Engine water-cooling device

Patent metadata

Field	Value
Publication number	US-9771854-B2
Application number	US-201514842520-A
Country	US
Kind code	B2
Filing date	Sep 1, 2015
Priority date	Sep 29, 2014
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

There is provided an engine water-cooling device that can increase warming-up efficiency of an engine. The engine water-cooling device includes a thermostat housing that houses a thermostat. The thermostat housing is mounted to a front wall of a cylinder head in one side portion in a width direction of the cylinder head. A cooling water pump is mounted to a front wall of a cylinder block in a central portion in a width direction of the cylinder block. A bypass passage includes an intra-head bypass passage in the cylinder head, and the intra-head bypass passage includes a width-direction passage portion extending from a position behind the thermostat housing to a position behind and above the cooling water pump.

First claim

What is claimed is:

1. An engine water-cooling device comprising: an intra-head cooling water jacket in a cylinder head; a thermostat; a bypass passage; a radiator; and a cooling water pump, and
configured such that engine cooling water in the intra-head cooling water jacket flows back to the cooling water pump via the bypass passage bypassing the radiator and when a water temperature of the engine cooling water detected by the thermostat exceeds a predetermined value, the thermostat causes the engine cooling water in the intra-head cooling water jacket to flow back to the cooling water pump via the radiator,
wherein the engine water-cooling device includes a thermostat housing that houses the thermostat, the thermostat housing is mounted to a front wall of the cylinder head in one side portion in a width direction of the cylinder head, the cooling water pump is mounted to a front wall of a cylinder block in a central portion in a width direction of the cylinder block,
the bypass passage includes an intra-head bypass passage in the cylinder head, and the intra-head bypass passage includes a width-direction passage portion extending from a position behind the thermostat housing to a position behind and above the cooling water pump.

2. The engine water-cooling device according to claim 1 ,
wherein the thermostat is of a bottom bypass type, an inside of the thermostat housing is partitioned with a partition wall into an upper thermostat chamber and a lower bottom bypass chamber, a bottom bypass valve orifice is provided in the partition wall, an outlet to the radiator opens on an upper side of the thermostat chamber, an inlet of the thermostat chamber opens on a back side of the thermostat chamber, an outlet of the bottom bypass chamber opens on a back side of the bottom bypass chamber,
an outlet of the intra-head cooling water jacket and an inlet of the bypass passage open on the front wall of the cylinder head,
the thermostat is housed in the thermostat chamber, the bottom bypass valve orifice is configured to be opened and closed by a bottom bypass valve of the thermostat, the outlet of the intra-head cooling water jacket and the inlet of the thermostat chamber overlap and communicate with each other, and the outlet of the bottom bypass chamber and the inlet of the bypass passage overlap and communicate with each other.

3. The engine water-cooling device according to claim 1 ,
wherein an engine cooling fan is disposed in front of the thermostat housing and configured such that engine cooling air is blown backward from the engine cooling fan, and
a heat insulating layer is formed in a front peripheral wall of the thermostat housing.

4. The engine water-cooling device according to claim 3 ,
wherein the heat insulating layer is formed by a hollow air space in the front peripheral wall of the thermostat housing.

5. The engine water-cooling device according to claim 1 ,
wherein a ceiling face of the width-direction passage portion slopes upward toward a position behind the thermostat housing.

6. The engine water-cooling device according to claim 1 ,
wherein the bypass passage includes an intra-block bypass passage in the cylinder block and the intra-block bypass passage communicates with the intra-head bypass passage.

7. The engine water-cooling device according to claim 1 ,
wherein the bypass passage includes a bypass passage outside an engine and the bypass passage outside the engine communicates with the intra-head bypass passage,
the bypass passage outside the engine is a metal pipe provided between the cylinder head and the cooling water pump, and one end portion of the bypass passage outside the engine is fitted in the front wall of the cylinder head.

8. The engine water-cooling device according to claim 7 ,
wherein the engine cooling fan is disposed in front of the bypass passage outside the engine and configured such that the engine cooling air is blown backward from the engine cooling fan, and
an air shielding wall against the engine cooling air is provided in front of the bypass passage outside the engine.

9. The engine water-cooling device according to claim 2 ,
wherein an engine cooling fan is disposed in front of the thermostat housing and configured such that engine cooling air is blown backward from the engine cooling fan, and
a heat insulating layer is formed in a front peripheral wall of the thermostat housing.

10. The engine water-cooling device according to claim 9 ,
wherein the heat insulating layer is formed by a hollow air space in the front peripheral wall of the thermostat housing.

11. The engine water-cooling device according to claim 2 ,
wherein a ceiling face of the width-direction passage portion slopes upward toward a position behind the thermostat housing.

12. The engine water-cooling device according to claim 3 ,
wherein a ceiling face of the width-direction passage portion slopes upward toward a position behind the thermostat housing.

13. The engine water-cooling device according to claim 9 ,
wherein a ceiling face of the width-direction passage portion slopes upward toward a position behind the thermostat housing.

14. The engine water-cooling device according to claim 4 ,
wherein a ceiling face of the width-direction passage portion slopes upward toward a position behind the thermostat housing.

15. The engine water-cooling device according to claim 2 ,
wherein the bypass passage includes an intra-block bypass passage in the cylinder block and the intra-block bypass passage communicates with the intra-head bypass passage.

16. The engine water-cooling device according to claim 3 ,
wherein the bypass passage includes an intra-block bypass passage in the cylinder block and the intra-block bypass passage communicates with the intra-head bypass passage.

17. The engine water-cooling device according to claim 9 ,
wherein the bypass passage includes an intra-block bypass passage in the cylinder block and the intra-block bypass passage communicates with the intra-head bypass passage.

18. The engine water-cooling device according to claim 4 ,
wherein the bypass passage includes an intra-block bypass passage in the cylinder block and the intra-block bypass passage communicates with the intra-head bypass passage.

19. The engine water-cooling device according to claim 5 ,
wherein the bypass passage includes an intra-block bypass passage in the cylinder block and the intra-block bypass passage communicates with the intra-head bypass passage.

20. The engine water-cooling device according to claim 11 ,
wherein the bypass passage includes an intra-block bypass passage in the cylinder block and the intra-block bypass passage communicates with the intra-head bypass passage.

Assignees

• Kubota Kk

Inventors

• Sakurai Naoya
• Koyama Hideyuki
• Goto Hideyuki
• Nagai Kentaro
• Nakano Tadashi

Classifications

• F01P3/02

  Arrangements for cooling cylinders or cylinder heads · CPC title

• F01P2003/024

  Cooling cylinder heads · CPC title

• F01P5/02

  Pumping cooling-air; Arrangements of cooling-air pumps, e.g. fans or blowers · CPC title

• F01P1/06

  Arrangements for cooling other engine or machine parts · CPC title

• F01P7/16 Primary

  by thermostatic control · CPC title