JPH0187932U

JPH0187932U -

Info

Publication number: JPH0187932U
Application number: JP1987185288U
Authority: JP
Priority date: 1987-12-03
Filing date: 1987-12-03
Publication date: 1989-06-09

Description

[Brief explanation of the drawing]

第１図はこの考案を具体化したクラツチ油圧制
御装置の油圧回路図、第２図は非インチング操作
時におけるインチングバルブの断面図、第３図は
インチンペダルを最大に踏み込んだ時のインチン
グバルブの断面図、第４図はインチング操作時の
インチングバルブの断面図、第５図は第２の流出
ポートから送油される圧力流体の圧力と車速との
関係を示す図、第６図は従来のクラツチ油圧制御
装置の油圧回路図である。図中、１２は弁室、１３は第１の流入ポート、
１４は第１の流出ポート、１５は第２の流入ポー
ト、１６は第２の流出ポート、１７はドレインポ
ート、１８はインチングスプール、２０はインチ
ングピストン、２１はインチングスプリング、２
５は減圧手段としてのリリーフ弁、３０は走行用
エンジン、３１はオイルポンプ、３２はレギユレ
ータバルブ、３３はインチングバルブ、３５，３
６，４０，４１は管路、３９はインチング操作装
置としてのインチングペダル、４２はセレクタバ
ルブ、４３はクラツチ切換操作装置、４４は前後
進クラツチ、Ｔはタンクである。 Figure 1 is a hydraulic circuit diagram of a clutch hydraulic control system embodying this idea, Figure 2 is a sectional view of the inching valve during non-inching operation, and Figure 3 is the inching valve when the inching pedal is fully depressed. Figure 4 is a cross-sectional view of the inching valve during inching operation, Figure 5 is a diagram showing the relationship between the pressure of the pressure fluid sent from the second outflow port and the vehicle speed, and Figure 6 is the conventional FIG. 2 is a hydraulic circuit diagram of a clutch hydraulic control device. In the figure, 12 is a valve chamber, 13 is a first inflow port,
14 is a first outflow port, 15 is a second inflow port, 16 is a second outflow port, 17 is a drain port, 18 is an inching spool, 20 is an inching piston, 21 is an inching spring, 2
5 is a relief valve as a pressure reducing means, 30 is a driving engine, 31 is an oil pump, 32 is a regulator valve, 33 is an inching valve, 35, 3
Reference numerals 6, 40, and 41 are conduits, 39 is an inching pedal as an inching operation device, 42 is a selector valve, 43 is a clutch switching operation device, 44 is a forward/reverse clutch, and T is a tank.

Claims

[Claims for Utility Model Registration] 1. An oil pump rotatably driven by a driving engine, a clutch whose connection state is controlled by the pressure of pressure fluid, and a clutch which is switched by a clutch switching operation device to a selector valve that supplies the pressure of pressure fluid from the pump to the clutch; and a selector valve that is provided upstream of the selector valve and is switched by an inching operation device to supply pressure fluid to the clutch through the selector valve during inching operation. In a clutch hydraulic control device comprising an inching valve that reduces the pressure of the clutch to bring the clutch into a half-clutch state, detecting an increase in the pressure of the pressure fluid supplied from the inching valve to the selector valve during the inching operation; A clutch hydraulic control device includes a pressure reducing means for reducing the pressure of the fluid supplied to the selector valve based on the increase in pressure. 2 The pressure reducing means is a relief valve that reduces the pressure of the pressure fluid sent to the inching valve based on the pressure of the outflow port of the inching valve connected to the selector valve during the inching operation. Clutch hydraulic control device according to scope 1.