JPS6093699U

JPS6093699U - Hydraulic circuit of engine-powered forklift

Info

Publication number: JPS6093699U
Application number: JP18733983U
Authority: JP
Inventors: 長倉　宏征
Original assignee: 株式会社日本製鋼所
Priority date: 1983-12-02
Filing date: 1983-12-02
Publication date: 1985-06-26

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of drawings]

第１図は従来のエンジン式フォークリフトの一例を示す
油圧回路図、第２図ａは第１図の従来回路を用いた場合
のエンジン回転数と流量の関係　・を、アイドリング時
、走行時のみ及びリフト下げ作業時について示した特性
線図、第２図すは同じくチルト作業時のみ、リフト上げ
作業時のみ、及びチルトとリフト上げの両作業時につい
て示した特性線図、第３図は本考案のエンジン式フォー
クリフトの一実施例を示す油圧回路図、第４図ａは第３
図の本考案回路を用いた場合のエンジン回転数と流量の
関係を、アイドリング時、走行時のみ及びリフト下げ作
業時について示した特性線図、第４図すは同じ、くチル
ト作業時について示した特性線図、第４図Ｃは同じくリ
フト上げ作業時について示した特性線図、第４図ｄは同
じくチルト及びリフト上げの両作業時について示した特
性線図−である。１・・・エンジン、２・・・可変容積ポンプ、３・・・
第１絞り、４・・・圧力制御弁、５・・・フロープライ
オリティ弁、６・・・第１管路、７・・・第２管路、８
・・・パワー　−ステアリングシリンダ、９・・・パワ
ーステアリング用切換弁、１０・・・チルトシリンダ、
１１・・・リフトシリンダ、１２・・・チルト用切換弁
、１３・・・リフト用切換弁、１２ａ、１３ａ・・・常
時閉の第１ポート、１２ｂ、１３ｂ・・・常時閉の第２
ポート、１４・・・タンク、１７・・・第２絞り、１８
・・・可変容積ポンプ２の吐出量制御装置、１９．２０
・・・第３、第４管路、２１．２２・・・第５、第６管
路、２３・・・第３第３図 □□□− □二二二一１１７−ノ川」第４図ノ２フイドリシブ）１＋ス蚤ダー久　　Ｘ。 −ｋｉｏ工じ禾転豊Fig. 1 is a hydraulic circuit diagram showing an example of a conventional engine-powered forklift, and Fig. 2a shows the relationship between engine speed and flow rate when using the conventional circuit shown in Fig. 1. Figure 2 shows the characteristic diagram for the lift lowering operation, Figure 2 shows the characteristic diagram for only the tilting operation, only the lifting operation, and both the tilting and lifting operation. Figure 3 shows the characteristic diagram for the present invention. Fig. 4a is a hydraulic circuit diagram showing an example of an engine-driven forklift truck.
Figure 4 is a characteristic diagram showing the relationship between engine speed and flow rate when the circuit of the present invention is used during idling, only when driving, and when lowering the lift. FIG. 4C is a characteristic diagram similarly shown for the lifting operation, and FIG. 4D is a characteristic diagram similarly shown for both the tilting and lifting operations. 1... Engine, 2... Variable displacement pump, 3...
First throttle, 4... Pressure control valve, 5... Flow priority valve, 6... First pipe line, 7... Second pipe line, 8
... Power-steering cylinder, 9... Power steering switching valve, 10... Tilt cylinder,
DESCRIPTION OF SYMBOLS 11... Lift cylinder, 12... Tilt switching valve, 13... Lift switching valve, 12a, 13a... Normally closed first port, 12b, 13b... Normally closed second port
Port, 14...Tank, 17...Second throttle, 18
...discharge rate control device for variable displacement pump 2, 19.20
...3rd and 4th pipelines, 21.22...5th and 6th pipelines, 23...3rd figure Figure No. 2 Fidelisib) 1 + Scarlet X. -kio

Claims

[Claims for Utility Model Registration] A variable displacement pump 2 driven by an engine 1, and a first pipe line 6- and a second pipe line 7 for discharging oil from the variable displacement pump 2.
a flow priority valve 5 having a first throttle 3 on the side of the first pipe 6; a power steering cylinder 8 connected to the first pipe 6 via a power steering switching valve 9; Tilt and lift switching valve 1 on road 7
2. Tilt cylinder 1 connected via 13 respectively
0 and a lift cylinder 11, the discharge side of the variable displacement pump 2 and the flow priority valve 5.
A second throttle 17 is inserted between the inflow side of the first throttle 3 of and the normally closed first switch valve for tilt and lift.
3rd port between ports 12a and 13a. A normally closed second boat 12 connected by a fourth pipe 19.20 and connected to the outflow side of the second throttle 17 and the tilt/lift switching valve 12.13.
5.b and 13b, respectively. 6th pipeline 21.22
A third throttle 23 is inserted into the fifth pipe line 21, and a third throttle valve is inserted into the tilt and lift switching valves 12 and 13 when these are respectively switched to the tilt operation position and the lift-up operation position. , a passage 24a for communicating the fourth conduit 19.20 with the fifth and sixth conduit 21.22, respectively;
A hydraulic circuit for an engine-type forklift truck, characterized in that it is configured by providing 24b and 25.