JPH0420876U

JPH0420876U -

Info

Publication number: JPH0420876U
Application number: JP6258390U
Authority: JP
Priority date: 1990-06-12
Filing date: 1990-06-12
Publication date: 1992-02-21
Anticipated expiration: 2005-06-12
Also published as: JPH085901Y2

Description

[Brief explanation of the drawing]

第１図はこの考案に係る操向切換装置の電気回
路図、第２図は油圧回路図、第３図は自走式昇降
作業台の側面図、第４図は一部断面正面図、第５
図は平面図である。符号、４……作業台、６……前輪、７……後輪
、２１……前輪用操向シリンダ、２２……後輪用
操向シリンダ、２９……前輪用操向シリンダ制御
用ソレノイドバルブ、２９Ｌ……同上の伸長側ソ
レノイド、２９Ｒ……同上の縮短側ソレノイド、
３０……後輪用操向シリンダ制御用ソレノイドバ
ルブ、３０Ｌ……同上の伸長側ソレノイド、３０
Ｒ……同上の縮短側ソレノイド、３１……操向切
換スイツチ、３４……前輪用ソレノイド励磁回路
、３５……後輪用ソレノイド励磁回路、３６……
カニ操向スイツチ、３７……二輪操向前後切換ス
イツチ、３８……カニ操向用リレー、３８ａ……
同上の接点、３９……二輪操向前後切換用リレー
、３９ａ……同上の接点、４０……スイツチボツ
クス、４２……当板。 Fig. 1 is an electric circuit diagram of the steering switching device according to this invention, Fig. 2 is a hydraulic circuit diagram, Fig. 3 is a side view of a self-propelled lifting work platform, Fig. 4 is a partially sectional front view, and Fig. 4 is a partially sectional front view. 5
The figure is a plan view. Code, 4... Workbench, 6... Front wheel, 7... Rear wheel, 21... Steering cylinder for front wheels, 22... Steering cylinder for rear wheels, 29... Solenoid valve for controlling the steering cylinder for front wheels. , 29L... Extension side solenoid as above, 29R... Retraction side solenoid as above,
30... Rear wheel steering cylinder control solenoid valve, 30L... Same as above extension side solenoid, 30
R... Reduction side solenoid same as above, 31... Steering changeover switch, 34... Solenoid excitation circuit for front wheels, 35... Solenoid excitation circuit for rear wheels, 36...
Crab steering switch, 37... Two-wheel steering front/rear switch, 38... Crab steering relay, 38a...
Contact point as above, 39...Relay for switching forward and backward steering of two wheels, 39a... Contact point as above, 40... Switch box, 42... Contact plate.

Claims

[Claims for Utility Model Registration] [1] Solenoid valve 2 that controls expansion and contraction of steering cylinders 21 and 22 for front wheels and rear wheels, respectively.
Steering switch 3 is attached to extension side solenoids 29L, 30L and contraction side solenoids 29R, 30R of 9, 30.
The left and right switching contacts of 1 are connected to form a front wheel solenoid excitation circuit 34 and a rear wheel solenoid excitation circuit 35.
In the self-propelled elevating work platform configured to turn the front and rear wheels 6 and 7 left and right by switching the steering switch 31, the front wheel solenoid excitation circuit 34 has a crab steering switch 36 "on" for two wheels. The contact point 39a of the two-wheel steering front/back switching relay 39, which is energized when the steering front/rear switch 37 is ``forward'', is connected to the rear wheel solenoid excitation circuit 35 when the crab steering switch 36 is ``on'' or the two-wheel steering front/back is energized. Crab steering relay 38 energized by switch 37 “rear”
A steering switching device for a self-propelled elevating work platform formed by connecting the contacts 38a of the above. [2] When the switchbox 40 that accommodates the two-wheel steering forward/backward switching switch 37, etc. is configured to be replaceable at the front and rear parts of the workbench 4, and the switchbox 40 is attached to the rear part of the workbench 4, The steering switching device for a self-propelled elevating work platform according to claim 1, wherein the two-wheel steering forward/backward switching switch 37 contacts the contact plate 42 to switch the two-wheel steering forward/backward switching switch 37 to the "rear" position. .