Mazda Motor Corporation

Nippon Thermostat Co., Ltd.

Keita Watanabe

Tatsuya Takahata

Shinji Watanabe

Tetsuya Nishimura

Mikimasa Kawaguchi

Takayuki Tominaga

Yoshiaki Hayamizu

Tomohiro Koguchi

Ryotaro Nishida

Yuichi Ayukawa

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 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.

Growing community of inventors

Hiroshima, Japan

Keita Watanabe