A device and method for detecting the bending strength of a die steel

Abstract

The application provides a die steel bending strength detection device and detection method, which comprises a rack, a pressure head piece, a support frame and a positioning mechanism, the pressure head piece is arranged on the upper part of the rack, the pressure head piece moves along the vertical direction, two groups of support frames are arranged on the rack and are symmetrically distributed along the pressure head piece left and right, a support roller is rotationally connected to the top end of the support frame, a placing groove is formed in the circumferential top of the support roller along the axial direction, and the bottom end of the placing groove is provided with a plane contact surface, the plane contact surface of the placing groove arranged on the support roller enables the die steel sample to keep face contact with the support roller during the bending process, effectively solves the problem of local stress concentration caused by the line contact between the existing cylindrical support roller and the sample, avoids the generation of local indentation and micro cracks at the support point, ensures the authenticity of the test results, and improves the accuracy of the die steel bending strength detection.

Description

Technical Field

[0001] This invention relates to the field of mold steel testing technology, and in particular to a device and method for testing the bending strength of mold steel. Background Technology

[0002] Die steel is an important material for manufacturing molds such as cold stamping dies, hot forging dies, and die casting molds. Its mechanical properties directly affect the service life and processing quality of the molds. Bending strength is one of the important mechanical properties of die steel, reflecting its resistance to bending loads. The hardness of die steel is usually between HRC40 and 65. It has extremely high compressive strength and wear resistance, and is widely used in automobile manufacturing, aerospace, and electronic communications.

[0003] Bending strength testing is an important method for evaluating the mechanical properties of mold steel. It is typically performed using a three-point bending test. Existing bending strength testing devices usually include a frame, a pressure head, and two support rollers. The pressure head is located above and between the two support rollers, applying a bending load to the sample placed on the support rollers. However, existing testing devices have the following shortcomings: Conventional cylindrical support rollers have line contact with the sample, resulting in a small contact area and extremely high contact stress. During loading, local indentations or even microcracks are easily generated at the support points. This not only alters the stress state of the sample but may also cause premature cracking at the support points, causing the fracture location to deviate from the mid-span region, affecting the accuracy of the test results. For mold steels with hardness as high as HRC40-65, the problem of local stress concentration caused by line contact is particularly prominent, and in severe cases, it can lead to distorted test data, failing to accurately reflect the true bending strength of the mold steel. Furthermore, existing testing devices require manual and repeated adjustments of the sample position to ensure it is located at the symmetrical center of the support rollers and that the span meets standard requirements, making the operation cumbersome and inefficient. In view of this, the applicant proposes a device and method for testing the bending strength of mold steel to improve the above-mentioned problems. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a device and method for testing the bending strength of mold steel. This invention addresses the problems of existing devices for testing the bending strength of mold steel that use cylindrical support rollers, which have line contact with the sample, resulting in high contact stress and easy formation of local indentations or even microcracks. Furthermore, the device requires repeated adjustments to the sample position during placement.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A mold steel bending strength testing device is used to test the bending strength of mold steel samples. The mold steel bending strength testing device includes a frame, a pressure head, a support frame, and a positioning mechanism. The pressure head is disposed on the upper part of the frame, and the pressure head moves in the vertical direction; The support frame is provided on the machine frame in two sets and is symmetrically distributed on the left and right sides of the pressure head. The top of the support frame is rotatably connected to the support roller. The top of the support roller is provided with a placement groove along the axial direction. The bottom end of the placement groove is set as a planar contact surface. Both ends of the support roller extend to the outside of the support frame and are installed with a reset component between them and the support frame. In the initial state, the reset component is not activated, and the mold steel sample is placed in the placement grooves of the two support rollers, with surface contact between the sample and the planar contact surface of the placement groove. The positioning mechanism includes a positioning baffle, which is an L-shaped structure and is disposed on one side of one of the support frames. A longitudinal support assembly is installed between the positioning baffle and the frame. The longitudinal support assembly is used to drive the positioning baffle to move longitudinally. A linkage pressure rod is provided between the longitudinal support assembly and the pressure head. When the linkage pressure rod is not in contact with the longitudinal support assembly, the planar contact surfaces of the positioning baffle and the support roller are located on the same horizontal plane; When the linkage pressure rod comes into contact with the longitudinal support assembly, the positioning baffle moves downward along the longitudinal direction.

[0006] Preferably, the reset assembly includes a linkage component installed at the end of the support roller, and the reset assembly also includes an arc-shaped rod disposed on the outside of the support frame. Both ends of the arc-shaped rod are fixedly connected to the support frame, and a first reset spring is sleeved on the outside of the arc-shaped rod. One end of the linkage component is sleeved on the arc-shaped rod.

[0007] Preferably, the linkage includes an embedded block and a swing rod fixedly connected to the outer wall of the embedded block. The end of the swing rod away from the embedded block has a through hole. The swing rod is sleeved on the arc-shaped rod through the through hole. One end of the first return spring abuts against the outer wall of the swing rod. The end of the support roller has an embedded groove. The embedded block is inserted into the embedded groove and fixedly connected to the support roller by bolts.

[0008] Preferably, the lower circumference of the support roller is provided with an arc-shaped limiting groove along the axial direction, and a stop bar is fixedly connected inside the arc-shaped limiting groove of the support frame.

[0009] Preferably, the mold steel bending strength testing device further includes an adjustment mechanism for adjusting the distance between the two sets of support frames.

[0010] Preferably, the frame has an internal mounting cavity, and the adjustment mechanism includes two sliding seats disposed in the mounting cavity. The two support frames are respectively fixedly connected to the two sliding seats. A bidirectional lead screw is rotatably connected in the mounting cavity. The two sliding seats are respectively threaded to the two ends of the bidirectional lead screw with opposite directions of rotation. One end of the bidirectional lead screw extends to the outside of the frame and is fixedly connected to an adjusting handwheel. A guide rail is also fixedly connected to the bottom of the mounting cavity. The guide rail is arranged along the axial direction of the bidirectional lead screw, and the sliding seats slide in cooperation with the guide rail.

[0011] Preferably, the longitudinal support assembly includes a support base fixedly connected to the middle position of the frame, a pair of guide rods fixedly connected to the top of the support base, a connecting plate slidably connected to the pair of guide rods, the top end of the guide rods extending above the connecting plate and threaded with a limit nut, and a second return spring sleeved between the top of the support base and the bottom of the connecting plate and outside the guide rods. A telescopic sleeve is fixedly connected to one side of the connecting plate. A telescopic rod is slidably connected inside the telescopic sleeve. The telescopic rod has an L-shaped structure, and the end of the telescopic rod away from the telescopic sleeve is fixedly connected to the positioning baffle.

[0012] Preferably, a sliding sleeve is fixedly connected to the outer wall of the positioning baffle, the axis of the sliding sleeve is vertically arranged, a fixed sliding rod is slidably arranged inside the sliding sleeve, and the bottom end of the fixed sliding rod is fixedly connected to a support frame in a similar position.

[0013] Preferably, the linkage pressure rod includes a mounting sleeve fixedly sleeved on the pressure head component, and a pressure rod is fixedly connected to the outer wall of the mounting sleeve. The pressure rod has a multi-segment bending structure design, and the end of the pressure rod away from the mounting sleeve is located directly above the telescopic sleeve.

[0014] The present invention also provides a testing method for a mold steel bending strength testing device, comprising the following steps: S1. According to the size of the mold steel sample to be tested, rotate the adjusting handwheel to drive the bidirectional screw to rotate, which will drive the two sliding seats to move synchronously towards or away from each other along the guide rail, so that the two sets of support frames move synchronously with the sliding seats, and adjust the center distance between the two support rollers to the set support span. S2. Place the mold steel sample horizontally in the placement groove of the two support rollers, and push the sample to move along the axial direction of the support rollers so that the end face of the mold steel sample abuts against the vertical side wall of the positioning baffle, thus completing the axial centering and positioning of the mold steel sample. At this time, the bottom surface of the mold steel sample and the plane contact surface of the placement groove form a surface contact support. S3. Drive the pressure head component to descend at a constant speed in the vertical direction. When the pressure head component is close to the mold steel sample but has not yet contacted the mold steel sample, the linkage pressure rod component contacts the longitudinal support component, causing the positioning baffle to move down synchronously away from the mold steel sample. S4. The pressure head continues to descend and contacts the mid-span position of the mold steel specimen, applying a bending load to the mold steel specimen. The mold steel specimen gradually bends and deforms, and the mold steel specimen drives the support roller to rotate adaptively around its own axis. The flat contact surface of the groove is always in surface contact with the bottom surface of the mold steel specimen, effectively dispersing the contact stress at the support point. S5. After the test is completed, the driving pressure head returns to the vertical direction, the linkage pressure rod rises synchronously with the pressure head, the longitudinal support component drives the positioning baffle to move upward and reset to the initial positioning height, and the reset component drives the support roller to rotate and reset to the initial position.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: 1. This invention, through the planar contact surface of the placement groove on the support roller, ensures that the support roller maintains surface contact with the mold steel sample during bending, effectively solving the problem of local stress concentration caused by the line contact between the existing cylindrical support roller and the sample. It avoids local indentations and microcracks at the support point, ensuring the authenticity of the test results and improving the accuracy of mold steel bending strength testing. The reset component allows the support roller to automatically reset after the test, facilitating the next test operation and improving the continuity and efficiency of the test.

[0016] 2. The present invention uses a positioning baffle to position the mold steel sample when it is placed, avoiding repeated adjustments and improving testing efficiency. Through the linkage design of the longitudinal support component and the linkage pressure rod, the positioning baffle is automatically moved away from the sample when the pressure head moves down, avoiding interference with the bending test of the sample. This realizes the automation of positioning and avoidance, and further improves the testing efficiency. Attached Figure Description

[0017] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments of the invention and, together with the specification, further serve to explain the principles of the invention and enable those skilled in the art to practice and use the invention.

[0018] Figure 1 This is a schematic diagram of the overall three-dimensional first-view structure of the present invention; Figure 2 This is a schematic diagram of the overall three-dimensional second-view structure of the present invention; Figure 3 This is a schematic diagram of the frame, support frame, and adjustment mechanism of the present invention; Figure 4 This is a schematic diagram of the support frame and support roller structure of the present invention; Figure 5 for Figure 4 Enlarged schematic diagram of area A structure in the image; Figure 6 This is a schematic diagram of the linkage structure; Figure 7 This is a schematic diagram of the longitudinal cross-sectional structure of the support roller and the stop bar; Figure 8 This is a schematic diagram of the three-dimensional structure of the positioning mechanism; Figure 9 This is a top view of the positioning mechanism. Figure 10 This is a schematic diagram of the linkage pressure bar structure.

[0019] [Figure Labels] 1. Rack; 2. Support frame; 210. Support roller; 211. Placement groove; 212. Arc-shaped limiting groove; 220. Linkage component; 221. Embedded block; 222. Swing rod; 223. Through hole; 230. Arc-shaped rod; 240. Connecting plate; 250. First return spring; 260. Stop bar; 3. Adjustment mechanism; 310. Sliding seat; 320. Two-way lead screw; 330. Adjustment handwheel; 340. Guide rail; 4. Press head components; 5. Positioning mechanism; 510. Positioning baffle; 520. Telescopic rod; 530. Telescopic sleeve; 540. Fixed slide rod; 541. Sliding sleeve; 550. Support base; 560. Guide rod; 570. Connecting plate; 580. Second return spring; 590. Linkage pressure rod; 591. Mounting sleeve; 592. Pressing rod; 6. Mold steel sample.

[0020] As shown in the figure, specific structures and devices are marked in the figure to clearly illustrate the structure of the embodiments of the present invention. However, this is only for illustrative purposes and is not intended to limit the present invention to this specific structure, device and environment. Those skilled in the art can adjust or modify these devices and environments according to specific needs. Detailed Implementation

[0021] The following is a detailed description of a double-sided pressing fixture for a flat frame speaker mesh foam provided by the present invention, with reference to the accompanying drawings and specific embodiments. It should be noted that, to make the embodiments more detailed, the following embodiments are the best and preferred embodiments; those skilled in the art can also use other alternative methods to implement some known technologies; and the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0022] It should be noted that the use of terms such as "an embodiment," "an embodiment," "an exemplary embodiment," and "some embodiments" in the specification indicates that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments (whether explicitly described or not) should be within the knowledge of those skilled in the art.

[0023] Generally, terms can be understood at least partly from their use in context. For example, depending at least partly on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in a singular sense, or a combination of features, structures, or characteristics in a plural sense. Additionally, the term "based on" can be understood not necessarily to convey an exclusive set of factors, but rather, alternatively, depending at least partly on the context, to allow for the presence of other factors that are not necessarily explicitly described.

[0024] It is understood that the meanings of “on”, “above”, and “above” in this invention should be interpreted in the broadest manner, such that “on” means not only “directly on” something, but also includes the meaning of being “on” something with an intervening feature or layer, and that “above” or “above” means not only “on” something, but also includes the meaning of being “on” something without an intervening feature or layer.

[0025] Furthermore, spatially related terms such as “below,” “under,” “lower,” “above,” and “upper” are used herein for convenience to describe the relationship of one element or feature to one or more other elements or features, as illustrated in the accompanying drawings. Spatially related terms are intended to cover different orientations in the use or operation of the device other than those depicted in the accompanying drawings. The device may be oriented in other ways, and the spatially related descriptive terms used herein can be interpreted similarly.

[0026] like Figures 1 to 10As shown, an embodiment of the present invention provides a mold steel bending strength testing device for testing the bending strength of a mold steel sample 6. The mold steel bending strength testing device includes a frame 1, a pressure head 4, and a support frame 2. The pressure head 4 is disposed on the upper part of the frame 1 and moves in the vertical direction. The support frame 2 is located on the frame 1 and is provided in two sets, which are symmetrically distributed on the left and right sides of the pressure head 4. The top of the support frame 2 is rotatably connected to a support roller 210. The top of the support roller 210 is provided with a placement groove 211 along the axial direction. The bottom end of the placement groove 211 is a planar contact surface. Both ends of the support roller 210 extend to the outside of the support frame 2 and are installed with a reset component between them and the support frame 2. In the initial state, the reset component is not activated. The mold steel sample 6 is placed in the placement groove 211 of the two support rollers 210 and is in surface contact with the planar contact surface of the placement groove 211. The frame 1 is made of high-strength steel, possessing sufficient rigidity and stability to withstand the load during the testing process. The pressure head 4 is used to apply bending load to the mold steel sample. The pressure head 2 moves vertically and can be driven by a hydraulic system, electric push rod, or mechanical transmission. The support frame 2 supports the support roller 210. Two sets of support frames 2 are symmetrically distributed on the left and right sides of the pressure head 2 to ensure uniform force on the sample. The support roller 210 is rotatably connected to the support frame 2 and can rotate with the sample during bending. The planar contact surface on the placement groove 211 is used to contact the bottom surface of the mold steel sample, so that the support roller 210 always maintains surface contact with the sample during bending. This effectively solves the problem of local stress concentration caused by the line contact between the existing cylindrical support roller and the sample, avoids local indentations and microcracks at the support point, ensures the authenticity of the test results, improves the accuracy of mold steel bending strength testing, and avoids the generation of local indentations and microcracks. The reset component is used to automatically reset the support roller after the test is completed, facilitating the next operation.

[0027] In some preferred embodiments of this application, the width of the planar contact surface of the groove 211 is 1.4 to 1.7 times the width of the mold steel sample, and the depth of the groove 211 is 0.3 to 0.5 times the thickness of the mold steel sample. This serves both to position and limit the sample, preventing lateral displacement during testing, and to avoid uneven stress distribution caused by an excessively deep groove. In specific implementations, the appropriate width of the planar contact surface and the depth of the groove 211 can be selected according to the specifications and dimensions of the mold steel sample.

[0028] By adopting the above technical solution and rationally designing the width and depth of the planar contact surface of the groove, surface contact between the sample and the support roller is achieved, reducing contact stress, while also ensuring the positioning and limiting effect of the sample, thus improving the accuracy and repeatability of the test. In this embodiment, as Figure 5As shown, the reset assembly includes a linkage 220 installed at the end of the support roller 210. The reset assembly also includes an arc-shaped rod 230 disposed on the outside of the support frame 2. Both ends of the arc-shaped rod 230 are fixedly connected to the support frame 2 with connecting plates 240. The connecting plates 240 and the arc-shaped rod 230 can be welded and fixed. The connecting plates 240 and the support frame 2 are fixedly connected by bolts. A first reset spring 250 is sleeved on the outside of the arc-shaped rod 230. One end of the linkage 220 is sleeved on the arc-shaped rod 230. The linkage 220 is fixedly installed at the end of the support roller 210 and rotates synchronously with the support roller 210. The curvature of the arc-shaped rod 230 matches the rotation trajectory of the support roller 210. The first return spring 250 is sleeved on the outside of the arc-shaped rod 230, with one end pressing against the linkage 220 and the other end pressing against the connecting plate 240. When the support roller 210 rotates during the bending of the sample, the linkage 220 rotates with the support roller 210 and compresses the first return spring 250. After the test is completed, the first return spring 250 releases its elastic force, driving the linkage 220 to rotate in the opposite direction, so that the support roller 210 automatically returns to its initial position without manual adjustment, which facilitates the next test operation and improves the continuity and efficiency of the test. The design of the arc-shaped rod 230 provides a stable motion track for the linkage 220, ensuring the smoothness and reliability of the reset process.

[0029] In a preferred embodiment of this example, such as Figure 6 As shown, the linkage 220 includes an embedded block 221 and a swing rod 222 fixedly connected to the outer wall of the embedded block 221. The end of the swing rod 222 away from the embedded block 221 has a through hole 223. The swing rod 222 is sleeved on the arc-shaped rod 230 through the through hole 223. One end of the first return spring 250 presses against the outer wall of the swing rod 222. The end of the support roller 210 has an embedded groove. The embedded block 221 is inserted into the embedded groove and fixedly connected to the support roller 210 by bolts. To ensure a firm and reliable connection between the linkage 220 and the support roller 210, the embedded block 221 is inserted into the embedded groove at the end of the support roller 210. In this embodiment, the cross-section of the embedded block 221 is a polygonal structure, and the embedded groove is also a matching polygonal structure, which improves the assembly stability. The swing rod 222 and the embedded block 221 are integrally cast to improve the structural strength. This structural design enables the linkage 220 to swing along the arc rod 230. One end of the first return spring 250 presses against the outer wall of the swing rod 222 to provide a return force for the swing rod 222.

[0030] In this embodiment, as Figure 7As shown, an arc-shaped limiting groove 212 is axially formed at the lower circumference of the support roller 210. Both ends of the arc-shaped limiting groove 212 extend through the ends of the support roller 210. A stop rod 260 is fixedly connected inside the support frame 2 within the arc-shaped limiting groove 212. The curvature range of the arc-shaped limiting groove 212 matches the rotation range of the support roller 210. The stop rod 260 is fixedly connected inside the support frame 2 and extends into the arc-shaped limiting groove 212 to limit the rotation range of the support roller 210. When the support roller 210 rotates back to its original position under the action of the reset assembly, the stop rod 260 contacts the end of the arc-shaped limiting groove 212, preventing the support roller 210 from continuing to rotate. This prevents excessive rotation of the support roller 210 from causing the placement groove 211 to deviate from its correct position, ensuring the accuracy and repeatability of the detection.

[0031] In this embodiment, as Figure 3 As shown, the mold steel bending strength testing device also includes an adjustment mechanism 3. The adjustment mechanism 3 is used to adjust the distance between the two sets of support frames 2. By adjusting the distance between the two sets of support frames 2, the span of the mold steel sample can be changed, thereby adapting to the testing requirements of mold steel samples of different specifications and sizes. The frame 1 has an installation cavity inside. The adjustment mechanism 3 includes two sliding seats 310 set in the installation cavity. The two support frames 2 are fixedly connected to the two sliding seats 310 respectively. A double-acting screw 320 is rotatably connected in the installation cavity. The two sliding seats 310 are threaded to the two ends of the double-acting screw 320 with opposite rotation directions. One end of the double-acting screw 320 extends to the outside of the frame 1 and is fixedly connected to an adjustment handwheel 330. A guide rail 340 is also fixedly connected to the bottom of the installation cavity. The guide rail 340 is set along the axial direction of the double-acting screw 320. The sliding seats 310 and the guide rail 340 slide in cooperation. When the adjusting handwheel 330 is rotated, the bidirectional lead screw 320 is driven to rotate. The two sliding seats 310 move synchronously towards or away from each other along the bidirectional lead screw 320, thereby adjusting the distance between the two sets of support frames 2 to adapt to the testing requirements of mold steel samples of different specifications and sizes. This achieves synchronous adjustment of the two sets of support frames 2, ensuring that the sample is always located in the center position directly below the pressure head 2. The guide rail 340 improves the smoothness and accuracy of the sliding seat movement and avoids the occurrence of skew. Of course, in other embodiments, the adjusting handwheel 330 can be replaced by a servo motor. The servo motor is mounted on the frame 1, and the output end of the servo motor is fixedly connected to one end of the bidirectional lead screw 320. The servo motor drives the bidirectional lead screw 320 to rotate for fine adjustment of the position of the support frame 2.

[0032] In this embodiment, as Figure 8As shown, the mold steel bending strength testing device also includes a positioning mechanism 5, which includes a positioning baffle 510. The positioning baffle 510 has an L-shaped structure and is located on one side of one of the support frames 2. A longitudinal support assembly is installed between the positioning baffle 510 and the frame 1. The longitudinal support assembly is used to drive the positioning baffle 510 to move longitudinally. A linkage pressure rod 590 is provided between the longitudinal support assembly and the pressure head 4. When the linkage pressure rod 590 is not in contact with the longitudinal support assembly, the plane contact surface of the positioning baffle 510 and the support roller 210 is located on the same horizontal plane. When the linkage pressure rod 590 is in contact with the longitudinal support assembly, the positioning baffle 510 moves downward longitudinally. In the initial state where the pressure head 2 has not moved downwards and the linkage pressure rod 590 has not contacted the longitudinal support assembly, the positioning reference surface of the positioning baffle 510 and the plane contact surface of the groove 211 on the support roller 210 are at the same level. When placing the mold steel sample, the sample is pushed axially along the support roller 210 so that the end of the sample directly abuts against the vertical side wall of the L-shaped positioning baffle 510, which can quickly complete the axial centering and positioning of the sample without the need for repeated manual calibration of the sample position. When the pressure head 2 is driven to move downwards in the vertical direction and applies a bending load to the sample, the linkage pressure rod 590 fixed on the pressure head 2 moves downwards synchronously with the pressure head, so that the linkage pressure rod 590 and the longitudinal support assembly are in contact. The longitudinal support component contacts and drives the positioning baffle 510 to move downwards along the longitudinal direction in sync, so that the positioning baffle 510 is lower than the support plane of the sample. Before the sample undergoes bending deformation, the positioning baffle 510 has completely avoided the deformation space of the sample and does not contact the bending part of the sample throughout the process, thus not interfering with the bending process. The L-shaped positioning baffle 510 provides a fixed end positioning reference, and the axial alignment can be completed by one contact when the sample is placed, eliminating the need for repeated manual adjustment of the sample position, greatly shortening the sample loading time, improving the testing efficiency of batch mold steel samples, and ensuring good positioning consistency, avoiding errors in manual alignment, and ensuring that the span and stress point position of each test are consistent.

[0033] In this embodiment, as Figure 8 and Figure 9As shown, the longitudinal support assembly includes a support base 550 fixedly connected to the middle position of the frame 1. The support base 550 is fixedly connected to the frame 1 by bolts. A pair of guide rods 560 are fixedly connected to the top of the support base 550. A connecting plate 570 is slidably connected to the pair of guide rods 560. The connecting plate 570 has two guide holes for the guide rods 560 to pass through, so that the connecting plate 570 slides with the guide rods 560 through the guide holes. The top of the guide rods 560 extends above the connecting plate 570 and is threaded with a limit nut. The limit nut is used for... At the highest position of the limiting connecting plate 570, to prevent the connecting plate 570 from detaching from the guide rod 560, a second return spring 580 is sleeved between the top of the support base 550 and the bottom of the connecting plate 570 and outside the guide rod 560; a telescopic sleeve 530 is fixedly connected to one side of the connecting plate 570, and a telescopic rod 520 is slidably connected inside the telescopic sleeve 530. The telescopic rod 520 has an L-shaped structure, and the end of the telescopic rod 520 away from the telescopic sleeve 530 is fixedly connected to the positioning baffle 510. The telescopic rod 520 and the positioning baffle 510 are welded and fixed. When the linkage pressure rod 590 is not in contact with the longitudinal support assembly, the elastic force of the second return spring 580 pushes the connecting plate 570 upward, causing the connecting plate 570 to slide upward along a pair of guide rods 560 until the top surface of the connecting plate 570 abuts against the limiting nut at the top of the guide rod 560. The limiting nut limits the upper limit of the upward movement. At this time, the telescopic sleeve 530, telescopic rod 520, and positioning baffle 510, which are fixedly connected to the connecting plate 570, are simultaneously maintained in a high-positioned state. The positioning reference surface of the positioning baffle 510 is at the same level as the plane contact surface of the support roller 210, thus providing a sample end positioning function. When the pressure head 2 is loaded downward, and the linkage pressure rod 590 abuts against the top surface of the telescopic sleeve 530, the downward pressure is transmitted to the connecting plate 570 through the telescopic sleeve 530. 570 overcomes the elastic force of the second return spring 580 and slides smoothly vertically downward along the two guide rods 560. Simultaneously, the connecting plate 570 drives the telescopic rod 520 and the positioning baffle 510 to move downward longitudinally, so that the positioning baffle 510 descends as a whole below the sample support plane, completely avoiding the bending deformation space of the sample and avoiding interference with the testing process. After the bending test is completed, the pressure head 2 returns upward, and the linkage pressure rod 590 rises with the pressure head 2 and releases the pressure on the telescopic sleeve 530. The second return spring 580 releases its elastic potential energy and pushes the connecting plate 570 upward along the guide rod 560 until the connecting plate 570 abuts against the limit nut and returns to the initial high position. Simultaneously, it drives the telescopic rod 520 and the positioning baffle 510 to reset to the positioning height, automatically restoring the sample positioning function and waiting for the next sample loading.

[0034] In this embodiment, as Figure 8As shown, a sliding sleeve 541 is fixedly connected to the outer wall of the positioning baffle 510. The sliding sleeve 541 is welded and fixed to the positioning baffle 510. The axis of the sliding sleeve 541 is vertically set. A fixed slide rod 540 is slidably set inside the sliding sleeve 541. The bottom end of the fixed slide rod 540 is fixedly connected to a support frame 2 in a similar position. The fixed slide rod 540 and the support frame 2 are fixedly connected by bolts. During the longitudinal movement of the positioning baffle 510, the positioning baffle 510 slides on the fixed slide rod 540 through the sliding sleeve 541, which plays a limiting and guiding role for the positioning baffle 510, improving the support stability of the positioning baffle 510. In addition, it can also limit the positioning baffle 510 and the corresponding support frame 2 to always maintain a fixed relative position.

[0035] In a preferred embodiment of this invention, through the telescopic design of the telescopic rod 520 and the telescopic sleeve 530, when the lateral distance between the two sets of support frames 2 is adjusted by the adjustment mechanism 3, the positioning baffle 510 moves laterally synchronously with the corresponding support frame 2, causing the telescopic rod 520 to slide freely along the axial direction inside the telescopic sleeve 530. The relative sliding between the telescopic rod 520 and the telescopic sleeve 530 automatically compensates for the displacement caused by the span change, eliminating the need to disassemble and adjust the longitudinal support components. The relative positioning relationship between the positioning baffle 510 and the support frame 2 is always maintained, continuously providing a positioning reference for the mold steel sample.

[0036] In this embodiment, as Figure 10As shown, the linkage pressure rod component 590 includes a mounting sleeve 591 fixedly sleeved on the pressure head component 4. A pressure rod 592 is fixedly connected to the outer wall of the mounting sleeve 591. One end of the pressure rod 592 is welded to the mounting sleeve 591. The pressure rod 592 has a multi-segment bent structure design. Specifically, it can be a horizontal L-shaped pressure rod connected and fixed to a vertical L-shaped pressure rod. The end of the pressure rod 592 away from the mounting sleeve 591 is located directly above the telescopic sleeve 530. In the initial state, the mounting sleeve 591 is fixedly sleeved on the rod of the pressure head 4, and together with the pressure head 4, it is held in a high initial position. The end of the pressure rod 592, which is composed of a multi-segment bent structure, extends directly above the side telescopic sleeve 530, and a predetermined vertical gap is reserved between the lower end face of the pressure rod 592 and the top surface of the telescopic sleeve 530. At this time, the linkage pressure rod 590 does not apply force to the longitudinal support assembly, and the positioning baffle 510 is in a high positioning state. When the pressure head 4 is driven to move downward in the vertical direction and apply a bending load to the mold steel sample, the mounting sleeve 591 drives the pressure rod 592 to move downward vertically synchronously with the pressure head 4. The pressure head 4 moves downward to the predetermined position. After the stroke, the lower end face of the pressure rod 592 contacts the top surface of the telescopic sleeve 530. As the pressure head 4 continues to move downward, the pressure rod 592 vertically transmits the downward pressure of the pressure head to the telescopic sleeve 530, pushing the longitudinal support component to overcome the elastic force of the second return spring 580 and move downward, thereby driving the positioning baffle 510 to move downward in sync along the longitudinal direction. This completes the avoidance before the sample undergoes significant bending deformation. The positioning baffle 510 is driven to avoid and reset directly by the lifting power of the pressure head 4, without the need for additional independent drive components. The structure is simple and compact, the downward pressing action and the avoidance action are completely synchronized, and the upward action and the reset action are linked throughout the entire process without timing deviation, resulting in stronger operational stability and durability.

[0037] This embodiment also provides a testing method for a mold steel bending strength testing device, including the following steps: S1. According to the size of the mold steel sample to be tested, rotate the adjusting handwheel 330 to drive the bidirectional screw 320 to rotate, which will drive the two sliding seats 310 to move synchronously towards or away from each other along the guide rail 340, so that the two sets of support frames 2 move synchronously with the sliding seats 310, and adjust the center distance between the two support rollers 210 to the set support span. In step S1, based on the dimensions of the mold steel sample to be tested, the support span value for the three-point bending test is calculated and determined according to the corresponding test standard. The spacing between the two support rollers 210 is then adjusted. During the adjustment process, the positioning baffle 510 moves laterally synchronously with the corresponding support frame 2, and the telescopic rod 520 adaptively slides and extends within the telescopic sleeve 530, automatically compensating for the span change without the need for additional disassembly and assembly of the positioning mechanism 5. Furthermore, when the mold steel bending strength testing device is in its initial position, the first return spring 250 pushes the support roller 210 to rotate through the linkage 220, and the stop rod 260 abuts against the end of the arc-shaped limiting groove 212 to limit the movement, keeping the plane contact surface of the groove 212 on the top of the support roller 210 horizontally upward. The second return spring 580 pushes the connecting plate 570 up along the guide rod 560 to the limiting nut, causing the positioning baffle 510 to be in a high-positioned state, with the positioning reference surface of the positioning baffle 510 and the plane contact surface on the same horizontal plane.

[0038] S2. Place the mold steel sample horizontally in the placement groove 211 of the two support rollers 210, and push the sample to move axially along the support rollers 210 so that the end face of the mold steel sample abuts against the vertical side wall of the positioning baffle 510, thus completing the axial centering and positioning of the mold steel sample. At this time, the bottom surface of the mold steel sample and the plane contact surface of the placement groove 211 form a surface contact support. S3. Drive the pressure head 4 to descend at a constant speed in the vertical direction. When the pressure head 4 is close to the mold steel sample but has not yet contacted the mold steel sample, the linkage pressure rod 590 contacts the longitudinal support assembly, causing the positioning baffle 510 to move down synchronously away from the mold steel sample. In step S3, the pressure head 4 continues to be loaded downwards, and the linkage pressure rod 590 fixed on the pressure head 4 moves downwards accordingly. The lower end face of the pressure rod 592 contacts the top surface of the telescopic sleeve 530 and applies downward pressure. The pressure is transmitted to the connecting plate 570 through the telescopic sleeve 530, overcoming the elastic force of the second return spring 580, and driving the connecting plate 580 to slide vertically down along the two guide rods 560. At the same time, the positioning baffle 510 moves downwards longitudinally through the telescopic rod 520. Meanwhile, the sliding sleeve 541 on the side of the positioning baffle 510 slides down synchronously along the fixed slide rod 540, providing lateral guidance and ensuring smooth lifting. Before the mold steel sample bends and deforms, the positioning baffle 510 descends as a whole below the support plane of the mold steel sample, completely avoiding the bending deformation area of ​​the mold steel sample and not interfering with the bending process by additional constraint force.

[0039] S4. The pressure head 4 continues to move downward and contacts the mid-span position of the mold steel sample, applying a bending load to the mold steel sample. The mold steel sample gradually bends and deforms, and the mold steel sample drives the support roller 210 to rotate adaptively around its own axis. The planar contact surface of the groove 211 always maintains a surface contact state with the bottom surface of the mold steel sample, effectively dispersing the contact stress at the support point. In step S4, during the bending process of the mold steel sample, the support roller 210 maintains surface contact as it rotates, and the linkage 220 at the end of the support roller 210 swings synchronously with the support roller 210. The swing rod 222 of the linkage 220 can swing along the arc rod 230 and compress the first return spring 250.

[0040] S5. After the test is completed, the driving pressure head 4 returns to the vertical direction, the linkage pressure rod 590 rises synchronously with the pressure head 4, the longitudinal support component drives the positioning baffle 510 to move upward and reset to the initial positioning height, and the reset component drives the support roller 210 to rotate and reset to the initial position. In step S5, the linkage pressure rod 590 returns upward with the pressure head 4, the second reset spring 580 releases its elastic potential energy, pushes the connecting plate 570 to rise along the guide rod 560, and drives the positioning baffle 510 to rise and reset synchronously until the connecting plate abuts the limit nut and returns to the initial positioning height. At the same time, the first reset spring 250 releases its elastic force, drives the linkage 220 to rotate in the opposite direction, and makes the support roller 210 automatically reset to the initial position.

[0041] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the following preferred embodiments; however, those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0042] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A device for testing the bending strength of mold steel, used to test the bending strength of a mold steel sample (6), characterized in that, Including rack (1); A pressure head (4) is disposed on the upper part of the frame (1) and moves in the vertical direction; The support frame (2) is located on the frame (1) and has two sets of support frames (2) symmetrically distributed on the left and right sides of the pressure head (4). The top of the support frame (2) is rotatably connected to a support roller (210). The top of the support roller (210) is provided with a placement groove (211) along the axial direction. The bottom end of the placement groove (211) is a planar contact surface. Both ends of the support roller (210) extend to the outside of the support frame (2) and are installed with a reset component between them and the support frame (2). In the initial state, the reset component does not operate, and the mold steel sample (6) is placed in the placement groove (211) of the two support rollers (210), and the plane contact surface with the placement groove (211) is in surface contact. The positioning mechanism (5) includes a positioning baffle (510), which is an L-shaped structure and is located on one side of one of the support frames (2). A longitudinal support assembly is installed between the positioning baffle (510) and the frame (1). The longitudinal support assembly is used to drive the positioning baffle (510) to move longitudinally. A linkage pressure rod (590) is provided between the longitudinal support assembly and the pressure head (4). When the linkage pressure bar (590) is not in contact with the longitudinal support assembly, the planar contact surfaces of the positioning baffle (510) and the support roller (210) are located on the same horizontal plane; When the linkage pressure rod (590) comes into contact with the longitudinal support assembly, the positioning baffle (510) moves downward in the longitudinal direction.

2. The die steel bending strength testing device according to claim 1, characterized in that, The reset assembly includes a linkage (220) installed at the end of the support roller (210). The reset assembly also includes an arc-shaped rod (230) disposed on the outside of the support frame (2). Both ends of the arc-shaped rod (230) are fixedly connected to the support frame (2). A first reset spring (250) is sleeved on the outside of the arc-shaped rod (230). One end of the linkage (220) is sleeved on the arc-shaped rod (230).

3. The die steel bending strength testing device according to claim 2, characterized in that, The linkage (220) includes an embedded block (221) and a swing rod (222) fixedly connected to the outer wall of the embedded block (221). The swing rod (222) has a through hole (223) at one end away from the embedded block (221). The swing rod (222) is sleeved on the arc rod (230) through the through hole (223). One end of the first reset spring (250) presses against the outer wall of the swing rod (222). The end of the support roller (210) has an embedded groove. The embedded block (221) is inserted into the embedded groove and fixedly connected to the support roller (210) by bolts.

4. The die steel bending strength testing device according to claim 1, characterized in that, The lower circumference of the support roller (210) is provided with an arc-shaped limiting groove (212) along the axial direction, and the support frame (2) is fixedly connected with a stop bar (260) inside the arc-shaped limiting groove (212).

5. The die steel bending strength testing device according to claim 1, characterized in that, The mold steel bending strength testing device also includes an adjustment mechanism (3), which is used to adjust the distance between the two sets of support frames (2).

6. The die steel bending strength testing device according to claim 5, characterized in that, The frame (1) has an internal mounting cavity. The adjustment mechanism (3) includes two sliding seats (310) located in the mounting cavity. The two support frames (2) are fixedly connected to the two sliding seats (310) respectively. A bidirectional lead screw (320) is rotatably connected in the mounting cavity. The two sliding seats (310) are threaded to the two ends of the bidirectional lead screw (320) with opposite rotation directions. One end of the bidirectional lead screw (320) extends to the outside of the frame (1) and is fixedly connected to an adjustment handwheel (330). A guide rail (340) is also fixedly connected to the bottom of the mounting cavity. The guide rail (340) is axially arranged along the bidirectional lead screw (320). The sliding seats (310) and the guide rail (340) slide in cooperation.

7. The die steel bending strength testing device according to claim 1, characterized in that, The longitudinal support assembly includes a support base (550) fixedly connected to the middle position of the frame (1). A pair of guide rods (560) are fixedly connected to the top of the support base (550). A connecting plate (570) is slidably connected to the pair of guide rods (560). The top of the guide rods (560) extends above the connecting plate (570) and is threaded with a limit nut. A second return spring (580) is sleeved between the top of the support base (550) and the bottom of the connecting plate (570) and outside the guide rods (560). A telescopic sleeve (530) is fixedly connected to one side of the connecting plate (570). A telescopic rod (520) is slidably connected inside the telescopic sleeve (530). The telescopic rod (520) has an L-shaped structure. The end of the telescopic rod (520) away from the telescopic sleeve (530) is fixedly connected to the positioning baffle (510).

8. The die steel bending strength testing device according to claim 7, characterized in that, A sliding sleeve (541) is fixedly connected to the outer wall of the positioning baffle (510). The axis of the sliding sleeve (541) is vertically set. A fixed slide rod (540) is slidably set inside the sliding sleeve (541). The bottom end of the fixed slide rod (540) is fixedly connected to the support frame (2) in a similar position.

9. A device for testing the bending strength of mold steel according to claim 7, characterized in that, The linkage pressure rod (590) includes a mounting sleeve (591) fixedly sleeved on the pressure head (4). A pressure rod (592) is fixedly connected to the outer wall of the mounting sleeve (591). The pressure rod (592) has a multi-segment bending structure design. The end of the pressure rod (592) away from the mounting sleeve (591) is located directly above the telescopic sleeve (530).

10. The testing method of the mold steel bending strength testing device according to any one of claims 1-9, characterized in that, Includes the following steps: S1. According to the size of the mold steel sample to be tested, turn the adjusting handwheel (330) to drive the bidirectional screw (320) to rotate, which will drive the two sliding seats (310) to move synchronously towards or away from each other along the guide rail (340), so that the two sets of support frames (2) move synchronously with the sliding seats (310), and adjust the center distance between the two support rollers (210) to the set support span. S2. Place the mold steel sample horizontally in the placement groove (211) of the two support rollers (210), push the sample to move axially along the support rollers (210), so that the end face of the mold steel sample abuts against the vertical side wall of the positioning baffle (510), and complete the axial centering and positioning of the mold steel sample. At this time, the bottom surface of the mold steel sample and the plane contact surface of the placement groove (211) form a surface contact support. S3. Drive the pressure head (4) to descend at a constant speed in the vertical direction. When the pressure head (4) is close to the mold steel sample but does not contact the mold steel sample, the linkage pressure rod (590) contacts the longitudinal support assembly, causing the positioning baffle (510) to move down synchronously away from the mold steel sample. S4. The pressure head (4) continues to descend and contacts the mid-span position of the mold steel sample, applying a bending load to the mold steel sample. The mold steel sample gradually undergoes bending deformation, and the mold steel sample drives the support roller (210) to rotate adaptively around its own axis. The planar contact surface of the placement groove (211) always maintains a surface contact state with the bottom surface of the mold steel sample, effectively dispersing the contact stress at the support point. S5. After the test is completed, the driving pressure head (4) returns upward in the vertical direction, and the linkage pressure rod (590) rises synchronously with the pressure head (4). The longitudinal support component drives the positioning baffle (510) to move upward and reset back to the initial positioning height. The reset component drives the support roller (210) to rotate and reset back to the initial position.

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