JPS62134540A - Heat fatigue tester - Google Patents

Abstract

PURPOSE:To make it possible to perform the measurement of fatigue characteristics conforming to an actual use stage, by a method wherein a test piece held so as to be movable to horizontal and vertical directions is moved to a heating part, a cooling part and a bending testing part to apply heat stress or dynamic stress to the test piece. CONSTITUTION:A heating part 30 is a heating oven 32 receiving the test piece 1 held by a holder 20 and has a proper heating means corresponding to heating temp. or a temp. rising speed. A cooling part 40 is constituted of a cooling chamber 42 receiving the test piece 1 held by the holder and a spray nozzle 44 protruded into said cooling chamber 42 and spraying a cooling medium to the test piece 1. A bending test part 50 is arranged at a position at a right angle, that is, horizontal to a base frame 10 above the cooling part 40 and loaded with a wt. 71 capable of applying the same or different load to the test piece 1 to make it possible to apply static load and there is no pulsation and accurate load can be applied to the test piece.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a thermal fatigue testing machine, and more specifically, it is a thermal fatigue tester that combines thermal stress and bending stress that a material receives in practical use into a test piece. The present invention relates to a thermal fatigue testing machine whose purpose is to apply a thermal fatigue cycle that closely approximates a practical load to a test piece, thereby making it possible to prepare a practical RQJ.

[Prior Art] Generally, many materials such as metals, alloys, and ceramics are used in complex rings of thermal stress and mechanical stress, but when they are used, it is necessary to evaluate their durability through thermal fatigue tests. has been done.

For this reason, in the past, testing machines that generally prepare a single test piece and repeatedly apply a predetermined mechanical stress, such as rotation, vibration, torsion, shearing, or bending, continuously or intermittently, or Testing machines and the like that apply the voltage in a heated atmosphere inside a furnace are used.

[Problems to be solved by the invention] However, conventional testing machines merely obtain data for comparing the mechanical fatigue properties of materials at room temperature or high temperature; The method without repeated quenching only provided data for conventional comparison of thermal damage resistance.

However, many metals, alloys, ceramics, etc.
JFl is generally used in stress fields where thermal stress (residual stress due to thermal cycles of heating and cooling) and mechanical stress (loaded stress due to load) are repeatedly applied simultaneously or alternately. Measuring fatigue properties according to the actual conditions of use is essential for predicting the Q i@ of a material in advance. Therefore, there is currently a demand for the development of a testing machine that can perform thermal fatigue tests in accordance with these usage conditions.

[Means for Solving the Problems] This invention was made in view of the above circumstances, and as a means for solving the above technical problems, it is a method of repeatedly subjecting a test piece to a predetermined thermal stress and mechanical direction. It is an object of the present invention to provide a thermal fatigue testing machine characterized by being able to measure fatigue properties in accordance with the actual usage of a test piece as a material by applying an arbitrary amount of heat until it finally breaks down. It is something.

That is, the present invention includes a heating section and a cooling section installed below a base frame from which a holder for holding a test piece hangs movably in horizontal and vertical directions, and a bending test section above the cooling section. and selectively move the test piece held by the holder to the heating section, cooling section, and bending test section to apply predetermined thermal stress and mechanical stress to the test piece. The present invention aims to provide a thermal fatigue testing machine characterized by the following features.

In the present invention, the cooling unit includes a cooling chamber that accommodates a holder that holds the test piece, and a spray nozzle that projects into the cooling chamber and sprays a cooling medium such as water onto the test piece. The bending test section is disposed in a horizontal position above the cooling section, and is composed of a forked support piece and a load application piece that can move forward and backward with respect to the test piece. Further, the holder includes a holder main body having an opening into which the test piece is inserted, and a supporting piece and a load applying piece. It consists of four through holes drilled at intervals, respectively, and a holding pin that is fitted into each of the through holes to hold the test piece and serve as a load fulcrum. In this case, the number of openings may be one, but when testing multiple test pieces at the same time, it is preferable to use a holder with multiple openings corresponding to the test pieces. The load application pieces are set in stages.

1 action” The above technical means works as follows.

A test piece held by a horizontally and vertically movable holder is moved to a heating section, a cooling section, and a bending test section, and the test piece is subjected to thermal stress or mechanical stress such as heating, cooling, and bending loads. By repeatedly or arbitrarily applying , it is possible to measure the fatigue properties in accordance with the actual usage of the material of the test piece.

[Example] Examples of the present invention will be described in detail below based on the drawings.

@Figure 1 shows a schematic front view of the thermal fatigue testing machine of the present invention,
2 and 3 show a side view and an enlarged plan view of FIG. 1, respectively, and the thermal fatigue testing machine of the present invention relates to a testing machine used, for example, to measure the fatigue characteristics of ceramics. , which relates to the case where three specimens are tested at the same time. It goes without saying that the design of related parts will need to be changed in response to an increase or decrease in the number of test pieces.

The testing machine of this invention has a base frame 1 formed in a gate shape.
Holder 2 for test piece 1 that can be hung horizontally and vertically at 0
0, a heating section 30 and a cooling section 40 arranged in parallel below the base frame 10, and a bending test section 50 arranged above the cooling section 40.

In this case, a horizontal guide shaft 12 is installed on the horizontal upper part of the base frame 10, and the horizontal guide shaft 12 is moved by a drive device 19 such as an electric motor or an air cylinder (the air cylinder is not shown in the drawing). A vertical movement motor 16 is attached via a slider 14 so as to be horizontally movable. Further, a vertical movement @ 1115 having a rack part 13 that meshes with the pinion 11 attached to the drive shaft 18 of the vertical movement motor 16 is attached to the base frame 10 so as to be vertically movable, and this vertical column @ 8
The holder 20 is connected to the lower end of the holder 115 via the connecting rod 17.
is installed.

Note that the test piece 1 is manufactured in a rectangular shape according to the standard test method, for example, in the case of a ceramic test piece, according to the JIS R1601 standard, but in the case of a metal test piece 1, it can be made into a round bar.

As shown in FIGS. 6 to 8, the holder 20 includes:
A holder main body having three openings 22 into which the test piece 1 is inserted centrally and into which the support piece 52 and load application piece 54 of the bending test section 50 to be described later are inserted from the left and right, and a screw hole 24 for connection of the connection rod 17. 26 and this holder body 26
Four L" through holes 28 (specifically, two sets of through holes 28a) are perpendicular to the frontage direction of the old translation frontage 22 in the middle part of and 28b), and each of the through holes 28
It is comprised of a holding pin 21 that is inserted into the holding pin 21 and holds the test piece 1. The holder 20 and the connecting rod 17 constructed in this manner are made of materials such as heat-resistant steel such as SUH3 or ceramics that can withstand high temperatures, depending on the test conditions. Further, cooling fins 17a are provided on three sides of the connecting rod 17 that do not contact the rack portion 13 for advantageous cooling (see FIG. 9).

The heating section 30 is connected to the holder 2 as shown in FIG.
The test piece is composed of an electric furnace in which a heater 34 is disposed within a heating furnace 32 that accommodates a test piece 1 held by a wire. Note that the heating section 30 does not necessarily need to be an electric furnace, and may be a furnace or the like having other heating means such as electromagnetic induction heating, depending on the heating temperature and temperature increase rate.

The cooling unit 40 also includes a cooling chamber 42 that accommodates the test piece 1 held by the holder 20, and a cooling chamber 42 that accommodates the test piece 1 held by the holder 20.
2 and a spray nozzle 44 that projects into the test piece 1 and sprays a cooling medium such as water, high-pressure air, liquid nitrogen, etc. onto the test piece 1. In addition, when using water as a cooling medium,
The spray nozzle 44 is connected to the tank 46 via a connecting pipe 48 in order to spray water stored in a tank 46 disposed below the cooling chamber 42 , and is also connected to an air pipe 49 . The spray height can be freely adjusted by means of the provided control valve 41. Therefore, any cooling acceleration of the test piece 1 can be obtained. Furthermore, by spraying cooling water onto the test piece 1 in this manner, the cooling rate can be increased.

On the other hand, as shown in FIG. 4 and FIG. It is composed of three forked support pieces 52 (specifically, 52a, 52b, 52C) and a load application piece 54 (specifically, 54a, 54b, 54c) that can move forward and backward with respect to each other. Each of the support pieces 52 is connected to the support piece fixing portion 5
It is supported by a link device 56 using a trouble joint mechanism connected at 2 degrees, and can move forward and backward relative to the test piece 1 via a rail 72 by operating an air cylinder 56a. Further, each load application piece 54 is provided symmetrically with the same number of support pieces 52, and each bearing 58
Keep it slidable by 1. A pin 53 and a long hole 55 are attached to the other end of the sliding shaft 51.
The reciprocating mechanism 60 is connected to the swinging arm 57 for applying a cart through the swinging arm 57, and can move forward and backward relative to the test piece 1. Note that in this case, the swing arm 57 is connected to each opening 22 of the holder 20.
The swing arms 57 are arranged in three stages corresponding to the above, and each swing arm 57 is pivotally supported by the base frame 10 with the same support shaft 59, so that it can move one degree in the horizontal direction. In addition, the swing arm 5
A predetermined load (3
The same or different loads can be applied to each test piece 1.

) is loaded (see FIGS. 1 and 2). The reciprocating mechanism 60 includes a drive motor 61 with a reduction gear that can rotate forward and reverse, and a transmission gear 6.
A rotating threaded barrel 66 is integrally attached to a driven gear 65 that receives rotation from a drive gear 64 attached to a drive shaft 63 of a drive motor 61 via a rotary threaded barrel 66, and a screw is coupled to the rotating threaded barrel 66 in a penetrating manner. A connecting base 6 is attached to the tip of the screw shaft 67.
8 slides on the rail 72° according to the reciprocating movement of the screw shaft 67, and the swing arm 57 is locked by the load of the weight 71 to the locking rod 69 that stands up on the connecting table 68. has been done. Therefore, by reciprocating the screw shaft 67 by the forward and reverse rotation of the drives 1 and 61 of the reciprocating mechanism 60, the connecting table 68 moves on the rail 72'.
The load application piece 54 is applied to the test piece 1 via the swing arm 57.
It is designed to move forward and backward.

According to the bending test section 50 configured in this way, a static load can be applied to the test piece 1, and there is no pulsation unlike the conventional load application method using a hydraulic load type such as a hydraulic cylinder. , it is possible to accurately apply a load to the test piece 1. In this case, a dynamic load can also be applied by increasing the rotation speed of the drive motor 61.

The case of measuring the fatigue characteristics of the test piece 1 using the thermal fatigue tester of the present invention configured as described above will be explained with reference to the control circuit diagram shown in FIG. Prepare a ceramic test piece (refer to JIS R1601 standard) of the same dimensions, insert the holding pin 28a into each opening 22 of the above-mentioned holder 20 attached to the cellar 1, hold it with the holding pin 28b, and then move the connecting rod 17 along the vertical movement axis. Assemble to 15 (
In this case, the test piece 1 is held with some play. )
Then, the holder 20 is moved into the heating section 30 manually or by the cylinder 19 and the vertical movement motor 1G and heated to a predetermined temperature, and then the holder 20 is moved to the cooling section 40 and rapidly cooled by the spray nozzle 44. . next,
The cooled test piece 1 is moved to the bending test section 50, and the same test is carried out for each test piece 1 while the support piece 52 and load application piece 54 of the bending test section 50 are in contact with each other toward the test piece 1. −
Or perform a bending strength test by applying different loads.

In this case, the link device 56 is made 1III and the support piece 5
2 is inserted into the opening 22 and the test piece 1 is held between it and the support pin 28a, and then the load application piece 54 is advanced to abut the test piece 1 and apply a predetermined load. If the test piece 1 cannot withstand the applied load, the test piece 1 will break from the center, and the broken test piece 1 will be prevented from detaching from the boulder 20 by the holding pin 28b.

On the other hand, the forward movement of the load application piece 54 beyond a certain level is prevented by the 1z movable arm 57 coming into contact with the locking rod 69 again. Similarly, the fatigue properties are investigated by repeatedly conducting heating, cooling, and bending tests to finally reach failure. The number of repetitions in this case is counted by a counter 77. Note that when the test piece 1 is destroyed, the load applying piece 54 moves forward and the weight 71 falls downward. is sent to the program sequencer 75, and the program sequencer 75 sends a signal to the counter 77 to stop further counting. If all three test pieces 1 are destroyed, a signal is sent to each drive unit and the holder 20
The movement of the bending test device 50 and the driving of the bending test device 50 are stopped.

In the above test, we explained the case in which the test piece 1 is repeatedly heated, cooled, and bent in the order of heating, cooling, and bending. However, it is not necessary to perform the test in this order. Stress and mechanical stress may be applied.

Furthermore, although the above embodiment describes the case of a thermal fatigue test of ceramics, the test piece 1 is not necessarily limited to ceramics, and the thermal fatigue test can be similarly performed on metals and alloys. Depending on the material, the cooling medium may be something other than water, for example, liquid nitrogen.Also, a strain gauge may be attached to the drive shaft 51 to measure the reaction force applied to the above-mentioned circumferential movement 'r (It 51). Strength can also be measured.

``Effects of the Invention As explained above, according to the thermal fatigue testing machine of the present invention, a plurality of test pieces held by a horizontally and vertically movable holder can be heated, cooled, and folded. Since it can be automatically moved to the bending test section at will, it is possible to repeatedly or arbitrarily apply thermal stress such as heating and cooling to the test piece and mechanical stress such as bending load, as well as to test the material. Its utility value is obvious, as it provides excellent effects such as being able to accurately measure fatigue characteristics in line with actual usage conditions.

[Brief explanation of drawings]

Figure 1 is a schematic front view of the thermal fatigue testing machine of the present invention, Figure 2 is a side view of Figure 1, Figure 3 is an enlarged plan view of Figure 1, and Figure 4 is an enlarged plan view of Figure 1.
5 is a plan view of FIG. 4, FIG. 6 is a perspective view of the holder in this invention, and FIG. 8 is a sectional view taken along ■-■ of FIG. 6, FIG. 9 is a front view of the connecting rod in this invention, and FIG. The best thermal fatigue testing machine! 3
0 circuit diagram. Description of symbols (10)...Base frame (12)...Horizontal guide shaft (14)...Slider (16)...Vertical movement motor (19)...Cylinder (20)...Holder (21)...Holding pin (22)...Opening (26)...Holder body (28)...Through hole (30)...Heating part (40)...Cooling part (42) ... Cooling chamber (44) ... Spray nozzle (50) ... Bending test section (52) ... Support piece (54) ... Load application piece (56) ... Link device (60 )...Reciprocating motion R groove (10)...Wire (11)...Weight patent Applicant: Nippon Light Kinfu Co., Ltd. Patent
Applicant: Akira Niihara - Agent
People Patent Attorney Satoshi Nakamura FfIi (External 2
Name) 10, Base frame 19 Nishisonta" 20:, L 3o: Force 0 Rudder sound P 40"; Minute B'Iro 42 Cooling 1 71 Weight 21, Holding bit 7 Fig. 8 Fig. 9B No. 9 figure

Claims (4)

[Claims] (1) A heating section and a cooling section are installed below the base frame from which the holder that holds the test piece hangs so as to be movable in horizontal and vertical directions, and a bending test section is installed above the cooling section. , the test piece held by the holder is selectively moved to the heating section, the cooling section and the bending test section to apply predetermined thermal stress and mechanical stress to the test piece. Features of thermal fatigue testing machine. (2) Claims that include that the cooling unit is comprised of a cooling chamber that accommodates a holder that holds a test piece, and a spray nozzle that projects into the cooling chamber and sprays a cooling medium onto the test piece. The thermal fatigue tester according to item 1. (3) The bending test section is arranged in a horizontal position above the cooling section, and also includes a forked support piece and a load application piece that can move forward and backward, and are arranged in symmetrical positions with respect to the test piece. A thermal fatigue testing machine according to claim 1, comprising: (4) The holder includes a holder main body having an opening into which a test piece is inserted as well as a support piece and a load application piece, and a holder body that is perpendicular to the opening direction of the opening in the middle part of the holder main body and symmetrical with respect to the test piece. Claim 1 comprising: four through holes drilled at intervals from each other; and a holding pin fitted into each of the through holes to hold the test piece. Thermal fatigue tester described.