagram. 1... Electromagnetic vibration generator, 2... Case, 3...
... Base body, 4 ... Excitation coil, 5a, 5b ... Yoke, 6 ... Movable body, 7 ... Drive coil, 8 ... Roller, 10 ... Vibration table, 12 ... Lower spring holding table, 13 ... Side shaft, 15...sample holding screw, 17...gear, 18, 19...screw,
20... Upper spring presser table.

Claims (1)

[Claims] 1. A horizontally extending vibration table is fixed to the upper end of the movable body of an electromagnetic vibration generator having an electromagnetic coil that transmits vibrations in the vertical direction to a movable body that extends vertically and is held movably in the vertical direction. Spring presser tables extending horizontally are provided on the upper and lower sides of this vibration table, and the movable body extends upward through the spring presser table on the lower side, and is connected between the vibration table and the spring presser table. A spring sample is placed on the vibration table, and the vibration table is vibrated up and down based on the electromagnetic force of the electromagnetic vibration generator.Fixed stands are provided on both sides of the vibration table. A fatigue durability testing device for a spring, which is provided with an adjusting mechanism for adjusting each of the above-mentioned spring holding tables so that the upper and lower spring holding tables approach or separate from each other.