JP5674028B2 - Conveyor belt impact test apparatus and method - Google Patents

Description

  The present invention relates to an impact test apparatus and method for a conveyor belt, and more particularly, an impact test apparatus for a conveyor belt capable of quickly and accurately evaluating impact resistance by repeatedly dropping weights at a constant period and It is about the method.

  The conveyor belt is subjected to an impact force by the dropped transported object. For this reason, repeated dropping of the object to be conveyed causes damage to the core body (canvas, steel cord, etc.) and cover rubber constituting the conveyor belt. When the weight of the conveyed object is large or the dropped height is large, the core body may be cut.

  Assuming such a problem, an impact test is performed on the conveyor belt. In a conventional impact test, for example, after repeatedly dropping a weight on a conveyor belt test piece placed on a cradle, the residual tensile strength of the core of the test piece is measured to determine the impact resistance. Is evaluated. However, in the conventional conveyor belt impact test, the free-falling weight collides with the test specimen and then bounces upward, so that a so-called double strike occurs in which it collides with the test specimen again. The impact at the second hit is different from the first impact set at a constant value and varies. Therefore, in order to grasp the impact resistance accurately, it is necessary to prevent double strikes.

  Although a conveyor belt is not an object to be evaluated, a method has also been proposed in which impact resistance is evaluated by allowing an object to be evaluated to fall freely and collide with a landing surface (see Patent Document 1). The testing machine described in Patent Document 1 is provided with a rebound prevention means for preventing rebound (double strike) of the evaluation object that has jumped up (see paragraphs 0021 to 0024, FIG. 9, FIG. 10, etc.). . However, there is a problem that it takes time to repeatedly drop the evaluation object captured by the rebound prevention means from the initial height (see paragraphs 0032 to 0033).

JP 2006-200991 A

  An object of the present invention is to provide an impact test apparatus and method for a conveyor belt capable of quickly and accurately evaluating impact resistance by dropping weights repeatedly at a constant period.

  In order to achieve the above object, an impact test apparatus for a conveyor belt according to the present invention includes a main body frame having a guide groove extending in the vertical direction, a weight that freely guides the guide groove and falls along the main body frame. An annular body erected in the vertical direction, a rack attached to each of the positions in which the circumferential length of the annular body is divided in two, and capable of holding the weight, and an upper end portion of the annular body of the main body frame, A holding release member provided at a position and a posture correcting mechanism for correcting the weight in a direction along the guide groove, and rotationally drive the annular body while holding the weight in one rack. Thus, the weight is moved upward to a predetermined position, and the weight is pushed forward by the holding release member at the position to release from holding the rack, and the weight is guided by the posture correcting mechanism. The weight, which is free-falling while correcting the posture in the direction along the axis, and colliding with the test piece of the conveyor belt arranged at the position where the weight is dropped, is moved below the weight by the rotationally driven annular body. The other rack is configured to be held at a timing that does not re-collision with the test body, and is moved upward to a predetermined position so that the free fall of the weight is repeated.

  Here, the holding release member protrudes forward from the main body frame and is pushed forward while holding the weight from above and below by the upward moving rack holding the weight and the holding release member, thereby releasing the weight from the rack holding. It can also be set as the structure to do. For example, the lower surface of the holding release member is configured to be inclined forwardly and upwardly by 5 ° to 80 ° with respect to the horizontal. The posture correction mechanism, a rod-like body that can be moved up and down along the guide groove, and a biasing member that is attached to the rod-like body and biases the weight toward the main body frame. . The lower end portion of the weight can be formed in a wedge shape, and the cutting edge direction of the lower end portion can be adjusted.

  Further, the impact test method for a conveyor belt according to the present invention is provided with a rack at each of the positions where the circumferential length of the annular body installed in the vertical direction is divided into two parts, with a weight held in one rack, By rotating and driving the annular body, the weight is moved upward to a predetermined position, and then the weight is pushed forward by the holding release member to release the rack from being held, and the body frame is extended vertically. The conveyor belt placed at the falling position of the weight is tested by allowing the weight to freely fall by being guided by the guide groove, and at that time the posture is corrected in the direction along the guide groove by the posture correction mechanism. Collision with the body, and after the collision, the weight that jumps up is held by the other rack that has been moved below the weight by the rotationally driven annular body at a timing that does not re-collision with the specimen. And in the state, by upward movement of the weight to a predetermined position by the annular body continuously rotated, characterized in that to repeat the free fall of the weight.

  Here, when the holding release member protrudes forward from the main body frame and the weight held on the rack is moved upward to a predetermined position, the weight is moved from above and below by the rack and the holding release member that move upward. The weight can also be released from holding the rack by pushing forward while pinching. The posture correcting mechanism is configured by a rod-like body that is movably fitted along the guide groove, and a biasing member that is attached to the rod-like body and biases the weight toward the main body frame. Push the weight forward against the biasing force of the member, release the weight from holding the rack, and then free the posture by correcting the posture in the direction along the guide groove by the biasing force of the biasing member You can also.

  According to the present invention, by rotating the annular body while holding the weight in one rack, the weight is moved upward to a predetermined position, and the weight is pushed forward by the holding release member at that position. The rack is released from holding, and is guided by a guide groove extending in the vertical direction on the main body frame to allow the weight to fall freely. At that time, the posture is corrected in the direction along the guide groove by the posture correction mechanism. Therefore, the weight can be made to collide with the conveyor belt specimen in a constant posture at all times. Thereby, the dispersion | variation in the magnitude | size of the impact force given to a test body can be suppressed.

  In addition, the weight that has collided with the test body and jumped up is held at a predetermined position in a state where it is held by the other rack that has been moved below the weight by a rotationally driven annular body at a timing that does not re-collision with the test body. Thus, the weight can be repeatedly dropped freely, so that it is possible to evaluate the impact resistance quickly and accurately by repeatedly dropping the weight at a constant period while preventing double hitting.

  Furthermore, since the posture of the weight is corrected by the posture correction mechanism and collides with the test body in the same posture, the direction in which the weight jumps up does not vary and becomes a constant direction. For this reason, it becomes difficult to cause a problem of failing to hold the jumped weight with the other rack, which is more advantageous for quick evaluation.

1 is a side view illustrating an overall outline of an impact test apparatus for a conveyor belt according to the present invention. It is a front view which illustrates the impact test apparatus of FIG. It is a front view which illustrates a weight and a posture correction mechanism. It is a side view which illustrates a weight and a posture correction mechanism. It is explanatory drawing which illustrates the state which cancels | releases a weight from holding | maintenance of a rack. It is explanatory drawing which illustrates the state which is making the weight fall freely. It is explanatory drawing which illustrates the state which the weight collided with the test body. It is a side view which shows the modification of a rack.

  Hereinafter, the conveyor belt impact test apparatus and method of the present invention will be described with reference to the embodiments shown in the drawings.

  As illustrated in FIGS. 1 to 4, a conveyor belt impact test apparatus 1 (hereinafter referred to as a “test apparatus 1”) according to the present invention includes a main body frame 1 erected from a flat base 2 a and a free-falling weight 6. And an annular body 4 erected in the vertical direction along the main body frame 2, two racks 3 a and 3 b attached to the annular body 4, a holding release member 2 c, and a posture correcting mechanism 7.

  In this embodiment, a fixing holder 8, a tension holding mechanism 9 and a support 10 for installing a conveyor belt test body CV (hereinafter referred to as a test body CV) are further provided. The tension holding mechanism 9 stretches and fixes the core body C with a predetermined tension T so as to wind the core body C around the winding shaft.

  The main body frame 2 has two guide grooves 2b extending in the vertical direction on the front surface thereof. A holding release member 2c is attached at a position corresponding to the upper end of each guide groove 2b. The guide groove 2b can be single.

  The holding release member 2c functions to remove the weight 6 from the racks 3a and 3b holding the weight 6, and the lower surface of the holding release member 2c becomes an inclined surface inclined upward toward the front in a side view. Yes. The holding release member 2 is not limited to the shape exemplified in the embodiment, but if the shape has such an inclined surface, the weight 6 can be easily pushed forward from the racks 3a and 3b, and the weight 6 can be smoothly moved from the racks 3a and 3b. It is advantageous to release the holding. For example, the lower surface of the holding release member 2 is inclined forward and upward at an angle of 5 ° to 80 ° with respect to the horizontal.

  On both side surfaces of the main body frame 2, a driving pulley 5 a and a driven pulley 5 b are installed at the lower end. An annular body 4 is bridged between the drive pulley 5a and the driven pulley 5b. For example, a transmission chain or a transmission belt is used as the annular body 4. The drive pulley 5a is rotationally driven by the drive motor 5 via a transmission member. Accordingly, the annular body 4 installed in the vertical direction is rotationally driven by the drive motor 5 between the drive pulley 5a and the driven pulley 5b. The holding release member 2 c is located in the vicinity of the upper end portion of the driven pulley 5 b, that is, in the vicinity of the upper end portion of the annular body 4 installed on the main body frame 2.

  Racks 3 a and 3 b are attached to the respective annular bodies 4 at positions where the circumferential length is divided into two. That is, the interval between the rack 3 a and the rack 3 b is half of the circumferential length of the annular body 4. The racks 3a and 3b of this embodiment are inclined surfaces in which the surface on which the weight 6 is placed is inclined slightly downward toward the front in a side view.

  The weight 6 is disposed to face the front surface of the main body frame 2 in which the guide groove 2b is formed, and the lower end portion 6a thereof is formed in a wedge shape. The cutting edge direction of the lower end portion 6a can be set as appropriate. For example, the lower end portion 6a can be movable with respect to the main body of the weight 6 so that the cutting edge direction can be adjusted. The cutting edge angle (cutting edge shape) of the lower end portion 6a can be set as appropriate, and the cutting edge shape can be changed.

  The weight 6 has columnar holding portions 6b extending in the lateral direction on both side surfaces. The weight 6 is held by the holding portion 6b being placed on the racks 3a and 3b. The shape of the holding portion 6b is not limited to a columnar shape, but if the portions that come into contact with the racks 3a and 3b are formed in an arc shape, the weight 6 can be easily held and released from the held racks 3a and 3b. Even if the holding portion 6b is a rotating roller, the weight 6 can be easily released from the racks 3a and 3b.

  The posture correction mechanism 7 functions to correct the posture of the weight 6, and includes a bolt 7a penetrating the weight 6 in the front-rear direction, a nut 7b screwed into the bolt 7a, and a spring in which the bolt 7a is inserted. 7c. A nut 7b that is screwed to the tip end of the bolt 7a is movably fitted in the guide groove 2b. Thereby, the bolt 7a of the rod-shaped body is in a state of being fitted so as to be vertically movable along the guide groove 2b.

  The spring 7 c is disposed between the head of the bolt 7 a and the weight 6, and biases the weight 6 toward the main body frame 2. Instead of the spring 7a, another urging member such as a rubber bush may be used.

  The posture correction mechanism 7 is not limited to the one exemplified in this embodiment as long as the free-falling weight 6 can correct the posture in the direction along the guide groove 2b. That is, any mechanism may be used as long as the posture can be corrected so that the vertical direction of the free-falling weight 6 is parallel to the extending direction (vertical direction) of the guide groove 2b.

  In the test apparatus 1 of the present invention, the weight 6 held in one rack 3a is freely dropped from a predetermined height, and the weight jumped up by colliding with the test body CV is captured by the other rack 3b without being hit twice. The weight 6 is held and moved upward to a predetermined height, and the free fall of the weight 6 is repeated. An example of a conveyor belt impact test method using the test apparatus 1 is as follows.

  The test body CV includes a plurality of core bodies C (steel cords) juxtaposed in the belt width direction and a cover rubber provided so as to sandwich the top and bottom of the core body C. Depending on the specifications of the conveyor belt, other reinforcing members and the like are embedded in the cover rubber. The core body C may be a canvas formed of various fiber cords in addition to the steel cord.

  The core C is exposed in the longitudinal direction of the belt from both ends of the test body CV, one end is fixed by a fixing holder 8 such as a clamp, and the other end is held by a tension holding mechanism 9. Then, the lower surface of the test body CV is supported by the support 10 and is stretched at the dropping position of the weight 6 with a preset tension T. The tension T of the core C is set to the same tension as the use condition at the site, and the interval between the two support tools 10 is set to the same interval as the interval between the support rollers at the site. The arcuate radius of the upper surface of the support 10 is preferably the same as the radius of the support roller in the field. The impact test can also be performed by placing the support 10 at the falling position of the weight 6. The height at which the weight 6 is freely dropped is set to be, for example, the same as the input height at which the object to be conveyed is input to the conveyor belt at the site.

  After setting the test body CV, as illustrated in FIGS. 1 and 2, the holding portion 6 b is placed on one rack 3 a to hold the weight 6. Then, the weight 6 is moved upward by rotationally driving the annular body 4. At this time, the weight 6 is in a state along the guide groove 2b.

  As illustrated in FIG. 5, when the weight 6 is moved upward to a predetermined position, the holding portion 6b comes into contact with the holding release member 2c. Since the annular body 4 is rotationally driven as it is, the weight 6 (holding portion 6b) is pushed forward by the holding release member 2c and the rack 3a moving upward while being sandwiched from above and below. At this time, the weight 6 is pushed forward against the urging force of the spring 7c, and released from the holding of the rack 3a in a posture inclined forward.

  Thereafter, the weight 6 pushed out from the top of the rack 3a is guided by the guide groove 2b as shown in FIG. At that time, the weight 6 tilted forward is corrected in posture by the posture correction mechanism 7. That is, the weight 6 is corrected in the direction along the guide groove 2b by the urging force of the spring 7c and freely falls.

  As illustrated in FIG. 7, the free-falling weight 6 collides with the specimen CV set at the dropping position. The holding part 6b of the weight 6 that collides with the test body CV and jumps up is captured at a timing at which it does not re-collision with the test body CV by the other rack 3b that has been moved below the weight 6 by the annular body 4 that is rotationally driven. , Retained. Thus, the weight 6 held by the other rack 3b is again moved upward as illustrated in FIG. Next, the weight 6 is similarly released from the holding of the rack 3b at a predetermined position as illustrated in FIG.

  By continuing to rotate the annular body 4, the weight 6 is repeatedly dropped at a constant cycle to perform an impact test. The rotational drive speed of the annular body 4 is set so that the jumped weight 6 can be captured and held by the racks 3a and 3b at a timing that does not re-impact with the test body CV.

  In the present invention, when the weight 6 is guided in the guide groove 2b and freely dropped, the posture correction mechanism 7 corrects the posture in the direction along the guide groove 2b. Can collide with CV. Thereby, the variation in the magnitude of the impact force applied to the specimen CV is suppressed, which is advantageous for acquiring impact resistance data with high accuracy.

  Further, the weight 6 that has collided with the test body CV and jumped up is moved upward with the other rack that has moved below the weight 6 being held at a timing not to re-collision with the test body CV. Since the 6 free fall is repeated, the weight 6 can be repeatedly dropped at a constant period while preventing double hitting, and the impact resistance of the specimen CV can be evaluated quickly and accurately.

  Furthermore, since the posture of the weight 6 is corrected by the posture correction mechanism 7 and collides with the specimen CV in the same posture, the weight 6 jumps up in a certain direction. If the jumping direction varies, the holding portion 6b of the weight 6 cannot be captured by the racks 3a and 3b, and the test must be interrupted. However, in the present invention, such a problem can be avoided, so that it is more and more advantageous for quickly evaluating the impact resistance of the test body CV.

  As illustrated in FIG. 8, the upper surfaces of the racks 3 a and 3 b can be inclined in two steps. As described above, when the inclination angle is made larger on the front inclined surface than on the rear inclined surface, the weight 6 is smoothly pushed out from the racks 3a and 3b, so that the holding can be easily released, and the weight 6 can be freely and repeatedly dropped without delay. This is advantageous.

  In this embodiment, the cutting edge direction of the tip portion 6a of the weight 6 is set to be orthogonal (90 °) to the longitudinal direction (stretching direction) of the core body C, but the cutting edge direction can be set as appropriate. it can. For example, the cutting edge direction can be set to be parallel (0 °) to the longitudinal direction of the core or to be a desired angle in the range of 0 ° to 90 °.

  Further, by changing the mass of the weight 6 and the height at which the weight 6 is released from the holding of the racks 3a and 3b, the impact force applied to the specimen CV can be adjusted.

DESCRIPTION OF SYMBOLS 1 Test apparatus 2 Main body frame 2a Base 2b Guide groove 2c Holding release member 3a, 3b Rack 4 Ring body 5 Drive motor 5a Drive pulley 5b Driven pulley 6 Weight 6a Tip part 6b Holding part 7 Posture correction mechanism 7a Bolt 7b Spring 7c Nut 8 Fixed holding tool 9 Tension holding mechanism 10 Support tool CV Specimen C Heart body

Claims (8)

A main body frame having a guide groove extending in the vertical direction, a weight that is guided by the guide groove and freely falls, an annular body that is installed in the vertical direction along the main body frame, and a circumferential direction of the annular body A rack which is attached to each of the positions where the length is divided into two and can hold the weight, a holding release member provided at a position which becomes an upper end portion of the annular body of the main body frame, and the weight as a guide groove With a posture correction mechanism that corrects the posture in the direction along,
By rotating the annular body while holding the weight in one rack, the weight is moved upward to a predetermined position, and the weight is pushed forward by the holding release member at that position to hold the rack. The weight is free to fall while the posture is corrected in the direction along the guide groove by the posture correction mechanism, and the weight jumped up by colliding with the test piece of the conveyor belt arranged at the weight drop position is rotated. The other rack that has moved below the weight by the driven annular body is held at a timing that does not re-collision with the test body and is moved upward to a predetermined position so that the free fall of the weight is repeated. Conveyor belt impact test device, characterized in that it is configured as described above.   The holding release member protrudes forward from the main body frame, and is configured to release the weight from holding the rack by pushing the weight forward while sandwiching the weight from above and below by the upwardly moving rack holding the weight and the holding release member. The impact test apparatus for a conveyor belt according to claim 1.   The impact test apparatus for a conveyor belt according to claim 2, wherein a lower surface of the holding release member is inclined forwardly and upwardly by 5 ° to 80 ° with respect to the horizontal.   2. The posture correcting mechanism is configured by a rod-like body that is fitted so as to be vertically movable along the guide groove, and a biasing member that is attached to the rod-like body and biases a weight toward a main body frame. The impact test apparatus for a conveyor belt according to any one of?   The impact test apparatus for a conveyor belt according to any one of claims 1 to 4, wherein a lower end portion of the weight is formed in a wedge shape, and a cutting edge direction of the lower end portion is adjustable.   A rack is provided at each position where the circumferential length of the annular body installed in the vertical direction is divided into two parts, and the weight is held in one of the racks. Next, the weight is pushed forward by the holding release member at that position to release the rack from holding, and the weight is freely dropped by being guided by the guide groove extending vertically in the main body frame. At that time, the posture is corrected in the direction along the guide groove by the posture correction mechanism, and is collided with the test body of the conveyor belt arranged at the falling position of the weight. With the other rack that has been moved below the weight by the rotationally driven annular body, the weight is moved upward to a predetermined position while being held at a timing that does not collide with the specimen. Wherein by the annular body continuously rotated, impact test method of the conveyor belt, characterized in that it has to repeat the free fall of the weight.   The holding release member protrudes forward from the main body frame, and when the weight held on the rack is moved upward to a predetermined position, the weight is sandwiched from above and below by the rack moving upward and the holding release member. The impact test method for a conveyor belt according to claim 6, wherein the weight is released from holding the rack.   The posture correcting mechanism is configured by a rod-like body that is movably fitted along the guide groove, and a biasing member that is attached to the rod-like body and biases the weight toward the main body frame. Push the weight forward against the biasing force of the member, release the weight from holding the rack, and then free the posture by correcting the posture in the direction along the guide groove by the biasing force of the biasing member The impact test method for a conveyor belt according to claim 6 or 7.

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