Conveyor

Abstract

The conveying device (200) includes a plurality of carriers (100) that are independently driven and controlled by a linear motor and travel on the same rail (201) to convey an object (300). The carriers (100) include a carrier body (1) that holds the object (300) and travels along the rail (201), and a buffer mechanism (4) that is attached to the carrier body (1) and absorbs the impact force when adjacent carriers (100) collide with each other. The buffer mechanism (4) includes a buffer protrusion (5) that protrudes toward the carrier (100) located in front, and a buffer receiving portion (6) that receives the buffer protrusion (5) of the carrier (100) traveling behind. The buffer receiving portion (6) has a concave receiving surface portion (60) that is recessed toward the inside of the carrier body (1) and into which the buffer protrusion (5) of the carrier (100) traveling behind fits.

Description

[Technical field]

[0001] The present disclosure relates to a conveying device including a plurality of carriers for conveying an object. [Background technology]

[0002] Conventionally, a conveying device equipped with a plurality of carriers that travel on the same rail to convey an object has been known. The plurality of carriers are independently driven and controlled by a linear motor. In the conveying device, since the plurality of carriers travel independently on the rail, it is necessary to mitigate the impact force when adjacent carriers collide with each other. For example, Patent Document 1 discloses a carrier braking mechanism that uses a braking device to brake a runaway carrier when the carrier traveling along the rail runs out of control. This carrier braking mechanism includes a stopper member made of a buffer material provided at the end of the rail, and a clamping mechanism that clamps a plate member attached to the underside of the carrier. The plate member of the traveling carrier is clamped by the clamping mechanism, and the carrier is decelerated by the friction and collided with the stopper member, thereby mitigating the impact force on the carrier. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 61-247563 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology disclosed in Patent Document 1 is a configuration for stopping a runaway carrier at the end of a rail, and is not a configuration for mitigating the impact force when adjacent carriers collide with each other.

[0005] The present disclosure has been made in consideration of the above, and has an object to provide a conveying device that can reduce the impact force when adjacent carriers collide with each other. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the conveying device according to the present disclosure includes a plurality of carriers that are independently driven and controlled by linear motors and travel on the same rail to convey an object. The carriers include a carrier body that holds the object and travels along the rail, and a buffer mechanism that is attached to the carrier body and buffers the impact force when adjacent carriers collide with each other. The buffer mechanism includes a buffer protrusion that protrudes toward the carrier located in front, and a buffer receiving portion that receives the buffer protrusion of the carrier traveling behind. The buffer receiving portion has a concave receiving surface that is recessed toward the inside of the carrier body and into which the buffer protrusion of the carrier traveling behind fits. Effect of the Invention

[0007] The transport device according to the present disclosure has the advantage that when adjacent carriers collide with each other, the impact force can be reduced. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a top view showing a state in which the conveying device according to the first embodiment is made to travel along a linear rail; [Diagram 2] FIG. 1 is a perspective view showing a carrier constituting a transport device according to a first embodiment; [Diagram 3] FIG. 1 is a top view showing a schematic diagram of a state in which the conveying device according to the first embodiment is made to travel along a curved rail; [Figure 4] FIG. 1 is an explanatory diagram showing a dynamic model of a carrier collision in the transport device according to the first embodiment; [Diagram 5] A graph showing the time history waveform of the impact force in the dynamic model shown in Figure 4. [Figure 6] FIG. 1 is an explanatory diagram showing force vectors of an impact force, an inertial force, and a bearing reaction force when carriers collide with each other in the transport device according to the first embodiment; [Figure 7]FIG. 1 is a top view showing a modified example of the conveying device according to the first embodiment, in which the conveying device runs on a left-curved rail. [Figure 8] FIG. 1 is a top view showing a modified example of the conveying device according to the first embodiment, in which the conveying device runs on a right-curved rail. [Figure 9] FIG. 11 is a perspective view showing a carrier constituting a transport device according to a second embodiment; [Figure 10] FIG. 11 is an explanatory diagram showing a schematic diagram of a carrier constituting a transport device according to a second embodiment, illustrating the force vectors of the impact force and the inertial force when the carriers collide with each other; [Figure 11] FIG. 13 is a top view showing a state in which the conveying device according to the third embodiment is made to travel along a linear rail. [Figure 12] FIG. 11 is a side view showing a schematic diagram of a state in which the conveying device according to the third embodiment is made to travel along a linear rail. [Figure 13] FIG. 11 is a side view showing a pressing force and a contact reaction force vector of a braking mechanism of a conveying device according to a third embodiment. [Figure 14] FIG. 13 is a top view showing a state in which the conveying device according to the third embodiment is made to travel along a curved rail. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a conveying device according to an embodiment of the present disclosure will be described in detail with reference to the drawings.

[0010] Embodiment 1 Fig. 1 is a top view showing a state in which the conveying device according to the first embodiment is made to travel along a linear rail. Note that in Fig. 1, a conveyed object 300 placed on the upper surface of the carrier 100 is omitted. Fig. 2 is a perspective view showing a carrier 100 constituting the conveying device 200 according to the first embodiment. In the drawing, the Z axis is the vertical direction, the X axis is the direction along the rail 201, and the Y axis is the direction perpendicular to the Z axis and the X axis.

[0011] As shown in FIG. 1 and FIG. 2, the conveying device 200 includes a plurality of carriers 100 that are driven by a linear motor and travel on the same rail 201 to convey a conveyed object 300. The plurality of carriers 100 are not connected to each other, and travel independently on the rail 201 by the drive control of the linear motor, and stop at a target position. The linear motor is composed of a mover provided on the carrier 100 and a stator provided on the rail 201, which is the stationary side. The carriers 100 are independently driven and controlled by controlling the current flowing through the coil of the stator. The conveying device 200 is not limited to the configuration in which three carriers 100 are arranged on the rail 201 as shown in FIG. 1, but may be configured to have two carriers 100 arranged on the rail 201, or may be configured to have four or more carriers 100 arranged on the rail 201.

[0012] The carrier 100 includes a carrier body 1, a roller 2, a mover 3, and a buffer mechanism 4. The carrier body 1 holds the transported object 300 and travels along a rail 201. The carrier body 1 has a first surface 10 constituting the upper surface, a second surface 11 constituting the lower surface, and a third surface 12 connecting the first surface 10 and the second surface 11 and constituting a side surface. The carrier body 1 is concave with the first surface 10, the second surface 11, and the third surface 12. The carrier body 1 travels along the rail 201 by disposing the rail 201 inside the concave. The transported object 300 is placed on the upper surface of the first surface 10 of the carrier body 1 via the buffer mechanism 4. The shape of the carrier body 1 is not limited to the concave shape shown in the figure, and may be, for example, an H shape or a cylindrical shape. In short, the carrier body 1 may have any other shape as long as it is configured to hold the transported object 300 and run along the rail 201.

[0013] As shown in FIG. 2, the rollers 2 are attached to the first surface 10 and the second surface 11 of the carrier body 1, for example. The rollers 2 are attached to the carrier body 1 via rolling bearings (not shown). As shown in FIG. 1, the rollers 2 attached to the first surface 10 are provided, for example, in four on a concave inner surface so as to sandwich the rail 201 from both sides. The rollers 2 attached to the second surface 11 are provided, for example, in two on a concave outer surface so as to roll along the rail 201. The positions and number of the rollers 2 are not limited to the configuration shown in the figure, and may be appropriately changed and provided according to the shape of the carrier body 1.

[0014] The mover 3 and a stator (not shown) constitute a linear motor. The mover 3 has a mover core 30 made of a magnetic material and a plurality of permanent magnets (not shown) arranged so that the polarities are staggered. The permanent magnets are arranged on the back surface of the mover core 30. A stator (not shown) is arranged on the rail 201. The stator has a stator core made of a magnetic material arranged so as to face the mover 3, and a coil attached to the stator core. The carrier 100 is driven by generating a propulsive force by controlling the current flowing through the stator coil. In addition, a position sensor is attached to the carrier 100, and the running speed of the carrier 100 is controlled by controlling the current to the stator coil by feedback of the position of the carrier 100, and the positioning to the target position is controlled.

[0015] 1, the buffer mechanism 4 is attached to the carrier body 1, and serves to absorb the impact force when adjacent carriers 100 collide with each other. The buffer mechanism 4 includes a buffer protrusion 5 that protrudes toward the carrier 100 located in front, and a buffer receiving portion 6 that receives the buffer protrusion 5 of the carrier 100 traveling behind. The buffer protrusion 5 is made of an elastic member such as anti-vibration rubber, and comes into contact with the buffer receiving portion 6 of the carrier 100 located in front.

[0016] As shown in FIG. 2, the cushioning receiving part 6 is made of an elastic member such as anti-vibration rubber, and is attached to the upper surface of the first surface part 10 of the carrier body part 1. The transported object 300 is held on the first surface part 10 of the carrier body part 1 via the cushioning receiving part 6 of the cushioning mechanism 4. That is, the cushioning receiving part 6 is installed on the upper surface of the carrier body part 1 close to the overall center of gravity position including the transported object 300 and the carrier 100. The cushioning receiving part 6 is formed as a rectangular cylinder as an example, and has a concave receiving surface part 60 in which one of the four sides is recessed toward the inside of the carrier body part 1 and into which the cushioning protrusion part 5 of the carrier 100 traveling behind enters. The conveying device 200 has a length of the cushioning protrusion part 5 longer than the depth of the recess of the receiving surface part 60. As a result, the conveying device 200 can receive the cushioning protrusion part 5 with the cushioning receiving part 6 before the carrier body parts 1 of the front and rear carriers 100 collide with each other. Furthermore, in the conveying device 200 of embodiment 1, the buffer protrusion 5 is configured to fit into the receiving surface 60 of the buffer receiving portion 6, so that there is no interference between the buffer protrusion 5 and the buffer receiving portion 6, and the carrier 100 located in front and the carrier 100 traveling behind can be brought close to each other. This widens the positioning range of the carrier 100, and enables the transported object 300 to be transported to the target position.

[0017] FIG. 3 is a top view showing a state where the conveying device according to the first embodiment is made to run along a curved rail. As shown in FIG. 3, when the conveying device 200 makes a plurality of carriers 100 run along a curved rail 202, the yawing (rotation around the Z axis) angles of the carriers 100 located at the front and rear are different. Therefore, the cushioning protrusion 5 of the rear carrier 100 does not abut against the groove bottom of the receiving surface 60 of the cushioning receiving part 6 of the carrier 100 located at the front, but the abutment position moves and abuts against the side wall surface connecting the concave opening end to the groove bottom. Therefore, the side wall surface of the receiving surface 60 of the cushioning receiving part 6 is formed in a curved shape corresponding to the curve of the curved rail 202. As a result, even when the conveying device 200 is made to run along the curved rail 202, the tip of the cushioning protrusion 5 can be made to abut against the curved side wall surface of the receiving surface 60, so that the cushioning protrusion 5 can abut against the cushioning receiving part 6 before the adjacent carrier main body parts 1 collide, thereby mitigating the impact force.

[0018] Fig. 4 is an explanatory diagram showing a dynamic model of carrier collision in the transport device according to the first embodiment. In Fig. 4, the components are represented as follows. The wall surface on the left side of the page is the front carrier 100A, the square box on the right side of the page is the rear carrier 100B, and the schematic diagram of the spring is the buffer protrusion 5. In addition, the schematic diagram of the roller supporting the rear carrier 100B from below is the roller 2, and the floor surface is the rail 201.

[0019] 5 is a graph showing the time history waveform of the impact force in the dynamic model shown in FIG. 4. The vertical axis represents the impact force f c 5. The horizontal axis represents time t. From time 0 to t1 shown in FIG. 5, the buffer protrusion 5 of the rear carrier 100B does not contact the front carrier 100A. Therefore, the impact force applied from the buffer protrusion 5 to the carriers 100A and 100B is zero. Then, from t1, which is the moment when the buffer protrusion 5 of the rear carrier 100B contacts the front carrier 100A, the impact force increases and reaches a maximum value, then decreases and becomes zero again at time t2. The maximum value of the impact force is halfway between t1 and t2.

[0020] If the cushioning protrusion 5 is within the range of elastic deformation, the spring force generates a repulsive force proportional to the amount of contraction of the cushion. Therefore, if friction and damping are ignored, the waveform of the impact force will be a half-sine wave. That is, when the rear carrier 100B travels at a constant speed v and collides with the stationary front carrier 100A, a repulsive force with a half-sine wave shape as shown in FIG. 5 is generated. At this time, if the travel speed of the rear carrier 100B is v and the mass is m, the momentum is mv, and the impact force f c Since it is equal to the time integral from time t1 to t2, it can be expressed as equation (1).

[0021]

number

[0022] Impact force f c Since f is a half sine wave, it can be expressed as equation (2). Here, n is equation (3).

[0023]

number

[0024]

number

[0025] Substituting equation (3) into equation (2) and assuming the acceleration of the rear carrier 100B as α, we get f c =mα, and by substituting this into equation (1) and calculating the integral, we obtain equation (4).

[0026]

number

[0027] Here, α max is the maximum value of acceleration α. ​​By eliminating m from both sides of equation (4) and rearranging, we obtain equation (5).

[0028]

number

[0029] Here, ω n is the natural angular frequency, and ω n =2πf n This is expressed as:

[0030] The maximum impact force applied to carrier 100 is α max The natural angular frequency ω n The value of acceleration α and impact force f c For example, the vibration-proof rubber of the buffer protrusion 5 is the same as that of the vibration-proof rubber stopper (model: RE4000A5) manufactured by NOK, and the protrusion height is 50 mm, the cushion bottom width is 29 mm, and the cushion tip width is 13 mm. When the mass m of the carrier 100B is 1 kg, the natural frequency f n is 19.2Hz. In addition, the maximum value of the impact acceleration α when the carrier 100B collides with the vehicle at a speed v of 1 m / sec is max The impact force f is 6.2G. c So, 6.2kgf = 6.2 x 9.8 = 60.8N.

[0031] Fig. 6 is an explanatory diagram showing the force vectors of the impact force, inertia force, and bearing reaction force when carriers collide with each other in the conveying device according to the first embodiment. Fig. 6 shows the force vectors of the impact force a, the inertia force b, and the bearing reaction force c when the carrier 100 located in the front receives impact acceleration from the carrier 100 traveling from behind. The symbol of a circle with black and white crosses shown in Fig. 6 indicates the center of gravity of the carrier 100 and the conveyed object 300 combined.

[0032] The center of gravity of the entire load 300 and carrier 100 is at the base of the arrow representing the inertial force b, and is shifted upward on the paper surface of FIG. 6 due to the mass of the load 300 (not shown). The impact force a and the inertial force b are equal in magnitude and in opposite directions, and balance is maintained in the X direction along the rail 201. The impact force a and the inertial force b are not on the same line, and a moment force with the distance between the impact force a and the inertial force b as the moment arm acts on the carrier 100, and a bearing reaction force c is generated to balance this moment force. The bearing reaction force c acts perpendicular to the track of the rail 201 because the roller 2 is supported by the carrier 100 with a rolling bearing (not shown) and the rotational sliding resistance is negligibly small. If the bearing distance that generates bearing reaction force c is doubled relative to the distance between impact force a and inertia force b, bearing reaction force c will be 1 / 2 of the impact load of 6.2 kgf, or 3.1 kgf = 30.4 N. If bearing reaction force c can be reduced in this way, even if a ball bearing with a small diameter of about 10 mm and a small static load rating of 218 N is used as the rolling bearing, bearing reaction force c will be below the static load rating, and the bearing life will be long. In other words, the moment force of impact force a and inertia force b can be reduced, and the impact load on the rolling bearing that constitutes carrier 100 can be reduced, so carrier 100 can be made smaller and its mechanical life can be extended.

[0033] Fig. 7 is a top view of a modified example of the conveyance device according to the first embodiment, showing a case where the device runs on a rail that curves to the left. Fig. 8 is a top view of a modified example of the conveyance device according to the first embodiment, showing a case where the device runs on a rail that curves to the right.

[0034] As shown in Fig. 7 and Fig. 8, the conveying device 200 configures the buffer receiving section 6 so that the carrier 100 can travel along the left curve shown in Fig. 7 and the right curve shown in Fig. 8. The receiving surface section 60 of the buffer receiving section 6 has a pair of side wall surfaces extending from the concave opening end toward the bottom of the groove. The receiving surface section 60 is configured such that one side wall surface is formed in a curved shape corresponding to the curve of the rail 202 of the left curve shown in Fig. 7, and the other side wall surface is formed in a curved shape corresponding to the curve of the rail 203 of the right curve shown in Fig. 8. The carrier 100 moves along the rails 202, 203 so that the buffer protrusions 5 are positioned outside the radius of curvature of the curves of the rails 202, 203. As a result, even when the conveying device 200 is made to run along an S-shaped track consisting of a left-curving rail 202 and a right-curving rail 203, the tip of the buffer protrusion 5 can be abutted against the side wall surface of the receiving surface 60, so that the buffer protrusion 5 can abut against the buffer receiving portion 6 before the carriers 100 collide with each other, thereby mitigating the impact.

[0035] As described above, the conveying device 200 according to the first embodiment includes a plurality of carriers 100 that are independently driven and controlled by linear motors and travel on the same rail to convey the conveyed object 300. The carrier 100 includes a carrier body 1 that holds the conveyed object 300 and travels along the rail 201, and a buffer mechanism 4 that is attached to the carrier body 1 and absorbs the impact force when adjacent carriers 100 collide with each other. The buffer mechanism 4 includes a buffer protrusion 5 that protrudes toward the carrier 100 located in front, and a buffer receiving portion 6 that receives the buffer protrusion 5 of the carrier 100 traveling behind. The buffer receiving portion 6 has a concave receiving surface portion 60 that is recessed toward the inside of the carrier body 1 and into which the buffer protrusion 5 of the carrier 100 traveling behind fits.

[0036] Therefore, the conveying device 200 according to the first embodiment includes a buffer mechanism 4 for buffering collisions between adjacent carriers 100, and is configured so that the buffer protrusions 5 of the carrier 100 traveling behind are received by the buffer receiving parts 6 of the carrier 100 located in front, so that when adjacent carriers collide with each other, the impact force can be buffered. Also, the buffer receiving parts 6 are recessed toward the inside of the carrier body 1, and have a concave receiving surface part 60 into which the buffer protrusions 5 of the carrier 100 traveling behind are inserted. Therefore, the buffer protrusions 5 and the buffer receiving parts 6 do not interfere with each other, and the carrier 100 traveling in front and the carrier 100 traveling behind can be brought close to each other, so that the positioning range of the carrier 100 is widened, and the conveyed object 300 can be conveyed to the target position.

[0037] Embodiment 2 Next, a conveying device 200 according to a second embodiment will be described. Fig. 9 is a perspective view showing a carrier constituting the conveying device according to the second embodiment. Fig. 10 is a schematic diagram showing the carrier constituting the conveying device according to the second embodiment, and is an explanatory diagram showing the force vectors of the impact force and the inertial force when the carriers collide with each other. The symbol of a circle with black and white crosses shown in Fig. 10 indicates the center of gravity of the carrier 100 and the conveyed object 300 combined.

[0038] As shown in Fig. 9, the transported object 300 is disposed on the outer surface of the third surface portion 12 of the carrier body 1. That is, the transported object 300 is disposed in a position facing the mover core 30. As shown in Fig. 10, when the transported object 300 is disposed on the outer surface of the third surface portion 12 of the carrier body 1, the position of the center of gravity of the carrier 100 and the transported object 300 is approximately at the center of the carrier body 1, near the mover core 30 and the transported object 300. In this case, the buffer receiving parts 6 are installed at the upper and lower parts of the carrier body 1 at equal intervals from the position of the center of gravity of the carrier 100 and the transported object 300, with the position of the center of gravity of the carrier 100 and the transported object 300 as the center.

[0039] In the conveying device 200 according to the second embodiment, when the rear carrier 100 collides with the front carrier 100, an impact force a and an inertial force b are generated as shown in FIG. 10. The inertial force b is generated so as to balance with the impact force a from the buffer protrusion 5. The impact force a from the buffer protrusion 5 is generated at the two buffer receiving parts 6 arranged above and below the center of gravity. At this time, the moment around the Y axis is balanced by the impact force a and the inertial force b. As a result, the conveying device 200 can reduce the load acting on the rollers 2 supporting the carrier body 1 and the rolling bearings (not shown), and therefore the carrier 100 can be made smaller by using a small diameter rolling bearing, and the mechanical life of the carrier 100 can be extended.

[0040] Embodiment 3 Next, a conveying device 200A according to a third embodiment will be described with reference to Fig. 11 to Fig. 14. Fig. 11 is a top view showing a state in which the conveying device according to the third embodiment runs along a linear rail. Fig. 12 is a side view showing a state in which the conveying device according to the third embodiment runs along a linear rail.

[0041] 11 and 12, in addition to the configuration of the first or second embodiment, the transport device 200A according to the third embodiment includes a braking mechanism 7 that brakes the carrier 100 by sliding friction with the rail 201. The other configurations are the same as those of the first or second embodiment, so detailed explanations are omitted. For convenience of explanation, in Figs. 11 and 12, the carrier 100 located at the front is indicated as carrier 100A, and the carrier 100 traveling behind is indicated as carrier 100B.

[0042] The brake mechanism 7 has a brake link 70, a pin 71, and a slider 72. As shown in FIG. 12, the brake link 70 is formed in a substantially L-shape with a first flat portion 70a extending along the vertical direction and a second flat portion 70b extending along the traveling direction of the rail 201 when the carriers 100A, 100B are viewed from the side. The brake link 70 is supported so as to be rotatable in the vertical direction around a pin 71 provided at the vertical center of the first flat portion 70a. The pin 71 is fixed to the carrier body 1, for example. The slider 72 is attached to the second flat portion 70b of the brake link 70. The slider 72 moves in conjunction with the rotation of the brake link 70 and comes into contact with a rail base 201a, which is a part of the rail 201, to generate sliding friction. The slider 72 is not limited to a configuration in which it contacts the rail base 201a, but may be configured to contact other portions of the rail 201.

[0043] 12, in the braking mechanism 7 configured as described above, when the rear carrier 100B approaches the front carrier 100A and the buffer protrusion 5 enters the receiving surface 60 of the buffer receiving part 6, the tip of the buffer protrusion 5 abuts against the second flat surface 70b of the brake link 70, causing the brake link 70 to rotate downward as shown by the arrow T. When the brake link 70 rotates, the slider 72 attached to the brake link 70 abuts against the rail base 201a to generate sliding friction, thereby braking the carriers 100A and 100B.

[0044] In this way, the conveying device 200A according to the third embodiment has the braking mechanism 7, and thus the collision speed of the carrier 100 can be reduced, and thus the impact force can be mitigated. Furthermore, the impact force can be mitigated, and thus the buffer mechanism 4 can be made smaller. Furthermore, the load acting on the rollers 2 supporting the carrier body 1 and the rolling bearings (not shown) can be reduced, and thus the mechanical life of the carrier 100 can be extended. Note that the braking link 70 is not limited to a configuration in which it is rotatably supported by the pin 71 as shown in the figure, and may be rotatably supported by a leaf spring structure or other structure.

[0045] 13 is a side view showing the pressing force and the contact reaction force vector of the braking mechanism of the conveying device according to the third embodiment. As shown in FIG. 13, the contact reaction force of the buffer protrusion 5 against the braking link 70 is expressed as a contact reaction force vector F r , contact reaction force vector F r The angle between the vertical direction (Z direction) and the rear carrier 100B is the pressing force vector F x The pressing force vector F x and the contact reaction force vector F r The relationship is expressed by equation (6).

[0046]

number

[0047] When the coefficient of friction between the buffer protrusion 5 and the receiving surface 60 of the buffer receiving part 6 is μ and equation (7) is satisfied, the wedge effect causes the buffer protrusion 5 to be fixed to the receiving surface 60 of the buffer receiving part 6 without slipping.

[0048]

number

[0049] That is, the pushing force vector F x is amplified by 1 / sinθ to the contact reaction vector F r And this contact reaction force vector F r is the inclined surface pressing force, and a sliding friction reaction force is generated by multiplying it by the friction coefficient μ. Pressing force vector F x The larger the frictional reaction force, the greater the sliding friction reaction force, and so-called automatic tightening occurs, causing the buffer protrusion 5 to adhere to the receiving surface 60 of the buffer receiving part 6. This adherence state can be easily released by controlling the thrust of the front and rear carriers 100A, 100B to generate thrust in the direction in which the carriers 100A, 100B move away from each other. Then, by smoothly starting the carriers 100A, 100B from the state in which the automatic tightening has been released, it becomes possible to transition to the normal transport mode.

[0050] On the other hand, when the buffer protrusion 5 is fixed to the receiving surface 60 of the buffer receiving portion 6 and the rear carrier 100B is further pressed against the front carrier 100A, the pressing force is accumulated as elastic deformation of the buffer protrusion 5 and the buffer receiving portion 6, and even if the drive control of the carriers 100A, 100B is turned off, the restoring force due to the elastic deformation and the frictional force are balanced, so that the carriers 100A, 100B are held stationary.

[0051] Each carrier 100A, 100B is provided with a mover core 30, and the thrust is controlled independently of the other carriers 100A, 100B by controlling the current of the coil of the stator (not shown). Therefore, the pressing force for holding the carriers 100A, 100B stationary can be adjusted, and by setting the friction force to be larger than the weight of the carriers 100A, 100B, it is possible to prevent the carriers from shifting position due to their own weight. In other words, even if the rail 201 is arranged in a vertical plane and the weight of the carriers 100A, 100B includes a vertical component, the carriers 100A, 100B can be held stationary by turning off the drive control of the carriers 100A, 100B.

[0052] Fig. 14 is a top view showing a state where the conveyance device according to the third embodiment is made to travel along a curved rail. As shown in Fig. 14, the conveyance device 200A according to the third embodiment can achieve the above-mentioned effects even when made to travel along a curved rail 202, similarly to the case where the conveyance device 200A is made to travel along a straight rail 201.

[0053] The configurations shown in the above embodiments are merely examples, and may be combined with other known techniques or may be combined with other embodiments. In addition, it is also possible to omit or modify a part of the configuration without departing from the scope of the present invention. [Explanation of symbols]

[0054] 1 carrier body, 2 roller, 3 mover, 4 buffer mechanism, 5 buffer protrusion, 6 buffer receiving portion, 7 braking mechanism, 10 first surface, 11 second surface, 12 third surface, 30 mover core, 60 receiving surface, 70 braking link, 70a first flat portion, 70b second flat portion, 71 pin, 72 slider, 100, 100A, 100B carrier, 200, 200A conveying device, 201, 202, 203 rail, 201a rail base, 300 conveyed object.

Claims

1. A conveying device having a plurality of carriers that are independently driven and controlled by linear motors and travel on the same rail to convey objects, The carrier is a carrier body portion that holds the transported object and travels along the rail; a buffer mechanism attached to the carrier body portion for buffering an impact force when adjacent carriers collide with each other, The buffer mechanism includes: a buffer protrusion protruding toward the carrier located in the front; a shock-absorbing receiving portion that receives the shock-absorbing protrusion of the carrier traveling rearward; The cushioning receiving portion is recessed toward the inside of the carrier body portion and has a concave receiving surface portion into which the cushioning protrusion portion of the carrier traveling rearward is inserted. A conveying device characterized by the above.

2. The receiving surface portion has a side wall surface that is curved from an opening end of the concave shape toward a bottom of the groove.

2. The conveying device according to claim 1.

3. The transported object is held at an upper portion of the carrier body, The cushioning receiving portion is installed on the upper surface of the carrier body portion close to the center of gravity of the entire structure including the transported object and the carrier.

2. The conveying device according to claim 1.

4. The transported object is held at an upper portion of the carrier body, The cushioning receiving portion is installed on the upper surface of the carrier body portion close to the center of gravity of the entire structure including the transported object and the carrier.

3. The conveying device according to claim 2.

5. The transported object is held by a vertical side surface of the carrier body, The cushioning receiving parts are installed at the upper and lower parts of the carrier body part, centered on the overall center of gravity including the transported object and the carrier.

2. The conveying device according to claim 1.

6. The transported object is held by a vertical side surface of the carrier body, The cushioning receiving parts are installed at the upper and lower parts of the carrier body part, centered on the overall center of gravity including the transported object and the carrier.

3. The conveying device according to claim 2.

7. The carrier further includes a braking mechanism that brakes the carrier by sliding friction with the rail.

7. The conveying device according to claim 1, wherein the conveying device is a conveying device.

8. The braking mechanism includes a braking link that rotates when the buffer protrusion abuts against the braking link, and a slider that moves in conjunction with the rotation of the braking link and comes into contact with a part of the rail to generate sliding friction.

8. The transport device according to claim 7.

9. When an angle between a contact reaction vector of the buffer protrusion with respect to the brake link and a vertical direction is defined as θ, and a friction coefficient between the buffer protrusion and the buffer receiving portion is defined as μ, the θ is set so that μ>tan θ.

9. The conveying device according to claim 8.