Mazda Motor Corporation

Nippon Thermostat Co., Ltd.

Tatsuya Takahata

Shinji Watanabe

Keita Watanabe

Tetsuya Nishimura

Mikimasa Kawaguchi

Keiichi Miyamoto

Takayuki Tominaga

Yoshiaki Hayamizu

Kouichi Miyamoto

Tomokuni Kusunoki

Takafumi Nishio

Yasushi Nakahara

Tomohiro Koguchi

Ryotaro Nishida

Kouji Shishime

Yoshitaka Wada

Akihiro Noda

Naoki Nagano

Hiroshi Kinoshita

Shinji Fujihira

Nobuhiko Yokoyama

Shinichi Hikitani

Masanobu Koutoku

Toshinori Ueno

Takashi Kariya

Katsuya Murakami

Yuichi Ayukawa

Hajime Umehara

Takayoshi Fujita

Junichi Seguchi

A thermostat device is provided that smoothens the flow of the coolant to keep the pressure loss small and can sufficiently secure the flow rate of the coolant from the radiator side to the engine side. A housing having a first inlet for introducing a coolant cooled by a radiator and a coolant outlet supplied to the internal combustion engine, a thermo-element accommodated in the housing that moves axially depending on the temperature of the coolant, a control valve that controls the amount of coolant introduced from the first inlet as the thermoelement moves in the axial direction, and a slope having an upward slope from the outlet side to the valve seat side inside the exit-side conduit extending from the valve seat in the housing, wherein the control valve is in contact with in the valve-closed state, toward the flow outlet of the coolant, are provided.

Thermostat device

The thermostat device includes a housing including a first flow inlet that receives a coolant from a radiator, a second flow inlet that receives a coolant through a bypass passage, and a flow outlet of coolant in which each coolant is mixed; a thermo-element that is accommodated in the housing and moves in an axial direction depending on a temperature of the coolant from the second flow inlet; a control valve that controls amount of the coolant introduced from the first flow inlet as the thermo-element moves; a valve seat that is formed at a tip portion of an annular protrusion formed to protrude in a moving axis direction of the thermo-element in the housing and with which the control valve is in contact in a valve-closed state; and an annular groove formed by an annular gap provided outside of the valve seat and continuous in a circumferential direction.

A thermostat device ensures a coolant amount from a bypass passage sufficiently and excellent temperature sensitivity to the coolant temperature. The thermo-operating unit is provided with a control valve for controlling an introduced coolant amount from a first flow inlet via a radiator, corresponding to the temperature of the coolant from a second flow inlet via a bypass passage. Within the housing are provided multiple guides, which are formed extending from the second flow inlet side toward a thermo-element, are arranged intermittently around the thermo-element, and support the thermo-element slidably movable in an axial direction and coolant rectifying protrusions arranged spaced apart from the thermo-element between the guides, wherein a detoured passage for the coolant, directed from the second flow inlet side toward an outflow port, is formed by forming gaps between the guides and the coolant rectifying protrusions.

An engine EGR system is provided, which includes an engine body, an intake passage, an exhaust passage and an EGR passage configured to recirculate exhaust gas as EGR gas to the intake passage. The EGR passage includes an EGR cooler and an EGR internal passage constituting the EGR passage upstream of the EGR cooler, and including a passage passing through a cylinder head. The EGR internal passage has a bent pipe part including a first bent portion at which an upstream portion of the EGR internal passage is bent away from a gas inflow port of the EGR cooler, a second bent portion located downstream of the first bent portion and bending the EGR internal passage toward the gas inflow port, and an intermediate portion connecting the first and the second bent portions by being disposed therebetween. The water-cooling passage is disposed around the bent pipe part.

EGR system of engine

A compression ignition engine with a supercharger is provided, which includes one or more valves configured to switch a state between a first state where intake air is boosted by the supercharger and a second state where it is not boosted, a fluid temperature adjuster configured to adjust a temperature of engine coolant to be supplied to a radiator from an engine body, and a controller. When the engine operates in a high-load range, the controller controls the combustion mode to be in a compression ignition combustion mode, and causes the valve(s) to be in the first state, and in a low-load range, the controller causes the valve(s) to be in the second state. In the high-load range, the controller outputs a control signal to the fluid temperature adjuster so that a target temperature of the engine coolant is lowered than that in the low-load range.

Compression ignition engine with supercharger

Provided is an engine cooling apparatus capable of preventing deterioration in reliability of a cylinder head of an engine during cold engine operation. The engine cooling apparatus comprises an engine cooling water path, a heater core cooling path, and a radiator cooling water path, and further comprises a switching valve for switching among these cooling water paths. The switching valve is operable, when the temperature of an area around an exhaust valve is raised to a value greater than, e.g., 150&#xb0; C., even in a situation where the temperature of cooling water for cooling the engine is equal to or less than, e.g., 50&#xb0; C., to switch from the in-engine cooling water path to the heater core cooling water path.

Engine cooling apparatus

An engine cooling structure includes a cylinder block including a block inner peripheral wall and a block outer peripheral wall that define a water jacket, and a spacer housed in the water jacket. The block outer peripheral wall includes a coolant inlet for introducing a coolant into the water jacket at one end in a cylinder row direction. The spacer includes a peripheral wall surrounding the block inner peripheral wall, and a dividing wall and a distribution wall provided on the peripheral wall. The dividing wall is provided along a circumferential direction of the peripheral wall and protrudes outward from the peripheral wall between a lower end and an upper end of the coolant inlet. The distribution wall includes an upper distribution wall extending upward from the dividing wall and a lower distribution wall extending downward from the dividing wall.

Engine cooling structure

An engine cooling structure includes a cylinder block including a block inner peripheral wall that defines a water jacket and a block outer peripheral wall, a spacer housed in the water jacket, and a cooler provided outside the engine body. The spacer includes: a peripheral wall surrounding the block inner peripheral wall; and a dividing wall protruding from the peripheral wall to divide the water jacket into an upper passage and lower passages below the upper passage. A coolant introduced from a coolant inlet into the upper passage passes through an inter-bore part of the block inner peripheral wall. The coolant in the lower passages is introduced into the cooler through a coolant exit.

A head-side jacket through which coolant flows is formed in a cylinder head. A main circulation path and a sub circulation path through which coolant fed from a coolant pump respectively circulates are formed. The head-side jacket is separated into an exhaust-port side jacket formed around an exhaust port, and a combustion-chamber-side jacket closer to a combustion chamber than the exhaust-port-side jacket. A heat exchanger is not formed in the main circulation path including the combustion-chamber-side jacket, but is formed in the sub circulation path excluding the combustion-chamber-side jacket and including the exhaust-port-side jacket.

Cooling device for engine

Provided are a variable valve timing mechanism, an oil pump supplying oil to a hydraulically-actuated device including the variable valve timing mechanism, and a hydraulic control valve which controls oil pressures supplied to a locking mechanism (which includes a locking member configured to fix a phase angle of a camshaft relative to a crankshaft) of the variable valve timing mechanism, an advanced angle chamber and a retarded angle chamber. While an oil pressure in a hydraulic path detected by a hydraulic sensor increases, a hydraulic control valve controller adjusts a degree of opening of a hydraulic control valve according to the detected oil pressure at a time of releasing the locking member from a locking state, to reduce the oil pressure to be supplied to the advanced angle chamber or the retarded angle chamber used to change the phase angle of the camshaft relative to the crankshaft.

Device for controlling valve timing of engine

A control system for an engine is provided. The system includes a hydraulically-operated variable valve timing mechanism, a variable oil pump, and a hydraulic-pressure control valve. The variable valve timing mechanism has advance-side and retard-side operation chambers and a locking mechanism. The system includes a hydraulic-pressure sensor for detecting hydraulic pressure within a hydraulic-pressure path, and a pump control device for performing a target hydraulic-pressure control. During a change of an engine operating state in a specific operation of the engine, while an unlocking operation of a locking member of the locking mechanism is performed, the pump control device performs, instead of the target hydraulic-pressure control, a discharge amount restricting control to control the hydraulic pressure to be an upper-limit hydraulic-pressure value or lower, which is an upper limit to perform the unlocking operation.

Control system for engine

A starting device of a spark-ignition multi-cylinder engine is provided. The device includes a multi-cylinder engine body having cylinders, fuel injection valves, ignition plugs, an intake valve drive mechanism for opening and closing intake valves, a hydraulic variable valve phase mechanism for changing a close timing of each intake valve, an engine-driven hydraulic pressure supply source for supplying a hydraulic pressure, and a start controller for controlling the fuel injection valves, the ignition plugs, and the variable valve phase mechanism. When the supplied hydraulic pressure is below a predetermined pressure, the variable valve phase mechanism locks the close timing. When an engine temperature in an engine-start is high, the start controller retards a fuel injection timing of the cylinder on intake stroke at an engine stopped timing and retards an ignition timing thereof. The start controller does not retard the close timing of the intake valve until the engine-start completes.

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Hiroshima, Japan

Tatsuya Takahata