Kanzaki Kokyukoki Mfg. Co., Ltd.

Jiro Shibata

Ryota Ohashi

Masahisa Kawamura

Hideki Kanenobu

Shigenori Sakikawa

Toshiro Azuma

Kojiro Yamaoka

Shigenori Sakigawa

Atsushi Odagaki

A valve casing (,) having plural direction control valves (,H,,L,,A,,B,,C) and plural pressure sensors (,H,,L,,A,,B,,C) is mounted on an outer side surface of a vehicle body (,) which includes therein plural fluid-operated clutches (,H,,L,,A,,B,,C) for changing the vehicle running speed. The control valves are secured to the casing from one of upper and lower surfaces thereof and the pressure sensors are secured to the casing from the other of the upper and lower surfaces such that the valves and the sensors are arranged respectively in parallel in a longitudinal direction of the vehicle body. Preferably, the valve casing is composed of an outer plate member (,) to which the control valves and pressure sensors are secured, an inner plate member (,) comprising plural output ports (,H,,L,,A,,B,,C) which are connected respectively to the plural fluid-operated clutches, and a separator member (,) interposed between the plate members and having plural fluid passage bores which connect between fluid passages in the outer plate member and fluid passages in the inner plate member.

Speed change control device in working vehicles

In a vehicle wherein a supplementary speed change mechanism (,) having selectively operable two fluid-operated clutches (,F,,R;,L,,H) and a main speed change mechanism (,) having selectively operable plural fluid-operated clutches (,) are connected in series, and wherein fluid pressure applied to the clutches of supplementary speed change mechanism is once reduced in response to the shifting operation of main speed change mechanism, a flow control valve (,) is connected to an output flow path (,) of a pump (,) for dividing its inflow into a constant flow and a surplus flow. A flow divider valve (,A) is provided for dividing the constant flow into two flows of a constant ratio one of which is supplied to the clutches of main speed change mechanism and the other of which is supplied to the clutches of supplementary speed change mechanism. The surplus flow is used as lubricant supplied to the clutches of supplementary speed change mechanism. In another embodiment employed in a vehicle comprising a supplementary speed change mechanism (,) having selectively operable two fluid-operated clutches (,F,,R) each of which is selectively brought into a slippingly engaged condition by a pressure-reducing valve (,), fluid relieved from a relief valve (,) for determining fluid pressure applied to another fluid-operated device (,) is joined to lubricant for the cluthes.

Fluid supply system in vehicles

A single hydraulic pump (6) is employed in a vehicle for supplementing fluid to a hydrostatic transmission (1) and for supplying fluid to a fluid-operated clutch (2) and to high pressure-actuated hydraulic actuators (3, 4, 5). Fluid discharge path (7) of the pump is connected to the hydrostatic transmission through a pressure-reducing valve (8). Fluid drain path (9) of the reducing valve is fashioned to a fluid supply path for the clutch. A second fluid supply path (11) is connected to the discharge path for supplying fluid to the hydraulic actuators and include a relief valve (12) or orifice (12A) for maintaining fluid pressure in the discharge path higher than the output pressure of the reducing valve. A high pressure relief valve (10) for establishing fluid pressure to be applied to the actuators is connected to the discharge path for minimizing a discharge pressure required to the pump.

Fluid supply system for vehicles

A hydraulic flow divider has first and second flow control valves each dividing its inflow into two flows. The first flow control has a pressure relief valve and a constant orifice dividing flow to two outlets. The second flow control further divides one of these flows into a second set of two output flows. One of the output flows of the second flow control valve is directed to a power steering cylinder while secondary output flow of the second flow control valve joins flow from the other outlet of the first flow control. The arrangement secures adequate fluid supply to a priority load of the hydraulic system at low pump drive engine speeds.

Two-stage flow divider with pressure-relief valves in each stage to

A hydraulic flow divider has first and second (147, 148) flow control valves each dividing its inflow into two flows. The constant orifice first flow control valve (147) divides flow to outlets (151) and (153). Flow from outlet (151) is then divided by the second valve (148). One of the output flows of the second valve is generated by a constant orifice and directed to a power steering cylinder. Any secondary output from the second valve is generated by a pressure relief valve (152), joins flow from outlet (153), and passes to a hydraulic lift cylinder. The arrangement secures a significant flow rate for lift cylinder operation at low pump drive engine speeds at which pump output flow is low.

Two-stage flow divider with constant orifice first stage in hydraulic

In a working vehicle comprising a hydraulic power steering cylinder (25) and hydraulic lift cylinder (31), a novel hydraulic system is employed which comprises first and second flow control valve means (47, 48; 147, 148; 247, 248; 347, 348), each dividing its inflow into two flows. These valve means are connected in a fashion such that output flow of a single pump (43) driven by engine (10) is first divided into two output flows one of which is then divided by the second valve means. Further, one of the output flows of the second valve means is directed towards the steering cylinder whereas the other of output flows of the both valve means are directed towards the lift cylinder. The connection is such that, while a predetermined constant flow is secured for the steering cylinder at the normal engine speeds, a flow is necessarily secured for a relatively quick operation of the lift cylinder already at a low engine speed.

Flow divider valve for hydraulic system in working vehicles

A hydraulic steering system for use in four-wheel running vehicles or the like of small size and low horsepower. The steering system and a hydraulic system for lifting a working implement are both operable by a single hydraulic pump without the necessity of using a variable displacement hydraulic pump or providing two hydraulic pumps for the two systems. The steering system is operable by an engine of low horsepower.

Hydraulic steering system

In a working vehicle comprising a hydraulic power steering cylinder (25) and hydraulic lift cylinder (31), a novel hydraulic system is employed which comprises a flow control valve means (47) having an orifice (51) and relief valve (52) and arranged such that it divides output flow of a single pump (43) driven by engine (10) into a constant flow directed towards steering cylinder and a surplus flow directed towards lift cylinder. Piston (54) is particularly provided which varies, in cooperation with an orifice (55) between the pump and control valve means, the biasing force of valve spring (53) of the relief valve so as to vary the flow directed towards steering cylinder within a predetermined range in response to engine speed. The system is fashioned such that it secures a flow for a relatively quick operation of lift cylinder at a low engine speed while securing a predetermined constant flow for steering cylinder at the normal engine speeds.

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Amagasaki, Japan

Jiro Shibata