JP2004307113A

JP2004307113A - Lift controller

Info

Publication number: JP2004307113A
Application number: JP2003100980A
Authority: JP
Inventors: Yoji Nakano; 陽二中野
Original assignee: Atex Co Ltd
Current assignee: Atex Co Ltd
Priority date: 2003-04-04
Filing date: 2003-04-04
Publication date: 2004-11-04
Anticipated expiration: 2023-04-04
Also published as: JP3968582B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lift controller that does not generate large error in a lifting body stopping position due to presence or absence of load in the lifting body or difference in the lifting direction, can certainly stop the lifting body at a certain position, and has high lifting speed and high working efficiency. <P>SOLUTION: When a position detecting means 4 gets into a detection state while the lifting body 2 is lifting, a control means 3 performs control to output a reverse braking signal to a motor 1 to stop the lifting body 2 in a short time. The lift controller has a load detecting means 5 for determining the presence or absence of the load in the lifting body 2. When the lifting body is lifted up in a presence state of the load, the reverse braking to the motor 1 is not performed even when the position detecting means 4 gets into the detection state. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、載置状態、又は吊下状態の荷物を、昇降体の昇降によって昇降させることのできる昇降装置に関するものであり、更に詳しくは、モータ駆動によって昇降する昇降体の昇降制御装置に関するものである。
【０００２】
【従来の技術】
【引用文献１】実開平６−３５２９７号公報
米や麦等の穀類収納袋を適宜の高さまで持ち上げる昇降作業台が引用文献１に記載されている。これは、下降限に待機させた袋載せ台に穀類収納袋を載せた後、袋載せ台を上昇させて、例えば袋結びが容易な高さや運び出しが容易な高さで袋載せ台を停止させることのできるものである。袋載せ台の各停止位置は検出器により検出され、引用文献１の実施例にあっては袋載せ台背後壁に設けた検出部が支柱側のリミットスイッチをＯＮ動作させて袋載せ台を停止する構成である。
昇降装置の作業効率を上げるためには昇降速度を速くすることが有効な手段ではあるが、その場合袋載せ台の検出部がリミットスイッチをＯＮ動作させ駆動モータの停止信号が出力された後に、袋載せ台が慣性力の作用によって更に移動してしまうため完全に停止するまでの移動量が大きくなり、又、積荷状態と空荷状態とでは袋載せ台の停止する高さ位置が異なるという不都合があるものであった。この袋載せ台停止位置の誤差は、荷物を載せた状態の上昇時と下降時とを比較すると最も大きくなる。更に、検出部がリミットスイッチをＯＮ動作しても袋載せ台がすぐには停止せず、リミットスイッチの作動範囲を検出部が通過して再びリミットスイッチがＯＦＦ動作となるオーバーリミット状態を解消するため、リミットスイッチをＯＮ動作させる検出部の作動平面を長く構成しなければならず、この作動平面の途中で袋載せ台を停止させること、すなわち袋載せ台を少しだけ昇降して停止させる制御が困難であった。
【０００３】
【発明が解決しようとする課題】
本発明は、上記不都合を解消し、昇降条件の違いによって昇降体の停止位置に大きな誤差が生じることがない作業効率の良い昇降装置の昇降制御装置を提供することを課題とする。
【０００４】
【課題を解決するための手段】
請求項１に記載の発明は、モータ１駆動による昇降自在の昇降体２と、該モータ１の駆動制御を行う制御手段３と、前記昇降体２を所定高さに停止させる位置検知手段４とを備えた昇降装置において、昇降体２昇降中に位置検知手段４が検知状態となれば、制御手段３がモータ１への逆転制動信号を出力して昇降体２を短時間で停止させることを特徴とする昇降制御装置の構成とする。
請求項２に記載の発明は、昇降体２の荷物の有無を判断する荷物判断手段５を設け、昇降体２に荷物が有る状態で上昇させた場合に、位置検知手段４が検知状態となっても制御手段３はモータ１への逆転制動信号を出力しないことを特徴とする昇降制御装置の構成とする。
請求項３に記載の発明は、モータ１駆動電流Ｉの大小によって昇降体２の荷物の有無を判断する荷物判断手段５において、モータ１駆動開始後、所定時間Ｔ経過前に位置検知手段４が検知状態になる場合は、該荷物判断手段５の判断結果にかかわらず、制御手段３がモータ１への逆転制動信号を出力することを特徴とする昇降制御装置の構成とする。
【０００５】
【発明の作用及び効果】
請求項１の発明にあっては、昇降体２昇降中に位置検知手段４が検知状態となれば、制御手段３がモータ１への逆転制動信号を出力し、昇降体２を極短時間で停止させることができるので、昇降体２の昇降速度を速くすることが可能であるとともに、昇降体２停止位置の誤差が少なく、又、昇降体２がオーバーリミット状態となることのない確実な停止を行うことができ、作業効率の良い昇降制御が可能となる。
請求項２の発明にあっては、昇降体２の荷物の有無を判断する荷物判断手段５を設け、昇降体２に荷物が有る状態で上昇させた場合に、位置検知手段４が検知状態となっても制御手段３がモータ１への逆転制動信号を出力しないものである。これは、下方への大きな重力が加わっている状態の昇降体２を上昇させて停止する場合には、モータ１に対する慣性力の作用が少なく、この時にモータ１を逆転制動させると、昇降体２を下降させた場合の停止位置とは異なる位置で停止するという不都合を解消できるものであり、昇降体２の昇降条件による停止位置の誤差をより少なくすることができる。
請求項３の発明にあっては、モータ１の駆動電流Ｉの大小によって昇降体２の荷物の有無を判断する荷物判断手段５は、モータ１の駆動電流Ｉが大きい場合に荷物有りと判断し、所定電流値が小さい場合には空荷と判断する構成であるが、モータ１起動直後の駆動電流Ｉは荷物の有無にかかわらず大きいため、空荷状態での上昇開始時にも荷物判断手段５が荷物有りの誤った判断を行うこととなり、この時昇降体２を上昇させ停止させるまでの上昇量が少ない設定の場合は、荷物判断手段５が荷物有りという判断をして、制御手段３がモータ１への逆転制御信号を出力せず、昇降体２が、停止させたい位置よりも高い位置に停止することとなり、オーバーリミット状態に至ることもある。本発明ではモータ１を駆動し昇降体２が上昇を開始してから、所定時間Ｔが経過する前に位置検知手段４が検知状態になる場合は、荷物判断手段５の判断結果にかかわらず、制御手段３がモータ１への逆転制動信号を出力して、昇降体２を短時間で確実に停止させるので、昇降体２の荷物の有無や昇降方向の条件による停止位置の誤差を少なくすることができる。
【０００６】
【発明の実施の形態】
次に、本件発明の実施の形態について図面に基づいて説明する。図１、図２に示すように平面視四角形状の基台１０から上方に向けて角パイプ材の支柱１１を立設し、支柱１１に沿って昇降自在の昇降体２を設けてある。支柱１１は前方の第１支柱１１ａとその後方に並設した第２支柱１１ｂとからなり、昇降体２の昇降枠１２は第１支柱１１ａを囲う形状とし、昇降枠１２前面下方には前方に向かって突設するテーブル１３を設け、該テーブル１３上に穀粒袋やダンボール等を載置して昇降させることが可能に構成してある。
第１支柱１１ａ後方に並設の第２支柱１１ｂの各々上端部は連結材１４で連結してある。第２支柱１１ｂの下端部と基台１０との間には昇降体２を昇降駆動するモータ１の出力部を配置し、第２支柱１１ｂ下端部の左右両側には湾曲形状の連結杆１５を溶着し、その後端部を基台１０に、その前端部を第１支柱１１ａ下部に溶着してある。
【０００７】
支柱１１下側に位置したモータ１の出力軸１６には駆動スプロケット１７を取着し、支柱１１上端部の連結材１４には従動スプロケット１８を軸支し、該駆動スプロケット１７と従動スプロケット１８の外周後端部は、角パイプ形状の第２支柱１１ｂ内部中央に位置させ、駆動スプロケット１７と従動スプロケット１８との間にチェン１９を巻き掛けてある。すなわち、チェン１９が第２支柱１１ｂの内部を挿通した形態にして、チェン１９にゴミやほこりが付着することを防止してある。該チェン１９両端は昇降体２の後側に連結して、モータ１が回転することで昇降体２が上下方向に可動するよう構成してある。本実施の形態では、モータ１の駆動電源に交流を使用しているが、バッテリ等からの直流電源で駆動しても良い。２０はチェン１９の緩み側を弾発するスプリングであり、２１はスプリング２０の弾発力を調整する調整ネジである。支柱１１の中間高さ位置には、左右に突出した昇降スイッチ２２を設け、該昇降スイッチ２２を操作することにより、昇降体２の昇降操作が可能である。制御手段３は第２支柱１１ｂ後方下部に取着のコントロールボックス２３内に設けてあり、モータ１の駆動制御やその他昇降装置全体の制御を行うことができる。コントロールボックス２３上方の３３は電源スイッチである。
【０００８】
第２支柱１１ｂの左右一側には昇降体２の位置を検知する位置検知手段４を設けてあり、本実施の形態ではリミットスイッチ２４，２５，２６，２７で各々の位置を検知するよう構成してある。各リミットスイッチ２４，２５，２６，２７は、昇降体２を人の肩高さに上昇させる上限設定位置Ｈのリミットスイッチ２４と、腰高さまで上昇させて搬出するに適した中間作業位置Ｍのリミットスイッチ２５と、穀粒袋等の袋口を結ぶのに適した袋結び位置Ｆのリミットスイッチ２６と、最下端となる下限設定位置Ｌのリミットスイッチ２７とからなり、昇降枠１２後部から突出するカム板２８が昇降することによってリミットスイッチ２４，２５，２６，２７を作動させる。これら各リミットスイッチ２４，２５，２６，２７は、作業条件に応じて上下取付高さ位置を変更可能に構成してある。２９はカバーであり、箱状に形成され、第１支柱１１ａ及び第２支柱１１ｂの左右両外側を覆ってある。
【０００９】
支柱１１上下中間部の昇降スイッチ２２を操作するとモータ１が駆動して昇降体２を昇降させる。尚、昇降スイッチ２２の操作方法や昇降体２の停止位置については作業形態に応じて適宜選択できるようにしても良い。又、昇降スイッチ２２は他の任意の位置に設けても良く、足踏み式のスイッチ等に変更も可能である。
次に米の選別機における作業を例に昇降装置の制御について図１，図６を参照に説明する。最初昇降体３は下限設定位置Ｌで停止している。この時、下側のリミットスイッチ２７はＯＮの状態であり、物品を載せる前の待機状態である。選別機で所定量（略３０ｋｇ）の米が袋に入ると、作業者は米袋を昇降体２のテーブル１３上に載せて、昇降スイッチ２２をＯＮ操作する。昇降スイッチ２２は、下方に１回だけ倒せばＯＮとなり、昇降スイッチ２２が元の水平状態に復帰してもＯＮ動作は保持されてモータ１が駆動する。昇降体２が米袋と共に上昇し始めると、下限のリミットスイッチ２０がＯＦＦとなり、昇降体２が上昇して袋結び位置Ｆに到達すると、すなわち、昇降体２後部のカム板２８がリミットスイッチ２６をＯＮにするとモータ１の駆動が停止する。この位置で作業者は袋の口にあるひもを結び、米袋をテーブル１３上で倒した後、再び昇降スイッチ２２をＯＮ操作する。すると昇降体２は再び上昇し、リミットスイッチ２５がＯＮとなる腰高さの中間作業位置Ｍ、又は、リミットスイッチ２４がＯＮとなる肩高さの上限設定位置Ｈで停止する。本実施例では中間作業位置Ｍと上限設定位置Ｈは切替スイッチ３１で選択が可能であるが、各々の位置で停止させても良い。その後、昇降スイッチ２２をＯＮ操作すると、昇降体２は一気に下限設定位置Ｌまで下降する。
【００１０】
昇降体２の昇降速度Ｖは、テーブル１３上の荷物の有無や重量、又は昇降体２が上昇中か下降中かの条件によって異なり、昇降速度Ｖは、荷物有りの下降時、空荷の下降時、空荷の上昇時、荷物有りの上昇時の順に遅くなるので、リミットスイッチ２４，２５，２６，２７のカムローラ３０位置に対する昇降枠１２のカム板２８の停止位置が荷物の有無や上昇、下降の条件によって昇降体２の高さに誤差が生じる。これは、位置検知手段４であるリミットスイッチ２４，２５，２６，２７が検知後も、モータ１への慣性力によって昇降体２が完全に停止するまでの移動量が大きくなり、特に荷物が有る状態で昇降体２下降中に、この昇降体２を停止させる場合の移動量が最も多くなる。そこでリミットスイッチ２４，２５，２６，２７が検知状態になるとモータ１を逆転制動させて、昇降体２を短時間で確実に停止させるよう構成してある。この構成により、リミットスイッチ２４，２５，２６，２７を作動させるカム板２８の上下長さを短くすることができるとともに、昇降体２の昇降速度Ｖを高速にしても昇降条件により発生する昇降体２停止位置の誤差を少なくすることが可能である。
【００１１】
昇降体２の荷物の有無はモータ１駆動電流Ｉの大小を検出し所定電流値Ｉａと比較することで判断してある。すなわち、モータ１の駆動電流Ｉが所定電流値Ｉａ以上の場合には荷物有りと判断し、所定電流値Ｉａ未満の場合には空荷と判断する荷物判断手段５を設けてある。
荷物が有る状態で昇降体２を上昇させて停止する場合は、昇降体２に加わる重力が大きいため、モータ１への慣性力は少なくなり、位置検知手段４が作動してから昇降体２が停止するまでの時間は自ずと短いので、この時はモータ１への逆転制動信号を出力しないようにしてある。ただし、モータ１の駆動電流Ｉで荷物の有無を判断すると、モータ１の駆動開始時の駆動電流Ｉは高く、図７、図８に示すように空荷状態であっても荷物が有る状態と略同程度の駆動電流Ｉが流れることから、モータ１駆動開始直後は、例えば昇降体２が空荷状態であったとしても荷物判断手段５が荷物有りという誤った判断を行うこととなる。駆動電流Ｉが所定電流値Ｉａよりも低くなった後に昇降体２を停止させる場合には荷物判断手段５が空荷状態であるという正しい判断を行うことが可能であるが、例えば図３に示すようにモータ１駆動開始直後に昇降体２を停止させたい場合、すなわち昇降体２を少しだけ上昇して停止させたい場合に、実際は空荷でありながらも荷物判断手段５が荷物有りの誤った判断を行い、モータ１が逆転制動を行わず、昇降体２が停止させたい高さ位置よりも上方で停止することとなり、オーバーリミット状態（図４）に至ることもある。そこでモータ１駆動電流Ｉの大小によって荷物の有無を判断する荷物判断手段５の構成では、モータ１駆動開始後、所定時間Ｔ経過前に次のリミットスイッチが作動するという場合は、荷物判断手段５の判断結果にかかわらず、モータ１への逆転制動信号を出力して昇降体２を短時間で停止すべく制御してある。これにより荷物判断手段５の誤認による昇降体２停止位置の誤差が少なくなり、オーバーリミット状態の回避が可能である。
尚、昇降体２にリミットスイッチ等を設け、荷物の有無をリミットスイッチのＯＮ，ＯＦＦで判断する構成や、荷物重量を計測して荷物の有無を判断する構成等により、モータ１駆動前に荷物の有無が判断可能な荷物判断手段５を用いた場合には、荷物有りの状態で昇降体２上昇後、停止させる条件の時にのみモータ１の逆転制動を行わない制御をすれば良い。
【図面の簡単な説明】
【図１】本発明の一部断面側面図。
【図２】本発明の一部断面正面図。
【図３】本発明の要部の側面図。
【図４】本発明の要部の側面図。
【図５】本発明の実施例を示すブロック図。
【図６】本発明の実施例を示すフロー図。
【図７】本発明のモータ駆動電流を示すタイムチャート
【図８】本発明のモータ駆動電流を示すタイムチャート。
【符号の説明】
１モータ
２昇降体
３制御手段
４位置検知手段
５荷物判断手段
Ｉ駆動電流[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a lifting device capable of lifting and lowering a loaded or suspended luggage by lifting and lowering a lifting body, and more particularly to a lifting and lowering control device for a lifting body that is raised and lowered by driving a motor. It is.
[0002]
[Prior art]
[Patent Document 1] Japanese Utility Model Application Laid-Open No. 6-35297 discloses an elevating workbench for lifting a grain storage bag of rice, wheat, or the like to an appropriate height. This means that after placing the cereal storage bag on the bag stand which is kept at the lower limit, the bag stand is raised, and the bag stand is stopped at a height at which the bag knot is easy or at a height which is easy to carry out, for example. It is something that can be done. Each stop position of the bag mounting table is detected by a detector, and in the example of the cited document 1, the detecting unit provided on the back wall of the bag mounting table turns on the limit switch on the column side to stop the bag mounting table. Configuration.
In order to increase the working efficiency of the lifting device, it is effective to increase the lifting speed, but in that case, after the detection unit of the bag platform turns on the limit switch and outputs the stop signal of the drive motor, The bag mount further moves due to the action of the inertial force, so that the amount of movement until it stops completely increases, and the height at which the bag mount stops at the loading state and the empty state differ. There was something. The error in the stop position of the bag mounting table is the largest when the load is increased and when the load is lowered. Further, even if the detecting section turns on the limit switch, the bag placing table does not stop immediately, and the over-limit state in which the detecting section passes through the operating range of the limit switch and the limit switch turns off again is eliminated. Therefore, the operating plane of the detection unit for turning on the limit switch must be configured to be long, and the control of stopping the bag placing table in the middle of this operating plane, that is, raising and lowering the bag placing table a little, and stopping the operation. It was difficult.
[0003]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned disadvantages and to provide a lifting control device of a lifting device with high working efficiency in which a large error does not occur in a stop position of a lifting member due to a difference in lifting conditions.
[0004]
[Means for Solving the Problems]
The invention according to claim 1 includes an elevating body 2 that can be raised and lowered by driving a motor 1, a control unit 3 that controls the driving of the motor 1, and a position detection unit 4 that stops the elevating body 2 at a predetermined height. When the position detecting means 4 is in the detecting state during the elevating and lowering of the elevating body 2, the control means 3 outputs a reverse braking signal to the motor 1 to stop the elevating body 2 in a short time. The configuration of the elevating control device is characterized.
The invention according to claim 2 is provided with a baggage determination unit 5 for determining the presence or absence of a baggage in the elevating body 2, and when the ascent / descent body 2 is lifted in a state where there is a baggage, the position detection unit 4 becomes a detection state. However, the control means 3 does not output a reverse rotation braking signal to the motor 1, so that the control means 3 has a configuration of a lift control device.
According to a third aspect of the present invention, in the baggage judging means 5 for judging the presence or absence of a baggage in the elevating body 2 based on the magnitude of the motor 1 driving current I, the position detecting means 4 is provided before the elapse of a predetermined time T after the motor 1 starts driving. In the detection state, the control unit 3 outputs a reverse braking signal to the motor 1 irrespective of the judgment result of the baggage judging unit 5, so that the lifting / lowering control device is configured.
[0005]
Function and effect of the present invention
According to the first aspect of the present invention, when the position detecting means 4 is in the detection state during the elevating and lowering of the elevating body 2, the control means 3 outputs a reverse rotation braking signal to the motor 1 to move the elevating and lowering body 2 in an extremely short time. Since the lifting / lowering body 2 can be stopped, the lifting / lowering speed of the lifting / lowering body 2 can be increased, the error of the stop position of the lifting / lowering body 2 is small, and the lifting / lowering body 2 is reliably stopped without being in an over-limit state. Can be performed, and the lifting control with good working efficiency can be performed.
According to the second aspect of the present invention, there is provided a baggage judging means 5 for judging the presence or absence of the luggage in the elevating body 2, and when the elevating body 2 is lifted in a state where the luggage is present, the position detecting means 4 detects the luggage state. After that, the control means 3 does not output the reverse rotation braking signal to the motor 1. This is because when the lifting body 2 in a state where a large downward gravity is applied is lifted and stopped, the action of the inertial force on the motor 1 is small, and when the motor 1 is reversely braked at this time, the lifting body 2 The inconvenience of stopping at a position different from the stop position when the robot is lowered can be eliminated, and the error of the stop position due to the elevating condition of the elevating body 2 can be further reduced.
According to the third aspect of the present invention, the luggage judging means 5 for judging the presence or absence of the luggage in the elevating body 2 based on the magnitude of the driving current I of the motor 1 judges that the luggage is present when the driving current I of the motor 1 is large. When the predetermined current value is small, it is determined that the load is empty. However, since the drive current I immediately after the start of the motor 1 is large regardless of the presence or absence of the load, the load determination means 5 can be started even when the ascent is started in an empty state. Makes an erroneous determination that there is a luggage. At this time, if the amount of elevating until the elevating body 2 is raised and stopped is small, the luggage determination means 5 determines that there is luggage, and the control means 3 Without outputting the reverse rotation control signal to the motor 1, the lifting / lowering body 2 stops at a position higher than the position at which it is desired to stop, and may reach an over-limit state. In the present invention, if the position detection means 4 is in the detection state before the predetermined time T has elapsed since the motor 1 is driven and the lifting / lowering body 2 starts ascending, regardless of the judgment result of the baggage judgment means 5, Since the control means 3 outputs a reverse braking signal to the motor 1 and stops the elevator 2 reliably in a short time, errors in the stop position due to the presence of luggage in the elevator 2 and conditions in the direction of lifting are reduced. Can be.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, a pillar 11 of a square pipe material is erected upward from a square base 10 in a plan view, and a vertically movable body 2 is provided along the pillar 11. The support 11 includes a first support 11a at the front and a second support 11b arranged side by side behind the support 11a. The lift frame 12 of the lifting body 2 has a shape surrounding the first support 11a. A table 13 protruding toward the front is provided, and a grain bag, cardboard or the like is placed on the table 13 so that the table 13 can be moved up and down.
The upper ends of the second columns 11b arranged side by side behind the first columns 11a are connected by connecting members 14. An output portion of the motor 1 for driving the elevating body 2 up and down is arranged between the lower end of the second support 11b and the base 10, and curved connecting rods 15 are provided on both left and right sides of the lower end of the second support 11b. The rear end is welded to the base 10 and the front end is welded to the lower part of the first support 11a.
[0007]
A drive sprocket 17 is mounted on the output shaft 16 of the motor 1 located below the support 11, and a driven sprocket 18 is supported on the connecting member 14 at the upper end of the support 11, and the drive sprocket 17 and the driven sprocket 18 The outer peripheral rear end is located in the center of the inside of the second pipe 11b having a square pipe shape, and a chain 19 is wound between the driving sprocket 17 and the driven sprocket 18. That is, the chain 19 is inserted through the inside of the second support 11b to prevent dust and dirt from adhering to the chain 19. Both ends of the chain 19 are connected to the rear side of the elevating body 2 so that the elevating body 2 can move up and down as the motor 1 rotates. In the present embodiment, AC is used as the drive power source for the motor 1, but it may be driven by a DC power source from a battery or the like. Reference numeral 20 denotes a spring that repels the loose side of the chain 19, and reference numeral 21 denotes an adjustment screw that adjusts the resilience of the spring 20. An elevating switch 22 protruding left and right is provided at an intermediate height position of the column 11, and by operating the elevating switch 22, an elevating operation of the elevating body 2 can be performed. The control means 3 is provided in a control box 23 attached to the lower rear portion of the second support 11b, and can control the drive of the motor 1 and other controls of the entire lifting device. Reference numeral 33 above the control box 23 is a power switch.
[0008]
Position detecting means 4 for detecting the position of the elevating body 2 is provided on one of the left and right sides of the second support 11b. In the present embodiment, each position is detected by limit switches 24, 25, 26, and 27. I have. Each of the limit switches 24, 25, 26, and 27 includes a limit switch 24 at an upper limit setting position H for raising the elevating body 2 to the shoulder height of a person, and a limit for an intermediate work position M suitable for carrying the product up to waist height. It comprises a switch 25, a limit switch 26 at a bag knotting position F suitable for connecting a bag mouth of a grain bag or the like, and a limit switch 27 at a lower limit setting position L, which is the lowermost end, and protrudes from the rear of the elevating frame 12. When the cam plate 28 moves up and down, the limit switches 24, 25, 26 and 27 are operated. Each of these limit switches 24, 25, 26, 27 is configured to be able to change the vertical mounting height position according to the working conditions. Reference numeral 29 denotes a cover which is formed in a box shape and covers both left and right outer sides of the first support 11a and the second support 11b.
[0009]
When the elevating switch 22 in the upper and lower middle part of the column 11 is operated, the motor 1 is driven to move the elevating body 2 up and down. The operation method of the elevation switch 22 and the stop position of the elevation body 2 may be appropriately selected according to the work mode. The elevation switch 22 may be provided at any other position, and may be changed to a foot-operated switch or the like.
Next, the control of the elevating device will be described with reference to FIGS. First, the elevating body 3 is stopped at the lower limit setting position L. At this time, the lower limit switch 27 is in an ON state, and is in a standby state before an article is placed. When a predetermined amount (approximately 30 kg) of rice is put into the bag by the sorting machine, the operator places the rice bag on the table 13 of the elevating body 2 and turns on the elevating switch 22. The elevating switch 22 is turned on only once when it is tilted downward. Even if the elevating switch 22 returns to the original horizontal state, the ON operation is maintained and the motor 1 is driven. When the elevating body 2 starts to move up together with the rice bag, the lower limit switch 20 is turned off, and the elevating body 2 moves up and reaches the bag knotting position F, that is, the cam plate 28 at the rear of the elevating body 2 activates the limit switch 26. When turned on, the driving of the motor 1 stops. At this position, the worker ties the string at the mouth of the bag, drops the rice bag on the table 13, and turns on the elevating switch 22 again. Then, the elevating body 2 rises again, and stops at the intermediate working position M of the waist height where the limit switch 25 is turned on or at the upper limit setting position H of the shoulder height where the limit switch 24 is turned on. In the present embodiment, the intermediate work position M and the upper limit setting position H can be selected by the changeover switch 31, but may be stopped at each position. Thereafter, when the lifting switch 22 is turned ON, the lifting body 2 is immediately lowered to the lower limit setting position L.
[0010]
The elevating speed V of the elevating body 2 differs depending on the presence or absence and weight of luggage on the table 13 or the condition of whether the elevating body 2 is moving up or down. In this case, the stop position of the cam plate 28 of the lift frame 12 with respect to the position of the cam roller 30 of the limit switches 24, 25, 26, 27 is determined by the presence or absence of the load, An error occurs in the height of the elevating body 2 depending on the condition of the descent. This is because, even after the limit switches 24, 25, 26, and 27, which are the position detecting means 4, detect the amount of movement until the lifting / lowering body 2 is completely stopped by the inertial force to the motor 1, and especially there is a load. In this state, while the elevating body 2 is descending, the amount of movement when stopping the elevating body 2 is the largest. Therefore, when the limit switches 24, 25, 26, and 27 are in the detection state, the motor 1 is reversely braked, and the lifting / lowering body 2 is reliably stopped in a short time. With this configuration, the vertical length of the cam plate 28 that operates the limit switches 24, 25, 26, and 27 can be reduced, and the elevating body generated under the elevating condition even when the elevating speed V of the elevating body 2 is increased. It is possible to reduce the error of the two stop positions.
[0011]
The presence or absence of the luggage in the elevating body 2 is determined by detecting the magnitude of the driving current I of the motor 1 and comparing it with a predetermined current value Ia. That is, there is provided a baggage judging means 5 for judging that there is a baggage when the driving current I of the motor 1 is equal to or more than the predetermined current value Ia, and judging that there is an empty baggage when the driving current I is smaller than the predetermined current value Ia.
When the elevator 2 is lifted and stopped in a state where there is luggage, the gravity applied to the elevator 2 is large, the inertia force to the motor 1 decreases, and the elevator 2 is activated after the position detecting means 4 is operated. Since the time until the motor stops is naturally short, no reverse braking signal is output to the motor 1 at this time. However, when the presence / absence of a load is determined based on the drive current I of the motor 1, the drive current I at the start of driving the motor 1 is high, and as shown in FIGS. Since approximately the same drive current I flows, immediately after the start of driving of the motor 1, for example, even if the elevating body 2 is in an empty state, the baggage judging means 5 makes an erroneous judgment that there is a baggage. When stopping the elevating body 2 after the drive current I becomes lower than the predetermined current value Ia, it is possible to make a correct determination that the baggage determination means 5 is empty, for example, as shown in FIG. Thus, when it is desired to stop the elevating body 2 immediately after the motor 1 starts to be driven, that is, when the elevating body 2 is to be slightly lifted and stopped, the baggage judging means 5 may erroneously indicate that there is a luggage even though it is actually empty. By making a determination, the motor 1 does not perform reverse rotation braking, and the lifting / lowering body 2 stops above the height position at which it is desired to stop, which may lead to an over-limit state (FIG. 4). Therefore, in the configuration of the baggage determination means 5 for determining the presence or absence of a baggage based on the magnitude of the motor 1 drive current I, if the next limit switch is activated before the predetermined time T elapses after the motor 1 is started, the baggage determination means 5 Irrespective of the judgment result, the control is performed so as to output the reverse rotation braking signal to the motor 1 and stop the elevating body 2 in a short time. As a result, the error of the stop position of the lifting / lowering body 2 due to erroneous recognition of the baggage judging means 5 is reduced, and the over-limit state can be avoided.
A limit switch or the like is provided on the elevating body 2 to determine the presence / absence of luggage by ON / OFF of the limit switch, or to measure the luggage weight to determine the presence / absence of luggage. If the luggage determination means 5 capable of determining the presence or absence of the load is used, control may be performed such that the reverse rotation braking of the motor 1 is not performed only under conditions of stopping after the lifting body 2 is lifted with luggage.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional side view of the present invention.
FIG. 2 is a partial cross-sectional front view of the present invention.
FIG. 3 is a side view of a main part of the present invention.
FIG. 4 is a side view of a main part of the present invention.
FIG. 5 is a block diagram showing an embodiment of the present invention.
FIG. 6 is a flowchart showing an embodiment of the present invention.
FIG. 7 is a time chart showing a motor drive current of the present invention. FIG. 8 is a time chart showing a motor drive current of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Motor 2 Elevating body 3 Control means 4 Position detecting means 5 Baggage judging means I Drive current

Claims

A vertically movable body (2) driven by a motor (1), a control means (3) for controlling the drive of the motor (1), and a position detecting means () for stopping the vertically movable body (2) at a predetermined height. 4), the control means (3) outputs a reverse braking signal to the motor (1) when the position detecting means (4) is in the detecting state during the elevating and lowering of the elevating body (2). An elevating control device for controlling the elevating body (2) to stop in a short time.

A luggage determining means (5) for determining the presence or absence of luggage in the elevating body (2) is provided. 2. The lift control device according to claim 1, wherein the control means (3) does not output the reverse rotation braking signal to the motor (1) when the detection state is detected.

In the load determining means (5) for determining the presence or absence of a load on the elevating body (2) according to the magnitude of the drive current (I) of the motor (1), the position is detected before the lapse of a predetermined time (T) after the start of the motor (1). The control means (3) outputs a reverse braking signal to the motor (1) when the means (4) enters the detection state, irrespective of the judgment result of the baggage judgment means (5). Item 3. The elevation control device according to Item 2.