JP2000255744A - Linear carrying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear carrying device allowing elongation of a service life of a linear motor, allowing setting of a reciprocation stroke of a trough over an upper limit displacement amount of a moving body of the linear motor, and allowing sufficient reduction of generation of vibration accompanying the drive without increasing weight of the device. SOLUTION: This linear carrying device has a trough 25 for placing material M; a linear motor 26; a guide body 27 for guiding the trough 25 back and forth in a carrying direction X; a power transmission mechanism 28 connecting a moving body 38 of the linear motor 26 with the trough 25 to reciprocate the trough 25 along the guide body 27 in the carrying direction X in the opposite direction of motion direction of the moving body 38 by the motion of the moving body 38; and a controller 29 for controlling the linear motor 26 to carry the material M by the reciprocation of the trough 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear transport device for transporting articles by using a linear motor as a drive source.

[0002]

2. Description of the Related Art A leaf spring type transfer device is known as a transfer device for transferring an article by reciprocating a trough on which the article is placed. In this transfer device, a trough is supported on a base via a leaf spring having an inclined posture, and the trough is intermittently attracted from below by an electromagnet, and is attracted by the electromagnet and attracted by a restoring force of the leaf spring. By repeating the cancellation
The trough is flipped up in a direction upward and forward with respect to the transport direction to transport the articles on the trough.

[0003] However, in the leaf-spring type transport apparatus having the above-described configuration, vibration is applied to the base supporting the transport apparatus as the trough is repeatedly jumped up. Even if the transport device having such a configuration is used as a feeder for supplying articles to a weighing unit in, for example, a combination weighing and counting device, accurate weighing cannot be performed.

As an alternative to such a leaf spring-type transfer device, the applicant of the present application has previously described a driving device for reciprocating a trough, a coil fixedly supported on a housing, and a linearly movable member mounted on the housing. There has been proposed a linear transport device having a configuration in which a linear stepping motor having a magnet fixed to a shaft supported by a shaft is used, and a trough is supported on the shaft via a bracket.

In the case of this linear transport apparatus, since a linear stepping motor is used as a driving device, switching of the trough moving speed, reciprocating stroke, and the like can be selected according to the type and transport amount of the article to be transported. It is possible to properly convey a desired amount of articles according to the type and the amount of conveyance.

However, in the case of the linear transfer device having the above-described configuration, there are the following problems. (1) Since the weight of the trough and the bracket all hang on the shaft of the linear stepping motor, the life of the bearing that slides the shaft is shortened. (2) Since the displacement amount of the shaft and the displacement amount of the trough are the same, the reciprocating stroke of the trough cannot be set to a value exceeding the upper limit displacement amount of the shaft. (3) Compared with the conventional leaf spring type transport device, the vibration applied to the base supporting the transport device due to the reciprocation of the trough is reduced to some extent, but cannot be reduced sufficiently.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is possible to extend the life of a linear motor which is a driving machine, and to reciprocate a trough beyond an upper limit displacement of a moving body of the linear motor. It is an object of the present invention to provide a linear transfer device capable of setting a stroke and sufficiently reducing generation of vibrations due to driving without increasing the weight of the device.

[0008]

According to a first aspect of the present invention, there is provided a linear transport apparatus comprising: a trough on which articles are placed; a linear motor; A guide that guides forward and backward, a moving body of the linear motor and the trough are connected, and the trough moves back and forth in the transport direction along the guide in a direction opposite to a moving direction of the moving body. Power transmission mechanism to move,
A controller that controls the linear motor to convey articles by reciprocating the trough.

According to the linear transfer device, the power transmission mechanism operates by the linear movement of the moving body of the linear motor,
The trough reciprocates back and forth in the transport direction by the guide, thereby transporting the articles on the trough. Since the trough load is not applied to the moving body of the linear motor, the life of the linear motor can be extended. In addition, since the trough reciprocates in the direction opposite to the moving direction of the moving body of the linear motor, the inertial force of the trough can be canceled, and the vibration applied to the base supporting the transfer device due to the reciprocation of the trough can be sufficiently reduced. . Further, since the linear movement of the moving body of the linear motor is transmitted to the trough via the power transmission mechanism, the reciprocating stroke of the trough can be set to exceed the upper limit displacement of the moving body of the linear motor.

[0010] Further, the linear transport device according to a second aspect of the present invention is the linear transport device according to the first aspect, further comprising control condition setting means for setting a control condition according to the type of article in the controller. is there.

According to the linear transport device, when the type of article to be transported changes and the operator sets the corresponding control condition in the controller by the control condition setting means, the operation mode corresponding to the control condition is set. As described above, since the controller controls the linear motor, the operation mode of the linear motor can be freely switched and controlled in accordance with the type of the article to be transported and the transport amount.

According to a third aspect of the present invention, in the linear transfer device, the first link in which the power transmission mechanism is rotatably connected at one end to the moving body. A member, a second link member having one end rotatably connected to the trough, one end being the other end of the first link member, and the other end being the other end of the second link member. A third link member is rotatably connected to each other, and is rotatably supported about a support shaft at an intermediate portion.

According to the linear transfer device, the power transmission mechanism can be easily configured, and the support shaft position of the third link member is set at a position close to the first link member.
The reciprocating stroke of the trough can be easily and reliably set to exceed the upper limit displacement of the moving body of the linear motor.

According to a fourth aspect of the present invention, in the linear transport device according to any one of the first to third aspects, a weight for canceling an inertial force of the trough is fixed to the movable body.

According to the linear transfer device, since the weight of the weight is added to the weight of the moving body of the linear motor and acts to cancel the inertia force of the trough, the transfer device is supported as the trough reciprocates. Vibration applied to the base can be reduced more reliably.

According to a fifth aspect of the present invention, there is provided a linear transport device according to any one of the first to fourth aspects, wherein the linear motor comprises: a coil fixed to a housing;
The linear stepping motor includes a shaft which is supported by the housing so as to be linearly movable and forms the moving body, and a magnet fixed to the shaft.

According to the linear transfer device, since the linear motor is compactly configured, when used as a feeder in a combination weighing device in which a plurality of feeders are radially arranged toward the weighing section, an installation space is significantly reduced. It can be arranged compactly without need.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cut-away schematic front view showing a combination weighing device provided with a linear transport device according to an embodiment of the present invention. In FIG.
The articles M, such as snacks, which are objects to be weighed and conveyed by the conveyor 1 are supplied via a charging chute 2 onto a single flat cone-shaped dispersion feeder 3. The dispersion feeder 3 is vibrated by being vibrated up and down by the driving of the vibrator 4, and disperses the articles M in all directions. A plurality of transfer feeders 7 each composed of a linear transport device are radially arranged around the lower part of the dispersion feeder 3, and a plurality of pool hoppers 9 correspond to the respective transfer feeders 7 below the tip of each transfer feeder 7. They are arranged in a circle. Further, a plurality of weighing hoppers 1 are provided below the pool hopper 9.
Numerals 0 are circularly arranged so as to correspond to the respective pool hoppers 9 individually.

Each of the transfer feeders 7 includes a dispersion feeder 3.
Is supplied to the corresponding pool hopper 9 by horizontal reciprocating motion, the pool hopper 9 temporarily pools the input product M, and then discharges the product M by opening the gate 13. And supply it to the weighing hopper 10.

The weighing hopper 10 includes the weighing hopper 1
It is supported by a case 23 to be described later via a weighing unit 11 such as a load cell that weighs the weight of the article M in 0. Thus, the pool hopper 9, the weighing hopper 10, and the weighing means 11 form a weighing unit. Below the weighing hopper 10, a collecting and discharging chute 17 that collects the articles M discharged from the weighing hopper 10 at the lower center is disposed. The articles M discharged from the weighing hopper 10 are collected by the collecting and discharging chute section 17. Then, it is supplied to a packaging machine 19 through a distribution chute 18 and packed.

A main body frame 21 is mounted on a support frame 20 supported on a floor (not shown), and the case 23 is supported on the main body frame 21 via a plurality of support legs 22. A charging chute 2, a dispersion chute 3, a transfer feeder 7, and a pool hopper 9 are arranged on the upper portion of the case 23, and a weighing hopper 10 is arranged on the outer periphery of the case 23, and a weighing means 11 is arranged on the inner side. ing. In the case 23, a control unit 24 of the pool hopper 9 and the weighing hopper 10, a drive motor, and the like are housed.

The control unit 24 in the case 23 performs a combination operation of the weighing values of the articles M of the plurality of weighing hoppers 10, selects the articles M in the weighing hopper 10 having a combined weight within an allowable range, and selects them. The gate 14 of the weighing hopper 10 is opened to supply the articles M to the packaging machine 19.

FIGS. 2A and 2B are a block diagram showing a configuration of a control system of the transfer feeder 7, and a rear sectional view of the transfer feeder 7. As shown in FIGS. The transfer feeder 7 composed of a linear transport device includes a trough 25 on which articles M to be transported are placed, a linear motor 26 as a driving source, and a guide for guiding the trough 25 back and forth along a horizontal transport direction X. Body 27, a power transmission mechanism 28 for reciprocating the trough 25 in the transport direction X along the guide body 27 by driving the linear motor 26, and a reciprocating motion of the trough 25 by controlling the linear motor 26. A controller 29 for transporting the article M; Control conditions according to the type of the article M and the like are set in the controller 29 by an operator using the control condition setting means 30.

The linear motor 26 comprises a moving body 38 having a cylindrical housing 35, a coil 36 fixedly supported on the inner wall of the housing 35, and a magnet 37 capable of linearly moving in the housing 35 in the axial direction. And a linear stepping motor. The moving body 38 includes a shaft 40 supported by front and rear linear bearings 39, penetrating the housing 35 so as to be able to linearly move in the axial direction thereof, and the magnet 37 fixed to the shaft 40. The linear motor 26 is installed on the base 41 with the axis of the shaft 40 oriented in the transport direction X. A weight 44 for canceling the inertial force of the trough 25 is fixed to the shaft 40.

As described above, since a linear stepping motor having a compact configuration is used as a driving device of the transfer feeder 7 which is a linear transfer device, a large number of transfer feeders 7 are radially arranged as in the combination weighing device shown in FIG. When installing in a small space, it does not require much installation space,
Can be arranged compactly.

The guide 27 is provided on the linear motor 26.
, Which is installed on the base 41 so as to extend along the transport direction X, and the upper surface thereof is
The transport surface S has a plurality of free rollers 42 arranged thereon. On both front and rear sides of the lower surface of the trough 25, guide rollers 43 having a rotation axis in a vertical posture are provided on the guide body 27.
Are installed so as to be rotatably in contact with both side surfaces.
This allows the trough 25 to move smoothly back and forth in the transport direction X without rattling in the width direction of the guide 27.

The power transmission mechanism 28 includes a support leg 51 erected on the base 41 and three link members 61 to 63. That is, one end of the first link member 61 is rotatably connected to the side surface of the connecting body 54 fixed to the shaft 40 of the linear motor 26 via the support shaft 55. One end of the second link member 62 is rotatably connected to a side surface of a support member 56 projecting downward from one side of the trough 25 via a support shaft 57. Third
One end of the link member 63 is connected to the first
The other end of the third link member 63 is rotatably connected to the other end of the second link member 62 via a support shaft 65. ing. Further, the third link member 63 is rotatably supported around a support shaft 52 by a support leg 51 erected on the base 41 at an intermediate portion thereof. Also, the third link member 6
The distance b from the intermediate portion to the connecting portion to the second link member 62 is larger than the distance a from the intermediate portion supported around the support shaft 52 to the connecting portion to the first link member 61. Is set to

The transfer operation of the article M by the transfer feeder 7 is performed as shown in FIG. That is, FIG.
In the state where the article M is placed on the trough 25 as shown in (A), the linear motor 26 operates by energizing the coil 36 of the linear motor 26, and the moving body 38 moves in the direction Y ( 3B, the first link member 61 rotates counterclockwise about the support shaft 55, and the third link member 63 accordingly rotates the support shaft 52, as shown in FIG. 3B.
Rotate counterclockwise. Then, the second link member 62
Rotates counterclockwise about the support shaft 65, and the trough 25 moves in the transport direction X along the guide body 27 in response to this. At this time, the forward movement speed V _F of the trough 25 is such that its peak value does not overcome the static frictional resistance of the article M to the trough 25, thereby eliminating slippage between the article M and the trough 25. And efficiently convey the article M.

Next, when the shaft 40 moves to the left side in the figure due to the reverse operation of the linear motor 26, the first link member 61 rotates clockwise about the support shaft 55 as shown in FIG. Then, in response to this, the third link member 63 rotates clockwise about the support shaft 52. Then, the second link member 62 rotates clockwise about the support shaft 65, and accordingly, the trough 25 is moved along the guide body 27 in the transport direction X.
To the rear Y, which is opposite to the above. At this time, the retreat speed V _R of the trough 25 is such that its peak value overcomes the static frictional resistance of the article M to the trough 25, thereby minimizing the backward movement of the article M to the rear. Hereinafter, by repeating the reciprocating motion of the trough 25, the articles M are sequentially moved in the transport direction X and transported, and the articles M are thrown into the pool hopper (FIG. 1) of the measuring section on the tip side of the trough 25. You.

As described above, in the transfer feeder 7 having the above configuration, the load of the trough 25 is not applied to the moving body 38 of the linear motor 26, and the life of the linear motor 26 can be extended. Further, in the transport operation, as shown in FIG. 3B, when the trough 25 moves forward X, the weight 44 moves backward Y, and when the trough 25 moves backward Y, the weight 4 moves.
4 moves forward X, the inertial force of the trough 25 is canceled by the weight 44, and the vibration caused by the reciprocation of the trough 25 can be prevented from being generated in the base 41. The vibration causes the weighing accuracy of the combination weighing device to be reduced. Can be prevented from decreasing.

The moving body 3 in the linear motor 26
8 is substantially equal to the trough 25 on which the article M is placed, even if the weight 44 is omitted,
The moving body 38 that moves in the direction opposite to the above functions as vibration damping means for canceling the inertial force of the trough 25, so that it is possible to sufficiently prevent the base 41 from vibrating due to the reciprocation of the trough 25.

Further, in the transport operation, the third link member 63 which constitutes a part of the power transmission mechanism 28 is moved from the intermediate portion which is swingably supported around the support shaft 52 with respect to the support leg 51. A distance b from the intermediate portion to the other end connected to the second link member 62 is set longer than a distance a to one end connected to the first link member 61. Thereby, the reciprocating stroke of the trough 25 becomes
It becomes larger than the reciprocating stroke of the moving body 38 of the linear motor 26. That is, the moving body 3 of the linear motor 26
Exceeding the upper limit value of the reciprocating stroke of No. 8, the reciprocating stroke of the trough 25 can be set large. From this point,
The life of the linear motor 26 whose life is determined by the cumulative value of the reciprocating movement distance of the moving body 38 can be extended.

Further, the power transmission mechanism 28 is
And the three link members 61 to 63, so that the support position of the intermediate portion of the third link member 63 rotatably supported by the support leg 51 via the support shaft 52 is adjusted. As a result, the reciprocating stroke of the trough 25 is
A large value exceeding the upper limit displacement of the moving body 38 of the linear motor 26 can be easily set.

In the combination weighing apparatus shown in FIG. 1, the reciprocating motion of the plurality of transfer feeders 7 arranged radially is 1 to
Although it lasts several seconds, the operation timing of the reciprocating movement of each transfer feeder 7 is set so as to be shifted between adjacent transfer feeders 7 by a time shorter than the cycle time (for example, 0.1 second). Accordingly, it is possible to prevent the reciprocating timings of the plurality of transfer feeders 7 from being coincident with each other to cause a large vibration.

FIG. 4A shows the operation of the transfer feeder 7.
An example of the mode is shown. This mode of operation is, for example,
For transporting low-viscosity articles M such as
Therefore, the vertical axis indicates the moving speed and the moving acceleration of the trough 25.
And the horizontal axis represents time. In addition, the upper side of the vertical axis
Speed V_FAnd acceleration α_F, And the lower side is the speed V when retreating. _R
And acceleration α_RRepresents As described above, the reverse speed V
_RIs the forward speed V_FGreater than the peak value of
It is said. Note that, in FIG._FAnd after
Retreat speed V_ROf the part surrounded by the waveform of
The area (time integral of the waveform) is the reciprocating straw of the trough.
Represents Forward speed V_FArea and retreat speed V_Rof
The forward speed V is equal to the area of the part and has a small peak value._F
Time width T of waveform_FIs the reverse speed V having a large peak value._R
Time width T of waveform_RLonger than

FIG. 4B shows the operation of the transfer feeder 7.
7 shows another example of the mode. This mode of operation is for pickles and mochi
For transporting highly viscous articles M such as
And forward speed V_FThe peak value of FIG.
But the reverse speed V _RThe peak value of
The value is larger than that in the case of (A). With this,
Even when the product M is highly viscous,
The article M overcomes the large static friction resistance and
To the forward measuring section
The article M can be properly conveyed toward.

[0037] In FIG. 4, corresponding to the viscosity of the article M, there is shown the case where given difference such as reverse speed V _R and the reciprocating stroke of the trough 25, In addition, for example, to correspond to the transport quantity Te may be given differences such as the peak value and the reciprocating stroke of the reverse speed V _R.

In the transfer feeder 7, the operator
When control conditions corresponding to the type of the article M to be conveyed and a desired conveyance amount are set in the controller 29 by the control condition setting means 30 in FIG. 2, the linear motor 26 is controlled in an operation mode corresponding to the set control conditions. You. For this reason, even if the type of the article and the transport amount are changed, it is possible to appropriately transport the desired amount of the article to the measuring section according to the transport amount. Here, the controller 29 is controlled by the control condition setting means 30.
The reciprocating speed, the reciprocating acceleration, the reciprocating stroke, etc. of the transfer feeder 7 according to the control conditions set in the controller 29 are displayed as a waveform diagram as shown in FIG. Is done.

FIGS. 5A and 5B are side views showing another embodiment of the transfer feeder 7 which is a linear transfer device.
And a rear section view. This transfer feeder 7 is shown in FIG.
In the transfer feeder 7 according to the embodiment shown in FIG. 1, the power transmission mechanism 28 includes a support leg 51 erected on the base 41.
And one end is connected to the shaft 40 of the linear motor 26,
The other end is rotatably connected to the trough 25, and the intermediate portion is composed of a link member 53 rotatably supported on the support leg 51 about a support shaft 52. An elongate hole 53a is formed at one end of the link member 53 connected to the shaft 40, and a support shaft 55 protrudes from a side surface of the connection body 54 fixed to the shaft 40. The long hole 53a engages with 55. Accordingly, with the linear movement of the shaft 40, the support shaft 55 slides in the elongated hole 53a, and the link member 53 swings about the support shaft 52.

The trough 2 of the link member 53
A long shaft 53b is also formed at the other end connected to the support member 5, and a support shaft 57 is provided on a side surface of a support member 56 protruding downward at one side of the trough 25, The elongated hole 53b is engaged with the support shaft 57. Accordingly, with the swing of the link member 52, the support shaft 57 slides in the long hole 53b, and the trough 25 is moved back and forth in the transport direction X-Y.
To reciprocate.

Also in this case, the link member 53 has a distance A from an intermediate portion supported by the support leg 51 so as to be swingable around the support shaft 52 to one end connected to the shaft 40 of the linear motor 26. Than the trough 2
The distance B to the other end connected to No. 5 is set to be longer.

FIG. 6 shows a transport operation by the transfer feeder 7. In this case, FIG.
When the shaft 40 moves to the left side in the figure by the operation of the linear motor 26 from the state shown in FIG. 6A, the link member 53 constituting the power transmission mechanism 28 becomes the support shaft 52 of the support leg 51 as shown in FIG. Swings counterclockwise around. Accordingly, the trough 25 has a velocity V having a peak value that does not overcome the static friction resistance of the article M against the trough 25.
_{At F} , it moves in the transport direction X along the guide 27. Note that only a part of the article M is displayed for easy understanding.

Next, by the reverse operation of the linear motor 26,
As shown in FIG. 6C, the forward speed V is set so that the trough 25 overcomes the static friction resistance of the article M against the trough 25.
A speed V _R with _F greater than the peak value moves rearward Y. As a result, the article M slides relatively forward X on the trough 25 while receiving a dynamic frictional resistance smaller than the static frictional resistance. Hereinafter, by repeating the reciprocating movement of the trough 25, the articles M are sequentially moved in the transport direction X and transported, and the articles M are put into the pool hopper 9 (FIG. 1) of the measuring section on the tip side of the trough 25. Is done. According to this configuration, the same effect as in the above embodiment can be obtained.

Also, since the distance B is set to be longer than the distance A in the link member 53,
The reciprocating stroke of the trough 25 is larger than the reciprocating stroke of the moving body 38 of the rear air motor 26. Here, since the power transmission mechanism 28 has a simple structure in which the link member 53 is swingably supported around the support shaft 52 at an intermediate portion thereof, the reciprocating stroke of the trough 25 is reduced by the moving body of the linear motor 26. It can be easily set to a large value exceeding the upper limit value of the reciprocating stroke of 38.

[0045]

As described above, according to the linear transport apparatus of the present invention, a trough on which articles are placed, a linear motor, and a guide body for guiding the trough back and forth in the transport direction.
By connecting the moving body of the linear motor and the trough,
A power transmission mechanism for reciprocating the trough in the transport direction along the guide in a direction opposite to the moving direction by the movement of the moving body, and controlling the linear motor to convey articles by reciprocating the trough. And the controller that drives the linear motor, the weight of the trough is not applied to the moving body of the linear motor, so that the life of the linear motor can be extended and the trough reciprocates in the direction opposite to the moving direction of the moving body of the linear motor. Can be canceled, and the vibration applied to the base supporting the transfer device due to the reciprocation of the trough can be sufficiently reduced. Further, since the linear movement of the moving body of the linear motor is transmitted to the trough via the power transmission mechanism, the reciprocating stroke of the trough can be set to be larger than the upper limit displacement of the moving body of the linear motor.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing a combination weighing device using a linear transfer device according to an embodiment of the present invention.

FIG. 2A is a side view showing the transport device, and FIG. 2B is a rear cross-sectional view of the transport device.

FIG. 3 is a side view showing a transfer operation of the transfer device.

FIGS. 4A and 4B are characteristic diagrams showing an example of an operation mode in the transport apparatus.

FIG. 5A is a side view of a linear transfer device according to another embodiment of the present invention, and FIG. 5B is a rear cross-sectional view of the transfer device.

FIG. 6 is a side view showing a transfer operation of the transfer device.

[Explanation of symbols]

7: transfer feeder (linear transfer device), 25: trough,
26: Linear motor, 27: Guide, 28: Power transmission mechanism, 29: Controller, 30: Control condition setting means, 3
5 housing, 36 coil, 37 magnet, 38 moving body, 40 shaft, 44 weight, 61 first link member, 62 second link member, 63 third link member,
M… Article

Claims (5)

[Claims] 1. A trough on which an article is placed, a linear motor, a guide body for guiding the trough back and forth in a transport direction, and a moving body of the linear motor and the trough connected to each other.
A power transmission mechanism for reciprocating the trough in the transport direction along the guide in a direction opposite to the moving direction by the movement of the moving body, and controlling the linear motor to convey articles by reciprocating the trough. And a controller for controlling the linear transfer. 2. The linear transport device according to claim 1, further comprising control condition setting means for setting a control condition according to a type of the article in the controller. 3. The power transmission mechanism according to claim 1, wherein one end of the power transmission mechanism is rotatably connected to the movable body, and one end of the power transmission mechanism is rotatably connected to the trough. A second link member, one end of which is rotatably connected to the other end of the first link member, and the other end of which is rotatably connected to the other end of the second link member. A linear transfer device having a third link member rotatably supported. 4. The linear transport device according to claim 1, wherein a weight that cancels the inertial force of the trough is fixed to the moving body. 5. The linear motor according to claim 1, wherein the linear motor includes a coil fixed to a housing, a shaft supported by the housing so as to be linearly movable to form the moving body, A linear transfer device which is a linear stepping motor having a fixed magnet.