JP2013224198A - Lift device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lift device capable of estimating weight of a load placed on a ramp without adding a special weight sensor, based on which control of an elevating operation of a ramp can be performed.SOLUTION: A lift device includes: a ramp 9 that is supported in a manner to freely go up and down along a frame 3; an endless chain 17 for suspending the ramp; a geared motor 11 for causing the ramp to go up and down through the endless chain: a linear scale 100 for detecting a height position of the ramp; a displacement amount measuring means 110 for measuring a displacement amount of the height position of the ramp by the elongation of the endless chain before and after a load W is placed on the ramp as a value equivalent to the weight of the load based on the output of the linear scale; and a going up and down speed control means 120 for switching the going up and down speed patterns of the ramp by the geared motor according to the displacement amount measured by the displacement amount measuring means.

Description

  The present invention relates to a lift device (also referred to as a lifter or an elevator) used to carry in and out a load (workpiece or product) with respect to storage shelves provided in a plurality of stages in the height direction, for example.

  A shelf device provided with this type of lift device is described in Patent Document 1. This lifting device has a lifting platform that can be moved up and down along the frame, and the lifting platform is connected to a part of an endless chain wound around a sprocket on the upper and lower ends of the frame, thereby It is configured to be lifted and lowered by suspending and supporting by an endless chain and driving the endless chain by a geared motor. In this type of lift device, the lifting speed pattern of the lifting platform is switched in two ways: when the pallet is not placed on the lifting platform and when it is placed.

JP 2010-235221 A

  By the way, even when the pallet is placed on the lifting platform, in fact, there are many cases where there is a large difference in the weight of the load on the pallet. Conventionally, an ascending / descending speed pattern for setting a pallet is set according to the maximum weight of the load on the pallet. Therefore, in the case of a heavy baggage and a light baggage, the lifting platform is moved up and down at the same speed pattern, and in the case of a light baggage, there is a problem that the conveyance efficiency is deteriorated. For example, even if the weight of the luggage is 10 kg or 2 tons, since it is operated with the same lifting speed pattern, the lifting operation is too slow in the case of a light luggage, and the efficiency is poor. .

  Therefore, the idea of measuring the weight of the luggage in advance and changing the lifting speed pattern according to the weight of the luggage comes out, but measuring the weight of the luggage in advance is cumbersome and causes complicated work. There is a fear. In addition, it is conceivable to separately provide a weight sensor for detecting the load weight on the lifting platform or the like, but there is a problem that the cost is high.

  In consideration of the above circumstances, the present invention can estimate the weight of the load placed on the lifting platform without adding a special weight sensor, and can perform lifting operation control of the lifting platform based on the weight. An object is to provide an apparatus.

  In order to solve the above-described problems, a lift device according to a first aspect of the present invention includes a lifting platform that is supported so as to be movable up and down along a frame, a rope that suspends the lifting platform, and a lift that is raised and lowered via the rope. A drive mechanism that raises and lowers the table, a height position detection unit that detects the height position of the table, and a load output on the platform based on the detection output of the height position detection unit Displacement measuring means for measuring the amount of displacement of the height position of the lifting platform due to the elongation of the rope later as a value corresponding to the weight of the load is provided.

  According to a second aspect of the present invention, there is provided the lift device according to the first aspect, wherein the lifting speed control means for switching a lifting speed pattern of the lifting platform by the drive mechanism according to the displacement amount measured by the displacement amount measuring means. Furthermore, it is characterized by comprising.

  A third aspect of the present invention is the lift device according to the first or second aspect, wherein an endless chain as the rope is wound around sprockets provided at an upper end and a lower end of the frame. The lifting platform is connected to a portion, and the drive mechanism is provided so as to drive the endless chain around.

  A fourth aspect of the present invention is the lift device according to any one of the first to third aspects, wherein the height position detecting means is a scale disposed on the frame and disposed on the lifting platform. And a linear scale comprising a detector for obtaining height information from the scale.

  According to the first aspect of the present invention, since the height position detecting means for detecting the height position of the lifting platform is provided, the stop height of the lifting platform can be accurately controlled according to the height of the storage shelf or the like. . In addition, based on the detection output of the height position detecting means, the displacement amount measuring means calculates the amount of displacement of the height position of the lifting platform due to the elongation of the cable material before and after the loading material is placed on the lifting platform. Therefore, it is possible to estimate the weight of the load without using a special weight sensor, and the transport efficiency can be improved by controlling the lifting operation of the lifting platform according to the estimated value. I can plan.

  According to the second aspect of the present invention, the lifting speed control means has the lifting speed pattern of the lifting platform according to the amount of displacement of the height position of the lifting platform due to the elongation of the rope before and after placing the load on the lifting platform. Therefore, the lifting platform can be raised and lowered with an optimum speed pattern according to the weight of the load, and the conveyance efficiency can be improved.

  According to the invention of claim 3, it is possible to estimate the weight of the load by detecting a slight elongation of the chain before and after the load is placed on the lifting platform. The lifting platform can be raised and lowered with an optimal speed pattern.

  According to invention of Claim 4, the displacement of the height position of the raising / lowering stand by the linear elongation according to the weight of a load can be detected correctly with a linear scale.

It is a side view which shows the principle structure of the lift apparatus of embodiment of this invention. In the lift apparatus, it is a side view which exaggerates a mode that a raising / lowering stand displaces according to the weight of a load. In the same lift device, it is a chart showing the relationship between the extension amount of the chain when the lifting platform is displaced according to the weight of the load, the loading weight, and the acceleration / deceleration and the speed of the lifting platform changed accordingly. It is a graph which shows the kind of raising / lowering speed pattern selected according to a weight in the lift apparatus. It is a flowchart which shows the flow of control in the same lift apparatus, when selecting a raising / lowering speed pattern according to a weight. It is a side view which shows the whole outline | summary of the shelf apparatus incorporating the said lift apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view showing a principle configuration of a lift device according to an embodiment.

  The lifting device M includes a lifting platform 9 supported so as to be movable up and down along the frame 3, an endless chain (line material) 17 that suspends the lifting platform 9, and an endless chain 17 that is driven around. A geared motor (driving mechanism) 11 that raises and lowers the vehicle, a linear scale (height position detecting means) 100 that detects the height position of the elevator 9, and a load W on the elevator 9 based on the detection output of the linear scale 100. The displacement amount measuring means 110 for measuring the amount of displacement of the height position of the lifting platform 9 due to the extension of the endless chain 17 before and after placing as a weight equivalent value of the load W, and the displacement amount measuring means 110 were measured. Elevating speed control means 120 that switches the elevating speed pattern of the elevator 9 by the geared motor 11 according to the amount of displacement is provided.

  The endless chain 17 is wound around sprockets 13 and 15 arranged at the upper and lower ends of the frame 3, and the lifting platform 9 is connected to a part of the endless chain 17. Then, by driving the sprocket 13 at the upper end by the geared motor 11, the endless chain 17 is made to circulate and the lifting platform 9 is moved up and down. The linear scale 100 includes a scale 100A disposed on the frame 3 and a detector 100B disposed on the lifting platform 9 and acquiring height information using the scale 100A.

  The rotational speed of the geared motor 11 is controlled by an inverter 130, and the lifting speed of the lifting platform 9 by the geared motor 11 can be controlled by inputting a lifting speed pattern switching signal from the lifting speed control means 120 to the inverter 130. .

  FIG. 2 shows exaggeratedly how the lifting platform 9 is displaced by the extension of the endless chain 17 in accordance with the weight of the load in the lift device M.

  Assuming that the height before the load W is placed on the lift 9 (when there is no load) is the reference height A, the endless chain 17 extends as the weight of the load W increases. The height position of is greatly displaced. If the detected value of the linear scale 100 at the position A is read, the displacement amount H from the reference height A can be measured more easily than the linear scale 100. Now, assuming that the lift 9 is lowered to the positions B, C, and D according to the weight of the load W, the weight of the load W can be estimated according to the amount of displacement.

  FIG. 3 shows the relationship between the extension amount of the endless chain 17 when the lifting platform 9 is displaced according to the weight of the load W, the loading weight, and the acceleration / deceleration and speed of the lifting platform 9 that are changed accordingly. ing. FIG. 4 shows the types of lifting speed patterns to be selected according to the estimated weight.

  The elongation A is in the range of about 0 to 0.5 mm. At this time, since the load weight can be estimated to be light (less than 500 kg), the vehicle is operated with the speed pattern A (speed pattern with the maximum acceleration / deceleration and the maximum speed) set when there is no load.

  The elongation amount B is in the range of about 0.5 to 1.0 mm. At this time, since it can be estimated that the loaded weight is about 500 kg, the vehicle is operated with the speed pattern B (medium acceleration / deceleration and the maximum speed × 0.8 speed pattern).

  The elongation C is in the range of about 1.1 to 1.5 mm. At this time, since it can be estimated that the loaded weight is about 1 ton, the vehicle is operated with a speed pattern C (a speed pattern with medium acceleration / deceleration and maximum speed × 0.7 speed pattern).

  The elongation amount D is 1.5 mm or more. At this time, since it can be estimated that the loaded weight is 1.5 ton or more, the vehicle is operated with a speed pattern D (speed pattern with a small acceleration / deceleration and a maximum speed × 0.6).

  The actual control is performed according to the flowchart shown in FIG.

  First, when the process is started, the value of the linear scale 100 before loading the load immediately before driving is read in step S1. Next, in step S2, the value of the linear scale 100 in a state where the load is placed is read, and the extension amount of the endless chain 17 is measured.

  Next, in step S3, a lifting speed pattern corresponding to the amount of elongation of the endless chain 17 is selected from A to D. In step S4, the inverter 130 is commanded to drive the lifting platform 9 with the selected lifting speed patterns A to D. By performing this process every time the load is transported, it is possible to operate with an optimum speed pattern corresponding to the weight.

  According to the lift device M having such a configuration, the following operational effects can be obtained.

  First, since the linear scale 100 that detects the height position of the lifting platform 9 is provided, the stop height of the lifting platform 9 can be accurately controlled according to the height of the storage shelf or the like. Moreover, based on the detection output of the linear scale 100, the displacement of the height position of the lifting platform 9 due to the extension of the endless chain 17 before and after the displacement measuring means 110 places the load W on the lifting platform 9. Is measured as the weight equivalent value of the load W, so that the weight of the load W can be estimated without using a special weight sensor.

  The lifting speed control means 120 changes the lifting speed pattern of the lifting platform 9 according to the amount of displacement of the height position of the lifting platform 9 due to the extension of the endless chain 17 before and after the load W is placed on the lifting platform 9. Since the switching is performed, the lifting platform 9 can be moved up and down at an optimum speed pattern according to the weight of the load W, and the conveyance efficiency can be improved. Moreover, since the raising / lowering time can be shortened and the conveyance efficiency is improved, a reduction in power consumption can be expected.

  Next, an application example of the lift device M of the present embodiment will be described.

  FIG. 6 is a side view showing an overall outline of the shelf device 1 in which the lift device M is incorporated. The same elements as those described in FIG. 1 are denoted by the same reference numerals in FIG. In FIG. 6, the X direction is referred to as the left-right direction of the shelf device, and the Y direction is referred to as the front-rear direction of the shelf device.

  The shelf device 1 includes a frame 3 having a frame structure. The frame 3 is provided with a plurality of stages of storage shelves 5 for allowing a pallet P on which loads such as plate-shaped workpieces and plate-shaped products are loaded to enter and exit in the front-rear direction (left-right direction = Y direction in FIG. 6). Yes. That is, a plurality of storage shelves 5 are configured by providing a plurality of guide rails 7 for guiding the pallet P in the front-rear direction inside the frame 3 so as to face in the left-right direction (X direction).

  In addition, the lift device M according to the embodiment is provided on the front side of the frame 3 in order to load and unload the pallet P with respect to each storage shelf 5. The lift device M includes a lifting platform 9 that is supported by the frame 3 so as to be movable up and down. A drive-side sprocket 13 and a driven-side sprocket 15 that are rotated by a geared motor 11 for raising and lowering are rotatably disposed on the front side, top, bottom, left and right of the frame 3, and an endless chain 17 is wound around these sprockets 13 and 15. The lifting platform 9 is connected to a part of the endless chain 17. Further, a linear scale 100 (not shown in FIG. 6) for detecting the height position of the elevator 9 is provided between the elevator 9 and the frame 3. The other components of the lift device M are not shown.

  The elevating platform 9 is provided with a traverser 19 provided with a locking portion that can be locked from below on the front edge of the pallet P so as to be movable in the front-rear direction. Accordingly, the geared motor 11 for raising and lowering is appropriately driven to raise and lower the elevator 9 via the endless chain 17, and after the elevator 9 is positioned and stopped at a height corresponding to the desired storage shelf 5, the traverser 19 The pallet P in the storage shelf 5 can be pulled out on the lifting platform 9. Conversely, when the pallet P is placed on the lifting platform 9, the pallet P on the lifting platform 9 is stored in the frame 3 in a desired manner. It can be stored (accommodated) in the shelf 5.

  A work pallet housing shelf 5 </ b> A for housing the pallet P on which the work Wa is placed is provided at the lower part of the frame 3. That is, a guide rail 7 is provided at the lower part of the frame 3, and a work pallet storage shelf 5 </ b> A is formed above the guide rail 7. A single picking device 21 for picking up a single piece of work Wa loaded on the pallet P is provided at the top of the work pallet storage shelf 5A so as to be movable up and down. In addition, since the structure of this kind of single picking apparatus 21 is known, description about the single picking apparatus 21 is abbreviate | omitted.

  In order to support the workpiece Wa picked up by the single picking device 21, a movable table 23 that can reciprocate between the vertically moving region of the lifting platform 9 and the lower position of the raised single picking device 21 is provided. Is provided. More specifically, at a position higher than the pallet P accommodated in the work pallet accommodating shelf 5A, a slider 25 supporting the moving table 23 on the upper side is provided in the work pallet accommodating shelf 5A so as to be movable back and forth. Yes. Further, a reciprocating device for reciprocating the slider 25 in the front-rear direction is provided.

  The slider 25 is movable to front and rear guide members (not shown) horizontally provided on the left and right sides in the work pallet storage shelf 5A, and the space (region) in which the lifting platform 9 moves up and down from the work pallet storage shelf 5A. It is supported so that it can protrude inward. In other words, the moving table 23 is provided so as to protrude from the work pallet storage shelf 5 </ b> A to the front side of the frame 3. As a configuration of the reciprocating operation device, a fluid pressure cylinder such as an air cylinder can be adopted, but in this example, the configuration is as follows.

  That is, drive sprockets 29 that are rotated forward and backward by the motor 27 are rotatably provided on the left and right sides of the work pallet storage shelf 5A. A driven sprocket 31 corresponding to the drive sprocket 29 is rotatably provided on both the left and right sides of the front side of the work pallet storage shelf 5A. An endless chain 33 is wound around the driven sprocket 31 and the drive sprocket 29. The endless chain 33 and the rear end of the slider 25 are connected.

  Accordingly, when the motor 27 is driven to rotate the endless chain 33 in the forward direction, the moving table 23 moves to the left in the figure via the slider 25 and moves to the front side of the frame 3 in the region where the lifting platform 9 moves up and down. Protruding. Further, by rotating the endless chain 33 in the reverse direction, the moving table 23 protruding into the vertical movement region of the lifting platform 9 is drawn into the work pallet storage shelf 5A at the lower position of the single picking device 21 in the raised state. be able to.

  When the single workpiece picking device 21 picks up one workpiece W on the pallet P in the work pallet receiving shelf 5A, the movable table 23 is projected to the vertical movement area of the lifting platform 9 (front side of the frame 3). The top of the pallet P is opened. In this state, the single picking device 21 can pick up the work Wa on the pallet P without interfering with the moving table 23.

  When the single picking device 21 picks up the workpiece Wa and moves up, the moving table 23 is pulled to a position below the single picking device 21 and the work Wa is placed on the moving table 23. The work Wa placed on the moving table 23 is moved by the conveying means 35 provided in the work pallet receiving shelf 5A so as to be movable in the left-right direction (X-axis direction) at substantially the same height as the single-sheet pick-up device 21. Then, it is conveyed to a plate material processing machine (not shown) arranged adjacent in the left-right direction and processed by the plate material processing machine.

  Since the structure of the conveying means 35 is well known, the detailed description of the conveying means 35 is omitted. The conveying means 35 has a function of supplying and carrying a workpiece to and from the plate material processing machine and a function of carrying out a product processed by the plate material processing machine from the plate material processing machine.

  When the workpiece Wa carried into the plate material processing machine is processed by the transport means 35, the processed product is transported onto the moving table 23 by the transport means 35. In order to load the processed product on the pallet P, an empty pallet P taken out from an appropriate storage shelf 5 of the frame 3 is placed in advance on the lifting platform 9. And in order to load the product on the moving table 23 on the pallet P, the lifting platform 9 is positioned in a state where it is lowered to a position lower than the height position at which the moving table 23 protrudes.

  When the lifting / lowering base 9 is lowered to a low position, the moving table 23 with the product placed thereon is projected from the work pallet storage shelf 5A to the upper position of the lifting / lowering base 9. Thereafter, product transfer means for transferring the product on the movement table 23 onto the product pallet P when the movement table 23 is pulled into the work pallet storage shelf 5A is provided.

  As the product transfer means, it is possible to adopt a transfer robot that holds the product on the moving table 23 and transfers it onto the product pallet P. However, in the present embodiment, a configuration is adopted in which the product on the moving table 23 is prevented from returning integrally when the protruding moving table 23 returns to the work pallet receiving shelf 5A. That is, a vertical operation device 37 such as a fluid pressure cylinder is provided on the upper side of the moving table 23 and in front of the work pallet storage shelf 5A. A stopper member 39 is provided on a piston rod that moves up and down in the vertical operation device 37. Is provided.

  Therefore, when the moving table 23 on which the product is placed is in a state of protruding above the pallet P placed on the lifting platform 9, the moving table 23 is in a state where the stopper member 39 is lowered to prevent the product from returning. Is returned to the work pallet storage shelf 5A, and the product on the moving table 23 can be dropped and loaded on the pallet P on the lifting platform 9.

  The work Wa on the pallet P in the work pallet storage shelf 5A is supplied and carried into the plate material processing machine, the processed product is unloaded and loaded on the pallet P on the lifting platform 9 repeatedly. When the workpiece Wa is removed and the machining is completed, the lifting platform 9 is raised, and the pallet P loaded with products is stored in the empty storage shelf 5. Thereafter, the lifting platform 9 is lowered to take out the empty pallet P in the work pallet storage shelf 5 </ b> A onto the lifting platform 9 and store this pallet P in a separate empty storage shelf 5.

  Next, the lifting platform 9 is positioned at a position corresponding to the storage shelf 5 in which the pallet P loaded with workpieces to be processed is stored (stored), and the pallet P is moved onto the lifting platform 9. Then, the pallet P is stored in the work pallet storage shelf 5A, the next workpiece is supplied and carried into the plate material processing machine, and the processing of the next workpiece is started. As described above, when processing of the next workpiece is started, the lifting platform 9 takes out the above-described empty pallet P, and uses this pallet P as a product pallet P on which the next product is loaded.

  By applying the lift device M of the present embodiment to the shelf device 1 as described above, the conveyance efficiency can be improved. Here, the load W placed on the lifting platform 9 is a pallet P alone, a combination of the pallet P and the workpiece Wa, a combination of the pallet P and the product, or the like.

  In the above-described embodiment, the case where an endless chain is used as the rope member has been shown, but a steel wire or the like with little axial extension can also be used.

M Lift device W Load 3 Frame 9 Lifting table 11 Geared motor (drive mechanism)
13, 15 Sprocket 17 Endless chain (Rope)
100 linear scale (height position detection means)
100A scale 100B detector 110 displacement measuring means

Claims (4)

A lifting platform supported so as to be movable up and down along the frame;
A rope for suspending the lifting platform;
A drive mechanism for raising and lowering the lifting platform via the rope;
A height position detecting means for detecting a height position of the lifting platform;
Based on the detection output of the height position detection means, the amount of displacement of the height position of the lifting platform due to the extension of the cable material before and after loading the loading table on the lifting platform is equivalent to the weight of the loading object. Displacement amount measuring means for measuring as
A lift device comprising: The lift device according to claim 1,
The lift apparatus further comprising a lifting speed control means for switching a lifting speed pattern of the lifting platform by the drive mechanism in accordance with the displacement amount measured by the displacement amount measuring means. The lift device according to claim 1 or 2,
An endless chain as the rope is wound around sprockets provided at the upper and lower ends of the frame, the lifting platform is connected to a part of the endless chain, and the driving mechanism drives the endless chain to circulate. A lift device characterized by being provided. It is a lift device given in any 1 paragraph of Claims 1-3,
As the height position detecting means, there is provided a linear scale comprising a scale disposed on the frame and a detector disposed on the lifting platform for obtaining height information by the scale. Lift device characterized.

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