JP7360038B2 - Rubber mold release evaluation method and device - Google Patents

Description

The present invention relates to a method and apparatus for evaluating the releasability of rubber, and more specifically, to a method and apparatus for evaluating the releasability of rubber, and more particularly, to a method and apparatus for evaluating the releasability of rubber, and more particularly, to a method and apparatus for evaluating the releasability of rubber, and more particularly, to a method and apparatus for evaluating the releasability of rubber, and more particularly, to a method and apparatus for evaluating the releasability of rubber, and more particularly, to a method and apparatus for evaluating the releasability of rubber. The present invention relates to a mold releasability evaluation method and device.

Rubber products such as pneumatic tires are manufactured by vulcanizing unvulcanized rubber in a vulcanization mold. When the rubber product manufactured after vulcanization is removed from the vulcanization mold, if the rubber product (vulcanized rubber) is difficult to release from the vulcanization mold, problems such as rubber chipping occur. Such defects lead to poor appearance of the rubber product. Alternatively, if the rubber is chipped and becomes clogged in the vent hole of the vulcanization mold, work to clear the blockage is required, leading to a decrease in productivity.

When a vulcanizing mold is used repeatedly, dirt accumulates on the molding surface, and the mold releasability changes accordingly. Since vulcanization on a dirty molding surface will affect the quality of the rubber product, the molding surface is cleaned after a predetermined period or a predetermined number of vulcanizations. Therefore, understanding the change in mold releasability over time is useful for ensuring the quality of rubber products and determining appropriate cleaning timing for vulcanization molds. Furthermore, it is also useful to understand changes over time in the releasability (releasability) of vulcanized rubber not only from a vulcanizing mold but also from, for example, a vulcanizing bladder.

Although it is not a technology for evaluating the mold releasability of vulcanized rubber, for example, an evaluation method has been proposed for selecting vulcanized adhesives with low mold contamination that are suitable for manufacturing rubber-metal composites (patented). (See Reference 1). In this evaluation method, unvulcanized rubber is vulcanized and bonded to the surface of a metal substrate that has undergone a predetermined adhesive treatment, and then the vulcanized rubber is peeled at a 90° angle to the surface of the metal substrate to determine the peel strength. Measure. In other words, this evaluation method evaluates the adhesion between vulcanized rubber and metal, and is not a method for evaluating the releasability of rubber and metal that are in close contact with each other without adhesion. Nor is it a method for evaluating changes over time. To evaluate the adhesion of vulcanized rubber, the peel strength is often measured when the vulcanized rubber is peeled from a metal surface at an angle of 90°.

It takes a great deal of time and cost to repeatedly test a vulcanized rubber vulcanized in an actual vulcanization mold to release it from the vulcanization mold to understand changes in releasability. Therefore, there is room for improvement in understanding changes over time in mold release properties (peelability) when releasing rubber that is in close contact without adhering to a vulcanization mold or the like.

Japanese Patent Application Publication No. 2002-243629

An object of the present invention is to provide a rubber mold release property evaluation method and device that can easily and efficiently grasp changes in mold release property over time when rubber is repeatedly released from a vulcanization mold or the like. .

In order to achieve the above object, the method for evaluating the mold releasability of rubber of the present invention involves heating unvulcanized rubber while pressing it onto a predetermined area of a flat target surface of a base, so that it does not adhere to the target surface. After forming a test specimen of a small piece of vulcanized or semi-vulcanized rubber that is in close contact with A tensile process is performed in which a vertical tensile force is applied to the entire contact surface with the target surface at once to peel the test specimen from the predetermined area, and the process from the formation of the test specimen to the completion of the tensile process is carried out. A series of steps are repeated in the same area without changing the position of the predetermined area to form a large number of test specimens, and the surface state of the predetermined area after the tensile process for each test specimen is evaluated. Characterized by grasping.

The rubber mold releasability evaluation device of the present invention includes a base having a flat target surface, and an unvulcanized rubber pressed against a predetermined area of the target surface and heated to adhere to the target surface without adhesion. a heating mechanism for forming a test piece of a small piece of vulcanized or semi-vulcanized rubber; and after forming the test piece, moving at least one of the test piece and the base in a direction away from each other; a tensile mechanism that performs a tensile step of peeling the test specimen from the predetermined area by applying a vertical tensile force to the entire contact surface of the test specimen with the target surface at once; surface grasping means for grasping the surface condition of the unvulcanized rubber; and a transport mechanism for relatively moving the unvulcanized rubber from a predetermined preparation position to the predetermined area, and relatively moving the test specimen from the predetermined area to a predetermined storage position. In preparation, the series of processes from the formation of the test specimen to the completion of the tension process is set to be repeated in the same area without changing the position of the predetermined area, and for each of the numerous test specimens formed. The present invention is characterized in that the surface condition of the predetermined area after the tensioning step is grasped by the surface grasping means.

According to the present invention, by performing a tensile process in which a tensile force is applied in a vertical direction to the entire contact surface of the test specimen with the target surface at once to peel the test specimen from the predetermined area, it is possible to actually The conditions approximate the conditions under which rubber is most difficult to release from a vulcanization mold in the manufacturing process of rubber products. A series of processes from forming the test specimen to completing the tensioning process are repeated by setting the predetermined area in the same area without changing the position, thereby forming a large number of test specimens, thereby making it possible to repeat the rubber. The actual manufacturing process of releasing from a vulcanization mold can be easily reproduced. By checking the surface condition of the predetermined area after each of the tensile processes for a large number of test specimens, it is possible to efficiently check changes over time in the releasability of the rubber.

FIG. 2 is an explanatory diagram illustrating an embodiment of a rubber releasability evaluation device in a front view. FIG. 2 is an explanatory diagram illustrating a part of the evaluation device of FIG. 1 in plan view. FIG. 2 is an explanatory diagram illustrating an enlarged longitudinal cross-sectional view of unvulcanized rubber held in a holder in a preparation position. FIG. 3 is an explanatory diagram illustrating a process of moving unvulcanized rubber from a holder at a preparation position to a base table where it is heated, as seen from the front. FIG. 2 is an explanatory diagram illustrating, in a longitudinal cross-sectional view, a process of heating unvulcanized rubber to form a test body. FIG. 2 is an explanatory diagram illustrating a tensile process in which a tensile force is applied to a formed test specimen in a vertical cross-sectional view. FIG. 3 is an explanatory diagram illustrating, in a front view, a process of grasping the surface state of a predetermined area of the target surface after a tensioning process and a process of moving the test specimen to a holder at a storage position. FIG. 7 is an explanatory diagram illustrating a process of moving the holding arm to the holder in the preparation position as seen from the front. FIG. 2 is an explanatory diagram schematically illustrating changes over time in the surface state of a predetermined area of the target surface. FIG. 3 is a graph diagram illustrating a change over time in the amount of dirt deposited on the surface of a predetermined area of the target surface. FIG. 2 is a graph diagram illustrating the change over time in the fracture strength of the interface between the rubber and the target surface in a tensile process. It is an explanatory view illustrating a part of another embodiment of a mold releasability evaluation device in longitudinal cross-sectional view. FIG. 13 is an explanatory diagram illustrating, in a longitudinal cross-sectional view, the step of heating the unvulcanized rubber of FIG. 12 to form a test specimen. FIG. 14 is an explanatory diagram illustrating, in a vertical cross-sectional view, a tensile process for applying a tensile force to the test specimen in FIG. 13; FIG. 3 is an explanatory diagram illustrating an unvulcanized rubber insertion mechanism. FIG. 16 is an explanatory diagram illustrating a state in which unvulcanized rubber is accommodated and set in a cylindrical body by the insertion mechanism of FIG. 15; It is an explanatory view showing a modification of an unvulcanized rubber insertion mechanism. 18 is an explanatory diagram illustrating a state in which unvulcanized rubber is accommodated and set in a cylindrical body by the insertion mechanism of FIG. 17. FIG. FIG. 3 is an explanatory diagram illustrating a test specimen ejection mechanism. FIG. 20 is an explanatory diagram illustrating a state in which the test specimen is discharged and taken out from the cylindrical body by the discharge mechanism of FIG. 19; It is an explanatory view showing a modification of a test object ejection mechanism. FIG. 22 is an explanatory diagram illustrating a state in which the test specimen is discharged and taken out from the cylindrical body by the discharge mechanism of FIG. 21;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The rubber releasability evaluation method and apparatus of the present invention will be described below based on the embodiments shown in the drawings.

The embodiment of the rubber releasability evaluation apparatus 1 (hereinafter referred to as evaluation apparatus 1) illustrated in FIGS. 1 and 2 is a predetermined area of a flat target surface 8a of a base 8, and the position of this predetermined area is changed. The unvulcanized rubber 9A is repeatedly heated to form a large number of test pieces 9 made of vulcanized rubber. Further, a tensile process is performed in which each of the test specimens 9 thus formed is peeled off from a predetermined area of the target surface 8a. Then, after the tensile process of each test specimen 9, the range and amount of dirt X adhering to a predetermined area of the target surface 8a are obtained to grasp the surface condition. In the present invention, the test specimen 9 is not limited to completely vulcanized rubber, but includes rubber that is not completely vulcanized (so-called semi-vulcanized state). That is, the test specimen 9 may be a rubber in which elastic deformation is predominant, rather than a highly fluid state in which excessive plastic deformation occurs when a tensile force is applied in a tensile process to be described later. Note that the actuators 3 and 12, the measuring device 6, the surface grasping means 14, and the like are omitted and not shown in FIG.

This evaluation device 1 includes a base 8 having a flat target surface 8a, a heating mechanism 11 that heats unvulcanized rubber 9A to form a test specimen 9, and a tension mechanism that performs a tensile process on the test specimen 9. 2, a surface grasping means 14 for grasping the surface condition of a predetermined area of the target surface 8a, and a transport mechanism 4. In this embodiment, the target surface 8a is a metal surface. Furthermore, the evaluation device 1 includes a measuring device 6, a control section 15, and a calculation section 16, which measure the breaking strength F of the interface between the test specimen 9 and the target surface 8a (predetermined area) during the tensile process. A computer is used as the control section 15 and the calculation section 16.

This embodiment includes a holding block 8b that is detachably connected to the base 8. The holding block 8b has a through hole 8c extending vertically. This base stand 8 and holding block 8b function as a vulcanization mold.

Holders 5A and 5B are installed at a predetermined preparation position and a predetermined storage position, respectively, which are spaced apart from the position where the base 8 is installed. A large number of holding holes 5h are formed in the holders 5A and 5B, and one holder 5A holds the unvulcanized rubber 9A, and the other holder 5B holds the test specimen 9 after the tensile process.

In this embodiment, as illustrated in FIG. 3, unvulcanized rubber 9A is housed in a cylindrical body 10. Unvulcanized rubber 9A is arranged on the lower end opening 10b side of the cylindrical body 10, and a cylindrical pressure member 7 is inserted from the upper end opening 10a side. An engaging portion 10c is formed at the upper end of the cylindrical body 10, passing through the peripheral wall. The outer circumferential surface of the pressure member 7 is formed to be in close contact with the inner circumferential surface of the cylindrical body 10.

The cylindrical body 10 is not limited to a cylindrical shape, but can also have other shapes such as a rectangular cylindrical shape. The pressure member 7 is not limited to a cylindrical shape, but can also have another shape that matches the shape of the cylindrical body 10. The lower end surface of the pressure member 7 is a facing surface 7a facing the unvulcanized rubber 9A. The opposing surface 7a has a larger surface area than the opposing target surface 8a because it has many irregularities. That is, the opposing surface 7a is intentionally set to have a large contact area with the unvulcanized rubber 9A.

The size of the unvulcanized rubber 9A is, for example, approximately several cm in outer diameter and height (length, width, and height are several cm). The test specimen 9 formed by heating the unvulcanized rubber 9A also has approximately the same size as the unvulcanized rubber 9A. The state shown in FIG. 3 is achieved by inserting the unvulcanized rubber 9A from the lower end opening 10b of the cylindrical body 10 and inserting the pressure member 7 from the upper end opening 10a. The unvulcanized rubber 9A adheres to the inner peripheral surface and the opposing surface 7a of the cylindrical body 10 due to its adhesive properties.

The unvulcanized rubber 9A, the pressure member 7, and the cylindrical body 10 shown in FIG. 3 are in an upright state with the cylindrical body 10 inserted into the holding hole 5h of the holder 5A. A large number of these integrated objects are held in the holder 5A. Note that it is preferable to use a material or coating on the bottom surface of the holding hole 5h to prevent the unvulcanized rubber 9A from adhering.

After the tensile process, the test specimen 9, the pressure member 7, and the cylindrical body 10 are assembled into an upright state with the cylindrical body 10 inserted into the holding hole 5h of the holder 5B. A large number of these integrated objects are held in the holder 5B. Since vulcanized rubber (test specimen 9) does not have adhesive properties, there is no need to use any special material or coating on the bottom surface of the holding hole 5h of the holder 5B.

The transport mechanism 4 relatively moves the unvulcanized rubber 9A from a predetermined preparation position (holder 5A) to a predetermined area of the target surface 8a, and relatively moves the test specimen 9 from this predetermined area to a predetermined storage position (holder 5B). let The transport mechanism 4 includes guide rails 4a and 4b that extend orthogonally in the horizontal direction and a moving body 4c. The moving body 4c moves along one guide rail 4a, and the other guide rail 4b moves in the extending direction of the guide rail 4b with respect to the moving body 4c, and these movements are driven by a servo motor or the like. .

In this embodiment, an actuator 3, which will be described later, is connected to and suspended from the other guide rail 4b. The actuator 3 can be moved to any planar position by the transport mechanism 4. The operation of the transport mechanism 4 is controlled by a control section 15. The transport mechanism 4 is not limited to the configuration illustrated in this embodiment, but can adopt various configurations. For example, a robot arm or the like can be used as the transport mechanism 4.

The heating mechanism 11 heats the unvulcanized rubber 9A in a pressed state on a predetermined area of the target surface 8a to form the test body 9. The heating mechanism 11 includes an actuator 12 and a heating device 13. The rod 12a of the actuator 12 moves up and down, and the rod 12a that has advanced downward presses the upper end surface of the pressure member 7. As the actuator 12, various means can be used, such as a hydraulic cylinder, an air cylinder, a rod operated by a motor, and the like. The operation of the actuator 12 is controlled by a control section 15.

The heating device 13 heats the base 8 and the holding block 8b. Various means such as electricity and steam can be used for heating by the heating device 13. The heating device 13 vulcanizes or semi-vulcanizes the unvulcanized rubber 9A on the target surface 8a of the base 8, the opposing surface 7a of the pressure member 7, and the inner peripheral surface of the cylindrical body 10, which the unvulcanized rubber 9A contacts. It is heated to a predetermined heating temperature for vulcanization. The heating device 13 is controlled by a control section 15 . The heating device 13 is not limited to the specifications illustrated in this embodiment, and may have other specifications. For example, a heating device 13 that heats the entire or part of the evaluation apparatus 1 to the ambient temperature may be used. Specifically, the heating device 13 is equipped with a cover that covers the entire evaluation device 1, or a heating device 13 is equipped with a cover that covers a predetermined range of the evaluation device 1, and the inside of the cover is controlled by the control unit 15. It is also possible to control the ambient temperature within a desired temperature range.

The tensioning mechanism 2 applies a tensile force to the specimen 9 that attempts to peel the specimen 9 from the target surface 8a. Specifically, the tensile mechanism 2 applies a vertical tensile force to the entire contact surface of the test specimen 9 with the target surface 8a at once. The vertical direction in the present invention is a direction normal to the target surface 8a, but is substantially a direction of 90°±2° with respect to the target surface 8a, more preferably a direction of 90°±1°. Any direction is fine.

The tension mechanism 2 includes an actuator 3 and a holding arm 3c that is moved up and down by a rod 3a of the actuator 3. In this embodiment, a plate 3b is arranged below the rod 3a at a vertical interval, and the lower end of the rod 3a is connected to the upper plate 3b. A holding arm 3c is attached to the lower plate 3b. A measuring device 6 and an actuator 12 are sandwiched between the upper plate 3b and the lower plate 3b. Therefore, the holding arm 3c is connected to the rod 3a via the measuring device 6 and the actuator 12, which are sandwiched between the upper plate 3b and the lower plate 3b. The rod 12a of the actuator 12 passes through the lower plate 3b and can move up and down.

Two holding arms 3c are arranged at opposing positions, and the respective holding arms 3c are movable toward and away from each other. The number of holding arms 3c is not limited to two, but may be more than one, and may also be three, four, etc. The respective holding arms 3c are preferably arranged at equal intervals in the circumferential direction of a circle centered on the axis of the actuator 3. The operation of the actuator 3 and the holding arm 3c is controlled by a control section 15.

The measuring device 6 measures the fracture strength F at the interface with the target surface 8a of the test specimen 9 to which a tensile force is applied by the tensile mechanism 2. As the measuring device 6, for example, a load cell can be used. The breaking strength F of the interface between the test specimen 9 and the target surface 8a is basically the tensile strength (= tensile force/test specimen 9 and the target surface 8a). If the test piece 9 is damaged before the test piece 9 is peeled off from the target surface 8a, this breaking strength F is evaluated to be greater than the tensile strength when the test piece 9 is broken, or the test piece 9 is damaged. It can also be evaluated to be the same as the tensile strength when

The data measured by the measuring device 6 is input to the calculation section 16, and the above-mentioned breaking strength F is calculated by the calculation section 16. In this embodiment, the measuring device 6 is connected to the upper plate 3b and the actuator 12, but it can be installed at other positions as long as it can measure the breaking strength F mentioned above.

In this embodiment, a digital camera for acquiring image data is used as the surface grasping means 14. As the surface grasping means 14, it is also possible to use, for example, a height sensor that detects the thickness of the dirt X attached to the target surface 8a. The data acquired by the surface grasping means 14 is input to the calculation section 16.

The control unit 15 and devices controlled by the control unit 15 are communicably connected by wire or wirelessly, and the arithmetic unit 16 and devices that input data to the arithmetic unit 16 are communicably connected by wire or wirelessly. ing.

The material of the target surface 8a (base 8) can be the same (equivalent) metal as the actual vulcanizing mold, but for example, it is possible to set a reference material as an evaluation index in advance and use that reference material. do it. The material of the opposing surface 7a (pressing member 7) and the cylindrical body 10 may be the same as or different from that of the target surface 8a. In addition to the target surface 8a, various coating agents that cover the molding surface of the vulcanization mold can also be used. Alternatively, various vulcanized rubbers such as those used in vulcanizing bladders may be used as the target surface 8a.

Hereinafter, a method for evaluating the mold releasability of a test piece 9 made of vulcanized rubber using this evaluation apparatus 1 will be explained. Note that the evaluation procedure is the same when the test specimen 9 is semi-vulcanized rubber.

As illustrated in FIGS. 1 and 2, a cylindrical body 10 containing an unvulcanized rubber 9A and a pressure member 7 is prepared and placed upright in a holder 5A. Since a large number of test specimens 9 are to be formed, it is preferable to hold a large number of cylindrical bodies 10 containing the unvulcanized rubber 9A and the pressure member 7 in the holder 5A in advance.

Next, the moving mechanism 4 moves the holding arm 3c onto the cylindrical body 10 erected on the holder 5A, and then the rod 3a of the actuator 3 is advanced downward to move the holding arm 3c onto the cylindrical body 10. Move it down to the desired position. Next, the holding arms 3c are moved in a direction to approach each other, and each holding arm 3c is engaged with the engaging portion 10c of the cylindrical body 10.

Next, as illustrated in FIG. 4, the rod 3a of the actuator 3 is retreated upward to remove the cylindrical body 10 engaged with the holding arm 3c from the holder 5A. Further, the actuator 3 is moved toward the base 8 together with the cylindrical body 10 by the moving mechanism 4. After positioning the cylindrical body 10 above the through hole 8c of the holding block 8b, the rod 3a of the actuator 3 is advanced downward to insert the cylindrical body 10 into the through hole 8c, and the unvulcanized rubber 9A is targeted. It is placed on a predetermined area of the surface 8a. The base 8 and the holding block 8b are heated to a predetermined heating temperature by the heating device 13. Although the heating temperature can be set arbitrarily, it is set, for example, to 40°C or higher, and when assuming tire vulcanization conditions, it is set to about 150°C to 200°C.

Next, as illustrated in FIG. 5, the rod 12a of the actuator 12 is advanced downward to press the upper end surface of the pressure member 7. As a result, by sandwiching the unvulcanized rubber 9A between the base 8 and the pressure member 7 and bringing the base 8 and the pressure member 7 relatively close to each other, the unvulcanized rubber 9A is pressed. Heat. Although it varies depending on the size of the unvulcanized rubber 9A, the heating time of the unvulcanized rubber 9A is, for example, within 10 minutes.

After the predetermined heating time has elapsed, the rod 12a of the actuator 12 is retreated upward to release the pressure on the upper end surface of the pressure member 7. While the unvulcanized rubber 9A is being heated, the holding arm 3c and the engaging portion 10c of the cylindrical body 10 are kept engaged. Thereby, the unvulcanized rubber 9A can be heated more stably.

By heating the unvulcanized rubber 9A, a small piece of test specimen 9 made of vulcanized rubber that is in close contact without adhering to the target surface 8a is formed. Although the test body 9 is in close contact with the opposing surface 7a of the pressure member 7 and the inner peripheral surface of the cylindrical body 10 without being bonded, they may be bonded using an adhesive or the like. In this embodiment, since the opposing surface 7a is set to have a larger surface area than the target surface 8a, the test specimen 9 is in tighter contact with the opposing surface 7a than with the target surface 8a. In addition, since the contact area between the test specimen 9 and the inner peripheral surface of the cylindrical body 10 is larger than the contact area between the test specimen 9 and the target surface 8a, the test specimen 9 is stronger against the cylindrical body 10 than the target surface 8a. It's in close contact.

Next, as illustrated in FIG. 6, the rod 3a of the actuator 3 is retracted upward to move the holding arm 3c upward. As a result, a tensile process is performed in which the test specimen 9 is pulled upward together with the cylindrical body 10 and the pressure member 7.

As the tensile force applied to the test piece 9 gradually increases, the interface between the target surface 8a and the test piece 9 breaks (separates), so the tensile force at this time is measured by the measuring device 6. The value calculated by performing arithmetic processing in which the tensile force is divided by the contact area between the target surface 8a and the test specimen 9 by the calculation unit 16 is defined as the breaking strength F of the interface between the test specimen 9 and the target surface 8a.

That is, by moving at least one of the test specimen 9 and the base 8 in a direction away from each other, a vertical tensile force is applied at once to the entire contact surface of the test specimen 9 with the target surface 8a, The test specimen 9 is peeled off from a predetermined area of the target surface 8a. Since the test piece 9 made of vulcanized rubber adheres more tightly to the opposing surface 7a and the inner peripheral surface of the cylindrical body 10 than to the target surface 8a, the test piece 9 is basically peeled off at the target surface 8a.

In this embodiment, tensile force is applied to the specimen 9 by engaging the holding arm 3c with the engaging portion 10c and moving the cylindrical body 10 upward. Alternatively, an engagement part is provided at the upper end of the pressure member 7, and the holding arm 3c is engaged with the engagement part of the pressure member 7 and the engagement part 10c of the cylindrical body 10 to hold the pressure member 7. It is also possible to apply tensile force to the test specimen 9 by directly moving it upward.

By applying a vertical tensile force to the entire contact surface with the target surface 8a of the test specimen 9 at once, vulcanized rubber is the most difficult to release from the vulcanization mold in the actual manufacturing process of rubber products. The conditions are approximated. In tests in which adhesive strength is measured by peeling vulcanized rubber, the peel angle between the vulcanized rubber and the target surface tends to be unstable, making it difficult to measure adhesive strength while suppressing variations. On the other hand, in the present invention, the test piece 9 (vulcanized rubber) is not peeled, but a tensile force is applied to the test piece 9 as described above. Therefore, it is possible to stably measure the fracture strength of the interface between the test specimen 9 and the target surface 8a while suppressing variations.

Next, as illustrated in FIG. 7, the test specimen 9, which has been moved upward together with the cylindrical body 10 and pulled out from the through hole 8c, is moved toward the holder 5B by the moving mechanism 4. After positioning the cylindrical body 10 above the holding hole 5h of the holder 5B, the rod 3a of the actuator 3 is advanced downward to insert the cylindrical body 10 into the holding hole 5h. Thereby, the cylindrical body 10 is erected in the holding hole 5h, and the test specimen 9 is held by the holder 5B.

Further, after the test specimen 9 is pulled upward from the through hole 8c, the surface grasping means 14 is positioned above the through hole 8c by an appropriate means. Thereafter, the surface condition of a predetermined area of the target surface 8a is grasped by the surface grasping means 14.

The moving mechanism 4 that has moved the test specimen 9 to the holder 5B at the storage position moves the holding arm 3c toward the holder 5A at the preparation position, as illustrated in FIG. Thereafter, the engaging portion 10c of the cylindrical body 10 containing the newly heated unvulcanized rubber 9A is engaged with the holding arm 3c to form the above-mentioned test specimen 9 and the formed test specimen 9. The above-described tensile process is repeated.

That is, a large number of test bodies 9 are formed by repeating the series of processes from forming the test body 9 described above to completing the tensioning process in the same area without changing the position of the predetermined area. By repeating and continuously performing this series of steps, it is possible to easily reproduce the actual manufacturing process in which vulcanized rubber is repeatedly released from a vulcanization mold.

By forming a large number of test specimens 9, rubber components and components of compounding agents contained in the rubber gradually adhere to the target surface 8a and accumulate as dirt X. Therefore, when the surface condition of a predetermined area of the target surface 8a after the tensile process for each test specimen 9 is grasped by the surface grasping means 14, the surface condition is as shown in FIGS. 9(A) and 9(B). , (C). That is, the range of dirt X gradually widens (the amount V of dirt X accumulated gradually increases).

By calculating the change over time in the accumulated amount V of the dirt X by the calculation unit 16, the results illustrated in FIG. 10 can be obtained. Since the accumulation of dirt X is accelerated in a short period of time, it is possible to efficiently grasp the change over time in the releasability of the rubber forming the test specimen 9. The characteristics of the change over time in the amount of accumulated dirt This will be advantageous in determining the appropriate cleaning timing for vulcanization molds. It also greatly contributes to speeding up the development work of rubber compositions with improved mold release properties.

Further, by calculating the above-mentioned change over time in the breaking strength F using the calculation unit 16, the results illustrated in FIG. 11 can be obtained. This breaking strength F tends to increase as the accumulated amount V of dirt It can also be evaluated.

At the initial stage when the number of vulcanizations is small, it can be determined that the larger the breaking strength F is, the worse the mold releasability of the test specimen 9 is, and the smaller the breaking strength F is, the better the mold releasability is. On the other hand, if the change (increase) in the breaking strength F is small even when the number of vulcanizations increases, it can be evaluated that the change over time in the amount V of dirt X accumulated is small and the change in mold releasability is small. If the change (increase) in breaking strength F becomes excessive as the number of times of vulcanization increases, it can be evaluated that the change over time in the amount V of deposited dirt X is large and the change in mold releasability is large.

If the unvulcanized rubber 9A can be pressed against a predetermined area of the target surface 8a to form a small piece of test piece 9 that is in close contact with the target surface 8a without adhering, then The shaped body 10 and the holding block 8b can also be omitted. However, this pressure member 7 is used not only as a member to press the unvulcanized rubber 9A, but also by engaging the holding arm 3c with this pressure member 7 and moving it away from the base 8. It can also be used as a member for applying a tensile force to the test specimen 9 that is in close contact with (the opposing surface 7a) to perform the above-mentioned tensile process. When the cylindrical body 10 is omitted, the opposing surface 7a of the pressure member 7 is designed to have irregularities, so that the test specimen 9 is brought into closer contact with the opposing surface 7a than with the target surface 8a. Further, by using the cylindrical body 10, the test specimen 9 can be stably formed, and the tensile process can also be performed stably. Furthermore, by using the holding block 8b, the test specimen 9 can be formed more stably, and the tensile process can also be performed more stably.

The speed at which the tensile force is applied to the test specimen 9 can be the same (equivalent) to the actual speed at which the vulcanization mold is released from the actually vulcanized rubber product, but for example, the speed at which the tensile force is applied to the test specimen 9 can be the same (equivalent) to the actual speed at which the vulcanization mold is released from the vulcanized rubber product. It is sufficient to set a reference speed as an evaluation index within the range of .

Another embodiment of the evaluation device 1 illustrated in FIG. 12 differs from the previous embodiment in that the base 8 and the holding arm 3c are engaged with each other, and the unvulcanized rubber 9A held in the holder 5A is The base 8 is moved relative to the base. That is, the base 8 is moved to the position of each unvulcanized rubber 9A without moving the unvulcanized rubber 9A, and the test specimen 9 is formed and the tensile process is performed on each of the formed specimens 9. conduct. Other procedures are generally the same as in the previous embodiment.

A pressure member 7 is inserted into the cylindrical body 10 erected in the holder 5A from the lower end opening 10b side, and unvulcanized rubber 9A is accommodated at the upper end opening 10a side. The unvulcanized rubber 9A is housed in the cylindrical body 10 without protruding upward from the upper end opening 10a. The cylindrical body 10 and the pressure member 7 are detachably fixed to the holder 5A by screwing or the like. The base 8 is heated to a predetermined heating temperature by a heating device 13.

To form the test body 9, as illustrated in FIG. 13, the rod 12a of the actuator 12 is advanced downward to press the base 8 downward. Along with this, the target surface 8a of the base 8 presses the unvulcanized rubber 9A. Thereby, the unvulcanized rubber 9A is sandwiched between the base 8 and the pressure member 7, and the unvulcanized rubber 9A is heated while being pressed.

After the test specimen 9 is formed, as illustrated in FIG. 14, the rod 12a is retreated upward to release the pressure on the base 8. Then, the rod 3a of the actuator 3 is retreated upward, and the base 8 is moved upward by the holding arm 3c. As the base 8 moves upward, a vertical tensile force is applied at once to the entire contact surface of the test specimen 9 with the target surface 8a, and the test specimen 9 is peeled off from a predetermined area of the target surface 8a. . In this way, the tensile process is performed. A large number of test bodies 9 are formed by repeating a series of processes from the formation of the test body 9 to the completion of the tensile process by setting the predetermined area in the same area without changing the position.

Then, the surface condition of a predetermined area of the target surface 8a after the tensile process for each test specimen 9 is grasped by the surface grasping means 14. Furthermore, during the tensile process for each test piece 9, the breaking strength F of the interface between the test piece 9 and the target surface 8a is measured by the measuring device 6.

The evaluation apparatus 1 of the embodiment described above is provided with an insertion mechanism 17 for unvulcanized rubber 9A illustrated in FIGS. 15 to 18, and a discharge mechanism 21 for the test specimen 9 illustrated in FIGS. 19 to 22. You can also do that. The insertion mechanism 17 and the ejection mechanism 21 are controlled by the control section 15.

The insertion mechanism 17 illustrated in FIGS. 15 and 16 performs a housing process of housing the unvulcanized rubber 9A in the cylindrical body 10. This insertion mechanism 17 includes a rubber extruder 18 and a cutting tool 19. The rubber extruder 18 extrudes unvulcanized rubber 9A from its tip opening. In this embodiment, the rubber extruder 18 has a fluid cylinder connected to the pipe section 18a, and the unvulcanized rubber 9A filled inside the pipe section 18a is moved through the tip opening of the pipe section 18a by the cylinder rod. being pushed out. The cutting tool 19 has a cutting blade 19a that moves back and forth across the front of the opening at the tip of the pipe portion 18a.

As illustrated in FIG. 15, the cylindrical body 10 into which the pressure member 7 is inserted is suspended together with the pressure member 7 by the holding arm 3c, and the moving mechanism 4 is used to place the cylindrical body 10 above the pipe portion 18a of the rubber extruder 18. Move it to position it. The unvulcanized rubber 9A is not yet accommodated in this cylindrical body 10. Next, the rod 3a of the actuator 3 is advanced downward to place the cylindrical body 10 on the tip of the pipe portion 18a. The movement of the cylindrical body 10 and the pressure member 7 is restricted by the holding arm 3c and the rod 12a of the actuator 12 so that they do not move upward. The inner diameter of the cylindrical body 10 is set larger than the inner diameter of the pipe portion 18a and smaller than the outer diameter of the pipe portion 18a.

Next, the cylinder rod of the extruder 18 is advanced, and the unvulcanized rubber 9A is pushed from the tip opening of the pipe portion 18a toward the lower end opening of the cylindrical body 10, so that a predetermined amount of unvulcanized rubber is placed inside the cylindrical body 10. Fill with vulcanized rubber 9A. The filled unvulcanized rubber 9A is in close contact with the inner peripheral surface and the lower end surface of the pressure member 7 at the lower end of the cylindrical body 10.

Next, as illustrated in FIG. 16, the cylindrical body 10 is slightly moved upward, and the cutting blade 19a is inserted between the lower end surface of the cylindrical body 10 and the distal end surface of the pipe portion 18a to cut the unvulcanized rubber. Cut 9A. Through this accommodation process, the unvulcanized rubber 9A is accommodated in the cylindrical body 10 as illustrated in FIG. This unvulcanized rubber 9A is conveyed to the holder 5A or a predetermined area of the target surface 8a.

It is also possible to use the insertion mechanism 17 illustrated in FIGS. 17 and 18. The insertion mechanism 17 includes a cylindrical body 20 having a cutting blade 20a at the lower end, and an actuator 3 that moves the cylindrical body 20a up and down. As the cylindrical body 20, the previously described cylindrical body 10 is used, and an annular cutting blade 20a is formed at the lower end.

As illustrated in FIG. 17, the cylindrical body 10 into which the pressure member 7 is inserted is suspended together with the pressure member 7 by the holding arm 3c, and the moving mechanism 4 is placed on the sheet-like unvulcanized rubber 9A. Move it to position it. The unvulcanized rubber 9A is not yet accommodated in this cylindrical body 10. Next, the rod 3a of the actuator 3 is advanced downward to move the cylindrical body 10 and the pressure member 7 downward integrally. The movement of the cylindrical body 10 and the pressure member 7 is restricted by the holding arm 3c and the rod 12a of the actuator 12 so that they do not move upward.

The cutting blade 20a moving downward punches out the sheet-like unvulcanized rubber 9A, and pushes the unvulcanized rubber 9A toward the lower end opening of the cylindrical body 10, thereby inserting a predetermined amount of unvulcanized rubber into the inside of the cylindrical body 10. Fill with sulfur rubber 9A. The filled unvulcanized rubber 9A is in close contact with the inner peripheral surface and the lower end surface of the pressure member 7 at the lower end of the cylindrical body 10.

Next, as illustrated in FIG. 18, the cylindrical body 10 is moved upward. Through this accommodation process, the unvulcanized rubber 9A is accommodated in the cylindrical body 10 as illustrated in FIG. This unvulcanized rubber 9A is conveyed to the holder 5A or a predetermined area of the target surface 8a. Note that, unlike this embodiment, it is also possible to punch out a predetermined amount of unvulcanized rubber 9A using a dedicated cylindrical body 20 different from the cylindrical body 10. In this case, the work of storing the punched unvulcanized rubber 9A from the cylindrical body 20 into the cylindrical body 10 is performed.

The discharge mechanism 21 illustrated in FIGS. 19 and 20 performs a discharge process of discharging the test specimen 9 to the outside of the cylindrical body 10 after the tensile process has been performed. This discharge mechanism 21 includes a discharge table 22 in which a through hole 22a is formed, a separator 23, and an actuator 12 that presses the pressure member 7. The diameter of the through hole 22a is set larger than the inner diameter of the cylindrical body 10 and smaller than its outer diameter. The separator 23 separates the test specimen 9 from the pressurizing member 7 . In this embodiment, the separator 23 has a cutting blade 23a that moves forward and backward across the lower end opening of the through hole 22a.

As illustrated in FIG. 19, the cylindrical body 10 housing the test specimen 9 together with the pressure member 7 is suspended by the holding arm 3c, and is moved and positioned over the through hole 22a by the moving mechanism 4. . The test specimen 9 housed in the cylindrical body 10 together with the pressure member 7 is transported from the holder 5B or from a predetermined area on the target surface 8a.

Next, the rod 3a of the actuator 3 is advanced downward to place the cylindrical body 10 on the top plate of the discharge table 22. The movement of the cylindrical body 10 is restricted by the holding arm 3c so that it does not move up and down. Next, the rod 12a is advanced to push the pressure member 7 and the test specimen 9 toward the lower end opening of the cylindrical body 10, so that the test specimen 9 that has passed through the through hole 22a protrudes below the through hole 22a. .

Next, as illustrated in FIG. 20, a cutting blade 23a is inserted between the lower end surface of the pressure member 7 and the test specimen 9 to separate the test specimen 9 from the pressure member 7. The test specimen 9 falls below the discharge table 22. Through this discharge process, the test specimen 9 is discharged to the outside of the cylindrical body 10. The cylindrical body 10 from which the test specimen 9 has been taken out and the pressure member 7 are transported to a predetermined storage location.

The separator 23 is not limited to the one illustrated in this embodiment, and various other mechanisms can be used. For example, it is also possible to use a mechanism in which a rod-shaped body is inserted into the test body 9 that projects below the through hole 22a and the test body 9 is peeled off from the pressure member 7. Alternatively, with the test specimen 9 protruding below the through hole 22a, at least one of the discharge table 22 and the cylindrical body 10 is slid in the lateral direction to apply shear force to the test specimen 9, and the pressurizing member A mechanism for separating it from 7 can also be used.

It is also possible to use the ejection mechanism 21 illustrated in FIGS. 21 and 22. The insertion mechanism 21 includes an ejection table 22 in which a through hole 22a is formed and an actuator 12 that presses the pressure member 7.

As illustrated in FIG. 21, the cylindrical body 10 housing the test specimen 9 together with the pressure member 7 is suspended by the holding arm 3c, and is moved and positioned above the through hole 22a by the moving mechanism 4. . Next, the rod 3a of the actuator 3 is advanced downward to place the cylindrical body 10 on the top plate of the discharge table 22. The movement of the cylindrical body 10 is restricted by the holding arm 3c so that it does not move.

Next, the rod 12a is advanced to push the pressurizing member 7 and the test specimen 9 toward the lower end opening of the cylindrical body 10, so that they pass through the through hole 22a. Thereby, as illustrated in FIG. 22, the test specimen 9 is discharged to the outside of the cylindrical body 10 while being integrated with the pressure member 7.
The test specimen 9 falls below the discharge table 22. The cylindrical body 10 from which the test specimen 9 and the pressure member 7 have been taken out is transported to a predetermined storage location.

According to this ejection mechanism 21, the test specimen 9 is integrated with the pressure member 7, so it is preferable to attach an information display such as a mark or a number to the pressure member 7 indicating the specifications of the test specimen 9. . This is extremely advantageous in managing the specifications of the test specimen 9 without error.

In the embodiment described above, the cylindrical body 10 (test body 9) is moved up and down by operating the actuator 3 with respect to the fixed discharge table 22, but the cylindrical body 10 (test body 9) is moved up and down when The discharge table 22 can also be moved up and down with respect to the cylindrical body 10 (test body 9). That is, at least one of the actuator 3 (holding arm 3c) and the discharge table 22 may be moved up and down to approach and separate from each other.

By adding the above-mentioned insertion mechanism 17 and ejection mechanism 21 to the evaluation device 1, the above-mentioned accommodation process, a series of processes from the formation of the test specimen 9 to the completion of the tension process, and the above-mentioned ejection process are completed. The entire process can be automated and continuously performed under the control of the control unit 15. Accordingly, it becomes possible to minimize human work when performing peelability evaluation. In addition, since it is possible to repeat and continuously perform the entire process described above, it is possible to significantly shorten the time required to evaluate the releasability of a large number of test specimens 9 and test specimens 9 of various rubber types. become.

1 Evaluation device 2 Tension mechanism 3 Actuator 3a Rod 3b Plate 3c Holding arm 4 Transport mechanism 4a, 4b Guide rail 4c Moving body 5A, 5B Holder 5h Holding hole 6 Measuring device (load cell)
7 Pressure member 7a Opposing surface 8 Base stand 8a Flat target surface 8b Holding block 8c Through hole 9 Test body 9A Unvulcanized rubber 10 Cylindrical body 10a Upper end opening 10b Lower end opening 10c Engagement part 11 Heating mechanism 12 Actuator 12a Rod 13 Heating machine 14 Surface grasping means 15 Control section 16 Computing section 17 Insertion mechanism 18 Rubber extruder 18a Pipe section 19 Cutting tool 19a Cutting blade 20 Cylindrical body 20a Cutting blade 21 Discharge mechanism 22 Discharge table 22a Through hole 23 Separator 23a Cutting Blade X dirt

Claims (7)

Testing of a small piece of vulcanized or semi-vulcanized rubber that is in close contact with the target surface without adhesion by pressing unvulcanized rubber onto a predetermined area of the flat target surface of the base and heating it. After forming the body, by moving at least one of the test body and the base in a direction away from each other, a tensile force in the vertical direction is applied to the entire contact surface of the test body with the target surface at once. A tensile process is performed in which the test specimen is peeled from the predetermined area by applying a tensile force, and a series of processes from the formation of the test specimen to the completion of the tensile process are set in the same area without changing the position of the predetermined area. A method for evaluating mold releasability of rubber, characterized in that a large number of test specimens are formed by repeatedly performing the above-mentioned test specimens, and the surface state of the predetermined area of each specimen is determined after the tensile process. The method for evaluating mold releasability of rubber according to claim 1, wherein the breaking strength of the interface between the test body and the target surface is measured during the tensile step for each of the test bodies. Heating the unvulcanized rubber in a pressed state by sandwiching the unvulcanized rubber between the base and a metal pressure member and bringing the base and the pressure member relatively close to each other. forming the test specimen that is in closer contact with or adhering to the pressure member than the target surface of the base, and relatively separating the base and the pressure member; The method for evaluating mold releasability of rubber according to claim 1 or 2, wherein the tensile step is performed in a step. Storing the unvulcanized rubber in a metal cylindrical body, arranging the base on one opening side of the cylindrical body, and inserting the pressure member into the cylindrical body from the other opening side. According to another aspect of the present invention, the test specimen is formed by sandwiching the unvulcanized rubber between the base and the pressure member, and the tensile step is performed with the test specimen housed in the cylindrical body. 3. The method for evaluating mold releasability of rubber as described in 3. 4. A holding block having a vertically penetrating through hole is connected to the base, and the test specimen is formed with the cylindrical body inserted into the through hole, and the tensioning step is performed. Rubber mold releasability evaluation method described in . The unvulcanized rubber is accommodated in the cylindrical body using an insertion mechanism, the test specimen after the tensioning step is discharged to the outside of the cylindrical body using a discharge mechanism, and the insertion mechanism controlling the entire process consisting of a step of housing the unvulcanized rubber in the cylindrical body by a method, a series of steps, and a step of discharging the test specimen to the outside of the cylindrical body by the discharge mechanism. 6. The method for evaluating mold releasability of rubber according to claim 4, wherein the method is carried out under control. A base having a flat target surface, and a vulcanized rubber or semi-vulcanized rubber that is heated while pressing unvulcanized rubber onto a predetermined area of the target surface so as to be in close contact with the target surface without adhering. a heating mechanism for forming a test piece of a small piece; a tensile mechanism that performs a tensile process of peeling the test specimen from the predetermined area by applying a tensile force in a vertical direction to the entire contact surface at once; a surface grasping means that grasps the surface condition of the predetermined area; A transport mechanism that relatively moves the unvulcanized rubber from a predetermined preparation position to the predetermined area, and relatively moves the test specimen from the predetermined area to a predetermined storage position,
The series of processes from the formation of the test specimen to the completion of the tensioning process is repeated in the same area without changing the position of the predetermined area, and the tensioning process is performed for each of the large number of test specimens formed. An apparatus for evaluating mold releasability of rubber, characterized in that the subsequent surface state of the predetermined area is grasped by the surface grasping means.

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