Local heating detection equipment for high-temperature-resistant heat-resisting sheet for power battery

Abstract

The invention is suitable for the field of detection equipment, and provides a power battery high temperature resistant heat insulation sheet local heating detection equipment, which comprises a base table plate, the left and right sides of the base table plate are respectively provided with a group of support frames, the middle parts of the left and right groups of support frames are respectively provided with a positioning frame, and the front and rear ends of the positioning frame are respectively provided with a detachable auxiliary frame. The positioning frame and the auxiliary frame are rotationally arranged in the middle of the supporting frame; a straight rod is arranged in the middle of the top of the base table plate, and the two ends of the straight rod are fixedly connected with the top face of the base table plate through shaft seats. When the device is used, a battery heat insulation sheet to be treated is put in from the position of the assembly groove, and the irradiation table irradiates and heats the battery heat insulation sheet, so that the battery heat insulation sheet has double conditions of bending and heating, and the battery heat insulation sheet can be bent and heated when coming out and being cooled. A worker can observe the rebound resilience of the battery heat insulation sheet under the dual conditions of bending and heating.

Description

Technical Field

[0001] The present invention belongs to the field of detection equipment, and particularly relates to a local heating detection device for a high-temperature resistant heat insulation sheet for a power battery. Background Art

[0002] With the development of industrial technology, modern detection equipment technology has become more and more perfect. The battery heat insulation pad is centered on pre-oxidized fiber or other types of aerogel composite materials and is formed by hot pressing or coating and compounding of polymer materials. It has excellent heat insulation and buffering functions and is mainly used for thermal protection between power lithium battery cells to prevent thermal runaway of the cells.

[0003] A detection device and method for a high-temperature resistant heat insulation sheet for a power battery disclosed in Patent CN118189501A belong to the technical field of battery heat insulation sheet detection, including a main body module and an automatic blanking and cooling module. The main body module includes a mounting frame, and a double-sided high-temperature test component is arranged on the top of the mounting frame. Two heating plates are arranged on the double-sided high-temperature test component. The automatic blanking and cooling module includes a steering column rotatably connected between the inner walls on both sides of the steering column. Four first U-shaped plates are fixedly connected to the outer surface of the steering column at equal intervals in a ring shape. First U-shaped limiting grooves are formed inside the four first U-shaped plates. Through the settings of the steering column, the automatic clamping component, the annular plate, the annular track groove, the driving component, the automatic cooling component, and the separation and arrangement component, the device can automatically blank and cool the heat insulation sheet after the heating test is completed, without manual blanking, preventing the problem of scalding.

[0004] However, this device still has defects when in use. First, the heating method of the battery heat insulation sheet by this device is relatively fixed. The battery heat insulation sheet is prone to bending when being impacted, and during the operation of the locomotive, the temperature on the surface of the battery is relatively high. Therefore, the battery heat insulation sheet is also in a high-temperature environment when being impacted. It is necessary to detect whether the battery heat insulation sheet can rebound to its original flat state under the dual conditions of being impacted and in a high-temperature environment. Second, the battery heat insulation sheet will bend when locally heated, and this bending will press the adjacent battery, which will cause physical extrusion damage to the battery. Summary of the Invention

[0005] The purpose of the present invention is to provide a local heating detection device for high-temperature resistant heat insulation sheets for power batteries in view of the deficiencies of the prior art. When this device is in use, the battery heat insulation sheet to be processed is placed in from the position of the assembly groove. The stepping motor drives two conveying wheels to rotate through the horizontal axis. During the operation of the conveyor belt on the outside of the conveying wheels, the push rods on the outer side wall of the conveyor belt will push the battery heat insulation sheet forward. When the battery heat insulation sheet contacts the bottom arc surface of the arc-shaped frame, the edge of the battery heat insulation sheet will be pressed by the bottom arc surface of the arc-shaped frame and become bent. At the same time, the irradiation table irradiates and heats the battery heat insulation sheet. Thus, the battery heat insulation sheet has the dual conditions of bending and heating. When the battery heat insulation sheet comes out and cools, the staff can observe the resilience properties of the battery heat insulation sheet under the dual conditions of bending and heating, so as to solve the problems mentioned in the background art.

[0006] To solve the above problems, the present invention provides the following technical solutions: A local heating detection device for high-temperature resistant heat insulation sheets for power batteries, including a base plate. A set of support frames are arranged on both the left and right sides of the base plate. A positioning frame is arranged in the middle of the left and right support frames. Removable accessory frames are arranged at both the front and rear ends of the positioning frame. The positioning frame and the accessory frame are rotatably arranged in the middle of the support frames; A straight rod is arranged in the middle of the top of the base plate. Both ends of the straight rod are fixedly connected to the top surface of the base plate through shaft seats; Both the bottom of the positioning frame and the accessory frame are provided with, and forms an inward 15-degree angle with the vertical plane. An arc-shaped frame is detachably installed on the side wall of. A number of steering steel balls are locally annularly arrayed on the bottom arc surface of the arc-shaped frame. Lubricating steel balls are linearly arrayed on the inner side wall of the bottom of the accessory frame. The height of the lowest part of the arc surface of the arc-shaped frame is lower than the axis height of the straight rod; Battery heat insulation sheet pushing components are also arranged on both sides of the straight rod. A light heating adjustment mechanism is arranged above the base plate.

[0007] During use, the battery heat insulation sheet to be processed is placed in from the position of the assembly groove. The battery heat insulation sheet pushing component pushes the workpiece forward. When the battery heat insulation sheet contacts the bottom arc surface of the arc-shaped frame, the edge of the battery heat insulation sheet will be pressed by the bottom arc surface of the arc-shaped frame and become bent. At the same time, the irradiation table irradiates and heats the battery heat insulation sheet. Thus, the battery heat insulation sheet has the dual conditions of bending and heating. When the battery heat insulation sheet comes out and cools, the staff can observe the resilience properties of the battery heat insulation sheet under the dual conditions of bending and heating.

[0008] Further, the battery heat insulation sheet pushing component includes two conveying shaft seats arranged on the front and rear side walls of the base plate. A horizontal axis is rotatably arranged on one side of the conveying shaft seat. The front horizontal axis is connected to the output shaft of the stepping motor. Two conveying wheels are fixedly installed on the horizontal axis. Two conveyor belts are wound and connected between the front and rear conveying wheels. Two push rods are arranged on the side wall of the conveyor belt.

[0009] During use, the stepping motor drives two conveying wheels to rotate through the horizontal axis. During the operation of the conveyor belt on the outer side of the conveying wheels, the pushing rods on the outer side wall of the conveyor belt will push the battery heat insulation sheet forward.

[0010] Furthermore, two fixed bolt heads are provided on the side wall of the conveyor belt, and a threaded port is provided at the bottom of the pushing rod. The threaded port at the bottom of the pushing rod is connected to the threaded head.

[0011] During use, when the pushing rod needs to be replaced with a different length or is damaged and needs to be repaired, the pushing rod is rotated and unscrewed, and then a new pushing rod can be replaced.

[0012] Furthermore, a square hole is provided at the end of the support frame, and a square pin rod is movably inserted inside the square hole. A short tube is provided on the side wall of the accessory frame facing away from the positioning frame, and a docking square hole is provided inside the short tube. The square hole on the side wall of the support frame and the docking square hole inside the short tube are inserted through the square pin rod. Through holes are provided at the tops of the positioning frame and the accessory frame.

[0013] During use, after pulling out the square pin rod, the positioning frame and the accessory frame can be rotated 90 degrees and laid flat. At this time, after the through holes are laid flat, the straight rod is removed, and the staff can put the battery heat insulation sheet into the through hole. The battery heat insulation sheet under the light can be heated, and the staff can observe the bending situation of different parts of the battery after heating.

[0014] Furthermore, a linear array of steel balls is rotatably provided on both inner side walls of the through hole, and the gap between the steel balls is greater than the thickness of the battery heat insulation sheet to be detected.

[0015] During use, the steel balls on both inner side walls of the through hole reduce the frictional force of the battery heat insulation sheet during pushing.

[0016] Furthermore, the light heating adjustment mechanism includes an irradiation table fixedly provided above the base plate. A heating lamp device is provided inside the irradiation table. Beam frames are provided on both the left and right sides of the base plate. A positioning motor is fixedly installed at the top of the beam frame. Three fork frames with a deviation of 120 degrees from each other are provided at the end of the rotating shaft of the positioning motor. A light shielding plate is provided at the end of the fork frame. The heights of the fork frames and the light shielding plates on the left and right sides are inconsistent. The height of the left fork frame and the light shielding plate is greater than the height of the right fork frame and the light shielding plate.

[0017] During use, when the two positioning motors drive the fork frames and the light shielding plates to rotate, the light shielding plates can take turns to reach below the irradiation table. The light shielding plates can block light individually, and the two light shielding plates can also overlap to block light, which can create a situation of partial light transmission. The battery heat insulation sheet under the light can be locally heated.

[0018] Furthermore, three kinds of light-transmitting holes are arranged at the center of the light-shielding plate, and the shapes of the three kinds of light-transmitting holes are circular, rectangular, and triangular respectively.

[0019] During use, the three kinds of light-transmitting holes in the left and right groups can overlap with each other, which allows light to pass through light controls of different shapes, and then different-shaped heating areas can be simulated, and the staff can observe the bending conditions of different local heating.

[0020] Compared with the prior art, the embodiments of the present application mainly have the following beneficial effects:

[0021] First, when the device is in use, the battery heat insulation sheet to be processed is placed into the assembly groove. The stepping motor drives the two conveying wheels to rotate through the horizontal shaft. During the operation of the conveyor belt on the outer side of the conveying wheel, the push rod on the outer side wall of the conveyor belt will push the battery heat insulation sheet forward. When the battery heat insulation sheet touches the bottom arc surface of the arc-shaped frame, the edge of the battery heat insulation sheet will be pressed by the bottom arc surface of the arc-shaped frame and become bent. At the same time, the irradiation table irradiates and heats the battery heat insulation sheet. Thus, the battery heat insulation sheet has both bending and heating conditions. When the battery heat insulation sheet comes out and cools down, the staff can observe the resilience properties of the battery heat insulation sheet under the dual conditions of bending and heating.

[0022] Second, after pulling out the square pin rod, the positioning frame and the accessory frame can be rotated 90 degrees and laid flat. At this time, after the through slot is laid flat, the straight rod is removed, and the staff can place the battery heat insulation sheet into the through slot. At the same time, during the rotation of the two positioning motors driving the bifurcated frame and the light-shielding plate, the light-shielding plate can reach below the irradiation table in turn. The light-shielding plate can block light alone, and the two light-shielding plates can also overlap to block light, which can create a situation of partial light transmission. The battery heat insulation sheet under the light can be locally heated, and the staff can observe the bending conditions of different parts of the battery heat insulation sheet after heating. Description of the Drawings

[0023] Figure 1 It is a front view schematic diagram of the present invention.

[0024] Figure 2 It is a schematic diagram of the positioning frame of the present invention.

[0025] Figure 3 It is a schematic diagram of the second form of the positioning frame of the present invention.

[0026] Figure 4 It is of the present invention Figure 2 Partial enlarged view of A.

[0027] Figure 5 It is of the present invention Figure 3Partial enlarged view of part B.

[0028] Figure 6 Schematic diagram of the arc-shaped frame of the present invention.

[0029] Figure 7 Schematic diagram of the through slot of the present invention.

[0030] Figure 8 Schematic diagram of the irradiation table of the present invention.

[0031] Explanation of reference numerals in the drawings:

[0032] Base plate 1, support frame 101, square pin rod 102, straight rod 103, irradiation table 2, cantilever frame 201, positioning motor 202, bifurcated frame 203, light shielding plate 204, positioning frame 3, accessory frame 301, short tube 302, lubricating steel ball 303, arc-shaped frame 4, steering steel ball 401, assembly groove 402, stepper motor 5, horizontal shaft 501, conveying wheel 502, conveyor belt 503, push rod 504, through slot 6. Detailed implementation manners

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of this application or the above drawings are used to distinguish different objects and not to describe a specific order.

[0034] Referring to "embodiment" herein means that a specific feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0035] The present invention provides a local heating detection device for high-temperature heat-insulating sheets used in power batteries, as Figure 1-8As shown, it includes a base plate 1. A set of support frames 101 are arranged on both the left and right sides of the base plate 1. A positioning frame 3 is arranged in the middle of the left and right support frames 101. Removable accessory frames 301 are arranged at both the front and rear ends of the positioning frame 3. The positioning frame 3 and the accessory frame 301 are rotatably arranged in the middle of the support frame 101; A straight rod 103 is arranged at the middle position of the top of the base plate 1. Both ends of the straight rod 103 are fixedly connected to the top surface of the base plate 1 through shaft seats; Assembly grooves 402 are arranged at the bottoms of both the positioning frame 3 and the accessory frame 301. The assembly grooves 402 form an inward 15-degree angle with the vertical plane. An arc-shaped frame 4 is detachably installed on the side wall of the assembly groove 402. A number of steering steel balls 401 are locally annularly arrayed on the arc surface at the bottom of the arc-shaped frame 4. Lubricating steel balls 303 in a linear array are arranged on the inner side wall of the assembly groove 402 at the bottom of the accessory frame 301. The height of the lowest part of the arc surface of the arc-shaped frame 4 is lower than the axis height of the straight rod 103; Battery heat insulation sheet propulsion components are also arranged on both sides of the straight rod 103. A light heating adjustment mechanism is arranged above the base plate 1.

[0036] In this embodiment, the battery heat insulation sheet to be processed is placed from the position of the assembly groove 402. The battery heat insulation sheet propulsion component pushes the workpiece forward. When the battery heat insulation sheet contacts the arc surface at the bottom of the arc-shaped frame 4, the edge of the battery heat insulation sheet will be pressed by the arc surface at the bottom of the arc-shaped frame 4 and become bent. At the same time, the irradiation table 2 irradiates and heats the battery heat insulation sheet. Then the battery heat insulation sheet has both the conditions of bending and heating. When the battery heat insulation sheet comes out and cools, the staff can observe the resilience properties of the battery heat insulation sheet under the dual conditions of bending and heating.

[0037] In a further embodiment of the present invention, as Figure 1-5 shown, the battery heat insulation sheet propulsion component includes two conveying shaft seats arranged on the front and rear side walls of the base plate 1. A horizontal shaft 501 is rotatably arranged on one side of the conveying shaft seat. The front horizontal shaft 501 is connected to the output shaft of the stepping motor 5. Two conveying wheels 502 are fixedly installed on the horizontal shaft 501. Two conveyor belts 503 are wound and connected between the front and rear conveying wheels 502. Two propulsion rods 504 are arranged on the side wall of the conveyor belt 503.

[0038] In this embodiment, the stepping motor 5 drives the two conveying wheels 502 to rotate through the horizontal shaft 501. During the operation of the conveyor belt 503 outside the conveying wheel 02, the propulsion rod 504 on the outer side wall of the conveyor belt 503 will push the battery heat insulation sheet forward.

[0039] In a further embodiment of the present invention, as Figure 1-5As shown, two fixed bolt heads are provided on the side wall of the conveyor belt 503, and a threaded port is provided at the bottom of the push rod 504. The threaded port at the bottom of the push rod 504 is connected to the threaded head.

[0040] In this embodiment, when the push rod 504 needs to be replaced with a different length or is damaged and needs to be repaired, the push rod 504 is rotated and unscrewed, and then a new push rod 504 can be replaced.

[0041] In a further embodiment of the present invention, as Figure 1-7 shown, a square hole is provided at the end of the support frame 101, and a square pin rod 102 is movably inserted into the square hole. A short tube 302 is provided on the side wall of the accessory frame 301 facing away from the positioning frame 3, and a docking square hole is provided inside the short tube 302. The square hole on the side wall of the support frame 101 and the docking square hole inside the short tube 302 are inserted through the square pin rod 102. Through slots 6 are provided at the tops of both the positioning frame 3 and the accessory frame 301.

[0042] In this embodiment, after pulling out the square pin rod 102, the positioning frame 3 and the accessory frame 301 can be twisted by ninety degrees and laid flat. At this time, after the through slots 6 are laid flat, the straight rod 103 is removed, and the staff can put the battery heat insulation sheet into the through slots 6. The battery heat insulation sheet under the light can be heated, and the staff can observe the bending situation of the battery heat insulation sheet after heating.

[0043] In a further embodiment of the present invention, as Figure 6-7 shown, linear arrays of steel balls are rotatably provided on both inner side walls of the through slot 6, and the gap between the steel balls is greater than the thickness of the battery heat insulation sheet to be detected.

[0044] In this embodiment, the steel balls on both inner side walls of the through slot 6 reduce the frictional force of the battery heat insulation sheet being pushed.

[0045] In a further embodiment of the present invention, as Figure 1 、 8 shown, the light heating adjustment mechanism includes an irradiation table 2 fixedly provided above the base plate 1. A heating lamp device is provided inside the irradiation table 2. Cantilever frames 201 are provided on both the left and right sides of the base plate 1. A positioning motor 202 is fixedly installed at the top of the cantilever frame 201. Three fork frames 203 that deviate from each other by one hundred and twenty degrees are provided at the end of the rotating shaft of the positioning motor 202. A light shielding plate 204 is provided at the end of the fork frame 203. The fork frames 203 and the light shielding plates 204 on the left and right sides have different heights. The height of the left fork frame 203 and the light shielding plate 204 is greater than the height of the right fork frame 203 and the light shielding plate 204.

[0046] In this embodiment, during the rotation of the forked frame 203 and the light-shielding plate 204 driven by the two positioning motors 202, the light-shielding plate 204 can alternately reach below the irradiation table. The light-shielding plate 204 can block light individually, and the two light-shielding plates 204 can also overlap to block light, which can create a situation of partial light transmission. The battery heat insulation sheet under the light can be locally heated.

[0047] In a further embodiment of the present invention, as Figure 1 , 8 shown, three kinds of light-transmitting holes are provided at the center of the light-shielding plate 204, and the shapes of the three kinds of light-transmitting holes are circular, rectangular, and triangular respectively.

[0048] In this embodiment, the three kinds of light-transmitting holes in the left and right groups can overlap each other, which can allow light to pass through different-shaped light controls, and then different-shaped heating areas can be simulated. The staff can observe the bending conditions of different local heating.

[0049] It should be noted that for the foregoing embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps may be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0050] In several embodiments provided by the present application, it should be understood that the disclosed device can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the above-mentioned unit division can have other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point, the displayed or discussed coupling or communication connection between each other can be through some interfaces. The indirect coupling or communication connection between devices or units can be in the form of telecommunications or other forms.

[0051] The units described above as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place, or they can be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0052] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on these embodiments, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still, without conflict and without creative efforts, combine, add or delete the features in the embodiments of the present invention according to the circumstances or make other adjustments, so as to obtain different technical solutions that essentially do not deviate from the concept of the present invention, and these technical solutions also fall within the scope of protection of the present invention.

Claims

1. A local heating detection device for a high-temperature resistant heat insulation sheet used in a power battery, characterized in that: It includes a base plate (1), a set of support frames (101) are arranged on both the left and right sides of the base plate (1), a positioning frame (3) is arranged in the middle of the left and right support frames (101), detachable auxiliary frames (301) are arranged at both the front and rear ends of the positioning frame (3), and the positioning frame (3) and the auxiliary frame (301) are rotatably arranged in the middle of the support frame (101); A straight rod (103) is arranged at the middle position of the top of the base plate (1), and both ends of the straight rod (103) are fixedly connected to the top surface of the base plate (1) through shaft seats; Assembly grooves (402) are arranged at the bottoms of both the positioning frame (3) and the auxiliary frame (301), the assembly grooves (402) form an inward angle of fifteen degrees with the vertical plane, an arc-shaped frame (4) is detachably installed on the side wall of the assembly groove (402), a number of steering steel balls (401) are locally annularly arrayed on the arc surface at the bottom of the arc-shaped frame (4), and lubricating steel balls (303) in a linear array are arranged on the inner side wall of the assembly groove (402) at the bottom of the auxiliary frame (301), and the height of the lowest part of the arc surface of the arc-shaped frame (4) is lower than the axis height of the straight rod (103); Battery heat insulation sheet propulsion components are also arranged on both sides of the straight rod (103), and a light heating adjustment mechanism is arranged above the base plate (1).

2. The local heating detection device for a high-temperature resistant heat insulation sheet for a power battery according to claim 1, characterized in that: The battery heat insulation sheet propulsion components include two conveying shaft seats arranged on the front and rear side walls of the base plate (1), a horizontal shaft (501) is rotatably arranged on one side of the conveying shaft seat, the front horizontal shaft (501) is connected to the output shaft of a stepping motor (5), two conveying wheels (502) are fixedly installed on the horizontal shaft (501), and two conveyor belts (503) are wound and connected between the front and rear conveying wheels (502), and two propulsion rods (504) are arranged on the side wall of the conveyor belt (503).

3. The local heating detection device for a high-temperature resistant heat insulation sheet used in a power battery according to claim 2, characterized in that: Two fixed bolt heads are arranged on the side wall of the conveyor belt (503), a threaded port is arranged at the bottom of the propulsion rod (504), and the threaded port at the bottom of the propulsion rod (504) is connected to the threaded head.

4. A local heating detection device for a high-temperature resistant heat insulation sheet for a power battery according to claim 1, characterized in that: A square hole is arranged at the end of the support frame (101), a square pin rod (102) is movably inserted into the square hole, a short tube (302) is arranged on the side wall of the auxiliary frame (301) facing away from the positioning frame (3), a docking square hole is arranged inside the short tube (302), and the square hole on the side wall of the support frame (101) and the docking square hole inside the short tube (302) are plugged through the square pin rod (102), and through slots (6) are arranged at the tops of both the positioning frame (3) and the auxiliary frame (301).

5. The local heating detection device for a high-temperature resistant heat insulation sheet for a power battery according to claim 4, characterized in that: Linear arrays of steel balls are rotatably arranged on both inner side walls of the through slot (6), and the gap between the steel balls is greater than the thickness of the battery heat insulation sheet to be detected.

6. The local heating detection device for a high-temperature resistant heat insulation sheet for a power battery according to claim 1, wherein: The light heating adjustment mechanism includes an irradiation table (2) fixedly arranged above a base plate (1). A heating lamp device is arranged inside the irradiation table (2). Cantilever frames (201) are arranged on both the left and right sides of the base plate (1). A positioning motor (202) is fixedly installed at the top of the cantilever frame (201). Three fork-shaped frames (203) that deviate from each other by 120 degrees are arranged at the end of the rotating shaft of the positioning motor (202). A light shielding plate (204) is arranged at the end of the fork-shaped frame (203). The fork-shaped frames (203) and the light shielding plates (204) on the left and right sides have different heights. The height of the left fork-shaped frame (203) and the light shielding plate (204) is greater than the height of the right fork-shaped frame (203) and the light shielding plate (204).

7. An apparatus for locally heating and detecting a high-temperature heat-insulating sheet for a power battery according to claim 6, characterized in that: Three kinds of light-transmitting holes are arranged at the center of the light shielding plate (204). The shapes of the three kinds of light-transmitting holes are circular, rectangular, and triangular respectively.

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